Retardation film, polarizing plate, and liquid crystal display device

Abstract

The present invention addresses the problem of providing a retardation film with which it is possible to manufacture a liquid crystal display device excellent in planar shape and excellent in oblique contrast, and to provide a polarizing plate and a liquid crystal display device using the same. This retardation film has a support that has an in-plane retardation that exhibits reverse wavelength dispersibility, and a liquid crystal layer that is directly laminated on the support, wherein the support is a polymer film that has been subjected to stretching treatment in at least one direction in the plane thereof, the liquid crystal layer is a positive C plate obtained by fixing the alignment state of a liquid crystal composition containing a liquid crystal compound, the non-polar component of the surface energy of the surface on the side of the support on which the liquid crystal layer is laminated is less than 45 mN / m, the polar component is 2 mN / m or more, the half width of the peak of the power spectrum obtained by fast Fourier transform of the reflectance spectrum of the retardation film is 400 nm or less, and the haze value of the retardation film is 1.0% or less.

Description

Phase difference film, polarizing plate and liquid crystal display device

[0001] The present invention relates to a retardation film, a polarizing plate, and a liquid crystal display device.

[0002] Conventionally, polarizing plates having a retardation film and a polarizer have been used in liquid crystal displays, organic electroluminescent devices, etc. for the purpose of optical compensation, antireflection, etc. Patent Document 1, for example, describes a retardation film in such a polarizing plate as "a retardation film comprising a support and a liquid crystal layer formed in contact with the support using a liquid crystal composition containing a liquid crystal compound, wherein the surface energy of the support surface on which the liquid crystal layer is formed is 45 mN / m or more and the nonpolar dispersion force component contained in the surface energy is 45 mN / m or more, the liquid crystal compound is fixed in an aligned state, and the contrast is greater than 10,000" ([Claim 1]).

[0003] International Publication No. 2020 / 045224

[0004] The present inventors have studied the retardation film described in Patent Document 1 and have found that when a liquid crystal display device prepared using the retardation film is set to black display and observed from an oblique direction, in-plane unevenness may occur, resulting in poor surface quality. Furthermore, the present inventors have found that when a liquid crystal display device is prepared using a positive C plate, in which the alignment state of a liquid crystal composition is fixed, as the liquid crystal layer of the retardation film described in Patent Document 1, the contrast (white display brightness / black display brightness) (hereinafter abbreviated as "oblique contrast") may be poor when the brightness of black display and white display is observed from an oblique direction, depending on the materials and conditions for forming the support and the liquid crystal layer.

[0005] Therefore, an object of the present invention is to provide a retardation film that can be used to fabricate a liquid crystal display device that has excellent surface state and good oblique contrast, and a polarizing plate and a liquid crystal display device that use the retardation film.

[0006] As a result of intensive research into the above-mentioned problems, the present inventors have found that a liquid crystal display device having excellent surface condition and good oblique contrast can be fabricated by using a retardation film that has a support having a predetermined surface energy, an in-plane retardation exhibiting reverse wavelength dispersion, a predetermined liquid crystal layer laminated directly on the support, and a predetermined power spectrum half-width and haze value, and have thus completed the present invention. That is, the present inventors have found that the above-mentioned problems can be solved by the following configuration.

[0007] [1] A retardation film having a support whose in-plane retardation exhibits reverse wavelength dispersion and a liquid crystal layer laminated directly on the support, wherein the support is a polymer film stretched in at least one direction in its plane, the liquid crystal layer is a positive C-plate formed by fixing the alignment state of a liquid crystal composition containing a liquid crystal compound, the surface energy of the support on the side on which the liquid crystal layer is laminated is such that the nonpolar component is less than 45 mN / m and the polar component is 2 mN / m or more, the half-width of the peak of a power spectrum obtained by fast Fourier transform of the reflectance spectrum of the retardation film is 400 nm or less, and the haze value of the retardation film is 1.0% or less. [2] The retardation film according to [1], wherein the surface energy of the support on the side on which the liquid crystal layer is laminated is 45 mN / m or more. [3] The retardation film according to [1] or [2], wherein the material constituting the support is polycarbonate or polyester. [4] The retardation film according to any one of [1] to [3], wherein the support is a positive A plate. [5] The retardation film according to any one of [1] to [4], wherein the retardation in the thickness direction of the liquid crystal layer exhibits reverse wavelength dispersion. [6] The retardation film according to any one of [1] to [5], wherein the liquid crystal composition further contains a boronic acid monomer having a polymerizable group and a boronic acid group represented by formula (B) described later. [7] A polarizing plate comprising the retardation film according to any one of [1] to [6], and a polarizer. [8] The polarizing plate according to [7], wherein the absorption axis of the polarizer and the slow axis of the support of the retardation film are perpendicular or parallel to each other. [9] The polarizing plate according to [7], wherein the absorption axis of the polarizer and the slow axis of the support of the retardation film are parallel to each other.

[10] A liquid crystal display device comprising the polarizing plate according to any one of [7] to [9].

[0008] As will be described below, the present invention can provide a retardation film that can be used to fabricate a liquid crystal display device that has excellent surface state and good oblique contrast, as well as a polarizing plate and a liquid crystal display device that use the retardation film.

[0009] The following description of the constituent elements may be based on a representative embodiment of the present invention, but the present invention is not limited to such an embodiment. In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the upper and lower limits. In this specification, the upper or lower limit of a numerical range described in stages may be replaced with the upper or lower limit of another numerical range described in stages. In this specification, the upper or lower limit of a numerical range described in stages may be replaced with a value shown in the examples. In this specification, the terms "perpendicular" and "parallel" refer to angles within a range of ±10°, and the terms "same" and "different" refer to angles that are determined based on whether the difference is less than 5°. In this specification, "visible light" refers to 380 to 780 nm. In this specification, unless otherwise specified, the measurement wavelength is 550 nm. In addition, the bonding direction of the divalent group (for example, —O—CO—) described in this specification is not particularly limited. １ -L ２ -L ３ In the bond ２ When is —O—CO—, L １ The position where it is bonded to the side is *1, L ３ If the position bonded to the side is *2, then L ２ may be *1-O-CO-*2 or *1-CO-O-*2. Next, the terms used in this specification will be explained.

[0010] [Slow Axis] In this specification, the term "slow axis" refers to the direction in which the refractive index is maximum in the plane. The slow axis of a retardation film refers to the slow axis of the entire retardation film.

[0011] [Re(λ), Rth(λ)] In this specification, Re(λ) and Rth(λ) represent the in-plane retardation and the thickness direction retardation, respectively, at a wavelength λ. Unless otherwise specified, the wavelength λ is 550 nm. Here, the in-plane retardation and the thickness direction retardation values ​​are values ​​measured using an AxoScan OPMF-1 (manufactured by Optoscience) with light of the measurement wavelength. Specifically, by inputting the average refractive index ((Nx + Ny + Nz) / 3) and the film thickness (d (μm)) into the AxoScan OPMF-1, the following slow axis direction (°) Re(λ) = R0(λ) Rth(λ) = ((nx + ny) / 2 - nz) × d are calculated. Note that R0(λ) is displayed as a numerical value calculated by AxoScan OPMF-1, but it means Re(λ).

[0012] [Substituent] In this specification, examples of the substituent (monovalent substituent) include the substituents described below in Substituent Group A. In this specification, the phrase "optionally having a substituent" includes not only an embodiment in which no substituent is present, but also an embodiment in which one or more substituents are present. <Substituent Group A> Examples of the substituent include halogen atoms (for example, fluorine atoms, chlorine atoms, and bromine atoms, preferably chlorine atoms and fluorine atoms, and more preferably fluorine atoms); alkyl groups (preferably linear, branched, or cyclic alkyl groups having 1 to 48 carbon atoms, more preferably 1 to 24 carbon atoms, and particularly preferably 1 to 8 carbon atoms, such as linear alkyl groups having 1 to 6 carbon atoms (for example, methyl, ethyl, n-propyl, n-butyl, n-pentyl, and n-hexyl), branched alkyl groups having 3 to 6 carbon atoms (for example, isopropyl, isobutyl, tert-butyl, sec-butyl, neopentyl, isohexyl, and 3-methylpentyl), and cyclic alkyl groups having 3 to 12 carbon atoms (for example, cyclopropyl, cyclopentyl, cyclohexyl, 1-norbornyl, and 1-adamantyl)); alkenyl groups (preferably alkenyl groups having 2 to 48 carbon atoms, more preferably 2 to 18 carbon atoms, such as vinyl groups, allyl groups, 1-butenyl groups, and 2-butenyl groups); alkynyl groups (preferably alkynyl groups having 2 to 6 carbon atoms, more preferably 2 to 4 carbon atoms, such as ethynyl groups, 1-propynyl groups, propargyl groups, 1-butynyl groups, and 2-butynyl groups); aryl groups (preferably aryl groups having 6 to 48 carbon atoms, more preferably 6 to 24 carbon atoms, such as phenyl groups, oligoaryl groups (naphthyl groups, anthryl groups), phenanthrenyl groups, fluorenyl groups, pyrenyl groups, triphenylenyl groups, and biphenyl groups); Heteroaryl groups (preferably heterocyclic groups having 1 to 32 carbon atoms, more preferably 1 to 18 carbon atoms, such as a 2-thienyl group, a 4-pyridyl group, a 2-furyl group, a 2-pyrimidinyl group, a 1-pyridyl group, a 2-benzothiazolyl group, a 1-imidazolyl group, a 1-pyrazolyl group, or a benzotriazol-1-yl group);arylalkyl groups (preferably arylalkyl groups having 7 to 15 carbon atoms, for example, benzyl group, phenethyl group, methylbenzyl group, phenylpropyl group, 1-methylphenylethyl group, phenylbutyl group, 2-methylphenylpropyl group, tetrahydronaphthyl group, naphthylmethyl group, naphthylethyl group, indenyl group, fluorenyl group, anthracenylmethyl group (anthrylmethyl group), phenanthrenylmethyl group (phenanthrylmethyl group)); silyl groups (preferably silyl groups having 3 to 38 carbon atoms, more preferably 3 to 18 carbon atoms, for example, trimethylsilyl group, triethylsilyl group, tributylsilyl group, t-butyldimethylsilyl group, t-hexyldimethylsilyl group); hydroxy groups; cyano groups; nitro groups; morpholino groups; Alkoxy groups (preferably alkoxy groups having 1 to 48 carbon atoms, more preferably 1 to 24 carbon atoms, for example, methoxy, ethoxy, 1-butoxy, 2-butoxy, isopropoxy, t-butoxy, dodecyloxy, and cycloalkyloxy groups (for example, cyclopentyloxy and cyclohexyloxy)); aryloxy groups (preferably aryloxy groups having 6 to 48 carbon atoms, more preferably 6 to 24 carbon atoms, for example, phenoxy and 1-naphthoxy); alkenyloxy groups (preferably alkenyloxy groups having 2 to 6 carbon atoms, for example, vinyloxy, 1-propenyloxy, 2-n-propenyloxy (allyloxy), 1-n-butenyloxy, and prenyloxy); heterocyclic oxy groups (preferably heterocyclic oxy groups having 1 to 32 carbon atoms, more preferably 1 to 18 carbon atoms, such as a 1-phenyltetrazole-5-oxy group or a 2-tetrahydropyranyloxy group); silyloxy groups (preferably silyloxy groups having 1 to 32 carbon atoms, more preferably 1 to 18 carbon atoms, such as a trimethylsilyloxy group, a t-butyldimethylsilyloxy group or a diphenylmethylsilyloxy group); acyloxy groups (preferably acyloxy groups having 2 to 48 carbon atoms, more preferably 2 to 24 carbon atoms, such as an acetoxy group, a pivaloyloxy group, a benzoyloxy group, a dodecanoyloxy group, an acryloyloxy group or a methacryloyloxy group);hydroxyalkyleneoxy groups (preferably hydroxyalkyleneoxy groups having 2 to 10 carbon atoms, for example, a hydroxyethyleneoxy group); alkoxycarbonyloxy groups (preferably alkoxycarbonyloxy groups having 2 to 48 carbon atoms, more preferably 2 to 24 carbon atoms, for example, an ethoxycarbonyloxy group, a t-butoxycarbonyloxy group, or a cycloalkyloxycarbonyloxy group (for example, a cyclohexyloxycarbonyloxy group)); aryloxycarbonyloxy groups (preferably aryloxycarbonyloxy groups having 7 to 32 carbon atoms, more preferably 7 to 24 carbon atoms, for example, a phenoxycarbonyloxy group); carbamoyloxy groups (preferably carbamoyloxy groups having 1 to 48 carbon atoms, more preferably 1 to 24 carbon atoms, for example, an N,N-dimethylcarbamoyloxy group, an N-butylcarbamoyloxy group, an N-phenylcarbamoyloxy group, or an N-ethyl-N-phenylcarbamoyloxy group); sulfamoyloxy groups (preferably sulfamoyloxy groups having 1 to 32 carbon atoms, more preferably 1 to 24 carbon atoms, such as an N,N-diethylsulfamoyloxy group or an N-propylsulfamoyloxy group); alkylsulfonyloxy groups (preferably alkylsulfonyloxy groups having 1 to 38 carbon atoms, more preferably 1 to 24 carbon atoms, such as a methylsulfonyloxy group, a hexadecylsulfonyloxy group or a cyclohexylsulfonyloxy group); arylsulfonyloxy groups (preferably arylsulfonyloxy groups having 6 to 32 carbon atoms, more preferably 6 to 24 carbon atoms, such as a phenylsulfonyloxy group); acyl groups (preferably acyl groups having 1 to 48 carbon atoms, more preferably 1 to 24 carbon atoms, such as a formyl group, an acetyl group, an acryloyl group, a methacryloyl group, a pivaloyl group, a benzoyl group, a tetradecanoyl group or a cyclohexanoyl group); an alkoxycarbonyl group (preferably an alkoxycarbonyl group having 2 to 48 carbon atoms, more preferably 2 to 24 carbon atoms, for example, a methoxycarbonyl group, an ethoxycarbonyl group, an octadecyloxycarbonyl group, a cyclohexyloxycarbonyl group, or a 2,6-di-tert-butyl-4-methylcyclohexyloxycarbonyl group);an aryloxycarbonyl group (preferably an aryloxycarbonyl group having 7 to 32 carbon atoms, more preferably an aryloxycarbonyl group having 7 to 24 carbon atoms, for example, a phenoxycarbonyl group); a carbamoyl group (preferably a carbamoyl group having 1 to 48 carbon atoms, more preferably a carbamoyl group having 1 to 24 carbon atoms, for example, a carbamoyl group, N,N-diethylcarbamoyl group, N-ethyl-N-octylcarbamoyl group, N,N-dibutylcarbamoyl group, N-propylcarbamoyl group, N-phenylcarbamoyl group, N-methyl-N-phenylcarbamoyl group, or N,N-dicyclohexylcarbamoyl group); an amino group (preferably an amino group having 32 or less carbon atoms, more preferably an amino group having 24 or less carbon atoms, for example, an amino group, a methylamino group, an N,N-dimethylamino group, an N,N-dibutylamino group, a tetradecylamino group, a 2-ethylhexylamino group, or a cyclohexylamino group); anilino group (preferably an anilino group having 6 to 32 carbon atoms, more preferably 6 to 24 carbon atoms, for example, an anilino group, an N-methylanilino group); heterocyclic amino group (preferably a heterocyclic amino group having 1 to 32 carbon atoms, more preferably 1 to 18 carbon atoms, for example, a 4-pyridylamino group); carbonamido group (preferably a carbonamido group having 2 to 48 carbon atoms, more preferably 2 to 24 carbon atoms, for example, an acetamido group, a benzamido group, a tetradecanamido group, a pivaloylamido group, a cyclohexanamido group); ureido group (preferably a ureido group having 1 to 32 carbon atoms, more preferably 1 to 24 carbon atoms, for example, a ureido group, an N,N-dimethylureido group, an N-phenylureido group); imido group (preferably an imido group having 36 or less carbon atoms, more preferably 24 or less carbon atoms, for example, an N-succinimido group, an N-phthalimido group); an alkoxycarbonylamino group (preferably an alkoxycarbonylamino group having 2 to 48 carbon atoms, more preferably 2 to 24 carbon atoms, for example, a methoxycarbonylamino group, an ethoxycarbonylamino group, a t-butoxycarbonylamino group, an octadecyloxycarbonylamino group, or a cyclohexyloxycarbonylamino group); an aryloxycarbonylamino group (preferably an aryloxycarbonylamino group having 7 to 32 carbon atoms, more preferably 7 to 24 carbon atoms, for example, a phenoxycarbonylamino group);sulfonamido groups (preferably sulfonamido groups having 1 to 48 carbon atoms, more preferably 1 to 24 carbon atoms, for example, methanesulfonamido groups, butanesulfonamido groups, benzenesulfonamido groups, hexadecanesulfonamido groups, and cyclohexanesulfonamido groups); sulfamoylamino groups (preferably sulfamoylamino groups having 1 to 48 carbon atoms, more preferably 1 to 24 carbon atoms, for example, N,N-dipropylsulfamoylamino groups, and N-ethyl-N-dodecylsulfamoylamino groups); azo groups (preferably azo groups having 1 to 32 carbon atoms, more preferably 1 to 24 carbon atoms, for example, phenylazo groups and 3-pyrazolylazo groups); alkylthio groups (preferably alkylthio groups having 1 to 48 carbon atoms, more preferably 1 to 24 carbon atoms, for example, methylthio groups, ethylthio groups, octylthio groups, and cyclohexylthio groups); an arylthio group (preferably an arylthio group having 6 to 48 carbon atoms, more preferably an arylthio group having 6 to 24 carbon atoms, for example, a phenylthio group); a heterocyclic thio group (preferably a heterocyclic thio group having 1 to 32 carbon atoms, more preferably a heterocyclic thio group having 1 to 18 carbon atoms, for example, a 2-benzothiazolylthio group, a 2-pyridylthio group, or a 1-phenyltetrazolylthio group); an alkylsulfinyl group (preferably an alkylsulfinyl group having 1 to 32 carbon atoms, more preferably an alkylsulfinyl group having 1 to 24 carbon atoms, for example, a dodecanesulfinyl group); an arylsulfinyl group (preferably an arylsulfinyl group having 6 to 32 carbon atoms, more preferably an arylsulfinyl group having 6 to 24 carbon atoms, for example, a phenylsulfinyl group); alkylsulfonyl groups (preferably alkylsulfonyl groups having 1 to 48 carbon atoms, more preferably 1 to 24 carbon atoms, for example, methylsulfonyl, ethylsulfonyl, propylsulfonyl, butylsulfonyl, isopropylsulfonyl, 2-ethylhexylsulfonyl, hexadecylsulfonyl, octylsulfonyl, and cyclohexylsulfonyl groups); arylsulfonyl groups (preferably arylsulfonyl groups having 6 to 48 carbon atoms, more preferably 6 to 24 carbon atoms, for example, phenylsulfonyl, and 1-naphthylsulfonyl groups);sulfamoyl groups (preferably sulfamoyl groups having 32 or less carbon atoms, more preferably 24 or less carbon atoms, for example, a sulfamoyl group, an N,N-dipropylsulfamoyl group, an N-ethyl-N-dodecylsulfamoyl group, an N-ethyl-N-phenylsulfamoyl group, an N-cyclohexylsulfamoyl group, or an N-(2-ethylhexyl)sulfamoyl group); phosphonyl groups (preferably phosphonyl groups having 1 to 32 carbon atoms, more preferably 1 to 24 carbon atoms, for example, a phenoxyphosphonyl group, an octyloxyphosphonyl group, or a phenylphosphonyl group); phosphinoylamino groups (preferably phosphinoylamino groups having 1 to 32 carbon atoms, more preferably 1 to 24 carbon atoms, for example, a diethoxyphosphinoylamino group, or a dioctyloxyphosphinoylamino group); epoxy groups; —NHCOCH; ３ ;-SO ２ NHC ２ H ４ OCH ３ ;-NHSO ２ CH ３ and the like, and two or more of these may be combined. These substituents may be further substituted with other substituents. When two or more substituents are present, they may be the same or different. If possible, they may be bonded to each other to form a ring.

[0013] [Retardation Film] The retardation film of the present invention has a support whose in-plane retardation exhibits reverse wavelength dispersion and a liquid crystal layer directly laminated on the support. The support of the retardation film of the present invention is a polymer film stretched in at least one direction in-plane. The liquid crystal layer of the retardation film of the present invention is a positive C-plate formed by fixing the alignment state of a liquid crystal composition containing a liquid crystal compound. The retardation film of the present invention has a surface energy of the support on the side on which the liquid crystal layer is laminated, in which the nonpolar component is less than 45 mN / m and the polar component is 2 mN / m or more. The retardation film of the present invention has a half-width of 400 nm or less of the peak of the power spectrum obtained by fast Fourier transform of the reflectance spectrum. The retardation film of the present invention has a haze value of 1.0% or less.

[0014] [Half-Width of Power Spectrum Peak] The half-width of the power spectrum peak refers to a value calculated by the following procedure. First, a sample is prepared by attaching a black-painted polyethylene terephthalate (PET) film to the surface of the support of the retardation film on the side where the liquid crystal layer is not provided. The prepared sample is set in a reflection spectroscopic film thickness meter (FE-3000, manufactured by Otsuka Electronics Co., Ltd.), and the reflectance spectrum of the side of the retardation film where the black PET is not attached is measured using a D2 lamp light source. Next, the measured spectrum is subjected to a fast Fourier transform to determine the power spectrum relative to the film thickness. Next, the half-width of the peak originating from the interface between the support and the liquid crystal layer in the obtained power spectrum is determined. The measurement conditions for the reflectance spectrum using the FE-3000, as well as the calculation method and calculation wavelength range of the fast Fourier transform, are as follows: Measurement method: absolute reflectance Calculation method: FFT (Fast Fourier Transform) Calculation wavelength range for FFT analysis: 310.00 to 760.00 nm

[0015] [Haze Value] The haze value refers to the haze measured in accordance with JIS K7136:2000 "Method for determining haze of plastic transparent materials," and refers to the value measured using a haze meter (for example, NDH4000 (manufactured by Nippon Denshoku Industries Co., Ltd.)) in an environment of 25°C and a relative humidity of 55%.

[0016] In the present invention, a liquid crystal display device having excellent surface condition and good oblique contrast can be produced by, for example, setting the surface energy of the support on the side on which the liquid crystal layer is laminated to a non-polar component of less than 45 mN / m and a polar component of 2 mN / m or more, and setting the half-width of the peak of the power spectrum obtained by fast Fourier transform of the reflectance spectrum of the retardation film to 400 nm or less. The mechanism behind this is not clear in detail, but is presumed to be roughly as follows. That is, it is thought that the surface energy of the support on the side on which the liquid crystal layer is laminated, particularly the polar component, of 2 mN / m or more, makes the interface state between the support and the liquid crystal layer uniform within the film plane, resulting in good surface condition. Furthermore, the fact that the half-width of the peak of the power spectrum obtained by fast Fourier transform of the reflectance spectrum of the retardation film is 400 nm or less is considered to be due to the fact that the boundary region between the support and the liquid crystal layer is clear, that is, the presence of a mixed region where components of the support have infiltrated into the liquid crystal layer is suppressed, and therefore the alignment of the liquid crystal layer (a positive C plate obtained by fixing the alignment state of a liquid crystal composition containing a liquid crystal compound) is not disturbed, resulting in good diagonal contrast.

[0017] As described above, the retardation film of the present invention has a power spectrum obtained by fast Fourier transform of the reflectance spectrum, whose peak half width is 400 nm or less, preferably 100 nm or more and less than 400 nm, more preferably 200 nm or more and 390 nm or less, and even more preferably 300 nm or more and 380 nm or less. In the present invention, the power spectrum peak half width can be adjusted by the type of solvent of the liquid crystal composition used in forming the liquid crystal layer, as is clear from the results of the Examples and Comparative Examples described later.

[0018] As described above, the haze value of the retardation film of the present invention is 1.0% or less, preferably 0.1% or more and 0.8% or less, more preferably 0.1% or more and 0.5% or less, and even more preferably 0.1% or more and less than 0.5%. In the present invention, the haze value of the retardation film can be adjusted by the type of solvent of the liquid crystal composition used in forming the liquid crystal layer, as is clear from the results of the Examples and Comparative Examples described later.

[0019] The thickness of the retardation film of the present invention is preferably 2 to 210 μm, more preferably 3 to 110 μm, and further preferably 5 to 80 μm. When the retardation film has a plurality of layers, the thickness of the retardation film refers to the total thickness including the layers.

[0020] [Support] The support of the retardation film of the present invention is a support whose in-plane retardation exhibits reverse wavelength dispersion. Here, "in-plane retardation exhibits reverse wavelength dispersion" means that when the in-plane retardation (Re) value of a layer (film) is measured at a specific wavelength (visible light range), the Re value increases as the measured wavelength increases, and in the present invention, this means that the relationship Re(450) / Re(550)<1.00 is satisfied. Furthermore, the support preferably has Re(450) / Re(550) of 0.60 or more and 1.00 or less, more preferably 0.70 or more and 1.00 or less, and even more preferably 0.75 or more and 0.95 or less. Furthermore, the in-plane retardation of the support preferably satisfies the relationship Re(650) / Re(550)>1.00. Re(650) / Re(550) is preferably 1.00 or more and 1.30 or less, more preferably 1.00 or more and 1.25 or less, and even more preferably 1.00 or more and 1.20 or less.

[0021] In addition, the support of the retardation film of the present invention is a polymer film that has been stretched in at least one direction in plane, and is preferably a polymer film that has been stretched uniaxially or biaxially.The material of such a polymer film can be polycarbonate; polyolefins such as polyethylene and polypropylene; polyesters such as polyethylene terephthalate and polybutylene terephthalate; polyarylene sulfides such as polyphenylene sulfide; polyvinyl alcohol; polyarylate; cellulose ester polymers such as cellulose acylate; polyethersulfone; polysulfone; polyallylsulfone; polyvinyl chloride; cyclic olefin polymers such as norbornene polymer; etc. Among these, polycarbonate or polyester is preferred because the orientation of the retardation film is good and the adhesion between the support and the liquid crystal layer is good.

[0022] The support of the retardation film of the present invention has a surface energy (hereinafter also simply referred to as "surface energy") on the surface of the support on which the liquid crystal layer is laminated, in which the nonpolar component is less than 45 mN / m and the polar component is 2 mN / m or more. ｖ : unit, mN / m), non-polar component (γs ｄ : unit, mN / m), and polar component (γs ｈ The surface tension (unit: mN / m) is measured by dissolving pure water H on the surface of the support to be measured, with reference to D. K. Owens: J. Appl. Polym. Sci., 13, 1741 (1969). ２ O and methylene iodide CH ２ I ２ In this case, the contact angles of pure water and methylene iodide can be determined experimentally using θ Ｈ２Ｏ and θ ＣＨ２Ｉ２ Then, γs is calculated by the following simultaneous equations (SA) and (SB). ｄ and γs ｈ and the value γs ｖ (=γs ｄ +γs ｈThe contact angle is defined as 1+cosθ. The contact angle is measured in an environment of 20°C to 27°C and 50% to 65% relative humidity for at least 2 hours, and then in an environment of 25°C and 60% relative humidity, using a contact angle meter (for example, Dropmaster (manufactured by Kyowa Interface Science Co., Ltd.)). Ｈ２Ｏ = 2√γs ｄ (√γ Ｈ２Ｏ ｄ / γ Ｈ２Ｏ ｖ ) + 2√γs ｈ (√γ Ｈ２Ｏ ｈ / γ Ｈ２Ｏ ｖ )...(SA) 1+cosθ ＣＨ２Ｉ２ = 2√γs ｄ (√γ ＣＨ２Ｉ２ ｄ / γ ＣＨ２Ｉ２ ｖ ) + 2√γs ｈ (√γ ＣＨ２Ｉ２ ｈ / γ ＣＨ２Ｉ２ ｖ ) ... (SB) (where γ Ｈ２Ｏ ｄ = 21.8, γ Ｈ２Ｏ ｈ = 51.0, γ Ｈ２Ｏ ｖ = 72.8, γ ＣＨ２Ｉ２ ｄ = 49.5, γ ＣＨ２Ｉ２ ｈ = 1.3, γ ＣＨ２Ｉ２ ｖ = 50.8.)

[0023] In the present invention, the surface energy of the support is preferably 45 mN / m or more, more preferably 45 to 70 mN / m, and even more preferably 48 to 60 mN / m, because this improves the adhesion between the support and the liquid crystal layer and improves the diagonal contrast of the liquid crystal display device. Furthermore, the non-polar component of the support surface energy is less than 45 mN / m, but because this improves the surface condition, it is preferably 40 mN / m or less, more preferably 10 to 40 mN / m, and even more preferably 20 to 40 mN / m. Furthermore, the polar component of the support surface energy is 2 mN / m or more, but because this improves the surface condition, it is preferably 2 to 35 mN / m, more preferably 5 to 35 mN / m, and even more preferably 10 to 30 mN / m. In the present invention, the surface energy of the support can be adjusted by a surface treatment (e.g., corona treatment, etc.) applied to the support surface, as is clear from the results of Examples 1 and 2 described below.

[0024] In the present invention, the support is preferably a positive A plate because this improves display performance when used in a liquid crystal display device. In this specification, a positive A plate is defined as follows. Specifically, a positive A plate satisfies the relationship of formula (A1), where nx is the refractive index in the slow axis direction (the direction in which the in-plane refractive index is maximum) in the film plane, ny is the refractive index in the direction perpendicular to the in-plane slow axis, and nz is the refractive index in the thickness direction. A positive A plate exhibits a positive Rth. Formula (A1) nx>ny≒nz. The above "≒" encompasses not only cases where the two are completely identical, but also cases where the two are substantially identical. "Substantially identical" also includes, for example, cases where (ny-nz)×d (where d is the film thickness) is -10 to 10 nm, preferably -5 to 5 nm, in "ny≒nz." The Re(550) of the support is preferably 10 nm or more and 300 nm or less, more preferably 50 nm or more and 200 nm or less, and even more preferably 100 nm or more and 160 nm or less. The Rth(550) of the support is preferably 10 nm or more and 200 nm or less, more preferably 50 nm or more and 150 nm or less, and even more preferably 60 nm or more and 130 nm or less.

[0025] In the present invention, the support is preferably transparent. The term "transparent" as used herein refers to a visible light transmittance of 60% or more, preferably 80% or more, and more preferably 90% or more. The thickness of the support is not particularly limited, but is preferably 1 to 200 μm, and more preferably 2 to 100 μm.

[0026] [Liquid Crystal Layer] The liquid crystal layer of the retardation film of the present invention is a liquid crystal layer directly laminated on the support, i.e., no other member (for example, a so-called alignment film) exists between the support and the liquid crystal layer.

[0027] The liquid crystal layer of the retardation film of the present invention is a positive C plate obtained by fixing the alignment state of a liquid crystal composition containing a liquid crystal compound. Here, since the liquid crystal layer fixes the alignment state of the liquid crystal composition as described above, the liquid crystal compound contained in the liquid crystal layer no longer needs to exhibit liquid crystallinity. In this specification, the positive C plate is defined as follows. Specifically, a positive C plate (positive C plate) satisfies the relationship of formula (C1), where nx is the refractive index in the in-plane slow axis direction (the direction in which the in-plane refractive index is maximum) of the liquid phase layer, ny is the refractive index in the direction perpendicular to the in-plane slow axis, and nz is the refractive index in the thickness direction. The positive C plate exhibits a negative Rth. Formula (C1) nx ≒ ny < nz. The above "≒" encompasses not only the case where the two are completely identical, but also the case where the two are substantially identical. "Substantially the same" means that, for example, "nx ≒ ny" also includes a case where (nx - ny) x d (where d is the film thickness) is 0 to 10 nm, preferably 0 to 5 nm. The Re(550) of the liquid crystal layer is preferably 0 nm or more and 10 nm or less, more preferably 0 nm or more and 5 nm or less, and even more preferably 0 nm or more and 2 nm or less. The Rth(550) of the liquid crystal layer is preferably -200 nm or more and -10 nm or less, more preferably -180 nm or more and -50 nm or less, and even more preferably -150 nm or more and -80 nm or less.

[0028] In the present invention, the liquid crystal layer preferably exhibits reverse wavelength dispersion because this improves the display performance when used in a liquid crystal display device. More specifically, it is preferable that the thickness direction retardation exhibits reverse wavelength dispersion. Here, "thickness direction retardation exhibits reverse wavelength dispersion" refers to a state in which, when the thickness direction retardation (Rth) value of the liquid crystal layer alone is measured at a specific wavelength (visible light range), the absolute value of the Rth value increases as the measured wavelength increases. In the present invention, this refers to a state in which the relationship Rth(450) / Rth(550)<1.00 is satisfied. Furthermore, the liquid crystal layer preferably has an Rth(450) / Rth(550) ratio of 0.60 to 1.10, more preferably 0.70 to 1.00, and even more preferably 0.75 to 0.95. Furthermore, the thickness direction retardation of the liquid crystal layer preferably satisfies the relationship Rth(650) / Rth(550)>1.00. Rth(650) / Rth(550) is preferably 1.00 or more and 1.30 or less, more preferably 1.00 or more and 1.25 or less, and even more preferably 1.00 or more and 1.20 or less.

[0029] In the present invention, the thickness of the liquid crystal layer is not particularly limited, but is preferably 0.5 to 5 μm, more preferably 0.5 to 4 μm, and even more preferably 0.5 to 3 μm.

[0030] <Liquid Crystal Composition> As described above, the liquid crystal layer of the retardation film of the present invention is a positive C plate obtained by fixing the alignment state of a liquid crystal composition containing a liquid crystal compound.

[0031] (Liquid Crystal Compound) The liquid crystal compound contained in the liquid crystal composition is not particularly limited, and conventionally known liquid crystal compounds can be used. Generally, liquid crystal compounds can be classified into rod-shaped and discotic types based on their shape. Each type can further be divided into low-molecular-weight and high-molecular-weight types. High-molecular-weight compounds generally refer to those with a degree of polymerization of 100 or more (see "Polymer Physics: Phase Transition Dynamics," by Masao Doi, p. 2, Iwanami Shoten, 1992). While any liquid crystal compound can be used in the present invention, rod-shaped or discotic liquid crystal compounds (discotic liquid crystal compounds) are preferred. Two or more rod-shaped liquid crystal compounds, two or more discotic liquid crystal compounds, or a mixture of rod-shaped and discotic liquid crystal compounds may also be used. As the rod-shaped liquid crystal compound, for example, those described in claim 1 of JP-A-11-513019 and paragraphs

[0026] to

[0098] of JP-A-2005-289980 can be preferably used, and as the discotic liquid crystal compound, for example, those described in paragraphs

[0020] to

[0067] of JP-A-2007-108732 and paragraphs

[0013] to

[0108] of JP-A-2010-244038 can be preferably used, but are not limited to these.

[0032] In the present invention, the liquid crystal compound preferably has a polymerizable group, more preferably two or more polymerizable groups, to improve the durability of the liquid crystal layer. Here, the polymerizable group is not particularly limited, but a polymerizable group capable of radical polymerization or cation polymerization is preferred. As the radical polymerizable group, known radical polymerizable groups can be used, and preferred examples include an acryloyloxy group or a methacryloyloxy group. In this case, the acryloyloxy group is generally known to have a faster polymerization rate, and from the viewpoint of improving productivity, an acryloyloxy group is preferred, but a methacryloyloxy group can also be used as the polymerizable group. As the cationically polymerizable group, known cationically polymerizable groups can be used, and specific examples include an alicyclic ether group, a cyclic acetal group, a cyclic lactone group, a cyclic thioether group, a spiro orthoester group, and a vinyloxy group. Among these, an alicyclic ether group or a vinyloxy group is preferred, and an epoxy group, an oxetanyl group, or a vinyloxy group is particularly preferred. Particularly preferred examples of the polymerizable group include polymerizable groups represented by any one of the following formulae (P-1) to (P-20).

[0033]

[0034] In the present invention, the liquid crystal compound is preferably a liquid crystal compound having reverse wavelength dispersion, and more preferably a compound represented by the following formula (A), for the reason that the orientation of the retardation film is good. １ -SP １ -D ５ - (A １ ) ａ１ -D ３ - (G １ ) ｇ１ -D １ -Ar-D ２ - (G ２ ) ｇ２ -D ４ - (A ２ ) ａ２ -D ６ -SP ２ -L ２ (A)

[0035] In the above formula (A), a1, a2, g1, and g2 each independently represent 0 or 1. However, at least one of a1 and g1 represents 1, and at least one of a2 and g2 represents 1. １ , D ２ , D ３ , D ４ , D ５ and D ６ each independently represents a single bond, or —CO—, —O—, —S—, —C(═S)—, or —CR １ R ２ -, -CR ３ =CR ４ -, -NR ５ -, or a divalent linking group formed by a combination of two or more thereof, R １ ~R ５ each independently represents a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 12 carbon atoms. １ and G ２ each independently represents an aromatic ring having 6 to 20 carbon atoms which may have a substituent, or a divalent alicyclic hydrocarbon group having 5 to 20 carbon atoms which may have a substituent, and -CH ２ One or more of - may be substituted with -O-, -S- or -NH-. １ and A ２ each independently represents an aromatic ring having 6 to 20 carbon atoms which may have a substituent, or a divalent alicyclic hydrocarbon group having 5 to 20 carbon atoms which may have a substituent, and -CH ２ One or more of - may be substituted with -O-, -S- or -NH-. １ and SP ２ each independently represents a single bond or a divalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, provided that —CH ２ One or more of - may be substituted with -O-, -S-, -NH-, -N(Q)- or -CO-. Q represents a substituent. １ and L ２ each independently represents a monovalent organic group; １and L ２ At least one of the groups represented by the formula (Ar-3) below represents a polymerizable group. １ and L ２ and L in the following formula (Ar-3): ３ and L ４ At least one of the following represents a polymerizable group. Ar represents an aromatic ring selected from the group consisting of groups represented by formulas (Ar-1) to (Ar-7) described below.

[0036] In the above formula (A), a1, a2, g1, and g2 are preferably all 1 because the liquid crystal composition is more likely to exhibit a smectic liquid crystal state. In addition, it is preferable that a1 and a2 are all 0 and g1 and g2 are all 1 because the durability of the liquid crystal layer to be produced is improved.

[0037] In the above formula (A), D １ , D ２ , D ３ , D ４ , D ５ and D ６ Examples of the divalent linking group represented by one embodiment of the formula (I) include -CO-, -O-, -S-, -C(=S)-, and -CR １ R ２ -, -CR ３ =CR ４ -, -NR ５ -, or a divalent linking group formed by a combination of two or more thereof. １ ~R ５ each independently represents a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 12 carbon atoms. Specific examples of the divalent linking group include -CO-, -O-, -CO-O-, -C(=S)O-, and -CR １ R ２ -, -CR １ R ２ -CR １ R ２ -, -O-CR １ R ２ -, -CR １ R ２ -O-CR １ R ２ -, -CO-O-CR１ R ２ -, -O-CO-CR １ R ２ -, -CR １ R ２ -O-CO-CR １ R ２ -, -CR １ R ２ -CO-O-CR １ R ２ -, -NR ５ -CR １ R ２ -, and -CO-NR ５ -, etc. １ , R ２ and R ５ each independently represents a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 12 carbon atoms. Among these, any of —CO—, —O—, and —CO—O— is preferred.

[0038] In the above formula (A), G １ and G ２ Examples of the aromatic ring having 6 to 20 carbon atoms represented by one embodiment of the formula (1) include aromatic hydrocarbon rings such as a benzene ring, a naphthalene ring, an anthracene ring, and a phenanthroline ring; and aromatic heterocycles such as a furan ring, a pyrrole ring, a thiophene ring, a pyridine ring, a thiazole ring, and a benzothiazole ring. Of these, a benzene ring (for example, a 1,4-phenyl group) is preferred.

[0039] In the above formula (A), G １ and G ２ The divalent alicyclic hydrocarbon group having 5 to 20 carbon atoms represented by one embodiment of the formula (1) is preferably a 5-membered or 6-membered ring. The alicyclic hydrocarbon group may be saturated or unsaturated, but is preferably a saturated alicyclic hydrocarbon group. １ and G ２ For the divalent alicyclic hydrocarbon group represented by the formula (I), reference can be made to, for example, paragraph

[0078] of JP-A-2012-21068, the contents of which are incorporated herein by reference.

[0040] In the present invention, the durability of the liquid crystal layer to be produced is improved by adjusting the G １ and G２ is preferably a cycloalkane ring. Specific examples of the cycloalkane ring include a cyclohexane ring, a cycloheptane ring, a cyclooctane ring, a cyclododecane ring, and a cyclodocosane ring. Of these, a cyclohexane ring is preferred, a 1,4-cyclohexylene group is more preferred, and a trans-1,4-cyclohexylene group is even more preferred.

[0041] In addition, in the above formula (A), G １ and G ２ With regard to the above, examples of the substituent that the aromatic ring having 6 to 20 carbon atoms or the divalent alicyclic hydrocarbon group having 5 to 20 carbon atoms may have include the substituents described in the above-mentioned substituent group A, and among them, an alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group, or a halogen atom is preferable.

[0042] In the above formula (A), A １ and A ２ The aromatic ring having 6 to 20 carbon atoms in one embodiment of the formula (A) is G １ and G ２ In addition, in the above formula (A), A １ and A ２ The divalent alicyclic hydrocarbon group having 5 to 20 carbon atoms represented by one embodiment of the formula (A) is G １ and G ２ The same as those explained in A １ and A ２ With respect to the above, examples of the substituent that the aromatic ring having 6 to 20 carbon atoms or the divalent alicyclic hydrocarbon group having 5 to 20 carbon atoms may have include G １ and G ２ Examples of the substituents include the same as those that may be possessed by the group.

[0043] In the above formula (A), SP １ and SP ２Examples of the divalent aliphatic hydrocarbon group having 1 to 20 carbon atoms represented by one embodiment of the formula (1) include a linear or branched alkylene group having 1 to 20 carbon atoms, a linear or branched alkenylene group having 1 to 20 carbon atoms, and a linear or branched alkynylene group having 1 to 20 carbon atoms. As the linear or branched alkylene group having 1 to 20 carbon atoms, an alkylene group having 1 to 12 carbon atoms is preferred, and an alkylene group having 1 to 10 carbon atoms is more preferred, and suitable examples include a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, and a hexylene group. As the linear or branched alkenylene group having 1 to 20 carbon atoms, an alkenylene group having 2 to 10 carbon atoms is preferred, and an alkenylene group having 2 to 4 carbon atoms is more preferred, and suitable examples include an ethenylene group. As the linear or branched alkynylene group having 1 to 20 carbon atoms, an alkynylene group having 2 to 10 carbon atoms is preferred, an alkynylene group having 2 to 4 carbon atoms is more preferred, and a suitable example is an ethynylene group. As described above, -CH ２ One or more of - may be substituted with -O-, -S-, -NH-, -N(Q)-, or -CO-. Examples of the substituent represented by Q include the substituents described in the above-mentioned substituent group A. Among them, an alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group, or a halogen atom is preferable.

[0044] In the above formula (A), L １ and L ２Examples of the monovalent organic group represented by include the substituents described in the above-mentioned Substituent Group A, and among these, alkyl groups, aryl groups, heteroaryl groups, alkoxy groups, cyano groups, and carboxy groups are preferred. The alkyl group may be linear, branched, or cyclic, but linear groups are preferred. The alkyl group preferably has 1 to 30 carbon atoms, more preferably 1 to 20, and even more preferably 1 to 10. The aryl group may be monocyclic or polycyclic, but monocyclic groups are preferred. The aryl group preferably has 6 to 25 carbon atoms, more preferably 6 to 10. The heteroaryl group may be monocyclic or polycyclic. The number of heteroatoms constituting the heteroaryl group is preferably 1 to 3. The heteroatoms constituting the heteroaryl group are preferably nitrogen atoms, sulfur atoms, or oxygen atoms. The heteroaryl group preferably has 6 to 18 carbon atoms, more preferably 6 to 12. The alkyl group, aryl group, and heteroaryl group may be unsubstituted or may have a substituent. Examples of the substituent include the substituents described in the above-mentioned substituent group A, and among them, an alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group, or a halogen atom is preferable. １ and L ２ The polymerizable group represented by at least one of the formulae (P-1) to (P-20) is preferably a polymerizable group represented by any one of the formulae (P-1) to (P-20) above.

[0045] In the formula (A), Ar represents any one of aromatic rings selected from the group consisting of groups represented by the following formulae (Ar-1) to (Ar-7), as described above. In the following formulae (Ar-1) to (Ar-7), * represents D in the formula (A). １ or D ２ represents the bonding position with

[0046] In the above formula (Ar-1), Q １ represents N or CH, and Q ２ is -S-, -O-, or -N(R ６ )-, R ６ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; Y １represents an aromatic hydrocarbon group having 6 to 12 carbon atoms which may have a substituent, an aromatic heterocyclic group having 3 to 12 carbon atoms which may have a substituent, or an alicyclic hydrocarbon group having 6 to 20 carbon atoms which may have a substituent, and -CH ２ One or more of - may be replaced by -O-, -S- or -NH-. ６ Specific examples of the alkyl group having 1 to 6 carbon atoms represented by one embodiment of the formula (1) 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. １ Examples of the aromatic hydrocarbon group having 6 to 12 carbon atoms represented by one embodiment of the formula (I) include aryl groups such as a phenyl group, a 2,6-diethylphenyl group, and a naphthyl group. １ Examples of the aromatic heterocyclic group having 3 to 12 carbon atoms represented by one embodiment of the formula (1) include heteroaryl groups such as a thienyl group, a thiazolyl group, a furyl group, a pyridyl group, a benzofuryl group, and a benzothiazolyl group; and groups formed by removing one hydrogen atom from an indole ring, a benzofuran ring, a benzothiophene ring, a benzimidazole ring, a benzothiazole ring, or a benzoxazole ring. １ The aromatic heterocyclic group having 3 to 12 carbon atoms represented by Y is preferably a group obtained by removing one hydrogen atom from a benzofuran ring or a benzothiazole ring. １ Examples of the alicyclic hydrocarbon group having 6 to 20 carbon atoms represented by one embodiment of the formula (1) include a cyclohexylene group, a cyclopentylene group, a norbornylene group, and an adamantylene group. １ Examples of the substituent that may be possessed by the group include the substituents described in the above-mentioned substituent group A, and among them, an alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group, a nitro group, a cyano group, or a halogen atom is preferable.

[0047] In addition, in the above formulas (Ar-1) to (Ar-7), Z １ , Z ２ and Z ３each independently represents a hydrogen atom, a monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms, a monovalent aromatic heterocyclic group having 6 to 20 carbon atoms, a halogen atom, a cyano group, a nitro group, -OR ７ , -NR ８ R ９ , -SR １０ , -COOR １１ , or -COR １２ represents R ７ ~R １２ each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; Z １ and Z ２ may be bonded to each other to form an aromatic ring. As the monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, an alkyl group having 1 to 15 carbon atoms is preferred, an alkyl group having 1 to 8 carbon atoms is more preferred, specifically, a methyl group, an ethyl group, an isopropyl group, a tert-pentyl group (1,1-dimethylpropyl group), a tert-butyl group, or a 1,1-dimethyl-3,3-dimethyl-butyl group is further preferred, and a methyl group, an ethyl group, or a tert-butyl group is particularly preferred. Examples of the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms include monocyclic saturated hydrocarbon groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclodecyl, methylcyclohexyl, and ethylcyclohexyl groups; monocyclic unsaturated hydrocarbon groups such as cyclobutenyl, cyclopentenyl, cyclohexenyl, cycloheptenyl, cyclooctenyl, cyclodecenyl, cyclopentadienyl, cyclohexadienyl, cyclooctadienyl, and cyclodecadiene; bicyclo[2.2.1]heptyl, bicyclo[2.2.2]octyl, and tricyclo[5.2.1.0]diene; ２，６ ] decyl group, tricyclo[3.3.1.1 ３，７ ]decyl group, tetracyclo[6.2.1.1 ３，６ .0 ２，７] dodecyl group, adamantyl group, and other polycyclic saturated hydrocarbon groups. Specific examples of the monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms include a phenyl group, a 2,6-diethylphenyl group, a naphthyl group, and a biphenyl group, with an aryl group having 6 to 12 carbon atoms (particularly a phenyl group) being preferred. Specific examples of the monovalent aromatic heterocyclic group having 6 to 20 carbon atoms include a 4-pyridyl group, a 2-furyl group, a 2-thienyl group, a 2-pyrimidinyl group, and a 2-benzothiazolyl group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a fluorine atom, a chlorine atom, and a bromine atom being preferred. On the other hand, R ７ ~R １０ Specific examples of the alkyl group having 1 to 6 carbon atoms 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.

[0048] Z １ and Z ２ As described above, may be bonded to each other to form an aromatic ring. For example, Z １ and Z ２ Examples of the structure in which the groups bond to each other to form an aromatic ring include a group represented by the following formula (Ar-1a): In the following formula (Ar-1a), * represents D in the above formula (A). １ or D ２ represents the bonding position with In the above formula (Ar-1a), Q １ , Q ２ and Y １ The examples of the alkyl group include those described above in relation to formula (Ar-1).

[0049] In addition, in the above formulas (Ar-2) and (Ar-3), A ３ and A ４ are each independently —O—, —N(R １３ represents a group selected from the group consisting of —, —S—, and —CO—; R １３ represents a hydrogen atom or a substituent.１３ Examples of the substituent represented by one embodiment of the formula (I) include the substituents described in the above-mentioned Substituent Group A, and among them, an alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group, or a halogen atom is preferable.

[0050] In the formula (Ar-2), X represents a nonmetallic atom of Groups 14 to 16. However, the nonmetallic atom may have a hydrogen atom or a substituent bonded thereto. Examples of the nonmetallic atom of Groups 14 to 16 represented by X include an oxygen atom, a sulfur atom, a hydrogen atom, or a nitrogen atom bonded to a substituent [=N-R Ｎ１ , R Ｎ１ represents a hydrogen atom or a substituent.], a carbon atom to which a hydrogen atom or a substituent is bonded [═C—(R Ｃ１ ) ２ , R Ｃ１ represents a hydrogen atom or a substituent.] Examples of the substituent include the substituents described in the above-mentioned substituent group A, and among them, preferred examples include an alkyl group, an alkoxy group, an alkyl-substituted alkoxy group, a cyclic alkyl group, an aryl group (for example, a phenyl group, a naphthyl group, etc.), a cyano group, an amino group, a nitro group, an alkylcarbonyl group, a sulfo group, and a hydroxyl group.

[0051] In addition, in the above formula (Ar-3), D ７ and D ８ each independently represents a single bond, or —CO—, —O—, —S—, —C(═S)—, or —CR １ R ２ -, -CR ３ =CR ４ -, -NR ５ -, or a divalent linking group formed by a combination of two or more thereof, R １ ~R ５ each independently represents a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 12 carbon atoms. Here, the divalent linking group is D in the above formula (A). １ , D ２ , D ３ , D ４ , D ５ and D ６ Examples of the above-described examples are the same as those described above.

[0052] In addition, in the above formula (Ar-3), SP ３ and SP ４ each independently represents a single bond or a divalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, provided that —CH ２ One or more of - may be substituted with -O-, -S-, -NH-, -N(Q)- or -CO-. Q represents a substituent. Examples of the substituent represented by Q include the substituents described in the above-mentioned substituent group A, and among these, an alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group, or a halogen atom is preferred. Here, the divalent aliphatic hydrocarbon group is a group represented by the formula (A) above, １ and SP ２ Examples of the above-described examples are the same as those described above.

[0053] In addition, in the above formula (Ar-3), L ３ and L ４ Each independently represents a monovalent organic group. Here, examples of the monovalent organic group include L １ and L ２ Examples of the above-described examples are the same as those described above.

[0054] In the above formulae (Ar-4) to (Ar-7), 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. In the above formulae (Ar-4) to (Ar-7), Ay represents a hydrogen atom, an alkyl group having 1 to 12 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. Here, the aromatic rings in Ax and Ay may have a substituent, and Ax and Ay may be bonded to form a ring. In addition, Q ３ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms which may have a substituent. Examples of Ax and Ay include those described in paragraphs

[0039] to

[0095] of WO 2014 / 010325. ３Specific examples of the alkyl group having 1 to 6 carbon atoms represented by 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. Examples of the substituent include the substituents described in the above-mentioned substituent group A. Among these, an alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group, or a halogen atom is preferred.

[0055] Examples of the liquid crystal compound include compounds represented by the general formula (1) described in JP-A-2010-084032 (particularly, compounds described in paragraphs

[0067] to

[0073] ), compounds represented by the general formula (II) described in JP-A-2016-053709 (particularly, compounds described in paragraphs

[0036] to

[0043] ), and compounds represented by the general formula (1) described in JP-A-2016-081035 (particularly, compounds described in paragraphs

[0043] to

[0055] ), and compounds described in paragraphs

[0025] to

[0056] of WO 2021 / 060427.

[0056] The content of the liquid crystal compound is preferably 50 to 99 mass %, more preferably 60 to 99 mass %, based on the total solid content of the liquid crystal composition, where the total solid content of the liquid crystal composition means the total mass of components excluding the solvent.

[0057] (Other Polymerizable Compounds) The liquid crystal composition may contain other polymerizable compounds in addition to the above-described liquid crystal compounds. The other polymerizable compounds may or may not have liquid crystallinity. Therefore, among the other polymerizable compounds, other polymerizable compounds having liquid crystallinity can be classified as the above-described liquid crystal compounds. Here, the polymerizable group contained in the other polymerizable compound is not particularly limited, and suitable examples thereof include polymerizable groups represented by any of the above-described formulas (P-1) to (P-20).

[0058] The other polymerizable compound is preferably another polymerizable compound having 2 to 4 polymerizable groups, and more preferably another polymerizable compound having 2 polymerizable groups, because this further improves the durability of the liquid crystal layer that is formed.

[0059] Specific examples of other polymerizable compounds include compounds having liquid crystallinity represented by formulas (M1), (M2), and (M3) described in paragraphs

[0030] to

[0033] of JP 2014-077068 A, more specifically, specific examples described in paragraphs

[0046] to

[0055] of the same publication. Furthermore, examples of compounds not having liquid crystallinity include polyfunctional acrylates such as polyethylene glycol diacrylate.

[0060] The content of the other polymerizable compound is preferably 0 to 80 parts by mass, more preferably 0 to 70 parts by mass, relative to 100 parts by mass of the liquid crystal compound. The other polymerizable compound may be used alone or in combination of two or more kinds.

[0061] (Boronic Acid Monomer) The liquid crystal composition preferably contains a boronic acid monomer having a polymerizable group and a boronic acid group represented by the following formula (B), for the reasons that the adhesion between the support and the liquid crystal layer is improved and the diagonal contrast of the liquid crystal display device is improved. Here, the polymerizable group contained in the boronic acid monomer is not particularly limited, and suitable examples include polymerizable groups represented by any of the above-mentioned formulas (P-1) to (P-20). The number of boronic acid groups represented by the following formula (B) contained in the boronic acid monomer is not particularly limited, and may be one or multiple (two or more).

[0062] In the above formula (B), * represents a bonding position. １ and R ２ each independently represents a hydrogen atom, an optionally substituted aliphatic hydrocarbon group, an optionally substituted aryl group, or an optionally substituted heterocyclic group; R １ and R ２ may be linked to each other to form a ring.

[0063] R １ and R ２Examples of the aliphatic hydrocarbon group represented by one embodiment of R include substituted or unsubstituted linear or branched alkyl groups having 1 to 20 carbon atoms (e.g., methyl, ethyl, isopropyl, etc.), substituted or unsubstituted cyclic alkyl groups having 3 to 20 carbon atoms (e.g., cyclohexyl, etc.), and alkenyl groups having 2 to 20 carbon atoms (e.g., vinyl, etc.). １ and R ２ Examples of the aryl group represented by one embodiment of R include a substituted or unsubstituted phenyl group having 6 to 20 carbon atoms (e.g., a phenyl group, a tolyl group, etc.), and a substituted or unsubstituted naphthyl group having 10 to 20 carbon atoms. １ and R ２ Examples of the heterocyclic group represented by one embodiment of R include a substituted or unsubstituted 5- or 6-membered ring group containing at least one heteroatom (e.g., a nitrogen atom, an oxygen atom, a sulfur atom, etc.), and examples thereof include a pyridyl group, an imidazolyl group, a furyl group, a piperidyl group, and a morpholino group. 1 and R 2 may be linked together to form a ring, for example, R 1 and R 2 may be linked to form a 4,4,5,5-tetramethyl-1,3,2-dioxaborolane ring. Examples of the substituents that these aliphatic hydrocarbon groups, aryl groups, and heterocyclic groups may have include the substituents described in the above-mentioned substituent group A.

[0064] In the above formula (B), R １ and R ２ is a hydrogen atom, a linear or branched alkyl group having 1 to 3 carbon atoms, or R １ and R ２ are preferably linked to form a ring, and more preferably are hydrogen atoms.

[0065] The molecular weight of the boronic acid monomer is not particularly limited, but is preferably 120 to 1,200, more preferably 180 to 800, in terms of excellent compatibility with polyfunctional monomers.

[0066] A preferred embodiment of the boronic acid monomer is a boronic acid monomer represented by the following formula (B-1), which has better adhesion between the polarizer and the resin layer.

[0067]

[0068] R in formula (B-1) 1 and R 2 is as defined above. Z represents a polymerizable group. The polymerizable group is as defined above. X 1 represents a single bond or a divalent linking group. Examples of the divalent linking group include -O-, -CO-, -NH-, -CO-NH-, -COO-, -O-COO-, alkylene groups, arylene groups, heterocyclic groups (heteroaryl groups), and divalent linking groups selected from combinations thereof. Examples of combinations include -arylene group-COO-arylene group-O-alkylene group-, -arylene group-COO-alkylene group-, etc.

[0069] Specific examples of the boronic acid monomer are shown below, but the present invention is not limited thereto.

[0070]

[0071]

[0072]

[0073]

[0074] When the liquid crystal composition contains a boronic acid monomer, the content of the boronic acid monomer is preferably 1 to 10 mass %, more preferably 1 to 9 mass %, and even more preferably 2 to 8 mass %, based on the total solid content of the liquid crystal composition.

[0075] (Solvent) The liquid crystal composition preferably contains a solvent from the viewpoint of workability in forming a retardation film, etc. The solvent is preferably an organic solvent, and specific examples thereof include ketones (e.g., acetone, 2-butanone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, cyclopentanone, etc.), ethers (e.g., dioxane, tetrahydrofuran, etc.), aliphatic hydrocarbons (e.g., hexane, etc.), alicyclic hydrocarbons (e.g., cyclohexane, etc.), aromatic hydrocarbons (e.g., toluene, xylene, trimethylbenzene, etc.), halogenated carbons (e.g., dichloromethane, dichloroethane, dichlorobenzene, chlorotoluene, etc.), esters (e.g., acetic acid, Examples of suitable solvents include methyl, ethyl acetate, and butyl acetate), water, alcohols (e.g., methanol, ethanol, isopropanol, butanol, and cyclohexanol), cellosolves (e.g., methyl cellosolve, ethyl cellosolve, and propylene glycol monomethyl ether), cellosolve acetates (e.g., propylene glycol monomethyl ether acetate), sulfoxides (e.g., dimethyl sulfoxide), and amides (e.g., dimethylformamide and dimethylacetamide). These may be used alone or in combination of two or more.

[0076] The content of the solvent is preferably 55 to 85% by mass, more preferably 60 to 80% by mass, based on the total mass of the liquid crystal composition, from the viewpoint of improving the coatability of the liquid crystal composition. When two or more solvents are contained, the total amount is preferably within the above range.

[0077] (Other Components) The liquid crystal composition may contain other components in addition to those described above, such as a polymerization initiator, a leveling agent, a surfactant, a tilt control agent, an alignment aid, a plasticizer, and a crosslinking agent.

[0078] [Polarizing Plate] The polarizing plate of the present invention is a polarizing plate having the above-mentioned retardation film of the present invention and a polarizer. In the polarizing plate of the present invention, the polarizer, the liquid crystal layer of the retardation film, and the support of the retardation film are preferably arranged in this order.

[0079] [Polarizer] The polarizer of the polarizing plate of the present invention is not particularly limited as long as it has the function of converting light into specific linearly polarized light, and conventionally known absorptive polarizers and reflective polarizers can be used. Examples of absorptive polarizers include iodine-based polarizers, dye-based polarizers using dichroic dyes, and polyene-based polarizers. Iodine-based polarizers and dye-based polarizers include coated polarizers and stretched polarizers, and either type can be used. However, polarizers produced by adsorbing iodine or a dichroic dye onto polyvinyl alcohol and stretching the resulting film are preferred. Furthermore, methods for obtaining polarizers by stretching and dyeing a laminated film having a polyvinyl alcohol layer formed on a substrate are described in Japanese Patent Nos. 5,048,120, 5,143,918, 4,691,205, 4,751,481, and 4,751,486. These known techniques related to polarizers can also be preferably used. As the reflective polarizer, a polarizer in which thin films with different birefringence are laminated, a wire grid polarizer, a polarizer in which a cholesteric liquid crystal having a selective reflection region is combined with a quarter-wave plate, etc. are used. Among them, a polyvinyl alcohol-based resin (-CH ２ A polymer containing —CHOH— as a repeating unit, particularly at least one selected from the group consisting of polyvinyl alcohol and an ethylene-vinyl alcohol copolymer, is preferred.

[0080] In the present invention, the thickness of the polarizer is not particularly limited, but is preferably 5 to 40 μm, more preferably 5 to 30 μm, and even more preferably 5 to 20 μm. The above thickness allows for the reduction in thickness of display devices.

[0081] In the polarizing plate of the present invention, the retardation film is preferably arranged so that the slow axis of the support thereof is perpendicular to or parallel to the absorption axis of the polarizer, and more preferably so that the slow axis is parallel to the absorption axis of the polarizer.

[0082] [Polarizer Protective Film] The polarizing plate of the present invention may have a polarizer protective film disposed on the surface of the polarizer. The polarizer protective film may be disposed on only one side of the polarizer (the surface opposite the retardation film side) or on both sides of the polarizer. The configuration of the polarizer protective film is not particularly limited, and may be, for example, a so-called transparent support or hard coat layer, or a laminate of a transparent support and a hard coat layer. The hard coat layer may be a known layer, for example, a layer obtained by polymerizing and curing a polyfunctional monomer. The transparent support may also be a known transparent support. For example, materials for forming the transparent support may include cellulose-based polymers (hereinafter referred to as cellulose acylate), such as triacetyl cellulose, thermoplastic norbornene-based resins (such as Zeonex and Zeonor manufactured by Zeon Corporation and Arton manufactured by JSR Corporation), acrylic resins, and polyester resins. The thickness of the polarizer protective film is not particularly limited, but is preferably 50 μm or less, for reasons such as enabling the thickness of the polarizing plate to be thin.

[0083] [Adhesive Layer] The polarizing plate of the present invention may have an adhesive layer disposed between the retardation film (particularly the liquid crystal layer) and the polarizer. The adhesive layer used for laminating the retardation film and the polarizer refers to, for example, a substance having a ratio of storage modulus G' to loss modulus G" (tan δ = G" / G') measured with a dynamic viscoelasticity measuring device of 0.001 to 1.5, and includes so-called adhesives and substances that tend to creep. Adhesives that can be used in the present invention include, but are not limited to, polyvinyl alcohol-based adhesives.

[0084] [Liquid Crystal Display Device] The liquid crystal display device of the present invention is a liquid crystal display device having the polarizing plate of the present invention described above. Specifically, the liquid crystal display device of the present invention is a liquid crystal display device having the polarizing plate of the present invention described above and a lateral electric field mode liquid crystal cell, and is preferably a liquid crystal display device in which, from the viewing side, the polarizer of the polarizing plate, the liquid crystal layer of the polarizing plate, the support of the polarizing plate, and the liquid crystal cell are arranged in this order. The liquid crystal cell constituting the liquid crystal display device will be described in detail below.

[0085] [Liquid Crystal Cell] The liquid crystal cell used in the liquid crystal display device of the present invention is preferably an in-plane switching (IPS) liquid crystal cell. The liquid crystal cell used in the liquid crystal display device is preferably, but not limited to, a vertical alignment (VA) mode, optically compensated bend (OCB) mode, in-plane switching (IPS) mode, fringe-field switching (FFS) mode, or twisted nematic (TN) mode. In a TN mode liquid crystal cell, rod-shaped liquid crystal molecules are aligned substantially horizontally when no voltage is applied, and are further twisted at an angle of 60 to 120°. TN mode liquid crystal cells are most commonly used in color TFT liquid crystal displays and are described in numerous literature. In a VA mode liquid crystal cell, rod-shaped liquid crystal molecules are aligned substantially vertically when no voltage is applied. VA mode liquid crystal cells include (1) narrowly defined VA mode liquid crystal cells in which rod-shaped liquid crystal molecules are aligned substantially vertically when no voltage is applied and substantially horizontally when a voltage is applied (described in Japanese Patent Application Laid-Open No. 2-176625), (2) multi-domain VA mode liquid crystal cells (described in SID97, Digest of tech. Papers (Proceedings) 28 (1997) 845) in order to widen the viewing angle (MVA mode liquid crystal cells), (3) n-ASM mode liquid crystal cells in which rod-shaped liquid crystal molecules are aligned substantially vertically when no voltage is applied and substantially horizontally when a voltage is applied (described in Proceedings of the Japan Liquid Crystal Symposium 58-59 (1998)), and (4) SURVIVAL mode liquid crystal cells (announced at LCD International 98). Furthermore, VA mode liquid crystal cells may be any of PVA (Patterned Vertical Alignment) type, optical alignment type, and PSA (Polymer-Sustained Alignment) type. Details of these modes are described in Japanese Patent Laid-Open No. 2006-215326 and Japanese Patent Laid-Open No. 2008-538819. In IPS mode liquid crystal cells, rod-shaped liquid crystal molecules are aligned substantially parallel to the substrates, and when an electric field parallel to the substrate surfaces is applied, the liquid crystal molecules respond in a planar manner.In the IPS mode, black display is achieved when no electric field is applied, and the absorption axes of the pair of upper and lower polarizing plates are perpendicular to each other. Methods of using an optical compensation sheet to reduce light leakage during black display in an oblique direction and improve the viewing angle are disclosed in JP-A Nos. 10-54982, 11-202323, 9-292522, 11-133408, 11-305217, and 10-307291.

[0086] The present invention will be described in more detail below with reference to examples. The materials, amounts used, ratios, treatment contents, treatment procedures, etc. shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the examples shown below.

[0087] [Example 1] [Preparation of Retardation Film] A commercially available polycarbonate film (PureAce RM-147, Re(550)=146 nm, Rth(550)=111 nm, manufactured by Teijin Limited) that had been subjected to a biaxial stretching treatment was prepared as a support for a retardation film. Liquid crystal composition 1 prepared according to the following composition was applied to one side of the support without surface treatment using a die coater. Subsequently, the liquid crystal composition 1 was heated with hot air at 60°C for 60 seconds to dry the solvent and ripen the liquid crystal compound. Under a nitrogen purge, the film was irradiated with ultraviolet light (300 mJ / cm) at an oxygen concentration of 100 ppm at 25°C. ２ ) was carried out to fix the alignment of the liquid crystal compound, thereby forming a liquid crystal layer, and producing the retardation film of Example 1. The optical properties of the liquid crystal layer were estimated from the change in optical properties before and after coating, and as a result, the optical properties of the liquid crystal layer were Re(550) = 0 nm, Rth(550) = -120 nm, and Rth(450) / Rth(550) = 0.93.

[0088] Liquid crystal composition 1 -------------------------------- 28.0 parts by mass of liquid crystal compound R1 shown below 10.0 parts by mass of liquid crystal compound R2 shown below 54.0 parts by mass of liquid crystal compound R3 shown below 8.0 parts by mass of liquid crystal compound R4 shown below 4.5 parts by mass of boronic acid monomer B1 shown below 8.0 parts by mass of NK ester A-600 (manufactured by Shin-Nakamura Chemical Co., Ltd.) 1.5 parts by mass of photopolymerization initiator S1 shown below 0.4 parts by mass of surfactant P1 shown below 0.5 parts by mass of surfactant P2 shown below Acetone 200.0 parts by mass Propylene glycol monomethyl ether acetate 69.0 parts by mass Methanol 8.0 parts by mass

[0089] Liquid crystal compound R1 (a mixture of the following liquid crystal compounds (RA), (RB), and (RC) in a mass ratio of 83:15:2. Me in the following liquid crystal compounds (RB) and (RC) represents a methyl group.)

[0090] Liquid crystal compound R2 (In the following formula, the group adjacent to the acryloyloxy group represents a propylene group (a group in which a methyl group is substituted with an ethylene group), and therefore liquid crystal compound R2 represents a mixture of positional isomers in which the position of the methyl group differs.)

[0091] Liquid crystal compound R3 (In the following formula, the group adjacent to the acryloyloxy group represents a propylene group (a group in which a methyl group is substituted with an ethylene group), and therefore liquid crystal compound R3 represents a mixture of positional isomers in which the position of the methyl group differs.)

[0092] Liquid crystal compound R4

[0093] Boronic Acid Monomer B1

[0094] Polymerization initiator S1

[0095] Surfactant P1 (weight average molecular weight: 15,000; in the following formula, the numbers in parentheses for the repeating units represent mass %.)

[0096] Surfactant P2 (weight average molecular weight: 11,200; in the following formula, the numbers in parentheses for the repeating units represent mass %.)

[0097] [Preparation of Protective Film 1] The following composition was charged into a mixing tank and stirred to prepare core layer cellulose acylate dope 1. Core layer cellulose acylate dope 1 ------------------------------------------------- Cellulose acetate having an acetyl substitution degree of 2.88: 100 parts by mass Ester oligomer A described below: 10 parts by mass Polarizer durability improver described below: 4 parts by mass Ultraviolet absorber described below: 430 parts by mass Methylene chloride (first solvent): 64 parts by mass Methanol (second solvent): 64 parts by mass

[0098] Ester Oligomer A (weight average molecular weight: 750)

[0099] Polarizer durability improver

[0100] UV absorbers

[0101] To 90 parts by mass of the above core layer cellulose acylate dope 1, 10 parts by mass of the following matting agent solution was added, to prepare outer layer cellulose acylate dope 1. Outer layer cellulose acylate dope 1 ---------------------------------------------------------------- - Silica particles having an average particle size of 20 nm (AEROSIL R972, manufactured by Nippon Aerosil Co., Ltd.) 2 parts by mass - Methylene chloride (first solvent) 76 parts by mass - Methanol (second solvent) 11 parts by mass - Core layer cellulose acylate dope 1 ----------------------------------------------------------------

[0102] The core layer cellulose acylate dope 1 and outer layer cellulose acylate dope 1 on both sides were simultaneously cast onto a drum at 20°C from a casting nozzle. The film was peeled off when the solvent content was approximately 20% by mass, and both ends of the film in the width direction were fixed with tenter clips. The film was then stretched 1.1 times laterally while drying while the residual solvent content was 3 to 15%. The resulting film was then transported between the rolls of a heat treatment device and further dried to produce a 40 μm-thick cellulose acylate film 1, which was used as protective film 1. The retardation of protective film 1 was measured, revealing Re(550) = 2 nm and Rth(550) = 7 nm.

[0103] [Preparation of Protective Film 2] The following composition was charged into a mixing tank and stirred to prepare core layer cellulose acylate dope 2. Core layer cellulose acylate dope 2: 100 parts by mass of cellulose acetate having an acetyl substitution degree of 2.88, 12 parts by mass of the following polyester, 4 parts by mass of the above polarizer durability improver, 430 parts by mass of methylene chloride (first solvent), 64 parts by mass of methanol (second solvent).

[0104] Polyester (number average molecular weight: 800)

[0105] To 90 parts by mass of the above core layer cellulose acylate dope 2, 10 parts by mass of the following matting agent solution was added, to prepare outer layer cellulose acylate dope 2. ---------------------------------------------------------------- Matting agent solution ---------------------------------------------------------------- Silica particles having an average particle size of 20 nm (AEROSIL R972, manufactured by Nippon Aerosil Co., Ltd.) 2 parts by mass Methylene chloride (first solvent) 76 parts by mass Methanol (second solvent) 11 parts by mass Core layer cellulose acylate dope 1 part by mass

[0106] The core layer cellulose acylate dope 2 and the outer layer cellulose acylate dope 2 were filtered through a filter paper with an average pore size of 34 μm and a sintered metal filter with an average pore size of 10 μm. The core layer cellulose acylate dope 2 and the outer layer cellulose acylate dope 2 on both sides were simultaneously cast onto a drum at 20°C from a casting nozzle (band caster). The film, with a solvent content of approximately 20% by mass, was then peeled off, and both ends of the film in the width direction were fixed with tenter clips. It was then stretched transversely at a stretch ratio of 1.1 times while being dried. The resulting film was then transported between the rolls of a heat treatment device and further dried to produce a 40 μm-thick cellulose acylate film 2, which was used as protective film 2. The retardation of protective film 2 was measured, revealing Re(550) = 1 nm and Rth(550) = -5 nm.

[0107] [Saponification Treatment of Protective Film] The protective films 1 and 2 prepared above were immersed in a 2.3 mol / L aqueous sodium hydroxide solution at 55° C. for 3 minutes. Thereafter, they were washed in a water washing bath at room temperature and neutralized with 0.05 mol / L sulfuric acid at 30° C. They were washed again in a water washing bath at room temperature and further dried with hot air at 100° C., thereby saponifying the protective film surface.

[0108] [Preparation of Polarizing Plate] The saponified protective film 1, polyvinyl alcohol-based polarizer, and retardation film prepared above were bonded together using an adhesive so that the absorption axis of the polarizer and the slow axis of the retardation film were parallel to each other and the liquid crystal layer side of the retardation film faced the polarizer, thereby preparing a first polarizing plate of Example 1. A 3% aqueous solution of PVA (PVA-117H, manufactured by Kuraray Co., Ltd.) was used as the adhesive. The adhesive strength between the polarizer and the retardation film in the first polarizing plate was sufficient for practical use. A second polarizing plate was prepared by similarly bonding the saponified protective film 1, polyvinyl alcohol-based polarizer, and saponified protective film 2.

[0109] [Fabrication of Liquid Crystal Display Device] A commercially available liquid crystal display device (iPad (registered trademark), manufactured by Apple Inc.) was disassembled, and the attached polarizing plates on both sides were peeled off. The first polarizing plate was attached to the viewing side and the second polarizing plate was attached to the backlight side using an adhesive (SK2057 manufactured by Soken Kagaku Co., Ltd.), thereby fabricating the liquid crystal display device of Example 1. In this case, the first polarizing plate was attached so that the retardation film was on the liquid crystal cell side, and the second polarizing plate was attached so that the protective film 2 was on the liquid crystal cell side. In addition, the first polarizing plate and the second polarizing plate were attached so that the slow axis of the liquid crystal in the cell and the absorption axis of the first polarizing plate were perpendicular to each other, and the slow axis of the liquid crystal in the cell and the absorption axis of the second polarizing plate were parallel to each other.

[0110] Example 2 Before applying the liquid crystal composition 1, a discharge amount of 100 W·min / m was applied to the surface of the support on the side where the liquid crystal composition 1 was to be applied. ２ A retardation film of Example 2 was produced in the same manner as in Example 1, except that a corona treatment was performed at 1000 kJ / cm2. The optical properties of the liquid crystal layer were Re(550) = 0 nm, Rth(550) = -122 nm, and Rth(450) / Rth(550) = 0.93. Next, a polarizing plate and a liquid crystal display device were produced in the same manner as in Example 1, except that the retardation film produced in Example 2 was used.

[0111] [Example 3] A retardation film of Example 3 was produced in the same manner as in Example 2, except that the following liquid crystal composition 2 was used instead of liquid crystal composition 1. The optical properties of the liquid crystal layer were Re(550) = 0 nm, Rth(550) = -118 nm, and Rth(450) / Rth(550) = 0.93. Next, a polarizing plate and a liquid crystal display device were produced in the same manner as in Example 1, except that the retardation film produced in Example 3 was used.

[0112] Liquid Crystal Composition 2 - 28.0 parts by mass of the liquid crystal compound R1 - 10.0 parts by mass of the liquid crystal compound R2 - 54.0 parts by mass of the liquid crystal compound R3 - 8.0 parts by mass of the liquid crystal compound R4 - 8.0 parts by mass of NK Ester A-600 (manufactured by Shin-Nakamura Chemical Co., Ltd.) - 1.5 parts by mass of the polymerization initiator S1 - 0.4 parts by mass of the surfactant P1 - 0.5 parts by mass of the surfactant P2 - 200.0 parts by mass of acetone - 69.0 parts by mass of propylene glycol monomethyl ether acetate - 8.0 parts by mass of methanol.

[0113] [Example 4] Polycarbonate film RM-147 was dissolved in methylene chloride to prepare a dope with a solids concentration of 19 wt %. A cast film was prepared from this dope solution by a known method. The obtained film was uniaxially stretched at 160°C to prepare a stretched film 1 with a thickness of 55 μm. The stretched film 1 had Re(550) = 134 nm and Rth(550) = 67 nm, and was a positive A plate. A retardation film of Example 4 was prepared in the same manner as in Example 2, except that this stretched film 1 was used as the support. The optical properties of the liquid crystal layer were Re(550) = 0 nm, Rth(550) = -104 nm, and Rth(450) / Rth(550) = 0.93. Next, a polarizing plate and a liquid crystal display device were prepared in the same manner as in Example 1, except that the retardation film prepared in Example 4 was used.

[0114] [Example 5] A retardation film of Example 5 was produced in the same manner as in Example 4, except that the following liquid crystal composition 3 was used instead of liquid crystal composition 1. The optical properties of the liquid crystal layer were Re(550) = 0 nm, Rth(550) = -105 nm, and Rth(450) / Rth(550) = 1.07. Next, a polarizing plate and a liquid crystal display device were produced in the same manner as in Example 1, except that the retardation film produced in Example 5 was used.

[0115] ------------------------------------------------ Liquid Crystal Composition 3---------------------------------------------------------------- Liquid crystal compound R1 described above 100.0 parts by mass Boronic acid monomer B1 described above 4.5 parts by mass Alignment aid A1 described below 2.0 parts by mass A-TMMT (manufactured by Shin-Nakamura Chemical Co., Ltd.) 8.0 parts by mass Photopolymerization initiator S2 described below 5.0 parts by mass Photopolymerization initiator S3 described below 2.0 parts by mass Surfactant P1 described above 0.4 parts by mass Surfactant P2 described above 0.5 parts by mass Acetone 353.0 parts by mass Propylene glycol monomethyl ether acetate 122.0 parts by mass Methanol 15.0 parts by mass

[0116] Orientation Aid A1

[0117] Photopolymerization initiator S2

[0118] Photopolymerization initiator S3

[0119] [Comparative Example 1] An optical film of Comparative Example 1 was produced by the method described in Example 1 of JP 2016-206236 A. The optical properties of the liquid crystal layer were Re(550) = 0 nm and Rth(550) = -119 nm. Next, a polarizing plate and a liquid crystal display device were produced in the same manner as in Example 1, except that the retardation film produced in Comparative Example 1 was used.

[0120] [Comparative Example 2] A retardation film of Comparative Example 2 was produced in the same manner as in Example 1, except that the following liquid crystal composition 4 was used instead of liquid crystal composition 1. The optical properties of the liquid crystal layer were Re(550) = 0 nm and Rth(550) = -120 nm. Next, a polarizing plate and a liquid crystal display device were produced in the same manner as in Example 1, except that the retardation film produced in Comparative Example 2 was used.

[0121] Liquid Crystal Composition 4 - 28.0 parts by mass of the liquid crystal compound R1 - 10.0 parts by mass of the liquid crystal compound R2 - 54.0 parts by mass of the liquid crystal compound R3 - 8.0 parts by mass of the liquid crystal compound R4 - 4.5 parts by mass of the boronic acid monomer B1 - 8.0 parts by mass of NK Ester A-600 (manufactured by Shin-Nakamura Chemical Co., Ltd.) - 1.5 parts by mass of the polymerization initiator S1 - 0.4 parts by mass of the surfactant P1 - 0.5 parts by mass of the surfactant P2 - 277.0 parts by mass of methyl isobutyl ketone -

[0122] [Comparative Example 3] A retardation film of Comparative Example 3 was produced in the same manner as in Example 1, except that the polycarbonate film described in Example 1 of Patent Document 1 (WO 2020 / 045224) was used as the support of the retardation film. The optical properties of the liquid crystal layer were Re(550) = 0 nm, Rth(550) = -107 nm.

[0123] [Surface Energy] The surface energy of the support of the retardation film prepared in Examples and Comparative Examples on the surface on which the liquid crystal layer is formed, and the non-polar component and polar component contained in the surface energy were measured by the above-mentioned method. The results are shown in Table 1 below.

[0124] [Fat Width at Half Maximum of Power Spectrum Peak] The half width at half maximum of the power spectrum peak of the retardation films prepared in Examples and Comparative Examples was measured by the method described above. The results are shown in Table 1 below.

[0125] [Haze Value] The haze values ​​of the retardation films prepared in the examples and comparative examples were measured by the method described above. The results are shown in Table 1 below.

[0126] [Orientation] The orientation was evaluated by arranging two second polarizing plates in a crossed Nicol position on a light box (LED Viewer Pro HR-2, manufactured by Fujicolor) with the protective film 2 side facing inward, and placing a retardation film between the polarizing plates so that it was parallel to the absorption axis of one of the second polarizing plates. The orientation was then evaluated visually from the front (normal direction of the film) according to the following criteria. The results are shown in Table 1 below. A: No light leakage before or after placement of the retardation film. B: Light leakage before and after placement of the retardation film.

[0127] [Adhesion] The adhesion between the liquid crystal layer and the support in the retardation film was evaluated by a cross-cut test specified in JIS K5600-5-6, and the peelability from the support was evaluated according to the following criteria. The results are shown in Table 1 below. A: Less than 1% of the liquid crystal layer peeled off. B: 1% or more but less than 50% of the liquid crystal layer peeled off. C: 50% or more of the liquid crystal layer peeled off.

[0128] [Surface Condition] The prepared liquid crystal display device was placed on a diffused light source, and the surrounding area was shaded with black paper so that a 15 cm square size could be seen. Within the 15 cm square area, in-plane unevenness during black display was confirmed by observing from an oblique direction. The unevenness was evaluated according to the following evaluation criteria. The results are shown in Table 1 below. A: No in-plane unevenness was observed, and there was no problem. B: In-plane unevenness was observed, and it was unacceptable.

[0129] [Oblique Contrast] The prepared liquid crystal display device was placed over a diffused light source, and the brightness and color in black and white display were measured using an "EZ-Contrast XL88" measuring instrument (manufactured by ELDIM) at an azimuth angle of 0° (horizontal direction) to 359° counterclockwise in 1° increments, and at a polar angle of 0° (front direction) to 88° in 1° increments. At a polar angle of 60°, the contrast was compared in four directions, i.e., azimuth angles of 0°, 90°, 180°, and 270° in the absorption axis and transmission axis directions of the polarizer, and the oblique contrast was evaluated according to the following criteria. The contrast is the brightness of white display / the brightness of black display. The results are shown in Table 1 below. A: The contrast in all four directions is comparable to that of a liquid crystal display device without a retardation film. B: The contrast in all four directions is slightly lower than that of a liquid crystal display device without a retardation film, but is not a problem in practical use. C: The contrast in all four directions is clearly lower than that of a liquid crystal display device without a retardation film and is unacceptable.

[0130] [Display Performance] Regarding display performance, light leakage and color change during black display at a polar angle of 60° were evaluated according to the following evaluation criteria. The results are shown in Table 1 below. A: Very little light leakage and color change, excellent B: Little light leakage and color change, excellent C: Somewhat much light leakage and color change, but no practical problem D: Much light leakage and color change, unacceptable

[0131]

[0132] As shown in Table 1 above, when the half-width of the peak of the power spectrum obtained by fast Fourier transform of the reflectance spectrum of the retardation film exceeds 400 nm, the oblique contrast is found to be poor (Comparative Examples 1 and 2). Furthermore, when the non-polar component of the surface energy of the support is 45 mN / m or more, the surface condition is found to be poor (Comparative Example 3).

[0133] In contrast, it was found that when the half-width of the peak of the power spectrum obtained by fast Fourier transform of the reflectance spectrum of the retardation film is 400 nm or less, and the surface energy of the support has a nonpolar component of less than 45 mN / m and a polar component of 2 mN / m or more, the surface condition of the liquid crystal display device is good and the diagonal contrast is also good (Examples 1 to 5). In particular, a comparison between Example 1 and Example 2 revealed that when the surface energy of the support is 45 mN / m or more, the adhesion between the support and the liquid crystal layer is improved, and the diagonal contrast of the liquid crystal display device is better. Furthermore, a comparison between Example 2 and Example 4 revealed that when the support is a positive A plate, the display performance is good when used in a liquid crystal display device. Furthermore, a comparison between Example 2 and Example 3 revealed that when the liquid crystal composition contains a boronic acid monomer having a polymerizable group and a boronic acid group represented by formula (B), the adhesion between the support and the liquid crystal layer is improved, and the diagonal contrast of the liquid crystal display device is better. Furthermore, a comparison between Example 4 and Example 5 reveals that when the retardation in the thickness direction of the liquid crystal layer exhibits reverse wavelength dispersion, the display performance becomes good.

Claims

1. A retardation film having a support whose in-plane retardation shows reverse wavelength dispersion and a liquid crystal layer laminated directly on the support, wherein the support is a polymer film that has been stretched in at least one direction in its plane, the liquid crystal layer is a positive C plate formed by fixing the orientation state of a liquid crystal composition containing a liquid crystal compound, the surface energy of the support on the side on which the liquid crystal layer is laminated is such that the non-polar component is less than 45 mN / m and the polar component is 2 mN / m or more, the half-width of the peak of the power spectrum obtained by subjecting the reflectance spectrum of the retardation film to a fast Fourier transform is 400 nm or less, and the haze value of the retardation film is 1.0% or less.

2. The retardation film according to claim 1, wherein the surface energy of the surface of the support on which the liquid crystal layer is laminated is 45 mN / m or more.

3. The retardation film according to claim 1 or 2, wherein the material constituting the support is polycarbonate or polyester.

4. The retardation film according to claim 1 or 2, wherein the support is a positive A plate.

5. The retardation film according to claim 1 or 2, wherein the retardation in the thickness direction of the liquid crystal layer exhibits reverse wavelength dispersion.

6. The retardation film according to claim 1 or 2, wherein the liquid crystal composition further contains a boronic acid monomer having a polymerizable group and a boronic acid group represented by the following formula (B): In the formula (B), * represents a bonding position. １ and R ２ each independently represents a hydrogen atom, an optionally substituted aliphatic hydrocarbon group, an optionally substituted aryl group, or an optionally substituted heterocyclic group; R １ and R ２ may be linked to each other to form a ring.

7. A polarizing plate comprising the retardation film according to claim 1 or 2 and a polarizer.

8. The polarizing plate according to claim 7, wherein the absorption axis of the polarizer and the slow axis of the support of the retardation film are perpendicular or parallel to each other.

9. The polarizing plate according to claim 7, wherein the absorption axis of the polarizer is parallel to the slow axis of the support of the retardation film.

10. A liquid crystal display device comprising the polarizing plate according to claim 7.

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