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WO2004088367A1 - Procede de production d'un film a cristaux liquides cholesteriques a large bande, plaque de polarisation circulaire, polariseur lineaire, appareil d'eclairage et dispositif d'affichage a cristaux liquides - Google Patents

Procede de production d'un film a cristaux liquides cholesteriques a large bande, plaque de polarisation circulaire, polariseur lineaire, appareil d'eclairage et dispositif d'affichage a cristaux liquides Download PDF

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Publication number
WO2004088367A1
WO2004088367A1 PCT/JP2004/003791 JP2004003791W WO2004088367A1 WO 2004088367 A1 WO2004088367 A1 WO 2004088367A1 JP 2004003791 W JP2004003791 W JP 2004003791W WO 2004088367 A1 WO2004088367 A1 WO 2004088367A1
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Prior art keywords
liquid crystal
film
plate
polarizing element
light
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PCT/JP2004/003791
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English (en)
Japanese (ja)
Inventor
Takahiro Fukuoka
Miki Shiraogawa
Kentarou Takeda
Naoki Takahashi
Kazutaka Hara
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Nitto Deno Corporation
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Publication of WO2004088367A1 publication Critical patent/WO2004088367A1/fr

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    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/133528—Polarisers
    • G02F1/133536—Reflective polarizers
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/30—Polarising elements
    • G02B5/3016—Polarising elements involving passive liquid crystal elements

Definitions

  • the present invention relates to a method for producing a broadband cholesteric liquid crystal film.
  • the broadband cholesteric liquid crystal film of the present invention is useful as a circularly polarizing plate (reflective polarizer).
  • the present invention relates to a linearly polarizing element, an illuminating device and a liquid crystal display device using the circularly polarizing plate.
  • a liquid crystal display has a structure in which liquid crystal is injected between glass plates on which transparent electrodes are formed, and polarizers are arranged before and after the glass plates.
  • a polarizer used for such a liquid crystal display is manufactured by adsorbing iodine or a dichroic dye on a polyvinyl alcohol film and stretching it in a certain direction.
  • the polarizer thus manufactured itself absorbs light that oscillates in one direction, and passes only light that oscillates in the other direction to produce linearly polarized light.
  • the efficiency of the polarizer cannot theoretically exceed 50%, which is the biggest factor that lowers the efficiency of liquid crystal displays.
  • the liquid crystal display device may destroy the polarizer due to heat generated by the heat conversion of the absorbed light, or may have a negative effect on the liquid crystal layer inside the cell. This causes adverse effects such as deterioration of display quality.
  • Cholesteric liquid crystals with a function of separating circularly polarized light have a selective reflection characteristic that reflects only the circularly polarized light whose wavelength is the helical pitch of the liquid crystal, with the direction of rotation of the liquid crystal helix and the direction of circular polarization being the same. There is.
  • this selective reflection characteristic only specific circularly polarized light of natural light in a certain wavelength band is transmitted and separated, and the remaining light is reflected and reused, whereby a highly efficient polarizing film can be manufactured.
  • the transmitted circularly polarized light is converted into linearly polarized light by passing through a ⁇ / 4 wavelength plate, and the direction of the linearly polarized light is transmitted to the liquid crystal display.
  • a liquid crystal display device with high transmittance can be obtained by adjusting the transmission direction of the absorption polarizer used.
  • a cholesteric liquid crystal film is used as a linear polarizing element in combination with a four-wavelength plate, there is theoretically no loss of light, so a conventional absorption polarizer that absorbs 50% of light In theory, it is possible to obtain twice the brightness improvement as compared with the case where is used alone.
  • the selective reflection characteristic of the cholesteric liquid crystal is limited only to a specific wavelength band, and it has been difficult to perform the power analysis over the entire visible light range.
  • the selective reflection wavelength region width ⁇ of the cholesteric liquid crystal is
  • n o Refractive index of cholesteric liquid crystal molecules for normal light
  • ne Refractive index of cholesteric liquid crystal molecules to extraordinary light
  • the width of the selective reflection wavelength region ⁇ ⁇ can be increased by increasing ne ⁇ no, but ne ⁇ is usually 0.3 or less. If this value is increased, other functions (alignment characteristics, liquid crystal temperature, etc.) of the liquid crystal become insufficient, and practical use was difficult. Therefore, in practice, the width of the selective reflection wavelength region was at most about 150 nm. Most of the practically usable cholesteric liquid crystals are only about 30 to 100 nm. Also, the selective reflection center wavelength is
  • the pitch is constant, it depends on the average refractive index and pitch length of the liquid crystal molecules. Therefore, in order to improve the power of the entire visible light region, a plurality of layers having different selective reflection center wavelengths are laminated, or the pitch length is continuously changed in the thickness direction to form an existence distribution of the selective reflection center wavelength itself.
  • Japanese Unexamined Patent Application Publication No. Hei 6-218184, Japanese Patent No. 3272686, Japanese Unexamined Patent Application Publication No. Hei 11-248943, Japanese Unexamined Patent Application Publication No. See Japanese Patent Publication No. 86953/86.
  • this method when the cholesteric liquid crystal composition is cured by exposure to ultraviolet light, the exposure side and the exit side are exposed. By making a difference in light intensity and making a difference in polymerization rate, the composition ratio of liquid crystal compositions having different reaction rates is changed in the thickness direction.
  • the method of continuously changing the pitch length as disclosed in Japanese Patent Application Laid-Open No. 6-281814 requires a liquid crystal layer thickness of about 15 to 20 ⁇ m necessary for realizing the function.
  • cost was inevitable due to the need for expensive liquid crystals.
  • an exposure time of about 1 to 60 minutes was required, and a long production line with an exposure line length of 10 to 60 Om was required to obtain a line speed of 10 mZ. If the line speed is reduced, the line length can be reduced, but a reduction in production speed is inevitable.
  • Hei 11-248 943 since the mobility of the substance that changes the pitch is better than the material example used in Japanese Unexamined Patent Publication No. Hei 6 A film can be formed with an exposure amount of about a minute. However, even in this case, a thickness of 15 / m is required.
  • Patent No. 3 2 7 2 6 6 8 changes the temperature conditions of the primary exposure and the secondary exposure, and separately provides the time required for the composition ratio to change in the thickness direction, In order to cover substantially the entire visible light region by this method, it is necessary to wait about 120 minutes for mass transfer due to this temperature change.
  • a method of continuously changing the pitch length as disclosed in Japanese Patent Application Laid-Open No. 2002-286935 Requires a liquid crystal layer thickness of about 15 to 20 ⁇ m to exhibit its functions, and in addition to the problem of precise coating of the liquid crystal layer, it also requires a large amount of expensive liquid crystal, which saves cost. I wouldn't.
  • Japanese Patent Application Laid-Open No. 2002-2866935 when the cholesteric liquid crystal composition is cured by ultraviolet exposure from the side opposite to the substrate (air interface side), the cholesteric liquid crystal composition is inhibited by oxygen.
  • the composition ratio change is changed in the thickness direction by making a difference between the exposure intensity on the exposure surface side and the exposure intensity on the emission surface side.
  • the transmission is sufficiently flat for the three emission wavelengths of the backlight source, namely, 355 nm, 545 nm, and 615 nm. It is necessary to ensure the reflectivity and Z-reflectance characteristics.
  • the bandwidth broadening range obtained by the methods of Examples 1 and 2 described in Japanese Patent Application Laid-Open No. 2002-2866935 is 43.5 nm and 615 nm in each case. It was not enough to cover the bright line spectrum. In such a case, the color tone of the transmitted light is difficult to obtain white and cannot be used for a liquid crystal display device or the like. Disclosure of the invention
  • the present applicant has filed a Japanese Patent Application No. 2001-339396.
  • the liquid crystal composition applied to the alignment substrate is irradiated with ultraviolet light from the alignment substrate.
  • polymerization is started from the surface that is not easily affected by polymerization inhibition due to oxygen in contact with the alignment substrate, and an ultraviolet irradiation intensity distribution is formed in the thickness direction by utilizing absorption by the molar absorption coefficient of the liquid crystal layer.
  • the liquid crystal reaction rate gradient and the composition concentration distribution gradient are larger than before by reducing the effective UV radiation on the air surface side, which is greatly affected by oxygen inhibition.
  • a wavelength band of about 400 to 70 nm is used. These wavelength bands power the light source spectrum. These provide good circularly polarized light reflection characteristics near normal incidence. On the other hand, at oblique incidence, the wavelength band was not sufficient.
  • the selective reflection wavelength at oblique incidence is
  • n average refractive index of liquid crystal
  • the selective reflection wavelength shifts to a shorter wavelength side when the light is obliquely incident than when it is perpendicularly incident. Therefore, in order to function effectively for oblique incident light, it is necessary to function in a long wavelength region.
  • An object of the present invention is to provide a method capable of manufacturing a broadband cholesteric liquid crystal film having a broadband reflection band even in a long wavelength region.
  • Another object of the present invention is to provide a circularly polarizing plate using a broadband cholesteric liquid crystal film obtained by the manufacturing method. It is another object of the present invention to provide a linear polarizing element, a lighting device, and a liquid crystal display device using the circular polarizing plate.
  • the present inventors have conducted intensive studies to solve the above problems, and as a result, have found that a broadband cholesteric liquid crystal film that can achieve the above object can be obtained by the following manufacturing method, and have completed the present invention. . That is, the present invention is as follows.
  • the alignment group UV irradiation from the material side (1) In a state where the liquid crystal mixture is in contact with a gas containing oxygen, at a temperature of 20 ° C. or more, at an ultraviolet irradiation intensity of 20 to 200 mWZ cm 2 for 0.2 to 5 seconds, the alignment group UV irradiation from the material side (1),
  • a method for producing a broadband cholesteric liquid crystal film comprising the step of irradiating ultraviolet rays in the absence of oxygen (4).
  • the polymerizable mesogen compound (A) has the following general formula (1):
  • a retardation layer (b) with almost zero front phase difference (normal direction) and a phase difference of ⁇ 8 or more with respect to incident light that is incident at an angle of 30 ° or more with respect to the normal direction is arranged.
  • a polarizing element wherein the reflective polarizer (a) is the circularly polarizing plate according to the above item 6.
  • Retardation layer (b) Force Fixed cholesteric liquid crystal phase having a selective reflection wavelength range other than the visible light range, with fixed planar orientation,
  • a straight line characterized in that a ⁇ / 4 plate is laminated on the circularly polarizing plate described in 6 above or the polarizing element described in any of 7 to 9 above, so that linearly polarized light can be obtained by transmission.
  • Polarizing element
  • the linearly polarizing element according to 10 above obtained by laminating a cholesteric liquid crystal film as a circularly polarizing plate on an e / 4 plate so that the pitch length is continuously narrowed.
  • the 3./4 plate is a liquid crystal polymer type retardation plate obtained by applying and fixing a nematic liquid crystal or a smectic liquid crystal.
  • a linearly polarizing element characterized in that a ⁇ / 2 plate is further laminated on the ⁇ Z 4 plate of the linearly polarizing element according to any of the above 10 to 14.
  • the absorption polarizer whose transmission axis and transmission axis direction of the linear polarizing element according to any of the above 10 to 15 are aligned on the fourth / 4 plate side of the linear polarizing element.
  • a linear polarization element features a linear polarization element.
  • An illumination device comprising a linear polarizing element.
  • a liquid crystal display device comprising a liquid crystal cell on the light emission side of the lighting device according to the above item 17.
  • the viewing angle widening liquid crystal display device according to the above item 19, characterized in that a spreading plate having substantially no backscattering or depolarization is used as the viewing angle widening film.
  • the ultraviolet irradiation condition is such that the first irradiation intensity> the second irradiation intensity, and the first irradiation time ⁇ the second irradiation time.
  • a heating step (3) is provided between the first UV irradiation and the second UV irradiation. Due to the difference in irradiation intensity, the amount of radicals generated by the UV reaction of the photoreaction initiator in the liquid crystal composition per unit time is greatly changed between the first UV irradiation and the second UV irradiation.
  • the first UV irradiation a large amount of radicals are instantaneously formed under monomer-rich conditions at the beginning of the reaction, and a large gradient in the thickness direction is formed in the radical existence distribution due to oxygen inhibition and absorption of the liquid crystal composition.
  • a polymer / oligomer having an average molecular weight of about 1,000 to 5,000 is formed, and a concentration distribution is formed in the thickness direction.
  • the polymerization ratio differs in the thickness direction because the reaction rates of the polymerizable mesogen compound (A) and the polymerizable chiral agent (B) in the liquid crystal composition are different.
  • the surface where the polymerizable chiral agent (B) is rich has a short cholesteric pitch and the surface in the opposite direction becomes long.
  • a cholesteric liquid crystal film having a broad reflection wavelength as a whole can be obtained.
  • the broadband cholesteric liquid crystal film thus obtained functions as a broadband circularly polarizing reflector and has the same optical characteristics as the above-mentioned JP-A-6-218184.
  • the thickness can be reduced by reducing the number of layers compared to the conventional manufacturing method, and furthermore, it can be manufactured easily and in a short time, and the cost is reduced by improving the production speed. Is possible.
  • the broadband cholesteric liquid crystal film obtained by the production method of the present invention has a wide reflection bandwidth of 200 nm or more in the selective reflection wavelength, and has a broadband reflection bandwidth.
  • the reflection bandwidth is preferably at least 300 nm, more preferably at least 400 nm, and further preferably at least 450 nm. Further, it is preferable that the reflection band width of 200 nm or more is provided in a visible light region, particularly in a wavelength region of 400 to 900 nm.
  • a circularly polarizing reflector has a wide reflection band even in a long wavelength region in order to obtain a good viewing angle characteristic of a liquid crystal display device.
  • the long wavelength end of the selective reflection must reach 800 to 900 nm in order to prevent the transmitted light from being colored in a practical viewing angle range.
  • a reflection band is provided even in such a long wavelength region.
  • a broadband cholesteric liquid crystal film can be obtained.
  • Such a broadband cholesteric liquid crystal film is used not only when it is used as a reflective polarizer for obtaining high luminance but also when it is used for a polarizing element formed in combination with another optical element such as a retardation plate.
  • stable optical characteristics for obliquely incident light rays other than the front face are required.
  • FIG. 1 is a conceptual view of a viewing angle widening liquid crystal display device using the polarizing element integrated with a polarizing plate of Examples 1 and 3 and Comparative Examples 1 to 3.
  • FIG. 2 is a conceptual diagram of a viewing angle widening liquid crystal display device using the polarizing plate integrated polarizing element of the second embodiment.
  • FIG. 3 is a diagram illustrating an axis angle of each layer in the polarizing plate integrated polarizing element according to the second embodiment.
  • FIG. 4 is a reflection spectrum of the cholesteric liquid crystal finolem produced in Example 1, Comparative Example 1, and Comparative Example 2.
  • the broadband cholesteric liquid crystal film of the present invention is obtained by ultraviolet polymerization of a liquid crystal mixture containing a polymerizable mesogen compound (A) and a polymerizable chiral agent (B).
  • a polymerizable mesogen compound (A) a compound having at least one polymerizable functional group and having a mesogen group composed of a cyclic unit or the like is preferably used.
  • the polymerizable functional group include an acryloyl group, a methacryloyl group, an epoxy group and a butyl ether group. Of these, an acryloyl group and a methacryloyl group are preferable. It is.
  • a crosslinked structure can be introduced to improve durability.
  • the cyclic unit to be a mesogen group include biphenyl-based, phenylbenzoate-based, phenylsilicone hexane-based, azoxybenzene-based, azomethine-based, azobenzene-based, phenylpyrimidine-based, and diphenyl-based. Ninoleacetylene, diphenylenobenzoate, bicyclohexane, cyclohexylbenzene, terphenyl and the like.
  • the terminal of the cyclic unit may have a substituent such as, for example, a cyano group, an alkyl group, an alkoxy group, or a halogen group.
  • the mesogen group may be bonded via a spacer that imparts flexibility.
  • the spacer include a polymethylene chain and a polymethylene chain. The number of repetitions of the structural unit forming the spacer portion is appropriately determined depending on the chemical structure of the mesogen portion, but the number of recurring units of the polymethylene chain is 0 to 20, preferably 2 to 12, The repeating unit of the methylene chain is from 0 to 10, preferably:! ⁇ 3.
  • the molar extinction coefficient of the polymerizable mesogen compound (A) is 0.1 to 500 dm 3 mol-L e na— [ ⁇ 365 5 1101, and 10 to 300 dm 3 mo 1 _1 cm “is 1 ® 3 3 4 nm, with a force one 1 0 0 0 ⁇ 1 0 0 0 0 0 dm 3 mol -1 cm one 1 @ 3 1 4 nm Dearuko and are preferred.
  • the molar extinction coefficient Molar absorption coefficient is 0.1 ⁇ 50 dm 3 mol- 1 cm- 1 @ 365 nm, 50 ⁇ 100 000 dm 3 mol -1 cm — '2, 100 000 to 500 000 dm 3 mo 1 1 cm— 1 ® 3 14 nm is more preferred
  • the molar extinction coefficient is 0.1 to 10 dm 3 mo 1 _1 cm _ 1 @ 365 nm, 100 0 0 ⁇ 400 m dm 3 mo I- 1 cm-1 1 @ 3 34 nm, 300 0 0 0 ⁇ 400 0 0 dm 3 mo 1 cm "'@ 314 nm is more preferable.
  • Molar extinction coefficient is 0.
  • the molar extinction coefficient is a value obtained by measuring the spectrophotometric spectrum of each material and measuring the resulting absorbance at 365 nm, 334 nm, and 314 nm.
  • the polymerizable mesogen compound (A) having one polymerizable functional group has, for example, the following general formula: (1)
  • the polymerizable mesogen compound (A) is not limited to these exemplified compounds.
  • Examples of the polymerizable chiral agent (B) include LC756 manufactured by BASF.
  • the compounding amount of the polymerizable chiral agent (B) is the same as that of the polymerizable mesogen compound (A).
  • the amount is preferably about 1 to 20 parts by weight, more preferably 3 to 7 parts by weight, based on the total of 100 parts by weight of the sex chiral agent (B).
  • the helical torsional force (HTP) is controlled by the ratio of the polymerizable mesogen compound (A) and the polymerizable chiral agent (B). By setting the ratio within the above range, the reflection band can be selected so that the reflection spectrum of the obtained cholesteric liquid crystal film can cover a long wavelength range.
  • the liquid crystal mixture usually contains a photopolymerization initiator (C).
  • a photopolymerization initiator C
  • Various photopolymerization initiators (C) can be used without particular limitation.
  • irgacure 184, irgacure 907, irgacure 369, and irgacure 651 manufactured by Chipa Specialty Chemicals Co., Ltd. may be mentioned.
  • the amount of the photopolymerization initiator is preferably about 0.01 to 10 parts by weight based on 100 parts by weight of the total of the polymerizable mesogen compound (A) and the polymerizable chiral agent (B). 0.05-5 parts by weight is more preferred.
  • the mixture can be mixed with an ultraviolet absorber to increase the difference in ultraviolet exposure intensity in the thickness direction.
  • an ultraviolet absorber having a large molar extinction coefficient.
  • the mixture can be used as a solution.
  • Solvents used for preparing the solution are usually chloroform, dichloromethane, dichloromethane, tetrachlorethane, trichloroethylene, tetrachloroethylene, and tetrachloroethylene.
  • Halogenated hydrocarbons such as benzene, phenols such as phenol and parachlorophenol, and aromatic hydrocarbons such as benzene, toluene, xylene, methoxybenzene and 1,2-dimethoxybenzene And others, such as acetone, methylethyl ketone, ethyl acetate, tert-butyl alcohol, glycerin, ethylene glycol, triethylene glycol, ethylene glycol, monomethylinoleate, diethyleneglycorereginette, Ethylsilenosolve, butyl cellosolve, 2-pyrrolidone, N-Methyl-1-2-pyrrolidone, pyridine, triethylamine, tetrahydrofuran, dimethylformamide, dimethylacetamide, dimethylsulfoxide, acetonitril, ptyronitrile, disulfide Carbon, cyclopentanone, cyclohex
  • the solvent used is not particularly limited, but methyl ethyl ketone, cyclohexanone, cyclopentanone, and the like are preferred.
  • the concentration of the solution cannot be determined unconditionally because it depends on the solubility of the thermopick liquid crystal compound and the final thickness of the target cholesteric liquid crystal film, but it is usually about 3 to 50% by weight. It is preferred that '
  • the production of the broadband cholesteric liquid crystal film of the present invention includes a step of applying the liquid crystal mixture to an alignment substrate, and a step of irradiating the liquid crystal mixture with ultraviolet rays and polymerizing and curing.
  • the alignment base material As the alignment base material, a conventionally known one can be used.
  • a polymer having a photo-crosslinking group such as a rubbing film, obliquely deposited film, or cinnamate diazobenzene, which is formed by forming a thin film made of polyimide or polyvinyl alcohol on a substrate and rubbing it with rayon cloth or the like
  • a light directing film or a stretched film obtained by irradiating a polyimide with polarized ultraviolet light is used.
  • orientation can be performed by magnetic field, electric field orientation, and shear stress operation.
  • the type of the base material is not particularly limited, but a material having a high transmittance is desirable in view of the method of irradiating irradiation light (ultraviolet rays) from the base material side.
  • the base material has a transmittance of at least 10%, preferably at least 2%, in the ultraviolet region of from 200 nm to 400 nm, more preferably from 300 nm to 400 nm. It is required to be 0% or more.
  • the plastic film has a transmittance of 10% or more, more preferably 20% or more, for ultraviolet light having a wavelength of 365 nm.
  • the transmittance is directly measured by U-410 Spectr ⁇ ⁇ hh ⁇ ⁇ ⁇ m te ter manufactured by HITACHI.
  • the substrate may be a plastic material such as polyethylene terephthalate, triacetyl cellulose, norbornene resin, polyvinyl alcohol, polyimide, polyarylate, polycarbonate, polysulfone or polyethersulfone.
  • a film or a glass plate is used.
  • Triacetyl cellulose manufactured by Fudo Photographic Film Co., Ltd., ARTON manufactured by JSR, and ZONEX manufactured by Zeon Corporation can be mentioned.
  • a polymer film described in Japanese Patent Application Laid-Open No. 2001-334529 for example, (A) Substituted or unsubstituted side chain
  • the resin composition include a thermoplastic resin having an imido group and (B) a thermoplastic resin having a substituted and / or unsubstituted fuunyl and a ditolyl group in a side chain.
  • Specific examples of such a film include a resin composition film containing an alternating copolymer of isoptylene and N-methylmaleimide and an acrylonitrile'styrene copolymer.
  • As the film a film made of a mixed extruded product of a resin composition or the like can be used.
  • the base material may be used while being bonded to the cholesteric liquid crystal layer, or may be peeled off. When using it as it is, use a material whose retardation value is sufficiently small for practical use.
  • the base material When the base material is used while being bonded, it is desirable that the base material does not decompose, deteriorate or yellow even when irradiated with ultraviolet rays.
  • the desired purpose can be achieved by adding a light stabilizer or the like to the above-mentioned base material.
  • the light stabilizer Tinuvin 120 and 144, manufactured by Chipa Specialty Chemicals, etc., are preferably used.
  • the wavelength from the exposure light to a wavelength of 300 nm or less, coloring, deterioration, and yellowing can be reduced.
  • the coating thickness of the liquid crystal mixture is preferably about 1 to 20 / ⁇ . If the coating thickness is thinner than 1 m, the reflection bandwidth can be secured, but the degree of polarization itself tends to decrease, which is not preferable.
  • the coating thickness is preferably 2 / Z1T1 or more, and more preferably 3 / 1m or more. On the other hand, when the coating thickness is larger than 20 / im, no remarkable improvement is seen in both the reflection bandwidth and the degree of polarization, and the cost is simply high, which is not preferable.
  • the coating thickness is preferably 15 m or less, more preferably 10 ⁇ or less.
  • the mixed solution for example, a roll coating method, a gravure coating method, a spin coating method, a bar coating method, or the like can be adopted.
  • the solvent is removed, and a liquid crystal layer is formed on the substrate.
  • the conditions for removing the solvent are not particularly limited, and it is sufficient that the solvent can be substantially removed, and the liquid crystal layer does not flow or drop.
  • the solvent is removed by drying at room temperature, drying in a drying oven, or heating on a hot plate.
  • the liquid crystal layer formed on the alignment base material is brought into a liquid crystal state, and cholesteric alignment is performed.
  • heat treatment is performed so that the liquid crystal layer has a liquid crystal temperature range.
  • the heat treatment can be performed by the same method as the above-mentioned drying method.
  • the heat treatment temperature varies depending on the type of liquid crystal material and alignment substrate, and cannot be unconditionally determined.
  • the heat treatment time varies depending on the heat treatment temperature and the type of liquid crystal material or alignment substrate used, but cannot be generally specified, but is usually in the range of 10 seconds to 2 hours, preferably in the range of 20 seconds to 30 minutes. Selected.
  • the step of applying to the alignment base material and irradiating the liquid crystal mixture with ultraviolet rays includes the above steps (1) to (4).
  • the step (1) in a state where the liquid crystal mixture is in contact with a gas containing oxygen, at a temperature of 20 ° C. or more, an ultraviolet irradiation intensity of 20 to 200 mW / cm 2 is used. UV irradiation from the alignment substrate side for ⁇ 5 seconds.
  • the liquid crystal mixture is polymerized to form a polymer oligomer having an average molecular weight of about 1,000 to 500,000, and the alignment base material side and its opposite side (the oxygen interface side) In the thickness direction, a difference in the reaction rate due to oxygen inhibition and a difference in the amount of generated radicals due to the absorption of ultraviolet light by the liquid crystal composition occur.
  • the temperature at the time of the first ultraviolet irradiation is set to 20 ° C. or higher in order to polymerize and cure the liquid crystal mixture in a favorable alignment state.
  • the upper limit of the temperature is not particularly limited, but is preferably 100 ° C. or lower. If the temperature is higher than 100 ° C
  • the temperature is preferably from 20 ° C to 50 ° C.
  • the first ultraviolet irradiation intensity is 2 0 ⁇ 2 0 0 mW / cm 2, preferably 2 5 ⁇ 2 0 0 mW / cm 2, 4 0 ⁇ : I 5 0 mWZ cm 2 Gayo more preferable. If the UV irradiation intensity is lower than 20 mW / cm 2 , polymerization will not be performed to the extent that a monomer distribution is formed in the thickness direction, so that the band will not be broadened. On the other hand, if the UV irradiation intensity is higher than 200 mW / cm 2 , the polymerization reaction rate becomes higher than the diffusion rate, so that the band cannot be broadened, which is not preferable.
  • the first ultraviolet irradiation time in the step (1) is 0.2 to 5 seconds, and preferably 0.3 to 3 seconds. More preferably, it is 0.5 to 1.5 seconds. If the time is shorter than 0.2 seconds, the polymerization is not carried out to such an extent that the monomer is distributed in the thickness direction, so that the band is not broadened. If the time is longer than 5 seconds, the change in the pitch of the cholesteric liquid crystal layer is not a continuous change from large to small from the alignment substrate side to the oxygen interface side, but is a discontinuous change. Discontinuous pitch changes cause severe coloring when viewed from an angle Become.
  • the exposure environment for ultraviolet irradiation is performed in a state where the liquid crystal mixture applied to the alignment base material is in contact with a gas containing oxygen.
  • the gas containing oxygen contains 0.5% or more of oxygen.
  • Such an environment may be any as long as oxygen polymerization inhibition can be used, and can be performed under a general atmospheric atmosphere.
  • the oxygen concentration may be increased or decreased in view of the wavelength width for controlling the pitch in the thickness direction and the speed required for polymerization.
  • the required amount of the photopolymerization initiator (C) tends to increase.
  • the polymerizable mesogen can be used.
  • the desired purpose can be achieved with an addition amount of about 1 to 5 parts by weight based on 100 parts by weight of the total of the compound (A) and the polymerizable chiral agent (B).
  • the polymer Z oligomer is formed in a weight-average molecular weight of about 1,000 to 5,000.
  • the weight average molecular weight of the polymer / oligomers is from 1000 to 3000.
  • the weight average molecular weight of the polymer oligomer is a value measured by the GPC method. The weight average molecular weight was calculated using polyethylene oxide as a standard sample.
  • Main unit Tosoh's HLC—8 120 GPC
  • Power Ram Tosoh's Super AWM- H + S Super AWM—H + Super AW 300 (0 mm each (i> X 15 c ni, total 45 cm), column temperature: 40 ° C, eluent: 10 mM—LiBr / NMP, flow rate: 0.4 ml_min, inlet pressure: 8.5 MPa, sample concentration : 0.1% NMP solution, Detector: Differential refractometer (RI).
  • the liquid crystal layer is heated at 70 to 120 ° C. for 2 seconds or more while being in contact with the gas containing oxygen.
  • the polymer / oligomer is formed with a concentration gradient in the thickness direction, so that the unpolymerized monomer component formed in the reverse direction remains in the thickness direction.
  • the concentration gradient distribution is made uniform in the thickness direction, and this is used to further increase the pitch length.
  • the heating temperature is preferably from 70 ° C to 100 ° C. If the temperature is lower than 70 ° C, the diffusion speed is very slow and it takes a long time to broaden the band. Also, it is not preferable because the orientation gradually deteriorates. On the other hand, if the temperature exceeds 120 ° C, the diffusion rate is too far to be controlled.
  • the heating time is at least 2 seconds, and further at least 10 seconds. However, since the liquid crystal layer supported on one side of the alignment substrate has an oxygen interface, if the heating time is prolonged, volatilization loss of liquid crystal composition components and photopolymerization initiator, deterioration of the film surface flatness, and adhesion of foreign matter Etc. tend to occur. Practically, the time is preferably 5 minutes or less, and more preferably 2 minutes or less.
  • the homogenization step by heating is performed for several seconds to several minutes, and it is not always necessary to perform heating in some places.
  • Japanese Patent No. 3,272,668 extending the selective reflection band of the cholesteric liquid crystal to more than twice that of a single pitch requires an annealing time of 4 minutes or more, and the visible light It took about 2 hours of annealing to create a selective reflection band of 300 nm or more covering the optical region.
  • the molecular weight of the reactant produced under the same reaction rate condition is low, Spreading speed is ensured.
  • the conditions for securing the diffusion rate have been greatly relaxed, and the pitch length has been sufficiently extended even in the short-time heating process in the light.
  • the speed of the production line is 10 m / min, patent specification No. 3,272,668 requires an annealing treatment at a place for as long as 120 minutes. Is a process that is virtually impossible inline.
  • the present invention can be implemented in a short time as described above, and there are few practical problems.
  • the liquid crystal layer is in contact with a gas containing oxygen, at a temperature of 20 ° C. or more, at a UV irradiation intensity lower than that of the step (1) for 10 seconds or more. Irradiate ultraviolet rays from the alignment substrate side.
  • the effective depth of polymerization inhibition by oxygen penetrating from the oxygen interface side can be made deeper than in step (1), and the pitch of the short pitch region on the oxygen interface side can be reduced.
  • the length is not substantially changed, and the reaction proceeds only in the long pitch region on the alignment substrate side, thereby further increasing the pitch on the alignment substrate side.
  • step (2) the remaining unreacted monomer is homogenized while maintaining the gradient structure of the polymer of the polymer / oligomer, that is, the structure of changing the pitch length, and then the second ultraviolet irradiation in step (3) is performed.
  • the residual monomer is polymerized, and a pitch gradient is formed.
  • the effective depth of polymerization inhibition due to oxygen penetrating from the oxygen interface side can be made deeper than in step (1), and the pitch length of the short pitch region on the oxygen interface side does not substantially change.
  • step (1) Since the increase in the molecular weight and the decrease in the diffusion rate of the liquid crystal composition layer are significantly different from those during the first ultraviolet irradiation in step (1), the amount of radicals generated per unit time is reduced, and the progress rate of polymerization is reduced. This allows for a wider bandwidth.
  • the temperature at the time of the irradiation of the second ultraviolet ray is 20 ° C. or more.
  • the upper limit of the temperature is not particularly limited, but is preferably 140 ° C. or lower. More preferably, the temperature is from 60 ° C to 140 ° C, more preferably from 80 ° C to 120 ° C. If the temperature is lower than 20 ° C, the diffusion rate of the polymerizable mesogen compound (a) is extremely slow, and it takes a long time to broaden the band. It will take some time.
  • Irradiation is performed at a second UV irradiation intensity lower than the first UV irradiation intensity.
  • the second UV irradiation intensity is preferably 1 to 50 mW / c in 2 in a range lower than the first UV irradiation intensity.
  • the second ultraviolet irradiation time depends on the illuminance, but is generally preferably 10 seconds or more, and more preferably 30 seconds or more.
  • the ultraviolet irradiation time is preferably not more than 120 seconds, more preferably not more than 60 seconds from the viewpoint of working time.
  • Patent Document 3 272 668 requires a long annealing time, which has a serious problem in practical use.
  • the process (3) has a defect such as a discontinuous change in the pitch length in the process (1), it can be made continuous. If the change in pitch length is discontinuous, only specific wavelengths will be cut or the transmittance will be high, resulting in unnecessary characteristics in the selective reflection wavelength band. In such a case, problems such as uneven color tone in the plane or uneven coloring of the color tone occur. Furthermore, as described above, the wavelength characteristic shifts to a short wavelength at oblique incidence, so that when the emission line spectrum of the light source is applied to the extraordinary wavelength region where the transmittance is high or low, the sharp color tone * brightness This will cause a change and significantly degrade the visibility.
  • step (3) Since the band broadening process in step (3) is different from the band broadening in step (1) under the condition of ultraviolet irradiation, even if a discontinuity in pitch length change occurs, it differs from the wavelength range formed in step (1). Since they occur in the area, the superposition effect as a whole complements each other's shortcomings, resulting in a continuous change.
  • This step (3) If not, for example, in the case of Example 2 of Japanese Patent Application Laid-Open No. 2002-286935, a step occurs in the extended band, but in the present invention, As shown in the figure, it has continuous and smooth characteristics. This is very advantageous in actual use.
  • step (3) the broadening of the band by the step (3) enables the broadening of the band as described in the later-described embodiment, and coloring and color omission by oblique incident light due to blue shift occur.
  • the viewing angle becomes extremely large, and coloring due to the viewing angle can be significantly reduced.
  • step (4) ultraviolet irradiation is performed in the absence of oxygen.
  • the third ultraviolet ray irradiation the cholesteric reflection band extended in steps (1) to (3) is cured without deteriorating. As a result, the pitch change structure is fixed without deterioration.
  • the absence of oxygen can be, for example, an inert gas atmosphere.
  • the inert gas is not particularly limited as long as it does not affect the ultraviolet polymerization of the liquid crystal mixture.
  • examples of such an inert gas include nitrogen, argon, helium, neon, xenon, and krypton. Of these, nitrogen is the most versatile and preferred. Further, by bonding a transparent base material to the cholesteric liquid crystal layer, it is possible to eliminate the presence of oxygen.
  • the ultraviolet irradiation may be performed from either the alignment substrate side or the applied liquid crystal mixture side.
  • the ultraviolet irradiation condition is not particularly limited as long as the liquid crystal mixture is cured. Usually, it is preferable to irradiate at an irradiation intensity of about 40 to 300 mWZ cm 2 for about 1 to 60 seconds.
  • the irradiation temperature is about 20 to 100 ° C.
  • the crosslink density of the liquid crystal layer is improved.
  • the reliability is significantly improved due to the increase in the molecular weight.
  • ultraviolet irradiation is performed from the alignment substrate surface side in order to positively utilize oxygen inhibition in the first ultraviolet irradiation in the step (1) and the second ultraviolet irradiation in the step (3). For this reason, it is possible to form a large gradient in the reaction rate in the thickness direction, but the problem is that the polymerization rate on the air interface side is low, and the hardness and strength of the film surface are insufficient, or long-term reliability is a problem. There is a possibility that problems such as lack of sex may occur.
  • step (4) third ultraviolet irradiation is performed in an oxygen-free atmosphere to complete polymerization of the remaining monomer, Enhancing film quality.
  • the reaction rate of the surface does not improve sufficiently in an air atmosphere (in the presence of oxygen), and it is difficult for the reaction rate to exceed 90%. Therefore, in order to obtain sufficient reliability, it is desired to perform ultraviolet irradiation in the absence of oxygen.
  • the direction of the irradiation surface is not particularly limited.
  • Irradiation from the liquid crystal layer side is desirable, but the reaction on the surface proceeds sufficiently even under irradiation from the substrate side under a nitrogen atmosphere.
  • the cholesteric liquid crystal film obtained in this way peels off from the substrate It may be used without being used, or may be peeled off from the substrate.
  • the broadband cholesteric liquid crystal film of the present invention is used as a circularly polarizing plate.
  • a linear polarizing element can be obtained by laminating a ⁇ / 4 plate on the circularly polarizing plate. It is preferable that the cholesteric liquid crystal film, which is a circularly polarizing plate, is laminated on the ⁇ / 4 plate so that the pitch length is continuously narrowed.
  • a / 4 plate is not particularly limited, but a phase difference is generated by stretching such as polycarbonate, polyethylene terephthalate, polystyrene, polysnoreon, polyvinyl alcohol, polymethyl methacrylate, etc.
  • General-purpose transparent resin film Norbornene resin film such as ARTON film manufactured by JSR is suitably used.
  • a quarter plate obtained by fixing liquid crystal by fixing a quarter layer may be used. In this case, the thickness of the 4 plate can be significantly reduced.
  • the thickness of the ⁇ 4 wave plate is usually preferably from 0.5 to 200 / im, especially: It is preferably up to 100 ⁇ m.
  • a retardation plate that functions as a ⁇ / 4 wavelength plate in a wide wavelength range such as a visible light castle is, for example, a retardation layer that functions as a / 4 wavelength plate for light-colored light having a wavelength of 550 nm. It can be obtained by a method in which a phase difference layer exhibiting other phase difference characteristics, for example, a phase difference layer functioning as a two-wavelength plate is superimposed. Therefore, the retardation plate disposed between the polarizing plate and the brightness enhancement film may be composed of one or two or more retardation layers. Paste along the transmission axis direction Used together.
  • the polarizer is not particularly limited, and various types can be used.
  • polarizers include iodine and two-color polarizers, such as hydrophilic polymer films such as polyvinyl alcohol-based films, partially formalized polyvinyl alcohol-based films, and polyethylene / butyl acetate copolymer-based partially saponified films. Uniaxially stretched by adsorbing a dichroic substance such as a chromatic dye; a dehydrated product of polyvinyl alcohol; a dehydrochlorination product of polyvinyl chloride; and a polyene-based oriented film.
  • a polarizer made of a polyvinyl alcohol-based film and a dichroic substance such as iodine is preferable.
  • the thickness of these polarizers is not particularly limited, but is generally about 5 to 80 ⁇ .
  • a polarizer obtained by dyeing a polyvinyl alcohol-based film with iodine and uniaxially stretching is dyed, for example, by immersing polyvinyl alcohol in an aqueous solution of iodine, and stretching it to 3 to 7 times its original length. Can be made. If necessary, it can be immersed in an aqueous solution of boric acid or potassium iodide. If necessary, the polyvinyl alcohol-based film may be immersed in water and washed with water before dyeing. Polyvinyl alcohol-based film is obtained by washing the polyvinyl alcohol-based film with water.
  • Stretching may be performed after dyeing with iodine, may be performed while dyeing, or may be dyed with iodine after stretching.
  • the film can be stretched in an aqueous solution of boric acid or calcium iodide or in a water bath.
  • the polarizer is usually provided with a transparent protective film on one or both sides and used as a polarizing plate. It is preferable that the transparent protective film is excellent in transparency, mechanical strength, heat stability, moisture shielding property, isotropy and the like.
  • Transparent protective films include, for example, polyester polymers such as polyethylene terephthalate and polyethylene naphthalate, senorellose polymers such as diacetinose / relose, triacetinoresenorelose, etc., and polymers. Examples include films made of transparent polymers such as acrylic polymers such as carbonate polymers and polymethylmethacrylate.
  • Styrene polymers such as polystyrene, acrylonitrile and styrene copolymer, polyethylene, polypropylene, polyolefin having cyclic or norbornene structure, and ethylene.
  • 'Films made of transparent polymers such as olefin-based polymers such as propylene copolymers, vinyl chloride-based polymers, and amide-based polymers such as vinyl-aromatic polyamides can also be used.
  • imid polymer sulfone polymer, polyether sulfone polymer, polyether ether ketone polymer, polyphenylene sulfide polymer, vinyl alcohol polymer, vinylidene chloride polymer, BULL
  • a film made of a transparent polymer such as a butyral-based polymer, an arylate-based polymer, a polyoxymethylene-based polymer, an epoxy-based polymer, or a blend of the above polymers is also included.
  • those having low optical birefringence are preferably used.
  • triacetyl cellulose, polycarbonate, acrylic polymer, cycloolefin resin, polyolefin having a norbornene structure, and the like are preferable.
  • a polymer film described in Japanese Patent Application Laid-Open Publication No. 2001-334529 for example, (A) substituted or unsubstituted And (B) a thermoplastic resin having a substituted and / or unsubstituted phenyl in the side chain and a thermoplastic resin having a ditolyl group.
  • a film of a resin composition containing an alternating copolymer of isobutylene and N-methylmaleide and an acrylonitrile / styrene copolymer As the film, a film composed of a mixed extruded product of a resin composition or the like can be used.
  • a transparent substrate that can be particularly preferably used in view of polarization characteristics and durability is a triacetyl cellulose film whose surface is saponified with alkali or the like.
  • the thickness of the transparent protective film can be determined as appropriate, but is generally about 10 to 500 / x m from the viewpoint of workability such as strength and handleability and thinness. In particular, it is preferably from 20 to 300 m, more preferably from 30 to 200 ⁇ .
  • a protective film having a retardation value in the thickness direction of the film represented by) of _90 nm to +75 nm is preferably used.
  • the polarizing plate caused by the protective film can be used. Coloring (optical coloring) can be almost completely eliminated.
  • the thickness direction retardation value (R th) is more preferably 180 nm + 60 nm, particularly preferably 170 nm + 45 nm.
  • a transparent protective film made of the same polymer material on both sides may be used, or a transparent protective film made of a different polymer material or the like may be used.
  • the surface of the transparent protective film on which the polarizer is not adhered may be subjected to a hard coat layer, an antireflection treatment, a treatment for preventing sticking, and a treatment for diffusion or antiglare.
  • the coating treatment is performed for the purpose of preventing scratches on the surface of the polarizing plate.
  • a cured film having an excellent hardness and a sliding property by a suitable ultraviolet curable resin such as an acrylic or silicone resin is used. It can be formed by a method of adding to the surface of the protective film.
  • the anti-reflection treatment is performed for the purpose of preventing reflection of external light on the polarizing plate surface, and can be achieved by forming an anti-reflection film or the like according to the related art.
  • the anti-stating treatment is performed to prevent adhesion to the adjacent layer.
  • the anti-glare treatment is performed to prevent external light from being reflected on the surface of the polarizing plate and hindering the visibility of light transmitted through the polarizing plate.
  • the surface of the transparent protective film is provided with a fine uneven structure by an appropriate method such as a sandblasting method, a roughening method using an embossing method, or a compounding method of transparent fine particles.
  • an appropriate method such as a sandblasting method, a roughening method using an embossing method, or a compounding method of transparent fine particles.
  • the fine particles to be included in the formation of the surface fine unevenness include silica having an average particle diameter of 0 to 550 ⁇ , alumina, titania, zirconia, tin oxide, indium oxide, and oxidizing power.
  • Transparent fine particles such as conductive inorganic fine particles made of antimony oxide or the like, and organic fine particles made of a crosslinked or uncrosslinked polymer or the like are used.
  • the amount of fine particles used is generally about 250 parts by weight with respect to 100 parts by weight of the transparent resin forming the fine surface unevenness structure, and Parts are preferred.
  • the anti-glare layer may also serve as a diffusion layer (such as a viewing angle expanding function) for diffusing light transmitted through the polarizing plate to increase the viewing angle and the like.
  • the anti-reflection layer, anti-sticking layer, diffusion layer, anti-glare layer and the like can be provided on the transparent protective film itself, or separately provided as an optical layer separately from the transparent protective layer. You can also.
  • the above-mentioned linear polarizing element may be provided with an adhesive layer for bonding to another member such as a liquid crystal cell.
  • the pressure-sensitive adhesive that forms the pressure-sensitive adhesive layer is not particularly limited, but is, for example, based on polymers such as acrylic polymers, silicone polymers, polyesters, polyurethanes, polyamides, polyethers, and fluorine and rubber polymers.
  • a polymer can be appropriately selected and used.
  • those having excellent optical transparency such as an acrylic adhesive, exhibiting appropriate wettability, cohesiveness and adhesive adhesive properties, and having excellent weather resistance and heat resistance are preferably used.
  • an adhesive layer with low moisture absorption and excellent heat resistance is preferred.
  • the adhesive layer is made of, for example, a natural or synthetic resin, particularly a tackifying resin, a filler, a pigment, a colorant, an antioxidant, and the like made of glass fiber, glass beads, metal powder, and other inorganic powders. May be added to the pressure-sensitive adhesive layer.
  • a natural or synthetic resin particularly a tackifying resin, a filler, a pigment, a colorant, an antioxidant, and the like made of glass fiber, glass beads, metal powder, and other inorganic powders. May be added to the pressure-sensitive adhesive layer.
  • an adhesive layer containing fine particles and exhibiting light diffusibility may be used.
  • the attachment of the adhesive layer may be performed by an appropriate method. For example, about 10 to 40% by weight of an adhesive obtained by dissolving or dispersing a base polymer or a composition thereof in a solvent composed of a single solvent or a mixture of appropriate solvents such as toluene and ethyl acetate.
  • An adhesive solution is prepared and applied directly on the polarizer by an appropriate developing method such as a casting method or a coating method, or an adhesive layer is formed on a separator according to the method described above, and then the optical element is formed. There is a method to transfer to the top.
  • the adhesive layer may be provided as a superimposed layer of different compositions or types of layers.
  • the thickness of the pressure-sensitive adhesive layer can be appropriately determined depending on the purpose of use, adhesive strength, and the like, and is generally 1 to 500 / m, preferably 5 to 200 ⁇ m, and more preferably 10 to 1 / m. 0 ⁇ ⁇ ⁇ is preferred.
  • a separator is temporarily attached to the exposed surface of the adhesive layer to prevent contamination, etc., until it is practically used, and is covered. This allows the adhesive layer to be used in normal handling conditions. Contact can be prevented.
  • the separator may be any suitable thin leaf such as a plastic film, rubber sheet, paper, cloth, non-woven fabric, net, foamed sheet or metal foil, or a laminate thereof. If necessary, use an appropriate material similar to the conventional one, such as one coated with an appropriate release agent such as a silicone-based, long-chain alkyl-based, fluorine-based, or molybdenum sulfide.
  • Each layer such as the adhesive layer is treated with an ultraviolet absorber such as a salicylate compound, a benzofurnol compound, a benzotriazole compound, a cyanoacrylate compound, or a nickel complex compound.
  • an ultraviolet absorber such as a salicylate compound, a benzofurnol compound, a benzotriazole compound, a cyanoacrylate compound, or a nickel complex compound.
  • a material having an ultraviolet ray absorbing ability according to such a method may be used.
  • the linear polarizing element of the present invention can be preferably used for forming various devices such as a liquid crystal display device.
  • the formation of the liquid crystal display device can be performed according to a conventional method. That is, a liquid crystal display device is generally formed by appropriately assembling components such as a liquid crystal cell, an optical element, and, if necessary, an illumination system and incorporating a drive circuit. There is no particular limitation except that a polarizing element is used, and the conventional method is used.
  • the liquid crystal cell any type such as TN type, STN type, and ⁇ type may be used.
  • An appropriate liquid crystal display device such as a liquid crystal display device in which the linear polarizing element is arranged on one side or both sides of a liquid crystal cell, or a lighting system using a backlight or a reflector can be formed.
  • the linear polarizing element according to the present invention can be installed on one side or both sides of the liquid crystal cell.
  • linear polarizing elements are provided on both sides, they may be the same or different.
  • appropriate components such as a diffusion plate, an anti-glare layer, an anti-reflection film, a protection plate, a prism array, a lens array sheet, a light diffusion plate, and a backlight are appropriately positioned.
  • One layer or two or more layers can be arranged in one layer.
  • the circular polarizer (reflective polarizer) using the cholesteric liquid crystal film is provided between at least two reflective polarizers (a) in which the wavelength bands of selective reflection of polarized light overlap each other.
  • a retardation layer (b) having a front phase difference (normal direction) of almost zero and having a phase difference of / 8 or more with respect to incident light incident at an angle of 30 ° or more with respect to the normal direction is arranged.
  • the cholesteric liquid crystal film is Either the maximum pitch or the minimum pitch of the helical twisted molecular structure may be the side of the retardation layer (b), but from the viewpoint (the viewing angle is good, the coloring is small), the reflection polarizer (a) is used.
  • the polarizing element system that is, the cholesteric liquid crystal laminate having a wide-band selective reflection function has a circularly-polarized reflection / transmission function in the front direction, and is used in a liquid crystal display device as a wide-band circularly polarizing plate.
  • a liquid crystal display device as a wide-band circularly polarizing plate.
  • it can be used as a circularly polarizing plate by disposing it on the light source side of a circularly polarized mode liquid crystal cell, for example, a transmissive VA mode liquid crystal cell having multiple domains.
  • the phase difference layer (b) has a phase difference of almost zero in the front direction and has a phase difference of ⁇ / 8 or more with respect to incident light at an angle of 30 ° from the normal direction.
  • the front phase difference is desirably LZ10 or less because the purpose is to maintain the vertically polarized light.
  • the incident light from the oblique direction is appropriately determined by the angle of total reflection so as to be efficiently converted in polarization. For example, 60 to completely reflect at an angle of about 60 ° from the normal. What is necessary is just to determine so that the phase difference when measured at is about ⁇ / 2.
  • the transmitted light by the reflective polarizer (a) changes its polarization state due to the C-plate birefringence of the reflective polarizer itself, it is measured at that angle of the normally inserted C-plate.
  • the phase difference at this time can be a value smaller than 1/2. Since the phase difference of the C-plate increases monotonically as the incident light is inclined, the effective total reflection occurs when the angle of inclination is 30 ° or more. And L / 8 or more.
  • the material of the retardation layer (b) is not particularly limited as long as it has the above-mentioned optical characteristics.
  • Columnar orientation of discotic liquid crystal, nematic orientation, negative uniaxial crystal in-plane orientation examples include biaxially oriented polymer films.
  • the C plate in which the cholesteric liquid crystal having a selective reflection wavelength other than the visible light region (380 nm to 780 nm) has a fixed planar state is a selective reflection wavelength of the cholesteric liquid crystal. It is desirable that the visible light region has no coloring or the like. Therefore, it is necessary that the selective reflection light is not in the visible region.
  • the selective reflection is uniquely determined by the chiral pitch of the cholesteric and the refractive index of the liquid crystal.
  • the value of the central wavelength of selective reflection may be in the near-infrared region, but it may be in the ultraviolet region of 35 O nm or less because it is affected by optical rotation and causes a somewhat complicated phenomenon. More desirable.
  • the formation of the cholesteric liquid crystal layer is performed in the same manner as the formation of the cholesteric layer in the reflective polarizer described above.
  • the C-plate having a fixed homeotropic orbital alignment state is a liquid crystalline thermoplastic resin or a liquid crystal monomer exhibiting nematic liquid crystallinity at a high temperature, and an alignment aid as required, and ionizing radiation such as an electron beam or ultraviolet light.
  • Polymerizable liquid crystal polymerized by irradiation or heat, or a mixture thereof is used.
  • the liquid crystal properties may be either lyotropic or thermotropic, but from the viewpoint of easy control and easy formation of a monodomain, it is desirable that the liquid crystal be a thermostatically-picking liquid crystal.
  • the homeotropic alignment can be obtained, for example, by applying the above-mentioned birefringent material on a film on which a vertical alignment film (such as long-chain alkylsilane) is formed, and developing and fixing a liquid crystal state.
  • a C-plate using a discotic liquid crystal as a liquid crystal material, a negative uniaxial compound such as a phthalocyanine compound or a triphenylene compound having an in-plane molecular spread is used. It is a discotic liquid crystal material that has properties and is fixed by developing a nematic phase and a columnar phase. Negative uniaxial inorganic layered compounds are described in detail in, for example, Japanese Patent Application Laid-Open Publication No. Hei 6—8277777.
  • C-plates using biaxial orientation of polymer film are a method of biaxially stretching a polymer film having positive refractive index anisotropy, a method of pressing a thermoplastic resin, and a crystal in parallel orientation. It can be obtained by the method of cutting out from the.
  • the layers may be stacked only, but it is preferable that the layers be stacked using an adhesive or a pressure-sensitive adhesive from the viewpoint of workability and light use efficiency.
  • the adhesive or adhesive is transparent, has no absorption in the visible light range, and the refractive index is as high as the refractive index of each layer. Closer to each other is desirable from the viewpoint of suppressing surface reflection. From this viewpoint, for example, an acrylic adhesive is preferably used.
  • a monodomain is separately formed in the form of an alignment film and then sequentially laminated by a method such as transfer to a translucent grave material, or an alignment film is provided for alignment without providing an adhesive layer. It is also possible to form such layers appropriately and to directly form each layer sequentially.
  • Particles may be added to each layer and the (viscosity) adhesive layer to adjust the degree of diffusion, if necessary, to provide isotropic scattering, or to use an ultraviolet absorber, an antioxidant, A surfactant or the like can be appropriately added for the purpose of imparting leveling properties.
  • the polarizing element (cholesteric liquid crystal laminate) of the present invention has a function of reflecting / transmitting circularly polarized light, it can be used as a linearly polarizing element that converts transmitted light into linearly polarized light by combining four plates. Can be. Examples of the ⁇ / 4 plate include the same as those described above.
  • a / 4 plate has a single layer made of a single material that works well only for a specific wavelength, but there is a problem that the function of the / 4 plate is reduced for other wavelengths due to wavelength dispersion characteristics . Therefore, by laminating the ⁇ 2 plate with the specified axis angle, the ⁇ 2 plate can be used as a broadband / 4 plate that functions within a practically acceptable range over the entire visible light range.
  • each of the four plates and the two ⁇ plates may be made of the same material, or a combination of materials manufactured using different materials obtained by the same method as the ⁇ plate described above may be used.
  • a quarter-wave plate 140 nm
  • a ⁇ 2 plate 270 nm
  • the transmission polarization axis is 10 degrees with respect to the axis of the ⁇ / plate. Since the bonding angle varies depending on the phase difference value of each phase difference plate, the bonding angle is not limited to the above bonding angle.
  • An absorptive polarizer is attached to the transmission axis of the linearly polarizing element so that its transmission axis direction is aligned.
  • a diffuse reflection plate below the light guide plate as the light source (on the side opposite to the liquid crystal cell arrangement surface).
  • the main component of the light beam reflected by the collimating film is an oblique incident component, which is specularly reflected by the collimating film and returned to the backlight direction.
  • the back side reflector has high specularity, the reflection angle is preserved, and Light is lost due to scratches. Therefore, it is desirable to dispose a diffuse reflector in order to increase the diffuse reflection component in the front direction without preserving the reflection angle of the reflected return light beam.
  • the diffusion plate used can be obtained by embedding fine particles having different refractive indices in a resin, etc., in addition to the one having the uneven surface shape.
  • This diffusion plate may be sandwiched between the collimating film and the pack light, or may be bonded to the collimating film.
  • a U-ton ring may occur in the gap between the film surface and the backlight.
  • a diffusion plate having surface irregularities on the light plate side surface the generation of Newton rings can be suppressed.
  • a layer having both the concavo-convex structure and the light diffusion structure may be formed on the surface of the parallel light conversion film in the present invention.
  • the viewing angle expansion in the liquid crystal display device of the present invention is achieved by diffusing the light beams having good display characteristics near the front obtained from the liquid crystal display device combined with the parallelized backlight, so as to be uniform within the entire viewing angle. It is obtained by obtaining good display characteristics.
  • a diffusion plate having substantially no back scattering is used as the viewing angle widening film used here.
  • the diffusion plate can be provided as a diffusion adhesive.
  • the placement location is on the viewing side of the liquid crystal display device, but it can be used either above or below the polarizing plate.
  • a film that does not substantially eliminate polarized light is desirable.
  • a fine particle-dispersed diffusion plate as disclosed in Japanese Patent Application Laid-Open No. 2000-347706 and Japanese Patent Application Laid-Open No. 2000-34707 is preferably used.
  • the viewing angle widening film When the viewing angle widening film is located outside the polarizing plate, the liquid crystal layer and the polarizing plate In the case of a TN liquid crystal cell, it is not particularly necessary to use a viewing angle compensating phase difference plate because the collimated light beam is transmitted. In the case of an STN liquid crystal cell, it is only necessary to use a retardation film in which only the front characteristics are well compensated. In this case, since the viewing angle widening film has an air surface, it is possible to adopt a type using a refraction effect due to the surface shape. When a viewing angle-enhancing film is inserted between the polarizing plate and the liquid crystal layer on the negative side, the light is diffused when the film passes through the polarizing plate.
  • the viewing angle characteristics of the polarizer itself must be compensated. In this case, it is necessary to insert a retardation plate for compensating the viewing angle characteristics of the polarizer between the polarizer and the viewing angle widening film. In the case of STN liquid crystal, it is necessary to introduce a retardation plate that compensates for the viewing angle characteristics of the polarizer in addition to the front phase difference compensation of the STN liquid crystal.
  • the regular structure is not visually recognized in the plane, and there is no regular modulation in the emitted light. Therefore, it is not necessary to consider the compatibility with the viewing angle expansion film and the arrangement order. Therefore, the viewing angle widening film is not particularly limited as long as it does not cause interference / moire with the pixel black matrix of the liquid crystal display device, and there are a wide range of options.
  • the viewing angle widening film has substantially no backscattering and does not eliminate polarization, and is disclosed in Japanese Patent Application Laid-Open Publication No. 2000-34067 and Japanese Patent Publication No.
  • it even if it has a regular structure inside, such as a hologram sheet, microprism array, microphone opening lens array, etc., it can be used without forming interference / moire with the pixel black matrix of the liquid crystal display device.
  • liquid crystal display device is manufactured by appropriately using various optical layers and the like according to an ordinary method.
  • Photopolymerizable mesogen compound (polymerizable nematic liquid crystal monomer, compound 20 in Table 1 above, molar extinction coefficient is 1 dm 3 mo 1 _1 cm “ 1 ® 365 nm, 2 100 dm 3 mo 1 _1 cm “1 ® 3 3 4 nm, 3 6 0 0 0 dm 3 mol one 1 c m- ⁇ S lnm purity> 99% of was used.)
  • 9 4.8 parts by weight of a polymerizable chiral agent BASF LC750
  • a solvent cyclohexanone
  • a coating solution (solid content: 30% by weight) was prepared by adding 3% by weight of a polymerization initiator (Irgacure 907, manufactured by Chipa Specialty Chemicals).
  • the coating solution is applied on a stretched polyethylene terephthalate film (oriented substrate) using a wire bar so that the thickness after drying becomes 6 ⁇ m, and the solvent is applied at 100 ° C. Dry for 2 minutes.
  • the obtained film was irradiated with a first ultraviolet ray at 50 mW / cm 2 for 1 second in an air atmosphere at 40 ° C. from the alignment substrate side. Thereafter, heating was performed at 90 ° C for 1 minute without irradiation with ultraviolet rays (the selective reflection wavelength band at this time was 420 to 650 nm).
  • a negative biaxial retardation plate was transferred onto the upper part of the obtained broadband cholesteric liquid crystal film (circularly polarizing reflector).
  • This negative biaxial retardation plate was obtained by the following method. That is, the concentration is 30% by weight in 93 parts by weight of the photopolymerizable nematic liquid crystal monomer (BASF, LC224) and 7 parts by weight of the polymerizable chiral agent (BASF, LC756).
  • BASF, LC224 photopolymerizable nematic liquid crystal monomer
  • BASF, LC756 the polymerizable chiral agent
  • irgacure 907 is used as a photopolymerization initiator for the solid content described above.
  • a circularly-polarized light reflecting plate similar to that described above was transferred onto the upper portion using the same translucent adhesive to form a ridge layer, thereby obtaining a solid optical device.
  • a linear polarizing element was obtained by adhering a Peno 4 plate (front retardation: 140 II m) obtained by uniaxially stretching the polycarbonate film to the obtained optical element.
  • Example 1 a polarizing element; a linear polarizing element obtained by laminating an I-no. 4 plate, and a: ⁇ / 2 plate obtained by uniaxially stretching a polycarbonate film on the A front phase difference of 270 nm) was adhered to obtain a straight line ⁇ ko Hatako.
  • a polarizing plate (TEG1465DU, manufactured by Nitto Dye Co., Ltd.) was bonded to the linear polarizing element so that the transmission axis directions were aligned, to obtain a polarizing plate integrated polarizing element.
  • the angle between the stretching axis (slow axis) of the ⁇ 4 plate and the ⁇ / 2 plate and the stretching axis (absorption axis) of the polarizing plate was set as shown in FIG.
  • PL indicates an absorption-type polarizing plate
  • (1 indicates a No. 4 plate (front phase difference I 40 nni)
  • C2 indicates a ⁇ / 2 plate (front phase difference 2700 nm).
  • the mark indicates the stretching axis (long side direction), where 01 is 17.5 and 02 is 80.
  • Example 1 A polycarbonate film was biaxially stretched on the photon obtained in Example 1; a four plate (front retardation: 125 nm, Nz coefficient: 11.0) was adhered. A linear polarization cord was obtained. A polarizing plate (Nitto Denko Corporation, TEG 1 4 6 5 (DU) were bonded together so that the transmission axis directions coincided to obtain a polarizing element integrated with a polarizing plate.
  • a coating solution containing the liquid crystal mixture prepared in Example 1 was applied on a stretched polyethylene terephthalate film (alignment substrate) using a wire bar so that the thickness after drying was 6 ⁇ m.
  • the solvent was dried at 1000C for 2 minutes.
  • the obtained film was irradiated with ultraviolet rays at 50 mW / cm 2 for 10 seconds in an air atmosphere at 40 ° C. from the orientation substrate side. At this time, the selective reflection wavelength band was approximately 420 to 800 nm.
  • Fig. 4 shows the reflection spectrum of the broadband cholesteric liquid crystal film.
  • a negative biaxial retardation similar to that of Example 1 was applied to the upper part of the obtained broadband cholesteric liquid crystal film (circularly-polarized light reflecting plate) using a translucent adhesive. The board was transferred.
  • a circularly-polarized light reflecting plate similar to that described above was transferred and laminated on the upper portion using the same translucent adhesive to obtain a polarizing element.
  • a linear polarizing element was obtained by adhering a four-layer plate (front retardation: 140 nm) obtained by uniaxially stretching the polycarbonate film to the obtained polarizing element.
  • a coating liquid containing the liquid crystal mixture prepared in Example 1 was applied on a stretched polyethylene terephthalate film (alignment substrate) using a wire par so as to have a thickness after drying of 6 ⁇ m.
  • the solvent was dried at 1000C for 2 minutes.
  • the obtained film was irradiated with ultraviolet rays at 50 mW / cm 2 for 1 second in an air atmosphere at 40 ° C. from the orientation substrate side. Thereafter, heating was performed at 90 ° C for 1 minute without irradiation with ultraviolet rays (the selective reflection wavelength band at this time was 420 to 650 nm).
  • Example 2 In the same manner as in Example 1, a negative biaxial retardation similar to that of Example 1 was applied to the upper part of the obtained broadband cholesteric liquid crystal film (circularly-polarized light reflecting plate) using a translucent adhesive. The board was transferred.
  • a circularly polarized light reflecting plate similar to that described above was transferred and laminated on the upper portion using the same light-transmitting adhesive to obtain a polarizing element.
  • a polycarbonate film was uniaxially stretched to the obtained polarizing element.
  • An YZ4 plate (front retardation: 140 nm) was adhered to obtain a linear polarizing element.
  • a polarizing plate (TEG1465DU, manufactured by Nitto Denko Corporation) was adhered to the linear polarizing element so that the transmission axis directions coincided with each other to obtain a polarizing plate integrated polarizing element.
  • the coating liquid containing the liquid crystal mixture prepared in Example 1 was applied on a stretched polyethylene terephthalate film (alignment substrate) using a wire bar so that the thickness after drying was 6 m, and the solvent was applied.
  • the obtained film was irradiated with ultraviolet rays at 50 mW / cm 2 for 1 second in an air atmosphere at 40 ° C. from the orientation substrate side. Thereafter, heating was performed at 90 ° C for 1 minute without irradiation with ultraviolet light (the selective reflection wavelength band at this time was 420 to 650 nm).
  • Example 2 The same negative biaxial phase as in Example 1 was applied to the top of the obtained broadband cholesteric liquid crystal film (circularly polarized light reflecting plate) in the same manner as in Example 1 using a translucent adhesive. The difference plate was transferred.
  • a circularly polarized light reflecting plate similar to the above was transferred and laminated on the upper portion using the same translucent adhesive to obtain a polarizing element.
  • a polycarbonate film was uniaxially stretched to the obtained polarizing element; a LZ 4 plate (front retardation: 140 nm) was bonded to obtain a linear polarizing element.
  • a polarizing plate (manufactured by Nitto Denko Corporation, TEG1465DU) was attached to the linear polarizing element so that the transmission axis directions were aligned, to obtain a polarizing element integrated with the polarizing plate. (Liquid crystal display)
  • the polarizing plate integrated with the polarizing plate obtained in each example was used as the lower plate of the TFT-LCD, while an acrylic adhesive (thickness 25 / zm, refractive index 1.47) was used on the upper plate side.
  • 20 weight spherical silica particles (refractive index: 1.44, diameter: 4 / m).
  • a polarizing plate (TEG1465 DU, manufactured by Nitto Denko Corporation) was laminated using a light-scattering adhesive (haze 80%) embedded in / 0 .
  • a cold cathode tube with a diameter of about 3 mm was placed on the side of a light guide having a fine prism structure on the lower surface, and covered with a light source holder made of silver-deposited polyethylene terephthalate film.
  • a silver-evaporated polyethylene terephthalate film reflector was arranged on the lower surface of the light guide plate, and a polyethylene terephthalate film having a scattering layer made of styrene beads formed on the surface was arranged on the upper surface of the light guide plate. This was disposed as a light source below the polarizing plate integrated with the polarizing element.
  • FIG. 1 shows a case in which the polarizing plate integrated type polarizing elements of Examples 1 and 3 and Comparative Examples 1 to 3 are used
  • FIG. 2 shows a case in which the polarizing plate integrated type polarizing element of Example 2 is used.
  • PL is an absorption polarizer
  • D is a viewing angle widening film (diffusion adhesive)
  • LC is a liquid crystal cell
  • C 1 is a ⁇ / 4 plate
  • C 2 is a ⁇ '2 plate
  • ⁇ is Reflective polarizer
  • B is retarder
  • S is thyroid type light guide plate
  • R indicates a diffuse reflection plate.
  • X indicates a polarization element
  • Y indicates a linear polarization element
  • Z indicates a polarization-integrated linear polarization element.
  • the broadband cholesteric liquid crystal film (circularly polarizing reflector) and the polarizing plate integrated polarizing element obtained above were evaluated as follows. Table 2 shows the results. Table 2 also shows the conditions of each step in the examples and the comparative examples.
  • the reflection spectrum of the broadband cholesteric liquid crystal film is measured with a spectrophotometer (Otsuka Electronics Co., Ltd., Instant Multi-System MC PD 2000), and the selective reflection wavelength band is about half bandwidth. ⁇ was determined. The half bandwidth was defined as the reflection bandwidth at half the maximum reflectance. (Pitch change)
  • the polarizing plate integrated polarizing element was placed on a dot-printed backlight with the polarizing plate side facing up, and evaluated with a luminance meter (TOPCON, BM-7).
  • the oblique change in color tone of the liquid crystal display device was evaluated by a viewing angle measuring instrument EZ-CONTRAST manufactured by ELDIM, according to the following criteria.
  • Color tone change ⁇ Xy at a viewing angle of 60 ° is less than 0.04.
  • a cholesteric liquid crystal film having a selective reflection wavelength in a wide band including a long wavelength region is obtained.
  • the cholesteric liquid crystal film has high reliability, and a polarizing element using the cholesteric liquid crystal film as a circularly polarizing plate is also excellent in luminance enhancement characteristics.
  • the display information in the region where the gradation is not inverted is distributed by light diffusion in the oblique direction.
  • a display device can be obtained.
  • the broadband cholesteric liquid crystal film obtained by the production method of the present invention is useful as a circularly polarizing plate (reflection type polarizer), and the circularly polarizing plate is used for a linear polarizing element, an illumination device, a liquid crystal display device, and the like. Applicable.

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  • Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Nonlinear Science (AREA)
  • Mathematical Physics (AREA)
  • Polarising Elements (AREA)
  • Liquid Crystal (AREA)
  • Application Of Or Painting With Fluid Materials (AREA)
  • Coating Of Shaped Articles Made Of Macromolecular Substances (AREA)
  • Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)

Abstract

L'invention concerne un procédé de production de film à cristaux liquides cholestériques à large bande. Ledit procédé consiste : à appliquer un revêtement sur un substrat d'alignement au moyen d'un mélange de cristaux liquides contenant un composé mésogène polymérisable (A) et un agent chiral polymérisable (B) ; et à exposer ce mélange de cristaux liquides à un rayonnement ultraviolet, de sorte à réaliser la polymérisation et le durcissement. Cette étape de polymérisation par ultraviolet consiste : (1) à exposer le côté du substrat d'alignement du mélange de cristaux liquides, alors en contact avec un gaz oxygène, à un rayonnement ultraviolet, à une intensité de rayonnement ultraviolet comprise entre 20 et 200 mW/cm2, à une température de 20 °C ou supérieure, pendant 0,2 à 5 secondes ; (2) à le chauffer à une température comprise entre 70 et 120 °C, pendant 2 secondes au moins ; (3) à exposer le côté du substrat d'alignement de la couche de cristaux liquides à un rayonnement ultraviolet, à une intensité de rayonnement ultraviolet inférieure à celle de l'étape (1), à une température de 20 °C ou supérieure, pendant 10 secondes au moins ; et (4) à appliquer un rayonnement ultraviolet en l'absence d'oxygène. Ce procédé permet d'obtenir un film à cristaux liquides cholestériques à large bande présentant une large bande de réflexion, même dans une zone de longueur d'onde importante.
PCT/JP2004/003791 2003-03-31 2004-03-19 Procede de production d'un film a cristaux liquides cholesteriques a large bande, plaque de polarisation circulaire, polariseur lineaire, appareil d'eclairage et dispositif d'affichage a cristaux liquides WO2004088367A1 (fr)

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JP2003-093963 2003-03-31
JP2003390276A JP4293888B2 (ja) 2003-03-31 2003-11-20 広帯域コレステリック液晶フィルムの製造方法、円偏光板、直線偏光素子、照明装置および液晶表示装置
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JP4826182B2 (ja) * 2005-09-12 2011-11-30 日本ゼオン株式会社 塗膜形成装置
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JP5151228B2 (ja) * 2007-02-13 2013-02-27 日本ゼオン株式会社 円偏光分離シートの製法、並びにその製法で製造された円偏光分離シートを用いた液晶表示装置
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WO2009081735A1 (fr) * 2007-12-26 2009-07-02 Zeon Corporation Dispositif de rétroéclairage et dispositif d'affichage à cristaux liquides
JP2009192983A (ja) * 2008-02-18 2009-08-27 Nippon Zeon Co Ltd 選択反射素子及び液晶表示装置
JP5529600B2 (ja) * 2009-03-23 2014-06-25 日東電工株式会社 複合偏光板および液晶表示装置
WO2011013492A1 (fr) * 2009-07-29 2011-02-03 日本ゼオン株式会社 Film améliorant la luminosité, polariseur composite et dispositif d'affichage à cristaux liquides
US10293370B2 (en) 2009-10-24 2019-05-21 3M Innovative Properties Company Process for gradient nanovoided article
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CN103309074B (zh) 2013-05-24 2016-02-24 京东方科技集团股份有限公司 一种pdlc液晶面板的制备方法
JP2015079255A (ja) * 2014-11-11 2015-04-23 大日本印刷株式会社 光学フィルム、光学フィルム用転写体、画像表示装置
JP2017068111A (ja) * 2015-09-30 2017-04-06 富士フイルム株式会社 偏光板および液晶表示装置
WO2019093446A1 (fr) * 2017-11-08 2019-05-16 富士フイルム株式会社 Film optique stratifié et dispositif d'affichage électroluminescent organique
WO2025018426A1 (fr) * 2023-07-20 2025-01-23 富士フイルム株式会社 Procédé de production d'une couche de cristaux liquides cholestériques, couche de cristaux liquides cholestériques, film réfléchissant, verre feuilleté, système d'affichage tête haute et composition

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