Optical film, polarizing plate, and image display device

Abstract

The present invention addresses the problem of providing an optical film, a polarizing plate, and an image display device that maintain excellent alignment of a liquid crystal cured layer and have good adhesion between a base material and an alignment membrane. An optical film according to the present invention comprises: a base material; an alignment membrane provided on the base material; and a liquid crystal cured layer provided on the alignment membrane. The alignment membrane is a photo-alignment membrane formed by using an alignment membrane-forming composition containing a polymer (I) having a photo-alignment group and two or more different polymerizable groups. The optical film has a mixed region containing a component derived from the polymer (I) in a surface layer region on the alignment membrane side of the base material, and the thickness of the mixed region is more than 100 nm and less than 500 nm.

Description

Optical film, polarizing plate and image display device

[0001] The present invention relates to an optical film, a polarizing plate, and an image display device.

[0002] Optical films such as optical compensation sheets and retardation films are used in various image display devices to eliminate image coloration or widen the viewing angle. Stretched birefringent films have been used as optical films, but in recent years, the use of optical films having a liquid crystal cured layer instead of stretched birefringent films has been proposed.

[0003] Such a liquid crystal cured layer is known to be provided on an alignment film for aligning a liquid crystal compound, and a photo-alignment film that has been subjected to a photo-alignment treatment instead of a rubbing treatment is also known as this alignment film.

[0004] For example, Patent Document 1 describes a polymer (photoalignable copolymer) having, as a component forming a photoalignment film, a repeating unit containing a cinnamate group as a photoalignment group and a repeating unit containing a crosslinkable group (e.g., an epoxy group, an epoxycyclohexyl group, an oxetanyl group, and a functional group having an ethylenically unsaturated double bond) ([Claim 1] [Claim 2]), and further describes in the examples an optical film having a substrate, a photoalignment film, and a liquid crystal cured layer (

[0113] ).

[0005] International Publication No. 2019 / 225632

[0006] The present inventors have studied the optical film described in Patent Document 1 and have found that although the alignment of the cured liquid crystal layer is good, there is room for improvement in the adhesion between the substrate and the alignment film.

[0007] Therefore, an object of the present invention is to provide an optical film, a polarizing plate and an image display device that maintain excellent alignment of the cured liquid crystal layer and have good adhesion between the substrate and the alignment film.

[0008] As a result of intensive research to achieve the above-mentioned object, the present inventors have found that, for an optical film having a substrate, an alignment film provided on the substrate, and a liquid crystal cured layer provided on the alignment film, by using a photo-alignment film formed using an alignment film-forming composition containing a polymer (I) having a photo-alignable group and two or more different polymerizable groups as the alignment film, and by providing a mixed region containing a component derived from the polymer (I) with a predetermined thickness in the surface layer region of the substrate on the alignment film side, the excellent alignment of the liquid crystal cured layer is maintained and adhesion between the substrate and the alignment film is improved, and have completed the present invention. That is, the present inventors have found that the above-mentioned object can be achieved by the following configuration.

[0009] [1] An optical film having a substrate, an alignment film provided on the substrate, and a liquid crystal cured layer provided on the alignment film, wherein the alignment film is a photo-alignment film formed using a composition for forming an alignment film containing a polymer (I) having a photo-alignment group and two or more different polymerizable groups, and wherein a surface region of the substrate facing the alignment film has a mixed region containing a component derived from the polymer (I), and the thickness of the mixed region is more than 100 nm and less than 500 nm. [2] The optical film according to [1], wherein the polymer (I) is a copolymer having a repeating unit A represented by formula (A) described below, a repeating unit B represented by formula (B) described below, and a repeating unit C represented by formula (C) described below. [3] The optical film according to [2], wherein the content a of the repeating unit A, the content b of the repeating unit B, and the content c of the repeating unit C relative to the total mass of the polymer (I) satisfy the following ranges: 5≦a≦30, 20≦b≦45, and 50≦c≦75, respectively. [4] The optical film according to any one of [1] to [3], wherein the content of polymer (I) is 5 to 30 mass% based on the total mass of the solid content of the composition for forming an alignment film. [5] The optical film according to any one of [1] to [4], wherein the composition for forming an alignment film further contains polymer (II), which is a polymer other than polymer (I) and has a repeating unit B represented by formula (B) described below. [6] The optical film according to [5], wherein the Hansen solubility parameters of polymer (I) are δD(I), δP(I), and δH(I), respectively, and the Hansen solubility parameters of polymer (II) are δD(II), δP(II), and δH(II), respectively, satisfy formula (α) described below. [7] The optical film according to [5] or [6], wherein the content of polymer (I) is 5 to 30 mass% based on the total mass of polymer (I) and polymer (II). [8] The optical film according to any one of [1] to [7], wherein the liquid crystal cured layer is a layer formed by fixing a liquid crystal state of a smectic phase. [9] The optical film according to any one of [1] to [8], wherein the thickness of the mixed region is more than 130 nm and less than 200 nm.

[10] The optical film according to any one of [1] to [9], wherein the liquid crystal cured layer is a liquid crystal cured layer formed by fixing the alignment state of a liquid crystal composition containing a liquid crystal compound, wherein the liquid crystal compound is a rod-shaped liquid crystal compound, and wherein a refractive index difference Δn between the major axis direction and the minor axis direction of the rod-shaped liquid crystal compound satisfies formula (β) described below.

[11] The optical film according to any one of [1] to

[10] , wherein the liquid crystal cured layer is a liquid crystal cured layer formed by fixing the alignment state of a liquid crystal composition containing a liquid crystal compound, wherein the liquid crystal compound is a compound represented by formula (III) described below.

[12] The optical film according to

[11] , wherein Ar in formula (III) described below represents any aromatic ring selected from the group consisting of groups represented by formulas (Ar-1) to (Ar-5) described below.

[13] The optical film according to any one of [1] to

[12] , wherein the substrate has a thickness direction retardation of more than −10 nm and less than 10 nm at a wavelength of 550 nm.

[14] A polarizing plate having the optical film according to any one of [1] to

[13] and a polarizer.

[15] An image display device having the optical film according to any one of [1] to

[13] or the polarizing plate according to

[14] .

[16] The image display device according to

[15] , which is a liquid crystal display device.

[17] The image display device according to

[15] , which is an organic EL display device.

[0010] According to the present invention, it is possible to provide an optical film, a polarizing plate and an image display device that maintain excellent alignment of the cured liquid crystal layer and have good adhesion between the substrate and the alignment film.

[0011] Fig. 1 is a schematic cross-sectional view showing an example of the optical film of the present invention, and Fig. 2 is a schematic view illustrating a depth profile of the components of the alignment film detected by analyzing the components in the depth direction of the mixed region in the substrate by time-of-flight secondary ion mass spectrometry (TOF-SIMS).

[0012] The present invention will be described in detail below. 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 a stepwise manner may be replaced with the upper or lower limit of another stepwise manner. In this specification, the upper or lower limit of a numerical range described in a stepwise manner may be replaced with a value shown in the Examples. In this specification, each component may be a single substance corresponding to the component, or two or more substances may be used in combination. When two or more substances are used in combination for each component, the content of that component refers to the total content of the substances used in combination, unless otherwise specified. In addition, in this specification, "(meth)acrylate" is a notation representing "acrylate" or "methacrylate", "(meth)acrylic" is a notation representing "acrylic" or "methacrylic", and "(meth)acryloyl" is a notation representing "acryloyl" or "methacryloyl". In addition, the bonding direction of the divalent group (e.g., -O-CO-) represented in this specification is not particularly limited, and for example, "L 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.

[0013] 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. In the present invention, Re(λ) and Rth(λ) are values ​​measured at a wavelength λ using an AxoScan (manufactured by Axometrics). By inputting the average refractive index ((nx+ny+nz) / 3) and film thickness (d (μm)) into AxoScan, the following slow axis direction (°) is calculated: Re(λ) = R0(λ) Rth(λ) = ((nx+ny) / 2-nz)×d. Note that R0(λ) is displayed as a numerical value calculated by AxoScan, but it means Re(λ).

[0014] 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 7 to 24 carbon atoms, such as a phenoxycarbonyl group); a carbamoyl group (preferably a carbamoyl group having 1 to 48 carbon atoms, more preferably 1 to 24 carbon atoms, such as 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 24 or less carbon atoms, such as an amino group, methylamino group, N,N-dimethylamino group, N,N-dibutylamino group, tetradecylamino group, 2-ethylhexylamino group, or 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.

[0015] [Optical Film] The optical film of the present invention has a substrate, an alignment film provided on the substrate, and a liquid crystal cured layer provided on the alignment film. The optical film of the present invention is a photo-alignment film formed using a composition for forming an alignment film containing a polymer (I) having a photo-alignable group and two or more different polymerizable groups. The optical film of the present invention also has a mixed region containing a component derived from the polymer (I) in a surface region of the substrate facing the alignment film, and the thickness of the mixed region is more than 100 nm and less than 500 nm.

[0016] In the present invention, as described above, a photo-alignment film formed using an alignment film-forming composition containing a polymer (I) having a photo-alignment group and two or more different polymerizable groups is used as the alignment film. Furthermore, by providing a mixed region containing components derived from the polymer (I) to a specific thickness (more than 100 nm and less than 500 nm) in the surface region of the substrate facing the alignment film, excellent alignment of the liquid crystal cured layer is maintained and adhesion between the substrate and the alignment film is improved. While the details are not clear, the inventors speculate as follows: That is, by using an alignment film-forming composition containing a polymer (I) having a photo-alignment group and two or more different polymerizable groups, the formed photo-alignment film becomes a highly hard alignment film due to the curing reaction of multiple polymerizable groups, and it is believed that excellent alignment of the liquid crystal cured layer can be maintained. Furthermore, by providing a mixed region containing components derived from the polymer (I) to a specific thickness (more than 100 nm and less than 500 nm) in the surface region of the substrate facing the alignment film, an anchoring effect is exhibited, and adhesion between the substrate and the alignment film is improved.

[0017] Next, the structure of the optical film of the present invention will be described with reference to FIG. 1. FIG. 1 is a schematic cross-sectional view showing an example of an optical film. The optical film 10 shown in FIG. 1 includes a substrate 1, an alignment film 2, and a liquid crystal cured layer 3, in this order. The optical film 10 includes a mixed region 4 containing a component derived from polymer (I) in the surface region of the substrate 1 facing the alignment film 2, and the thickness d of the mixed region 4 is greater than 100 nm and less than 500 nm. Reference numeral 5 denotes a substrate region of the substrate 1 that does not contain a component derived from polymer (I). The liquid crystal cured layer 3 may also be a laminate of two or more different liquid crystal cured layers. For example, when the optical film of the present invention is used as an optical compensation film for an IPS (In-Plane-Switching) or FFS (Fringe-Field-Switching) liquid crystal display device, it is preferably a laminate of a positive A plate and a positive C plate. Various components used in the optical film will be described in detail below.

[0018] [Substrate] The substrate of the optical film of the present invention is not particularly limited as long as it has a mixed region containing a component derived from the polymer (I) in the surface layer region on the alignment film side.

[0019] The substrate is preferably a polymer film because it is easy to form a mixed region.The material of the polymer film can be exemplified by cellulose polymers, acrylic polymers having acrylic acid ester polymers such as polymethyl methacrylate and lactone ring-containing polymers, thermoplastic norbornene polymers, polycarbonate polymers, polyester polymers such as polyethylene terephthalate and polyethylene naphthalate, styrene polymers such as polystyrene and acrylonitrile-styrene copolymers (AS resins), polyolefin polymers such as polyethylene, polypropylene and ethylene-propylene copolymers, vinyl chloride polymers, amide polymers such as nylon and aromatic polyamides, imide polymers, sulfone polymers, polyethersulfone polymers, polyetheretherketone polymers, polyphenylene sulfide polymers, vinylidene chloride polymers, vinyl alcohol polymers, vinyl butyral polymers, arylate polymers, polyoxymethylene polymers, epoxy polymers, and polymers obtained by mixing these polymers. Among these, cellulose-based polymers (hereinafter also referred to as "cellulose acylate"), such as triacetyl cellulose (TAC), can be preferably used.

[0020] In the present invention, the retardation of the substrate in the thickness direction at a wavelength of 550 nm is preferably more than −10 nm and less than 10 nm, because this improves the alignment of the cured liquid crystal layer.

[0021] In the present invention, the thickness of the substrate (including the thickness of the mixed region) is not particularly limited, but is preferably 1 to 100 μm, more preferably 5 to 50 μm.

[0022] <Mixed Region> The substrate of the optical film of the present invention has a mixed region containing a component derived from the polymer (I) described below in a surface region on the side where an alignment film described below is to be provided. Here, the mixed region can be formed by, for example, adjusting the type of substrate, the type of solvent in the alignment film-forming composition described below, the drying time of the coating film, etc. when applying the alignment film-forming composition described below to the substrate (i.e., when forming the alignment film). Therefore, the "component derived from the polymer (I) described below" is formed when the polymer (I) contained in the alignment film-forming composition described below penetrates into the surface region on the alignment film side of the substrate. However, in the state of the optical film, i.e., after the alignment film and the cured liquid crystal layer are formed, at least one of the polymerizable groups of the polymer (I) disappears, and therefore corresponds to a polymer having a photoalignment group and a remaining polymerizable group.

[0023] The thickness of the mixed region is not particularly limited as long as it is more than 100 nm and less than 500 nm, but is preferably more than 130 nm and less than 200 nm because this improves the alignment of the cured liquid crystal layer and also improves the adhesion between the substrate and the alignment film. Here, the thickness of the mixed region corresponds to the depth region where secondary ions of both the component derived from the substrate and the component derived from polymer (I) are observed when depth analysis of the optical film is performed by TOF-SIMS, and can be measured by the method described below. In this specification, the thickness of the mixed region refers to the average thickness of the mixed region, and is determined by measuring the thicknesses of any five or more points in the mixed region by TOF-SIMS and taking the arithmetic average.

[0024] <Method for Measuring the Thickness of the Mixed Region> The thickness of the mixed region is measured by analyzing the components in the depth direction of the optical film by secondary ion mass spectrometry using a TOF-SIMS V (manufactured by ION TOF). In this specification, the depth direction refers to the direction toward the substrate, based on the surface of the optical film on the liquid crystal cured layer side. Specifically, as shown in FIG. 2 , the penetration thickness (d) of the mixed region is calculated from the difference between the depth (Da) at which the secondary ion intensity derived from the polymer (I) disappears and the depth (Db) at which the secondary ion intensity derived from the substrate is generated. In FIG. 2 , symbol C1 represents the result of the secondary ion intensity derived from the liquid crystal cured layer, symbol C2 represents the result of the secondary ion intensity derived from the polymer (I), and symbol C3 represents the result of the secondary ion intensity derived from the substrate.

[0025] [Alignment film] The alignment film of the optical film of the present invention is a photo-alignment film formed using a composition for forming an alignment film containing a polymer (I) having a photo-alignable group and two or more different polymerizable groups. Hereinafter, the components of the composition for forming an alignment film and the method for forming the alignment film will be described in detail.

[0026] <Polymer (I)> As described above, the polymer (I) contained in the composition for forming an alignment film is a polymer having a photoalignment group and two or more different polymerizable groups.Here, the photoalignment group refers to a group having a photoalignment function, which is induced by irradiation with anisotropic light (for example, plane polarized light, etc.), and rearrangement or anisotropic chemical reaction is induced.In view of excellent alignment uniformity, thermal stability and chemical stability, a photoalignment group that undergoes at least one of dimerization and isomerization under the action of light is preferred.In addition, the polymerizable group is not particularly limited, but a polymerizable group that can undergo radical polymerization or cation polymerization is preferred.

[0027] In the present invention, because the photo-alignable group has good photoreactivity and the two different types of polymerizable groups have good curability, it is preferable that the polymer (I) is a copolymer (hereinafter also formally abbreviated as "copolymer of the present invention") having a repeating unit A represented by formula (A) described later, a repeating unit B represented by formula (B) described later, and a repeating unit C represented by formula (C) described later.

[0028] (Repeating Unit A) The repeating unit A contained in the copolymer of the present invention is a repeating unit represented by the following formula (A).

[0029] In the above formula (A), R ａ represents a hydrogen atom or a substituent. ａ represents a divalent linking group, and A represents any photoalignable group selected from the group consisting of a polyene group, a stilbene group, a stilbazolium group, a chalcone group, a cinnamoyl group, an aromatic Schiff base, an aromatic hydrazone group, an azobenzene group, an azonaphthalene group, an aromatic heterocyclic azo group, a bisazo group, a formazan group, an azoxybenzene group, a coumarin group, and a maleimide group.

[0030] Next, R in the above formula (A) ａ In the above formula (A), the hydrogen atom or substituent represented by R ａ Examples of the substituent represented by one embodiment of the formula (1) include the substituents described in the above-mentioned Substituent Group A, and among them, a halogen atom, a linear, branched, or cyclic alkyl group having 1 to 20 carbon atoms, a linear halogenated alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, a cyano group, or an amino group is preferable.

[0031] Next, L in the above formula (A) ａ The divalent linking group represented by the formula (I) will be described. As the divalent linking group, a divalent linking group combining at least two or more groups selected from the group consisting of an optionally substituted linear, branched or cyclic alkylene group having 1 to 18 carbon atoms, an optionally substituted arylene group having 6 to 12 carbon atoms, an ether group (—O—), a carbonyl group (—C(═O)—), and an optionally substituted imino group (—NH—) is preferred, because the photoalignable group is more likely to interact with the liquid crystal compound and the alignment of the cured liquid crystal layer is improved.

[0032] Here, examples of the substituent that the alkylene group, arylene group, and imino group may have include the substituents described in the above-mentioned substituent group A, and particularly, include a halogen atom, an alkyl group, an alkoxy group, an aryl group, an aryloxy group, a cyano group, a carboxy group, an alkoxycarbonyl group, and a hydroxyl group.

[0033] Regarding the linear, branched, or cyclic alkylene group having 1 to 18 carbon atoms, specific examples of linear alkylene groups include methylene, ethylene, propylene, butylene, pentylene, hexylene, decylene, undecylene, dodecylene, tridecylene, tetradecylene, pentadecylene, hexadecylene, heptadecylene, and octadecylene groups. Specific examples of branched alkylene groups include dimethylmethylene, methylethylene, 2,2-dimethylpropylene, and 2-ethyl-2-methylpropylene groups. Specific examples of the cyclic alkylene group include a cyclopropylene group, a cyclobutylene group, a cyclopentylene group, a cyclohexylene group, a cyclooctylene group, a cyclodecylene group, an adamantane-diyl group, a norbornane-diyl group, and an exo-tetrahydrodicyclopentadiene-diyl group, and among these, a cyclohexylene group is preferable.

[0034] Specific examples of the arylene group having 6 to 12 carbon atoms include a phenylene group, a xylylene group, a biphenylene group, a naphthylene group, and a 2,2'-methylenebisphenyl group, and among these, a phenylene group is preferred.

[0035] Next, the photo-aligning group represented by A in the above formula (A) will be described. The photo-aligning group is any photo-aligning group selected from the group consisting of a polyene group, a stilbene group, a stilbazolium group, a chalcone group, a cinnamoyl group, an aromatic Schiff base, an aromatic hydrazone group, an azobenzene group, an azonaphthalene group, an aromatic heterocyclic azo group, a bisazo group, a formazan group, an azoxybenzene group, a coumarin group, and a maleimide group.

[0036] Of these photoalignable groups, a cinnamoyl group is preferred, and specifically, a group represented by the following formula (a1) is more preferred, and a group represented by the following formula (a2) is even more preferred.

[0037] In the above formula (a1), one of the two * is L ａ and the other represents a hydrogen atom or a substituent. ａ In addition, R in the above formula (a1) represents the bonding position. ５ ~R ８ and R in the above formula (a2) ５ ~R ９ each independently represents a hydrogen atom or a substituent, and two adjacent groups may be bonded to form a ring.

[0038] Here, R ５ ~R ９ The substituents represented by one aspect of the formula (a3) ​​are preferably each independently a halogen atom, a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, a linear halogenated alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, a cyano group, an amino group, or a group represented by the following formula (a3), because the photoalignable group is more likely to interact with the liquid crystal compound and the alignment of the cured liquid crystal layer is improved. Specific examples of substituents other than the group represented by the following formula (a3) ​​include R ａ Examples of the substituent include those described as examples of the substituents shown in one embodiment of the above. In the formula (a3), * represents the bonding position to the benzene ring in the formula (a2), and R １０ represents a monovalent organic group.

[0039] R in the above formula (a3) １０Examples of the monovalent organic group represented by include linear or cyclic alkyl groups having 1 to 20 carbon atoms. As the linear alkyl group, alkyl groups having 1 to 6 carbon atoms are preferred, and specific examples thereof include methyl, ethyl, and n-propyl groups, with methyl and ethyl groups being preferred. As the cyclic alkyl group, alkyl groups having 3 to 6 carbon atoms are preferred, and specific examples thereof include cyclopropyl, cyclopentyl, and cyclohexyl groups, with cyclohexyl being preferred. Note that, in the above formula (a3), R １０ The monovalent organic group represented by may be a combination of the above-mentioned linear alkyl groups and cyclic alkyl groups either directly or via a single bond.

[0040] In the present invention, the photoalignable group is easily interacted with the liquid crystal compound, and the alignment of the cured liquid crystal layer is improved. For this reason, R ５ ~R ８ or R in the above formula (a2) ５ ~R ９ At least one of (particularly, R ９ ) is preferably the above-mentioned substituent, and is more preferably an electron-donating substituent because the linearity of the resulting copolymer is improved and the reaction efficiency is improved when irradiated with polarized light. Here, the electron-donating substituent (electron-donating group) refers to a substituent having a Hammett value (Hammett substituent constant σp) of 0 or less, and examples of the above-mentioned substituents include alkyl groups, halogenated alkyl groups, and alkoxy groups. Of these, an alkoxy group is preferred, and an alkoxy group having 6 to 16 carbon atoms is more preferred, and an alkoxy group having 7 to 10 carbon atoms is even more preferred because the alignment of the cured liquid crystal layer is further improved.

[0041] Specific examples of the repeating unit A represented by the above formula (A) include the repeating units A-1 to A-160 shown below: In the following formula, Me represents a methyl group.

[0042]

[0043]

[0044]

[0045]

[0046]

[0047]

[0048]

[0049]

[0050] (Repeating Unit B) The repeating unit B contained in the copolymer of the present invention is a repeating unit represented by the following formula (B).

[0051] In the above formula (B), R ｂ represents a hydrogen atom or a substituent. ｂ Examples of the substituents represented by one embodiment of the formula (A) include R ａ In addition, examples of the substituents include those described as examples of the substituents shown in one embodiment of L ｂ represents a divalent linking group. ｂ The divalent linking group represented by is L in the above formula (A). ａ Examples of the divalent linking group include those described above for the divalent linking group represented by the formula (PG-1) and the formula (PG-2) and the formula (PG-3) are also included.

[0052] In the above formulas (PG-1) to (PG-3), * represents L ｂ In the above formulas (PG-1) and (PG-2), R ｄ represents a hydrogen atom, a halogen atom, a methyl group, an ethyl group, or a trifluoromethyl group. ｄ may be the same or different.

[0053] Among the polymerizable groups represented by the above formulae (PG-1) to (PG-3), the polymerizable group represented by the above formula (PG-1) is preferred, and a (meth)acryloyl group is more preferred, because this provides good adhesion to the liquid crystal cured layer.

[0054] Specific examples of the repeating unit B represented by the above formula (B) include the repeating units B-1 to B-29 shown below.

[0055] (Repeating Unit C) The repeating unit C contained in the copolymer of the present invention is a repeating unit represented by the following formula (C).

[0056] In the above formula (C), R ｃ represents a hydrogen atom or a substituent. ｃ Examples of the substituents represented by one embodiment of the formula (A) include R ａ In addition, examples of the substituents include those described as examples of the substituents shown in one embodiment of L ｃ represents a divalent linking group. ｃ The divalent linking group represented by is L in the above formula (A). ａ Examples of the divalent linking group include those described above for the divalent linking group represented by the formula (PG-1). C represents any one of the polymerizable groups represented by the following formulas (PG-4) to (PG-9).

[0057] In the above formulas (PG-4) to (PG-9), * represents L ｃ In the above formulae (PG-5) to (PG-9), R ｄrepresents a hydrogen atom, a halogen atom, a methyl group, an ethyl group, or a trifluoromethyl group, provided that multiple R ｄ may be the same or different.

[0058] Among the polymerizable groups represented by the above formulae (PG-4) to (PG-9), the polymerizable group represented by the above formula (PG-9) is preferred because it can further suppress relaxation of the photo-alignment film due to the composition, particularly the organic solvent in the composition, when forming a liquid crystal cured layer.

[0059] Specific examples of the repeating unit C represented by the above formula (C) include repeating units C-1 to C-23 shown below.

[0060] In the copolymer of the present invention, the content a (mass %) of the repeating unit A represented by the above formula (A), the content b (mass %) of the repeating unit B represented by the above formula (B), and the content c (mass %) of the repeating unit C represented by the above formula (C) are preferably 5≦a≦30, 20≦b≦45, and 50≦c≦75, respectively, and more preferably 7≦a≦22, 23≦b≦38, and 55≦c≦70, for the reasons that the alignment of the cured liquid crystal layer is improved and the adhesion between the substrate and the alignment film is also improved.

[0061] (Other Repeating Units) The copolymer of the present invention may contain other repeating units in addition to the repeating units A, B, and C described above, as long as the other repeating units do not impair the effects of the present invention. Examples of monomers (radical polymerizable monomers) that form such other repeating units include acrylic acid ester compounds, methacrylic acid ester compounds, maleimide compounds, acrylamide compounds, acrylonitrile, maleic anhydride, styrene compounds, and vinyl compounds.

[0062] The method for synthesizing the copolymer of the present invention is not particularly limited, and the copolymer can be synthesized, for example, by mixing a monomer forming the repeating unit A described above, a monomer forming the repeating unit B described above, a monomer forming the repeating unit C described above, and a monomer forming any other repeating unit, and polymerizing the mixture in an organic solvent using a radical polymerization initiator.

[0063] The weight average molecular weight (Mw) of the copolymer of the present invention is preferably 10,000 to 500,000, more preferably 10,000 to 100,000, because this improves the alignment of the cured liquid crystal layer. Here, the weight average molecular weight and number average molecular weight in the present invention are values ​​measured by gel permeation chromatography (GPC) under the following conditions. Solvent (eluent): THF (tetrahydrofuran) Apparatus name: TOSOH HLC-8320GPC Column: Three TOSOH TSKgel Super HZM-H (4.6 mm x 15 cm) connected together Column temperature: 40°C Sample concentration: 0.1% by mass Flow rate: 1.0 ml / min Calibration curve: A calibration curve using seven samples of TSK standard polystyrene manufactured by TOSOH with Mw = 2,800,000 to 1,050 (Mw / Mn = 1.03 to 1.06) was used.

[0064] In the present invention, the content of the polymer (I) is preferably 5 to 30 mass %, more preferably 7.5 to 15 mass %, based on the total mass of the solid content of the composition for forming an alignment film, because the alignment property of the cured liquid crystal layer is improved and the adhesion between the substrate and the alignment film is also improved.

[0065] <Polymer (II)> The composition for forming an alignment film preferably further contains a polymer (II) that does not fall under the category of the above-mentioned polymer (I) and has a repeating unit B represented by the above-mentioned formula (B), for the reason that the alignment property of the cured liquid crystal layer becomes better.

[0066] When the composition for forming an alignment film contains polymer (II), the alignment property of the cured liquid crystal layer becomes even better, and for this reason, it is preferable that the following formula (α) is satisfied when the dispersion force term of the Hansen solubility parameters of polymer (I) is δD(I), the polar term is δP(I), and the hydrogen bond term is δH(I), and the dispersion force term of the Hansen solubility parameters of polymer (II) is δD(II), the polar term is δP(II), and the hydrogen bond term is δH(II).

[0067] Here, the Hansen solubility parameters (HSP) represent the solubility of a substance in three dimensional space by dividing it into three components (dispersion term δd, polar term δp, and hydrogen bonding term δh). The dispersion term δd represents the effect of dispersion forces, the polar term δp represents the effect of dipole-dipole forces, and the hydrogen bonding term δh represents the effect of hydrogen bonding forces. The definition and calculation of the Hansen solubility parameters are described in "Hansen Solubility Parameters: A User's Handbook" by Charles M. Hansen (CRC Press, 2007). Furthermore, by using computer software Hansen Solubility Parameters in Practice (HSPiP), the Hansen solubility parameters can be easily estimated from the chemical structure of compounds for which literature values ​​are unknown. In the present invention, the dispersion parameter δd, polar parameter δp, and hydrogen bonding parameter δh of the liquid crystal compound and additives are determined using estimated values ​​using HSPiP version 5.1.08.

[0068] When the composition for forming an alignment film contains the polymer (II), the content of the polymer (I) is preferably 5 to 30 mass %, more preferably 7.5 to 15 mass %, based on the total mass of the polymer (I) and the polymer (II), because the alignment property of the cured liquid crystal layer becomes better and the adhesion between the substrate and the alignment film also becomes better.

[0069] <Thermal Acid Generator> The composition for forming an alignment film preferably contains a thermal acid generator. The thermal acid generator is not particularly limited as long as it can generate an acid by heat, and examples thereof include onium salts such as sulfonium salts, benzothiazolium salts, ammonium salts, and phosphonium salts. Specific examples of thermal acid generators include salts of a cation selected from benzyl(4-hydroxyphenyl)methylsulfonium, (4-acetoxyphenyl)dimethylsulfonium, (4-hydroxyphenyl)dimethylsulfonium, (2-methylbenzyl)(4-hydroxyphenyl)methylsulfonium, (1-naphthylmethyl)(4-hydroxyphenyl)methylsulfonium, and benzyl(4-acetoxyphenyl)methylsulfonium, and an anion selected from tris(pentafluoroethyl)trifluorophosphate, hexafluorophosphate, tetrafluoroborate, tetrakis(pentafluorophenyl)borate, hexafluoroantimonate, p-toluenesulfonate, dodecylbenzenesulfonate, trifluoromethanesulfonate, and perfluorobutanesulfonate.

[0070] <Solvent> The composition for forming an alignment film preferably contains a solvent from the viewpoint of workability. Examples of solvents include ketones (e.g., acetone, 2-butanone, methyl ethyl ketone (MEK), methyl isobutyl ketone, cyclopentanone, and cyclohexanone), ethers (e.g., dioxane and tetrahydrofuran), aliphatic hydrocarbons (e.g., hexane), alicyclic hydrocarbons (e.g., cyclohexane), aromatic hydrocarbons (e.g., toluene, xylene, and trimethylbenzene), halogenated carbons (e.g., dichloromethane, dichloroethane, dichlorobenzene, and chlorotoluene), esters (e.g., methyl acetate, ethyl acetate, and butyl acetate), water, alcohols (e.g., ethanol, isopropanol, butanol, and cyclohexanol), cellosolves (e.g., methyl cellosolve and ethyl cellosolve), cellosolve acetates, sulfoxides (e.g., dimethyl sulfoxide), and amides (e.g., dimethylformamide and dimethylacetamide). One type of solvent may be used alone, or two or more types may be used in combination.

[0071] In the present invention, it is preferable to use a ketone solvent (particularly MEK) and an ester solvent (particularly butyl acetate) in combination, because this makes it easier to form a mixed region on the substrate. A mixed solvent in which the mass ratio (ketones:esters) is 25:75 to 55:45 is more preferable, a mixed solvent in which the mass ratio is 30:70 to 50:50 is even more preferable, and a mixed solvent in which the mass ratio is 35:65 to 45:55 is particularly preferable.

[0072] <Method for Producing Alignment Film> The method for producing the alignment film is not particularly limited, and the alignment film can be produced using the above-mentioned composition for forming an alignment film, for example, by a production method including a coating step of applying the composition for forming an alignment film onto a substrate to form a coating film, a heating step of heating and drying the coating film, and a light irradiation step of irradiating the dried coating film with polarized light or unpolarized light from an oblique direction to the coating film surface. Each step in the production method will be described in detail below.

[0073] (Coating Step) The coating method in the coating step is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include spin coating, die coating, gravure coating, flexographic printing, and inkjet printing.

[0074] (Heating Step) The temperature in the heating step is not particularly limited as long as it is a temperature at which the solvent contained in the coating film can be dried and removed, but is preferably 100 to 150° C. The time for the heating step is not particularly limited as long as it is a time at which the solvent contained in the coating film can be dried and removed, but is preferably 30 seconds to 5 minutes.

[0075] In the light irradiation step, the polarized light to be irradiated onto the dried coating film is not particularly limited, and examples thereof include linearly polarized light, circularly polarized light, and elliptically polarized light, with linearly polarized light being preferred. The "oblique direction" in which unpolarized light is irradiated is not particularly limited as long as it is a direction tilted at a polar angle θ (0<θ<90°) with respect to the normal direction of the coating film surface, and can be appropriately selected depending on the purpose, with θ being preferably 20 to 80°.

[0076] The wavelength of the polarized or unpolarized light is not particularly limited as long as it is light to which the photo-alignable group is photosensitive, and examples thereof include ultraviolet light, near ultraviolet light, and visible light, with near ultraviolet light of 250 to 450 nm being preferred. Examples of light sources for irradiating polarized or unpolarized light include xenon lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, LED (Light Emitting Diode) lamps, and metal halide lamps. The wavelength range of the ultraviolet or visible light obtained from such light sources can be limited by using an interference filter or color filter. Linearly polarized light can also be obtained by using a polarizing filter or polarizing prism on the light from these light sources.

[0077] The integrated amount of polarized or unpolarized light is not particularly limited, and is 1 to 300 mJ / cm ２ is preferred, and 5 to 100 mJ / cm ２ The illuminance of polarized or unpolarized light is not particularly limited, and is 0.1 to 300 mW / cm ２ is preferred, and 1 to 100 mW / cm２ is more preferred.

[0078] In the present invention, the thickness of the alignment film is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 200 to 1000 nm, more preferably 200 to 600 nm.

[0079] [Liquid Crystal Cured Layer] The liquid crystal cured layer of the optical film of the present invention is a liquid crystal cured layer obtained by fixing the alignment state of a liquid crystal composition containing a liquid crystal compound.

[0080] Liquid Crystal Compounds 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 compounds 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. Furthermore, the liquid crystal compound preferably has a polymerizable group to fix the alignment state of the liquid crystal composition. Examples of polymerizable groups include acryloyl, methacryloyl, epoxy, and vinyl groups. The alignment of such liquid crystal compounds can be fixed by polymerization. Note that once the liquid crystal compound is fixed by polymerization, it no longer needs to exhibit liquid crystallinity.

[0081] 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.

[0082] In the present invention, it is preferable that the liquid crystal cured layer is a layer in which a liquid crystal state of a smectic phase is fixed, that is, a layer in which a liquid crystal composition containing the above liquid crystal compound is fixed in an oriented state of a smectic phase, because this improves the alignment of the liquid crystal cured layer.

[0083] In the present invention, for the reason that the alignment of the cured liquid crystal layer is better, it is preferable that the liquid crystal compound is a rod-shaped liquid crystal compound, and that the refractive index difference Δn between the long axis direction and the short axis direction satisfies the following formula (β): Δn(450) / Δn(550)<1.0(β) In the above formula (β), Δn(450) represents the refractive index difference at 450 nm, and Δ(550) represents the refractive index difference at 550 nm. The long axis direction of a rod-shaped liquid crystal compound refers to the direction of the longest axis in the molecule, and the short axis direction refers to the direction perpendicular to the long axis direction. The refractive index difference Δn is calculated by dividing the Re(λ) value (nm) measured by the above-described method for a cured liquid crystal layer prepared using a rod-shaped liquid crystal compound by the film thickness value (nm) of the cured liquid crystal layer. The cured liquid crystal layer to be measured, i.e., the cured liquid crystal layer prepared using a rod-shaped liquid crystal compound, is a cured liquid crystal layer prepared by the following procedure. That is, liquid crystal composition L having the following composition is applied by spin coating to a glass substrate with a rubbed polyimide alignment film (SE-150 manufactured by Nissan Chemical Industries, Ltd.). The coating film is then heated and aligned at a temperature at which the liquid crystal exhibits liquid crystallinity to form a liquid crystal layer. The liquid crystal layer is then cooled to a temperature 40°C lower than the temperature at which the liquid crystal exhibits liquid crystallinity, and the liquid crystal composition L is then oriented at 1000 mJ / cm. ２ The alignment is fixed by ultraviolet irradiation to form a liquid crystal hardened layer.

[0084] Liquid crystal composition L - Rod-like liquid crystal compound 15.00 parts by mass - Photopolymerization initiator (Irgacure 819, manufactured by BASF) 0.45 parts by mass - Fluorine-containing compound A below 0.12 parts by mass - Chloroform 35.00 parts by mass -----------------------------------------------------------------

[0085] Fluorine-containing compound A

[0086] In the present invention, the liquid crystal compound is preferably a compound represented by the following formula (III) because the alignment of the cured liquid crystal layer is improved. １ -L １ -D ５ - (A １ ) ａ１ -D ３ - (G １ ) ｇ１ -D １ -[Ar-D ２ 〕 ｑ１ - (G ２ ) ｇ２ -D ４ - (A ２ ) ａ２ -D ６ -L ２ -P ２ (III)

[0087] In the above formula (III), 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. In addition, q1 represents 1 or 2. In addition, D 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. However, when q1 is 2, a plurality of D ２ may be the same or different. 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 L 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 P ２ each independently represents a monovalent organic group; P １ and P ２ At least one of the groups represents a polymerizable group. However, when Ar is an aromatic ring represented by formula (Ar-3) described later, P １ and P ２ and P in formula (Ar-3) described below. ３ and P ４At least one of the groups represented by the formula (I) represents a polymerizable group. Ar 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 - may be substituted with -O-, -S- or -NH-, provided that when q1 is 2, the multiple Ar's may be the same or different.

[0088] In the above formula (III), 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 formed cured liquid crystal layer is improved.

[0089] In the above formula (III), q1 is preferably 1.

[0090] In the above formula (III), D １ , D ２ , D ３ , D ４ , D ５ and D ６ Examples of the divalent linking group in one embodiment 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-CR １ 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 -, -NR５ -CR １ R ２ - and -CO-NR ５ - and so on. 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.

[0091] In the above formula (III), G １ and G ２ Examples of the aromatic ring having 6 to 20 carbon atoms in 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.

[0092] In the above formula (III), G １ and G ２ The divalent alicyclic hydrocarbon group having 5 to 20 carbon atoms shown in one embodiment of (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.

[0093] In the present invention, the durability of the formed cured liquid crystal layer is improved by increasing the G １ and G ２ 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.

[0094] In addition, in the above formula (III), 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.

[0095] In the above formula (III), A １ and A ２ As an aromatic ring having 6 to 20 carbon atoms in one embodiment, G in the above formula (III) １ and G ２ In addition, in the above formula (III), A １ and A ２ As an embodiment of the divalent alicyclic hydrocarbon group having 5 to 20 carbon atoms, there is mentioned G １ and G ２ The same as those explained in A １ and A 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.

[0096] In the above formula (III), L １ and L ２Examples of the divalent aliphatic hydrocarbon group having 1 to 20 carbon atoms represented by one embodiment of 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.

[0097] In the above formula (III), P １ and P ２Examples of the monovalent organic group represented by the formula (I) include the substituents described in the above-mentioned Substituent Group A, among which can be mentioned alkyl groups, aryl groups, heteroaryl groups, alkoxy groups, cyano groups, and carboxy groups. 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 preferred.

[0098] In the above formula (III), P １ and P ２The polymerizable group represented by at least one of the above 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 polymerization rate of an acryloyloxy group is generally known to be faster, 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 of the following formulas (P-1) to (P-20):

[0099]

[0100] In the formula (III), P in the formula (III) is preferably 0.05 to 0.15 because the durability of the formed cured liquid crystal layer is improved. １ and P ２ However, each of them is preferably a polymerizable group, and more preferably an acryloyloxy group or a methacryloyloxy group.

[0101] On the other hand, in the above formula (III), an aromatic ring having 6 to 20 carbon atoms as one embodiment of Ar is G in the above formula (III). １ and G ２ In addition, in the above formula (III), examples of the divalent alicyclic hydrocarbon group having 5 to 20 carbon atoms represented by one embodiment of Ar include the group G in the above formula (III). １ and G ２In addition, with regard to Ar, 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.

[0102] In the present invention, for the reason that the alignment property of the cured liquid crystal layer is further improved, the liquid crystal compound is preferably a compound having any aromatic ring selected from the group consisting of groups represented by the following formulas (Ar-1) to (Ar-5), and more preferably a compound represented by the above formula (III) in which Ar in the above formula (III) represents any aromatic ring selected from the group consisting of groups represented by the following formulas (Ar-1) to (Ar-5). In the following formulas (Ar-1) to (Ar-5), * represents a bonding site, but when Ar in the above formula (III) represents any aromatic ring selected from the group consisting of groups represented by the following formulas (Ar-1) to (Ar-5), * represents D １ or D ２ represents the bonding position with

[0103]

[0104] 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 １ represents 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 substituted with -O-, -S- or -NH-. ６Specific examples of the alkyl group having 1 to 6 carbon atoms represented by Y 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 Y include aryl groups such as phenyl, 2,6-diethylphenyl, and naphthyl. １ Examples of the aromatic heterocyclic group having 3 to 12 carbon atoms represented by Y include heteroaryl groups such as thienyl, thiazolyl, furyl, and pyridyl, as well as groups obtained by removing one hydrogen atom from an indole ring, a benzofuran ring, a benzothiophene ring, a benzimidazole ring, a benzothiazole ring, and 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 Y include a cyclohexylene group, a cyclopentylene group, a norbornylene group, and an adamantylene group. １ Examples of the substituent that may be possessed by 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.

[0105] In addition, in the above formulas (Ar-1) to (Ar-5), Z １ , Z ２ and Z ３ each 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 ~R１２ 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 １０Specific 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.

[0106] 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 (III). 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 group include those similar to those explained in the above formula (Ar-1).

[0107] 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 the formula (I) include the substituents described in the above-mentioned group A of substituents, and among them, an alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group, or a halogen atom is preferred.

[0108] 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—(RＣ１ ) 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, 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, a hydroxyl group, etc.

[0109] 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 (III). 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.

[0110] In addition, in the above formula (Ar-3), L ３ and L 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 include those 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, examples of the aliphatic hydrocarbon group include L in the above formula (III). １ and L ２Examples of the above-described examples are the same as those described above.

[0111] In addition, in the above formula (Ar-3), P ３ and P ４ each independently represents a monovalent organic group; P ３ and P ４ At least one of them represents a polymerizable group. １ and P ２ Examples of the polymerizable group include the same as those described above. １ and P ２ Examples of the above-described examples are the same as those described above.

[0112] In the above formulas (Ar-4) to (Ar-5), 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 formulas (Ar-4) to (Ar-5), 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. ３ Specific examples of the alkyl group having 1 to 20 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, and among these, an alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group, or a halogen atom is preferred.

[0113] Examples of the compound represented by formula (III) include the polymerizable compounds described in paragraphs

[0019] to

[0023] of JP 2019-139222 A; the polymerizable compounds described in paragraphs

[0059] to

[0061] of WO 2019 / 160014; the polymerizable compounds described in paragraph

[0055] of WO 2019 / 160016; compounds (1-1) to (1-19) represented by the following formulas; compounds (2-1) to (2-5) represented by the following formulas; and the like. In the structure of compound (1-14), 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 compound (1-14) represents a mixture of positional isomers in which the position of the methyl group is different.

[0114]

[0115]

[0116]

[0117]

[0118]

[0119]

[0120]

[0121] Further, as the compound represented by the formula (III), for example, the general formula (1) described in JP-A-2010-084032 compounds (particularly, compounds described in paragraphs

[0067] to

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

[0036] to

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

[0043] to

[0055] ), and, paragraphs

[0025] to

[0056] of WO 2021 / 060427 include compounds described therein.

[0122] <Other Polymerizable Compounds> From the viewpoints of alignment temperature and solubility, the liquid crystal composition preferably contains, in addition to the above-described liquid crystal compound, another polymerizable compound having one or more polymerizable groups. Here, the polymerizable group possessed by the other polymerizable compound is not particularly limited, and preferred examples thereof include the polymerizable groups represented by any of the above-described formulas (P-1) to (P-20).

[0123] The other polymerizable compound is preferably an other polymerizable compound having 2 to 4 polymerizable groups, more preferably an other polymerizable compound having 2 polymerizable groups, for the reason that the durability of the formed liquid crystal cured layer is further improved.

[0124] Examples of such other polymerizable compounds include compounds represented by formulae (M1), (M2), and (M3) described in paragraphs

[0030] to

[0033] of JP2014-077068A, and more specifically, specific examples described in paragraphs

[0046] to

[0055] of the same publication.

[0125] <Polymerization initiator> The liquid crystal composition preferably contains a polymerization initiator. The polymerization initiator used is preferably a photopolymerization initiator capable of initiating a polymerization reaction by ultraviolet irradiation. Examples of the photopolymerization initiator include α-carbonyl compounds (described in U.S. Pat. Nos. 2,367,661 and 2,367,670), acyloin ethers (described in U.S. Pat. No. 2,448,828), α-hydrocarbon-substituted aromatic acyloin compounds (described in U.S. Pat. No. 2,722,512), polynuclear quinone compounds (described in U.S. Pat. Nos. 3,046,127 and 2,951,758), and mixtures of triarylimidazole dimers and p-aminophenyl ketones. (described in U.S. Pat. No. 3,549,367), acridine and phenazine compounds (described in JP-A-60-105667 and U.S. Pat. No. 4,239,850), oxadiazole compounds (described in U.S. Pat. No. 4,212,970), acylphosphine oxide compounds (described in JP-B-63-40799, JP-B-5-29234, JP-A-10-95788, and JP-A-10-29997), etc. In the present invention, the polymerization initiator is preferably an oxime-type polymerization initiator, and specific examples thereof include the initiators described in paragraphs

[0049] to

[0052] of WO 2017 / 170443.

[0126] <Solvent> The liquid crystal composition preferably contains a solvent from the viewpoint of workability in forming a cured liquid crystal layer. Specific examples of the solvent 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., methyl acetate, ethyl acetate, butyl acetate, etc.), water, alcohols (e.g., ethanol, isopropanol, butanol, cyclohexanol, etc.), cellosolves (e.g., methyl cellosolve, ethyl cellosolve, etc.), cellosolve acetates, sulfoxides (e.g., dimethyl sulfoxide, etc.), amides (e.g., dimethylformamide, dimethylacetamide, etc.), and the like. These may be used alone or in combination of two or more.

[0127] <Leveling Agent> The liquid crystal composition preferably contains a leveling agent from the viewpoint of facilitating alignment control. Such a leveling agent is preferably a fluorine-based leveling agent or a silicon-based leveling agent because of its high leveling effect relative to the amount added, and more preferably a fluorine-based leveling agent from the viewpoint of being less likely to cause bleeding (bloom, bleed). Specific examples of the leveling agent include compounds described in paragraphs

[0079] to

[0102] of JP2007-069471A, compounds represented by general formula (I) described in JP2013-047204A (particularly compounds described in paragraphs

[0020] to

[0032] ), and compounds represented by general formula (I) described in JP2012-211306A (particularly compounds

[0022] to

[0029] ). Examples of the compound include the compounds described in paragraphs

[0076] to

[0078] and

[0082] to

[0084] ), liquid crystal alignment promoters represented by general formula (I) described in JP-A-2002-129162 (particularly the compounds described in paragraphs

[0076] to

[0078] and

[0082] to

[0084] ), and compounds represented by general formulas (I), (II), and (III) described in JP-A-2005-099248 (particularly the compounds described in paragraphs

[0092] to

[0096] ). The compound may also function as an alignment control agent, which will be described later.

[0128] <Alignment Control Agent> The liquid crystal composition may contain an alignment control agent, if necessary. The alignment control agent can form various alignment states such as homogeneous alignment, homeotropic alignment (vertical alignment), tilted alignment, hybrid alignment, and cholesteric alignment, and can also realize a specific alignment state by controlling it more uniformly and more precisely.

[0129] As an alignment control agent that promotes homogeneous alignment, for example, a low molecular weight alignment control agent or a polymer alignment control agent can be used. For low molecular weight alignment control agents, see, for example, paragraphs

[0009] to

[0083] of JP 2002-20363 A, paragraphs

[0111] to

[0120] of JP 2006-106662 A, and paragraphs

[0021] to

[0029] of JP 2012-211306 A, the contents of which are incorporated herein by reference. Furthermore, for polymer alignment control agents, see, for example, paragraphs

[0021] to

[0057] of JP 2004-198511 A, and paragraphs

[0121] to

[0167] of JP 2006-106662 A, the contents of which are incorporated herein by reference.

[0130] Furthermore, examples of alignment control agents that form or promote homeotropic alignment include boronic acid compounds and onium salt compounds. Specifically, the compounds described in JP-A-2008-225281, paragraphs

[0023] to

[0032] , JP-A-2012-208397, paragraphs

[0052] to

[0058] , JP-A-2008-026730, paragraphs

[0024] to

[0055] , and JP-A-2016-193869, paragraphs

[0043] to

[0055] , etc., can be referred to, the contents of which are incorporated herein by reference.

[0131] On the other hand, cholesteric alignment can be achieved by adding a chiral dopant to the liquid crystal composition, and the direction of rotation of the cholesteric alignment can be controlled by the chirality of the dopant. The pitch of the cholesteric alignment can be controlled by the alignment control force of the chiral dopant.

[0132] When an alignment control agent is contained, its content is preferably 0.01 to 10 mass %, more preferably 0.05 to 5 mass %, based on the total mass of solids in the composition. When the content is within this range, a desired alignment state can be achieved, and a uniform, highly transparent cured product can be obtained without precipitation, phase separation, alignment defects, etc.

[0133] <Other Components> The liquid crystal composition may contain components other than the above-mentioned components, such as a surfactant, a tilt angle control agent, an alignment aid, a plasticizer, and a crosslinking agent.

[0134] <Method for Producing a Cured Liquid Crystal Layer> Examples of methods for forming a cured liquid crystal layer include a method in which the liquid crystal composition described above is used to achieve a desired alignment state, followed by polymerization to fix the liquid crystal. While the conditions for achieving the desired alignment state are not particularly limited, a heat treatment is preferably performed, and a cooling treatment after the heat treatment is more preferred. From the viewpoint of manufacturability, the heating temperature in the heat treatment is preferably 10 to 250°C, more preferably 50 to 200°C, and even more preferably 70 to 150°C. Furthermore, the heating time in the heat treatment is preferably 1 to 300 seconds, more preferably 1 to 60 seconds. Furthermore, the temperature in the cooling treatment after the heat treatment is not particularly limited as long as it is lower than the heating temperature in the heat treatment, but is preferably room temperature (23°C) to 80°C. Furthermore, while the conditions for the polymerization are not particularly limited, ultraviolet light is preferably used in the polymerization by light irradiation. The irradiation dose is 10 mJ / cm. ２ ~50 J / cm ２ is preferred, and 20 mJ / cm ２ ~5 J / cm ２ More preferably, 30 mJ / cm ２ ~3 J / cm ２ is more preferably 50 to 1000 mJ / cm ２ is particularly preferred. In order to promote the polymerization reaction, the polymerization may be carried out under heating conditions. The liquid crystal cured layer can be formed on any support or alignment film in an optical film described later, or on a polarizer in a polarizing plate described later.

[0135] The orientation state of the liquid crystal compound in the cured liquid crystal layer may be any of horizontal, vertical, tilted, and twisted orientations, and is preferably fixed in a state of horizontal orientation relative to the main surface of the cured liquid crystal layer. In this specification, "horizontal orientation" refers to a state in which the major axis direction of the liquid crystal compound is parallel to the main surface of the cured liquid crystal layer (or, when the cured liquid crystal layer is formed on a member such as a support or an alignment film, the surface of the member). Strict parallelism is not required, and in this specification, it refers to an orientation in which the angle between the major axis direction of the liquid crystal compound and the main surface of the cured liquid crystal layer is less than 10°. In the cured liquid crystal layer, the angle between the major axis direction of the liquid crystal compound and the main surface of the cured liquid crystal layer is preferably 0 to 5°, more preferably 0 to 3°, and even more preferably 0 to 2°.

[0136] The liquid crystal cured layer is preferably an optically anisotropic layer, more preferably a positive A plate or a positive C plate, and even more preferably a positive A plate.

[0137] Here, a positive A plate (positive A plate) and a positive C plate (positive C plate) are defined as follows. When the refractive index in the in-plane slow axis direction of the film (the direction in which the in-plane refractive index is maximum) is nx, the refractive index in the in-plane direction perpendicular to the in-plane slow axis is ny, and the refractive index in the thickness direction is nz, a positive A plate satisfies the relationship of formula (A1), and a positive C plate satisfies the relationship of formula (C1). Note that a positive A plate has a positive Rth, and a positive C plate has a negative Rth. Formula (A1) nx>ny≒nz Formula (C1) nz>nx≒ny Note that the above "≒" encompasses not only the case where both are completely identical, but also the case where both are substantially identical. Regarding "substantially the same," for a positive A plate, "ny ≒ nz" includes, for example, a case where (ny - nz) x d (where d is the film thickness) is -10 to 10 nm, preferably -5 to 5 nm, and "nx ≒ nz" includes, for example, a case where (nx - nz) x d (where d is the film thickness) is -10 to 10 nm, preferably -5 to 5 nm. Also, for a positive C plate, "nx ≒ ny" includes, for example, a case where (nx - ny) x d (where d is the film thickness) is 0 to 10 nm, preferably 0 to 5 nm.

[0138] When the liquid crystal cured layer is a positive A plate, from the viewpoint of functioning as a λ / 4 plate, Re(550) is preferably 100 to 180 nm, more preferably 120 to 160 nm, even more preferably 130 to 150 nm, and particularly preferably 130 to 145 nm. Here, the "λ / 4 plate" is a plate having a λ / 4 function, specifically, a plate having a function of converting linearly polarized light of a certain wavelength into circularly polarized light (or circularly polarized light into linearly polarized light).

[0139] In the present invention, the thickness of the cured liquid crystal layer is not particularly limited, but is preferably 0.1 to 10 μm, more preferably 0.5 to 5 μm.

[0140] [Polarizing Plate] The polarizing plate of the present invention comprises the optical film of the present invention described above and a polarizer. Furthermore, when the liquid crystal cured layer described above is a λ / 4 plate (positive A plate), the polarizing plate of the present invention can be used as a circular polarizing plate. Furthermore, when the liquid crystal cured layer described above is a λ / 4 plate (positive A plate), the angle between the slow axis of the λ / 4 plate and the absorption axis of the polarizer described below is preferably 30 to 60°, more preferably 40 to 50°, even more preferably 42 to 48°, and particularly preferably 45°. Here, the "slow axis" of the λ / 4 plate refers to the direction in which the refractive index is maximized in the plane of the λ / 4 plate, and the "absorption axis" of the polarizer refers to the direction in which the absorbance is highest. Furthermore, the polarizing plate of the present invention can also be used as an optical compensation film for an IPS-type or FFS-type liquid crystal display device. When the polarizing plate of the present invention is used as an optical compensation film for an IPS-type or FFS-type liquid crystal display device, the above-mentioned liquid crystal cured layer can be at least one plate of a laminate of a positive A plate and a positive C plate, and is preferably the positive A plate. In this case, it is preferable that the angle between the slow axis of the positive A plate and the absorption axis of the polarizer described below is perpendicular or parallel. Specifically, it is more preferable that the angle between the slow axis of the positive A plate and the absorption axis of the polarizer described below is 0 to 5° or 85 to 95°. Furthermore, when the polarizing plate of the present invention is formed by laminating a polarizer, a positive C plate, and a positive A plate in this order, it is more preferable that the angle between the slow axis of the positive A plate and the absorption axis of the polarizer is parallel. Similarly, when the polarizing plate of the present invention is formed by laminating a polarizer, a positive A plate, and a positive C plate in this order, it is more preferable that the angle between the slow axis of the positive A plate and the absorption axis of the polarizer is perpendicular. When the polarizing plate of the present invention is used in a liquid crystal display device described later, the angle between the slow axis of the cured liquid crystal layer and the absorption axis of the polarizer described later is preferably parallel or perpendicular. In this specification, "parallel" does not require strict parallelism, but means that the angle between one axis and the other is less than 10°.Furthermore, in this specification, "orthogonal" does not require that they be strictly orthogonal, but rather means that the angle between one side and the other is greater than 80° and less than 100°.

[0141] [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.

[0142] In the present invention, the thickness of the polarizer is not particularly limited, but is preferably 3 μm to 60 μm, more preferably 5 μm to 30 μm, and even more preferably 5 μm to 15 μm.

[0143] [Adhesive Layer] The polarizing plate of the present invention may have an adhesive layer disposed between the liquid crystal cured layer in the optical film of the present invention and the polarizer. The adhesive layer used for laminating the liquid crystal cured layer 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.

[0144] [Image Display Device] The image display device of the present invention is an image display device having the optical film of the present invention or the polarizing plate of the present invention. The display element used in the image display device is not particularly limited, and examples thereof include a liquid crystal cell, an organic electroluminescence (hereinafter abbreviated as "EL (Electro Luminescence)") display panel, and a plasma display panel. Of these, a liquid crystal cell and an organic EL display panel are preferred, and a liquid crystal cell is more preferred. That is, as the image display device, a liquid crystal display device using a liquid crystal cell as the display element or an organic EL display device using an organic EL display panel as the display element is preferred, and a liquid crystal display device is more preferred.

[0145] [Liquid Crystal Display Device] A liquid crystal display device, which is an example of an image display device, is a liquid crystal display device having the above-described polarizing plate and a liquid crystal cell. Of the polarizing plates provided on both sides of the liquid crystal cell, it is preferable to use the above-described polarizing plate as the front-side polarizing plate, and it is more preferable to use the above-described polarizing plate as the front-side and rear-side polarizing plates. The liquid crystal cell constituting the liquid crystal display device will be described in detail below.

[0146] <Liquid Crystal Cell> The liquid crystal cell used in the liquid crystal display device is preferably, but not limited to, a VA (Vertical Alignment) mode, an OCB (Optically Compensated Bend) mode, an IPS (In-Plane-Switching) mode, an FFS (Fringe-Field-Switching) mode, or a TN (Twisted Nematic) mode. In a TN mode liquid crystal cell, when no voltage is applied, the rod-shaped liquid crystal molecules are aligned substantially horizontally and further twisted at an angle of 60 to 120 degrees. 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, the 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 Application Laid-Open No. 2006-215326 and Japanese Patent Application Laid-Open No. 2008-538819. In IPS-mode liquid crystal cells, rod-shaped liquid crystal molecules are aligned substantially parallel to the substrates, and the liquid crystal molecules respond in a planar manner when an electric field parallel to the substrate surface is applied. In IPS-mode cells, black is displayed when no electric field is applied, and the absorption axes of a pair of upper and lower polarizing plates are perpendicular to each other.Methods of using an optical compensation sheet to reduce light leakage in oblique directions during black display and improve the viewing angle are disclosed in JP-A Nos. 10-54982, 11-202323, 9-292522, 11-133408, 11-305217, and 10-307291.

[0147] [Organic EL Display Device] An example of an organic EL display device, which is an example of an image display device, includes, from the viewing side, a polarizer, a λ / 4 plate (positive A plate) made of the above-mentioned liquid crystal cured layer, and an organic EL display panel, in this order. The organic EL display panel is a display panel configured using organic EL elements in which an organic light-emitting layer (organic electroluminescence layer) is sandwiched between electrodes (between a cathode and an anode). The configuration of the organic EL display panel is not particularly limited, and a known configuration may be adopted.

[0148] 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.

[0149] [Example 1] [Preparation of Substrate 1] <Preparation of Core Layer Cellulose Acylate Dope 1> The following composition was charged into a mixing tank and stirred to dissolve each component, thereby preparing 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 Polyester below: 12 parts by mass Durability improver below: 4 parts by mass Methylene chloride (first solvent): 430 parts by mass Methanol (second solvent): 64 parts by mass

[0150] Polyester (number average molecular weight 800)

[0151] Durability improver

[0152] <Preparation of Outer Layer Cellulose Acylate Dope 1> 10 parts by mass of the following matting agent dispersion 1 was added to 90 parts by mass of the above core layer cellulose acylate dope 1 to prepare outer layer cellulose acylate dope 1. ---------------------------------------------------------------- Matting agent dispersion 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 1 part by mass

[0153] <Preparation of Substrate 1> The core layer cellulose acylate dope 1 and the outer layer cellulose acylate dope 1 were filtered using filter paper with an average pore size of 34 μm and a sintered metal filter with an average pore size of 10 μm. Then, using a band casting machine, the core layer cellulose acylate dope 1 and the outer layer cellulose acylate dopes 1 on both sides were simultaneously cast onto a drum at 20°C from the casting nozzle. The film was then peeled off from the drum while the solvent content of the film on the drum was approximately 20% by mass. Both ends of the resulting film in the width direction were fixed with tenter clips, and the film was stretched 1.1 times in the width direction while drying while the solvent content of the film was 3 to 15% by mass. The resulting film was then further dried by transporting it between the rolls of a heat treatment device to prepare a 40 μm-thick cellulose acylate film 1, which was used as Substrate 1. The retardation of Substrate 1 was measured, revealing Re = 1 nm and Rth = -5 nm.

[0154] [Production of Cured Liquid Crystal Layer 1] <Preparation of Composition 1 for Forming Alignment Film> Composition 1 for forming alignment film was prepared having the following composition. ---------------------------------------------------------------- Alignment Film Forming Composition 1 ---------------------------------------------------------------- Copolymer C1 (corresponding to polymer (I)) below: 90 parts by mass Copolymer C2 (corresponding to polymer (II)) below: 10 parts by mass Thermal Acid Generator D1 (below): 3.57 parts by mass Stabilizer DIPEA (below): 0.36 parts by mass Butyl acetate: 714 parts by mass Methyl ethyl ketone: 476 parts by mass

[0155] Copolymer C1

[0156] Copolymer C2

[0157] Thermal Acid Generator D1

[0158] Stabilizer DIPEA

[0159] <Preparation of Liquid Crystal Composition 1> A liquid crystal composition 1 for forming a cured liquid crystal layer having the following composition was prepared.

[0160] Liquid crystal composition 1 ------------------------------------------------ 27.00 parts by mass of liquid crystal compound R1 shown below 20.00 parts by mass of liquid crystal compound R2 shown below 20.00 parts by mass of liquid crystal compound R3 shown below 16.50 parts by mass of liquid crystal compound R4 shown below 16.50 parts by mass of liquid crystal compound R5 shown below 15.00 parts by mass of liquid crystal compound R6 shown below 3.00 parts by mass of additive M1 shown below 0.50 parts by mass of polymerization initiator S1 shown below 0.09 parts by mass of leveling agent P1 shown below 179.67 parts by mass of cyclopentanone 53.67 parts by mass of methyl ethyl ketone ------------------------------------------------

[0161] Liquid crystal compound R1 [Δn(450) / Δn(550): 0.58]

[0162] Liquid crystal compound R2 (in the following formula, t-Bu represents a tert-butyl group) [Δn(450) / Δn(550): 0.68]

[0163] 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)) [Δn(450) / Δn(550): 0.80]

[0164] Liquid crystal compound R4 [Δn(450) / Δn(550): 1.03]

[0165] Liquid crystal compound R5 [Δn(450) / Δn(550): 1.02]

[0166] Liquid crystal compound R6 [Δn(450) / Δn(550): 1.03]

[0167] Additive M1

[0168] Polymerization initiator S1

[0169] Leveling agent P1 (The numbers in the following formula indicate the content (% by mass) of each repeating unit relative to the total repeating units in leveling agent P1.)

[0170] <Preparation of Liquid Crystal Cured Layer 1> The previously prepared composition 1 for forming an alignment film was continuously applied to one side of the prepared substrate 1 using a bar coater. After application, the composition was dried in a heating zone at 120°C for 1 minute to remove the solvent, forming a photoisomerizable composition layer with a thickness of 0.3 µm. Subsequently, the layer was wound around a mirror-finished backup roll and irradiated with polarized ultraviolet light (10 mJ / cm ２ An alignment film was formed by applying a liquid crystal composition 1 prepared above using a bar coater onto the alignment film formed in a long shape, to form a composition layer. The temperature of the application chamber was set to 23°C. The formed composition layer was heated to 120°C in a heating zone and then cooled to 60°C. Thereafter, while maintaining the temperature, the layer was irradiated with ultraviolet light (300 mJ / cm) in a nitrogen atmosphere (oxygen concentration 100 ppm). ２ , using an ultra-high pressure mercury lamp) to fix the orientation, forming a liquid crystal cured layer 1 with a thickness of 2.2 μm, and producing an optical film. When the phase difference of the obtained liquid crystal cured layer 1 was measured, the in-plane retardation Re1(550) was 121 nm, and Re1(450) / Re1(550) was 0.69. When X-ray diffraction measurement was performed on the obtained liquid crystal cured layer 1 using the following equipment and conditions, diffracted light due to the order of the smectic phase was confirmed. (Equipment and conditions) X-ray diffraction equipment: ATXG (for thin film structure evaluation, manufactured by Rigaku Corporation) Cu beam source: 50 kV / 300 mA Soller slit: 0.45°

[0171] Examples 2 to 8 Optical films were produced in the same manner as in Example 1, except that the type and amount of copolymer contained in the composition for forming an alignment film 1 were changed to those shown in Table 1 below.

[0172] Example 9 An optical film was produced in the same manner as in Example 1, except that the liquid crystal composition 1 was replaced with a liquid crystal composition in which the liquid crystal compounds R1 and R3 to R6 were not blended and the blending amount of the liquid crystal compound R2 was changed to 100 parts by mass.

[0173] Examples 10 and 11 Optical films were produced in the same manner as in Example 1, except that the blending amount of the solvent contained in the composition 1 for forming an alignment film was changed to that shown in Table 1 below.

[0174] Example 12 An optical film was produced in the same manner as in Example 1, except that a liquid crystal composition containing 100 parts by mass of the following liquid crystal compound R7 was used instead of the liquid crystal composition 1, without blending any of the liquid crystal compounds R1 to R6.

[0175] Liquid crystal compound R7 [Δn(450) / Δn(550): 1.09]

[0176] Example 13 An optical film was produced in the same manner as in Example 1, except that the substrate 1 was replaced with a TAC film TG60 (manufactured by Fujifilm Corporation).

[0177] Example 14 An optical film was produced in the same manner as in Example 1, except that a liquid crystal composition containing 100 parts by mass of the following liquid crystal compound R8 without blending any of the liquid crystal compounds R1 to R6 was used instead of the liquid crystal composition 1.

[0178] Liquid crystal compound R8 [Δn(450) / Δn(550): 0.82]

[0179] Comparative Example 1 An optical film was produced in the same manner as in Example 1, except that a TAC film TG60 (manufactured by Fujifilm Corporation) was used instead of the substrate 1, and the amount of the solvent contained in the composition for forming an alignment film 1, and the type and amount of the copolymer were changed to those shown in Table 1 below.

[0180] Comparative Examples 2 and 3 Optical films were produced in the same manner as in Example 1, except that the substrate 1 was replaced with the same one as in Comparative Example 1 of JP 2014-164169 A, and the blending amount of the solvent, the type and blending amount of the copolymer contained in the composition for forming an alignment film 1 were changed to those shown in Table 1 below.

[0181] [Mixed Region] The thickness of the mixed region was measured by the method described above, and the results are shown in Table 1 below.

[0182] [Evaluation] The orientation and adhesion were evaluated as follows, and the results are shown in Table 1 below.

[0183] [Alignment] The alignment was measured by placing the LED light source, lower polarizing plate, sample (optical film), and upper polarizing plate on a table, from bottom to top, so that each surface was horizontal. The sample and upper polarizing plate were rotatable. The luminance of light emitted from the light source and transmitted through the lower polarizing plate, sample, and upper polarizing plate in this order was measured vertically using a luminance meter (BM-5A, manufactured by TOPCON). The measurement was first performed by rotating the upper polarizing plate in the absence of a sample to the position where the luminance was lowest (crossed Nicols). The prepared optical film was inserted between the polarizing plates, and the sample was rotated under crossed Nicols to measure the minimum luminance. Next, the upper and lower polarizing plates were arranged in a parallel Nicols configuration, and the sample was rotated to measure the maximum luminance. To eliminate the contribution of luminance leakage due to the upper and lower polarizing plates, the value calculated using the following formula was defined as the alignment of the optically anisotropic layer. Orientation = 1 / ((minimum luminance under crossed Nicols with a sample placed) / (maximum luminance under parallel Nicols with a sample placed)-(minimum luminance under crossed Nicols without a sample) / (maximum luminance under parallel Nicols without a sample)) (Evaluation criteria) A: The orientation is 200,000 or more B: The orientation is 100,000 or more and less than 200,000 C: The orientation is less than 100,000

[0184] [Adhesion] Tape was attached to the liquid crystal cured layer side of the prepared optical film and then peeled off. Components of the outermost 5 nm layer were analyzed by TOF-SIMS at any five points on the peeled optical film, and the results were evaluated according to the following criteria. (Evaluation criteria) A: No secondary ion components originating from the substrate were detected B: Secondary ion components originating from the substrate were detected at one point C: Secondary ion components originating from the substrate were detected at two or more points

[0185]

[0186] The structures of the copolymers in the compositions for forming alignment films in Table 1 are shown below.

[0187] Copolymer C1 (corresponding to polymer (I))

[0188] Copolymer C2 (corresponding to polymer (II))

[0189] Copolymer C3 (corresponding to polymer (II))

[0190] Copolymer C4 (corresponding to polymer (I))

[0191] Copolymer C5 (corresponding to polymer (I))

[0192] Copolymer C6 (corresponding to polymer (I))

[0193] From the results shown in Table 1, it was found that when the thickness of the mixed region in the substrate was 100 nm or less, the adhesion between the substrate and the alignment film was poor, regardless of whether polymer (I) was blended into the composition for forming an alignment film (Comparative Examples 1 and 2). Also, it was found that when the thickness of the mixed region in the substrate was 500 nm or more, the alignment of the cured liquid crystal layer was poor, even when polymer (I) was blended into the composition for forming an alignment film (Comparative Example 3).

[0194] In contrast, when the thickness of the mixed region in the substrate was greater than 100 nm and less than 500 nm, and polymer (I) was blended into the composition for forming an alignment film, it was found that the excellent alignment of the cured liquid crystal layer was maintained, and the adhesion between the substrate and the alignment film was good (Examples 1 to 14). In particular, a comparison of Examples 1 to 4 revealed that when the content a (mass%) of repeating unit A, the content b (mass%) of repeating unit B, and the content c (mass%) of repeating unit C in polymer (I) satisfied 5≦a≦30, 20≦b≦45, and 50≦c≦75, respectively, the alignment of the cured liquid crystal layer was improved, and the adhesion between the substrate and the alignment film was also improved. Furthermore, a comparison of Example 1 and Example 5 revealed that the alignment of the cured liquid crystal layer was improved when the composition for forming an alignment film further contained polymer (II). Furthermore, a comparison of Example 1 and Example 6 revealed that the alignment of the cured liquid crystal layer was improved when polymer (I) and polymer (II) satisfied formula (α). Furthermore, a comparison between Examples 1, 7, and 8 revealed that when the content of polymer (I) was 5 to 30% by mass relative to the total mass of polymer (I) and polymer (II), the alignment of the cured liquid crystal layer was improved, and the adhesion between the substrate and the alignment film was also improved. A comparison between Example 1 and Example 9 revealed that when the cured liquid crystal layer was a layer formed by fixing a smectic liquid crystal state, the alignment of the cured liquid crystal layer was improved. A comparison between Examples 1, 10, and 11 revealed that when the thickness of the mixed region in the substrate was more than 130 nm and less than 200 nm, the alignment of the cured liquid crystal layer was improved, and the adhesion between the substrate and the alignment film was also improved. A comparison between Example 1 and Example 12 revealed that the alignment of the cured liquid crystal layer was further improved when the liquid crystal compound used in the liquid crystal composition was a compound represented by formula (III), in which Ar in formula (III) represented any one of the aromatic rings selected from the group consisting of groups represented by formulas (Ar-1) to (Ar-5). Furthermore, a comparison between Example 1 and Example 13 revealed that when the retardation in the thickness direction of the substrate at a wavelength of 550 nm is more than −10 nm and less than 10 nm, the alignment of the cured liquid crystal layer becomes better.

[0195] 1 Substrate 2 Alignment film 3 Cured liquid crystal layer 4 Mixed region 5 Substrate region 10 Optical film d Thickness of mixed region C1 Results of secondary ion intensity derived from cured liquid crystal layer C2 Results of secondary ion intensity derived from polymer (I) C3 Results of secondary ion intensity derived from substrate

Claims

1. The material comprises a substrate, an alignment film provided on the substrate, and a liquid crystal curing layer provided on the alignment film. The orientation film is a photo-alignment film formed using an orientation film-forming composition containing a polymer (I) having a photo-aligning group and two or more different polymerizable groups. The substrate has a mixed region in the surface layer region on the orientation film side containing a component derived from the polymer (I), An optical film in which the thickness of the aforementioned mixed region is greater than 100 nm and less than 500 nm.

2. The optical film according to claim 1, wherein the polymer (I) is a copolymer having repeating unit A represented by the following formula (A), repeating unit B represented by the following formula (B), and repeating unit C represented by the following formula (C). 【Chemistry 1】 Here, in equations (A) to (C), R ａ ~R ｃ Each of these independently represents a hydrogen atom or a substituent. L ａ ~L ｃ Each of these independently represents a divalent linking group. A represents any photodirecting group selected from the group consisting of polyene group, stilbene group, stilbazole group, stilbazolium group, chalcone group, cinnamoyl group, aromatic Schiff base, aromatic hydrazone group, azobenzene group, azonaphthalene group, aromatic heterocyclic azo group, bisazo group, formazan group, azoxybenzene group, coumarin group, and maleimide group. B represents one of the polymerizable groups shown in the following formulas (PG-1) to (PG-3). C represents one of the polymerizable groups shown in the following formulas (PG-4) to (PG-9). 【Chemistry 2】 【Transformation 3】 Here, in the above formulas (PG-1) to (PG-9), * is L ｂ or L ｃ This indicates the connection point with [the other element]. R ｄ R represents a hydrogen atom, a halogen atom, a methyl group, an ethyl group, or a trifluoromethyl group. However, in the above formulas (PG-2), (PG-5), (PG-6), and (PG-9), multiple R ｄ These may be the same or different.

3. The optical film according to claim 2, wherein the mass percentages of the content a of the repeating unit A, the content b of the repeating unit B, and the content c of the repeating unit C, relative to the total mass of the polymer (I), satisfy 5 ≤ a ≤ 30, 20 ≤ b ≤ 45, and 50 ≤ c ≤ 75.

4. The optical film according to any one of claims 1 to 3, wherein the content of the polymer (I) is 5 to 30% by mass with respect to the total mass of the solid content of the orientation film forming composition.

5. The optical film according to any one of claims 1 to 3, wherein the orientation film forming composition further contains a polymer (II) which is not the polymer (I) and has repeating units B represented by the following formula (B). 【Chemistry 4】 Here, in formula (B), R ｂ represents a hydrogen atom or a substituent. L ｂ This represents a divalent linking group. B represents one of the polymerizable groups shown in the following formulas (PG-1) to (PG-3). 【Transformation 5】 Here, in the above formulas (PG-1) to (PG-3), * is L ｂ This indicates the connection point with [the other element]. R ｄ R represents a hydrogen atom, a halogen atom, a methyl group, an ethyl group, or a trifluoromethyl group. However, multiple R in the above formula (PG-2) ｄ These may be the same or different.

6. In the polymer (I), the dispersion force term of the Hansen solubility parameter is δD(I), the polarity term is δP(I), and the hydrogen bonding term is δH(I). In the polymer (II) described above, when the dispersion force term of the Hansen solubility parameter is δD(II), the polarity term is δP(II), and the hydrogen bonding term is δH(II), The optical film according to claim 5, satisfying the following formula (α). [Math 1]

7. The optical film according to claim 5, wherein the content of polymer (I) is 5 to 30% by mass relative to the total mass of polymer (I) and polymer (II).

8. The optical film according to any one of claims 1 to 3, wherein the liquid crystal curing layer is a layer in which the liquid crystal state of the smectic phase is fixed.

9. The optical film according to any one of claims 1 to 3, wherein the thickness of the mixed region is greater than 130 nm and less than 200 nm.

10. The aforementioned liquid crystal cured layer is a liquid crystal cured layer formed by fixing the orientation state of a liquid crystal composition containing a liquid crystal compound, The liquid crystal compound is a rod-shaped liquid crystal compound, The optical film according to any one of claims 1 to 3, wherein the refractive index difference Δn between the long axis and the short axis of the rod-shaped liquid crystal compound satisfies the following formula (β). Δn(450) / Δn(550)<1.0 (β) Here, in equation (β), Δn(450) represents the refractive index difference at 450 nm, and Δn(550) represents the refractive index difference at 550 nm.

11. The aforementioned liquid crystal cured layer is a liquid crystal cured layer formed by fixing the orientation state of a liquid crystal composition containing a liquid crystal compound, The optical film according to any one of claims 1 to 3, wherein the liquid crystal compound is a compound represented by the following formula (III). P １ -L １ -D ５ -(A １ ) ａ１ -D ３ -(G １ ) ｇ１ -D １ -〔Ar-D ２ 〕 ｑ１ -(G ２ ) ｇ２ -D ４ -(A ２ ) ａ２ -D ６ -L ２ -P ２ (III) Here, in equation (III), a1, a2, g1, and g2 each independently represent either 0 or 1, provided that at least one of a1 and g1 represents 1, and at least one of a2 and g2 represents 1. q1 represents either 1 or 2. D １ , D ２ , D ３ , D ４ , D ５ and D ６ These are, independently, single bonds, or -CO-, -O-, -S-, -C(=S)-, -CR １ R ２ -, -CR ３ =CR ４ -, -NR ５ -, or represents a divalent linking group consisting of two or more combinations thereof, R １ ~R ５ Each of these independently represents a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 12 carbon atoms. However, if q1 is 2, multiple D ２ These may be the same or different. G １ and G ２ Each of these independently represents an aromatic ring having 6 to 20 carbon atoms, which may have substituents, or a divalent alicyclic hydrocarbon group having 5 to 20 carbon atoms, which may have substituents, and the -CH group constituting the alicyclic hydrocarbon group ２ One or more of the hyphens may be replaced by -O-, -S-, or -NH-. A １ and A ２ Each of these independently represents an aromatic ring having 6 to 20 carbon atoms, which may have substituents, or a divalent alicyclic hydrocarbon group having 5 to 20 carbon atoms, which may have substituents, and the -CH group constituting the alicyclic hydrocarbon group ２ One or more of the hyphens may be replaced by -O-, -S-, or -NH-. L １ and L ２ Each of these independently represents a single bond or a divalent aliphatic hydrocarbon group having 1 to 20 carbon atoms. However, the -CH constituting the aliphatic hydrocarbon group is... ２ One or more of the hyphens may be substituted with -O-, -S-, -NH-, -N(Q)-, or -CO-, where Q represents a substituent. P １ and P ２ Each of these independently represents a monovalent organic group, P １ and P ２ At least one of them represents a polymerizable group. Ar represents an aromatic ring having 6 to 20 carbon atoms, which may have substituents, or a divalent alicyclic hydrocarbon group having 5 to 20 carbon atoms, which may have substituents, and the -CH group constituting the alicyclic hydrocarbon group ２ One or more of the hyphens may be replaced with -O-, -S-, or -NH-. However, if q1 is 2, the multiple Ars may be the same or different.

12. The optical film according to claim 11, wherein Ar in formula (III) represents any aromatic ring selected from the group consisting of groups represented by the following formulas (Ar-1) to (Ar-5). 【Transformation 6】 Here, in the above equations (Ar-1) to (Ar-5), * indicates the joining position. Q １ This represents N or CH. Q ２ is -S-, -O-, or -N(R ６ ) represents R ６ This represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. Y １ -CH represents an aromatic hydrocarbon group having 6 to 12 carbon atoms that may have substituents, an aromatic heterocyclic group having 3 to 12 carbon atoms that may have substituents, or an alicyclic hydrocarbon group having 6 to 20 carbon atoms that may have substituents, and the -CH constituting the alicyclic hydrocarbon group ２ One or more of the hyphens may be replaced by -O-, -S-, or -NH-. Z １ Z ２ and Z ３ These are, independently, 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, and -OR. ７ , -NR ８ R ９ ,-SR １０ , -COOR １１ , or -COR １２ Represents R ７ ~R １２ Each of these independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, Z １ and Z ２ These may combine with each other to form an aromatic ring. A ３ and A ４ These are, independently, -O- and -N(R) １３ R represents a group selected from the group consisting of -, -S-, and -CO-. １３ represents a hydrogen atom or substituent. X represents a nonmetallic atom belonging to groups 14 to 16. However, the nonmetallic atom may have a hydrogen atom or substituent bonded to it. D ７ and D ８ each independently represents a single bond or a divalent linking group consisting of -CO-, -O-, -S-, -C(=S)-, -CR １ R ２ -, -CR ３ =CR ４ -, -NR ５ -, or a combination of two or more of these, and R １ ~R ５ each independently represents a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 12 carbon atoms. L ３ and L ４ Each of these independently represents a single bond or a divalent aliphatic hydrocarbon group having 1 to 20 carbon atoms. However, the -CH constituting the aliphatic hydrocarbon group is... ２ One or more of the hyphens may be substituted with -O-, -S-, -NH-, -N(Q)-, or -CO-, where Q represents a substituent. P ３ and P ４ each independently represents a monovalent organic group, and at least one of P ３ and P ４ represents a polymerizable group. Ax represents an organic group having 2 to 30 carbon atoms and having at least one aromatic ring selected from the group consisting of aromatic hydrocarbon rings and aromatic heterocycles. Ay represents an organic group having 2 to 30 carbon atoms, having a hydrogen atom, an alkyl group having 1 to 12 carbon atoms which may have substituents, or at least one aromatic ring selected from the group consisting of aromatic hydrocarbon rings and aromatic heterocycles. The aromatic rings in Ax and Ay may have substituents, and Ax and Ay may be bonded together to form a ring. Q ３ This represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, which may have substituents.

13. The optical film according to any one of claims 1 to 3, wherein the retardation of the substrate in the thickness direction at a wavelength of 550 nm is greater than -10 nm and less than 10 nm.

14. A polarizing plate comprising an optical film according to any one of claims 1 to 3 and a polarizer.

15. An image display device having an optical film according to any one of claims 1 to 3.

16. The image display device according to claim 15, which is a liquid crystal display device.

17. The image display device according to claim 15, which is an organic EL display device.

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