WO2025205556A1 - Liquid crystal composition, optically anisotropic film, optical film, polarizing plate, and image display device - Google Patents

Abstract

The present invention addresses the problem of providing: a liquid crystal composition that is used in the formation of an optically anisotropic film having good alignment properties and durability; an optically anisotropic film; an optical film; a polarizing plate; and an image display device. A liquid crystal composition according to the present invention comprises a polymerizable liquid crystal compound represented by formula (1) and an alignment aid, wherein the boiling point of the alignment aid is higher than 250°C but not higher than 350°C, and there is a distance of 4-20 between the Hansen solubility parameter of the alignment aid and the Hansen solubility parameter of at least one of the compounds represented by formulae (T1) and (T2), which correspond to a substructure of the polymerizable liquid crystal compound represented by L¹-SP¹- and a substructure of the polymerizable liquid crystal compound represented by L²-SP²- in formula (1).

Description

Liquid crystal composition, optically anisotropic film, optical film, polarizing plate and image display device

The present invention relates to a liquid crystal composition, an optically anisotropic film, an optical film, a polarizing plate, and an image display device.

Polymerizable compounds that exhibit reverse wavelength dispersion are being actively researched because they have the following characteristics: they enable accurate conversion of light wavelengths over a wide wavelength range; and they have a high refractive index, which allows for the formation of thinner retardation films.
Furthermore, polymerizable compounds exhibiting reverse wavelength dispersion generally follow a T-type molecular design guideline, which requires that the wavelength of the long axis of the molecule be made shorter and the wavelength of the short axis located at the center of the molecule be made longer.
For this reason, it is known that a cycloalkylene skeleton with no absorption wavelength is used to connect the skeleton of the short axis located at the center of the molecule (hereinafter also referred to as the "reverse wavelength dispersion producing part") to the long axis of the molecule.
For example, Patent Document 1 describes a polymerizable composition containing a polymerizable compound having two or more reverse wavelength dispersion generating moieties and a polymerizable compound having two or more polymerizable groups ([Claim 1], [Claim 9], etc.).

Japanese Patent Application Laid-Open No. 2019-011467

The present inventors studied the polymerizable composition (liquid crystal composition) described in Patent Document 1 and found that when an alignment aid was added to lower the alignment temperature, the alignment of the optically anisotropic film formed deteriorated or its durability deteriorated, depending on the type of alignment aid.

The present invention therefore aims to provide a liquid crystal composition that can be used to form an optically anisotropic film that has both good alignment properties and durability, as well as an optically anisotropic film, an optical film, a polarizing plate, and an image display device.

As a result of intensive research to achieve the above object, the present inventors have found that by using a liquid crystal composition containing an alignment aid having a boiling point of more than 250°C and not more than 350°C, and in which the distance between a predetermined partial structure in a polymerizable liquid crystal compound and the Hansen solubility parameter of the corresponding compound is a predetermined value, both the alignment property and durability of the formed optically anisotropic film can be improved, and have completed the present invention.
That is, the present inventors have found that the above problems can be solved by the following configuration.

[1] A polymerizable liquid crystal compound represented by formula (1) described later and an alignment aid are contained,
The boiling point of the alignment aid is higher than 250°C and not higher than 350°C,
A liquid crystal composition, wherein the distance between the Hansen solubility parameter of at least one of compounds represented by formulas (T1) and (T2) described later, which correspond to the partial structure represented by L ¹ -SP ¹ - and the partial structure represented by L ² -SP ² - in formula (1) described later in the polymerizable liquid crystal compound, and the Hansen solubility parameter of the alignment aid is 4 to 20.
[2] The liquid crystal composition according to [1], wherein the alignment assistant has a molecular weight of 500 or less.
[3] The liquid crystal composition according to [1] or [2], wherein the alignment aid is a compound represented by formula (2-1) or (2-2) described below.
Q represents a substituent.
[4] An optically anisotropic film obtained by fixing the alignment state of the liquid crystal composition according to any one of [1] to [3].
[5] The optically anisotropic film according to [4], wherein the content of the alignment aid is 10% by mass or less relative to the mass of the optically anisotropic film.
[6] An optical film having the optically anisotropic film according to [4] or [5].
[7] A polarizing plate comprising the optical film according to [6] and a polarizer.
[8] An image display device comprising the optical film according to [6] or the polarizing plate according to [7], and a display element.

The present invention provides a liquid crystal composition used to form an optically anisotropic film that has both good alignment properties and durability, as well as an optically anisotropic film, an optical film, a polarizing plate, and an image display device.

FIG. 1 is a schematic cross-sectional view showing an example of the optical film of the present invention. FIG. 2 is a schematic cross-sectional view showing an example of the optical film of the present invention. FIG. 3 is a schematic cross-sectional view showing an example of the optical film of the present invention.

The present invention will be described in detail below.
The following description of the components may be based on typical embodiments of the present invention, but the present invention is not limited to such embodiments.
In this specification, a numerical range expressed using "to" means a range that includes the numerical values before and after "to" as the lower and upper limits.
In addition, in the present specification, in the numerical ranges described in stages, the upper or lower limit value described in a certain numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. Furthermore, in the numerical ranges described in the present specification, the upper or lower limit value described in a certain numerical range may be replaced with a value shown in the examples.
In addition, in this specification, each component may be a single substance corresponding to the component, or two or more substances may be used in combination. Here, when two or more substances are used in combination for each component, the content of the 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".
Furthermore, the bonding direction of a divalent group (for example, -O-CO-) represented in this specification is not particularly limited. For example, when ^L2 is -O-CO- in the bond of " ^L1 - ^L2 - ^L3 ", if the position bonding to the ^L1 side is *1 and the position bonding to the ^L3 side is *2, ^L2 may be *1-O-CO-*2 or *1-CO-O-*2.

In this specification, Re(λ) and Rth(λ) respectively represent the in-plane retardation and the thickness retardation at a wavelength λ, which is 550 nm unless otherwise specified.
In the present invention, Re(λ) and Rth(λ) are values measured at a wavelength of λ using an AxoScan (manufactured by Axometrics).
Specifically, by inputting the average refractive index ((nx+ny+nz)/3) and film thickness (d) into AxoScan,
Slow axis direction (°)
Re(λ)=R0(λ)
Rth(λ)=((nx+ny)/2-nz)×d
is calculated.
Note that R0(λ) is displayed as a numerical value calculated by AxoScan, but it means Re(λ).

In addition, in this specification, examples of the substituent (monovalent substituent) include the substituents described in the following Substituent Group A.
In this specification, the phrase "optionally substituted" includes not only embodiments in which no substituent is present, but also embodiments in which one or more substituents are present.
<Substituent group A>
Examples of the substituent include:
a halogen atom (e.g., a fluorine atom, a chlorine atom, or a bromine atom, preferably a chlorine atom or a fluorine atom, more preferably a fluorine atom);
alkyl groups (preferably having 1 to 48 carbon atoms, more preferably having 1 to 24 carbon atoms, and particularly preferably having 1 to 8 carbon atoms, which are linear, branched, or cyclic alkyl groups, for example, linear alkyl groups having 1 to 6 carbon atoms (e.g., methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl), branched alkyl groups having 3 to 6 carbon atoms (e.g., isopropyl, isobutyl, tert-butyl, sec-butyl, neopentyl, isohexyl, 3-methylpentyl), and cyclic alkyl groups having 3 to 12 carbon atoms (e.g., cyclopropyl, cyclopentyl, cyclohexyl, 1-norbornyl, 1-adamantyl));
an alkenyl group (preferably an alkenyl group having 2 to 48 carbon atoms, more preferably 2 to 18 carbon atoms, for example, a vinyl group, an allyl group, a 1-butenyl group, or a 2-butenyl group);
an alkynyl group (preferably an alkynyl group having 2 to 6 carbon atoms, more preferably 2 to 4 carbon atoms, for example, an ethynyl group, a 1-propynyl group, a propargyl group, a 1-butynyl group, or a 2-butynyl group);
an aryl group (preferably an aryl group having 6 to 48 carbon atoms, more preferably 6 to 24 carbon atoms, such as a phenyl group, an oligoaryl group (a naphthyl group, an anthryl group), a phenanthrenyl group, a fluorenyl group, a pyrenyl group, a triphenylenyl group, or a biphenyl group);
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);
an arylalkyl group (preferably an arylalkyl group having 7 to 15 carbon atoms, for example, a benzyl group, a phenethyl group, a methylbenzyl group, a phenylpropyl group, a 1-methylphenylethyl group, a phenylbutyl group, a 2-methylphenylpropyl group, a tetrahydronaphthyl group, a naphthylmethyl group, a naphthylethyl group, an indenyl group, a fluorenyl group, an anthracenylmethyl group (anthrylmethyl group), or a phenanthrenylmethyl group (phenanthrylmethyl group));
a silyl group (preferably a silyl group having 3 to 38 carbon atoms, more preferably 3 to 18 carbon atoms, for example, a trimethylsilyl group, a triethylsilyl group, a tributylsilyl group, a t-butyldimethylsilyl group, or a t-hexyldimethylsilyl group);
Hydroxy group; cyano group; nitro group; morpholino group;
an alkoxy group (preferably an alkoxy group having 1 to 48 carbon atoms, more preferably 1 to 24 carbon atoms, for example, a methoxy group, an ethoxy group, a 1-butoxy group, a 2-butoxy group, an isopropoxy group, a t-butoxy group, a dodecyloxy group, or a cycloalkyloxy group (for example, a cyclopentyloxy group, a cyclohexyloxy group));
an aryloxy group (preferably an aryloxy group having 6 to 48 carbon atoms, more preferably 6 to 24 carbon atoms, for example, a phenoxy group or a 1-naphthoxy group);
an alkenyloxy group (preferably an alkenyloxy group having 2 to 6 carbon atoms, for example, a vinyloxy group, a 1-propenyloxy group, a 2-n-propenyloxy group (allyloxy group), a 1-n-butenyloxy group, or a prenyloxy group);
heterocyclic oxy groups (preferably heterocyclic oxy groups having 1 to 32 carbon atoms, more preferably 1 to 18 carbon atoms, for example, a 1-phenyltetrazol-5-oxy group or a 2-tetrahydropyranyloxy group);
a silyloxy group (preferably a silyloxy group having 1 to 32 carbon atoms, more preferably 1 to 18 carbon atoms, for example, a trimethylsilyloxy group, a t-butyldimethylsilyloxy group, or a diphenylmethylsilyloxy group);
an acyloxy group (preferably an acyloxy group having 2 to 48 carbon atoms, more preferably 2 to 24 carbon atoms, for example, an acetoxy group, a pivaloyloxy group, a benzoyloxy group, a dodecanoyloxy group, an acryloyloxy group, or a methacryloyloxy group);
a hydroxyalkyleneoxy group (preferably a hydroxyalkyleneoxy group having 2 to 10 carbon atoms, for example, a hydroxyethyleneoxy group);
an alkoxycarbonyloxy group (preferably an alkoxycarbonyloxy group 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));
an aryloxycarbonyloxy group (preferably an aryloxycarbonyloxy group having 7 to 32 carbon atoms, more preferably 7 to 24 carbon atoms, for example, a phenoxycarbonyloxy group);
a carbamoyloxy group (preferably a carbamoyloxy group 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);
a sulfamoyloxy group (preferably a sulfamoyloxy group having 1 to 32 carbon atoms, more preferably 1 to 24 carbon atoms, for example, an N,N-diethylsulfamoyloxy group, an N-propylsulfamoyloxy group);
an alkylsulfonyloxy group (preferably an alkylsulfonyloxy group having 1 to 38 carbon atoms, more preferably 1 to 24 carbon atoms, for example, a methylsulfonyloxy group, a hexadecylsulfonyloxy group, or a cyclohexylsulfonyloxy group);
an arylsulfonyloxy group (preferably an arylsulfonyloxy group having 6 to 32 carbon atoms, more preferably 6 to 24 carbon atoms, for example, a phenylsulfonyloxy group);
acyl groups (preferably acyl groups having 1 to 48 carbon atoms, more preferably 1 to 24 carbon atoms, such as formyl, acetyl, acryloyl, methacryloyl, pivaloyl, benzoyl, tetradecanoyl, and cyclohexanoyl groups);
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, for example, a phenoxycarbonyl group);
a carbamoyl group (preferably a carbamoyl group having 1 to 48 carbon atoms, more preferably 1 to 24 carbon atoms, for example, a carbamoyl group, an N,N-diethylcarbamoyl group, an N-ethyl-N-octylcarbamoyl group, an N,N-dibutylcarbamoyl group, an N-propylcarbamoyl group, an N-phenylcarbamoyl group, an N-methyl-N-phenylcarbamoyl group, or an N,N-dicyclohexylcarbamoyl group);
an amino group (preferably an amino group having 32 or less carbon atoms, more preferably 24 or less carbon atoms, for example, an amino group, a methylamino group, an N,N-dibutylamino group, a tetradecylamino group, a 2-ethylhexylamino group, or a cyclohexylamino group);
an anilino group (preferably an anilino group having 6 to 32 carbon atoms, more preferably 6 to 24 carbon atoms, for example, an anilino group or an N-methylanilino group);
a 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);
a carbonamido group (preferably a carbonamido group having 2 to 48 carbon atoms, more preferably 2 to 24 carbon atoms, such as an acetamido group, a benzamido group, a tetradecaneamido group, a pivaloylamido group, or a cyclohexanamido group);
a 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, or an N-phenylureido group);
an 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 or 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);
a sulfonamide group (preferably a sulfonamide group having 1 to 48 carbon atoms, more preferably 1 to 24 carbon atoms, for example, a methanesulfonamide group, a butanesulfonamide group, a benzenesulfonamide group, a hexadecanesulfonamide group, or a cyclohexanesulfonamide group);
a sulfamoylamino group (preferably a sulfamoylamino group having 1 to 48 carbon atoms, more preferably 1 to 24 carbon atoms, for example, an N,N-dipropylsulfamoylamino group or an N-ethyl-N-dodecylsulfamoylamino group);
an azo group (preferably an azo group having 1 to 32 carbon atoms, more preferably 1 to 24 carbon atoms, for example, a phenylazo group or a 3-pyrazolylazo group);
an alkylthio group (preferably an alkylthio group having 1 to 48 carbon atoms, more preferably 1 to 24 carbon atoms, for example, a methylthio group, an ethylthio group, an octylthio group, or a cyclohexylthio group);
an arylthio group (preferably an arylthio group having 6 to 48 carbon atoms, more preferably 6 to 24 carbon atoms, for example, a phenylthio group);
heterocyclic thio groups (preferably heterocyclic thio groups having 1 to 32 carbon atoms, more preferably 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 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 6 to 24 carbon atoms, for example, a phenylsulfinyl group);
an alkylsulfonyl group (preferably an alkylsulfonyl group having 1 to 48 carbon atoms, more preferably 1 to 24 carbon atoms, for example, a methylsulfonyl group, an ethylsulfonyl group, a propylsulfonyl group, a butylsulfonyl group, an isopropylsulfonyl group, a 2-ethylhexylsulfonyl group, a hexadecylsulfonyl group, an octylsulfonyl group, or a cyclohexylsulfonyl group);
an arylsulfonyl group (preferably an arylsulfonyl group having 6 to 48 carbon atoms, more preferably 6 to 24 carbon atoms, for example, a phenylsulfonyl group or a 1-naphthylsulfonyl group);
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);
a phosphonyl group (preferably a phosphonyl group 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);
a phosphinoylamino group (preferably a phosphinoylamino group having 1 to 32 carbon atoms, more preferably 1 to 24 carbon atoms, for example, a diethoxyphosphinoylamino group or a dioctyloxyphosphinoylamino group);
_{Epoxy group ; -NHCOCH3} ; _{-SO2NHC2H4OCH3} ; _{-NHSO2CH3 ;}
These may be combined in two or more ways.
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.

[Liquid Crystal Composition]
The liquid crystal composition of the present invention is a liquid crystal composition containing a polymerizable liquid crystal compound represented by formula (1) described below (hereinafter also abbreviated as "specific polymerizable liquid crystal compound") and an alignment aid.
In the liquid crystal composition of the present invention, the boiling point of the alignment aid is higher than 250°C and not higher than 350°C.
Furthermore, in the liquid crystal composition of the present invention, the distance between the Hansen solubility parameters (hereinafter also abbreviated as "HSP") of at least one of the compounds represented by formulas (T1) and (T2) described later, which correspond to the partial structure represented by L ¹ -SP ¹ - and the partial structure represented by L ² -SP ² - in formula (1) described later in the specific polymerizable liquid crystal compound (hereinafter also abbreviated as "corresponding compound T"), and the Hansen solubility parameter of the alignment aid (hereinafter also abbreviated as "HSP distance between the SPL end of the specific polymerizable liquid crystal compound and the alignment aid") is 4 to 20.
Note that the corresponding compound T is a compound used to calculate the HSP distance with the alignment aid, and is therefore not an essential component contained in the liquid crystal composition of the present invention.

Here, the Hansen Solubility Parameter (HSP) divides the solubility of a substance into three components (dispersion term δd, polar term δp, and hydrogen bonding term δh) and expresses it in three-dimensional space. The dispersion term δd indicates the effect of dispersion forces, the polar term δp indicates the effect of dipole-dipole forces, and the hydrogen bonding term δh indicates the effect of hydrogen bonding forces.
In the present invention, the Hansen solubility parameter is a value calculated by inputting the structural formula of a compound into HSPiP (Ver. 5.1.08).
In the present invention, the HSP distance between the SPL terminal of the specific polymerizable liquid crystal compound and the alignment aid can be calculated as Ra by introducing δd, δp, and δh calculated for each component into the following formula: In the following formula, δd1, δp1, and δh1 are values calculated from the alignment aid, and δd2, δp2, and δh2 are values calculated from the corresponding compound T.

In the present invention, by using a liquid crystal composition containing a specific polymerizable liquid crystal compound and an alignment aid, in which the boiling point of the alignment aid is higher than 250°C and not higher than 350°C, and the HSP distance between the SPL terminal of the specific polymerizable liquid crystal compound and the alignment aid is 4 to 20, both the alignment property and durability of the formed optically anisotropic film are improved.
The reason why this effect is exhibited is not clear in detail, but the present inventors speculate as follows.
First, since the HSP distance between the SPL terminal of the specific polymerizable liquid crystal compound and the alignment aid is 4 to 20, the alignment aid is more likely to interact with the reverse wavelength dispersion-expressing portion and mesogenic portion of the specific polymerizable liquid crystal compound rather than with the terminal structure of the specific polymerizable liquid crystal compound, which is thought to have made it possible to lower the alignment temperature while suppressing a decrease in liquid crystallinity.
On the other hand, the inventors speculate that one of the reasons for the poor durability of the formed optically anisotropic film is that the large amount of residual alignment aid in the optically anisotropic film promotes the penetration of water into the optically anisotropic film due to the alignment aid and the relaxation of the alignment of the liquid crystal compound over time, thereby worsening durability.
Furthermore, since the boiling point of the alignment aid is above 250°C, it is possible to allow sufficient amount of alignment aid to remain in the system when aligning the specific polymerizable liquid crystal compound (especially in the initial stage of alignment), which is thought to have improved alignment.
Furthermore, since the boiling point of the alignment aid is 350°C or less, after the specific polymerizable liquid crystal compound is aligned, the alignment aid volatilizes due to heating during the alignment treatment, reducing its content, which is thought to have improved durability.

In the present invention, the HSP distance between the SPL end of the specific polymerizable liquid crystal compound and the alignment aid is preferably 4 to 18, more preferably 4 to 16, and even more preferably 4 to 15, because this improves both the alignment and durability of the optically anisotropic film that is formed.

The specific polymerizable liquid crystal compound, alignment aid, and optional components contained in the liquid crystal composition of the present invention are described in detail below.

[Specific polymerizable liquid crystal compound]
The specific polymerizable liquid crystal compound contained in the liquid crystal composition of the present invention is a compound represented by the following formula (1).

In the above formula (1), D ¹ , D ² , D ³ and D ⁴ each independently represent a single bond, or -CO-, -O-, -S-, -C(═S)-, -CR ¹ R ² -, -CR ³ ═CR ⁴ -, -NR ⁵ -, or a divalent linking group consisting of a combination of two or more of these, and R ¹ to R ⁵ each independently represent a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 12 carbon atoms.
Furthermore, ^G1 represents ^AG or SP ^G.
Furthermore, A ¹ , A ² and A ^G each independently represent an aromatic hydrocarbon ring which may have a substituent, an aromatic heterocycle which may have a substituent, or a divalent alicyclic hydrocarbon group which may have a substituent, provided that one or more of the -CH ₂ - groups constituting the alicyclic hydrocarbon group may be substituted with -O-, -S- or -NH-.
Furthermore, SP ¹ , SP ² and SP ^G each independently represent a single bond or a divalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, provided that one or more of the -CH ₂ - groups constituting the aliphatic hydrocarbon group may be substituted with -O-, -S-, -NH-, -N(Q)- or -CO-. Q represents a substituent.
Furthermore, ^L1 and ^L2 each independently represent a monovalent organic group, and at least one of ^L1 and ^L2 represents a polymerizable group, provided that when at least one of ^Ar1 and ^Ar2 is an aromatic ring represented by the following formula (Ar-4), at least one of L1 and ^L2 and ^L3 and ^L4 in the following formula (Ar- ⁴ ) represents a polymerizable group.
Furthermore, m represents an integer of 0 to 2, and when m is 2, the plurality of G ^1s may be the same or different, and the plurality of D ^1s may be the same or different.
Furthermore, l and n each independently represent 0 or an integer of 1 or more, and when l is an integer of 2 or more, multiple A ¹ 's may be the same or different, and multiple D ³ 's may be the same or different, and when n is an integer of 2 or more, multiple D ⁴ 's may be the same or different, and multiple A ² 's may be the same or different.
Furthermore, p represents an integer of 1 to 3. When p is 2 or 3, multiple Ar ¹ 's may be the same or different from each other, and multiple D ² 's may be the same or different from each other, and when p is 2 or 3 and m is not 0, multiple G ¹ 's may be the same or different from each other, and multiple D ¹ 's may be the same or different from each other.

In the above formula (1), examples of the divalent linking group represented by one embodiment of D ¹ , D ² , D ³ and D ⁴ include, for example, —CO—, —O—, —CO—O—, —C(═S)O—, —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 —, —NR ⁵ —CR ¹ R ² —, and —CO—NR ⁵ R ¹ , R ² and R ⁵ each independently represent a hydrogen atom, a fluorine atom or an alkyl group having 1 to 12 carbon atoms.
D ¹ , D ² , D ³ and D ⁴ are preferably any of a single bond, —CO—, —O— and —CO—O—.

In the above formula (1), examples of the aromatic hydrocarbon ring represented by one embodiment of A ¹ , A ² and A ^G (A ^G as one embodiment of G ¹ ; the same applies hereinafter) include aromatic hydrocarbon rings having 6 to 20 carbon atoms, and specific examples include a benzene ring, a naphthalene ring, an anthracene ring, and a phenanthroline ring.
Furthermore, examples of the aromatic heterocycle represented by one embodiment of A ¹ , A ² and A ^G include aromatic heterocycles having 5 to 20 carbon atoms, and specific examples thereof include a furan ring, a pyrrole ring, a thiophene ring, a pyridine ring, a thiazole ring, and a benzothiazole ring.
Furthermore, the divalent alicyclic hydrocarbon group represented by one embodiment of A ¹ , A ² , and A ^G is preferably a 5- or 6-membered ring. The divalent alicyclic hydrocarbon group may be saturated or unsaturated, but is preferably a divalent saturated alicyclic hydrocarbon group. One or more of the -CH ₂ - groups constituting the divalent alicyclic hydrocarbon group may be substituted with -O-, -S-, or -NH-. Examples of such divalent alicyclic hydrocarbon groups include divalent alicyclic hydrocarbon groups having 5 to 12 carbon atoms, specific examples of which include monocyclic hydrocarbon groups and bridged cyclic hydrocarbon groups, and more specific examples of which include those represented by the following formulas (g-1) to (g-10):

In addition, in the above formula (1), with respect to A ¹ , A ² and A ^G , examples of the substituent that the aromatic hydrocarbon ring, aromatic heterocycle or divalent alicyclic hydrocarbon group 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 preferred.

In the above formula (1), examples of the divalent aliphatic hydrocarbon group having 1 to 20 carbon atoms represented by one embodiment of SP ¹ , SP ² and SP ^G (SP ^G as one embodiment of G ¹ ; the same applies hereinafter) include a linear alkylene group having 1 to 20 carbon atoms or a branched alkylene group having 3 to 20 carbon atoms, a linear alkenylene group having 1 to 20 carbon atoms or a branched alkynylene group having 1 to 20 carbon atoms, or a branched alkynylene group having 3 to 20 carbon atoms.
As the linear alkylene group having 1 to 20 carbon atoms or the branched alkylene group having 3 to 20 carbon atoms, an alkylene group having 1 to 12 carbon atoms is preferable, and an alkylene group having 1 to 10 carbon atoms is more preferable. Suitable examples thereof include a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, and a hexylene group.
As the linear alkenylene group having 1 to 20 carbon atoms or the branched alkenylene group having 3 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 a suitable example thereof is an ethenylene group.
As the linear alkynylene group having 1 to 20 carbon atoms or the branched alkynylene group having 3 to 20 carbon atoms, an alkynylene group having 2 to 10 carbon atoms is preferred, and an alkynylene group having 2 to 4 carbon atoms is more preferred, and a suitable example thereof is an ethynylene group.
As described above, in SP ¹ , SP ² and SP ^G , one or more of the -CH ₂ - groups constituting the aliphatic hydrocarbon group may be substituted with -O-, -S-, -NH-, -N(Q)- or -CO-, and examples of the substituent represented by Q include the substituents described in the above-mentioned substituent group A, and among these, an alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group or a halogen atom is preferred.

In the present invention, from the viewpoint of facilitating the development of liquid crystallinity, G ¹ in the above formula (1) is preferably A 2 G out of the ^above -mentioned A 2 ^G and ^SPG .
Furthermore, for reasons of improving the reverse wavelength dispersion and improving the solubility, it is preferable that G ¹ in the above formula (1) represents a cycloalkane ring or a cycloalkene ring.
Specific examples of the cycloalkane ring include a cyclohexane ring, a cycloheptane ring, a cyclooctane ring, a cyclododecane ring, and a cyclodocosane ring.
Specific examples of the cycloalkene ring include a cyclobutene ring, a cyclopentene ring, a cyclohexene ring, a cycloheptene ring, a cyclooctene ring, a cyclopentadiene ring, and a cyclohexadiene ring.

In the above formula (1), examples of the monovalent organic group represented by ^L1 and ^L2 include an alkyl group, an aryl group, a heteroaryl group, an alkoxy group, a cyano group, and a carboxy group. The alkyl group may be linear, branched, or cyclic, but is preferably linear. 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 is preferably monocyclic. 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.

In the above formula (1), the polymerizable group represented by at least one of L ¹ and L ² is not particularly limited, but is preferably a polymerizable group capable of radical polymerization or cation polymerization.
As the radical polymerizable group, a known radical polymerizable group can be used, and preferred examples include an acryloyloxy group or a methacryloyloxy group. In this case, it is known that the polymerization rate of the acryloyloxy group is generally fast, and from the viewpoint of improving productivity, the 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 thereof 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 them, 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 formulae (P-1) to (P-20): In the following formulae, Me represents a methyl group, and Et represents an ethyl group.

In the present invention, for the reason that the durability of the optically anisotropic film to be formed is improved, it is preferable that ^L1 and ^L2 in the above formula (1) are both polymerizable groups, and more preferably an acryloyloxy group or a methacryloyloxy group.

In the above formula (1), m represents an integer of 0 to 2; l and n each independently represent an integer of 0 or 1 or more; and p represents an integer of 1 to 3.
Here, m is preferably 0 or 1, and more preferably 1 from the viewpoint of synthesis.
It is preferable that l and n are integers of 0 to 2 from the viewpoint of solubility and compatibility with other liquid crystal compounds.
p is preferably 1 or 2, and more preferably 1.

In the present invention, it is preferable that both l and n in the above formula (1) represent 1 and both ^A1 and ^A2 represent a benzene ring, because liquid crystallinity is easily exhibited over a wide temperature range including room temperature and the birefringence (Δn) is also large.

Meanwhile, in the above formula (1), Ar ¹ and Ar ² each independently represent any aromatic ring selected from the group consisting of groups represented by the following formulae (Ar-1) to (Ar-8). In the following formulae (Ar-1) to (Ar-8), *1 represents the bonding position with D ³ or D ⁴ , and *2 represents the bonding position with D ¹ or D ^2. However, when l is 0, the bonding position with D ³ represents the bonding position with SP ¹ , when m is 0, *2 represents the bonding position with D ² , and when n is 0, the bonding position with D ⁴ represents the bonding position with SP ² .

In the above formulas (Ar-1) and (Ar-2), ^Q1 represents N or CH, ^Q2 represents -S-, -O-, or -N( ^R6 )-, ^R6 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and ^Y1 represents a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms which may have a substituent, a monovalent aromatic heterocyclic group having 3 to 12 carbon atoms which may have a substituent, or a monovalent alicyclic hydrocarbon group having 6 to 20 carbon atoms which may have a substituent, and one or more of the _-CH2- groups constituting the alicyclic hydrocarbon group may be substituted with -O-, -S-, or -NH-.
Specific examples of the alkyl group having 1 to 6 carbon atoms represented by one embodiment of R ⁶ 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 monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms represented by one embodiment of Y ¹ include aryl groups such as a phenyl group, a 2,6-diethylphenyl group, and a naphthyl group.
Examples of the monovalent aromatic heterocyclic group having 3 to 12 carbon atoms represented by one embodiment of Y ¹ include heteroaryl groups such as a thienyl group, a thiazolyl group, a furyl group, and a pyridyl group, as well as groups formed 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. Of these, the aromatic heterocyclic group having 3 to 12 carbon atoms represented by Y ¹ is preferably a group formed by removing one hydrogen atom from a benzofuran ring or a benzothiazole ring.
Examples of the monovalent alicyclic hydrocarbon group having 6 to 20 carbon atoms represented by one embodiment of Y ¹ include a cyclohexyl group, a cyclopentyl group, a norbornyl group, and an adamantyl group.
In addition, examples of the substituent that Y ¹ 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.

In the above formulas (Ar-1) to (Ar-8), Z ¹ , Z ² and Z ³ each independently represent 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 , where R ⁷ to R ¹² each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and 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 preferable, an alkyl group having 1 to 8 carbon atoms is more preferable, 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-dimethylbutyl group is further preferable, and a methyl group, an ethyl group, or a tert-butyl group is particularly preferable.
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; monocyclic unsaturated hydrocarbon groups such as cyclobutenyl, cyclopentenyl, cyclohexenyl, cycloheptenyl, cyclooctenyl, cyclodecenyl, cyclopentadienyl, cyclohexadienyl, cyclooctadienyl, and cyclodecadiene; and monocyclic unsaturated hydrocarbon groups such as bicyclo[2.2.1]heptyl, bicyclo[2.2.2]octyl, tricyclo[5.2.1.0 ^2,6 ]decyl, tricyclo[3.3.1.1 ^3,7 ]decyl, and tetracyclo[6.2.1.1 ^3,6 . 0 ^2,7 ]dodecyl group, adamantyl group and other polycyclic saturated hydrocarbon groups; and the like.
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, and an aryl group having 6 to 12 carbon atoms (particularly a phenyl group) is 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 halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms, with fluorine atoms, chlorine atoms, and bromine atoms being preferred.
On the other hand, specific examples of the alkyl group having 1 to 6 carbon atoms represented by R ⁷ to R ¹² 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.

As described above, ^Z1 and ^Z2 may be bonded to each other to form an aromatic ring, and an example of a structure in which ^Z1 and ^Z2 in the above formula (Ar-1) are bonded to each other to form an aromatic ring is a group represented by the following formula (Ar-1a). In the following formula (Ar-1a), *1 represents the bonding position with ^D3 or ^D4 in the above formula (1), and *2 represents the bonding position with ^D1 or ^D2 in the above formula (1). However, when l is 0, the bonding position with ^D3 represents the bonding position with ^SP1 , when m is 0, *2 represents the bonding position with ^D2 , and when n is 0, the bonding position with ^D4 represents the bonding position with ^SP2 .
In the above formula (Ar-1a), Q ¹ , Q ² and Y ¹ are the same as those explained in the above formula (Ar-1).

In the present invention, it is preferred that either Z1 or Z2 in the above formulae (Ar-1) to (Ar-8) represents a monovalent aliphatic hydrocarbon group having ¹ to 20 carbon atoms (particularly a tert- ^butyl group), for the reasons that liquid crystallinity is more easily exhibited, solubility is improved, and the durability of the optically anisotropic film to be formed is improved.
In addition, for the reason that the durability of the optically anisotropic film to be formed is improved, it is preferable that Z ¹ in the above formulas (Ar-1) to (Ar-8) represents a hydrogen atom and Z ² represents a monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms (particularly a tert-butyl group).

In the above formulas (Ar-3) and (Ar-4), ^A3 and ^A4 each independently represent a group selected from the group consisting of -O-, -N( ^R13 )-, -S-, and -CO-, and ^R13 represents a hydrogen atom or a substituent.
Examples of the substituent represented by one embodiment of R ¹³ 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.

In the formula (Ar-3), 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 non-metallic atom of Groups 14 to 16 represented by X include an oxygen atom, a sulfur atom, a nitrogen atom bonded to a hydrogen atom or a substituent [═N—R ^N1 , R ^N1 represents a hydrogen atom or a substituent], and a carbon atom bonded to a hydrogen atom or a substituent [═C(R ^C1 ) ₂ , R ^C1 represents a hydrogen atom or a substituent].
Examples of the substituent include the substituents described in the above-mentioned substituent group A. Among these, preferred examples include an alkyl group, an alkoxy group, an alkyl-substituted alkoxy group, a cyclic alkyl group, an aryl group (for example, a phenyl group, a naphthyl group, etc.), a cyano group, an amino group, a nitro group, an alkylcarbonyl group, a sulfo group, and a hydroxyl group.

In the above formula (Ar-4), ^D5 and ^D6 each independently represent a single bond, or -CO-, -O-, -S-, -C(=S)-, ^-CR1R2- , ^-CR3 = ^CR4- , ^-NR5- , or a divalent linking group formed by a combination of two or more thereof, and ^R1 to ^R5 each independently represent a hydrogen atom, a fluorine atom, or an alkyl group ^having 1 to 12 carbon atoms.
Here, examples of the divalent linking group include the same groups as those explained for D ¹ , D ² , D ³ and D ⁴ in the above formula (1).

In the above formula (Ar-4), ^SP3 and ^SP4 each independently represent a single bond or a divalent aliphatic hydrocarbon group having 1 to 20 carbon atoms. However, one or more of the _{-CH2- groups} constituting the aliphatic hydrocarbon group may be substituted with -O-, -S-, -NH-, -N(Q)- or -CO-. Q represents a substituent. Examples of the substituent represented by Q include the substituents described in the above-mentioned substituent group A, and among these, an alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group, or a halogen atom is preferred.
Here, examples of the divalent aliphatic hydrocarbon group include the same groups as those explained in relation to SP ¹ , SP ² and SP ^G in the above formula (1).

In the formula (Ar-4), L ³ and L ⁴ each independently represent a monovalent organic group, and at least one of L ³ and L ⁴ and L ¹ and L ² in the formula (1) represents a polymerizable group.
Here, examples of the monovalent organic group include the same groups as those explained for L ¹ and L ² in the above formula (1).
Examples of the polymerizable group include the same groups as those described for L ¹ and L ² in the above formula (1).

In addition, in the above formulas (Ar-5) to (Ar-8), 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-5) to (Ar-8), 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 an aromatic hydrocarbon ring and an aromatic heterocycle.
Here, the aromatic rings in Ax and Ay may have a substituent, and Ax and Ay may be bonded to form a ring.
^Q3 represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms which may have a substituent.
Examples of Ax and Ay include those described in paragraphs [0039] to [0095] of WO 2014/010325.
Specific examples of the alkyl group having 1 to 20 carbon atoms represented by ^Q3 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.

In the present invention, it is preferable that Ar ¹ and Ar ² in the above formula (1) represent any aromatic ring selected from the group consisting of groups represented by the above formulas (Ar-1) to (Ar-4), because this improves the durability of the optically anisotropic film to be formed.

Examples of the specific polymerizable liquid crystal compound represented by formula (1) include compounds represented by formulas (I) to (XII) below. Specifically, examples include compounds having the groups shown in Tables 1 to 8 below as D ¹ , G ¹ , D ² and K in formulas (I) to (VI), and compounds having the groups shown in Tables 9 below as D ¹ , G ¹ , G ¹ , D ² and K in formulas (VII) to (XII).
In the following Tables 1 to 8, the "*" shown in groups such as ^D1 indicates the bonding position.
In the following description, a compound represented by the following formula (I) and having a group shown in 1-1 in Table 1 below will be referred to as "compound (I-1-1)," and compounds having other structural formulas and groups will be referred to in the same manner. For example, a compound represented by the following formula (II) and having a group shown in 2-3 in Table 2 below can be referred to as "compound (II-2-3)."
In addition, in compound (I-1-1) and the like, 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 represents a mixture of positional isomers in which the position of the methyl group differs.

<Corresponding Compound T>
In the present invention, as described above, the HSP distance between the SPL terminal of the specific polymerizable liquid crystal compound and the alignment aid described below is 4 to 20.
Here, when the liquid crystal composition of the present invention contains two or more specific polymerizable liquid crystal compounds, the HSP distance between the SPL end of any one of the specific polymerizable compounds and the alignment aid described later may be 4 to 20.
Furthermore, the corresponding compound T used in calculating the HSP distance with the alignment aid described later is a compound represented by the following formulas (T1) and (T2), which correspond to the partial structure represented by L ¹ -SP ¹ - and the partial structure represented by L ² -SP ² - in the above formula (1) in the specific polymerizable liquid crystal compound described above.

Here, SP ¹ and L ¹ in the formula (T1) and SP ² and L ² in the formula (T2) have the same meanings as those explained in the formula (1).
Therefore, for example, when the specific polymerizable liquid crystal compound represented by the above formula (1) is a liquid crystal compound represented by the following formula L-1, the corresponding compound T used in calculating the HSP distance with the alignment aid described later is a compound represented by the following formula T-L1.

[Orientation Aid]
The alignment aid contained in the liquid crystal composition of the present invention has a boiling point of more than 250°C and not more than 350°C.
Here, the boiling point of the alignment aid refers to the boiling point at 1 atmosphere.
The boiling point of the alignment aid is preferably 260 to 320°C, and more preferably 270 to 310°C.

In the present invention, the alignment aid (hereinafter also referred to as "specific alignment aid") having a boiling point of greater than 250°C and less than or equal to 350°C is not particularly limited as long as it is a compound that has an HSP distance of 4 to 20 with the corresponding compound T described above, but is preferably a non-liquid crystal compound.

Furthermore, in the present invention, the molecular weight of the specific alignment aid is preferably 500 or less, more preferably 400 or less, and even more preferably 350 or less, because this improves both the alignment and durability of the optically anisotropic film that is formed. There is no particular lower limit for the molecular weight of the specific alignment aid, but it is preferably 100 or more, more preferably 150 or more, and even more preferably 200 or more.

In the present invention, the specific alignment aid is preferably a compound represented by the following formula (2-1), because this improves the alignment of the optically anisotropic film to be formed.

In the above formula (2-1), ^Q4 represents N or CH.
Furthermore, ^Q5 represents -S-, -O-, or -N( ^R6 )-, where ^R6 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
Specific examples of the alkyl group having 1 to 6 carbon atoms represented by one embodiment of R ⁶ 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.

In the above formula (2-1), ^Y2 represents a monovalent chain hydrocarbon group of 1 to 12 carbon atoms which may have a substituent, a monovalent heterocyclic group of 3 to 12 carbon atoms which may have a substituent, or a monovalent alicyclic hydrocarbon group of 3 to 20 carbon atoms which may have a substituent, provided that one or more of the _-CH2- groups constituting the chain hydrocarbon group and the alicyclic hydrocarbon group may be substituted with -O-, -S-, or -NH-.
Examples of the monovalent chain hydrocarbon group having 1 to 12 carbon atoms represented by one embodiment of ^Y2 include alkyl groups having 1 to 6 carbon atoms.
Examples of the monovalent heterocyclic group having 3 to 12 carbon atoms represented by one embodiment of ^Y2 include the monovalent aromatic heterocyclic groups having 3 to 12 carbon atoms (e.g., thienyl group) described for ^Y1 in the above formulae (Ar-1) and (Ar-2) as well as groups obtained by removing one hydrogen atom from a piperidine ring that does not exhibit aromaticity.
Examples of the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms represented by one embodiment of ^Y2 include, in addition to the monovalent alicyclic hydrocarbon groups having 6 to 20 carbon atoms explained for ^Y1 in the above formulae (Ar-1) and (Ar-2) (e.g., cyclohexyl group), a cyclopropyl group, a cyclobutyl group, etc.
Furthermore, examples of the chain hydrocarbon group and alicyclic hydrocarbon group in which one or more -CH ₂ - groups are substituted with -O-, -S-, or -NH- include alkylthio groups, specifically methylthio groups, ethylthio groups, etc.
In addition, examples of the substituent that ^Y2 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.

In the above formula (2-1), Z ⁴ , Z ⁵ , Z ⁶ and Z ⁷ each independently represent 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 , R ⁷ to R ¹² each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and Z ⁵ and Z ⁶ may be bonded to each other to form an aromatic ring.
Examples of Z ⁴ , Z ⁵ , Z ⁶ and Z ⁷ include the same as those explained for Z ¹ to Z ³ in the above formulae (Ar-1) to (Ar-8).

In the present invention, the specific alignment aid is preferably a compound represented by the following formula (2-2), because this improves the alignment of the optically anisotropic film to be formed.

In the above formula (2-2), D ⁷ and D ⁸ each independently represent a single bond, or —CO—, —O—, —S—, —C(═S)—, —CR ¹ R ² —, —CR ³ ═CR ⁴ —, —NR ⁵ —, or a divalent linking group formed by a combination of two or more of these, and R ¹ to R ⁵ each independently represent a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 12 carbon atoms.
D ⁷ and D ⁸ include the same groups as those described for D ¹ to D ⁴ in the above formula (1), and among them, any one of a single bond, —CO—, —O—, and —CO—O— is preferred.

In the above formula (2-2), ^P1 represents a hydrogen atom or a monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, provided that one or more of the -CH2- _groups constituting the aliphatic hydrocarbon group may be substituted with -O-, -S-, -NH-, -N(Q)- or -CO-. Q represents a substituent.
The monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms represented by one embodiment of ^P1 is preferably an alkyl group having 1 to 15 carbon atoms, more preferably an alkyl group having 1 to 8 carbon atoms, more preferably 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-dimethylbutyl group, and particularly preferably a methyl group, an ethyl group, or a tert-butyl group.
Furthermore, examples of the substituent represented by Q include the substituents described in the above-mentioned substituent group A, and among these, an alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group, or a halogen atom is preferred.

In the above formula (2-2), ^P2 represents a monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, provided that one or more of the -CH2- _groups constituting the aliphatic hydrocarbon group may be substituted with -O-, -S-, -NH-, -N(Q)- or -CO-. Q represents a substituent.
Examples of the monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms represented by one embodiment of ^P2 include the same monovalent aliphatic hydrocarbon groups having 1 to 20 carbon atoms represented by one embodiment of ^P1 .
Furthermore, examples of the monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms represented by one embodiment of ^P2 include aryl groups such as a phenyl group, a 2,6-diethylphenyl group, and a naphthyl group.
Furthermore, examples of the substituent represented by Q include the substituents described in the above-mentioned substituent group A, and among these, an alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group, or a halogen atom is preferred.

Among the specific alignment aids, examples of the compound represented by the above formula (2-1) include 2-methylthiobenzothiazole represented by the following formula (2-1-1), and compounds represented by the following formulas (2-1-2) to (2-1-12).
Furthermore, among the specific alignment aids, examples of the compound represented by the above formula (2-2) include diethyl terephthalate represented by the following formula (2-2-1), phenyl benzoate represented by the following formula (2-2-2), 4-ethylbenzoic acid represented by the following formula (2-2-3), 4-butylbenzoic acid represented by the following formula (2-2-4), and compounds represented by the following formulas (2-2-5) to (2-2-8).

In the liquid crystal composition of the present invention, the content of the specific alignment aid is preferably 0.01 to 30% by mass, more preferably 1 to 20% by mass, based on the total mass of the solid content of the liquid crystal composition.
The content of the specific alignment aid is preferably 0.01 to 30 parts by mass, and more preferably 1 to 20 parts by mass, relative to a total of 100 parts by mass of the specific polymerizable liquid crystal compound described above and the other polymerizable compounds described below (hereinafter, these are also collectively abbreviated as "total polymerizable compounds").

[Other polymerizable compounds]
From the viewpoint of alignment temperature and solubility, the liquid crystal composition of the present invention preferably contains, in addition to the specific polymerizable liquid crystal compound described above, another polymerizable compound having one or more polymerizable groups.
Here, the polymerizable group possessed by the other polymerizable compound is not particularly limited, and examples thereof include those similar to those described for ^L1 and ^L2 in the above formula (1), and among these, an acryloyloxy group or a methacryloyloxy group is preferred.
The other polymerizable compound may be a liquid crystal compound.

The other polymerizable compound is preferably another polymerizable compound having 2 to 4 polymerizable groups, and more preferably another polymerizable compound having 2 polymerizable groups, because this further improves the durability of the optically anisotropic film that is formed.

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 thereof are described in paragraphs [0046] to [0055] of the same publication.
Further, other polymerizable compounds include compounds represented by the general formula (1) described in JP-A-2010-084032 (particularly, compounds described in paragraphs [0067] to [0073]), compounds represented by the general formula (II) described in JP-A-2016-053709 (particularly, compounds described in paragraphs [0036] to [0043]), and compounds represented by the general formula (1) described in JP-A-2016-081035 (particularly, compounds described in paragraphs [0043] to [0055]), and compounds described in paragraphs [0025] to [0056] of WO 2021/060427.

[Polymerization initiator]
The liquid crystal composition of the present invention preferably contains a polymerization initiator.
The polymerization initiator used is preferably a photopolymerization initiator that can initiate a polymerization reaction by irradiation with ultraviolet light.
Examples of photopolymerization initiators include α-carbonyl compounds, acyloin ethers, α-hydrocarbon-substituted aromatic acyloin compounds, polynuclear quinone compounds, combinations of triarylimidazole dimers and p-aminophenyl ketones, acridine and phenazine compounds, oxadiazole compounds, acylphosphine oxide compounds, etc. In the present invention, the polymerization initiator is also preferably an oxime-type polymerization initiator, and specific examples thereof include the initiators described in paragraphs [0049] to [0052] of WO 2017/170443.

〔solvent〕
The liquid crystal composition of the present invention preferably contains a solvent from the viewpoint of workability in forming an optically anisotropic film.
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.

[Leveling Agent]
The liquid crystal composition of the present invention preferably contains a leveling agent from the viewpoint of maintaining a smooth surface of the cured product of the present invention, which will be described later, and facilitating alignment control.
Such a leveling agent is preferably a fluorine-based leveling agent or a silicon-based leveling agent because of the high leveling effect relative to the amount added.
Specific examples of the leveling agent include compounds described in paragraphs [0079] to [0102] of JP-A No. 2007-069471, compounds represented by general formula (I) described in JP-A No. 2013-047204 (particularly compounds described in paragraphs [0020] to [0032]), and compounds represented by general formula (I) described in JP-A No. 2012-211306 (particularly compounds described in paragraphs [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.

[Alignment Control Agent]
The liquid crystal composition of the present invention 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 specific alignment states more uniformly and with more precise control.

As the alignment control agent that promotes homogeneous alignment, for example, a low molecular weight alignment control agent or a high molecular weight alignment control agent can be used.
For low molecular weight orientation control agents, reference can be made to, 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 orientation control agents, reference can be made to, for example, paragraphs [0021] to [0057] of JP-A No. 2004-198511 and paragraphs [0121] to [0167] of JP-A No. 2006-106662, the contents of which are incorporated herein by reference.

Alignment control agents that form or promote homeotropic alignment include, for example, boronic acid compounds and onium salt compounds. Specific examples include the compounds described in JP 2008-225281 A, paragraphs [0023] to [0032], JP 2012-208397 A, paragraphs [0052] to [0058], JP 2008-026730 A, paragraphs [0024] to [0055], and JP 2016-193869 A, paragraphs [0043] to [0055], the contents of which are incorporated herein by reference.

On the other hand, cholesteric alignment can be achieved by adding a chiral agent to the polymerizable liquid crystal composition of the present invention, and the direction of rotation of the cholesteric alignment can be controlled by the direction of the chirality.
The pitch of the cholesteric alignment can be controlled depending on the alignment control force of the chiral agent.

When an alignment control agent is included, its content is preferably 0.01 to 10 mass% of the total solids in the composition, and more preferably 0.05 to 5 mass%. A content within this range achieves the desired alignment state while eliminating precipitation, phase separation, alignment defects, etc., and allows for the production of a uniform, highly transparent cured product.

[Other ingredients]
The liquid crystal composition of the present invention may contain components other than the above-mentioned components, such as a surfactant, a tilt angle controlling agent, a plasticizer, and a crosslinking agent.

[Optical anisotropic film]
The optically anisotropic film of the present invention is an optically anisotropic film obtained by fixing the alignment state of the above-mentioned liquid crystal composition of the present invention.
As a method for forming an optically anisotropic film, for example, a method in which the liquid crystal composition of the present invention is used to form a desired alignment state, and then the alignment state is fixed by polymerization, can be mentioned.
Here, the polymerization conditions are not particularly limited, but in polymerization by light irradiation, it is preferable to use ultraviolet light. The irradiation dose is preferably 10 mJ/cm ² to 50 J/cm ² , more preferably 20 mJ/cm ² to 5 J/cm ² , even more preferably 30 mJ/cm ² to 3 J/cm ² , and particularly preferably 50 to 1000 mJ/cm ^2. In addition, to promote the polymerization reaction, the polymerization may be carried out under heating conditions.
In the present invention, the optically anisotropic film can be formed on any support of the optical film of the present invention, which will be described later, or on a polarizer of the polarizing plate of the present invention, which will be described later.

In the optically anisotropic film of the present invention, the content of the above-mentioned specific alignment aid is preferably 10% by mass or less, more preferably 8% by mass or less, and even more preferably 6% by mass or less, relative to the mass of the optically anisotropic film, in order to achieve better durability. There is no particular lower limit for the content of the specific alignment aid, and it may be 0% by mass or 1% by mass or more.

In the present invention, it is preferable that the optically anisotropic film is a film obtained by orienting the above-mentioned liquid crystal composition of the present invention into a smectic phase and then polymerizing it (fixing the orientation) because this improves the contrast ratio in image display devices, particularly liquid crystal display devices.
This is thought to be because the smectic phase has a higher degree of order than the nematic phase, and scattering due to the orientation disorder of the optically anisotropic film is suppressed. Whether an optically anisotropic film exhibits a smectic phase can be determined by determining whether it has a periodic structure using X-ray diffraction. For example, the presence or absence of a periodic structure can be confirmed by analyzing the diffraction pattern using a thin film X-ray diffractometer ATXG (manufactured by Rigaku Corporation).

The optically anisotropic film of the present invention is preferably a positive A plate or a positive C plate, and more preferably a positive A plate.

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

When the optically anisotropic film of the present invention 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 140 nm.
Here, a "λ/4 plate" is a plate having a λ/4 function, specifically, a plate having the function of converting linearly polarized light of a specific wavelength into circularly polarized light (or circularly polarized light into linearly polarized light).

[Optical film]
The optical film of the present invention is an optical film having the optically anisotropic film of the present invention.
1 to 3 are schematic cross-sectional views each showing an example of the optical film of the present invention.
1 to 3 are schematic diagrams, and the thickness and positional relationships of the layers do not necessarily correspond to the actual ones. The support, alignment film, and hard coat layer shown in FIGS. 1 to 3 are all optional components.
The optical film 10 shown in FIGS. 1 to 3 has a support 16, an alignment film 14, and an optically anisotropic film 12 in this order.
Furthermore, the optical film 10 may have a hard coat layer 18 on the side of the support 16 opposite to the side on which the alignment film 14 is provided, as shown in FIG. 2, or may have a hard coat layer 18 on the side of the optically anisotropic film 12 opposite to the side on which the alignment film 14 is provided, as shown in FIG. 3.
Various members used in the optical film of the present invention will be described in detail below.

[Optical anisotropic film]
The optically anisotropic film included in the optical film of the present invention is the optically anisotropic film of the present invention described above.
In the optical film of the present invention, the thickness of the optically anisotropic film is not particularly limited, but is preferably 0.1 to 10 μm, more preferably 0.5 to 5 μm.

[Support]
As described above, the optical film of the present invention may have a support as a substrate for forming an optically anisotropic film.
Such a support is preferably transparent, and specifically, preferably has a light transmittance of 80% or more.

Examples of such supports include glass substrates and polymer films, and examples of materials for polymer films include cellulose-based polymers; acrylic polymers having acrylic acid ester polymers such as polymethyl methacrylate and lactone ring-containing polymers; thermoplastic norbornene-based polymers; polycarbonate-based polymers; polyester-based polymers such as polyethylene terephthalate and polyethylene naphthalate; styrene-based polymers such as polystyrene and acrylonitrile-styrene copolymers (AS resins); polyolefin-based polymers such as polyethylene, polypropylene, and ethylene-propylene copolymers; vinyl chloride-based polymers; amide-based polymers such as nylon and aromatic polyamides; imide-based polymers; sulfone-based polymers; polyethersulfone-based polymers; polyetheretherketone-based polymers; polyphenylene sulfide-based polymers; vinylidene chloride-based polymers; vinyl alcohol-based polymers; vinyl butyral-based polymers; arylate-based polymers; polyoxymethylene-based polymers; epoxy-based polymers; or polymers containing mixtures of these polymers.
In addition, a polarizer described later may also serve as such a support.

In the present invention, there are no particular limitations on the thickness of the support, but it is preferably 5 to 60 μm, and more preferably 5 to 30 μm.

[Alignment film]
When the optical film of the present invention has any of the above-mentioned supports, it is preferable that an alignment layer be provided between the support and the optically anisotropic film. The support may also serve as the alignment layer.

Alignment films are generally made primarily of polymers, and polymer materials for alignment films are described in numerous publications and are commercially available.
The polymer material used in the present invention is preferably polyvinyl alcohol or polyimide, or a derivative thereof, and particularly preferably modified or unmodified polyvinyl alcohol.
Examples of the alignment film that can be used in the present invention include the alignment film described in WO 01/88574, page 43, line 24 to page 49, line 8; the modified polyvinyl alcohol described in paragraphs [0071] to [0095] of Japanese Patent No. 3907735; and the liquid crystal alignment film formed from the liquid crystal aligning agent described in JP 2012-155308 A.

In the present invention, it is also preferable to use a photo-alignment film as the alignment film, since the surface of the alignment film can be prevented from being deteriorated by not coming into contact with the surface during the formation of the alignment film.
The photo-alignment film is not particularly limited, but examples thereof include polymer materials such as polyamide compounds and polyimide compounds described in paragraphs [0024] to [0043] of International Publication No. 2005/096041; liquid crystal alignment films formed from liquid crystal aligning agents having photo-alignable groups described in Japanese Patent Application Laid-Open No. 2012-155308; and products such as LPP-JP265CP (trade name) manufactured by Rolic Technologies.

In addition, in the present invention, the thickness of the alignment film is not particularly limited, but from the viewpoint of reducing surface irregularities that may exist on the support and forming an optically anisotropic film with a uniform film thickness, it is preferably 0.01 to 10 μm, more preferably 0.01 to 1 μm, and even more preferably 0.01 to 0.5 μm.

[Hard Coat Layer]
The optical film of the present invention preferably has a hard coat layer to impart physical strength to the film. Specifically, the hard coat layer may be provided on the side of the support opposite to the side on which the alignment film is provided (see FIG. 2), or on the side of the optically anisotropic film opposite to the side on which the alignment film is provided (see FIG. 3).
As the hard coat layer, those described in paragraphs [0190] to [0196] of JP-A No. 2009-98658 can be used.

[Other optically anisotropic films]
The optical film of the present invention may have other optically anisotropic films in addition to the optically anisotropic film of the present invention.
That is, the optical film of the present invention may have a laminate structure of the optically anisotropic film of the present invention and another optically anisotropic film.
Such other optically anisotropic films are not particularly limited as long as they are optically anisotropic films obtained using the above-mentioned other polymerizable compounds (particularly, liquid crystal compounds) without blending the polymerizable liquid crystal compound represented by the above formula (1).
Generally, liquid crystal compounds can be classified into rod-shaped and discotic types based on their shape. Each type can further be divided into low-molecular-weight and high-molecular-weight types. High-molecular-weight compounds generally refer to those with a degree of polymerization of 100 or more (see "Polymer Physics: Phase Transition Dynamics," by Masao Doi, p. 2, Iwanami Shoten, 1992). While any liquid crystal compound can be used in the present invention, rod-shaped or discotic liquid crystal compounds (discotic liquid crystal compounds) are preferred. Two or more rod-shaped liquid crystal compounds, two or more discotic liquid crystal compounds, or a mixture of rod-shaped and discotic liquid crystal compounds may also be used. For fixation of the liquid crystal compound, it is more preferable to form the liquid crystal using a rod-shaped or discotic liquid crystal compound having a polymerizable group, and it is even more preferable for the liquid crystal compound to have two or more polymerizable groups per molecule. In the case of a mixture of two or more liquid crystal compounds, it is preferable that at least one liquid crystal compound has two or more polymerizable groups per molecule.
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.

[Polarizing plate]
The polarizing plate of the present invention comprises the above-described optical film of the present invention and a polarizer.
Furthermore, when the above-mentioned optically anisotropic film of the present invention is a λ/4 plate (positive A plate), the polarizing plate of the present invention can be used as a circular polarizing plate.
Furthermore, in the polarizing plate of the present invention, when the optically anisotropic film of the present invention 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 means the direction in the plane of the λ/4 plate in which the refractive index is maximum, and the "absorption axis" of the polarizer means the direction in which the absorbance is highest.

[Polarizer]
The polarizer of the polarizing plate of the present invention is not particularly limited as long as it is a member having the function of converting light into specific linearly polarized light, and conventionally known absorptive polarizers and reflective polarizers can be used.
Examples of absorption polarizers include iodine-based polarizers, dye-based polarizers using dichroic dyes, polyene-based polarizers, etc. Iodine-based polarizers and dye-based polarizers include coated polarizers and stretched polarizers, and either can be used, but polarizers produced by adsorbing iodine or a dichroic dye into polyvinyl alcohol and stretching the resulting material are preferred.
Furthermore, methods for obtaining a polarizer by stretching and dyeing a laminated film in the state of forming a polyvinyl alcohol layer on a substrate can be exemplified by Japanese Patent Nos. 5,048,120, 5,143,918, 4,691,205, 4,751,481, and 4,751,486, and these known techniques related to polarizers can also be preferably utilized.
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, or the like is used.
Among these, a polarizer containing a polyvinyl alcohol resin (a polymer containing —CH ₂ —CHOH— as a repeating unit, in particular at least one selected from the group consisting of polyvinyl alcohol and an ethylene-vinyl alcohol copolymer) is preferred because of its superior adhesion.

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.

[Adhesive layer]
The polarizing plate of the present invention may have a pressure-sensitive adhesive layer disposed between the optically anisotropic film in the optical film of the present invention and the polarizer.
The pressure-sensitive adhesive layer used for laminating the optically anisotropic film and the polarizer refers to 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 pressure-sensitive adhesives and substances that tend to creep. Pressure-sensitive adhesives that can be used in the present invention include, but are not limited to, polyvinyl alcohol-based pressure-sensitive adhesives.

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

[Liquid crystal display device]
A liquid crystal display device, which is one example of the image display device of the present invention, is a liquid crystal display device having the above-described polarizing plate of the present invention and a liquid crystal cell.
In the present invention, of the polarizing plates provided on both sides of the liquid crystal cell, it is preferable to use the polarizing plate of the present invention as the front-side polarizing plate, and it is more preferable to use the polarizing plate of the present invention 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.

<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 (Opticaly Compensated Bend) mode, an IPS (In-Plane-Switching) mode, or a TN (Twisted Nematic) mode.
In TN mode liquid crystal cells, rod-shaped liquid crystal molecules are aligned substantially horizontally when no voltage is applied, and are further aligned with a twist 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 many literature.
In a VA-mode liquid crystal cell, rod-shaped liquid crystal molecules are aligned substantially vertically when no voltage is applied. VA-mode liquid crystal cells include (1) a narrow-sense VA-mode liquid crystal cell (described in Japanese Patent Laid-Open No. 2-176625) in which rod-shaped liquid crystal molecules are aligned substantially vertically when no voltage is applied and substantially horizontally when voltage is applied, as well as (2) a VA-mode liquid crystal cell (described in SID97, Digest of Tech. Papers (Proceedings) 28 (1997) 845) in which VA-mode is multi-domain to widen the viewing angle, (3) a liquid crystal cell (n-ASM mode) in which rod-shaped liquid crystal molecules are aligned substantially vertically when no voltage is applied and are aligned in a twisted multi-domain when voltage is applied (described in Proceedings of the Japan Liquid Crystal Symposium 58-59 (1998)), and (4) a SURVIVAL-mode liquid crystal cell (presented at LCD International 98). The liquid crystal display may be of any of a PVA (Patterned Vertical Alignment) type, an optical alignment type, and a PSA (Polymer-Sustained Alignment) type. Details of these modes are described in detail in Japanese Patent Laid-Open No. 2006-215326 and Japanese Patent Laid-Open No. 2008-538819.
In an IPS mode liquid crystal cell, rod-shaped liquid crystal molecules are aligned substantially parallel to the substrates, and when an electric field parallel to the substrate surface is applied, the liquid crystal molecules respond in a planar manner. In the IPS mode, a black display occurs 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 for reducing light leakage during black display in oblique directions and improving the viewing angle using an optical compensation sheet are disclosed in, for example, JP-A-10-54982, JP-A-11-202323, JP-A-9-292522, JP-A-11-133408, JP-A-11-305217, and JP-A-10-307291.

[Organic EL display device]
An organic EL display device, which is one example of the image display device of the present invention, preferably has, from the viewing side, a polarizer, a λ/4 plate (positive A plate) made of the optically anisotropic film of the present invention, and an organic EL display panel, in this order.
The organic EL display panel is a display panel configured using organic EL elements each having an organic light-emitting layer (organic electroluminescence layer) sandwiched between electrodes (a cathode and an anode). The configuration of the organic EL display panel is not particularly limited, and any known configuration may be used.

The present invention will be explained in more detail below based on the following examples. The materials, amounts used, ratios, processing details, processing procedures, etc. shown in the following examples can be modified as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be interpreted as being limited by the following examples.

[Example 1]
[Preparation of Optically Anisotropic Film A1]
<Preparation of Support>
The components described in the following cellulose acylate dope composition were charged into a mixing tank, stirred, and further heated at 90° C. for 10 minutes.
The resulting composition was then filtered through a filter paper having an average pore size of 34 μm and a sintered metal filter having an average pore size of 10 μm to prepare a cellulose acylate dope. The solid content of the cellulose acylate dope was 23.5% by mass, the amount of the plasticizer added was the ratio relative to the cellulose acylate, and the solvent for the dope was methylene chloride/methanol/butanol = 81/18/1 (mass ratio).

----------------------------------------------------------------------------------
Cellulose acylate dope composition
Cellulose acylate (acetyl substitution degree 2.86, viscosity average degree of polymerization 310) 100 parts by mass Sugar ester compound 1 (formula (S4) below) 3.0 parts by mass Sugar ester compound 2 (formula (S5) below) 1.0 part by mass Silica particle dispersion (AEROSIL R972, manufactured by Nippon Aerosil Co., Ltd.) 0.1 part by mass Solvent (methylene chloride/methanol/butanol) 351.9 parts by mass

The cellulose acylate dope prepared above was cast using a drum film-forming machine. The dope was cast from a die onto a metal support cooled to 0°C, and the resulting web (film) was then peeled off from the drum. The drum was made of SUS (stainless steel).

The web (film) obtained by casting was peeled from the drum and then dried for 20 minutes in a tenter apparatus, in which both ends of the web were clipped with clips while the film was being transported, at 30 to 40°C. Subsequently, the web was post-dried by zone heating while being transported with rolls. The obtained web was knurled and then wound up to give cellulose acylate film 1.
The resulting cellulose acylate film 1 had a thickness of 40 μm, an in-plane retardation Re(550) of 1 nm at a wavelength of 550 nm, and a thickness direction retardation Rth(550) of 23 nm at a wavelength of 550 nm.

<Preparation of Photo-Alignment Film 1>
Coating solution E1 for forming a photo-alignment film having the following composition was continuously coated with a wire bar onto the above-mentioned cellulose acylate film 1. The support on which the coating film was formed was dried with hot air at 134°C for 75 seconds, and then the coating film was irradiated with polarized ultraviolet light (8 mJ/ ^cm2 , using an ultra-high pressure mercury lamp) to form photo-alignment film 1. The film thickness of photo-alignment film 1 was 0.5 μm.

----------------------------------------------------------------------------------
Coating liquid E1 for forming photo-alignment film
----------------------------------------------------------------------------------
Polymer PA-1 (shown below) 100.00 parts by mass Acid generator PAG-1 (shown below) 6.00 parts by mass DIPEA 0.60 parts by mass Butyl acetate 625.4 parts by mass Methyl ethyl ketone 156.3 parts by mass

Polymer PA-1 (In the following formula, the numerical value for each repeating unit represents the content (% by mass) of each repeating unit relative to all repeating units; weight average molecular weight: 45,000)

Acid generator PAG-1

DIPEA

<Preparation of Optically Anisotropic Film A1>
The following liquid crystal composition F1 was applied onto the photo-alignment film 1 using a bar coater.
Next, the coating film formed on the photo-alignment film 1 was heated to 125°C with hot air, and then cooled to 60°C.
Next, the coating film was irradiated with ultraviolet light at a wavelength of 365 nm at 80 mJ/ ^cm2 using a high-pressure mercury lamp under a nitrogen atmosphere, and then irradiated with ultraviolet light at 200 mJ/ ^cm2 while heating to 120°C, thereby fixing the orientation of the liquid crystal compound and producing an optically anisotropic film A1, which is a positive A plate.
The optically anisotropic film A1 thus produced had an in-plane retardation Re(550) of 140 nm at a wavelength of 550 nm, and a film thickness of 3 μm.

----------------------------------------------------------------------------------
Liquid crystal composition F1
----------------------------------------------------------------------------------
- 8.50 parts by mass of specific polymerizable liquid crystal compound L-1 shown below - 8.50 parts by mass of specific polymerizable liquid crystal compound L-2 shown below - 45.00 parts by mass of polymerizable liquid crystal compound L-3 shown below - 32.00 parts by mass of polymerizable liquid crystal compound L-4 shown below - 6.00 parts by mass of polymerizable compound N-1 shown below - 12.00 parts by mass of methylthiobenzothiazole (alignment aid) - 0.50 parts by mass of polymerization initiator PI-1 shown below - 0.09 parts by mass of leveling agent T-1 shown below - 233.24 parts by mass of tetrahydrofuran - 58.31 parts by mass of cyclopentanone

Specific polymerizable liquid crystal compound L-1

Specific polymerizable liquid crystal compound L-2

Polymerizable liquid crystal compound L-3

Polymerizable liquid crystal compound L-4

Polymerizable compound N-1

Polymerization initiator PI-1

Leveling agent T-1 (in the formula below, the numerical value for each repeating unit represents the content (% by mass) of each repeating unit relative to all repeating units; weight average molecular weight: 25,000)

[Examples 2 to 6 and Comparative Examples 1 to 7]
An optically anisotropic film was prepared in the same manner as in Example 1, except that instead of methylthiobenzothiazole, an alignment aid shown in Table 10 below was used and the amount added was changed to the value shown in Table 10 below.

[evaluation]
(1) Orientation The prepared optically anisotropic film was placed on a polarizing microscope, the polarizers were arranged in a crossed Nicol position, and the angle of the optically anisotropic film was adjusted to set it at the extinction position. In this state, the degree of light leakage was observed, and the orientation was evaluated according to the following criteria. The results are shown in Table 10 below.
A: No light leakage.
B: Slight light leakage is observed.
C: Large light leakage.

(2) Durability The optically anisotropic film thus prepared was kept in an environment of 100°C and 95% relative humidity for 150 hours, after which the in-plane retardation was measured using an AxoScan, and the durability was evaluated according to the following criteria. The results are shown in Table 10 below.
A: The amount of change in retardation after the test is less than 10% of the value before the test. B: The amount of change in retardation after the test is 10% or more but less than 20% of the value before the test. C: The amount of change in retardation after the test is 20% or more of the value before the test.

The results shown in Table 10 show that when the boiling point of the alignment aid added to the liquid crystal composition is 250° C. or less, the alignment of the formed optically anisotropic film is poor (Comparative Examples 2 to 4).
Furthermore, it was found that when the boiling point of the alignment aid added to the liquid crystal composition exceeds 350° C., the durability of the optically anisotropic film formed is poor (Comparative Example 7).
Furthermore, it was found that even if the boiling point of the alignment aid incorporated into the liquid crystal composition is greater than 250°C and less than 350°C, if the HSP distance between the SPL end of the specific polymerizable liquid crystal compound and the alignment aid is less than 4, the alignment of the formed optically anisotropic film is poor (Comparative Examples 5 and 6).
In contrast, it was found that when the boiling point of the alignment aid incorporated into the liquid crystal composition is greater than 250°C and less than 350°C, and the HSP distance between the SPL end of the specific polymerizable liquid crystal compound and the alignment aid is 4 to 20, the alignment and durability of the formed optically anisotropic film are both good (Examples 1 to 6).
Furthermore, by comparing Examples 1 to 4 with Example 5, it was found that when the content of the specific alignment aid is 10 mass% or less relative to the mass of the optically anisotropic film, the durability of the optically anisotropic film formed is better.
Furthermore, by comparing Examples 1 to 4 with Example 6, it was found that when the specific alignment aid is a compound represented by the above-mentioned formula (2-1) or (2-2), the alignment of the optically anisotropic film formed is better.

10 Optical film 12 Optically anisotropic film 14 Alignment film 16 Support 18 Hard coat layer

Claims (8)

The liquid crystal composition contains a polymerizable liquid crystal compound represented by the following formula (1) and an alignment aid:
The boiling point of the alignment aid is higher than 250°C and not higher than 350°C,
The liquid crystal composition has a distance of 4 to 20 between the Hansen solubility parameter of at least one of compounds represented by the following formulas (T1) and (T2), which correspond to the partial structure represented by L ¹ -SP ¹ - and the partial structure represented by L ² -SP ² - in the following formula (1) in the polymerizable liquid crystal compound, and the Hansen solubility parameter of the alignment aid.
In the formulas (1), (T1) and (T2),
D ¹ , D ² , D ³ and D ⁴ each independently represent a single bond, or -CO-, -O-, -S-, -C(═S)-, -CR ¹ R ² -, -CR ³ ═CR ⁴ -, -NR ⁵ -, or a divalent linking group formed by a combination of two or more of these, and R ¹ to R ⁵ each independently represent a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 12 carbon atoms.
^G1 represents ^AG or SP ^G.
A ¹ , A ² and A ^G each independently represent an aromatic hydrocarbon ring which may have a substituent, an aromatic heterocycle which may have a substituent, or a divalent alicyclic hydrocarbon group which may have a substituent, provided that one or more of the -CH ₂ - groups constituting the alicyclic hydrocarbon group may be substituted with -O-, -S- or -NH-.
SP ¹ , SP ² and SP ^G each independently represent a single bond or a divalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, provided that one or more of the -CH ₂ - groups constituting the aliphatic hydrocarbon group may be substituted with -O-, -S-, -NH-, -N(Q)- or -CO-. Q represents a substituent.
^L1 and ^L2 each independently represent a monovalent organic group, and at least one of ^L1 and ^L2 represents a polymerizable group, provided that when at least one of ^Ar1 and ^Ar2 is an aromatic ring represented by the following formula (Ar-4), at least one of L1 and ^L2 and ^L3 and ^L4 in the following formula (Ar- ⁴ ) represents a polymerizable group.
m represents an integer of 0 to 2, and when m is 2, each of the multiple G ^1s may be the same or different, and each of the multiple D ^1s may be the same or different.
l and n each independently represent 0 or an integer of 1 or greater, and when l is an integer of 2 or greater, multiple A ¹ 's may be the same or different, and multiple D ³ 's may be the same or different, and when n is an integer of 2 or greater, multiple D ⁴ 's may be the same or different, and multiple A ² 's may be the same or different.
p represents an integer of 1 to 3. When p is 2 or 3, multiple Ar ¹ 's may be the same or different from each other, and multiple D ² 's may be the same or different from each other, and when p is 2 or 3 and m is not 0, multiple G ¹ 's may be the same or different from each other, and multiple D ¹ 's may be the same or different from each other.
Ar ¹ and Ar ² each independently represent any aromatic ring selected from the group consisting of groups represented by the following formulae (Ar-1) to (Ar-8).
Here, in the formulas (Ar-1) to (Ar-8),
*1 represents the bonding position with D3 or ^D4 , ^and *2 represents the bonding position with ^D1 or ^D2 . However, when l is 0, the bonding position with ^D3 represents the bonding position with ^SP1 , when m is 0, *2 represents the bonding position with ^D2 , and when n is 0, the bonding position with ^D4 represents the bonding position with ^SP2 .
^Q1 represents N or CH.
^Q2 represents -S-, -O-, or -N( ^R6 )-, and ^R6 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
^Y1 represents a monovalent aromatic hydrocarbon group of 6 to 12 carbon atoms which may have a substituent, a monovalent aromatic heterocyclic group of 3 to 12 carbon atoms which may have a substituent, or a monovalent alicyclic hydrocarbon group of 6 to 20 carbon atoms which may have a substituent, provided that one or more of the -CH ₂ - groups constituting the alicyclic hydrocarbon group may be substituted with -O-, -S- or -NH-.
Z ¹ , Z ² and Z ³ each independently represent 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 , where R ⁷ to R ¹² each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and Z ¹ and Z ² may be bonded to each other to form an aromatic ring.
A ³ and A ⁴ each independently represent a group selected from the group consisting of —O—, —N(R ¹³ )—, —S—, and —CO—, and R ¹³ represents a hydrogen atom or a substituent.
X represents a nonmetallic atom of Groups 14 to 16. However, the nonmetallic atom may be bonded to a hydrogen atom or a substituent.
^D5 and ^D6 each independently represent a single bond, or -CO-, -O-, -S-, -C(=S)-, ^-CR1R2- , ^-CR3 = ^CR4- , ^-NR5- , or a divalent linking group formed by a combination of two or more thereof, and ^R1 to ^R5 each independently represent a hydrogen atom ^, a fluorine atom, or an alkyl group having 1 to 12 carbon atoms.
^SP3 and ^SP4 each independently represent a single bond or a divalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, provided that one or more of the _-CH2- groups constituting the aliphatic hydrocarbon group may be substituted with -O-, -S-, -NH-, -N(Q)- or -CO-. Q represents a substituent.
^L3 and ^L4 each independently represent a monovalent organic group, and at least one of L3 ^{and L4} and ^L1 and ^L2 in the formula (1) 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 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 an aromatic hydrocarbon ring and an aromatic heterocycle.
The aromatic rings in Ax and Ay may have a substituent, and Ax and Ay may be bonded to form a ring.
^Q3 represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms which may have a substituent. The liquid crystal composition according to claim 1, wherein the molecular weight of the alignment aid is 500 or less. 2. The liquid crystal composition according to claim 1, wherein the alignment aid is a compound represented by the following formula (2-1) or (2-2):
Here, in the formula (2-1),
^Q4 represents N or CH.
^Q5 represents -S-, -O-, or -N( ^R6 )-, and ^R6 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
^Y2 represents a monovalent chain hydrocarbon group of 1 to 12 carbon atoms which may have a substituent, a monovalent heterocyclic group of 3 to 12 carbon atoms which may have a substituent, or a monovalent alicyclic hydrocarbon group of 3 to 20 carbon atoms which may have a substituent, provided that one or more of the _{-CH2- groups} constituting the chain hydrocarbon group and the alicyclic hydrocarbon group may be substituted with -O-, -S- or -NH-.
Z ⁴ , Z ⁵ , Z ⁶ and Z ⁷ each independently represent 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 , R ⁷ to R ¹² each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and Z ⁵ and Z ⁶ may be bonded to each other to form an aromatic ring.
In addition, in the formula (2-2),
D ⁷ and D ⁸ each independently represent a single bond, or -CO-, -O-, -S-, -C(═S)-, -CR ¹ R ² -, -CR ³ ═CR ⁴ -, -NR ⁵ -, or a divalent linking group formed by a combination of two or more thereof, and R ¹ to R ⁵ each independently represent a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 12 carbon atoms.
^P1 represents a hydrogen atom or a monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, provided that one or more of the -CH ₂ - groups constituting the aliphatic hydrocarbon group may be substituted with -O-, -S-, -NH-, -N(Q)- or -CO-. Q represents a substituent.
^P2 represents a monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms, provided that one or more of the -CH ₂ - groups constituting the aliphatic hydrocarbon group may be substituted with -O-, -S-, -NH-, -N(Q)- or -CO-. Q represents a substituent. An optically anisotropic film obtained by fixing the alignment state of the liquid crystal composition according to any one of claims 1 to 3. The optically anisotropic film according to claim 4, wherein the content of the alignment aid is 10% by mass or less relative to the mass of the optically anisotropic film. An optical film having the optically anisotropic film described in claim 4. A polarizing plate comprising the optical film of claim 6 and a polarizer. An image display device comprising the optical film according to claim 6 and a display element.