JP2021081651A - Optical anisotropic film - Google Patents

Abstract

To provide an optical anisotropic film that hardly causes changes in a retardation value with time and can exhibit excellent optical characteristics for a long period of time when assembled in an image display device, and an optical film, an elliptical polarizing plate, a laminate and an organic EL display device including the optical anisotropic film.SOLUTION: The optical anisotropic film satisfies formula (1): 1.002≤nyA(450)/nzA(450)≤1.010 and formula (2): ReA(450)/ReA(550)<1.00. In formula (1), nyA(450) represents a refractive index at a wavelength λ of 450 nm in a direction y orthogonal to a direction x (slow axis direction) within the same plane, the direction x indicating the highest refractive index among in-plane principal refractive indices; and nzA(450) represents a refractive index at a wavelength λ of 450 nm in a thickness direction of the optical anisotropic film. In formula (2), ReA(λ) represents an in-plane retardation value of the optical anisotropic film at a wavelength λ nm and is defined by ReA(λ)=(nxA(λ)-nyA(λ))×dA, where nxA(λ) represents a refractive index at a wavelength λ nm within the plane of the optical anisotropic film, nyA(λ) represents a refractive index at a wavelength λ nm in a direction orthogonal to the direction of nxA and within the same plane as nxA, and dA represents the film thickness of the optical anisotropic film.SELECTED DRAWING: None

Description

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

The elliptical polarizing plate is an optical member in which a polarizing film and a retardation film are laminated. For example, in a device for displaying an image in a flat state such as an organic EL image display device, light reflection by electrodes constituting the device is used. It is used to prevent. As the retardation film constituting this elliptical polarizing plate, a so-called λ / 4 plate is generally used.

As the retardation film constituting the elliptical polarizing plate, a film exhibiting anti-wavelength dispersibility is preferable in that uniform retardation performance can be easily exhibited in 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 dispersibility is polymerized in a state of being oriented horizontally with respect to the plane of the retardation film and cured. A retardation film composed of a horizontally oriented liquid crystal cured film is known.

Japanese Unexamined Patent Publication No. 2015-163935

However, in the conventional retardation film exhibiting reverse wavelength dispersibility, the retardation value of the retardation film may change with the passage of time. The retardation value of the retardation film greatly affects the reflected hue of the elliptical polarizing plate when the retardation film is incorporated into the elliptical polarizing plate. Therefore, when such a change in the retardation value with time occurs, it becomes difficult to obtain a desired reflected hue in an image display device incorporating an elliptical polarizing plate including the retardation film, and optical characteristics over time become difficult. It contributes to the deterioration of the image quality and the defect in the appearance quality.

INDUSTRIAL APPLICABILITY The present invention includes an optically anisotropic film that is unlikely to change in phase difference value over time and can exhibit excellent optical characteristics for a long period of time when incorporated into an image display device, an optical film containing the same, and elliptically polarized light. It is an object of the present invention to provide a plate, a laminate, and an organic EL display device.

The present inventors have completed the present invention as a result of diligent studies to solve the above problems. That is, the present invention includes the following aspects.
[1] Equation (1):
1.002 ≤ meow (450) / nzA (450) ≤ 1.010 (1)
[In the formula (1), nyA (450) has a wavelength λ = 450 nm in the direction y orthogonal to the direction x (slow-phase axis direction) showing the highest refractive index among the in-plane main refractive indexes in the same plane. NzA (450) represents the refractive index at the wavelength λ = 450 nm in the film thickness direction of the optically anisotropic film.]
And equation (2):
ReA (450) / ReA (550) <1.00 (2)
[In equation (2), ReA (λ) represents the in-plane retardation value of the optically anisotropic film at a wavelength of λ nm, and ReA (λ) = (nxA (λ) −nyA (λ)) × dA [ In the equation, nxA (λ) represents the refractive index at a wavelength of λ nm in the plane of the optically anisotropic film, and nyA (λ) is at a wavelength of λ nm in the same plane as nxA and perpendicular to the direction of nxA. Represents the refractive index, dA indicates the film thickness of the optically anisotropic film]]
An optically anisotropic film that meets the requirements.
[2] Equation (3):
1.002 ≤ meow (550) / nzA (550) ≤ 1.010 (3)
[In the formula (3), nyA (550) has a wavelength λ = 550 nm in the direction y orthogonal to the direction x (slow phase axis direction) showing the highest refractive index among the in-plane main refractive indexes in the same plane. NzA (550) represents the refractive index at the wavelength λ = 550 nm in the film thickness direction of the optically anisotropic film.]
The optically anisotropic film according to the above [1].
[3] The optically anisotropic film according to the above [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.
[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 horizontally with respect to an optically anisotropic film plane. The optically anisotropic film according to any one of [1] to [3] above, which is cured with.
[5] Equation (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 the above [1] to [4], which satisfies the above conditions.
[6] An optical film containing the optically anisotropic film according to any one of the above [1] to [5].
[7] An elliptical polarizing plate including the optically anisotropic film and the polarizing film according to any one of the above [1] to [5].
[8] The elliptical polarizing plate according to the above [7], wherein the angle formed by the slow axis of the optically anisotropic film and the absorption axis of the polarizing film is 45 ± 5 °.
[9] A laminate including the elliptical polarizing plate and the front plate according to the above [7] or [8].
[10] A laminate including the elliptical polarizing plate according to the above [7] or [8] and a touch sensor panel.
[11] An organic EL display device including the laminate according to the above [9] or [10].

According to the present invention, an optically anisotropic film that is unlikely to change in phase difference value with time and can exhibit excellent optical characteristics for a long period of time when incorporated in an image display device, and an optical film containing the same. An elliptical polarizing plate, a laminate, and an organic EL display device can be provided.

The optically anisotropic film of the present invention satisfies the formula (1).
1.002 ≤ meow (450) / nzA (450) ≤ 1.010 (1)
In the formula (1), nyA (450) has a wavelength λ = 450 nm in the direction y orthogonal to the direction x (slow-phase axis direction) showing the highest refractive index among the in-plane main refractive indexes in the same plane. NzA (450) represents the refractive index of the optically anisotropic film at the wavelength λ = 450 nm in the film thickness direction.
By satisfying the formula (1), it is possible to obtain an optically anisotropic film capable of maintaining the initial optical characteristics for a long period of time without causing a change in the retardation value with time.

The optically anisotropic film of the present invention satisfies the formula (2) in addition to the formula (1).
ReA (450) / ReA (550) <1.00 (2)
In the formula (2), ReA (λ) represents an in-plane retardation value of the optically anisotropic film at a wavelength of λ nm, and ReA (λ) = (nxA (λ) −nyA (λ)) × dA. In the above formula, nxA (λ) represents the refractive index at the wavelength λ nm in the optically anisotropic film plane, and nyA (λ) is the wavelength λ nm in the same plane as nxA and in the direction orthogonal to the direction of nxA. Represents the refractive index of, and dA indicates the film thickness of the optically anisotropic film.
By satisfying the equation (2) showing so-called inverse wavelength dispersibility in addition to the equation (1), uniform phase difference performance can be exhibited in a wide wavelength range of visible light, so that excellent optical characteristics over a long period of time / It is an optically anisotropic film that can be suitably used as a constituent member of an image display device that maintains display characteristics. ReA (450) / ReA (550) is preferably 0.70 or more, more preferably 0.70 or more, because the inverse wavelength dispersibility is improved and the effect of improving the reflected hue in the front direction of the optically anisotropic film can be further enhanced. Is 0.78 or more, preferably 0.95 or less, more preferably 0.92 or less, still more preferably 0.90 or less, particularly preferably 0.87 or less, and 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 equation 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 of the optically anisotropic film at nm), the three-dimensional refractive index and the film thickness dA may be adjusted.

The optically anisotropic film of the present invention preferably further satisfies the formula (3).
1.002 ≤ meow (550) / nzA (550) ≤ 1.010 (3)
In the formula (3), nyA (550) has a wavelength λ = 550 nm in the direction y orthogonal to the direction x (slow phase axis direction) showing the highest refractive index among the in-plane main refractive indexes in the same plane. NzA (550) represents the refractive index of the optically anisotropic film at the wavelength λ = 550 nm in the film thickness direction.
By satisfying the equation (3), the effect of suppressing the change in the retardation value with time tends to be further improved, and the optically anisotropic film can exhibit the initial optical characteristics for a long period of time.

Further, the optically anisotropic film of the present invention preferably satisfies the formula (4).
120nm ≤ ReA (550) ≤ 170nm (4)
In the formula (4), ReA (550) represents the in-plane retardation value of the optically anisotropic film at the wavelength λ = 550 nm.
When the in-plane retardation value ReA (550) of the optically anisotropic film is within the range of the formula (4), the effect of improving the specular hue when the optically anisotropic film is applied to the display device (coloring). The effect of suppressing) becomes remarkable. A more preferable range of the in-plane retardation value is 130 nm ≦ ReA (550) ≦ 150 nm. Hereinafter, the effect relating to "improvement of specular hue" in the present specification means an effect of improving specular hue when the elliptical polarizing plate including the optically anisotropic film of the present invention is applied to a display device.

The optically anisotropic film of the present invention preferably satisfies the formula (5).
nxA (450)> nyA (450)> nzA (450) (5)
In formula (5), nxA (450), nyA (450) and nzA (450) have the same meanings as described above.
When the formula (5) is satisfied, the wavelength dispersibility of the optically anisotropic film tends to be further improved [that is, the values of ReA (450) / ReA (550) become smaller], so that the optically anisotropic film tends to be smaller. Better specular hues can be obtained when the film is applied to an image display device.

Further, the optically anisotropic film of the present invention preferably satisfies the formula (6).
nxA (550)> nyA (550)> nzA (550) (6)
In formula (6), nxA (550), nyA (550) and nzA (550) have the same meanings as described above.
When the formula (6) is satisfied, the wavelength dispersibility of the optically anisotropic film tends to be further improved. Therefore, when the optically anisotropic film is applied to an image display device, a better specular hue is obtained. be able to. In particular, by satisfying the above formula (6) together with the formula (5), the effect of improving the specular reflection hue when the optically anisotropic film is applied to an image display device can be remarkable.

The optically anisotropic film of the present invention may be formed so as to satisfy the optical characteristics represented by the formulas (1) and (2). For example, a stretched film obtained by stretching a base material formed of a translucent resin such as polyethylene terephthalate, poly (meth) acrylic acid ester, cellulose ester, cyclic olefin resin, polycarbonate, polyamide, polyimide, and polyamideimide. Alternatively, it may be a cured product (cured film) of a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound having at least one polymerizable group. Among them, an optically anisotropic film having a retardation performance 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. A cured product obtained by curing the polymerizable liquid crystal compound in a state of being horizontally oriented with respect to an optically anisotropic film plane (hereinafter, also referred to as "horizontally oriented liquid crystal cured film") is more preferable. ..

When the optically anisotropic film of the present invention is a horizontally oriented liquid crystal cured film, the in-plane retardation value at short wavelengths is smaller than the in-plane retardation value at long wavelengths. It can be formed from a polymerizable liquid crystal compound exhibiting so-called inverse wavelength dispersibility. A polymerizable liquid crystal compound exhibiting such inverse wavelength dispersibility usually has a T-shaped structure in which constituent molecules are arranged in a major axis direction that is the main chain of the compound and a direction that intersects the major axis direction. (Hereinafter, the molecular structure portion constituting the long axis direction of the polymerizable liquid crystal compound is also referred to as a "mesogen part", and the molecular structure part forming a direction intersecting the long axis direction is also referred to as a "core part". ). Conventionally, in a horizontally oriented liquid crystal cured film exhibiting reverse wavelength dispersibility, the refractive indexes 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). It becomes a relationship of plate). In the 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, and the direction (orientation) of the constituent molecules is not controlled in the plane of the liquid crystal cured film. The refractive index nyA in the direction orthogonal 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 magnitude (nyA≈nzA).

On the other hand, the present invention controls 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, and is the most in-plane main refractive index. Refractive index nyA in the direction orthogonal to the direction x (slow phase axis direction) showing high refractive index in the same plane, and refractive index nzA in the film thickness direction (vertical direction) with respect to the plane of the optically anisotropic film. The ratio with [nyA (λ) / nzA (λ)] is set to a specific range. That is, the optically anisotropic film of the present invention has the formula (1) :.
1.002 ≤ meow (450) / nzA (450) ≤ 1.010 (1)
Meet.
In the present invention, the principle of the effect that the optically anisotropic film can suppress the change of the retardation value with time by satisfying the equation (1) is not necessarily clear, but is presumed as follows. When the ratio of nyA (λ) and nzA (λ) is within the above-mentioned specific range, the optically anisotropic film has the mesogen portion of the polymerizable liquid crystal compound in the x direction and the core portion on the same plane in the film plane. A cured liquid crystal cured film is obtained by polymerizing in a state of being selectively oriented in the y direction orthogonal to the x direction. Such a liquid crystal cured film causes stacking with a certain direction between the core portions of each polymerizable liquid crystal compound constituting the liquid crystal cured film in the initial state after film formation, and is structurally highly stable. Has. Therefore, the directionality of the constituent molecules of the polymerizable liquid crystal compound so as to satisfy the formula (1) as compared with the conventional positive A plate in which the directionality of the isotropically distributed core portion tends to change with time (1). The optically anisotropic film of the present invention in which the orientation (orientation) is controlled is unlikely to cause a change in the orientation state of the polymerizable liquid crystal compound, and can suppress a change in the retardation value over time due to the change in the orientation state. It will be possible.

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

The 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 the polymerization reaction by a reactive species generated from the photopolymerization initiator, for example, an active radical or an acid, as a polymerizable group. It is preferable to have. Examples of the photopolymerizable group include a vinyl group, a vinyloxy group, a 1-chlorovinyl group, an isopropenyl group, a 4-vinylphenyl group, an acryloyloxy group, a methacryloyloxy group, an oxylanyl group, an oxetanyl group and the like. Of these, an acryloyloxy group, a methacryloyloxy group, a vinyloxy group, an oxylanyl group and an oxetanyl group are preferable, and an acryloyloxy group is more preferable.

The liquid crystal property 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 in that precise film thickness control is possible. 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 compound can be used alone or in combination of two or more.

Examples of the polymerizable liquid crystal compound include a polymerizable liquid crystal compound exhibiting positive wavelength dispersibility and a polymerizable liquid crystal compound exhibiting reverse wavelength dispersibility, and the obtained optically anisotropic film has optical characteristics satisfying the formula (2). As long as it has (that is, exhibits inverse wavelength dispersibility), only one of the polymerizable liquid crystal compounds can be used, or a plurality of types of the polymerizable liquid crystal compounds of both types can be mixed and used. it can. In the image display device incorporating the obtained optically anisotropic film, the front reflection hue can be easily improved, and the durability improving effect in the present invention can be remarkably obtained. Therefore, the polymerizable liquid crystal compound is individually oriented in a specific direction. It is preferable that the polymer obtained by polymerizing in the state contains a polymerizable liquid crystal compound exhibiting inverse wavelength dispersibility. As the polymerizable liquid crystal compound, only one kind may be used, or two or more kinds 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 the direction [intersection direction (b)] intersecting with respect to the major axis direction (a).
(D) A polymerizable liquid crystal compound defined by the following formula (i), where the total number of π electrons existing in the major axis direction (a) is N (πa) and the total molecular weight existing in the major axis direction is N (Aa). Π electron density in the major axis direction (a) of
D (πa) = N (πa) / N (Aa) (i)
The polymerizable liquid crystal compound defined by the following formula (ii), where the total number of π electrons existing in the crossing direction (b) is N (πb) and the total molecular weight existing in the crossing direction (b) is N (Ab). Π electron density in the crossing direction (b) of
D (πb) = N (πb) / N (Ab) (ii)
And, the formula (iii)
0 ≦ [D (πa) / D (πb)] <1 (iii)
[That is, the π-electron density in the crossing 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 a major axis and π electrons in the crossing direction with respect to the major axis tends to have a T-shaped structure in general.

In the above features (A) to (D), the major axis direction (a) and the number of π electrons N are defined as follows.
The major axis direction (a) is, for example, the rod-shaped major axis direction of a compound having a rod-shaped structure.
The number of π electrons N (πa) existing in the major axis direction (a) does not include π electrons that disappear due to the polymerization reaction.
The number of π electrons N (πa) existing in the major axis direction (a) is the total number of π electrons on the major axis and π electrons conjugated thereto, for example, existing in the major axis direction (a). The number of π electrons present in the ring that satisfies Hückel's law is included.
-The number of π electrons N (πb) existing in the crossing direction (b) does not include π electrons that disappear due to the polymerization reaction.
The polymerizable liquid crystal compound satisfying the above has a mesogen structure in the major axis direction. The liquid crystal phase (nematic phase, smectic phase) is expressed by this mesogen structure.

A nematic phase or a smectic phase is formed by applying a polymerizable liquid crystal compound satisfying the above (A) to (D) on a film (layer) forming a liquid crystal cured film and heating it above the phase transition temperature. Is possible. In the nematic phase or smectic phase formed by orienting the polymerizable liquid crystal compound, the polymerizable liquid crystal compounds are usually oriented so that the major axis directions are parallel to each other, and the major axis direction is the nematic phase or smectic phase. Is the orientation direction of. When such a polymerizable liquid crystal compound is formed into a film and polymerized in a nematic phase or a smectic phase, a polymer film composed of the polymer polymerized in a state oriented in the long axis direction (a) can be formed. .. This polymer film absorbs ultraviolet rays by π electrons in the long axis direction (a) and π electrons in the crossing direction (b). Here, the absorption maximum wavelength of ultraviolet rays absorbed by π electrons in the crossing direction (b) is defined as λbmax. λbmax is usually 300 nm to 400 nm. The density of π electrons satisfies the above equation (iii), and since the π electron density in the crossing direction (b) is larger than the π electron density in the major axis direction (a), the oscillating surface in the crossing direction (b). The absorption of linearly polarized ultraviolet rays (wavelength is λbmax) having a vibration plane in the long axis direction (a) is larger than the absorption of linearly polarized ultraviolet rays (wavelength is λbmax) having a vibration plane. The ratio (the ratio of the absorbance in the crossing direction (b) of the linearly polarized ultraviolet rays / the absorbance in the major axis direction (a)) is, for example, more than 1.0, preferably 1.2 or more, usually 30 or less, for example, 10 or less. Is.

In general, a polymerizable liquid crystal compound having the above characteristics often exhibits a reverse wavelength dispersibility in the birefringence of the polymer when polymerized in a state of being oriented in one direction. Specifically, for example, a compound represented by the following formula (X) can be mentioned.

In formula (X), Ar represents a divalent group having an aromatic group which may have a substituent. The aromatic group referred to here refers to a group having a ring structure having [4n + 2] π electrons according to Hückel's law, and is exemplified by (Ar-1) to (Ar-23) described later, for example. Such Ar groups may have two or more such Ar groups via a divalent linking group. Here, n represents an integer. When a ring structure is formed by including heteroatoms such as −N = and −S−, the case where the Hückel's rule is satisfied including the non-covalent bond electron pair on these heteroatoms and the aromaticity is included is also included. The aromatic group preferably contains at least one of a nitrogen atom, an oxygen atom, and a sulfur atom. The divalent group Ar may contain one aromatic group or two or more aromatic groups. When there is one aromatic group, the divalent group Ar may be a divalent aromatic group which may have a substituent. When two or more aromatic groups are contained in the divalent group Ar, the two or more aromatic groups are single-bonded to each other or bonded to each other by a divalent bonding group such as -CO-O- or -O-. May be.
G ¹ and G ² independently represent a divalent aromatic group or a divalent alicyclic hydrocarbon group, respectively. Here, the hydrogen atom contained in the divalent aromatic group or the 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, and carbon. The carbon atom constituting the divalent aromatic group or the divalent alicyclic hydrocarbon group may be substituted with an alkoxy group, a cyano group or a nitro group of the number 1 to 4, which is an oxygen atom or a sulfur atom. Alternatively, it may be substituted with a nitrogen atom.
L ¹ , L ² , B ¹ and B ² are independently single-bonded or divalent linking groups, respectively.
k and l each independently represent an integer of 0 to 3, and satisfy the relationship of 1 ≦ k + l. Here, when 2 ≦ k + l, B ¹ and B ² , G ¹ and G ² may be the same or different from each other.
Each of E ¹ and E ² independently represents an alkanediyl group having 1 to 17 carbon atoms, and an alkanediyl group having 4 to 12 carbon atoms is more preferable. Further, the hydrogen atom contained in the alkanediyl group may be substituted with a halogen atom, and -CH _2- contained in the alkanediyl group is -O-, -S-, -SiH _2- , -C. It may be replaced with (= O) −.
P ¹ and P ² independently represent a polymerizable group or a hydrogen atom, and at least one is a polymerizable group.

G ¹ and G ² are each independently 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, preferably a 1,4-phenylenediyl group. , A 1,4-cyclohexanediyl group which may be 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 1 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 no substituent. It is a substituted 1,4-trans-cyclohexanediyl group.
Further, at least one of a plurality of G ¹ and G ² present is preferably a divalent alicyclic hydrocarbon group, and at least one of ^{G 1} and G ^{2 bonded to L 1} or L ² is present. More preferably, it is a divalent alicyclic hydrocarbon group.

L ¹ and L ² are independent of each other, 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 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 or a hydrogen atom having 1 to 4 carbon atoms. 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} - in is there. ^{Wherein, R a2-1, R a4-1, R} a6-1 each independently a single _{bond, -CH 2 -, - CH 2} CH 2 - represents either. L ¹ and L ² are independent, more preferably single bonds, -O-, -CH ₂ CH _{2- , -COO-, -COOCH 2} CH _2- , or -OCO-, respectively.

B ¹ and B ² are independent of each other, preferably single bond, 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 independent, more preferably single-bonded, -OR ^a10-1- , -CH _2- , -CH ₂ CH _2- , ^{-COOR a12-1-} , or -OCOR ^a14-1- . is there. ^{Wherein, R a10-1, R a12-1, R} a14-1 each independently a single _{bond, -CH 2 -, - CH 2} CH 2 - represents either. 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 - in is there.

From the viewpoint of expressing reverse wavelength dispersibility, 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. When k = 2 and l = 2, a symmetrical structure is obtained, which is preferable.

The ^{polymerizable group represented by P 1} or P ² includes an epoxy group, a vinyl group, a vinyloxy group, a 1-chlorovinyl group, an isopropenyl group, a 4-vinylphenyl group, an acryloyloxy group, a methacryloyloxy group, and an oxylanyl group. , And an oxetanyl group and the like. Of these, an acryloyloxy group, a methylenedioxy group, a vinyl group and a vinyloxy group are preferable, and an acryloyloxy group and a methacryloyloxy group are more preferable.

Ar preferably 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, and a benzene ring and a naphthalene ring are preferable. Examples of the aromatic heterocycle 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 pyrrolin ring, an imidazole ring and a pyrazole ring. , Thiazol ring, benzothiazole ring, thienothiazole ring, oxazole ring, benzoxazole ring, phenanthroline ring and the like. Among them, it is preferable to have a thiazole ring, a benzothiazole ring, or a benzofuran ring, and it is more preferable to have a benzothiazole group. When Ar contains a nitrogen atom, the nitrogen atom preferably has π electrons.

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

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

In formulas (Ar-1) to (Ar-23), * marks represent connecting parts, and Z ⁰ , Z ¹ and Z ² are independently hydrogen atoms, halogen atoms, and alkyl 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 with 1 to 12 carbon atoms, N-alkylamino group with 1 to 12 carbon atoms, N, N-dialkylamino group with 2 to 12 carbon atoms, N-alkylsulfamoyl group with 1 to 12 carbon atoms or carbon Represents an N, N-dialkylsulfamoyl group of number 2-12. Further, Z ⁰ , Z ¹ and Z ² may contain a polymerizable group.

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

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

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

W ¹ and W ² 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 in Y ¹ , Y ² and Y ³ include an aromatic hydrocarbon group having 6 to 20 carbon atoms such as a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group and a biphenyl group, and a phenyl group. , A naphthyl group is preferable, and a phenyl group is more preferable. The aromatic heterocyclic group has 4 to 20 carbon atoms containing at least one heteroatom such as a nitrogen atom such as a frill group, a pyrrolyl group, a thienyl group, a pyridinyl group, a thiazolyl group or a benzothiazolyl group, an oxygen atom and a sulfur atom. Aromatic heterocyclic groups are mentioned, and a frill group, a thienyl group, a pyridinyl group, a thiazolyl group and a benzothiazolyl group are preferable.

Y ¹ , Y ² and Y ³ may be independently substituted polycyclic aromatic hydrocarbon groups or polycyclic aromatic heterocyclic groups, respectively. The polycyclic aromatic hydrocarbon group refers to a condensed 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 preferably hydrogen atoms, halogen atoms, alkyl groups having 1 to 12 carbon atoms, cyano groups, nitro groups, and alkoxy groups having 1 to 12 carbon atoms, respectively. ⁰ is more preferably a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, and a cyano group, and Z ¹ and Z ² are further preferably a hydrogen atom, a fluorine atom, a chlorine atom, a methyl group, and a cyano group. Further, Z ⁰ , Z ¹ and Z ² may contain a polymerizable group.

Q ¹ and ^{Q 2,} -NH -, - S -, - NR 2 '-, - O- are preferable, R ^2' is preferably a hydrogen atom. Of these, -S-, -O-, and -NH- are particularly preferable.

Among the formulas (Ar-1) to (Ar-23), the formulas (Ar-6) and (Ar-7) are preferable 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 attached and Z ^0. Examples of the aromatic heterocyclic group include those described above as the aromatic heterocycle that Ar may have. For example, a pyrrole ring, an imidazole ring, a pyrrole ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, and an indol. Examples thereof include a ring, a quinoline ring, an isoquinoline ring, a purine ring, and a pyrrolidine ring. This aromatic heterocyclic group may have a substituent. Further, Y ¹ may be a polycyclic aromatic hydrocarbon group or a polycyclic aromatic heterocyclic group which may be substituted as described above, together with the nitrogen atom to which ^{the Y 1 is bonded and Z 0.} For example, a benzofuran ring, a benzothiazole ring, a benzoxazole ring and the like can be mentioned.

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。 As a compound satisfying the above-mentioned properties (A) to (D), a compound in which Ar in the above-mentioned formula (X) is a group (II) having the following structure is also exemplified.

In formula (II), the * mark represents the 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).
Substituents X ¹ and X ² are independent, fluorine atom, chlorine atom, bromine atom, iodine atom, pentafluorosulfuranyl group, nitro group, cyano group, isocyano group, amino group, hydroxyl group, mercapto group, respectively. Methylamino group, dimethylamino group, diethylamino group, diisopropylamino group, trimethylsilyl group, dimethylsilyl group, thioisocyanogroup, or one -CH _2- or two or more non-adjacent -CH _2- are independent of each other. Then -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 linear or branched alkyl group having 1 to 20 carbon atoms which may be replaced by ≡ 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 by one or more substituents X ^3, it may be unsubstituted. Examples of the substituent X ³ include the same groups as those mentioned as the substituents X ¹ and X ^2.
U ¹ represents an organic group having 2 to 30 carbon atoms having an aromatic hydrocarbon group. Any carbon atom of the aromatic hydrocarbon group may be substituted with a heteroatom. Aromatic hydrocarbon group may be substituted by one or more of the substituents X ^3, 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 -represents. 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 having a carbon atom (which may be substituted with a hetero atom). The alkyl group, cycloalkyl group, cycloalkenyl group, and each aromatic hydrocarbon group may be substituted by one or more of the substituents X ^3, may be unsubstituted. The alkyl group may be substituted with the cycloalkyl group or the cycloalkenyl group. The alkyl one -CH ₂ in the group - or nonadjacent two or more -CH ₂ - 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−. The cycloalkyl group or cycloalkenyl one -CH in group ₂ - or nonadjacent two or more -CH ₂ - 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 the general formula (D-1), M ¹ is preferably an alkyl group having 1 to 6 carbon atoms which may be substituted with a hydrogen atom or 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 heteroatoms from the viewpoint of improving wavelength dispersibility. U ¹ is more preferably an organic group having an aromatic heterocycle which is a fused ring of a 5-membered ring and a 6-membered ring from the viewpoint of having good wavelength dispersibility and exhibiting high birefringence.

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

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

Here U ² may be substituted by one or more of the substituents X ^3, 1 single -CH 2 _- or nonadjacent two or more -CH 2 _- are each independently -O An alkyl or alkenyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, which may be replaced with −, −CO−, −COO−, −OCO−, or −O—CO—O−. It is preferably a group, a cycloalkenyl group having 3 to 12 carbon atoms, or the alkyl group or alkenyl group which may be substituted with the cycloalkyl group, cycloalkenyl group, or aryl group.

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

U ¹ and U ² may be combined to form a ring. In that case, for example, ^{a cyclic group represented by -NU 1} U ² or a cyclic group represented by -N = CU ¹ U ² can be mentioned.

^{D 1} and D ² represent groups selected from the following formulas (D-1) to (D-47), respectively, from the viewpoint that the raw materials are easily available, the solubility is good, and the birefringence is high. Is particularly preferable.

The at least one polymerizable liquid crystal compound forming the optically anisotropic film is preferably a polymerizable liquid crystal compound having a maximum absorption wavelength between the wavelengths of 300 and 400 nm. When the polymerizable liquid crystal composition contains a photopolymerization initiator, the polymerization reaction and gelation of the polymerizable liquid crystal compound may proceed during long-term storage. However, if the maximum absorption wavelength of the polymerizable liquid crystal compound is 300 to 400 nm, even if ultraviolet light is exposed during storage, the reaction active species are generated from the photopolymerization initiator and the polymerizable liquid crystal compound due to the reactive liquid compound is generated. The 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 the orientation and film thickness uniformity of the obtained optically anisotropic film can be improved. 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 capable of dissolving a polymerizable liquid crystal compound, and examples thereof include chloroform.

As a polymerizable liquid crystal compound forming an optically anisotropic film in the present invention, as long as the obtained optically anisotropic film has optical characteristics satisfying the formula (2), it generally tends to exhibit so-called positive wavelength dispersibility, as described below. A compound containing a structure represented by the formula (Y) (hereinafter, also referred to as “polymerizable liquid crystal compound (Y)”) can 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-,- Represents CS- or single bond. R ¹⁶ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
B12 and B13 are each _{independently, -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, and 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. May be substituted with a halogen atom. _{Further, -CH 2-} constituting the alkanediyl group may be replaced with -O- or -CO-. ]

The carbon number of 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, and particularly preferably in the range of 5 or 6. preferable. The hydrogen atom contained in the divalent alicyclic hydrocarbon group represented by A11 and the divalent aromatic hydrocarbon group is a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, and the like. 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, a cyclohexane-1,4-diyl group and a 1,4-phenylene group are preferable.

As E11, a linear alkanediyl group having 1 to 12 carbon atoms is preferable. _{The −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, nonan-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group and dodecane-1,12- 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- CH ₂ -CH ₂ - and _{-CH 2 -CH 2 -O-CH 2} -CH 2 -O-CH 2 -CH 2 -O-CH 2 -CH 2 - and the like.
As B11, -O-, -S-, -CO-O-, and -O-CO- are preferable, and -CO-O- is more preferable.
B12 and B13 are independently −O−, −S−, −C (= O) −, −C (= O) −O−, −OC (= O) −, and −OC. (= O) -O- is preferable, and -O- or -OC (= O) -O- is more preferable.

［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。］ As the polymerizable group represented by P11, a radically polymerizable group or a cationically polymerizable group is preferable in that it has high polymerization reactivity, particularly photopolymerization reactivity, and it is easy to handle and the liquid crystal compound itself is easy to produce. 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 or a hydrogen atom having 1 to 6 carbon atoms. ]

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

P11 is preferably a group represented by the formulas (P-14) to (P-20), more preferably a vinyl group, a p-stilbene group, an epoxy group or an oxetanyl group.
It is more preferable that 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 the formula (I), the formula (II), the formula (III), the formula (IV), the formula (V) or the 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)
[During the ceremony,
A11, B11 to B13 and P11 are synonymous with the above.
A12 to A14 are independently synonymous with A11, B14 to B16 are independently synonymous with B12, B17 is synonymous with B11, E12 is synonymous with E11, and P12 is synonymous with P11. is there.
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, and a sulfo group. _(-SO 3 H), carboxyl, alkoxycarbonyl group or a halogen atom having 1 to 10 carbon atoms, -CH ₂ constituting the alkyl group and alkoxy group - is also have I replace the -O- Good. ]

As a specific example of the polymerizable liquid crystal compound (Y), for example, "3.8.6 network (completely crosslinked type) of the liquid crystal handbook (edited by the liquid crystal handbook editorial board, published on October 30, 2000 by Maruzen Co., Ltd.)". ) ”,“ 6.5.1 Liquid crystal material b. Polymerizable nematic liquid crystal material ”, compounds having a polymerizable group, JP-A-2010-31223, JP-A-2010-270108, Examples thereof include polymerizable liquid crystal compounds described in JP-A-2011-6360 and JP-A-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. Yes, more preferably 85-98 parts by mass, still more preferably 90-95 parts by mass. When the content of the polymerizable liquid crystal compound is within the above range, the orientation order of the obtained optically anisotropic film is likely to be improved, which is advantageous. 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. The solid content of the polymerizable liquid crystal composition means all the components of the polymerizable liquid crystal composition excluding volatile components such as organic solvents.

The polymerizable liquid crystal composition used for forming the optically anisotropic film further contains additives such as a solvent, a photopolymerization initiator, a leveling agent, an antioxidant, and a photosensitizer in addition to the polymerizable liquid crystal compound. You may. As each of these components, only one kind may be used, or two or more kinds may be used in combination.

Since the polymerizable liquid crystal composition for forming an optically anisotropic film is usually applied to a substrate or the like in a state of being dissolved in a solvent, it is preferable to contain a solvent. The solvent is preferably a solvent having high solubility in the polymerizable liquid crystal compound used and being inert to the polymerization reaction of the polymerizable liquid crystal compound. Examples of the solvent include water, methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether, 1-methoxy-2-propanol, 2-butoxyethanol and alcohols such as 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. Ketone solvent; aliphatic hydrocarbon solvent such as pentane, hexane and heptane; alicyclic hydrocarbon solvent such as ethylcyclohexane; aromatic hydrocarbon solvent such as toluene and xylene; nitrile solvent such as acetonitrile; tetrahydrofuran and dimethoxyethane and the like Ether solvent; chlorine-containing solvent such as chloroform and chlorobenzene; amide-based solvent such as dimethylacetamide, dimethylformamide, N-methyl-2-pyrrolidone (NMP), 1,3-dimethyl-2-imidazolidinone, etc. Be done. These solvents can be used alone or in combination of two or more. Among these, alcohol solvents, ester solvents, ketone solvents, chlorine-containing solvents, amide solvents and aromatic hydrocarbon solvents are preferable.

The content of the solvent in the polymerizable liquid crystal composition is preferably 50 to 98 parts by mass, more preferably 70 to 95 parts by mass, based on 100 parts by mass 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 that the thickness of the film tends to be substantially uniform and unevenness tends to be less likely to occur. The solid content can be appropriately determined in consideration of the thickness of the liquid crystal cured film to be produced.

The polymerization initiator is a compound that can generate a reactive species by the contribution of heat or light and initiate a polymerization reaction such as a polymerizable liquid crystal compound. Examples of the reactive active species include active species such as radicals or cations or anions. Of these, a photopolymerization initiator that generates radicals by light irradiation is preferable from the viewpoint of easy reaction control.

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 (above, BASF Japan Co., Ltd.) (Made), Sakeol BZ, Sakeol Z, Sakeol BEE (manufactured by Seiko Kagaku Co., Ltd.), Kayacure BP100 (manufactured by Nippon Kayaku Co., Ltd.), Kayacure UVI-6992 (manufactured by Dow), ADEKA PUTMER SP- 152, ADEKA OPTMER SP-170, ADEKA OPTMER N-1717, ADEKA OPTMER N-1919, ADEKA ARCULDS NCI-831, ADEKA ARCULDS NCI-930 (all manufactured by ADEKA Corporation), TAZ-A, TAZ -PP (above, manufactured by Nippon Sibel Hegner), TAZ-104 (manufactured by Sanwa Chemical Co., Ltd.) and the like can be mentioned.
In the polymerizable liquid crystal composition for forming an optically anisotropic film, the photopolymerization initiator can be used alone or in combination of two or more.

Since the photopolymerization initiator can fully utilize the energy emitted from the light source and is excellent in productivity, the maximum absorption wavelength is preferably 300 nm to 400 nm, more preferably 300 nm to 380 nm, and above all, the α-acetophenone type. A polymerization initiator and an oxime-based photopolymerization initiator are preferable.

Examples of the α-acetophenone compound include 2-methyl-2-morpholino-1- (4-methylsulfanylphenyl) propan-1-one and 2-dimethylamino-1- (4-morpholinophenyl) -2-benzylbutane-1. −On and 2-dimethylamino-1- (4-morpholinophenyl) -2- (4-methylphenylmethyl) butane-1-one and the like can be mentioned, and more preferably 2-methyl-2-morpholino-1-( Examples thereof include 4-methylsulfanylphenyl) propan-1-one and 2-dimethylamino-1- (4-morpholinophenyl) -2-benzylbutane-1-one. Examples of commercially available α-acetophenone compounds include Irgacure 369, 379EG, 907 (above, manufactured by BASF Japan Ltd.) and Sequol 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 proceeds preferably by this radical, and among them, the oxime-based photopolymerization initiator that generates a methyl radical is preferable because the polymerization reaction initiation efficiency is high. Further, from the viewpoint of allowing the polymerization reaction to proceed more efficiently, it is preferable to use a photopolymerization initiator capable of efficiently utilizing ultraviolet rays having a wavelength of 350 nm or more. As the photopolymerization initiator capable of efficiently utilizing ultraviolet rays having a wavelength of 350 nm or more, a triazine compound or a carbazole compound having an oxime ester structure is preferable, and a carbazole compound having an oxime ester structure is more preferable from the viewpoint of sensitivity. Carbazole compounds containing an oxime ester structure include 1,2-octanedione, 1- [4- (phenylthio) -2- (O-benzoyloxime)], etanone, 1- [9-ethyl-6- (2-). Methylbenzoyl) -9H-carbazole-3-yl] -1- (O-acetyloxime) and the like can be mentioned. Commercially available oxime ester-based photopolymerization initiators include Irgacure OXE-01, Irgacure OXE-02, Irgacure OXE-03 (above, manufactured by BASF Japan Ltd.), ADEKA PUTMER N-1919, and ADEKA ARCULDS NCI-831. (The above is manufactured by ADEKA CORPORATION) and the like.

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 with respect to 100 parts by mass of the polymerizable liquid crystal compound. Is. Within the above range, the reaction of the polymerizable group proceeds sufficiently, and the orientation of the polymerizable liquid crystal compound is not easily disturbed.

The leveling agent is an additive having a function of adjusting the fluidity of the polymerizable liquid crystal composition and making the coating film obtained by applying the composition flatter. For example, silicone-based, polyacrylate-based and par. Fluoroalkyl-based leveling agents can be mentioned. Commercially available products may be used as the leveling agent, specifically, DC3PA, SH7PA, DC11PA, SH28PA, SH29PA, SH30PA, ST80PA, ST86PA, SH8400, SH8700, FZ2123 (all manufactured by Toray Dow Corning Co., Ltd.). , KP321, KP323, KP324, KP326, KP340, KP341, X22-161A, KF6001 (all manufactured by Shin-Etsu Chemical Co., Ltd.), TSF400, TSF401, TSF410, TSF4300, TSF4440, TSF4445, TSF-4446, TSF4452, TSF44 (All of which are manufactured by Momentive Performance Materials Japan LLC), Florinert (registered trademark) FC-72, FC-40, FC-43, FC-3283 (All of which are manufactured by Sumitomo 3M Co., Ltd.) ), Megafuck (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 Co., Ltd.), Ftop (trade name) EF301, EF303, EF351, EF352 (all 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 are manufactured by AGC Seimi Chemical Co., Ltd., trade name E1830, E5844 (manufactured by Daikin Fine Chemical Laboratory Co., Ltd.), BM-1000, BM-1100, BYK-352, BYK-353 and BYK-361N (any of them). (Product name: manufactured by BM Chemie) and the like. The leveling agent 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 mass, more preferably 0.05 to 3 parts by mass with respect to 100 parts by mass of the polymerizable liquid crystal compound. When the content of the leveling agent is within the above range, it is easy to orient the polymerizable liquid crystal compound, and the obtained liquid crystal cured film tends to be smoother, which is preferable.

By blending a polymerization inhibitor, the polymerization reaction of the polymerizable liquid crystal compound can be controlled. Examples of the polymerization inhibitor include phenolic compounds such as BHT, hydroquinone, alkoxy radical-containing hydroquinone, alkoxy radical-containing catechol (for example, butyl catechol), pyrogallol, 2,2,6,6-tetramethyl-1-pi. Radical supplements such as peridinyloxy radicals; thiophenols; β-naphthylamines, β-naphthols and the like.

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. It is preferably 0.1 to 5 parts by mass, and more preferably 0.1 to 3 parts by mass. The polymerization inhibitor can be used alone or in combination of two or more.

By using a photosensitizer, the photopolymerization initiator can be made highly sensitive. Examples of the photosensitizer include xanthones such as xanthones and thioxanthones; anthracenes having substituents such as anthracene and alkyl ethers; phenothiazines; rubrenes. The photosensitizer can be used alone or in combination of two or more. The content of the photosensitizer is usually 0.01 to 10 parts by mass, preferably 0.05 to 5 parts by mass, and more preferably 0.1 to 1 part by mass with respect to 100 parts by mass of the polymerizable liquid crystal compound. 3 parts by mass.

The polymerizable liquid crystal composition can be prepared by stirring the 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 composed of the horizontally oriented 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 coating film plane (hereinafter, "coating film"). Forming process "),
A step of drying the coating film to form a dry coating film (hereinafter, also referred to as a “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 liquid crystal cured film (hereinafter, also referred to as “curing step”), and
A step of immersing the obtained liquid crystal cured film in a solvent (hereinafter, also referred to as a "solvent dipping 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 on a substrate or an alignment film described later.
Examples of the base material include a glass base material and a film base material, and a resin film base material is preferable from the viewpoint of processability. Resins constituting the film substrate include, for example, polyolefins such as polyethylene, polypropylene, and norbornene-based polymers; cyclic olefin-based resins; polyvinyl alcohols; polyethylene terephthalates; polymethacrylic acid esters; polyacrylic acid esters; triacetylcellulose, Examples include diacetyl cellulose and cellulose esters such as cellulose acetate propionate; polyethylene naphthalate; polycarbonate; polysulfone; polyethersulfone; polyether ketones; polyphenylene sulfide and plastics such as polyphenylene oxide. Such a resin can be formed into a film by a known means such as a solvent casting method and a melt extrusion method to form a base material. The surface of the base material may have a protective layer formed of acrylic resin, methacrylic resin, epoxy resin, oxetane resin, urethane resin, melamine resin, etc. Surface treatment such as plasma treatment may be applied.

A commercially available product may be used as the base material. Examples of commercially available cellulose ester base materials include cellulose ester base materials manufactured by Fuji Photo Film Co., Ltd. such as Fujitac Film; manufactured by Konica Minolta Opto Co., Ltd. such as "KC8UX2M", "KC8UY", and "KC4UY". Examples include the cellulose ester base material of. Commercially available cyclic olefin resins include, for example, cyclic olefin resins manufactured by Ticona (Germany) such as "Topas (registered trademark)"; cyclic olefins manufactured by JSR Corporation such as "Arton (registered trademark)". Resins; Cyclic olefin resins manufactured by Zeon Corporation such as "ZEONOR (registered trademark)" and "ZEONEX (registered trademark)"; Mitsui such as "Apel" (registered trademark) Cyclic olefin resin manufactured by Kagaku Co., Ltd. can be mentioned. A commercially available cyclic olefin resin base material can also be used. As commercially available cyclic olefin resin base materials, cyclic olefin resin base materials manufactured by Sekisui Chemical Co., Ltd. such as "Scina (registered trademark)" and "SCA40 (registered trademark)"; "Zeonoa film (registered trademark)" A cyclic olefin resin base material manufactured by Optes Corporation; a cyclic olefin resin base material manufactured by JSR Corporation such as "Arton Film (registered trademark)" can be mentioned.

From the viewpoints of thinning the optical film including the optically anisotropic film, easy peeling of the base material, handleability of the base material, and the like, the thickness of the base material is usually 5 to 300 μm, preferably 10 to 150 μm. is there.

As a method of applying the polymerizable liquid crystal composition to a substrate or the like, a coating method such as a spin coating method, an extrusion method, a gravure coating method, a die coating method, a bar coating method, an applicator method, or a printing method such as a flexographic method is used. And the like, a known method can be mentioned.

By forming a coating film of the polymerizable liquid crystal compound on the alignment film, the polymerizable liquid crystal compound can be oriented with high accuracy. The alignment film has an orientation-regulating force that orients the polymerizable liquid crystal compound in a desired direction. For example, by using an alignment film having an orientation restricting force for horizontally aligning a polymerizable liquid crystal compound (hereinafter, also referred to as “horizontal alignment film”), optics in which the polymerizable liquid crystal compound is oriented in a direction horizontal to the film plane. An anisotropic film can be obtained. The orientation regulating force can be arbitrarily adjusted according to the type of alignment film, surface condition, rubbing conditions, etc., and when the alignment film is formed of a photoalignable polymer, it can be arbitrarily adjusted according to polarization irradiation conditions, etc. It is possible to do.

The alignment film preferably has solvent resistance that does not dissolve when the polymerizable liquid crystal composition is applied, and also has heat resistance in heat treatment for removing the solvent and aligning the polymerizable liquid crystal compound described later. Examples of the alignment film include an alignment film containing an orientation polymer, a photoalignment film, a grub alignment film having an uneven pattern or a plurality of grooves on the surface, a stretched film stretched in the orientation direction, and the like, and the accuracy of the orientation angle and From the viewpoint of quality, a photoalignment film is preferable.

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

The alignment film containing the orientation polymer is usually obtained by applying a composition in which the orientation polymer is dissolved in a solvent (hereinafter, may be referred to as "orientation polymer composition") to a base material to remove the solvent or. It is obtained by applying an oriented polymer composition to a substrate, removing the solvent, and rubbing (rubbing method). Examples of the solvent include the same solvents as those exemplified above as the 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 the range in which the oriented polymer material can be completely dissolved in the solvent, but is preferably 0.1 to 20% in terms of solid content with respect to the solution, and is 0. .1 to 10% is more preferable.

As the orientation polymer composition, a commercially available alignment film material may be used as it is. Examples of commercially available alignment film materials include Sunever (registered trademark, manufactured by Nissan Chemical Industries, Ltd.) and Optomer (registered trademark, manufactured by JSR Corporation).

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

Examples of the method for removing the solvent contained in the oriented polymer composition include a natural drying method, a ventilation drying method, a heat drying method and a vacuum drying method.

In order to impart an orientation regulating force to the alignment film, a rubbing treatment can be performed as needed (rubbing method). As a method of imparting orientation-regulating force by the rubbing method, a rubbing cloth is wrapped around a rotating rubbing roll, and an orientation polymer composition is applied to the substrate and annealed to form the surface of the substrate. A method of contacting a film of an oriented polymer can be mentioned. If masking is performed during the rubbing treatment, a plurality of regions (patterns) having different orientation directions can be formed on the alignment film.

The photo-alignment film is usually formed by applying a composition containing a polymer or monomer having a photoreactive group and a solvent (hereinafter, also referred to as “composition for forming a photo-alignment film”) to a substrate, removing the solvent, and then polarized light. It is obtained by irradiating (preferably polarized UV). The photoalignment film is also advantageous in that the direction of the orientation regulating force can be arbitrarily controlled by selecting the polarization direction of the polarized light to be irradiated.

A photoreactive group is a group that produces a liquid crystal alignment ability when irradiated with light. Specific examples thereof include groups involved in photoreactions that are the origin of liquid crystal orientation ability such as molecular orientation induction or isomerization reaction, dimerization reaction, photocrosslinking reaction or photodecomposition reaction generated by light irradiation. Of these, groups involved in the dimerization reaction or photocrosslinking reaction are preferable because they are excellent in orientation. As the photoreactive group, an unsaturated bond, particularly a group having a double bond is preferable, and a carbon-carbon double bond (C = C bond), a carbon-nitrogen double bond (C = N bond), and a nitrogen-nitrogen double bond are preferable. 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) is particularly preferable.

Examples of the photoreactive group having a C = C bond include a vinyl group, a polyene group, a stilbene group, a stillbazole group, a stillvazolium group, a chalcone group, a cinnamoyl group and the like. Examples of the photoreactive group having a C = N bond include a group having a structure 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, a maleimide group and the like. 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 an alkyl halide group.

Among them, a photoreactive group involved in the photodimerization reaction is preferable, and a photoalignment film having a relatively small amount of polarized light required for photoalignment and excellent thermal stability and stability over time can be easily obtained. A cinnamoyl group and a chalcone group are preferable. As the polymer having a photoreactive group, a polymer having a cinnamoyl group such that the terminal portion of the side chain of the polymer has a cinnamic acid structure is particularly preferable.

By applying the composition for forming a photoalignment film onto a base material, a photoalignment-inducing layer can be formed on the base material. Examples of the solvent contained in the composition include the same solvents as those exemplified above as the solvents that can be used in the polymerizable liquid crystal composition, and are 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 appropriately adjusted depending on the type of the polymer or monomer and the thickness of the target photo-alignment film, but the composition for forming a photo-alignment film. It is preferably at least 0.2% by mass, and more preferably in the range of 0.3 to 10% by mass. The composition for forming a photoalignment film may contain a polymer material such as polyvinyl alcohol or polyimide or a photosensitizer as long as the characteristics of the photoalignment film are not significantly impaired.

Examples of the method of applying the composition for forming a photoalignment film to the base material include the same method as the method of applying the orientation polymer composition to the base material. Examples of the method for removing the solvent from the applied composition for forming a photoalignment film include a natural drying method, a ventilation drying method, a heat drying method and a vacuum drying method.

In order to irradiate polarized light, even in the form of directly irradiating polarized UV from the composition for forming a photoalignment film coated on the substrate, the polarized light is transmitted from the base material side. It may be in the form of letting it irradiate. Further, it is particularly preferable that the polarized light is substantially parallel light. The wavelength of the polarized light to be irradiated is preferably in the wavelength range in which the photoreactive group of the polymer or monomer having a photoreactive group can absorb light energy. Specifically, UV (ultraviolet rays) having a wavelength in the range of 250 to 400 nm is particularly preferable. Examples of the light source used for the polarized light irradiation include xenon lamps, high-pressure mercury lamps, ultra-high pressure mercury lamps, metal halide lamps, ultraviolet light lasers such as KrF and ArF, and high-pressure mercury lamps, ultra-high pressure mercury lamps and metal halide lamps. preferable. Among these, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, and a metal halide lamp are preferable because they have a high emission intensity of ultraviolet rays having a wavelength of 313 nm. Polarized UV can be irradiated by irradiating the light from the light source through an appropriate polarizer. As such a polarizer, a polarizing filter, a polarizing prism such as Gran Thomson or Gran Tailor, or a wire grid type polarizer can be used.

By masking when rubbing or irradiating with polarized light, it is possible to form a plurality of regions (patterns) in which the directions of liquid crystal orientation are different.

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

As a method of obtaining a grub alignment film, a method of forming an uneven pattern by performing exposure and rinsing treatment after exposure through an exposure mask having a pattern-shaped slit on the surface of the photosensitive polyimide film, and a plate having a groove on the surface. A method of forming a layer of UV-curable resin before curing on a shaped master, transferring the formed resin layer to a substrate and then curing, and a film of UV-curable resin before curing formed on the substrate. Examples thereof include a method in which a roll-shaped master having a plurality of grooves is pressed to form irregularities and then cured.

The thickness of the alignment film (alignment film containing an alignment polymer or photoalignment film) is usually in the range of 10 to 10000 nm, preferably in the range of 10 to 1000 nm, more preferably 10 to 500 nm or less, and further 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 a natural drying method, a ventilation drying method, a heat drying method and a vacuum drying method. 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 a desired direction (horizontal direction) with respect to the coating film plane. Can be made to. The heating temperature of the coating film can be appropriately determined in consideration of the polymerizable liquid crystal compound to be used and the material of the base material or the like forming the coating film, but the liquid crystal phase is used to make the phase transition of the polymerizable liquid crystal compound to the liquid crystal phase state. It is usually necessary that the temperature is above the transition temperature. In order to put the polymerizable liquid crystal compound in a horizontally oriented state while removing the solvent contained in the polymerizable liquid crystal composition, for example, the liquid crystal phase transition temperature (smetic phase transition) of the polymerizable liquid crystal compound contained in the polymerizable liquid crystal composition. It can be heated to a temperature of about (temperature or nematic phase transition temperature) or higher.
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. When two or more kinds of polymerizable liquid crystal compounds are used in combination, the phase transition temperature is a polymerization in which all the polymerizable liquid crystal compounds constituting the polymerizable liquid crystal composition are mixed at the same ratio as the composition in the polymerizable liquid crystal composition. It means a temperature measured in the same manner as when one kind of polymerizable liquid crystal compound is used by using a mixture of sex liquid crystal compounds. 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 as a single substance.

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

The solvent may be removed from the coating film at the same time as heating the polymerizable liquid crystal compound to the liquid crystal phase transition temperature or higher, or separately, but it is preferable to remove the solvent at the same time from the viewpoint of improving productivity. Before heating the polymerizable liquid crystal compound to a temperature equal to or higher than the liquid crystal phase transition temperature, the solvent in the coating film is appropriately added under the condition that the polymerizable liquid crystal compound contained in the coating film obtained from the polymerizable liquid crystal composition does not polymerize. A pre-drying step may be provided for removal. Examples of the drying method in the pre-drying step include a natural drying method, a ventilation drying method, a heat drying method and a vacuum drying method, and the drying temperature (heating temperature) in the drying step is the type of polymerizable liquid crystal compound to be used and the solvent. It can be appropriately determined according to the type of the above, its boiling point, its amount and the like.

In the dry coating film obtained by the drying step, a liquid crystal cured 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, but the photopolymerization method is preferable from the viewpoint of easily controlling the polymerization reaction. In photopolymerization, the light irradiating the dry coating film includes the type of photopolymerization initiator contained in the dry coating film and the type of polymerizable liquid crystal compound (particularly, the type of polymerizable group contained in the polymerizable liquid crystal compound). And appropriately selected according to the amount thereof. Specific examples thereof 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 of active electron beams. .. Among them, ultraviolet light is preferable because it is easy to control the progress of the polymerization reaction and it is possible to use a photopolymerization apparatus widely used in the art. It is preferable to select the type of the polymerizable liquid crystal compound and the photopolymerization initiator contained in the polymerizable liquid crystal composition. Further, at the time of polymerization, the polymerization temperature can be controlled by irradiating light while cooling the dry coating film by an appropriate cooling means. By adopting such a cooling means, if the polymerizable liquid crystal compound is polymerized at a lower temperature, a liquid crystal cured film can be appropriately formed even if a base material having relatively low heat resistance is used. It is also possible to promote the polymerization reaction by raising the polymerization temperature within a range in which defects due to heat during light irradiation (deformation due to heat of the base material, etc.) do not occur. A patterned cured film can also be obtained by masking or developing 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 ultrahigh pressure mercury lamp, a xenon lamp, a halogen lamp, a carbon arc lamp, a tungsten lamp, a gallium lamp, an excima laser, and a wavelength range. Examples thereof include an LED light source that emits 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 region effective for activating the photopolymerization initiator. The time for irradiating light is usually 0.1 seconds to 10 minutes, preferably 0.1 seconds to 5 minutes, more preferably 0.1 seconds to 3 minutes, still more preferably 0.1 seconds to 1 minute. is there. When irradiated once or multiple times with such an ultraviolet irradiation intensity, the integrated light intensity is 10 to 3,000 mJ / cm ² , preferably 50 to 2,000 mJ / cm ² , and more preferably 100 to 1,000 mJ / cm. It is ^2.

In the step of immersing the liquid crystal cured film obtained in the curing step in the solvent, the refractive index nyA in the direction orthogonal to the direction of nxA in the plane of the obtained optically anisotropic film and the optically anisotropic film. The ratio of the refractive index nzA in the direction perpendicular to the plane is one of the effective treatment methods for controlling the orientation of the polymerizable liquid crystal compound so as to satisfy the formula (1). By this step, the polymerizable liquid crystal compound constituting the liquid crystal cured film, particularly the polymerizable liquid crystal compound having a T-shaped structure as described above capable of exhibiting reverse wavelength dispersibility when cured, becomes a molecule of the polymerizable liquid crystal compound. It is considered that the movement is likely to occur, and the constituent molecules arranged in the direction intersecting the long axis direction of the polymerizable liquid crystal compound are likely to be oriented in a certain direction. This makes it possible to control the directionality (orientation) of the constituent molecules of the polymerizable liquid crystal compound and 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 type of the polymerizable liquid crystal compound and the base material used. 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 them, an alcohol solvent, an ester solvent, a ketone solvent, a chlorine-containing solvent, an amide solvent and an aromatic hydrocarbon solvent are preferable, a ketone solvent is more preferable, and a ketone solvent containing a cyclic structure is further preferably contained, and a cyclic solvent is contained. It is particularly preferable to contain anone, and it is particularly preferable to contain cyclohexanone. As the solvent for the solvent immersion step, one type may be used alone, or two or more types may be used in combination. The solvent used in the solvent immersion 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 immersion step in terms of solubility in the polymerizable liquid crystal compound. On the other hand, as the solvent for the solvent immersion step, the base material used while having appropriate solubility in the polymerizable liquid crystal compound used in consideration of the influence on the base material used for forming the optically anisotropic film. It is preferable to select a solvent that does not easily affect the substrate (does not dissolve the base material).

Each condition such as the solvent temperature and the immersion time in the solvent immersion step depends on the type of the polymerizable liquid crystal compound used, the type of the solvent, the degree of polymerization of the liquid crystal cured film, and the like, and the refractive index nyA of the obtained optically anisotropic film ( The ratio of λ) to nzA (λ) can be appropriately determined so as to satisfy the equation (1). For example, in the case of continuously producing an optically anisotropic film, the solvent temperature is preferably 10 ° C. or higher, more preferably 15 ° C. or higher, further 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 10 seconds or longer, more preferably 20 seconds or longer, further preferably 30 seconds or longer, and preferably 600 seconds or shorter, more preferably 550 seconds or shorter, still more preferably 500 seconds or shorter. is there.

After the solvent immersion step, the liquid crystal cured film immersed in the solvent is dried to remove the solvent, whereby an optically anisotropic film made of the liquid crystal cured film can be obtained. The liquid crystal cured film can be dried by natural drying, ventilation drying, heat drying, vacuum drying or the like.

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

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

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 oriented retardation layer, a cured resin layer for increasing or reinforcing the mechanical strength of a liquid crystal cured film, a hard coat layer, an overcoat layer, and a viscous layer. Examples include an adhesive layer and a primer layer.

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

A film containing a stretched film having a dye having absorption anisotropy adsorbed as a polarizer is usually obtained by uniaxially stretching a polyvinyl alcohol-based resin film and dyeing the polyvinyl alcohol-based resin film with a bicolor dye. At least of the polarizer produced through a step of adsorbing a bicolor dye, a step of treating a polyvinyl alcohol-based resin film on which the bicolor dye is adsorbed with an aqueous boric acid solution, and a step of washing with water after treatment with the aqueous boric acid solution. It is produced by sandwiching one surface with a transparent protective film via an adhesive.

The polyvinyl alcohol-based resin is obtained by saponifying a polyvinyl acetate-based resin. As the polyvinyl acetate-based resin, in addition to polyvinyl acetate which is a homopolymer of vinyl acetate, a copolymer of vinyl acetate and another monomer copolymerizable therewith is 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 degree of saponification of the polyvinyl alcohol-based resin is usually about 85 to 100 mol%, preferably 98 mol% or more. The polyvinyl alcohol-based 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-based resin is usually about 1,000 to 10,000, preferably in the range of 1,500 to 5,000.

A film formed of such a polyvinyl alcohol-based resin is used as a raw film for a polarizing film. The method for forming the film of the polyvinyl alcohol-based resin is not particularly limited, and the film can be formed by a known method. The film thickness of the polyvinyl alcohol-based raw film can be, for example, about 10 to 150 μm.

The uniaxial stretching of the polyvinyl alcohol-based resin film can be performed before dyeing with a dichroic dye, at the same time as dyeing, or after dyeing. When the uniaxial stretching is performed after dyeing, the uniaxial stretching may be performed before the boric acid treatment or during the boric acid treatment. It is also possible to perform uniaxial stretching at these multiple stages. In uniaxial stretching, rolls having different peripheral speeds may be uniaxially stretched, or thermal rolls may be used to uniaxially stretch the rolls. Further, the uniaxial stretching may be a dry stretching in which stretching is performed in the atmosphere, or a wet stretching in which the polyvinyl alcohol-based resin film is swollen using a solvent. The draw ratio is usually about 3 to 8 times.

Dyeing of the polyvinyl alcohol-based resin film with a dichroic dye is performed, for example, by immersing the polyvinyl alcohol-based resin film in an aqueous solution containing the dichroic dye.

Specifically, as the dichroic dye, iodine or a dichroic organic dye is used. Examples of the dichroic organic dye include C.I. I. Examples thereof include a dichroic direct dye composed of a disazo compound such as DIRECT RED 39, and a dichroic direct dye composed of a compound such as trisazo and tetrakisazo. The polyvinyl alcohol-based resin film is preferably immersed in water before the dyeing treatment.

When iodine is used as the dichroic dye, a method of immersing a polyvinyl alcohol-based resin film in an aqueous solution containing iodine and potassium iodide for dyeing is usually adopted. The iodine content in this aqueous solution is usually about 0.01 to 1 part by mass per 100 parts by mass of water. 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 a dichroic organic dye is used as the dichroic dye, a method of immersing a polyvinyl alcohol-based resin film in an aqueous solution containing a water-soluble dichroic dye and dyeing is usually adopted. The content of the dichroic organic dye in this aqueous solution is usually ^{about 1 × 10 -4} to 10 parts by mass, preferably 1 × 10 ^-3 to 1 part by mass, more preferably 1 × 10 -4 to 1 part by mass, per 100 parts by mass 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-based resin film in an aqueous boric acid solution. The content of boric acid in this aqueous boric acid solution is usually about 2 to 15 parts by mass, preferably 5 to 12 parts by mass, per 100 parts by mass of water. When iodine is used as the bicolor dye, this boric acid aqueous solution preferably contains potassium iodide, and the content of potassium iodide in that case is usually 0.1 to 100 parts by mass of water. It 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., and more preferably 60 to 80 ° C.

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

After washing with water, a drying treatment 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 treatment time is usually about 60 to 600 seconds, preferably 120 to 600 seconds. By the drying treatment, the moisture content of the polarizer is reduced to a practical level. The water content is usually about 5 to 20% by mass, preferably 8 to 15% by mass. When the water 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 uniaxially stretching, dyeing with a dichroic dye, boric acid treatment, washing with water, and drying the polyvinyl alcohol-based resin film is preferably 5 to 40 μm.

Examples of the film coated with the dye having absorption anisotropy include a composition containing a dichroic dye having liquid crystal properties, a film obtained by applying a composition containing a dichroic dye and a polymerizable liquid crystal, and the like. Can be mentioned. The film preferably has a protective film on one or both sides thereof. Examples of the protective film include the same resin films as those exemplified above as the base material that can be used for producing the horizontally oriented liquid crystal cured film.

A film coated with a dye having absorption anisotropy is preferably thin, but if it is too thin, the strength tends to decrease and the processability tends to be inferior. 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-2012-33249.

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

The elliptical polarizing plate of the present invention is composed of the optically anisotropic film of the present invention and the polarizing film. For example, the optically anisotropic film and the polarizing film of the present invention are bonded to an adhesive layer or the like. The elliptical polarizing plate of the present invention can be obtained by laminating through the polarizing plate. Further, the elliptical polarizing plate of the present invention can be obtained by laminating a laminate obtained by removing a base material from the optical film of the present invention and a polarizing film.

In one embodiment of the present invention, when the optically anisotropic film of the present invention and the polarizing film are laminated, the angle formed by 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 them so that the temperature is ± 5 °.

The elliptical polarizing plate of the present invention may have a configuration provided by a conventional general elliptical polarizing plate, or a polarizing film and a retardation film. Such a configuration is used, for example, for the purpose of protecting the surface of an adhesive layer (sheet) for bonding an elliptical polarizing plate to a display element such as an organic EL, a polarizing film or a retardation film from scratches and stains. Protective film and the like.

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

In one aspect of the present invention, the organic EL display device is composed of a laminate including the elliptical polarizing plate of the present invention, a front plate or a touch sensor panel, and an organic EL display panel. Therefore, the present invention also covers a laminate including the elliptical polarizing plate and the front plate of the present invention, a laminate including the elliptical polarizing plate and the touch sensor panel of the present invention, and an organic EL display device including the laminate. And.

The front plate constituting the laminate including the elliptical polarizing plate and the front plate of the present invention is arranged on the visual side of the organic EL display device, and other constituent members constituting the display device are subjected to external impact, temperature and humidity, etc. It plays a role in protecting the environment from changes in the environment. The front plate is preferably made of an inorganic material such as glass or tempered glass, a polymer film, or the like. In particular, a polymer film having flexible properties is suitable as a front plate constituting a laminate for a flexible display device that can be bent.

The polymer film is usually a transparent polymer film, and its visible light transmittance is preferably 70% or more, more preferably 80% or more. Specific examples thereof include polyamide films, polyamideimide films or polyimide films, polyester films, olefin films, acrylic films, and cellulose films, which are excellent in transparency and heat resistance.

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

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

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

The touch sensor is used as an input means. As the touch sensor, there are various types such as a resistance film type, a surface acoustic wave type, an infrared method, an electromagnetic induction type, and a capacitance type, and any type may be used. The touch sensor has a substrate having flexible characteristics; a sensing pattern formed in an active region in which a user's touch is sensed on the substrate; and a sensing pattern formed in an inactive region located in an outer portion of the active region. Each sensing line for connecting to an external drive circuit via a pattern and pad may be included.

In the laminated body of the present invention, the elliptical polarizing plate, the front plate and / or the touch sensor of the present invention can be laminated by laminating each member via an adhesive layer as needed. When the laminate of the present invention contains an adhesive layer, the refractive index of the adhesive layer is the refraction of the front plate in order to suppress reflection and light scattering at the interface between the front plate and the elliptical polarizing plate and improve visibility. It is preferable to select an adhesive that is close to the index and is optically transparent.

Examples of the adhesive include water-based adhesives, organic solvent-based adhesives, solvent-free adhesives, solid adhesives, solvent volatilization adhesives, moisture-curable adhesives, heat-curable adhesives, anaerobic curable adhesives, and active energy rays. Curable adhesives, hardener-mixed adhesives, heat-melt adhesives, pressure-sensitive adhesives (adhesives), re-wet adhesives, and the like, which are widely used in the art, can be used.

The stacking order of the elliptical polarizing plate, the front plate, and the touch sensor of the present invention in the laminated body of the present invention is not particularly limited, and for example, from the visual side.
The front plate / adhesive layer / elliptical polarizing plate / adhesive layer / touch sensor may be a front plate / adhesive layer / touch sensor / adhesive layer / elliptical polarizing plate.
In the above laminated body, the organic EL display device of the present invention is manufactured by adhering the outermost layer (that is, a touch sensor or an elliptical polarizing plate) on the side opposite to the front plate of the laminated body to the organic EL display panel. be able to. The organic EL display device of the present invention is good for a long period of time by providing the optically anisotropic film of the present invention, which is unlikely to change the phase difference value with time and has excellent specular hue in a wide wavelength range of visible light. Can exhibit various image display characteristics.

Hereinafter, the present invention will be described in more detail with reference to Examples. Unless otherwise specified, "%" and "part" in the example mean mass% and parts by mass, respectively.

1. 1. Example 1
(1) Preparation of polymerizable liquid crystal composition A polymerizable liquid crystal compound (A-1) (molecular weight: 1156), a polymerizable liquid crystal compound (B-1) (molecular weight: 664) and a polymerizable liquid crystal compound (molecular weight: 664) represented by the following formulas. 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):

The 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):

The 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):

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

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

With reference to Patent Document (Japanese Unexamined Patent Publication No. 2017-179367), the liquid crystal mixture (1) is mixed with a polymerization initiator, a leveling agent, a polymerization inhibitor and a solvent according to the composition shown in Table 1, and a polymerizable liquid crystal composition is obtained. The product (1) was prepared. The amounts of the polymerization initiator, leveling agent, and polymerization inhibitor shown in Table 1 are the amounts charged with respect to 100 parts by mass of the liquid crystal mixture (1). The amount of the solvent blended was set so that the mass% of the liquid crystal mixture (1) was 10% by mass with respect to the total amount of the polymerizable liquid crystal composition (1). Specifically, a 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) butane-1-one (Irgacure (registered trademark) 369; manufactured by BASF Japan Ltd.)
Leveling agent: Polyacrylate compound (BYK-361N; manufactured by Big Chemie Japan)
Polymerization inhibitor: Dibutylhydroxytoluene (BHT; manufactured by Wako Pure Chemical Industries, Ltd.)
Solvent: N-methylpyrrolidone (NMP; manufactured by Kanto Chemical Co., Inc.)

(2) Preparation of composition for forming a photo-alignment film Mix 5 parts by mass of a photo-alignment material having the following structure and 95 parts by mass of cyclopentanone (solvent), and stir the obtained mixture at 80 ° C. for 1 hour. The composition for forming a photoalignment film (1) was obtained. The photo-oriented material represented by the following formula was synthesized by the method described in JP2013-33248.
Photo-orientation material

(3) Preparation of optical film An optical film was prepared as follows. Cycloolefin polymer film (COP) (ZF-14, manufactured by Nippon Zeon Co., Ltd., thickness 23 μm), using a corona treatment device (AGF-B10, manufactured by Kasuga Electric Works Ltd.), output 0.3 kW, processing speed 3 m / min It was processed once under the condition of. The composition for forming a photoalignment film (1) is coated on a corona-treated surface with a bar coater, dried at 80 ° C. for 1 minute, and then a polarized UV irradiation device (SPOT CURE SP-7; manufactured by Ushio Denki Co., Ltd.). ) Was used to perform polarized UV exposure with an integrated light intensity of 100 mJ / cm ^{2, and a substrate with an alignment film was obtained.} The thickness of the obtained alignment film was measured with a laser microscope (LEXT, manufactured by Olympus Corporation) and 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) having 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 coated on a substrate with an alignment film kept at 25 ° C. using a bar coater. The coating was dried at 120 ° C. for 1 minute. An optical film was produced by polymerizing a polymerizable liquid crystal compound by irradiating the dried coating film with ultraviolet rays using a high-pressure mercury lamp (Unicure VB-15201BY-A, manufactured by Ushio Denki Co., Ltd.). The integrated light intensity at the wavelength of 365 nm of the irradiated ultraviolet rays was 1000 mJ / cm ² . The irradiation with ultraviolet rays was carried out in 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 with a laser microscope (LEXT, manufactured by Olympus Corporation) and 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 taking out the optical film, 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 solvent drying, the three-dimensional refractive index, retardation value, and phase difference value change (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 A 50 mm × 50 mm × 0.7 mm Corning glass plate is provided with a pressure-sensitive adhesive having a thickness of 25 μm manufactured by Lintec Co., Ltd. After the optically anisotropic film surface (the surface opposite to the base material) of the optical film was bonded, the base material was peeled off. Then, a 23 μm cycloolefin polymer film (COP) (ZF-14, manufactured by Nippon Zeon Corporation, thickness 23 μm) was further bonded via the same pressure-sensitive pressure-sensitive adhesive to prepare a sample for evaluating the retardation value. It was confirmed that the COP used here is an optically isotropic film having a retardation value of 1 nm or less at a wavelength of 550 nm, and does not affect the evaluation of the retardation value.

For the sample for evaluation of the above retardation value, the in-plane retardation of the optically anisotropic film is changed by changing the angle of incidence of light on the sample using a measuring machine (“KOBRA-WPR” manufactured by Oji Measuring Instruments Co., Ltd.). The value and the phase difference value when tilted by 40 ° with respect to the phase advance axis were measured. The average refractive index at each wavelength was measured using an ellipsometer M-220 manufactured by JASCO Corporation. 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 phase difference value, phase difference value when tilted by 40 ° around the phase advance axis, average refractive index, and film thickness value, technical data (html: /) published by Oji Measuring Instruments Co., Ltd. The three-dimensional refractive index was calculated with reference to /www.oji-keisoku.co.jp/products/kobra/reference.html). From the obtained three-dimensional refractive index, the optical characteristics of the optically anisotropic film were calculated according to the following formula.

(Ii) Measurement of Phase Difference Value Change (ΔRe) in Durability Test The above-mentioned sample for evaluation of phase difference value was put into an air oven (PH-201 manufactured by ESPEC) controlled at 105 ° C. for 30 minutes as a durability test. Then, it was taken out and allowed to stand in an environment of 25 ° C. and 55% RH for 6 hours or more. Then, 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 equation.

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

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

4. Comparative Example 1
An optical film was prepared and evaluated in the same manner as in Example 1 except that the solvent immersion step was not performed after the irradiation with ultraviolet rays. The evaluation results are shown in Table 2.

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

Claims (11)

Equation (1):
1.002 ≤ meow (450) / nzA (450) ≤ 1.010 (1)
[In the formula (1), nyA (450) has a wavelength λ = 450 nm in the direction y orthogonal to the direction x (slow-phase axis direction) showing the highest refractive index among the in-plane main refractive indexes in the same plane. NzA (450) represents the refractive index at the wavelength λ = 450 nm in the film thickness direction of the optically anisotropic film.]
And equation (2):
ReA (450) / ReA (550) <1.00 (2)
[In equation (2), ReA (λ) represents the in-plane retardation value of the optically anisotropic film at a wavelength of λ nm, and ReA (λ) = (nxA (λ) −nyA (λ)) × dA [ In the equation, nxA (λ) represents the refractive index at a wavelength of λ nm in the plane of the optically anisotropic film, and nyA (λ) is at a wavelength of λ nm in the same plane as nxA and perpendicular to the direction of nxA. Represents the refractive index, dA indicates the film thickness of the optically anisotropic film]]
An optically anisotropic film that meets the requirements. Equation (3):
1.002 ≤ meow (550) / nzA (550) ≤ 1.010 (3)
[In the formula (3), nyA (550) has a wavelength λ = 550 nm in the direction y orthogonal to the direction x (slow phase axis direction) showing the highest refractive index among the in-plane main refractive indexes in the same plane. NzA (550) represents the refractive index at the wavelength λ = 550 nm in the film thickness direction of the optically anisotropic film.]
The optically anisotropic film according to claim 1. 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, and the polymerizable liquid crystal compound is cured in a state of being oriented horizontally with respect to an optically anisotropic film plane. The optically anisotropic film according to any one of claims 1 to 3. Equation (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 claims 1 to 4. An optical film comprising the optically anisotropic film according to any one of claims 1 to 5. An elliptical polarizing plate comprising the optically anisotropic film and the polarizing film according to any one of claims 1 to 5. The elliptical polarizing plate according to claim 7, wherein the angle formed by the slow axis of the optically anisotropic film and the absorption axis of the polarizing film is 45 ± 5 °. A laminate including the elliptical polarizing plate and the front plate according to claim 7 or 8. A laminate including the elliptical polarizing plate according to claim 7 or 8 and a touch sensor panel. An organic EL display device including the laminate according to claim 9 or 10.