JP7405576B2 - optically anisotropic film - Google Patents

Description

The present invention relates to an optically anisotropic film, an optical film, an elliptically polarizing plate, a laminate, and an organic EL display device including the same.

An elliptically polarizing plate is an optical member in which a polarizing film and a retardation film are laminated. For example, in a device that displays an image in a flat state, such as an organic EL image display device, the elliptically polarizing plate prevents light reflection at the electrodes that constitute the device. It is used to prevent A so-called λ/4 plate is generally used as a retardation film constituting this elliptically polarizing plate.

The retardation film constituting the elliptically polarizing plate is preferably one that exhibits reverse wavelength dispersion, since it easily exhibits uniform retardation performance over a wide wavelength range of visible light. As such a retardation film, a stretched film stretched in a desired orientation direction or a polymerizable liquid crystal compound exhibiting reverse wavelength dispersion is polymerized and cured while oriented horizontally with respect to the plane of the retardation film. A retardation film composed of a horizontally aligned liquid crystal cured film is known.

Japanese Patent Application Publication No. 2015-163935

However, in a conventional retardation film exhibiting reverse wavelength dispersion, the retardation value of the retardation film may change over time. The retardation value of the retardation film greatly influences the reflected hue of the elliptically polarizing plate when the retardation film is incorporated into the elliptically polarizing plate. Therefore, when such a change in retardation value occurs over time, it becomes difficult to obtain a desired reflection hue in an image display device incorporating an elliptically polarizing plate including the retardation film, and the optical properties change over time. This is one of the causes of deterioration in quality and defects in appearance quality.

The present invention relates to an optically anisotropic film that does not easily change its retardation value over time and can exhibit excellent optical properties for a long period of time when incorporated into an image display device, an optical film containing the same, and an elliptically polarized film. The purpose of the present invention is to provide a plate, a laminate, and an organic EL display device.

The present inventors have completed the present invention as a result of intensive studies to solve the above problems. That is, the present invention includes the following aspects.
[1] Formula (1):
1.002≦nyA(450)/nzA(450)≦1.010 (1)
[In formula (1), nyA (450) is the wavelength λ = 450 nm in the direction y perpendicular to the direction x (slow axis direction) showing the highest in-plane principal refractive index in the same plane. nzA (450) represents the refractive index at wavelength λ = 450 nm in the film thickness direction of the optically anisotropic film]
And formula (2):
ReA(450)/ReA(550)<1.00 (2)
[In formula (2), ReA (λ) represents the in-plane retardation value of the optically anisotropic film at the wavelength λ nm, and ReA (λ) = (nxA (λ) - nyA (λ)) x dA [ In the formula, nxA(λ) represents the refractive index at wavelength λnm in the plane of the optically anisotropic film, and nyA(λ) represents the refractive index at wavelength λnm in the same plane as nxA in the direction orthogonal to the direction of nxA. It represents the refractive index, and dA represents the thickness of the optically anisotropic film.]
An optically anisotropic film that satisfies the following requirements.
[2] Formula (3):
1.002≦nyA(550)/nzA(550)≦1.010 (3)
[In formula (3), nyA (550) is the wavelength λ = 550 nm in the direction y perpendicular to the direction x (slow axis direction) showing the highest refractive index among the in-plane principal refractive indexes in the same plane. nzA (550) represents the refractive index at wavelength λ = 550 nm in the film thickness direction of the optically anisotropic film]
The optically anisotropic film according to [1] above, which satisfies the following.
[3] The optically anisotropic film according to [1] or [2] above, which is a cured product of a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound having at least one polymerizable group.
[4] A cured product of a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound having at least one polymerizable group, in which the polymerizable liquid crystal compound is oriented in the horizontal direction with respect to the plane of the optically anisotropic film. The optically anisotropic film according to any one of [1] to [3] above, which is cured with.
[5] Formula (4):
120nm≦ReA(550)≦170nm (4)
[In formula (4), ReA (550) represents the in-plane retardation value of the optically anisotropic film at a wavelength of 550 nm]
The optically anisotropic film according to any one of [1] to [4] above, which satisfies the following.
[6] An optical film comprising the optically anisotropic film according to any one of [1] to [5] above.
[7] An elliptically polarizing plate comprising the optically anisotropic film according to any one of [1] to [5] above and a polarizing film.
[8] The elliptically polarizing plate according to [7], wherein the angle between the slow axis of the optically anisotropic film and the absorption axis of the polarizing film is 45±5°.
[9] A laminate comprising the elliptically polarizing plate according to [7] or [8] and a front plate.
[10] A laminate comprising the elliptically polarizing plate according to [7] or [8] and a touch sensor panel.
[11] An organic EL display device including the laminate according to [9] or [10].

According to the present invention, an optically anisotropic film that does not easily change its retardation value over time and can exhibit excellent optical properties for a long period of time when incorporated into an image display device, and an optical film containing the same, An elliptically polarizing plate, a laminate, and an organic EL display device can be provided.

The optically anisotropic film of the present invention satisfies formula (1).
1.002≦nyA(450)/nzA(450)≦1.010 (1)
In formula (1), nyA (450) is the wavelength λ = 450 nm in the direction y perpendicular to the direction x (slow axis direction) showing the highest refractive index among the in-plane principal refractive indexes in the same plane. nzA(450) represents the refractive index at wavelength λ=450 nm in the film thickness direction of the optically anisotropic film.
By satisfying the formula (1), it is possible to obtain an optically anisotropic film in which the retardation value is less likely to change over time and can maintain its initial optical properties over a long period of time.

The optically anisotropic film of the present invention satisfies formula (2) in addition to formula (1).
ReA(450)/ReA(550)<1.00 (2)
In formula (2), ReA(λ) represents the in-plane retardation value of the optically anisotropic film at the wavelength λnm, and ReA(λ)=(nxA(λ)−nyA(λ))×dA. In the above formula, nxA(λ) represents the refractive index at wavelength λnm in the plane of the optically anisotropic film, and nyA(λ) represents the refractive index at wavelength λnm in the same plane as nxA in the direction orthogonal to the direction of nxA. represents the refractive index of , and dA represents the thickness of the optically anisotropic film.
In addition to Equation (1), by satisfying Equation (2), which indicates so-called reverse wavelength dispersion, it is possible to exhibit uniform retardation performance over a wide wavelength range of visible light, resulting in excellent optical properties over a long period of time. This results in an optically anisotropic film that can be suitably used as a component of an image display device that maintains display characteristics. ReA(450)/ReA(550) is preferably 0.70 or more, more preferably is 0.78 or more, and is preferably 0.95 or less, more preferably 0.92 or less, even more preferably 0.90 or less, particularly preferably 0.87 or less, particularly preferably 0.85 or less. .

The in-plane retardation value can be adjusted by adjusting the thickness dA of the optically anisotropic film. Since the in-plane retardation value is determined by the above formula ReA(λ)=(nxA(λ)-nyA(λ))×dA, the desired in-plane retardation value (ReA(λ):wavelength λ( In order to obtain the in-plane retardation value (in-plane retardation value) of the optically anisotropic film in (nm), the three-dimensional refractive index and film thickness dA may be adjusted.

It is preferable that the optically anisotropic film of the present invention further satisfies formula (3).
1.002≦nyA(550)/nzA(550)≦1.010 (3)
In formula (3), nyA (550) is the wavelength λ = 550 nm in the direction y perpendicular to the direction x (slow axis direction) showing the highest refractive index among the in-plane principal refractive indexes in the same plane. nzA(550) represents the refractive index at wavelength λ=550 nm in the film thickness direction of the optically anisotropic film.
By satisfying formula (3), the effect of suppressing changes in retardation value over time tends to be further improved, and an optically anisotropic film that can exhibit its initial optical properties for a long period of time can be obtained.

Further, it is preferable that the optically anisotropic film of the present invention satisfies formula (4).
120nm≦ReA(550)≦170nm (4)
In formula (4), ReA (550) represents the in-plane retardation value of the optically anisotropic film at wavelength λ=550 nm.
When the in-plane retardation value ReA (550) of the optically anisotropic film is within the range of formula (4), the effect of improving the frontal reflection hue when the optically anisotropic film is applied to a display device (coloring (inhibiting effect) becomes noticeable. A more preferable range of the in-plane retardation value is 130 nm≦ReA(550)≦150 nm. In addition, hereinafter, the effect related to "improving the front reflection hue" in this specification means the improvement effect in the front reflection hue when the elliptically polarizing plate containing the optically anisotropic film of the present invention is applied to a display device.

The optically anisotropic film of the present invention preferably satisfies formula (5).
nxA(450)>nyA(450)>nzA(450) (5)
In formula (5), nxA (450), nyA (450) and nzA (450) have the same meanings as above.
When formula (5) is satisfied, the wavelength dispersion of the optically anisotropic film tends to be further improved [that is, the value of ReA(450)/ReA(550) becomes smaller]; When the film is applied to an image display device, better frontal reflection hue can be obtained.

Moreover, it is preferable that the optically anisotropic film of the present invention satisfies formula (6).
nxA(550)>nyA(550)>nzA(550) (6)
In formula (6), nxA (550), nyA (550) and nzA (550) have the same meanings as above.
When formula (6) is satisfied, the wavelength dispersion of the optically anisotropic film tends to be further improved, so when the optically anisotropic film is applied to an image display device, a better frontal reflection hue can be obtained. be able to. In particular, by satisfying the above formula (6) as well as formula (5), the effect of improving the front reflection hue when the optically anisotropic film is applied to an image display device can be significant.

The optically anisotropic film of the present invention may be formed as long as it satisfies the optical properties shown by formulas (1) and (2). For example, a stretched film obtained by stretching a base material formed from a transparent resin such as polyethylene terephthalate, poly(meth)acrylic acid ester, cellulose ester, cyclic olefin resin, polycarbonate, polyamide, polyimide, polyamideimide, etc. or a cured product (cured film) of a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound having at least one polymerizable group. Among these, an optically anisotropic film having retardation performance that is oriented horizontally with respect to the in-plane direction of the film is preferable, and a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound having at least one polymerizable group is preferable. More preferably, the cured product is a cured product obtained by curing the polymerizable liquid crystal compound in a state in which it is oriented horizontally with respect to the plane of the optically anisotropic film (hereinafter also referred to as "horizontally aligned liquid crystal cured film"). .

When the optically anisotropic film of the present invention is a horizontally aligned liquid crystal cured film, the optically anisotropic film has an in-plane retardation value at a short wavelength that is smaller than an in-plane retardation value at a long wavelength. It can be formed from a polymerizable liquid crystal compound exhibiting so-called reverse wavelength dispersion. Polymerizable liquid crystal compounds that exhibit such reverse wavelength dispersion usually have a T-shaped structure in which constituent molecules are arranged in the long axis direction of the main chain of the compound and in the direction crossing the long axis direction. (Hereinafter, the molecular structure part forming the long axis direction of the polymerizable liquid crystal compound is also referred to as the "mesogen part", and the molecular structure part forming the direction crossing the long axis direction is also referred to as the "core part". ). Conventionally, in a horizontally aligned liquid crystal cured film exhibiting reverse wavelength dispersion, the refractive indices nxA, nyA, and nzA in three directions in the refractive index ellipsoid formed by the orientation of the polymerizable liquid crystal compound are nxA>nyA≒nzA (positive A plate). In the above positive A plate, the directionality (orientation) of the constituent molecules arranged in the direction intersecting the long axis direction of the polymerizable liquid crystal compound having a T-shaped structure is not controlled, and the directionality (orientation) of the constituent molecules is not controlled within the plane of the cured liquid crystal film. The refractive index nyA in the direction perpendicular to the direction of nxA and the refractive index nzA in the direction perpendicular to the plane of the liquid crystal cured film are theoretically the same (nyA≈nzA).

In contrast, the present invention controls the directionality (orientation) of constituent molecules arranged in a direction intersecting the long axis direction of a polymerizable liquid crystal compound having a T-shaped structure, and The refractive index nyA in the direction perpendicular to the direction x (slow axis direction) showing a high refractive index in the same plane, and the refractive index nzA in the film thickness direction (perpendicular direction) to the plane of the optically anisotropic film. The ratio [nyA(λ)/nzA(λ)] is set within a specific range. That is, the optically anisotropic film of the present invention has the formula (1):
1.002≦nyA(450)/nzA(450)≦1.010 (1)
satisfy.
In the present invention, the principle of the effect of suppressing changes in the retardation value over time due to the optically anisotropic film satisfying formula (1) is not necessarily clear, but it is presumed as follows. When the ratio of nyA(λ) and nzA(λ) is within the above specific range, the optically anisotropic film has a mesogen part of the polymerizable liquid crystal compound in the x direction and a core part in the same plane within the film plane. The liquid crystal cured film is polymerized in a state selectively oriented in the y direction perpendicular to the x direction, and is cured. This kind of cured liquid crystal film has a certain directional stacking between the core parts of each polymerizable liquid crystal compound that makes up the cured liquid crystal film in the initial state after film formation, and has high structural stability. has. Therefore, compared to the conventional positive A plate in which the directionality of the isotropically distributed core part tends to change over time, the directionality of the constituent molecules of the polymerizable liquid crystal compound ( The optically anisotropic film of the present invention in which the orientation of the polymerizable liquid crystal compound is controlled is difficult to cause changes in the orientation state of the polymerizable liquid crystal compound, and it is possible to suppress changes over time in the retardation value caused by changes in the orientation state. It becomes possible.

The polymerizable liquid crystal compound having at least one polymerizable group for forming an optically anisotropic film is particularly limited as long as it can form a cured liquid crystal film that satisfies the above formulas (1) and (2). Instead, polymerizable liquid crystal compounds conventionally known in the field of retardation films can be used.

A polymerizable group means a group that can participate in a polymerization reaction. The polymerizable liquid crystal compound forming the optically anisotropic film of the present invention uses a photopolymerizable group that can participate in a polymerization reaction by reactive species generated from a photopolymerization initiator, such as an active radical or an acid. It is preferable to have. Examples of the photopolymerizable group include vinyl group, vinyloxy group, 1-chlorovinyl group, isopropenyl group, 4-vinylphenyl group, acryloyloxy group, methacryloyloxy group, oxiranyl group, oxetanyl group, and the like. Among these, acryloyloxy group, methacryloyloxy group, vinyloxy group, oxiranyl group and oxetanyl group are preferable, and acryloyloxy group is more preferable.

The liquid crystallinity exhibited by the polymerizable liquid crystal compound may be a thermotropic liquid crystal or a lyotropic liquid crystal, but a thermotropic liquid crystal is preferable because it allows precise film thickness control. Further, the phase ordered structure of the thermotropic liquid crystal may be either a nematic liquid crystal or a smectic liquid crystal. The polymerizable liquid crystal compounds can be used alone or in combination of two or more.

Examples of polymerizable liquid crystal compounds include polymerizable liquid crystal compounds that generally exhibit positive wavelength dispersion and polymerizable liquid crystal compounds that exhibit reverse wavelength dispersion, and the resulting optically anisotropic film has optical properties that satisfy formula (2). (that is, exhibits reverse wavelength dispersion), it is possible to use only one type of polymerizable liquid crystal compound, or it is also possible to use a mixture of two or more types of polymerizable liquid crystal compounds of both types. can. Since it is easy to improve the front reflection hue in an image display device incorporating the obtained optically anisotropic film, and the durability improvement effect of the present invention can be easily obtained, the polymerizable liquid crystal compound is oriented alone in a specific direction. It is preferable that the polymer obtained by polymerizing in this state contains a polymerizable liquid crystal compound exhibiting reverse wavelength dispersion. As the polymerizable liquid crystal compound, only one type may be used, or two or more types may be used in combination.

The polymerizable liquid crystal compound is preferably a compound having the following characteristics (A) to (D).
(A) A compound capable of forming a nematic phase or a smectic phase.
(B) The polymerizable liquid crystal compound has π electrons in the long axis direction (a).
(C) It has π electrons in a direction [intersecting direction (b)] that intersects with the major axis direction (a).
(D) A polymerizable liquid crystal compound defined by the following formula (i) where the total of π electrons present in the major axis direction (a) is N (πa) and the total molecular weight present in the major axis direction is N (Aa) π electron density in the long axis direction (a):
D(πa)=N(πa)/N(Aa) (i)
and a polymerizable liquid crystal compound defined by the following formula (ii) where the total of π electrons existing in the intersecting direction (b) is N (πb), and the total molecular weight existing in the intersecting direction (b) is N (Ab) π electron density in the crossing direction (b):
D(πb)=N(πb)/N(Ab) (ii)
is the formula (iii)
0≦[D(πa)/D(πb)]<1 (iii)
[That is, the π electron density in the cross direction (b) is larger than the π electron density in the major axis direction (a)]. Further, as described above, a polymerizable liquid crystal compound having π electrons on the long axis and in a direction crossing the long axis generally tends to have a T-shaped structure.

In the features (A) to (D) above, the major axis direction (a) and the number N of π electrons are defined as follows.
- For example, in the case of a compound having a rod-like structure, the long axis direction (a) is the long axis direction of the rod.
- The number of π electrons N (πa) existing in the major axis direction (a) does not include π electrons that disappear due to polymerization reactions.
・The number N (πa) of π electrons existing on the long axis direction (a) is the total number of π electrons on the long axis and π electrons conjugated with this, for example, the number N (πa) existing on the long axis direction (a). It includes the number of π electrons present in a ring that satisfies Huckel's rule.
- The number of π electrons N (πb) existing in the cross direction (b) does not include π electrons that disappear due to the polymerization reaction.
A polymerizable liquid crystal compound that satisfies the above has a mesogenic structure in the long axis direction. This mesogenic structure develops a liquid crystal phase (nematic phase, smectic phase).

Forming a nematic phase or a smectic phase by coating a polymerizable liquid crystal compound that satisfies the above (A) to (D) on a film (layer) that forms a cured liquid crystal film and heating it above the phase transition temperature. is possible. In the nematic phase or smectic phase formed by aligning this polymerizable liquid crystal compound, the long axes of the polymerizable liquid crystal compound are usually oriented parallel to each other, and the long axes are aligned in the nematic phase or smectic phase. is the orientation direction. When such a polymerizable liquid crystal compound is formed into a film and polymerized in a nematic phase or smectic phase, a polymer film consisting of polymers oriented in the long axis direction (a) can be formed. . This polymer film absorbs ultraviolet light by π electrons in the major axis direction (a) and π electrons in the cross direction (b). Here, the absorption maximum wavelength of ultraviolet rays absorbed by π electrons in the cross direction (b) is assumed to be λbmax. λbmax is typically 300 nm to 400 nm. The density of π electrons satisfies the above formula (iii), and since the π electron density in the cross direction (b) is larger than the π electron density in the major axis direction (a), there is a vibration plane in the cross direction (b). The polymer film has a larger absorption of linearly polarized ultraviolet rays (wavelength: λbmax) having a wavelength of λbmax than that of linearly polarized ultraviolet rays (wavelength: λbmax) having a vibration plane in the major axis direction (a). The ratio (ratio of absorbance in the cross direction (b) of linearly polarized ultraviolet light/absorbance in the major axis direction (a)) is, for example, more than 1.0, preferably 1.2 or more, and usually 30 or less, for example, 10 or less. It is.

Generally, the polymerizable liquid crystal compound having the above-mentioned characteristics is one in which the birefringence of the polymer exhibits reverse wavelength dispersion when polymerized in a unidirectionally oriented state. Specifically, for example, a compound represented by the following formula (X) may be mentioned.

In formula (X), Ar represents a divalent group having an aromatic group which may have a substituent. The aromatic group here refers to a ring structure in which the number of π electrons is [4n+2] according to Huckel's rule, and is exemplified by (Ar-1) to (Ar-23) described below. It may have two or more such Ar groups via a divalent linking group. Here n represents an integer. In the case where a ring structure is formed containing heteroatoms such as -N= and -S-, it also satisfies Huckel's rule including non-covalently bonded electron pairs on these heteroatoms and has aromaticity. Preferably, the aromatic group contains at least one of a nitrogen atom, an oxygen atom, and a sulfur atom. The number of aromatic groups contained in the divalent group Ar may be one, or two or more. When there is one aromatic group, the divalent group Ar may be a divalent aromatic group which may have a substituent. When the divalent group Ar contains two or more aromatic groups, the two or more aromatic groups are bonded to each other through a single bond or a divalent bonding group such as -CO-O- or -O-. You can leave it there.
G ¹ and G ² each independently represent a divalent aromatic group or a divalent alicyclic hydrocarbon group. Here, the hydrogen atom contained in the divalent aromatic group or divalent alicyclic hydrocarbon group is a halogen atom, an alkyl group having 1 to 4 carbon atoms, a fluoroalkyl group having 1 to 4 carbon atoms, or a fluoroalkyl group having 1 to 4 carbon atoms. It may be substituted with 1 to 4 alkoxy groups, cyano groups, or nitro groups, and the carbon atoms constituting the divalent aromatic group or divalent alicyclic hydrocarbon group are oxygen atoms, sulfur atoms. Alternatively, it may be substituted with a nitrogen atom.
L ¹ , L ² , B ¹ and B ² are each independently a single bond or a divalent linking group.
k and l each independently represent an integer from 0 to 3, and satisfy the relationship 1≦k+l. Here, when 2≦k+l, B ¹ and B ² and G ¹ and G ² may be the same or different from each other.
E ¹ and E ² each independently represent an alkanediyl group having 1 to 17 carbon atoms, with an alkanediyl group having 4 to 12 carbon atoms being more preferred. Furthermore, the hydrogen atom contained in the alkanediyl group may be substituted with a halogen atom, and the -CH ₂ - contained in the alkanediyl group is replaced by -O-, -S-, -SiH ₂ -, -C (=O)- may be substituted.
P ¹ and P ² each independently represent a polymerizable group or a hydrogen atom, and at least one of them is a polymerizable group.

G ¹ and G ² are each independently preferably a 1,4-phenylenediyl group optionally substituted with at least one substituent selected from the group consisting of a halogen atom and an alkyl group having 1 to 4 carbon atoms. , a 1,4-cyclohexanediyl group optionally substituted with at least one substituent selected from the group consisting of a halogen atom and an alkyl group having 1 to 4 carbon atoms, and more preferably a 1,4-cyclohexanediyl group substituted with a methyl group. ,4-phenylenediyl group, unsubstituted 1,4-phenylenediyl group, or unsubstituted 1,4-trans-cyclohexanediyl group, particularly preferably unsubstituted 1,4-phenylenediyl group or unsubstituted It is a substituted 1,4-trans-cyclohexanediyl group.
Furthermore, at least one of the plurality of G ¹ and G ² is preferably a divalent alicyclic hydrocarbon group, and at least one of G ¹ and G ² bonded to L ¹ or L ² More preferably, one is a divalent alicyclic hydrocarbon group.

L ¹ and L ² are each independently preferably a single bond, an alkylene group having 1 to 4 carbon atoms, -O-, -S-, -R ^a1 OR ^a2 -, -R ^a3 COOR ^a4 -, -R ^a5 OCOR ^a6 -, -R ^a7 OC=OOR ^a8 -, -N=N-, -CR ^c =CR ^d -, or -C≡C-. Here, R ^a1 to R ^a8 each independently represent a single bond or an alkylene group having 1 to 4 carbon atoms, and R ^c and R ^d represent an alkyl group having 1 to 4 carbon atoms or a hydrogen atom. L ¹ and L ² are each independently more preferably a single bond, -OR ^a2-1 -, -CH ₂ -, -CH ₂ CH ₂ -, -COOR ^a4-1 -, or -OCOR ^a6-1 - be. Here, R ^a2-1 , R ^a4-1 , and R ^a6-1 each independently represent a single bond, -CH ₂ -, or -CH ₂ CH ₂ -. L ¹ and L ² are each independently more preferably a single bond, -O-, -CH ₂ CH ₂ -, -COO-, -COOCH ₂ CH ₂ -, or -OCO-.

B ¹ and B ² are each independently preferably a single bond, an alkylene group having 1 to 4 carbon atoms, -O-, -S-, -R ^a9 OR ^a10 -, -R ^a11 COOR ^a12 -, -R ^a13 OCOR ^a14 - or -R ^a15 OC=OOR ^a16 -. Here, R ^a9 to R ^a16 each independently represent a single bond or an alkylene group having 1 to 4 carbon atoms. B ¹ and B ² are each independently more preferably a single bond, -OR ^a10-1 -, -CH ₂ -, -CH ₂ CH ₂ -, -COOR ^a12-1 -, or -OCOR ^a14-1 - be. Here, R ^a10-1 , R ^a12-1 , and R ^a14-1 each independently represent a single bond, -CH ₂ -, or -CH ₂ CH ₂ -. B ¹ and B ² are each independently, more preferably, a single bond, -O-, -CH ₂ CH ₂ -, -COO-, -COOCH ₂ CH ₂ -, -OCO-, or -OCOCH ₂ CH ₂ - be.

From the viewpoint of expressing reverse wavelength dispersion, k and l are preferably in the range of 2≦k+l≦6, preferably k+l=4, and more preferably k=2 and l=2. It is preferable that k=2 and l=2 because a symmetrical structure is obtained.

Examples of the polymerizable group represented by P ¹ or P ² include epoxy group, vinyl group, vinyloxy group, 1-chlorovinyl group, isopropenyl group, 4-vinylphenyl group, acryloyloxy group, methacryloyloxy group, and oxiranyl group. , and oxetanyl group. Among these, acryloyloxy group, methacryloyloxy group, vinyl group and vinyloxy group are preferable, and acryloyloxy group and methacryloyloxy group are more preferable.

It is preferable that Ar has at least one selected from an aromatic hydrocarbon ring which may have a substituent, an aromatic heterocycle which may have a substituent, and an electron-withdrawing group. Examples of the aromatic hydrocarbon ring include a benzene ring, a naphthalene ring, an anthracene ring, and the like, with benzene rings and naphthalene rings being preferred. The aromatic heterocycles include a furan ring, a benzofuran ring, a pyrrole ring, an indole ring, a thiophene ring, a benzothiophene ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, a triazole ring, a triazine ring, a pyrroline ring, an imidazole ring, and a pyrazole ring. , thiazole ring, benzothiazole ring, thienothiazole ring, oxazole ring, benzoxazole ring, and phenanthroline ring. Among these, it is preferable to have a thiazole ring, benzothiazole ring, or benzofuran ring, and more preferably to have a benzothiazole group. Further, when Ar includes a nitrogen atom, it is preferable that the nitrogen atom has π electrons.

In formula (X), the total number N _π of π electrons contained in the divalent aromatic group represented by Ar is preferably 8 or more, more preferably 10 or more, still more preferably 14 or more, and especially Preferably it is 16 or more. Further, it is preferably 32 or less, more preferably 30 or less, even more preferably 26 or less, particularly preferably 24 or less.

Examples of the aromatic group represented by Ar include the following groups.

In formulas (Ar-1) to (Ar-23), the mark * represents a connecting part, and Z ⁰ , Z ¹ and Z ² each independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 to 12 carbon atoms. group, cyano group, nitro group, alkylsulfinyl group having 1 to 12 carbon atoms, alkylsulfonyl group having 1 to 12 carbon atoms, carboxyl group, fluoroalkyl group having 1 to 12 carbon atoms, alkoxy group having 1 to 12 carbon atoms, Alkylthio group having 1 to 12 carbon atoms, N-alkylamino group having 1 to 12 carbon atoms, N,N-dialkylamino group having 2 to 12 carbon atoms, N-alkylsulfamoyl group having 1 to 12 carbon atoms, or carbon Represents an N,N-dialkylsulfamoyl group having numbers 2 to 12. Moreover, Z ⁰ , Z ¹ and Z ² may contain a polymerizable group.

Q ¹ and Q ² each independently represent -CR ^2' R ^3' -, -S-, -NH-, -NR ^2' -, -CO- or -O-, and R ^2' and R ^{3 '} each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

J ¹ and J ² each independently represent a carbon atom or a nitrogen atom.

Y ¹ , Y ² and Y ³ each independently represent an optionally substituted aromatic hydrocarbon group or aromatic heterocyclic group.

W ¹ and W ² each independently represent a hydrogen atom, a cyano group, a methyl group, or a halogen atom, and m represents an integer of 0 to 6.

Examples of the aromatic hydrocarbon group for Y ¹ , Y ² and Y ³ include aromatic hydrocarbon groups having 6 to 20 carbon atoms such as phenyl group, naphthyl group, anthryl group, phenanthryl group, and biphenyl group. , naphthyl group is preferred, and phenyl group is more preferred. Examples of the aromatic heterocyclic group include a group having 4 to 20 carbon atoms and containing at least one heteroatom such as a nitrogen atom, an oxygen atom, or a sulfur atom, such as a furyl group, a pyrrolyl group, a thienyl group, a pyridinyl group, a thiazolyl group, and a benzothiazolyl group. Examples include aromatic heterocyclic groups, and furyl, thienyl, pyridinyl, thiazolyl, and benzothiazolyl groups are preferred.

Y ¹ , Y ² and Y ³ may each independently be an optionally substituted polycyclic aromatic hydrocarbon group or a polycyclic aromatic heterocyclic group. The polycyclic aromatic hydrocarbon group refers to a fused polycyclic aromatic hydrocarbon group or a group derived from an aromatic ring assembly. The polycyclic aromatic heterocyclic group refers to a fused polycyclic aromatic heterocyclic group or a group derived from an aromatic ring assembly.

Z ⁰ , Z ¹ and Z ² are each independently preferably a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, a cyano group, a nitro group, or an alkoxy group having 1 to 12 carbon atoms; ⁰ is more preferably a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or a cyano group, and Z ¹ and Z ² are more preferably a hydrogen atom, a fluorine atom, a chlorine atom, a methyl group, or a cyano group. Moreover, Z ⁰ , Z ¹ and Z ² may contain a polymerizable group.

Q ¹ and Q ² are preferably -NH-, -S-, -NR ^2' -, -O-, and R ^2' is preferably a hydrogen atom. Among them, -S-, -O-, and -NH- are particularly preferred.

Among formulas (Ar-1) to (Ar-23), formulas (Ar-6) and (Ar-7) are preferred from the viewpoint of molecular stability.

In formulas (Ar-16) to (Ar-23), Y ¹ may form an aromatic heterocyclic group together with the nitrogen atom to which it is bonded and Z ⁰ . Examples of the aromatic heterocyclic group include those mentioned above as aromatic heterocycles that Ar may have, such as a pyrrole ring, an imidazole ring, a pyrroline ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, and an indole ring. ring, quinoline ring, isoquinoline ring, purine ring, pyrrolidine ring, etc. This aromatic heterocyclic group may have a substituent. Further, Y ¹ may be the aforementioned optionally substituted polycyclic aromatic hydrocarbon group or polycyclic aromatic heterocyclic group, together with the nitrogen atom to which it is bonded and Z ⁰ . Examples include a benzofuran ring, a benzothiazole ring, a benzoxazole ring, and the like.

式（ＩＩ）中、＊印はＬ^１又はＬ^２との連結部を表す。
Ｄ^１及びＤ^２はそれぞれ独立して、下記一般式（Ｄ－１）から選ばれる基を表す。
置換基Ｘ^１及びＸ^２はそれぞれ独立して、フッ素原子、塩素原子、臭素原子、ヨウ素原子、ペンタフルオロスルフラニル基、ニトロ基、シアノ基、イソシアノ基、アミノ基、ヒドロキシル基、メルカプト基、メチルアミノ基、ジメチルアミノ基、ジエチルアミノ基、ジイソプロピルアミノ基、トリメチルシリル基、ジメチルシリル基、チオイソシアノ基、又は、１個の－ＣＨ_２－又は隣接していない２個以上の－ＣＨ_２－が各々独立して－Ｏ－、－Ｓ－、－ＣＯ－、－ＣＯＯ－、－ＯＣＯ－、－ＣＯ－Ｓ－、－Ｓ－ＣＯ－、－Ｏ－ＣＯ－Ｏ－、－ＣＯ－ＮＨ－、－ＮＨ－ＣＯ－、－ＣＨ＝ＣＨ－ＣＯＯ－、－ＣＨ＝ＣＨ－ＯＣＯ－、－ＣＯＯ－ＣＨ＝ＣＨ－、－ＯＣＯ－ＣＨ＝ＣＨ－、－ＣＨ＝ＣＨ－、－ＣＦ＝ＣＦ－又は－Ｃ≡Ｃ－に置き換えられてもよい炭素数１～２０の直鎖状又は分岐状アルキル基を表す。当該アルキル基中の任意の水素原子はフッ素原子に置換されてもよい。 Examples of compounds satisfying the above characteristics (A) to (D) include compounds in which Ar in the above formula (X) is a group (II) having the following structure.

In formula (II), the * mark represents a connecting portion with L ¹ or L ² .
D ¹ and D ² each independently represent a group selected from the following general formula (D-1).
The substituents X ¹ and X ² are each independently a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a pentafluorosulfuranyl group, a nitro group, a cyano group, an isocyano group, an amino group, a hydroxyl group, a mercapto group, A methylamino group, a dimethylamino group, a diethylamino group, a diisopropylamino group, a trimethylsilyl group, a dimethylsilyl group, a thioisocyano group, or one -CH ₂ - or two or more non-adjacent -CH ₂ - groups, each independently -O-, -S-, -CO-, -COO-, -OCO-, -CO-S-, -S-CO-, -O-CO-O-, -CO-NH-, -NH -CO-, -CH=CH-COO-, -CH=CH-OCO-, -COO-CH=CH-, -OCO-CH=CH-, -CH=CH-, -CF=CF- or -C ≡Represents a straight or branched alkyl group having 1 to 20 carbon atoms which may be replaced with C-. Any hydrogen atom in the alkyl group may be substituted with a fluorine atom.

In the general formula (D-1), M ¹ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. The alkyl group may be substituted with one or more substituents X ³ or may be unsubstituted. Examples of the substituent X ³ include the same groups as those listed for the substituents X ¹ and X ² above.
U ¹ represents an organic group having 2 to 30 carbon atoms and having an aromatic hydrocarbon group. Any carbon atom of the aromatic hydrocarbon group may be substituted with a heteroatom. The aromatic hydrocarbon group may be substituted with one or more of the above substituents X ³ or may be unsubstituted.
T ¹ is -O-, -S-, -COO-, -OCO-, -OCO-O-, -NU ² -, -N=CU ² -, -CO-NU ² -, -OCO-NU ² - or -O-NU ² -. U ² is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, a cycloalkenyl group having 3 to 12 carbon atoms, or an aromatic hydrocarbon group (any of the aromatic hydrocarbon groups) represents an organic group having 2 to 30 carbon atoms (optionally substituted with a hetero atom). Each of the alkyl group, cycloalkyl group, cycloalkenyl group, and aromatic hydrocarbon group may be substituted with one or more of the substituents ^X3 , or may be unsubstituted. The alkyl group may be substituted with the cycloalkyl group or cycloalkenyl group. One -CH ₂ - or two or more non-adjacent -CH ₂ -s in the alkyl group are each independently -O-, -S-, -CO-, -COO-, -OCO- , -CO-S-, -S-CO-, -SO ₂ -, -O-CO-O-, -CO-NH-, -NH-CO-, -CH=CH-COO-, -CH=CH It may be replaced by -OCO-, -COO-CH=CH-, -OCO-CH=CH-, -CH=CH-, -CF=CF- or -C≡C-. One -CH ₂ - or two or more non-adjacent -CH ₂ -s in the cycloalkyl group or cycloalkenyl group are each independently -O-, -CO-, -COO-, -OCO- , or may be replaced with -O-CO-O-. U ¹ and U ² may be combined to form a ring.

In general formula (D-1), M ¹ is preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms which may be substituted with a fluorine atom, and more preferably a hydrogen atom.

U ¹ is preferably an organic group having an aromatic heterocycle in which one or more carbon atoms are substituted with a hetero atom, from the viewpoint of good wavelength dispersion. U ¹ is more preferably an organic group having an aromatic heterocycle that is a condensed ring of a 5-membered ring and a 6-membered ring, since it has good wavelength dispersion and exhibits high birefringence.

Specifically, U ¹ preferably has a group represented by the following formula. In addition, in the following formula, these groups have a bond with T ¹ at an arbitrary position.

T ¹ is preferably -O-, -S-, -N=CU ² - or -NU ² - from the viewpoint of good birefringence and easy synthesis. From the viewpoint of good wavelength dispersion and birefringence, T ¹ is preferably -O-, -S-, or -NU ² -.

Here _, U ² may be substituted by one or more _of the above ^substituents -, -CO-, -COO-, -OCO-, or -O-CO-O-, an alkyl group or alkenyl group having 1 to 20 carbon atoms, or a cycloalkyl group having 3 to 12 carbon atoms. or a cycloalkenyl group having 3 to 12 carbon atoms, or the alkyl group or alkenyl group that may be substituted with the cycloalkyl group, cycloalkenyl group, or aryl group.

Among them, U ² may have a hydrogen atom substituted with a fluorine atom from the viewpoint of birefringence and solvent solubility, and one -CH ₂ - or two or more non-adjacent -CH ₂ - may each be substituted with a fluorine atom. More preferably, it is a straight-chain alkyl group having 2 to 20 carbon atoms which may be independently substituted with -O-, -CO-, -COO- or -OCO-.

U ¹ and U ² may be combined to form a ring. In that case, examples include a cyclic group represented by -NU ¹ U ² or a cyclic group represented by -N=CU ¹ U ² .

From the viewpoint of easy availability of raw materials, good solubility, and high birefringence, D ¹ and D ² each represent a group selected from the following formulas (D-1) to (D-47). is particularly preferred.

At least one kind of polymerizable liquid crystal compound forming the optically anisotropic film is preferably a polymerizable liquid crystal compound having a maximum absorption wavelength between 300 and 400 nm. When the polymerizable liquid crystal composition contains a photopolymerization initiator, there is a possibility that the polymerization reaction and gelation of the polymerizable liquid crystal compound will proceed during long-term storage. However, if the maximum absorption wavelength of the polymerizable liquid crystal compound is 300 to 400 nm, even if it is exposed to ultraviolet light during storage, the generation of reactive species from the photopolymerization initiator and the production of the polymerizable liquid crystal compound by the reactive species. Progress of polymerization reaction and gelation can be effectively suppressed. Therefore, it is advantageous in terms of long-term stability of the polymerizable liquid crystal composition, and it is possible to improve the orientation and uniformity of the film thickness of the optically anisotropic film obtained. Note that the maximum absorption wavelength of the polymerizable liquid crystal compound can be measured in a solvent using an ultraviolet-visible spectrophotometer. The solvent is a solvent that can dissolve the polymerizable liquid crystal compound, and includes, for example, chloroform.

In the present invention, the polymerizable liquid crystal compound forming the optically anisotropic film generally tends to exhibit so-called positive wavelength dispersion as long as the optically anisotropic film obtained has optical properties satisfying formula (2). A compound containing a structure represented by formula (Y) (hereinafter also referred to as "polymerizable liquid crystal compound (Y)") can also be used.

P11-B11-E11-B12-A11-B13- (Y)
[In formula (Y), P11 represents a polymerizable group.
A11 represents a divalent alicyclic hydrocarbon group or a divalent aromatic hydrocarbon group.
B11 is -O-, -S-, -CO-O-, -O-CO-, -O-CO-O-, -CO-NR ¹⁶ -, -NR ¹⁶ -CO-, -CO-, - CS- or a single bond. R ¹⁶ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
B12 and B13 each independently represent -C≡C-, -CH=CH-, -CH ₂ -CH ₂ -, -O-, -S-, -C(=O)-, -C(=O ) -O-, -OC(=O)-, -OC(=O)-O-, -CH=N-, -N=CH-, -N=N-, -C(=O ) -NR ¹⁶ -, -NR ¹⁶ -C(=O)-, -OCH ₂ -, -OCF ₂ -, -CH ₂ O-, -CF ₂ O-, -CH=CH-C(=O)- Represents O-, -OC(=O)-CH=CH-, -H, -C≡N or a single bond.
E11 represents an alkanediyl group having 1 to 12 carbon atoms, the hydrogen atom contained in the alkanediyl group may be substituted with an alkoxy group having 1 to 5 carbon atoms, and the hydrogen atom contained in the alkoxy group may be substituted with a halogen atom. Furthermore, -CH ₂ - constituting the alkanediyl group may be replaced with -O- or -CO-. ]

The number of carbon atoms in the aromatic hydrocarbon group and the alicyclic hydrocarbon group of A11 is preferably in the range of 3 to 18, more preferably in the range of 5 to 12, particularly 5 or 6. preferable. The hydrogen atoms contained in the divalent alicyclic hydrocarbon group and the divalent aromatic hydrocarbon group represented by A11 include a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, It may be substituted with a cyano group or a nitro group, and the hydrogen atom contained in the alkyl group having 1 to 6 carbon atoms and the alkoxy group having 1 to 6 carbon atoms may be substituted with a fluorine atom. As A11, cyclohexane-1,4-diyl group and 1,4-phenylene group are preferable.

E11 is preferably a linear alkanediyl group having 1 to 12 carbon atoms. -CH ₂ - constituting the alkanediyl group may be replaced with -O-.
Specifically, methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane -1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group and dodecane-1,12-diyl group Linear alkanediyl group having 1 to 12 carbon atoms such as diyl group; -CH ₂ -CH ₂ -O-CH ₂ -CH ₂ -, -CH ₂ -CH ₂ -O-CH ₂ -CH ₂ -O- Examples include CH ₂ --CH ₂ -- and --CH ₂ --CH ₂ --O--CH ₂ --CH ₂ --O--CH ₂ --CH ₂ --O--CH ₂ --CH ₂ --.
As B11, -O-, -S-, -CO-O-, and -O-CO- are preferable, and -CO-O- is especially preferable.
B12 and B13 are each independently -O-, -S-, -C(=O)-, -C(=O)-O-, -O-C(=O)-, -O-C (=O)-O- is preferred, and -O- or -OC(=O)-O- is particularly preferred.

［式（Ｐ－１１）～（Ｐ－１５）中、
Ｒ^１７～Ｒ^２１はそれぞれ独立に、炭素数１～６のアルキル基又は水素原子を表わす。］ The polymerizable group represented by P11 is preferably a radically polymerizable group or a cationically polymerizable group in terms of high polymerization reactivity, particularly photopolymerization reactivity, and is easy to handle and also easy to produce a liquid crystal compound. Therefore, the polymerizable group is preferably a group represented by the following formulas (P-11) to (P-15).

[In formulas (P-11) to (P-15),
R ¹⁷ to R ²¹ each independently represent an alkyl group having 1 to 6 carbon atoms or a hydrogen atom. ]

Specific examples of the groups represented by formulas (P-11) to (P-15) include groups represented by formulas (P-16) to (P-20) below.

P11 is preferably a group represented by formula (P-14) to formula (P-20), and more preferably a vinyl group, p-stilbene group, epoxy group or oxetanyl group.
More preferably, the group represented by P11-B11- is an acryloyloxy group or a methacryloyloxy group.

Examples of the polymerizable liquid crystal compound (Y) include compounds represented by formula (I), formula (II), formula (III), formula (IV), formula (V), or formula (VI).
P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-A14-B16-E12-B17-P12 (I)
P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-A14-F11 (II)
P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-E12-B17-P12 (III)
P11-B11-E11-B12-A11-B13-A12-B14-A13-F11 (IV)
P11-B11-E11-B12-A11-B13-A12-B14-E12-B17-P12 (V)
P11-B11-E11-B12-A11-B13-A12-F11 (VI)
[In the formula,
A11, B11 to B13 and P11 have the same meanings as above,
A12 to A14 are each independently synonymous with A11, B14 to B16 are each independently synonymous with B12, B17 is synonymous with B11, E12 is synonymous with E11, and P12 is synonymous with P11. be.
F11 is a hydrogen atom, an alkyl group having 1 to 13 carbon atoms, an alkoxy group having 1 to 13 carbon atoms, a cyano group, a nitro group, a trifluoromethyl group, a dimethylamino group, a hydroxy group, a methylol group, a formyl group, a sulfo group (-SO ₃ H) represents a carboxyl group, an alkoxycarbonyl group having 1 to 10 carbon atoms, or a halogen atom, and -CH ₂ - constituting the alkyl group and alkoxy group may be replaced with -O-. good. ]

Specific examples of the polymerizable liquid crystal compound (Y) include "3.8.6 Network (fully crosslinked type )", "6.5.1 Liquid crystal material b. Polymerizable nematic liquid crystal material" compounds having a polymerizable group, JP 2010-31223A, JP 2010-270108A, Examples include polymerizable liquid crystal compounds described in JP-A No. 2011-6360 and JP-A No. 2011-207765.

The content of the polymerizable liquid crystal compound in the polymerizable liquid crystal composition is, for example, 70 to 99.5 parts by mass, preferably 80 to 99 parts by mass, based on 100 parts by mass of the solid content of the polymerizable liquid crystal composition. The amount is preferably 85 to 98 parts by weight, and even more preferably 90 to 95 parts by weight. It is advantageous that the content of the polymerizable liquid crystal compound is within the above range because the orientational order of the optically anisotropic film obtained is likely to be improved. In addition, when the polymerizable liquid crystal composition contains a plurality of polymerizable liquid crystal compounds, it is preferable that the total mass of all the polymerizable liquid crystal compounds contained in the polymerizable liquid crystal composition is within the above content range. Moreover, the solid content of the polymerizable liquid crystal composition means all the components excluding volatile components such as organic solvents from the polymerizable liquid crystal composition.

In addition to the polymerizable liquid crystal compound, the polymerizable liquid crystal composition used to form the optically anisotropic film further contains additives such as a solvent, a photopolymerization initiator, a leveling agent, an antioxidant, and a photosensitizer. You can stay there. These components may be used alone or in combination of two or more.

Since the polymerizable liquid crystal composition for forming an optically anisotropic film is usually applied to a substrate etc. in a state dissolved in a solvent, it preferably contains a solvent. The solvent is preferably a solvent that has high solubility for the polymerizable liquid crystal compound used and is inert to the polymerization reaction of the polymerizable liquid crystal compound. Examples of solvents include alcohols such as water, methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether, 1-methoxy-2-propanol, 2-butoxyethanol, and propylene glycol monomethyl ether. Solvents: Ester solvents such as ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone, propylene glycol methyl ether acetate and ethyl lactate; Acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone and methyl isobutyl ketone, etc. Ketone solvents; aliphatic hydrocarbon solvents such as pentane, hexane and heptane; alicyclic hydrocarbon solvents such as ethylcyclohexane; aromatic hydrocarbon solvents such as toluene and xylene; nitrile solvents such as acetonitrile; such as tetrahydrofuran and dimethoxyethane. Ether solvents; chlorine-containing solvents such as chloroform and chlorobenzene; amide solvents such as dimethylacetamide, dimethylformamide, N-methyl-2-pyrrolidone (NMP), and 1,3-dimethyl-2-imidazolidinone, etc. It will be done. These solvents can be used alone or in combination. Among these, alcohol solvents, ester solvents, ketone solvents, chlorine-containing solvents, amide solvents, and aromatic hydrocarbon solvents are preferred.

The content of the solvent in the polymerizable liquid crystal composition is preferably 50 to 98 parts by weight, more preferably 70 to 95 parts by weight, based on 100 parts by weight of the polymerizable liquid crystal composition. Therefore, the solid content in 100 parts by mass of the polymerizable liquid crystal composition is preferably 2 to 50 parts by mass. When the solid content is 50 parts by mass or less, the viscosity of the polymerizable liquid crystal composition tends to be low, so the thickness of the film tends to be substantially uniform and unevenness tends to occur less easily. The solid content can be determined as appropriate in consideration of the thickness of the cured liquid crystal film to be produced.

A polymerization initiator is a compound that generates reactive species by the contribution of heat or light and can initiate a polymerization reaction of a polymerizable liquid crystal compound or the like. Examples of reactive species include radicals, cations, anions, and the like. Among them, from the viewpoint of easy reaction control, a photopolymerization initiator that generates radicals upon irradiation with light is preferred.

Examples of the photopolymerization initiator include benzoin compounds, benzophenone compounds, benzyl ketal compounds, α-hydroxyketone compounds, α-aminoketone compounds, triazine compounds, iodonium salts, and sulfonium salts. Specifically, Irgacure (registered trademark) 907, Irgacure 184, Irgacure 651, Irgacure 819, Irgacure 250, Irgacure 369, Irgacure 379, Irgacure 127, Irgacure 2959, Irgacure 754, Irgacure 379EG (the above, BASF Japan Ltd. ), Seiqual BZ, Seiqual Z, Seiqual BEE (manufactured by Seiko Kagaku Co., Ltd.), Kayacure BP100 (manufactured by Nippon Kayaku Co., Ltd.), Kayacure UVI-6992 (manufactured by Dow), Adeka Optomer SP- 152, ADEKA OPTOMER SP-170, ADEKA OPTOMER N-1717, ADEKA OPTOMER N-1919, ADEKA ARCLES NCI-831, ADEKA ARCLES NCI-930 (manufactured by ADEKA Co., Ltd.), TAZ-A, TAZ -PP (manufactured by Nippon Siberhegner Co., Ltd.) and TAZ-104 (manufactured by Sanwa Chemical Co., Ltd.).
In the polymerizable liquid crystal composition for forming an optically anisotropic film, the photopolymerization initiators can be used alone or in combination of two or more.

The photopolymerization initiator can fully utilize the energy emitted from the light source and has excellent productivity, so it is preferable that the maximum absorption wavelength is 300 nm to 400 nm, more preferably 300 nm to 380 nm. Among them, α-acetophenone type Polymerization initiators and oxime photopolymerization initiators are preferred.

As α-acetophenone compounds, 2-methyl-2-morpholino-1-(4-methylsulfanylphenyl)propan-1-one, 2-dimethylamino-1-(4-morpholinophenyl)-2-benzylbutane-1 -one and 2-dimethylamino-1-(4-morpholinophenyl)-2-(4-methylphenylmethyl)butan-1-one, and more preferably 2-methyl-2-morpholino-1-( Examples include 4-methylsulfanylphenyl)propan-1-one and 2-dimethylamino-1-(4-morpholinophenyl)-2-benzylbutan-1-one. Commercially available α-acetophenone compounds include Irgacure 369, 379EG, 907 (manufactured by BASF Japan Co., Ltd.) and Seiqual BEE (manufactured by Seiko Kagaku Co., Ltd.).

Oxime-based photopolymerization initiators generate radicals such as phenyl radicals and methyl radicals when irradiated with light. The polymerization of the polymerizable liquid crystal compound progresses suitably with these radicals, and among them, oxime-based photopolymerization initiators that generate methyl radicals are preferred because they have a high initiation efficiency of the polymerization reaction. Furthermore, from the viewpoint of allowing the polymerization reaction to proceed more efficiently, it is preferable to use a photopolymerization initiator that can efficiently utilize ultraviolet light having a wavelength of 350 nm or more. As a photopolymerization initiator that can efficiently utilize ultraviolet light with a wavelength of 350 nm or more, triazine compounds and carbazole compounds containing an oxime ester structure are preferred, and carbazole compounds containing an oxime ester structure are more preferred from the viewpoint of sensitivity. Examples of carbazole compounds containing an oxime ester structure include 1,2-octanedione, 1-[4-(phenylthio)-2-(O-benzoyloxime)], ethanone, 1-[9-ethyl-6-(2- Examples include methylbenzoyl)-9H-carbazol-3-yl]-1-(O-acetyloxime). Commercially available oxime ester photopolymerization initiators include Irgacure OXE-01, Irgacure OXE-02, Irgacure OXE-03 (manufactured by BASF Japan Co., Ltd.), Adeka Optomer N-1919, and Adeka Arcles NCI-831. (All of the above are manufactured by ADEKA Co., Ltd.).

The content of the photopolymerization initiator is usually 0.1 to 30 parts by mass, preferably 1 to 20 parts by mass, and more preferably 1 to 15 parts by mass, per 100 parts by mass of the polymerizable liquid crystal compound. It is. Within the above range, the reaction of the polymerizable groups will proceed sufficiently and the orientation of the polymerizable liquid crystal compound will not be easily disturbed.

A leveling agent is an additive that has the function of adjusting the fluidity of a polymerizable liquid crystal composition and making the coating film obtained by applying the composition more flat. Examples include fluoroalkyl leveling agents. Commercial products may be used as the leveling agent, and specifically, DC3PA, SH7PA, DC11PA, SH28PA, SH29PA, SH30PA, ST80PA, ST86PA, SH8400, SH8700, FZ2123 (all manufactured by Dow Corning Toray Co., Ltd.) , KP321, KP323, KP324, KP326, KP340, KP341, 4452, TSF4460 Fluorinert (registered trademark) FC-72, fluorinert FC-40, FC-43, FC-3283 (all manufactured by Sumitomo 3M Ltd.) ), Megafac (registered trademark) R-08, R-30, R-90, F-410, F-411, F-443, F-445, F-470, F- 477, F-479, F-482, F-483 (all manufactured by DIC Corporation), EFTOP (product name) EF301, EF303, EF351, EF352 (all manufactured by Mitsubishi Materials) Denshi Kasei Co., Ltd.), Surflon (registered trademark) S-381, S-382, S-383, S-393, SC-101, SC-105, KH-40, SA-100 ( All of the above products are manufactured by AGC Seimi Chemical Co., Ltd.), product name E1830, product name E5844 (manufactured by Daikin Fine Chemical Laboratory Co., Ltd.), BM-1000, BM-1100, BYK-352, BYK-353 and BYK-361N (all products are manufactured by AGC Seimi Chemical Co., Ltd.). (trade name: manufactured by BM Chemie), etc. Leveling agents can be used alone or in combination of two or more.

The content of the leveling agent is preferably 0.01 to 5 parts by weight, more preferably 0.05 to 3 parts by weight, based on 100 parts by weight of the polymerizable liquid crystal compound. It is preferable that the content of the leveling agent is within the above range because it is easy to orient the polymerizable liquid crystal compound and the resulting cured liquid crystal film tends to be smoother.

By blending a polymerization inhibitor, the polymerization reaction of the polymerizable liquid crystal compound can be controlled. Examples of polymerization inhibitors include phenolic compounds such as BHT, hydroquinone, alkoxy group-containing hydroquinone, alkoxy group-containing catechol (for example, butylcatechol, etc.), pyrogallol, 2,2,6,6-tetramethyl-1-pyroquinone, etc. Examples include radical scavengers such as peridinyloxy radical; thiophenols; β-naphthylamines and β-naphthols.

From the viewpoint of polymerizing the polymerizable liquid crystal compound without disturbing the orientation of the polymerizable liquid crystal compound, the content of the polymerization inhibitor is usually 0.01 to 10 parts by mass with respect to 100 parts by mass of the polymerizable liquid crystal compound. , preferably 0.1 to 5 parts by weight, more preferably 0.1 to 3 parts by weight. Polymerization inhibitors can be used alone or in combination of two or more.

By using a photosensitizer, the sensitivity of the photopolymerization initiator can be increased. Examples of the photosensitizer include xanthone such as xanthone and thioxanthone; anthracenes having substituents such as anthracene and alkyl ether; phenothiazine; and rubrene. The photosensitizers can be used alone or in combination of two or more. The content of the photosensitizer is usually 0.01 to 10 parts by weight, preferably 0.05 to 5 parts by weight, and more preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the polymerizable liquid crystal compound. 3 parts by mass.

The polymerizable liquid crystal composition can be prepared by stirring a polymerizable liquid crystal compound and components other than the polymerizable liquid crystal compound, such as a solvent and a photopolymerization initiator, at a predetermined temperature.

In the present invention, the optically anisotropic film made of a horizontally aligned liquid crystal cured film is, for example,
A step of forming a coating film of a polymerizable liquid crystal composition for forming an optically anisotropic film and orienting the polymerizable liquid crystal compound in a desired direction (horizontal direction) with respect to the plane of the coating film (hereinafter referred to as "coating film"). (also referred to as “formation process”),
a step of drying the paint film to form a dry paint film (hereinafter also referred to as "drying step");
A step of irradiating the dry coating film with active energy rays and curing the polymerizable liquid crystal composition while maintaining the orientation state of the polymerizable liquid crystal compound to obtain a cured liquid crystal film (hereinafter also referred to as "curing step");
Step of immersing the obtained cured liquid crystal film in a solvent (hereinafter also referred to as "solvent immersion step")
It can be manufactured by a method including.

The coating film of the polymerizable liquid crystal composition can be formed by applying the polymerizable liquid crystal composition onto a substrate or an alignment film described below.
Examples of the base material include glass base materials and film base materials, but resin film base materials are preferred from the viewpoint of processability. Examples of the resin constituting the film base material include polyolefins such as polyethylene, polypropylene, and norbornene polymers; cyclic olefin resins; polyvinyl alcohol; polyethylene terephthalate; polymethacrylic esters; polyacrylic esters; triacetyl cellulose; Cellulose esters such as diacetyl cellulose and cellulose acetate propionate; polyethylene naphthalate; polycarbonate; polysulfone; polyether sulfone; polyether ketone; plastics such as polyphenylene sulfide and polyphenylene oxide. Such a resin can be used as a base material by forming a film by known means such as a solvent casting method and a melt extrusion method. The surface of the base material may have a protective layer formed from acrylic resin, methacrylic resin, epoxy resin, oxetane resin, urethane resin, melamine resin, etc., and may be subjected to mold release treatment such as silicone treatment, corona treatment, Surface treatment such as plasma treatment may be performed.

Commercially available products may be used as the base material. Commercially available cellulose ester base materials include, for example, cellulose ester base materials manufactured by Fuji Photo Film Co., Ltd. such as Fuji Tac film; manufactured by Konica Minolta Opto Co., Ltd. such as "KC8UX2M", "KC8UY", and "KC4UY"; Examples include cellulose ester base materials. Commercially available cyclic olefin resins include, for example, cyclic olefin resins manufactured by Ticona (Germany) such as "Topas (registered trademark)"; cyclic olefin resins manufactured by JSR Corporation such as "Arton (registered trademark)"; Cyclic olefin resins manufactured by Nippon Zeon Co., Ltd. such as “ZEONOR (registered trademark)” and “ZEONEX (registered trademark)”; Mitsui resins such as “APEL” (registered trademark) Examples include cyclic olefin resin manufactured by Kagaku Corporation. A commercially available cyclic olefin resin base material can also be used. Commercially available cyclic olefin resin base materials include cyclic olefin resin base materials manufactured by Sekisui Chemical Co., Ltd. such as "Escina (registered trademark)" and "SCA40 (registered trademark)"; "Zeonor Film (registered trademark)" Examples include cyclic olefin resin base materials manufactured by Optes Co., Ltd.; and cyclic olefin resin base materials manufactured by JSR Corporation such as "Arton Film (registered trademark)".

From the viewpoints of thinning of the optical film including the optically anisotropic film, ease of peeling of the base material, ease of handling of the base material, etc., the thickness of the base material is usually 5 to 300 μm, preferably 10 to 150 μm. be.

Methods for applying the polymerizable liquid crystal composition to a substrate include coating methods such as spin coating, extrusion, gravure coating, die coating, bar coating, and applicator methods, and printing methods such as flexography. For example, known methods such as

By forming a coating film of a polymerizable liquid crystal compound on the alignment film, the polymerizable liquid crystal compound can be aligned with high precision. The alignment film has an alignment regulating force that causes the polymerizable liquid crystal compound to align the liquid crystal in a desired direction. For example, by using an alignment film (hereinafter also referred to as "horizontal alignment film") that has an alignment regulating force that horizontally aligns a polymerizable liquid crystal compound, optical An anisotropic film can be obtained. The alignment regulating force can be adjusted arbitrarily depending on the type of alignment film, surface condition, rubbing conditions, etc., and if the alignment film is made of a photo-alignable polymer, it can be adjusted arbitrarily by changing the polarized light irradiation conditions, etc. It is possible to do so.

The alignment film is preferably one that has a solvent resistance that does not dissolve when the polymerizable liquid crystal composition is applied, etc., and also has heat resistance in heat treatment for removing the solvent and aligning the polymerizable liquid crystal compound as described below. Examples of the alignment film include an alignment film containing an alignment polymer, a photo-alignment film, a groove alignment film having a concavo-convex pattern or a plurality of grooves on the surface, and a stretched film stretched in the alignment direction. A photo-alignment film is preferred from the viewpoint of quality.

Examples of oriented polymers include polyamides and gelatins having an amide bond in the molecule, polyimide having an imide bond in the molecule, polyamic acid which is a hydrolyzate thereof, polyvinyl alcohol, alkyl-modified polyvinyl alcohol, polyacrylamide, polyacrylamide, etc. Examples include oxazole, polyethyleneimine, polystyrene, polyvinylpyrrolidone, polyacrylic acid and polyacrylic esters. Among them, polyvinyl alcohol is preferred. The oriented polymers can be used alone or in combination of two or more.

An oriented film containing an oriented polymer is usually prepared by applying a composition in which an oriented polymer is dissolved in a solvent (hereinafter sometimes referred to as an "oriented polymer composition") to a base material, and then removing the solvent, or It is obtained by applying an oriented polymer composition to a base material, removing the solvent, and rubbing it (rubbing method). Examples of the solvent include the same solvents as those exemplified above as solvents that can be used in the polymerizable liquid crystal composition.

The concentration of the oriented polymer in the oriented polymer composition may be within a range that allows the oriented polymer material to be completely dissolved in the solvent, but it is preferably 0.1 to 20% in terms of solid content with respect to the solution. It is more preferably about .1 to 10%.

Commercially available alignment film materials may be used as they are as the alignment polymer composition. Commercially available alignment film materials include Sunever (registered trademark, manufactured by Nissan Chemical Industries, Ltd.), Optomer (registered trademark, manufactured by JSR Corporation), and the like.

Examples of the method for applying the oriented polymer composition to the substrate include the same methods as those exemplified as the method for applying the polymerizable liquid crystal composition to the substrate.

Examples of methods for removing the solvent contained in the oriented polymer composition include natural drying, ventilation drying, heating drying, and reduced pressure drying.

In order to impart an alignment regulating force to the alignment film, rubbing treatment can be performed as necessary (rubbing method). As a method of imparting an orientation regulating force by a rubbing method, a rubbing cloth is wrapped around a rotating rubbing roll, and an oriented polymer composition is applied to a substrate and annealed to form an oriented polymer composition on the surface of the substrate. Examples include a method of bringing oriented polymer films into contact with each other. If masking is performed when performing the rubbing process, a plurality of regions (patterns) with different orientation directions can be formed on the alignment film.

A photo-alignment film is usually produced by coating a base material with a composition containing a polymer or monomer having a photo-reactive group and a solvent (hereinafter also referred to as "composition for forming a photo-alignment film"), and after removing the solvent, polarized light is produced. (preferably polarized UV). The photo-alignment film is also advantageous in that the direction of the alignment regulating force can be arbitrarily controlled by selecting the polarization direction of the polarized light to be irradiated.

The photoreactive group refers to a group that produces liquid crystal alignment ability when irradiated with light. Specifically, groups that are involved in photoreactions that are the origin of liquid crystal alignment ability, such as orientation induction of molecules caused by light irradiation, or isomerization reactions, dimerization reactions, photocrosslinking reactions, or photodecomposition reactions, can be mentioned. Among these, groups that participate in a dimerization reaction or a photocrosslinking reaction are preferable because they have excellent orientation. The photoreactive group is preferably a group having an unsaturated bond, especially a double bond, such as a carbon-carbon double bond (C=C bond), a carbon-nitrogen double bond (C=N bond), or a nitrogen-nitrogen double bond. Particularly preferred is a group having at least one selected from the group consisting of a double bond (N=N bond) and a carbon-oxygen double bond (C=O bond).

Examples of the photoreactive group having a C═C bond include a vinyl group, a polyene group, a stilbene group, a stilbazole group, a stilbazolium group, a chalcone group, and a cinnamoyl group. Examples of the photoreactive group having a C=N bond include groups having structures such as an aromatic Schiff base and an aromatic hydrazone. Examples of the photoreactive group having an N=N bond include an azobenzene group, an azonaphthalene group, an aromatic heterocyclic azo group, a bisazo group, a formazan group, and a group having an azoxybenzene structure. Examples of the photoreactive group having a C═O bond include a benzophenone group, a coumarin group, an anthraquinone group, and a maleimide group. These groups may have substituents such as an alkyl group, an alkoxy group, an aryl group, an allyloxy group, a cyano group, an alkoxycarbonyl group, a hydroxyl group, a sulfonic acid group, and a halogenated alkyl group.

Among these, photoreactive groups that participate in photodimerization reactions are preferred, since the amount of polarized light irradiation required for photoalignment is relatively small, and it is easy to obtain a photoalignment film with excellent thermal stability and stability over time. Cinnamoyl and chalcone groups are preferred. As the polymer having a photoreactive group, one having a cinnamoyl group such that the end of the polymer side chain has a cinnamic acid structure is particularly preferred.

By applying the composition for forming a photo-alignment film onto a base material, a photo-alignment inducing layer can be formed on the base material. The solvent contained in the composition may be the same as the solvents listed above as solvents that can be used in the polymerizable liquid crystal composition, and can be appropriately selected depending on the solubility of the polymer or monomer having a photoreactive group. can do.

The content of the polymer or monomer having a photoreactive group in the composition for forming a photo-alignment film can be adjusted as appropriate depending on the type of polymer or monomer and the desired thickness of the photo-alignment film. The amount is preferably at least 0.2% by weight, more preferably from 0.3 to 10% by weight. The composition for forming a photo-alignment film may contain a polymeric material such as polyvinyl alcohol or polyimide, and a photosensitizer as long as the properties of the photo-alignment film are not significantly impaired.

Examples of the method for applying the photo-alignment film-forming composition to the substrate include the same method as the method for applying the alignment polymer composition to the substrate. Examples of methods for removing the solvent from the applied composition for forming a photoalignment film include natural drying, ventilation drying, heat drying, and reduced pressure drying.

In order to irradiate polarized light, polarized UV can be irradiated directly onto the composition for forming a photo-alignment film coated on the substrate, from which the solvent has been removed, or the polarized light can be irradiated from the substrate side and the polarized light can be transmitted. It may also be a form of irradiation. Moreover, it is particularly preferable that the polarized light is substantially parallel light. The wavelength of the polarized light to be irradiated is preferably in a wavelength range in which a photoreactive group of a polymer or monomer having a photoreactive group can absorb light energy. Specifically, UV (ultraviolet light) having a wavelength in the range of 250 to 400 nm is particularly preferred. Examples of light sources used for the polarized light irradiation include xenon lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, and ultraviolet lasers such as KrF and ArF. preferable. Among these, high-pressure mercury lamps, ultra-high-pressure mercury lamps, and metal halide lamps are preferable because they emit a high intensity of ultraviolet light with a wavelength of 313 nm. Polarized UV can be irradiated by passing the light from the light source through a suitable polarizer. As such a polarizer, a polarizing filter, a polarizing prism such as Glan-Thompson or Glan-Taylor, or a wire grid type polarizer can be used.

If masking is performed when performing rubbing or polarized light irradiation, it is also possible to form a plurality of regions (patterns) with different directions of liquid crystal alignment.

A groove alignment film is a film having an uneven pattern or a plurality of grooves on the film surface. When a polymerizable liquid crystal compound is applied to a film having a plurality of linear grooves arranged at equal intervals, liquid crystal molecules are aligned in the direction along the grooves.

The groove alignment film can be obtained by exposing the surface of a photosensitive polyimide film to light through an exposure mask having pattern-shaped slits, followed by development and rinsing to form a concavo-convex pattern, and by using a plate with grooves on the surface. A method of forming a layer of uncured UV curable resin on a shaped master, transferring the formed resin layer to a base material, and then curing it; Examples include a method in which a rolled master having a plurality of grooves is pressed against each other to form irregularities, and then hardened.

The thickness of the alignment film (orientation film containing an alignment polymer or photo-alignment film) is usually in the range of 10 to 10,000 nm, preferably in the range of 10 to 1,000 nm, more preferably in the range of 10 to 500 nm, and even more preferably is in the range of 10 to 300 nm, particularly preferably 50 to 250 nm.

A dry coating film is formed by removing the solvent from the coating film obtained in the coating film forming step by drying or the like. Examples of the drying method include natural drying, ventilation drying, heating drying, and reduced pressure drying. At this time, by heating the coating film obtained from the polymerizable liquid crystal composition, the solvent is dried and removed from the coating film, and the polymerizable liquid crystal compound is oriented in the desired direction (horizontal direction) with respect to the plane of the coating film. can be done. The heating temperature of the coating film can be appropriately determined by considering the polymerizable liquid crystal compound used and the material of the base material forming the coating film. A temperature above the transition temperature is usually required. In order to bring the polymerizable liquid crystal compound into a horizontal alignment state while removing the solvent contained in the polymerizable liquid crystal composition, for example, the liquid crystal phase transition temperature (smectic phase transition temperature) of the polymerizable liquid crystal compound contained in the polymerizable liquid crystal composition is or nematic phase transition temperature).
Note that the liquid crystal phase transition temperature can be measured using, for example, a polarizing microscope equipped with a temperature control stage, a differential scanning calorimeter (DSC), a thermogravimetric differential thermal analyzer (TG-DTA), or the like. In addition, when two or more types of polymerizable liquid crystal compounds are used in combination, the above phase transition temperature is determined by the polymerization temperature when all the polymerizable liquid crystal compounds constituting the polymerizable liquid crystal composition are mixed in the same ratio as the composition in the polymerizable liquid crystal composition. It means the temperature measured using a mixture of polymerizable liquid crystal compounds in the same manner as when using one type of polymerizable liquid crystal compound. It is generally known that the liquid crystal phase transition temperature of the polymerizable liquid crystal compound in the polymerizable liquid crystal composition may be lower than the liquid crystal phase transition temperature of the polymerizable liquid crystal compound alone.

The heating time can be appropriately determined depending on the heating temperature, the type of polymerizable liquid crystal compound used, the type of solvent, its boiling point, its amount, etc., but is usually 15 seconds to 10 minutes, preferably 0.5 to 10 minutes. It's 5 minutes.

Removal of the solvent from the coating film may be performed simultaneously with heating the polymerizable liquid crystal compound to a temperature equal to or higher than the liquid crystal phase transition temperature, or may be performed separately, but it is preferably performed simultaneously from the viewpoint of improving productivity. Before heating the polymerizable liquid crystal compound to a temperature higher than the liquid crystal phase transition temperature, the solvent in the coating film obtained from the polymerizable liquid crystal composition is adjusted to an appropriate level under conditions such that the polymerizable liquid crystal compound contained in the coating film obtained from the polymerizable liquid crystal composition does not polymerize. A preliminary drying step for removal may be provided. Drying methods in this pre-drying step include natural drying, ventilation drying, heat drying, reduced pressure drying, etc. The drying temperature (heating temperature) in this drying step depends on the type of polymerizable liquid crystal compound used and the solvent. It can be determined as appropriate depending on the type, boiling point, amount, etc.

In the dry coating film obtained in the drying step, a cured liquid crystal film is formed by polymerizing the polymerizable liquid crystal compound while maintaining the orientation state of the polymerizable liquid crystal compound. Examples of the polymerization method include a thermal polymerization method and a photopolymerization method, and the photopolymerization method is preferable from the viewpoint of easy control of the polymerization reaction. In photopolymerization, the light irradiated to the dry coating film depends on the type of photopolymerization initiator contained in the dry coating film, the type of polymerizable liquid crystal compound (especially the type of polymerizable group possessed by the polymerizable liquid crystal compound) and the amount thereof is appropriately selected. Specific examples include one or more types of light selected from the group consisting of visible light, ultraviolet light, infrared light, X-rays, α-rays, β-rays, and γ-rays, and active energy rays such as active electron beams. . Among these, ultraviolet light is preferable because it is easy to control the progress of the polymerization reaction and it is possible to use photopolymerization equipment that is widely used in the field. It is preferable to select the type of polymerizable liquid crystal compound and photopolymerization initiator contained in the polymerizable liquid crystal composition. Moreover, during polymerization, the polymerization temperature can also be controlled by irradiating the dry coating film with light while cooling it with an appropriate cooling means. By employing such a cooling means and polymerizing the polymerizable liquid crystal compound at a lower temperature, a cured liquid crystal film can be appropriately formed even if a base material with relatively low heat resistance is used. It is also possible to promote the polymerization reaction by increasing the polymerization temperature within a range that does not cause problems due to heat during light irradiation (such as deformation of the base material due to heat). A patterned cured film can also be obtained by performing masking or development during photopolymerization.

Examples of the light source of the active energy ray include a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a xenon lamp, a halogen lamp, a carbon arc lamp, a tungsten lamp, a gallium lamp, an excimer laser, and a wavelength range. Examples include an LED light source that emits light in the range of 380 to 440 nm, a chemical lamp, a black light lamp, a microwave-excited mercury lamp, and a metal halide lamp.

The ultraviolet irradiation intensity is usually 10 to 3,000 mW/cm ² . The ultraviolet irradiation intensity is preferably an intensity in a wavelength range effective for activating the photopolymerization initiator. The time for irradiating the light is usually 0.1 seconds to 10 minutes, preferably 0.1 seconds to 5 minutes, more preferably 0.1 seconds to 3 minutes, and even more preferably 0.1 seconds to 1 minute. be. When irradiated once or multiple times with such ultraviolet irradiation intensity, the cumulative amount of light is 10 to 3,000 mJ/cm ² , preferably 50 to 2,000 mJ/cm ² , more preferably 100 to 1,000 mJ/cm It is ² .

The step of immersing the cured liquid crystal film obtained in the curing process in a solvent is performed by adjusting the refractive index nyA in the direction perpendicular to the direction of nxA within the plane of the optically anisotropic film obtained, and the This is one effective treatment method for controlling the orientation of the polymerizable liquid crystal compound so that the ratio of the refractive index nzA in the direction perpendicular to the plane satisfies the formula (1). Through this process, the molecules of the polymerizable liquid crystal compound constituting the cured liquid crystal film, especially the polymerizable liquid crystal compound having the above-mentioned T-shaped structure that can exhibit reverse wavelength dispersion when cured, are It is thought that movement occurs more easily, and the constituent molecules arranged in a direction intersecting the long axis direction of the polymerizable liquid crystal compound tend to orient in a certain direction. Thereby, it becomes possible to control the directionality (orientation) of the constituent molecules of the polymerizable liquid crystal compound and to set the ratio of the refractive index nyA(λ) to the refractive index nzA(λ) within the above-mentioned specific range.

The solvent used in the solvent immersion step can be appropriately determined depending on the polymerizable liquid crystal compound used, the type of base material, etc. Specifically, examples of the solvent that can be used in the polymerizable liquid crystal composition for forming an optically anisotropic film include the same solvents as those exemplified above. Among these, alcohol solvents, ester solvents, ketone solvents, chlorine-containing solvents, amide solvents, and aromatic hydrocarbon solvents are preferable, it is more preferable that ketone solvents are included, it is even more preferable that ketone solvents containing a cyclic structure are included, and cyclic It is particularly preferable to include anone, and particularly preferably to include cyclohexanone. As the solvent for the solvent dipping step, one type may be used alone, or two or more types may be used in combination. The solvent used in the solvent dipping step and the solvent constituting the polymerizable liquid crystal composition may be the same or different. It is preferable to use the same solvent as the solvent constituting the polymerizable liquid crystal composition in the solvent dipping step from the viewpoint of solubility of the polymerizable liquid crystal compound. On the other hand, as a solvent for the solvent immersion process, considering the influence on the base material used for forming the optically anisotropic film, it is necessary to select a solvent that has appropriate solubility for the polymerizable liquid crystal compound used, and is suitable for the base material used. It is preferable to select a solvent that has little influence on (does not dissolve the base material).

Conditions such as the solvent temperature and immersion time in the solvent immersion step depend on the type of polymerizable liquid crystal compound used, the type of solvent, the degree of polymerization of the cured liquid crystal film, etc., and the refractive index nyA ( The ratio between λ) and nzA(λ) can be appropriately determined so as to satisfy Expression (1). For example, when producing an optically anisotropic film continuously, the solvent temperature is preferably 10°C or higher, more preferably 15°C or higher, still more preferably 20°C or higher, and preferably 50°C or lower. , more preferably 45°C or lower, still more preferably 35°C or lower. The immersion time is preferably at least 10 seconds, more preferably at least 20 seconds, even more preferably at least 30 seconds, and is preferably at most 600 seconds, more preferably at most 550 seconds, even more preferably at most 500 seconds. be.

After the solvent immersion step, the liquid crystal cured film immersed in the solvent is dried to remove the solvent, thereby obtaining an optically anisotropic film made of the liquid crystal cured film. The cured liquid crystal film can be dried by natural drying, ventilation drying, heating drying, reduced pressure drying, or the like.

The thickness of the optically anisotropic film can be appropriately selected depending on the display device to which it is applied. For example, it may be from 0.1 to 300 μm, preferably from 0.5 μm to 100 μm, more preferably from 0.5 μm to 50 μm. When the optically anisotropic film is composed of a horizontally aligned liquid crystal cured film, its thickness is preferably 0.5 μm or more, more preferably 0.8 μm or more, even more preferably 1.0 μm or more, and preferably 10 μm. The thickness is more preferably 5 μm or less, further preferably 4 μm or less, particularly preferably 3.5 μm or less.

The present invention includes an optical film containing the optically anisotropic film of the present invention. In an embodiment, the optical film of the present invention includes a base material and the optically anisotropic film of the present invention laminated on the base material with or without an alignment film. In the optical film of the present invention, the base material may be releasable.

The optical film of the present invention may contain layers other than the optically anisotropic film, the base material, and the alignment film of the present invention as long as the effects of the present invention are not affected. Such other layers include, for example, a vertically aligned retardation layer, a cured resin layer for the purpose of increasing or reinforcing the mechanical strength of the cured liquid crystal film, a hard coat layer, an overcoat layer, and a adhesive layer. Examples include an adhesive layer and a primer layer.

The present invention includes an elliptically polarizing plate including the optically anisotropic film of the present invention and a polarizing film.
The polarizing film is a film having a polarizing function, and includes a stretched film on which a dye having absorption anisotropy is adsorbed, a film containing a film coated with a dye having absorption anisotropy as a polarizer, and the like. Examples of dyes having absorption anisotropy include dichroic dyes.

A film containing a stretched film adsorbed with a dye having absorption anisotropy as a polarizer is usually produced by a process of uniaxially stretching a polyvinyl alcohol resin film or by dyeing the polyvinyl alcohol resin film with a dichroic dye. A polarizer manufactured through the steps of adsorbing a dichroic dye, treating a polyvinyl alcohol resin film with the dichroic dye adsorbed with an aqueous boric acid solution, and washing with water after treatment with an aqueous boric acid solution. It is made by sandwiching a transparent protective film on one side with an adhesive between them.

Polyvinyl alcohol resin is obtained by saponifying polyvinyl acetate resin. As the polyvinyl acetate resin, in addition to polyvinyl acetate, which is a homopolymer of vinyl acetate, a copolymer of vinyl acetate and another monomer copolymerizable therewith can be used. Examples of other monomers copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and acrylamides having an ammonium group.

The saponification degree of the polyvinyl alcohol resin is usually about 85 to 100 mol%, preferably 98 mol% or more. The polyvinyl alcohol resin may be modified, and for example, polyvinyl formal or polyvinyl acetal modified with aldehydes can also be used. The degree of polymerization of the polyvinyl alcohol resin is usually about 1,000 to 10,000, preferably 1,500 to 5,000.

A film made of such a polyvinyl alcohol resin is used as a raw film of a polarizing film. The method of forming a polyvinyl alcohol resin into a film is not particularly limited, and any known method can be used to form the film. The thickness of the polyvinyl alcohol base film can be, for example, about 10 to 150 μm.

Uniaxial stretching of the polyvinyl alcohol resin film can be performed before, simultaneously with, or after dyeing with a dichroic dye. When uniaxial stretching is performed after dyeing, this uniaxial stretching may be performed before or during the boric acid treatment. Moreover, it is also possible to perform uniaxial stretching in these plural steps. In the uniaxial stretching, it may be uniaxially stretched between rolls having different circumferential speeds, or it may be uniaxially stretched using hot rolls. Further, the uniaxial stretching may be dry stretching in which the film is stretched in the atmosphere, or wet stretching in which the polyvinyl alcohol resin film is stretched in a swollen state using a solvent. The stretching ratio is usually about 3 to 8 times.

Staining of a polyvinyl alcohol resin film with a dichroic dye is carried out, for example, by immersing the polyvinyl alcohol resin film in an aqueous solution containing the dichroic dye.

Specifically, iodine or a dichroic organic dye is used as the dichroic dye. As a dichroic organic dye, C.I. I. Examples include dichroic direct dyes made of disazo compounds such as DIRECT RED 39, and dichroic direct dyes made of compounds such as trisazo and tetrakisazo. It is preferable that the polyvinyl alcohol resin film is immersed in water before being dyed.

When using iodine as a dichroic dye, a method is usually employed in which a polyvinyl alcohol resin film is immersed in an aqueous solution containing iodine and potassium iodide for dyeing. The content of iodine in this aqueous solution is usually about 0.01 to 1 part by mass per 100 parts by mass of water. Further, the content of potassium iodide is usually about 0.5 to 20 parts by mass per 100 parts by mass of water. The temperature of the aqueous solution used for dyeing is usually about 20 to 40°C. The immersion time (staining time) in this aqueous solution is usually about 20 to 1,800 seconds.

On the other hand, when using a dichroic organic dye as the dichroic dye, a method of dyeing by immersing a polyvinyl alcohol resin film in an aqueous solution containing a water-soluble dichroic dye is usually employed. The content of the dichroic organic dye in this aqueous solution is usually about 1 x 10 ^-4 to 10 parts by weight, preferably 1 x 10 -3 to 1 part by weight, and more preferably about 1 x 10 ^-4 to 1 part by weight, per 100 parts by weight of water. is 1×10 ⁻³ to 1×10 ⁻² parts by mass. This aqueous solution may contain an inorganic salt such as sodium sulfate as a dyeing aid. The temperature of the dichroic dye aqueous solution used for dyeing is usually about 20 to 80°C. The immersion time (staining time) in this aqueous solution is usually about 10 to 1,800 seconds.

The boric acid treatment after dyeing with a dichroic dye can usually be carried out by immersing the dyed polyvinyl alcohol resin film in an aqueous boric acid solution. The content of boric acid in this boric acid aqueous solution is usually about 2 to 15 parts by weight, preferably 5 to 12 parts by weight, per 100 parts by weight of water. When iodine is used as the dichroic dye, the boric acid aqueous solution preferably contains potassium iodide, and the content of potassium iodide in this case is usually 0.1 to 100 parts by mass of water. The amount is about 15 parts by mass, preferably 5 to 12 parts by mass. The immersion time in the boric acid aqueous solution is usually about 60 to 1,200 seconds, preferably 150 to 600 seconds, and more preferably 200 to 400 seconds. The temperature of the boric acid treatment is usually 50°C or higher, preferably 50 to 85°C, more preferably 60 to 80°C.

The polyvinyl alcohol resin film treated with boric acid is usually washed with water. The water washing treatment can be performed, for example, by immersing a boric acid-treated polyvinyl alcohol resin film in water. The temperature of water in the washing process is usually about 5 to 40°C. The immersion time is usually about 1 to 120 seconds.

After washing with water, a drying process is performed to obtain a polarizer. The drying process can be performed using, for example, a hot air dryer or a far-infrared heater. The temperature of the drying treatment is usually about 30 to 100°C, preferably 50 to 80°C. The drying time is usually about 60 to 600 seconds, preferably 120 to 600 seconds. The drying process reduces the moisture content of the polarizer to a practical level. Its moisture content is usually about 5 to 20% by weight, preferably 8 to 15% by weight. When the moisture content is within the above range, a polarizer having appropriate flexibility and excellent thermal stability can be obtained.

The thickness of the polarizer obtained by subjecting the polyvinyl alcohol resin film to uniaxial stretching, dyeing with a dichroic dye, boric acid treatment, washing with water, and drying is preferably 5 to 40 μm.

Films coated with dyes having absorption anisotropy include films obtained by coating compositions containing dichroic dyes having liquid crystallinity or compositions containing dichroic dyes and polymerizable liquid crystals. Can be mentioned. The film preferably has a protective film on one or both sides thereof. The protective film may be the same as the resin film exemplified above as a base material that can be used for producing a horizontally aligned liquid crystal cured film.

It is preferable for a film coated with a dye having absorption anisotropy to be thin, but if it is too thin, the strength tends to decrease and processability tends to be poor. The thickness of the film is usually 20 μm or less, preferably 5 μm or less, and more preferably 0.5 to 3 μm.

Specific examples of the film coated with the dye having absorption anisotropy include the films described in JP-A No. 2012-33249 and the like.

A polarizing film is obtained by laminating a transparent protective film on at least one surface of the thus obtained polarizer via an adhesive. As the transparent protective film, a transparent film similar to the resin film exemplified above as a base material that can be used for manufacturing an optically anisotropic film can be preferably used.

The elliptically polarizing plate of the present invention includes the optically anisotropic film of the present invention and the polarizing film. For example, the optically anisotropic film of the present invention and the polarizing film are combined with an adhesive layer or the like. The elliptically polarizing plate of the present invention can be obtained by laminating the elliptically polarizing plate through the laminate. Moreover, the elliptically polarizing plate of the present invention can be obtained by laminating a polarizing film with a laminate obtained by removing the base material from the optical film of the present invention.

In one embodiment of the present invention, when the optically anisotropic film of the present invention and a polarizing film are laminated, the angle between the slow axis (optical axis) of the optically anisotropic film and the absorption axis of the polarizing film is 45 It is preferable to stack the layers so that the angle is ±5°.

The elliptically polarizing plate of the present invention may have a configuration similar to that of a conventional general elliptically polarizing plate, or a polarizing film and a retardation film. Such structures include, for example, adhesive layers (sheets) used to bond elliptically polarizing plates to display elements such as organic EL, and adhesive layers used to protect the surfaces of polarizing films and retardation films from scratches and dirt. Protective films and the like can be mentioned.

The elliptically polarizing plate of the present invention can be used in various display devices. A display device is a device having a display mechanism, and includes a light emitting element or a light emitting device as a light source. Display devices include liquid crystal displays, organic electroluminescent (EL) display devices, inorganic electroluminescent (EL) display devices, touch panel display devices, electron emission display devices (e.g. field emission display (FED), surface field emission display device). (SED)), electronic paper (display devices using electronic ink or electrophoretic elements, plasma display devices, projection display devices (e.g., grating light valve (GLV) display devices, display devices with digital micromirror devices (DMD)) ) and piezoelectric ceramic displays.Liquid crystal display devices include transmissive liquid crystal display devices, transflective liquid crystal display devices, reflective liquid crystal display devices, direct-view liquid crystal display devices, and projection type liquid crystal display devices. These display devices may be display devices that display two-dimensional images or stereoscopic display devices that display three-dimensional images.In particular, the elliptically polarizing plate of the present invention It can be suitably used for display devices.

In one embodiment of the present invention, an organic EL display device is configured from a laminate including the elliptically polarizing plate of the present invention and a front plate or a touch sensor panel, and an organic EL display panel. Therefore, the present invention also covers a laminate including the elliptically polarizing plate of the present invention and a front plate, a laminate including the elliptically polarizing plate of the present invention and a touch sensor panel, and an organic EL display device including the laminate. shall be.

The front plate constituting the laminate including the elliptically polarizing plate and the front plate of the present invention is disposed on the viewing side of the organic EL display device, and protects other components constituting the display device from external shocks, temperature, humidity, etc. plays the role of protecting against environmental changes. The front plate is preferably made of an inorganic material such as glass or tempered glass, or a polymer film. In particular, a polymer film having flexible properties is suitable as a front plate constituting a foldable laminate for a flexible display device.

The polymer film is usually a transparent polymer film, and its visible light transmittance is preferably 70% or more, more preferably 80% or more. Specifically, polyamide films, polyamide-imide films, polyimide films, polyester films, olefin films, acrylic films, cellulose films, etc., which have excellent transparency and heat resistance, can be used.

It is also preferable to disperse inorganic particles such as silica, organic fine particles, rubber particles, etc. in the polymer film. In addition, colorants such as pigments and dyes, optical brighteners, dispersants, plasticizers, heat stabilizers, light stabilizers, infrared absorbers, ultraviolet absorbers, antistatic agents, antioxidants, lubricants, solvents, etc. may be blended.

The front plate may have functions such as scratch prevention, anti-reflection, antifouling, electromagnetic wave shielding, near-infrared shielding, color adjustment, and glass shatter prevention. In order to provide such functions, at least one layer (for example, a hard coat layer) having these functions may be laminated on at least one surface of the front plate.

A laminate including the elliptically polarizing plate of the present invention and a touch sensor panel includes a touch sensor in addition to the elliptically polarizing plate of the present invention and a front plate. As the front plate, a front plate similar to that exemplified above in the laminate including the elliptically polarizing plate and the front plate of the present invention can be used.

A touch sensor is used as an input means. There are various types of touch sensors, such as a resistive film type, a surface acoustic wave type, an infrared type, an electromagnetic induction type, and a capacitance type, and any type may be used. A touch sensor includes a substrate having flexible characteristics; a sensing pattern formed on an active area of the substrate where a user's touch is sensed; and a sensing pattern formed on a non-active area located at the outer part of the active area, and the sensing pattern formed on the active area. Each sensing line may be included for connection to an external driving circuit via the pattern and pad portion.

In the laminate of the present invention, the elliptically polarizing plate, front plate, and/or touch sensor of the present invention may be laminated by laminating each member via an adhesive layer as necessary. When the laminate of the present invention includes an adhesive layer, in order to suppress reflection and scattering of light at the interface between the front plate and the elliptically polarizing plate and improve visibility, the refractive index of the adhesive layer is set to the refractive index of the front plate. It is preferable to select an adhesive that is close to the optical transparency and is optically clear.

Examples of adhesives include water-based adhesives, organic solvent-based adhesives, solvent-free adhesives, solid adhesives, solvent volatilization adhesives, moisture-curing adhesives, heat-curing adhesives, anaerobic-curing adhesives, and active energy rays. Those widely used in the field, such as curable adhesives, curing agent mixed adhesives, hot-melt adhesives, pressure-sensitive adhesives (adhesives), and rewetting adhesives, can be used.

The stacking order of the elliptically polarizing plate, the front plate, and the touch sensor of the present invention in the laminate of the present invention is not particularly limited, and for example, from the viewing side,
Front plate/adhesive layer/elliptically polarizing plate/adhesive layer/touch sensor Front plate/adhesive layer/touch sensor/adhesive layer/elliptically polarizing plate, etc. may be used.
In the above laminate, the organic EL display device of the present invention is manufactured by bonding the outermost layer of the laminate opposite to the front plate (i.e., the touch sensor or the elliptically polarizing plate) and the organic EL display panel. be able to. The organic EL display device of the present invention has good performance over a long period of time because it includes the optically anisotropic film of the present invention that is unlikely to change its retardation value over time and has excellent front reflection hue in a wide wavelength range of visible light. It is possible to exhibit excellent image display characteristics.

Hereinafter, the present invention will be explained in more detail with reference to Examples. In addition, "%" and "parts" in the examples mean % by mass and parts by mass, respectively, unless otherwise specified.

1. Example 1
(1) Preparation of polymerizable liquid crystal composition Polymerizable liquid crystal compound (A-1) (molecular weight: 1156), polymerizable liquid crystal compound (B-1) (molecular weight: 664) and polymerizable liquid crystal compound ( C-1) (molecular weight: 1083) was prepared.

重合性液晶化合物（Ａ－１）は特開２０１１－２０７７６５号公報に記載の方法で合成した。 Polymerizable liquid crystal compound (A-1):

Polymerizable liquid crystal compound (A-1) was synthesized by the method described in JP-A-2011-207765.

重合性化合物（Ｂ－１）は特開２０１０－２４４３８号公報に記載の方法で合成した。 Polymerizable liquid crystal compound (B-1):

Polymerizable compound (B-1) was synthesized by the method described in JP-A-2010-24438.

重合性化合物（Ｃ－１）は特開２０１１－２０７７６５号公報に記載の方法で合成した。 Polymerizable liquid crystal compound (C-1):

Polymerizable compound (C-1) was synthesized by the method described in JP-A-2011-207765.

83 parts by mass of polymerizable liquid crystal compound (A-1), 3 parts by mass of polymerizable liquid crystal compound (B-1), and 14 parts by mass of polymerizable liquid crystal compound (C-1) were mixed, and liquid crystal mixture (1) ( A total of 100 parts by mass) was obtained.

With reference to the patent document (JP 2017-179367), the liquid crystal mixture (1), a polymerization initiator, a leveling agent, a polymerization inhibitor, and a solvent were mixed according to the composition shown in Table 1, and a polymerizable liquid crystal composition was prepared. Product (1) was prepared. Note that the amounts of the polymerization initiator, leveling agent, and polymerization inhibitor shown in Table 1 are the amounts added to 100 parts by mass of the liquid crystal mixture (1). Further, the amount of the solvent was set so that the mass % of the liquid crystal mixture (1) was 10 mass % based on the total amount of the polymerizable liquid crystal composition (1). Specifically, the solvent was added so that 100 parts by mass of the liquid crystal mixture (1) was contained in 1000 parts by mass of the polymerizable liquid crystal composition (1).

Polymerization initiator: 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butan-1-one (Irgacure (registered trademark) 369; manufactured by BASF Japan)
Leveling agent: polyacrylate compound (BYK-361N; manufactured by BYK Chemie Japan)
Polymerization inhibitor: dibutylhydroxytoluene (BHT; manufactured by Wako Pure Chemical Industries, Ltd.)
Solvent: N-methylpyrrolidone (NMP; manufactured by Kanto Kagaku Co., Ltd.)

(2) Preparation of a composition for forming a photo-alignment film Mix 5 parts by mass of a photo-alignable material with the following structure and 95 parts by mass of cyclopentanone (solvent), and stir the resulting mixture at 80°C for 1 hour. A composition (1) for forming a photo-alignment film was obtained. The photo-alignable material represented by the following formula was synthesized by the method described in JP-A-2013-33248.
photo-alignable material

(3) Production of optical film An optical film was produced as follows. Cycloolefin polymer film (COP) (ZF-14, manufactured by Zeon Corporation, thickness 23 μm) was processed using a corona treatment device (AGF-B10, manufactured by Kasuga Denki Co., Ltd.) at an output of 0.3 kW and a processing speed of 3 m/min. It was treated once under the following conditions. The photo-alignment film forming composition (1) was applied with a bar coater to the corona-treated surface, dried at 80°C for 1 minute, and then heated using a polarized UV irradiation device (SPOT CURE SP-7; manufactured by Ushio Inc.) ) with an integrated light intensity of 100 mJ/cm ² to obtain a substrate with an alignment film. The thickness of the obtained alignment film was measured using a laser microscope (LEXT, manufactured by Olympus Corporation) and was found to be 100 nm.

Subsequently, the prepared polymerizable liquid crystal composition (1) was passed through a PTFE membrane filter (manufactured by Advantech Toyo Co., Ltd., product number: T300A025A) with a pore size of 0.2 μm in an environment of a temperature of 25 ° C. and a humidity of 30% RH. The polymerizable liquid crystal composition (1) was applied using a bar coater onto a substrate with an alignment film kept at 25°C. The coating was dried at 120°C for 1 minute. Using a high-pressure mercury lamp (Unicure VB-15201BY-A, manufactured by Ushio Inc.), the dried coating film was irradiated with ultraviolet rays to polymerize the polymerizable liquid crystal compound to produce an optical film. The integrated light amount of the irradiated ultraviolet light at a wavelength of 365 nm was 1000 mJ/cm ² . Note that the ultraviolet irradiation was performed under a nitrogen atmosphere. The optical film is formed by laminating a base material, an alignment film, and an optically anisotropic film in this order. The thickness of the obtained optically anisotropic film was measured using a laser microscope (LEXT, manufactured by Olympus Corporation) and was found to be 2 μm.

Next, the obtained optical film was immersed in cyclohexanone for 60 seconds in an environment at a temperature of 25° C. (solvent immersion step). After the optical film was taken out, the solvent was dried by allowing it to stand overnight in an environment at a temperature of 25°C.

(4) Evaluation of physical properties/characteristics of optical film After drying the solvent, three-dimensional refractive index, retardation value, and change in retardation value (ΔRe) in durability evaluation were measured according to the following evaluation method. The evaluation results are shown in Table 2.

(i) Calculation of three-dimensional refractive index and retardation value of optically anisotropic film. After the optically anisotropic film surface (the surface opposite to the base material) of the optical film was laminated, the base material was peeled off. Thereafter, a 23 μm cycloolefin polymer film (COP) (ZF-14, manufactured by Nippon Zeon Co., Ltd., thickness 23 μm) was further laminated via the same pressure-sensitive adhesive to prepare a sample for evaluation of the retardation value. Note that the COP used here is an optically isotropic film with a retardation value of 1 nm or less at a wavelength of 550 nm, and it was confirmed that the evaluation of the retardation value was not affected.

Regarding the sample for evaluating the above-mentioned phase difference value, using a measuring device ("KOBRA-WPR" manufactured by Oji Scientific Instruments Co., Ltd.), the in-plane phase difference of the optically anisotropic film was measured by changing the incident angle of light to the sample. and the phase difference value when tilted by 40 degrees around the fast axis. The average refractive index at each wavelength was measured using an ellipsometer M-220 manufactured by JASCO Corporation. Further, the film thickness was measured using an Optical NanoGauge film thickness meter C12562-01 manufactured by Hamamatsu Photonics Co., Ltd.

Based on the above-mentioned in-plane retardation value, retardation value when tilted by 40 degrees around the fast axis, average refractive index, and film thickness values, technical data published by Oji Scientific Instruments Co., Ltd. (http:/ /www.oji-keisoku.co.jp/products/kobra/reference.html), the three-dimensional refractive index was calculated. From the obtained three-dimensional refractive index, the optical properties of the optically anisotropic film were calculated according to the following formula.

(ii) Measurement of change in phase difference value (ΔRe) in durability test The above-mentioned sample for evaluation of phase difference value was placed in an air oven (PH-201 manufactured by Espec) controlled at 105°C for 30 minutes as a durability test. Thereafter, it was taken out and allowed to stand in an environment of 25° C. and 55% RH for more than 6 hours. Thereafter, the in-plane retardation value was measured again using the above-mentioned KOBRA-WPR.
From the phase difference values before and after the durability test, the amount of change in the phase difference value (|ΔRe|) was calculated based on the following formula.

2. Example 2
An optical film was produced and evaluated in the same manner as in Example 1, except that the immersion time in cyclohexanone was 240 seconds. The evaluation results are shown in Table 2.

3. Example 3
An optical film was produced and evaluated in the same manner as in Example 1, except that the immersion time in cyclohexanone was 420 seconds. The evaluation results are shown in Table 2.

4. Comparative example 1
An optical film was produced and evaluated in the same manner as in Example 1, except that the solvent dipping step was not performed after UV irradiation. The evaluation results are shown in Table 2.

In the optical film produced in the example, the amount of change in retardation value (|ΔReA|) was small, and it was confirmed that the optical film had excellent reliability during long-term use.

Claims (10)

An optically anisotropic film made of a cured product of a polymerizable liquid crystal composition, the film having the formula (1):
1.002≦nyA(450)/nzA(450)≦1.010 (1)
[In formula (1), nyA (450) is the wavelength λ = 450 nm in the direction y perpendicular to the direction x (slow axis direction) showing the highest in-plane principal refractive index in the same plane. nzA (450) represents the refractive index at wavelength λ = 450 nm in the film thickness direction of the optically anisotropic film ],
Formula (2):
ReA(450)/ReA(550)<1.00 (2)
[In formula (2), ReA (λ) represents the in-plane retardation value of the optically anisotropic film at the wavelength λ nm, and ReA (λ) = (nxA (λ) - nyA (λ)) x dA [ In the formula, nxA(λ) represents the refractive index at wavelength λnm in the plane of the optically anisotropic film, and nyA(λ) represents the refractive index at wavelength λnm in the same plane as nxA in the direction orthogonal to the direction of nxA. represents the refractive index, and dA represents the thickness of the optically anisotropic film] , and
Formula (4):
120nm≦ReA(550)≦170nm (4)
[In formula (4), ReA (550) represents the in-plane retardation value of the optically anisotropic film at a wavelength of 550 nm]
An optically anisotropic film that satisfies the following requirements. Formula (3):
1.002≦nyA(550)/nzA(550)≦1.010 (3)
[In formula (3), nyA (550) is the wavelength λ = 550 nm in the direction y perpendicular to the direction x (slow axis direction) showing the highest refractive index among the in-plane principal refractive indexes in the same plane. nzA (550) represents the refractive index at wavelength λ = 550 nm in the film thickness direction of the optically anisotropic film]
The optically anisotropic film according to claim 1, which satisfies the following. The optically anisotropic film according to claim 1 or 2, which is a cured product of a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound having at least one polymerizable group. A cured product of a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound having at least one polymerizable group, wherein the polymerizable liquid crystal compound is cured in a state in which the polymerizable liquid crystal compound is oriented horizontally with respect to the plane of the optically anisotropic film. The optically anisotropic film according to any one of claims 1 to 3, comprising: An optical film comprising the optically anisotropic film according to any one of claims 1 to 4 . An elliptically polarizing plate comprising the optically anisotropic film according to any one of claims 1 to 4 and a polarizing film. The elliptically polarizing plate according to claim 6 , wherein the angle between the slow axis of the optically anisotropic film and the absorption axis of the polarizing film is 45±5°. A laminate comprising the elliptically polarizing plate according to claim 6 or 7 and a front plate. A laminate comprising the elliptically polarizing plate according to claim 6 or 7 and a touch sensor panel. An organic EL display device comprising the laminate according to claim 8 or 9 .