TW201934725A - Liquid crystal alignment layer and method for manufacturing same, optical film and method for manufacturing same, quarter-wave plate, polarization plate, and organic electroluminescence display panel - Google Patents

Abstract

Provided is a liquid crystal alignment layer which is formed of a hardened product of an alignment layer composition containing a liquid-crystalline compound capable of exhibiting birefringence of reverse wavelength dispersion and a fluorine atom-containing surfactant, and which includes molecules of the liquid-crystalline compound in a fixed alignment state, wherein at least some of the molecules of the liquid-crystalline compound in the liquid crystal alignment layer are tilted with respect to a layer plane of the liquid crystal alignment layer, the liquid crystal alignment layer has a surface where a ratio MF/T of a surface fluorine atomic weight MF [mol%] measured by X-ray photoelectron spectroscopy with respect to the thickness T [[mu]m] of the liquid crystal alignment layer is between 3.0 and less than 16.0, and the thickness T of the liquid crystal alignment layer is not more than 2.5 [mu]m.

Description

Liquid crystal alignment layer and manufacturing method thereof, optical film and manufacturing method thereof, 1/4 wavelength plate, polarizing plate, and organic electroluminescence display panel

The invention relates to a liquid crystal alignment layer and a manufacturing method thereof, an optical film and a manufacturing method thereof, a 1/4 wavelength plate, a polarizing plate, and an organic electroluminescence display panel.

As one type of optical film, a film produced using a liquid crystal compound is known. This film generally includes a liquid crystal cured layer formed of a cured product that orients a liquid crystal composition containing a liquid crystal compound and directly cures the liquid crystal composition while maintaining the alignment state. As such an optical film, those described in Patent Document 1 have been proposed.

『Patent Literature』
"Patent Document 1": Japanese Patent No. 5363022

The liquid crystal cured layer included in the optical film usually contains a liquid crystal compound. The molecules of the liquid crystal compound may be inclined with respect to the plane of the layer of the liquid crystal cured layer. In the case where an optical film having a liquid crystal cured layer containing a liquid crystal compound with a molecular tilt is provided in an image display device, in order to obtain good viewing angle characteristics, it is desirable to appropriately adjust the tilt angle of the molecules of the liquid crystal compound.

Specifically, an organic electroluminescence display panel (hereinafter referred to as an "organic EL display panel" as appropriate) may be provided with a polarizing plate such as a circular polarizing plate or an elliptical polarizing plate on its display surface to suppress external light. The reflection suppression film is reflected. This polarizing plate is usually composed of a combination of a linear polarizer and a retardation film. From the viewpoint of suppressing reflection and obtaining excellent viewing angle characteristics when the display surface is viewed from an oblique direction, the retardation film preferably has a birefringence adjusted in its thickness direction. Then, in order to realize a retardation film having a suitable birefringence in the thickness direction, the present inventors tried to develop an optical film having a liquid crystal cured layer having a moderately adjusted tilt angle of a molecule of a liquid crystal compound.

In addition, in order to exhibit a desired optical function in a wide wavelength range, the retardation film is expected to have an in-plane retardation having a reverse wavelength dispersion property. Therefore, when a film having a liquid crystal cured layer is used as a retardation film, it is appropriate to use a birefringent liquid crystal compound (hereinafter referred to as a "reverse dispersion liquid crystal compound") that exhibits reverse wavelength dispersion properties. Expect.

However, in the conventional technology, in order to increase the inclination angle of the molecules of the reverse dispersion liquid crystalline compound contained in the liquid crystal cured layer, it is necessary to provide an alignment film different from the liquid crystal cured layer. However, a conventional liquid crystal cured layer formed using an alignment film is prone to alignment defects. Therefore, it is difficult to manufacture an optical film using an inverse dispersion liquid crystalline compound and having excellent viewing angle characteristics, while suppressing the occurrence of alignment defects in the liquid crystal cured layer.

The present invention was initiated in view of the foregoing problems, and an object thereof is to provide a liquid crystal alignment layer capable of obtaining an in-plane retardation with inverse wavelength dispersion, suppressing the occurrence of alignment defects, and excellent viewing angle characteristics, and a method for manufacturing the same; Optical film with in-plane retardation of reverse wavelength dispersion, which can suppress the occurrence of alignment defects, and excellent viewing angle characteristics; and a method of manufacturing the same; a 1/4 wavelength plate provided with the liquid crystal alignment layer or optical film; provided with the liquid crystal alignment layer or optical film A polarizing plate; and an organic electroluminescence display panel provided with the aforementioned liquid crystal alignment layer or optical film.

The present inventors devoted themselves to research to solve the aforementioned problems. As a result, the inventors have found that by using a predetermined liquid crystal alignment layer formed of a cured product of an alignment layer composition containing a "reverse dispersion liquid crystalline compound" and a "fluorine-containing surfactant", it is possible to obtain An optical film with in-plane retardation of wavelength dispersion, which can suppress the occurrence of alignment defects and has excellent viewing angle characteristics, has completed the present invention.

That is, the present invention includes the following.

[1] A liquid crystal alignment layer, which is formed of a cured product of an alignment layer composition containing "a birefringent liquid crystal compound capable of exhibiting reverse wavelength dispersion" and a "fluorine-containing surfactant", and is A liquid crystal alignment layer including molecules of the liquid crystal compound whose alignment state is fixed; wherein at least a part of molecules of the liquid crystal compound included in the liquid crystal alignment layer is inclined with respect to a layer plane of the liquid crystal alignment layer;
The liquid crystal alignment layer has a ratio of the surface fluorine atom amount M _F [mole%] measured by X-ray photoelectron spectroscopy to the thickness T [μm] of the liquid crystal alignment layer. M _F / T is 3.0 or more and less than 16.0 The thickness T of the liquid crystal alignment layer is 2.5 μm or less.

[2] The liquid crystal alignment layer according to [1], wherein a substantial maximum tilt angle of a molecule of the liquid crystal compound contained in the liquid crystal alignment layer is 26 ° or more and 60 ° or less.

[3] An optical film comprising the liquid crystal alignment layer described in [1] or [2], and a liquid crystal tilting layer formed of a cured product of a liquid crystal compound-containing tilting layer composition, wherein the liquid crystallinity The compound can exhibit birefringence of reverse wavelength dispersion that is the same as or different from the liquid crystal compound contained in the alignment layer composition; wherein the liquid crystal inclined layer is directly connected to the surface of the liquid crystal alignment layer.

[4] The optical film according to [3], wherein the in-plane retardation of the optical film at a measurement wavelength of 590 nm is 100 nm or more and 180 nm or less.

[5] A method for manufacturing a liquid crystal alignment layer, including:
A step of forming a layered body containing an alignment layer composition of a birefringent liquid crystal compound exhibiting reverse wavelength dispersion and a fluorine atom-containing surfactant;
A step of orienting the liquid crystal compound contained in the layered body of the alignment layer composition; and a step of curing the layered body of the alignment layer composition to obtain a liquid crystal alignment layer; wherein the liquid crystallinity included in the liquid crystal alignment layer is At least a part of the molecules of the compound are inclined with respect to the layer plane of the liquid crystal alignment layer, and the liquid crystal alignment layer has a surface fluorine atom amount M _F [mole%] measured by X-ray photoelectron spectroscopy and The surface where the ratio M _F / T of the thickness T [μm] is 3.0 or more and less than 16.0; and the thickness T of the liquid crystal alignment layer is 2.5 μm or less.

[6] A method for manufacturing an optical film, including:
The step of directly forming a layered body comprising a tilted layer composition of a liquid crystalline compound on the aforementioned surface of the liquid crystal alignment layer as described in [1] or [2], which can be visualized with the alignment layer composition. The same or different reverse wavelength dispersive birefringence of the aforementioned liquid crystal compounds;
A step of orienting the liquid crystal compound contained in the layer of the inclined layer composition; and a step of curing the layer of the inclined layer composition to obtain a liquid crystal inclined layer.

[7] The method for producing an optical film according to [6], wherein the step of directly forming a layer body of the inclined layer composition on the surface of the liquid crystal alignment layer includes not rubbing the surface of the liquid crystal alignment layer. The treatment is to directly form a layer body of the inclined layer composition on the surface of the liquid crystal alignment layer.

[8] A 1/4 wavelength plate comprising the liquid crystal alignment layer described in [1] or [2], or the optical film described in [3] or [4].

[9] A polarizing plate including the liquid crystal alignment layer described in [1] or [2], or the optical film described in [3] or [4].

[10] An organic electroluminescence display panel including the liquid crystal alignment layer described in [1] or [2], or the optical film described in [3] or [4].

According to the present invention, it is possible to provide a liquid crystal alignment layer having an in-plane retardation with inverse wavelength dispersion, an optical film that can suppress the occurrence of alignment defects, and excellent viewing angle characteristics, and a method for manufacturing the same; and an in-plane retardation with inverse wavelength dispersion. An optical film capable of suppressing the occurrence of alignment defects and having excellent viewing angle characteristics, and a manufacturing method thereof; a 1/4 wavelength plate provided with the liquid crystal alignment layer or the optical film; a polarizing plate provided with the liquid crystal alignment layer or the optical film; and the liquid crystal An organic electroluminescence display panel with an alignment layer or an optical film.

Examples and embodiments are disclosed below to explain the present invention in detail. However, the present invention is not limited to the examples and implementation modes disclosed below, and can be arbitrarily changed and implemented without departing from the scope of the patent application of the present invention and its equivalent scope.

In the following description, unless otherwise noted, the "in-plane direction" of a layer indicates a direction parallel to the plane of the layer.

In the following description, the "thickness direction" of a layer body means a direction perpendicular to the plane of the layer body unless otherwise noted. Therefore, unless otherwise noted, the in-plane direction of a layer is perpendicular to the thickness direction.

In the following description, unless otherwise noted, the "frontal direction" of a certain surface indicates the normal direction of the surface, and specifically refers to the direction in which the polar angle of the aforementioned surface is 0 °.

In the following description, unless otherwise noted, the "tilt direction" of a surface means a direction that is neither parallel nor perpendicular to the surface, specifically the polar angle of the aforementioned surface is 5 ° or more and 85 ° or less Range of directions.

In the following description, unless otherwise noted, inverse wavelength dispersion birefringence means "birefringence Δn (450) at a wavelength of 450 nm and birefringence Δn (550) at a wavelength of 550 nm satisfying the following formula (N1) ". Liquid crystal compounds that exhibit such a birefringence of inverse wavelength dispersion, usually exhibit longer birefringence at longer wavelengths.
Δn (450) <Δn (550) (N1)

In the following description, unless otherwise noted, the birefringence of forward wavelength dispersion refers to "birefringence Δn (450) at a wavelength of 450 nm and birefringence Δn (550) at a wavelength of 550 nm satisfying the following formula (N2) ". Liquid crystal compounds that exhibit such a birefringence of forward wavelength dispersion are usually measured at a longer wavelength, and exhibit smaller birefringence.
Δn (450) ＞ Δn (550) (N2)

In the following description, unless otherwise noted, the so-called "(meth) acrylic acid" is a term including "acrylic acid", "methacrylic acid", and combinations thereof.

In the following description, the in-plane retardation Re of a certain layer is a value represented by Re = (nx-ny) × d unless otherwise noted. Here, nx represents a refractive index in a direction (in-plane direction) perpendicular to the thickness direction of the layer body and a direction giving the maximum refractive index. ny represents the refractive index of the layer in the aforementioned in-plane direction and a direction orthogonal to the direction of nx. d represents the thickness of the layer. The retardation measurement wavelength is 590 nm unless otherwise noted. The in-plane delay Re can be measured using a phase difference meter ("AxoScan" manufactured by Axometrics).

In the following description, a resin having a positive intrinsic birefringence value means a resin whose refractive index in the direction of extension is larger than that in the direction orthogonal to it. In addition, a resin having a negative intrinsic birefringence value means a resin having a refractive index in a direction of extension that is smaller than a refractive index in a direction orthogonal thereto. The intrinsic birefringence is worth calculating from the dielectric constant distribution.

In the following description, unless otherwise noted, the direction of the slow axis of a layer refers to the direction of the slow axis of the in-plane direction.

In the following description, the directions of the elements are "parallel" and "vertical". Unless otherwise noted, within the range not impairing the effect of the present invention, for example, ± 4 °, preferably ± 3 ° The error is within the better range of ± 1 °.

In the following description, unless otherwise noted, the so-called "tilt angle" of the molecules of a liquid crystal compound contained in a layer indicates the angle between the molecules of the liquid crystal compound and the plane of the layer, and is sometimes called Is the "tilt angle". This tilt angle corresponds to the largest angle between the direction of the maximum refractive index on the refractive index ellipsoid of the molecules of the liquid crystal compound and the angle between the planes of the layer. In the following description, unless otherwise noted, the "tilt angle" means the tilt angle of the molecules of the liquid crystal compound with respect to the plane of the layer of the layer containing the liquid crystal compound. The inclination angle with respect to the plane of the layer body is sometimes referred to as "the inclination angle with respect to the in-plane direction (parallel to this plane of the layer body)".

In the following description, the "substantially maximum tilt angle" of the molecules of the liquid crystalline compound contained in a layer body means that it is assumed that the inclination angle of the molecules on one side of the layer body is 0 °, and the inclination angle of the molecules is within the thickness When the direction is changed by a certain ratio, the maximum value of the inclination angle of the molecules of the liquid crystal compound. Generally, in a layer body including a liquid crystal compound, the tilt angle of the molecules of the liquid crystal compound is smaller toward one side of the layer in the thickness direction, and larger toward the other side. The substantial maximum inclination angle indicates that the inclination angle calculated based on the assumption that the rate of change in the inclination angle in the thickness direction (that is, the rate of change that decreases toward the side and increases away from the side) is constant. The maximum value.

In the following description, the number of carbon atoms of a substituent having a substituent, unless otherwise noted, does not include the number of carbon atoms of the aforementioned substituent. According to this, for example, the description of "the alkyl group having 1 to 20 carbon atoms which may have a substituent" indicates that the alkyl group having no carbon atom having a substituent has 1 to 20 carbon atoms.

[1. Liquid crystal alignment layer]

(1.1. Overview of the liquid crystal alignment layer)

FIG. 1 is a schematic cross-sectional view of a liquid crystal alignment layer 100 according to an embodiment of the present invention. 2 is a schematic cross-sectional view of an optical film 200 according to an embodiment of the present invention.

As shown in FIGS. 1 and 2, a liquid crystal alignment layer 100 according to an embodiment of the present invention is formed on the liquid crystal alignment layer 100 to form a cured product of a liquid crystal composition containing a liquid crystal compound. A layer body of the liquid crystal tilt layer 210. The optical film 200 can be obtained by a manufacturing method including forming a liquid crystal inclined layer 210 on the liquid crystal alignment layer 100.

The liquid crystal alignment layer 100 and the liquid crystal tilt layer 210 are both equivalent to a liquid crystal cured layer that is a layer formed of a cured product of a liquid crystal composition containing a liquid crystalline compound. Layer "100 and" liquid crystal inclined layer "210. In addition, in order to distinguish the liquid crystal composition used in the liquid crystal alignment layer 100 from the liquid crystal composition used in the liquid crystal tilt layer 210, the liquid crystal composition formed in the liquid crystal alignment layer 100 is appropriately referred to as an "alignment layer." The "composition" refers to a liquid crystal composition formed for use in the liquid crystal tilt layer 210 as a "tilt layer composition". In the following description, the entire liquid crystal cured layer having a multilayer structure including the liquid crystal alignment layer 100 and the liquid crystal inclined layer 210 may be referred to as a “composite liquid crystal layer” 220.

The liquid crystal alignment layer 100 is formed of a cured product of an alignment layer composition including a reverse dispersion liquid crystal compound (that is, a birefringent liquid crystal compound exhibiting reverse wavelength dispersion) and a fluorine-based surfactant. The "fluorine-based surfactant" refers to a surfactant containing a fluorine atom.

The liquid crystal alignment layer 100 is composed of a cured product of the alignment layer composition. Therefore, the liquid crystal alignment layer 100 includes molecules of a reverse dispersion liquid crystal compound having a fixed alignment state. The term "reverse dispersion liquid crystalline compound having a fixed orientation state" includes a polymer of the reverse dispersion liquid crystalline compound. Although the liquid crystallinity of the reverse dispersion liquid crystalline compound is usually lost due to polymerization, in this application, the polymerized reverse dispersion liquid crystalline compound is also included in the term "reverse dispersion liquid crystal compound included in the liquid crystal alignment layer". The liquid crystal alignment layer 100 may also include molecules of a reverse-dispersion liquid crystal compound whose orientation state is not fixed. The molecules of the reverse-dispersion liquid crystal compound whose orientation state is fixed may be combined. It is better to fix the orientation.

Molecules of at least a part of the reverse dispersion liquid crystalline compound contained in the liquid crystal alignment layer 100 are inclined with respect to the plane of the layer body of the liquid crystal alignment layer 100 (that is, with respect to the in-plane direction). The so-called "tilt" of a molecule of a liquid crystal compound with respect to the plane of the layer (that is, relative to the in-plane direction) means that the molecule has an inclination angle of 5 ° or more with respect to the plane of the layer (that is, relative to the in-plane direction) Range below 85 °. The molecules of the liquid crystalline compound thus inclined are usually in a state that they are neither parallel nor perpendicular to the plane of the layer body (that is, to the in-plane direction).

In addition, the liquid crystal alignment layer 100 has a surface where a ratio M _F / T of a surface fluorine atom amount M _F [mole%] and a thickness T [μm] of the liquid crystal alignment layer measured by X-ray photoelectron spectroscopy is in a specified range. 100U. Hereinafter, this surface 100U is appropriately referred to as a "specific surface". Accordingly, the ratio of the surface fluorine atom amount M _F [mole%] measured by X-ray photoelectron spectroscopy to the specific surface 100U of the liquid crystal alignment layer 100 and the thickness T [μm] of the liquid crystal alignment layer 100 M _F / T is in the specified range.

The specific range of the aforementioned ratio M _F / T is usually 3.0 or more, preferably 3.2 or more, more preferably 3.5 or more, and usually less than 16.0, preferably 15.5 or less, and more preferably 15.0 or less. The surface fluorine atom amount M _F in the specific surface 100U of the liquid crystal alignment layer 100 can be used as a method for eliminating hydrogen (H) existing on the specific surface 100U of the liquid crystal alignment layer 100 by the X-ray photoelectron spectroscopy method described in the examples described later. The molar content of fluorine (F) atoms contained in all atoms is measured.

The thickness T of the liquid crystal alignment layer 100 is usually 2.5 μm or less, preferably less than 2.0 μm, more preferably 1.8 μm or less, even more preferably 1.6 μm or less, and even more preferably 1.0 μm or less. Although the lower limit of the thickness T of the liquid crystal alignment layer 100 is not particularly limited, it is preferably 0.1 μm or more, more preferably 0.2 μm or more, and particularly preferably 0.3 μm or more.

As described above, the specific surface 100U of the liquid crystal alignment layer 100 including the reverse dispersion liquid crystalline compound whose molecules are inclined with respect to the plane of the layer body (that is, with respect to the in-plane direction) has: the specific surface 100U forms an inclined layer composition. In the case of a layered body, the effect of tilting the molecules of the reverse dispersion liquid crystalline compound contained in the layered body of the inclined layer composition with respect to the plane of the layered body (that is, with respect to the in-plane direction). Therefore, according to the liquid crystal alignment layer 100, the inclination angle of the molecules of the reverse dispersion liquid crystalline compound contained in the liquid crystal inclined layer 210 formed on the specific surface 100U can be increased, so that the optical film 200 having excellent viewing angle characteristics can be obtained. In addition, since both the liquid crystal alignment layer 100 and the liquid crystal inclined layer 210 include a reverse dispersion liquid crystalline compound, the obtained optical film 200 may have an in-plane retardation of reverse wavelength dispersion. In addition, the liquid crystal alignment layer 100 can suppress alignment defects, and at the same time, orient the molecules of the reverse-dispersion liquid crystal compound so as to be inclined with respect to the plane of the layer body (that is, relative to the in-plane direction). Therefore, according to the liquid crystal alignment layer 100 as described above, it is possible to obtain an optical film 200 having in-plane retardation with reverse wavelength dispersion, which can suppress the occurrence of alignment defects, and has excellent viewing angle characteristics.

Examples of the method for adjusting the ratio M _F / T include a method of adjusting the surface fluorine atom amount M _F and the thickness T of the specific surface 100U of the liquid crystal alignment layer 100. In addition, as an adjustment method for adjusting the surface fluorine atom amount M _F of the specific surface 100U of the liquid crystal alignment layer 100, appropriate adjustments can be mentioned, for example, the type of a fluorine-based surfactant, a combination of a reverse dispersion liquid crystal compound, and a fluorine-based surfactant. And a method for the concentration of a fluorine-based surfactant in the alignment layer composition.

(1.2. Reverse Dispersive Liquid Crystal Compound)

The reverse-dispersion liquid crystalline compound is a compound having liquid crystallinity, and is generally a compound that can exhibit a liquid crystal phase when the reverse-dispersion liquid crystalline compound is aligned.

In addition, as described above, the reverse-dispersion liquid crystalline compound is a birefringent liquid crystal compound that exhibits reverse wavelength dispersion. Here, the so-called birefringent liquid crystal compound exhibiting reverse wavelength dispersion means a birefringence exhibiting reverse wavelength dispersion when a layer of the liquid crystal compound is formed and the liquid crystal compound is oriented in the layer. Liquid crystal compounds. In general, when the liquid crystal compound is uniformly aligned, it can be confirmed whether the layer of the liquid crystal compound exhibits birefringence of inverse wavelength dispersion by investigating whether the layer of the liquid crystal compound exhibits inverse wavelength dispersion. Here, the so-called uniform alignment of the liquid crystalline compound refers to forming a layer body including the liquid crystalline compound, so that the long axis direction of the mesogen skeleton of the molecules of the liquid crystalline compound in this layer body is in the same direction as the previous layer The face of the body is oriented in a direction parallel to the body. In the case where the liquid crystalline compound includes a plurality of types of mesogens having different alignment directions, the direction in which the longest type of mesogens are aligned becomes the aforementioned alignment direction. The birefringence of the layered body can be obtained from "(in-plane retardation of the layered body) ÷ (thickness of the layered body)".

The reverse-dispersion liquid crystalline compound is a compound containing a main chain mesogen and a side chain mesogen bonded to the main chain mesogen in a molecule of the reverse dispersion liquid crystalline compound. The aforementioned reverse dispersion liquid crystalline compound including a main chain mesogen and a side chain mesogen, and in a state where the reverse dispersion liquid crystalline compound is oriented, the side chain mesogen may be oriented in a direction different from the main chain mesogen. Therefore, in the layered body of the reverse-dispersive liquid crystalline compound that has been oriented in this way, the main chain mesogen and the side chain mesogen may be oriented in different directions. In this case, the birefringence of this layer appears as the difference between the refractive index corresponding to the main chain mesogen and the refractive index corresponding to the side chain mesogen, so as a result, a birefringence of inverse wavelength dispersion can be exhibited refraction.

The reverse dispersion liquid crystalline compound is preferably polymerizable. Therefore, it is preferable that the reverse-dispersion liquid crystal compound has a polymerizable group such as an acrylfluorenyl group, a methacrylfluorenyl group, and an epoxy group in its molecule. The polymerizable reverse-dispersion liquid crystalline compound can be polymerized in a state showing a liquid crystal phase, and the orientation state of the molecules maintained in the liquid crystal phase becomes a polymer. Therefore, the alignment state of the reverse dispersion liquid crystal compound can be fixed in the liquid crystal alignment layer, or the degree of polymerization of the liquid crystal compound can be increased to improve the mechanical strength of the liquid crystal alignment layer.

The molecular weight of the reverse dispersion liquid crystalline compound is preferably 300 or more, more preferably 500 or more, more preferably 800 or more, and more preferably 2000 or less, more preferably 1700 or less, and even more preferably 1500 or less. By using a reverse dispersion liquid crystalline compound having a molecular weight in this range, the coatability of the alignment layer composition can be particularly optimized.

The birefringence Δn of the reverse dispersion liquid crystalline compound at the measurement wavelength of 590 nm is preferably 0.01 or more, more preferably 0.03 or more, and more preferably 0.15 or less, and more preferably 0.10 or less. By using a reverse-dispersive liquid crystal compound having birefringence Δn in such a range, a liquid crystal alignment layer having a substantial maximum tilt angle of a molecule of the reverse-dispersive liquid crystal compound can be easily obtained. Furthermore, it is generally easy to obtain a liquid crystal alignment layer with few alignment defects by using a reverse-dispersive liquid crystal compound having birefringence Δn in such a range.

The birefringence of a liquid crystal compound can be measured by the following method, for example.

A layered body of the liquid crystal compound is prepared, and the liquid crystal compounds contained in the layered body are uniformly aligned. Then, the in-plane retardation of this layer was measured. Then, "(in-plane retardation of the layer body) ÷ (thickness of the layer body)" can be used to obtain the birefringence of the liquid crystal compound. In this case, in order to facilitate the measurement of the in-plane retardation and thickness, the layered body of the liquid crystal compound that has been uniformly aligned may be cured.

The reverse dispersion liquid crystalline compound may be used singly or in combination of two or more kinds at any ratio.

Examples of the reverse dispersion liquid crystalline compound include those represented by the following formula (I).

『Hua1』

In the formula (I), Ar represents a group represented by any one of the following formulae (II-1) to (II-7). In the formulae (II-1) to (II-7), * represents a bonding position with Z ¹ or Z ² .

『Hua 2』

In the aforementioned formulae (II-1) to (II-7), E ¹ and E ² are each independently selected from the group consisting of -CR ¹¹ R ^12- , -S-, -NR ^11- , -CO-, and -O -The foundation of a formed group. R ¹¹ and R ¹² are each independently and represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Among them, E ¹ and E ² are each preferably -S-.

In the aforementioned formulae (II-1) to (II-7), D ¹ to D ³ are each independently and represent an aromatic hydrocarbon ring group which may have a substituent or an aromatic heterocyclic group which may also have a substituent. The number of carbon atoms of the group represented by D ¹ to D ³ (the number of carbon atoms including a substituent) is independent, and is usually 2 to 100.

The number of carbon atoms of the aromatic hydrocarbon ring group in D ¹ to D ³ is preferably 6 to 30. Examples of the aromatic hydrocarbon ring group having 6 to 30 carbon atoms in D ¹ to D ³ include a phenyl group and a naphthyl group. Among them, as the aromatic hydrocarbon ring group, a phenyl group is preferred.

Examples of the substituent possessed by the aromatic hydrocarbon ring group in D ¹ to D ³ include, for example, halogen atoms such as fluorine atom and chlorine atom; cyano group; Alkyl groups; alkenyl groups having 2 to 6 carbon atoms such as vinyl and allyl groups; halogenated alkyl groups having 1 to 6 carbon atoms such as trifluoromethyl groups; N having 1 to 12 carbon atoms such as dimethylamino groups , N-dialkylamino; alkoxy having 1 to 6 carbon atoms such as methoxy, ethoxy, and isopropoxy; nitro; -OCF ₃ ; -C (= O) -R ^b ; -O-C (= O) -R b; -C (= O) -O-R b; -SO 2 R a; and the like. The number of substituents may be one or plural. Moreover, a plurality of substituents may be the same as or different from each other.

R ^a represents 6 to 20 carbon atoms selected from the group consisting of: an alkyl group having 1 to 6 carbon atoms; and an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms as a substituent. Aromatic ring groups; groups of groups.

R ^b represents a group selected from: an alkyl group having 1 to 20 carbon atoms which may have a substituent; an alkenyl group having 2 to 20 carbon atoms which may have a substituent; and 3 to 12 carbon atoms which may also have a substituent A cycloalkyl group; and an aromatic hydrocarbon ring group having 6 to 12 carbon atoms which may have a substituent; a group of groups.

The carbon number of the alkyl group having 1 to 20 carbon atoms in R ^b is preferably 1 to 12, and more preferably 4 to 10. Examples of the alkyl group having 1 to 20 carbon atoms in R ^b include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, 1-methylpentyl, and 1 -Ethylpentyl, secondary butyl, tertiary butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, isohexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, Regular eleven, regular twelve, regular thirteen, regular fourteen, regular fifteen, regular sixteen, regular seventeen, regular eighteen, regular nineteen and regular twenty .

Examples of the substituent having an alkyl group having 1 to 20 carbon atoms in R ^b include halogen atoms such as a fluorine atom and a chlorine atom; cyano groups; and carbon atoms having 2 to 12 carbon atoms such as a dimethylamino group. N, N-dialkylamino groups; alkoxy groups having 1 to 20 carbon atoms such as methoxy, ethoxy, isopropoxy, and butoxy; methoxymethoxy, methoxyethoxy, etc. Alkoxy groups having 1 to 12 carbon atoms substituted by alkoxy groups having 1 to 12 carbon atoms; nitro groups; aromatic hydrocarbon ring groups having 6 to 20 carbon atoms such as phenyl and naphthyl groups; triazolyl and pyrrolyl groups Aromatic heterocyclic groups having 2 to 20 carbon atoms, such as sulfonyl, furyl, thienyl, thiazolyl, benzothiazol-2-ylthio; cyclopropyl, cyclopentyl, and cyclohexyl Cycloalkyl; cycloalkoxy having 3 to 8 carbon atoms such as cyclopentyloxy and cyclohexyloxy; tetrahydrofuranyl, tetrahydropiperanyl, dioxy, dioxy, etc. having 2 to 12 carbon atoms Cyclic ether groups; aryloxy groups with 6 to 14 carbon atoms such as phenoxy and naphthyloxy; trifluoromethyl, pentafluoroethyl, -CH ₂ CF ₃ and more than one hydrogen atom substituted with fluorine atom Fluoroalkyl with 1 to 12 carbon atoms; benzofuranyl Benzopyran-yl; benzodioxin uh-yl; and benzodioxylmethine; and the like. The number of substituents may be one or plural. Moreover, a plurality of substituents may be the same as or different from each other.

The alkenyl group having 2 to 20 carbon atoms in R ^b preferably has 2 to 12 carbon atoms. Examples of the alkenyl group having 2 to 20 carbon atoms in R ^b include vinyl, propenyl, isopropenyl, butenyl, isobutenyl, pentenyl, hexenyl, heptenyl, and octyl Alkenyl, decenyl, undecenyl, dodecenyl, tridecenyl, tetradecenyl, pentaenyl, hexadecenyl, heptenyl, octadecenyl, undecenyl And eicosyl.

As the number of carbon atoms in the alkenyl R ^b in the group have 2 to 20 having the substituent group include an alkyl group with the number of carbon atoms in R ^b in the 1 to 20 to have the same substituent group of embodiments. The number of substituents may be one or plural. Moreover, a plurality of substituents may be the same as or different from each other.

Examples of the cycloalkyl group having 3 to 12 carbon atoms in R ^b include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cyclooctyl. Among them, cyclopentyl and cyclohexyl are preferred as the cycloalkyl group.

Examples of the substituent having a cycloalkyl group having 3 to 12 carbon atoms in R ^b include halogen atoms such as a fluorine atom and a chlorine atom; cyano groups; and a carbon number of 2 to 12 such as a dimethylamino group. N, N-dialkylamino groups; alkyl groups having 1 to 6 carbon atoms such as methyl, ethyl, and propyl; those having 1 to 6 carbon atoms such as methoxy, ethoxy, and isopropyloxy Alkoxy; nitro; and aromatic hydrocarbon ring groups having 6 to 20 carbon atoms such as phenyl and naphthyl; and the like. Among them, as a substituent of a cycloalkyl group, a halogen atom such as a fluorine atom or a chlorine atom; a cyano group; an alkyl group having 1 to 6 carbon atoms such as a methyl group, an ethyl group, or a propyl group; a methoxy group, an ethoxy group, Alkoxy groups having 1 to 6 carbon atoms such as isopropoxy; nitro groups; and aromatic hydrocarbon ring groups having 6 to 20 carbon atoms such as phenyl and naphthyl are preferred. The number of substituents may be one or plural. Moreover, a plurality of substituents may be the same as or different from each other.

Examples of the aromatic hydrocarbon ring group having 6 to 12 carbon atoms in R ^b include phenyl, 1-naphthyl, and 2-naphthyl. Among them, as the aromatic hydrocarbon ring group, a phenyl group is preferred.

Examples of the substituent having an aromatic hydrocarbon ring group having 6 to 12 carbon atoms in R ^b include halogen atoms such as fluorine atom and chlorine atom; cyano group; dimethylamino group having 2 to 12 carbon atoms N, N-dialkylamino groups; alkoxy groups having 1 to 20 carbon atoms, such as methoxy, ethoxy, isopropoxy, and butoxy; methoxymethoxy, methoxyethoxy Alkyl groups having 1 to 12 carbon atoms substituted by alkoxy groups having 1 to 12 carbon atoms; nitro groups; aromatics having 2 to 20 carbon atoms such as triazolyl, pyrrolyl, furyl, and thienyl groups Cycloyl groups; cycloalkyl groups having 3 to 8 carbon atoms such as cyclopropyl, cyclopentyl, and cyclohexyl; cycloalkoxy groups having 3 to 8 carbon atoms such as cyclopentyloxy and cyclohexyloxy; tetrahydrofuranyl, Tetrahydropiperanyl, dioxy, dioxy, and other cyclic ether groups having 2 to 12 carbon atoms; phenoxy, naphthyloxy and other aryloxy groups having 6 to 14 carbon atoms; trifluoromethyl, A fluoroalkyl group having 1 to 12 carbon atoms, in which one or more hydrogen atoms are replaced by a fluorine atom, such as pentafluoroethyl group, -CH ₂ CF ₃ ; -OCF ₃ ; benzofuranyl group; Dioxyl; benzodioxy; etc. Among them, as the substituent of the aromatic hydrocarbon ring group, a halogen atom such as a fluorine atom and a chlorine atom; a cyano group; an alkoxy group having 1 to 20 carbon atoms such as a methoxy group, an ethoxy group, an isopropoxy group, and a butoxy group; ; Nitro; furanyl, thienyl and other aromatic heterocyclic groups having 2 to 20 carbon atoms; cyclopropyl, cyclopentyl, cyclohexyl and other cycloalkyl groups having 3 to 8 carbon atoms; trifluoromethyl, penta A fluoroalkyl group having 1 to 12 carbon atoms in which at least one hydrogen atom such as fluoroethyl group, -CH ₂ CF _{3 is} replaced by a fluorine atom; -OCF _{3 is} preferred. The number of substituents may be one or plural. Moreover, a plurality of substituents may be the same as or different from each other.

The aromatic heterocyclic group in D ¹ to D ³ preferably has 2 to 30 carbon atoms. Examples of the aromatic heterocyclic group having 2 to 30 carbon atoms in D ¹ to D ³ include 1-benzofuranyl, 2-benzofuranyl, imidazolyl, indolyl, and furanyl , Oxazolyl, quinolinyl, thiadiazolyl, thiazolyl, thiazolopyryl, thiazolopyryl, thiazolopyryl, thiazolopyrimidyl, thienyl, triyl, triazolyl, pyridinyl , Pyryl, pyrazolyl, piperanyl, pyridyl, pyridyl, pyrimidinyl, pyrrolyl, fluorenyl, furyl, benzene [c] thienyl, benzene [b] thienyl, benzoisoxazolyl , Benzoisothiazolyl, benzimidazolyl, benzoxadiazolyl, benzoxazolyl, benzothiadiazolyl, benzothiazolyl, benzotriyl, benzotriazolyl, and benzo Pyrazolyl and the like. Among them, as the aromatic heterocyclic group, there are monocyclic aromatic heterocyclic groups such as furyl, piperanyl, thienyl, oxazolyl, furyl, thiazolyl, and thiadiazolyl; and benzothiazolyl and benzene Benzozolyl, quinolinyl, 1-benzofuranyl, 2-benzofuranyl, phthaloimino, benzo [c] thienyl, benzo [b] thienyl, thiazopyridyl, thiazolo Pyryl, benzoisoxazolyl, benzoxadiazolyl, and benzothiadiazolyl are more preferably aromatic heterocyclic groups.

As the aromatic heterocyclic ring in D ¹ ~ D ³ in the group to have the substituent group include the same groups as in the embodiment of the aromatic hydrocarbon ring group to have the substituent D ¹ ~ D ^3. The number of substituents may be one or plural. Moreover, a plurality of substituents may be the same as or different from each other.

In the formulae (II-1) to (II-7), D ⁴ to D ⁵ are each independently and represent a non-cyclic group which may have a substituent. D ⁴ and D ⁵ can also form a ring together. The number of carbon atoms of the group represented by D ⁴ to D ⁵ (the number of carbon atoms including the substituents) is independent, and is usually 1 to 100.

The number of carbon atoms of the non-cyclic group in D ⁴ to D ⁵ is preferably 1 to 13. Examples of the acyclic group in D ⁴ to D ⁵ include: an alkyl group having 1 to 6 carbon atoms; a cyano group; a carboxyl group; a fluoroalkyl group having 1 to 6 carbon atoms; and 1 to 6 carbon atoms _{alkoxy; -C (= O) -CH 3} ; -C (= O) NHPh; -C (= O) -OR x. Wherein, as a non-cyclic groups, cyano groups, _{carboxy, -C (= O) -CH 3} , -C (= O) NHPh, -C (= O) -OC 2 H 5, -C (= O) -OC ₄ H ₉ , -C (= O) -OCH (CH ₃ ) ₂ , -C (= O) -OCH ₂ CH ₂ CH (CH ₃ ) -OCH ₃ , -C (= O) -OCH ₂ CH ₂ C (CH ₃ ) ₂ -OH and -C (= O) -OCH ₂ CH (CH ₂ CH ₃ ) -C ₄ H _{9 are} preferred. The aforementioned Ph represents a phenyl group. In addition, the aforementioned R ^x represents an organic group having 1 to 12 carbon atoms. Specific examples of R ^x include an alkoxy group having 1 to 12 carbon atoms or an alkyl group having 1 to 12 carbon atoms which may be substituted with a hydroxyl group.

Examples of the substituent having a non-cyclic group in D ⁴ to D ⁵ include the same examples as the substituents having an aromatic hydrocarbon ring group in D ¹ to D ³ . The number of substituents may be one or plural. Moreover, a plurality of substituents may be the same as or different from each other.

When D ⁴ and D ⁵ form a ring together, a ring-containing organic group is formed by the aforementioned D ⁴ and D ⁵ . Examples of the organic group include a group represented by the following formula. In the following formula, * indicates the position of the carbon to which D ⁴ and D ⁵ are bonded in each organic group.

『Hua 3』

R ^* represents an alkyl group having 1 to 3 carbon atoms.

R ^** represents a group selected from the group consisting of an alkyl group having 1 to 3 carbon atoms and a phenyl group which may have a substituent.

R ^** represents a group selected from the group consisting of an alkyl group having 1 to 3 carbon atoms and a phenyl group which may have a substituent.

R ^{** * *} represents a group selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, a hydroxyl group, and -COOR ¹³ . R ¹³ represents an alkyl group having 1 to 3 carbon atoms.

Examples of the substituent having a phenyl group include a halogen atom, an alkyl group, an alkenyl group, an aryl group, a heterocyclic group, a hydroxyl group, a carboxyl group, an alkoxy group, an aryloxy group, a fluorenyl group, a cyano group, and an amine group. . Among these, a halogen atom, an alkyl group, a cyano group, and an alkoxy group are preferred as the substituent. The number of substituents in the phenyl group may be one or plural. Moreover, a plurality of substituents may be the same as or different from each other.

In the foregoing formulae (II-1) to (II-7), D ⁶ represents a group selected from the group consisting of -C (R ^f ) = N-N (R ^g ) R ^h , -C (R ^f ) = N-N = C (R ^g ) R ^h and -C (R ^f ) = N-N = R ⁱ . The number of carbon atoms of the group represented by D ⁶ (the number of carbon atoms including a substituent) is usually 3 to 100.

R ^f represents a group selected from the group consisting of: a hydrogen atom; and an alkyl group having 1 to 6 carbon atoms such as methyl, ethyl, propyl, and isopropyl;

R ^g represents a group selected from the group consisting of: a hydrogen atom; and an organic group having 1 to 30 carbon atoms which may have a substituent;

Examples of the organic group having 1 to 30 carbon atoms which may have a substituent in R ^g include, for example, an alkyl group having 1 to 20 carbon atoms which may have a substituent; an alkane having 1 to 20 carbon atoms. At least one of -CH ₂ -substituted by -O-, -S-, -O-C (= O)-, -C (= O) -O-, or -C (= O)- However, it excludes the case where two or more -O- or -S- are adjacent and intermediary respectively; an alkenyl group having 2 to 20 carbon atoms which may have a substituent; an alkyne having 2 to 20 carbon atoms which may have a substituent A cycloalkyl group having 3 to 12 carbon atoms, which may have a substituent; an aromatic hydrocarbon ring group having 6 to 30 carbon atoms, which may have a substituent; an aromatic group having 2 to 30 carbon atoms, which may have a substituent Heterocyclyl; -SO ₂ R ^a ; -C (= O) -R ^b ; -CS-NH-R ^b . The meaning of R ^a and R ^b is as described above.

The range and examples of a good carbon number of the alkyl group having 1 to 20 carbon atoms in R ^g are the same as those of the alkyl group having 1 to 20 carbon atoms in R ^b .

Examples of the substituent having an alkyl group having 1 to 20 carbon atoms in R ^g include halogen atoms such as a fluorine atom and a chlorine atom; cyano groups; and carbon atoms having 2 to 12 carbon atoms such as a dimethylamino group. N, N-dialkylamino groups; alkoxy groups having 1 to 20 carbon atoms such as methoxy, ethoxy, isopropoxy, and butoxy; methoxymethoxy, methoxyethoxy, etc. Alkoxy groups having 1 to 12 carbon atoms substituted by alkoxy groups having 1 to 12 carbon atoms; nitro groups; aromatic hydrocarbon ring groups having 6 to 20 carbon atoms such as phenyl and naphthyl groups; triazolyl and pyrrolyl groups Aromatic heterocyclic groups having 2 to 20 carbon atoms, such as phenyl, furyl, and thienyl; cycloalkyl groups having 3 to 8 carbon atoms such as cyclopropyl, cyclopentyl, and cyclohexyl; cyclopentyloxy, cyclohexyloxy Cycloalkoxy groups having 3 to 8 carbon atoms; cyclic ether groups having 2 to 12 carbon atoms such as tetrahydrofuranyl, tetrahydropiperanyl, dioxy, and dioxy; phenoxy, naphthyloxy, etc. Aryloxy groups with 6 to 14 carbon atoms; Fluoroalkyl groups with 1 to 12 carbon atoms with one or more hydrogen atoms replaced by fluorine atoms; benzofuranyl; benzopiperanyl; benzodioxyl ; benzodioxylmethine; -SO ₂ R ^a; -SR ^b Carbon atoms substituted by the -SR ^b group having 1 to 12 alkoxy; hydroxy; and the like. The meaning of R ^a and R ^b is as described above. The number of substituents may be one or plural. Moreover, a plurality of substituents may be the same as or different from each other.

The range and examples of good carbon number of the alkenyl group having 2 to 20 carbon atoms in R ^g are the same as those of the alkenyl group having 2 to 20 carbon atoms in R ^b .

As the number of the alkenyl carbon atoms and R ^g groups have 2 to 20 having the substituent group include the same group of embodiments and to have numbers of the alkyl R ^g of 1 to 20 carbon atoms, substituted. The number of substituents may be one or plural. Moreover, a plurality of substituents may be the same as or different from each other.

Examples of the alkynyl group having 2 to 20 carbon atoms in R ^g include ethynyl, propynyl, 2-propynyl (propargyl), butynyl, 2-butynyl, 3- Butynyl, pentynyl, 2-pentynyl, hexynyl, 5-hexynyl, heptynyl, octynyl, 2-octynyl, nonynyl, decynyl, 7-decynyl Base etc.

As the group to have the substituent R ^g alkynyl numbers of 2 to 20 carbon atoms, and examples thereof include the same group of embodiments and to have numbers of the alkyl R ^g of 1 to 20 carbon atoms, substituted. The number of substituents may be one or plural. Moreover, a plurality of substituents may be the same as or different from each other.

Examples of the cycloalkyl group having 3 to 12 carbon atoms in R ^g include the same examples as the cycloalkyl group having 3 to 12 carbon atoms in R ^b .

As the alkyl group to have the substituent group in the ring of numbers R ^g 3 to 12 carbon atoms include, for example, the same group of embodiments and to have numbers of the alkyl R ^g of 1 to 20 carbon atoms, substituted. The number of substituents may be one or plural. Moreover, a plurality of substituents may be the same as or different from each other.

Examples of the aromatic hydrocarbon ring group having 6 to 30 carbon atoms in R ^g include the same examples as the aromatic hydrocarbon ring group having 6 to 30 carbon atoms in D ¹ to D ³ .

Examples of the substituent having an aromatic hydrocarbon ring group having 6 to 30 carbon atoms in R ^g include the same examples as the substituents having an aromatic hydrocarbon ring group in D ¹ to D ³ . The number of substituents may be one or plural. Moreover, a plurality of substituents may be the same as or different from each other.

Examples of the aromatic heterocyclic group having 2 to 30 carbon atoms in R ^g include the same examples as the aromatic heterocyclic group having 2 to 30 carbon atoms in D ¹ to D ³ .

Examples of the substituent having an aromatic heterocyclic group having 2 to 30 carbon atoms in R ^g include the same examples as the substituents having an aromatic hydrocarbon ring group in D ¹ to D ³ . The number of substituents may be one or plural. Moreover, a plurality of substituents may be the same as or different from each other.

In the above, R ^g is an alkyl group having 1 to 20 carbon atoms which may have a substituent; at least one of the alkyl groups having 1 to 20 carbon atoms -CH ₂ -via -O-,- S-, -O-C (= O)-, -C (= O) -O-, or -C (= O)-substituted groups (except that more than 2 -O- or -S- are adjacent and intermediary respectively Case); cycloalkyl having 3 to 12 carbon atoms which may have a substituent; aromatic hydrocarbon ring having 6 to 30 carbon atoms which may have a substituent; and 2 carbon atoms which may have substituent A ~ 30 aromatic heterocyclic group is preferred. Among them, R ^g is an alkyl group having 1 to 20 carbon atoms which may have a substituent; and at least one of -CH ₂ -via -O-, -S included in the alkyl group having 1 to 20 carbon atoms. -, -O-C (= O)-, -C (= O) -O- or -C (= O)-substituted groups (but excluding 2 or more -O- or -S- are adjacent and intermediary respectively Situation) is particularly preferred.

R ^h represents an organic group having one or more aromatic rings selected from the group consisting of an aromatic hydrocarbon ring having 6 to 30 carbon atoms and an aromatic heterocyclic ring having 2 to 30 carbon atoms.

Preferable examples of ^Rh include (1) a cyclic hydrocarbon group having 6 to 40 carbon atoms and an aromatic hydrocarbon ring having 6 to 30 carbon atoms. Hereinafter, this cyclic hydrocarbon group having an aromatic hydrocarbon ring is referred to as "(1) cyclic hydrocarbon group" as appropriate. Specific examples of the (1) cyclic hydrocarbon group include the following groups.

『Hua 4』

(1) The cyclic hydrocarbon group may have a substituent. Examples of the substituents that (1) a cyclic hydrocarbon group has include a halogen atom such as a fluorine atom and a chlorine atom; a cyano group; an alkyl group having 1 to 6 carbon atoms such as a methyl group, an ethyl group, or a propyl group; a vinyl group, Alkenyl groups having 2 to 6 carbon atoms such as allyl groups; halogenated alkyl groups having 1 to 6 carbon atoms such as trifluoromethyl groups; N, N-dialkyl groups having 2 to 12 carbon atoms such as dimethylamino groups Amine groups; alkoxy groups having 1 to 6 carbon atoms, such as methoxy, ethoxy, and isopropoxy; nitro groups; aromatic hydrocarbon ring groups having 6 to 20 carbon atoms, such as phenyl and naphthyl; -OCF ₃ ^{; -C (= O) -R b} ; -O-C (= O) -R b; -C (= O) -O-R b; -SO 2 R a; and the like. The meaning of R ^a and R ^b is as described above. Among these, a halogen atom, a cyano group, an alkyl group having 1 to 6 carbon atoms, and an alkoxy group having 1 to 6 carbon atoms are preferred. The number of substituents may be one or plural. Moreover, a plurality of substituents may be the same as or different from each other.

As another preferred example of ^Rh , (2) one or more aromatic rings selected from the group consisting of an aromatic hydrocarbon ring having 6 to 30 carbon atoms and an aromatic heterocyclic ring having 2 to 30 carbon atoms A heterocyclic group having 2 to 40 carbon atoms. Hereinafter, this heterocyclic group having an aromatic ring is referred to as "(2) heterocyclic group" as appropriate. Specific examples of the (2) heterocyclic group include the following groups. R each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

『Hua 5』

『Hua 6』

『Hua 7』

『Hua 8』

『Hua 9』

『Hua 10』

『Hua 11』

『Hua 12』

(2) The heterocyclic group may have a substituent. As a substituent which the (2) heterocyclic group has, the same thing as the substituent which a (1) cycloalkyl group has is mentioned, for example. The number of substituents may be one or plural. Moreover, a plurality of substituents may be the same as or different from each other.

As another another good example of R ^h , (3) One or more selected from the group consisting of an aromatic hydrocarbon ring group having 6 to 30 carbon atoms and an aromatic heterocyclic group having 2 to 30 carbon atoms. Alkyl having 1 to 12 carbon atoms. This substituted alkyl group is hereinafter referred to as "(3) substituted alkyl group" as appropriate.

Examples of the "alkyl group having 1 to 12 carbon atoms" in the substituted alkyl group (3) include methyl, ethyl, propyl, and isopropyl.

Examples of the "arene ring group having 6 to 30 carbon atoms" in the substituted alkyl group (3) include the same examples as the aromatic ring group having 6 to 30 carbon atoms in D ¹ to D ³ .

Examples of the "aromatic heterocyclic group having 2 to 30 carbon atoms" in the substituted alkyl group (3) include the same examples as the aromatic heterocyclic group having 2 to 30 carbon atoms in D ¹ to D ³ .

(3) The substituted alkyl group may further have a substituent. Examples of the substituent which the (3) alkyl group has include the same examples as those of the (1) cycloalkyl group. The number of substituents may be one or plural. Moreover, a plurality of substituents may be the same as or different from each other.

As another another good example of R ^h , (4) One or more selected from the group consisting of an aromatic hydrocarbon ring group having 6 to 30 carbon atoms and an aromatic heterocyclic group having 2 to 30 carbon atoms. Alkenyl group having 2 to 12 carbon atoms substituted by a carbon group. Hereinafter, this substituted alkenyl group is appropriately referred to as "(4) substituted alkenyl group".

Examples of the "alkenyl group having 2 to 12 carbon atoms" in the (4) substituted alkenyl group include a vinyl group and an allyl group.

Examples of the "arene ring group having 6 to 30 carbon atoms" in the (4) substituted alkenyl group include the same examples as the aromatic ring group having 6 to 30 carbon atoms in D ¹ to D ³ .

Examples of the "aromatic heterocyclic group having 2 to 30 carbon atoms" in the (4) substituted alkenyl group include the same examples as the aromatic heterocyclic group having 2 to 30 carbon atoms in D ¹ to D ³ .

(4) The substituted alkenyl group may further have a substituent. Examples of the substituent possessed by the (4) substituted alkenyl group include the same examples as the substituent possessed by the (1) cyclic hydrocarbon group. The number of substituents may be one or plural. Moreover, a plurality of substituents may be the same as or different from each other.

As another another good example of R ^h , (5) One or more selected from the group consisting of an aromatic hydrocarbon ring group having 6 to 30 carbon atoms and an aromatic heterocyclic group having 2 to 30 carbon atoms. Alkynyl having 2 to 12 carbon atoms. Hereinafter, this substituted alkynyl group is appropriately referred to as "(5) substituted alkynyl group".

Examples of the "alkynyl group having 2 to 12 carbon atoms" in the (5) substituted alkynyl group include an ethynyl group and a propynyl group.

Examples of the "arene ring group having 6 to 30 carbon atoms" in the (5) substituted alkynyl group include the same examples as the aromatic ring group having 6 to 30 carbon atoms in D ¹ to D ³ .

Examples of the "aryl heterocyclic group having 2 to 30 carbon atoms" in the (5) substituted alkynyl group include the same examples as the aromatic heterocyclic group having 2 to 30 carbon atoms in D ¹ to D ³ .

(5) The substituted alkynyl group may further have a substituent. Examples of the substituent possessed by (5) substituted alkynyl include the same examples as those substituted by (1) cycloalkyl. The number of substituents may be one or plural. Moreover, a plurality of substituents may be the same as or different from each other.

As a good specific example of ^Rh , the following groups are mentioned.

『Hua 13』

More specific examples of R ^h include the following groups.

『Hua 14』

As a particularly preferable specific example of R ^h , the following groups may be mentioned.

『Hua 15』

The above-mentioned specific examples of R ^h may further have a substituent. Examples of the substituent include a halogen atom such as a fluorine atom and a chlorine atom; a cyano group; an alkyl group having 1 to 6 carbon atoms such as a methyl group, an ethyl group, or a propyl group; and a carbon atom number such as a vinyl group or an allyl group. Alkenyl groups of 2 to 6; halogenated alkyl groups having 1 to 6 carbon atoms such as trifluoromethyl; N, N-dialkylamino groups having 2 to 12 carbon atoms such as dimethylamino; methoxy, Alkoxy having 1 to 6 carbon atoms such as ethoxy and isopropoxy; nitro; -OCF ₃ ; -C (= O) -R ^b ; -O-C (= O) -R ^b ;- C (= O) -O-R ^b ; -SO ₂ R ^a ; etc. The meaning of R ^a and R ^b is as described above. Among these, a halogen atom, a cyano group, an alkyl group having 1 to 6 carbon atoms, and an alkoxy group having 1 to 6 carbon atoms are preferred. The number of substituents may be one or plural. Moreover, a plurality of substituents may be the same as or different from each other.

R ⁱ represents an organic group having one or more aromatic rings selected from the group consisting of an aromatic hydrocarbon ring having 6 to 30 carbon atoms and an aromatic hetero ring having 2 to 30 carbon atoms.

Preferable examples of R ⁱ include cyclic hydrocarbon groups having 6 to 40 carbon atoms and one or more aromatic hydrocarbon rings having 6 to 30 carbon atoms.

In addition, as another preferable example of R ⁱ , one having one or more aromatic rings selected from the group consisting of an aromatic hydrocarbon ring having 6 to 30 carbon atoms and an aromatic heterocyclic ring having 2 to 30 carbon atoms can be cited. Heterocyclic group having 2 to 40 carbon atoms.

As a particularly preferable specific example of R ⁱ , the following groups may be mentioned. The meaning of R is as described above.

『Hua 16』

The group represented by any one of formulae (II-1) to (II-7) may have a substituent in addition to D ¹ to D ⁶ . Examples of the substituent include a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 6 carbon atoms, a halogenated alkyl group having 1 to 6 carbon atoms, and an N-alkyl group having 1 to 6 carbon atoms. Amine group, N, N-dialkylamino group with 2 to 12 carbon atoms, alkoxy group with 1 to 6 carbon atoms, alkylsulfinyl sulfonyl group with 1 to 6 carbon atoms, carboxyl group, carbon number A sulfanyl group of 1 to 6, an N-alkylaminesulfonyl group having 1 to 6 carbon atoms, and an N, N-dialkylaminesulfonyl group having 2 to 12 carbon atoms. The number of substituents may be one or plural. Moreover, a plurality of substituents may be the same as or different from each other.

Preferred examples of Ar in the formula (I) include groups represented by the following formulae (III-1) to (III-10). In addition, the group represented by the formula (III-1) to the formula (III-10) may have an alkyl group having 1 to 6 carbon atoms as a substituent. In the following formula, * indicates a bonding position.

『Hua 17』

As particularly preferable specific examples of the formula (III-1) and the formula (III-4), the following groups may be mentioned. In the following formula, * indicates a bonding position.

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『Hua 19』

『Hua20』

『Chem 21』

『Hua22』

In Formula (I), Z ¹ and Z ² are each independently selected from a single bond, -O-, -O-CH _2- , -CH ₂ -O-, -O-CH ₂ -CH ₂ -,- CH ₂ -CH ₂ -O-, -C (= O) -O-, -O-C (= O)-, -C (= O) -S-, -S-C (= O)-,- ^{NR 21 -C (= O) -} , - C (= O) -NR 21 -, - CF 2 -O -, - O-CF 2 -, - CH 2 -CH 2 -, - CF 2 -CF 2 - , -O-CH ₂ -CH ₂ -O-, -CH = CH-C (= O) -O-, -O-C (= O) -CH = CH-, -CH ₂ -C (= O) -O-, -O-C (= O) -CH _2- , -CH ₂ -O-C (= O)-, -C (= O) -O-CH _2- , -CH ₂ -CH _2- C (= O) -O-, -O-C (= O) -CH ₂ -CH _2- , -CH ₂ -CH ₂ -O-C (= O)-, -C (= O) -O- CH ₂ -CH _2- , -CH = CH-, -N = CH-, -CH = N-, -N = C (CH ₃ )-, -C (CH ₃ ) = N-, -N = N- And -C≡C-any one of the group. R ^{21 is} each independently and represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

In Formula (I), A ¹ , A ² , B ^1, and B ² are each independently and represent a group selected from the group consisting of an alicyclic group which may have a substituent and an aryl group which may also have a substituent. The number of carbon atoms (including the number of carbon atoms of the substituents) of the groups represented by A ¹ , A ² , B ¹ and B ² are independent, and are usually 3 to 100. Among them, A ¹ , A ² , B ^1, and B ² are each independently, and an alicyclic group having 5 to 20 carbon atoms which may have a substituent or an aryl group having 2 to 20 carbon atoms which may also have a substituent is good.

Examples of the alicyclic group in A ¹ , A ² , B ^1, and B ² include cyclopentane-1,3-diyl, cyclohexane-1,4-diyl, and cycloheptane-1. 4,4-diyl, cyclooctane-1,5-diyl, and other cycloalkanediyl groups having 5 to 20 carbon atoms; decalin-1,5-diyl, decalin-2,6-diyl Bicycloalkanediyl with 5 to 20 carbon atoms; etc. Among them, a cycloalkanediyl group having 5 to 20 carbon atoms which can also be substituted is preferred, a cyclohexanediyl group is more preferred, and a cyclohexane-1,4-diyl group is particularly preferred. The alicyclic group may be a trans-isomer, a cis-isomer, or a mixture of a cis-isomer and a trans-isomer. Among them, trans isomers are preferred.

Examples of the substituent which the alicyclic group in A ¹ , A ² , B ¹ and B ² has include a halogen atom, an alkyl group having 1 to 6 carbon atoms, and an alkoxy group having 1 to 5 carbon atoms. Group, nitro, cyano and the like. The number of substituents may be one or plural. Moreover, a plurality of substituents may be the same as or different from each other.

Examples of the aryl group in A ¹ , A ² , B ¹ and B ² include 1,2-phenylene, 1,3-phenylene, 1,4-phenylene, 1,4- Aromatic ring groups having 6 to 20 carbon atoms, such as, for example, naphthyl, 1,5-naphthyl, 2,6-naphthyl, 4,4'-biphenyl; furan-2,5-diyl, Aromatic heterocyclic groups having 2 to 20 carbon atoms such as thiophene-2,5-diyl, pyridine-2,5-diyl, and pyr-2,5-diyl; etc. Among them, an aromatic hydrocarbon ring group having 6 to 20 carbon atoms is preferable, a phenylene group is more preferable, and a 1,4-phenylene group is particularly preferable.

For example, as mentioned in A ^1, A ^2, B ^2, and in the obtained alicyclic group having a substituent group of the same B ¹ A ^1, A ^2, B ¹ and B ² in the group to have the substituent aryl group, Example. The number of substituents may be one or plural. Moreover, a plurality of substituents may be the same as or different from each other.

In the formula (I), Y ¹ to Y ⁴ are each independently selected from a single bond, -O-, -C (= O)-, -C (= O) -O-, -O-C (= O )-, -NR ²² -C (= O)-, -C (= O) -NR ^22- , -O-C (= O) -O-, -NR ^22- C (= O) -O-, -O-C (= O) -NR ²² -and -NR ²² -C (= O) -NR ^23- . R ²² and R ²³ are each independently and represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

In Formula (I), G ¹ and G ² are each independently selected from the group consisting of an aliphatic hydrocarbon group having 1 to 20 carbon atoms; and one or more methylene groups contained in the aliphatic hydrocarbon group having 3 to 20 carbon atoms. A group (-CH _2- ) substituted by -O- or -C (= O)-; an organic group of the group. The hydrogen atom contained in the organic group of G ¹ and G ² may be substituted with an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or a halogen atom. However, the methylene groups (-CH _2- ) at both ends of G ¹ and G ^{2 are} not substituted with -O- or -C (= O)-.

Specific examples of the aliphatic hydrocarbon group having 1 to 20 carbon atoms in G ¹ and G ² include an alkylene group having 1 to 20 carbon atoms.

Specific examples of the aliphatic hydrocarbon group having 3 to 20 carbon atoms in G ¹ and G ² include an alkylene group having 3 to 20 carbon atoms.

In Formula (I), P ¹ and P ² are each independently and represent a polymerizable group. Examples of the polymerizable group in P ¹ and P ² include a group represented by CH ₂ = CR ³¹ -C (= O) -O-, such as acryloxy and methacryloxy; and ethylene; Groups; vinyl ether groups; p-distyryl groups; acrylfluorenyl groups; methacrylfluorenyl groups; carboxyl groups; methylcarbonyl groups; hydroxyl groups; amidoamino groups; Oxy; oxo; aldehyde; isocyanate; thioisocyanate; etc. R ³¹ represents a hydrogen atom, a methyl group or a chlorine atom. Among them, a base represented by CH ₂ = CR ³¹ -C (= O) -O- is preferable, and CH ₂ = CH-C (= O) -O- (propylene alkoxy), and CH ₂ = C (CH ₃ ) -C (= O) -O- (methacryloxy) is more preferred, and acryloxy is particularly preferred.

In Formula (I), p and q are each independently and represent 0 or 1.

The reverse dispersion liquid crystalline compound represented by the formula (I) can be produced by, for example, a reaction of a hydrazine compound and a carbonyl compound described in International Patent Publication No. 2012/147904.

(1.3. Fluorine surfactant)

The alignment layer composition includes a fluorine-based surfactant as a surfactant containing a fluorine atom in the molecule. When the alignment layer composition contains a fluorine-based surfactant in combination with the reverse dispersion liquid crystalline compound, the coatability of the alignment layer composition can be improved. In addition, with this fluorine-based surfactant, the surface fluorine atom amount M _F [mol%] on a specific surface of the liquid crystal alignment layer can be adjusted.

As the fluorine-based surfactant, a 1-octanol / water partition coefficient having a specified range is preferred. In the following description, the 1-octanol / water partition coefficient is referred to as "log P" in a timely manner. The specific log P range of the fluorine-based surfactant is preferably 4.8 or more, more preferably 6.7 or less, and even more preferably 6.3 or less. When the log P of the fluorine-based surfactant is at least the lower limit of the aforementioned range, it is possible to effectively suppress the occurrence of orientation defects. In addition, when the log P of the fluorine-based surfactant is equal to or lower than the upper limit of the foregoing range, the substantial maximum tilt angle of the molecules of the reverse-dispersive liquid crystal compound contained in the liquid crystal alignment layer can be effectively increased.

The log P of the fluorine-based surfactant can be measured by the following measurement method.

A sample solution containing 1% by weight of a fluorine-based surfactant was prepared, and the measurement was performed in accordance with JIS 7260-117: 2006 "Measurement of the partition coefficient (1-octanol / water)-HPLC" Methods: HPLC / ELSD analysis (high performance liquid chromatography / evaporative light scattering detection analysis) was performed, and retention time (rt) was measured. On the other hand, the value of log P described in JIS 7260-117: 2006 is a known mark compound, and HPLC / ELSD analysis was performed in comparison with the aforementioned fluorine-based surfactant to measure the residence time (r. T.). Based on the measurement results of the marker compounds, a standard curve was developed that revealed the relationship between retention time and log P. Then, the residence time measured for the fluorine-based surfactant is substituted into the standard curve described above, thereby obtaining the log P of the fluorine-based surfactant.

The specific measurement of log P of the fluorine-based surfactant can be performed by a method described in Examples described later.

The fluorine-based surfactant is preferably a nonionic surfactant. When the fluorine-based surfactant is a non-ionic surfactant that does not contain an ionic group, the surface state and orientation of the liquid crystal alignment layer can be particularly optimized.

In addition, as the fluorine-based surfactant, one having no polymerizability or one having polymerizability may be used. The polymerizable fluorine-based surfactant can be polymerized when the alignment layer composition is cured. Therefore, it is included in the liquid crystal alignment layer as part of the molecules of the polymer.

Examples of the fluorine-based surfactant include: Surflon series (S420, etc.) manufactured by AGC Seimi Chemical Co., Ltd., and FTERGENT series (251, FTX-212M, FTX-215M, FTX-209, etc.) manufactured by NEOS Corporation. , MEGAFAC series (F-444, etc.) made by DIC, etc. In addition, the fluorine-based surfactant may be used singly or in combination of two or more kinds at any ratio.

The amount of the fluorine-based surfactant is preferably adjusted so that the ratio M _F / T falls within the above-specified range. The specific amount of the fluorine-based surfactant in the alignment layer composition is preferably 0.03 parts by weight or more, more preferably 0.05 parts by weight or more, and 0.50 parts by weight based on 100 parts by weight of the reverse dispersion liquid crystalline compound. The following is preferred, and 0.30 parts by weight or less is preferred. When the amount of the fluorine-based surfactant is equal to or higher than the lower limit of the aforementioned range, the coating property of the alignment layer composition is improved, and by being equal to or lower than the upper limit of the aforementioned range, the surface state of the liquid crystal alignment layer can be improved.

(1.4. Orientation layer composition)

The alignment layer composition includes the above-mentioned reverse-dispersion liquid crystal compound and a fluorine-based surfactant, and may optionally include any component as required. An arbitrary component may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

Generally, since the alignment layer composition can be cured by polymerization, the alignment layer composition contains a polymerization initiator as an arbitrary component. The type of the polymerization initiator is selected in accordance with the type of the polymerizable compound contained in the alignment layer composition. For example, if the polymerizable compound is radical polymerizable, a radical polymerization initiator may be used. If the polymerizable compound is anionic polymerizable, an anionic polymerization initiator can be used. Furthermore, if the polymerizable compound is cationic polymerizable, a cationic polymerization initiator can be used. A polymerization initiator may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

The amount of the polymerization initiator is preferably 0.1 part by weight or more, more preferably 0.5 part by weight or more relative to 100 parts by weight of the reverse dispersion liquid crystalline compound, more preferably 30 parts by weight or less, and 10 parts by weight or less Better. When the amount of the polymerization initiator falls within the aforementioned range, the polymerization can be performed efficiently.

The alignment layer composition may include a solvent as an optional component. The solvent is preferably one which can dissolve the reverse dispersion liquid crystalline compound. As such a solvent, an organic solvent is usually used. Examples of the organic solvent include ketone solvents such as cyclopentanone, cyclohexanone, methyl ethyl ketone, acetone, and methyl isobutyl ketone; acetate solvents such as butyl acetate and amyl acetate; chloroform, Halogenated hydrocarbon solvents such as dichloromethane and dichloroethane; 1,4-dioxy, cyclopentyl methyl ether, tetrahydrofuran, tetrahydropiran, 1,3-dioxy, 1,2-dimethoxyethyl Ether solvents such as alkane; and aromatic solvents such as toluene, xylene, and 1,3,5-trimethylbenzene. The solvents may be used singly or in combination of two or more at any ratio.

From the viewpoint of excellent workability, the boiling point of the solvent is preferably 60 ° C to 250 ° C, and more preferably 60 ° C to 150 ° C.

The amount of the solvent is preferably 200 parts by weight or more, more preferably 250 parts by weight or more, more preferably 300 parts by weight or more, and preferably 650 parts by weight or less with respect to 100 parts by weight of the reverse dispersion liquid crystalline compound. It is preferably 550 parts by weight or less, and particularly preferably 450 parts by weight or less. By setting the amount of the solvent above the lower limit value of the aforementioned range, the generation of foreign matter can be suppressed, and by setting it below the upper limit value of the aforementioned range, the drying load can be reduced.

In addition, in order to further increase the inclination angle of the molecules of the inverse dispersion liquid crystalline compound contained in the liquid crystal alignment layer, the alignment layer composition may include an inclination that can increase the substantial maximum inclination angle of the molecules of the inverse dispersion liquid crystal compound. Active ingredient as an optional ingredient. Most reverse dispersion liquid crystalline compounds can only obtain small tilt angles even if they are oriented individually, but by using a tilt action component, the tilt of the molecules of the reverse dispersion liquid crystalline compound can be promoted, and the molecules of the reverse dispersion liquid crystalline compound can be easily obtained. The tilt angle is a large liquid crystal alignment layer. However, by adjusting the operation or conditions in the process of manufacturing the liquid crystal alignment layer, the inclination of the molecules of the reverse dispersion liquid crystalline compound can also be promoted. Therefore, it is not impossible to use the components without the inclination action.

Examples of the oblique action component include a para-dispersive liquid crystal compound having oblique orientation. Herein, the "para-dispersive liquid crystal compound" refers to a liquid crystal compound capable of exhibiting birefringence with a dispersion in a forward wavelength. In addition, the "cis-dispersing liquid crystalline compound having oblique orientation" refers to a composition obtained by applying a composition containing a crystalline liquid-dispersing compound alone as a liquid crystal compound to a friction-treated surface of a resin film and subjecting it to an orientation treatment to obtain a test. In the case of a layer, the molecules of the cis-dispersing liquid crystalline compound in this test layer can become a cis-dispersing liquid crystalline compound with a substantial maximum tilt angle with respect to the plane of the layer body. Such a forward-dispersing liquid crystal compound having oblique orientation can be used in combination with a fluorine-based surfactant having a log P of 4.8 or more and 6.7 or less to increase the effect of increasing the reverse-dispersion liquid crystal compound contained in the liquid crystal alignment layer. The effect of the substantial maximum tilt angle of the molecule.

Examples of the cis-dispersing liquid crystalline compound having oblique orientation include the following compounds. Further, as for the alignment layer composition containing a forward-dispersing liquid crystalline compound having oblique orientation, reference can be made to the descriptions of Japanese Patent Publication No. 2018-162379 and Japanese Patent Application No. 2017-060154.

『Hua23』

The amount of the cis-dispersing liquid crystalline compound having oblique directivity is preferably 1 part by weight or more and 5 parts by weight or more relative to 100 parts by weight of the total of the reverse-dispersing liquid crystal compound and the cis-dispersing liquid crystal compound having oblique direction. More preferably, it is more preferably 10 parts by weight or more, more preferably 25 parts by weight or less, and even more preferably 20 parts by weight or less. By using such a quantity of a forward-dispersing liquid crystal compound having oblique orientation, a liquid crystal alignment layer having a large maximum inclination angle of the molecules of the reverse-dispersing liquid crystal compound and having few alignment defects can be easily obtained.

Examples of the tilt action component include (meth) acrylate compounds having a ratio Mw / Np of a molecular weight Mw to a π-electron number Np of 17 or more and 70 or less. The ratio Mw / Np of the molecular weight Mw of the (meth) acrylate compound to the number of π electrons Np is generally 17 or more, preferably 23 or more, and usually 70 or less, and preferably 50 or less. This (meth) acrylate compound, when used in combination with a fluorine-based surfactant, has the effect of increasing the substantial maximum tilt angle of the molecules of the reverse dispersion liquid crystalline compound contained in the liquid crystal alignment layer.

The number of π electrons per one molecule of a compound is determined based on the type and number of unsaturated bonds contained in the compound. To cite examples of the number of π electrons contained in unsaturated bonds, the number of π electrons contained in an aliphatic or aromatic carbon-carbon double bond (C = C) is two, and the carbon-carbon triple bond (C≡ C) The number of π electrons contained is 4; the number of π electrons contained in the carbon-nitrogen double bond (C = N) is 2; the number of π electrons contained in the carbon-nitrogen triple bond (C≡N) is 4 The number of π electrons contained in the nitrogen-nitrogen double bond (N = N) is two.

Examples of the (meth) acrylate compound include the following. For the alignment layer composition containing the (meth) acrylate compound, reference may be made to the descriptions of International Patent Publication No. 2018/173778 and Japanese Patent Application No. 2017-060122.

『Hua 24』

『Hua25』

The amount of the (meth) acrylate compound is preferably 1 part by weight or more, more preferably 5 parts by weight or more, based on 100 parts by weight of the total of the reverse dispersion liquid crystalline compound and the (meth) acrylate compound, and It is preferably 30 parts by weight or less, and more preferably 20 parts by weight or less. When the amount of the (meth) acrylate compound falls within the aforementioned range, it is possible to increase the substantial maximum tilt angle of the molecules of the reverse dispersion liquid crystal compound contained in the liquid crystal alignment layer.

When the (meth) acrylate compound is used, the amount of the fluorine-based surfactant is preferably within a specified range. Specifically, the amount of the fluorine-based surfactant is preferably 0.11 part by weight or more, and more preferably 0.12 part by weight, based on 100 parts by weight of the total of the reverse dispersion liquid crystalline compound and the (meth) acrylate compound. Furthermore, it is preferably 0.29 parts by weight or less, more preferably 0.25 parts by weight or less, and even more preferably 0.20 parts by weight or less. When the amount of the fluorine-based surfactant is in the foregoing range, a liquid crystal alignment layer having a large maximum inclination angle of the molecules of the reverse dispersion liquid crystal compound and a large number of alignment defects can be easily obtained.

Examples of the tilt action component include a liquid crystal compound having a magnetic field response. Here, the so-called "liquid crystal compound having magnetic field responsiveness" refers to a liquid crystal compound whose orientation state can be changed by the magnetic field when a magnetic field is applied at the liquid crystal temperature. The alignment layer composition containing a liquid crystal compound having magnetic field responsiveness can exert a function of increasing a substantial maximum tilt angle of a molecule of a reverse-dispersing liquid crystal compound contained in the liquid crystal alignment layer by appropriately applying a magnetic field during the alignment process. .

Examples of the liquid crystal compound having a magnetic field response include the following. For the alignment layer composition containing a liquid crystal compound having magnetic field responsiveness, refer to the descriptions of Japanese Patent Publication No. 2018-163218 and Japanese Patent Application No. 2017-059327.

『Hua26』

The amount of the liquid crystal compound having magnetic field responsiveness is preferably 0.1 part by weight or more and more preferably 1 part by weight or more relative to 100 parts by weight of the total of the liquid crystal compound having magnetic field responsiveness and the reverse dispersion liquid crystalline compound. 3 parts by weight or more is particularly preferred, 40 parts by weight or less is preferred, 30 parts by weight or less is preferred, and 20 parts by weight or less is particularly preferred. When the amount of the liquid crystal compound having magnetic field responsiveness falls within the aforementioned range, a liquid crystal alignment layer having a large maximum inclination angle of the molecules of the reverse dispersion liquid crystal compound and a small number of alignment defects can be easily obtained.

Examples of other optional components that may be contained in the alignment layer composition include: metals; metal complexes; metal oxides such as titanium oxide; colorants such as dyes and pigments; light-emitting materials such as fluorescent materials and phosphorescent materials; leveling agents Thixotropic agents; gelling agents; polysaccharides; ultraviolet absorbers; infrared absorbers; antioxidants; ion exchange resins; etc. The amounts of these components are each 0.1 to 20 parts by weight based on 100 parts by weight of the total of the reverse dispersion liquid crystalline compound.

(1.5. Characteristics of liquid crystal alignment layer)

The liquid crystal alignment layer is a layer body in which a cured product of the alignment layer composition is cured. The curing of the alignment layer composition is usually achieved by polymerizing a polymerizable compound contained in the alignment layer composition. Therefore, the liquid crystal alignment layer usually contains a polymer of a part or all of the components contained in the alignment layer composition. For example, in the case where the reverse-dispersive liquid crystalline compound is polymerizable, since the reverse-dispersive liquid crystalline compound is polymerized, the liquid crystal alignment layer can be polymerized by including the reverse-dispersive liquid crystalline compound that is directly polymerized while maintaining the alignment state before polymerization. Layer of things. As described above, this polymerized reverse-dispersive liquid crystal compound is also included in the term "reverse-dispersive liquid crystal compound contained in the liquid crystal alignment layer".

In the cured product of the alignment layer composition, since the fluidity before curing is lost, the orientation state of the reverse dispersion liquid crystalline compound is usually directly fixed in the orientation state before curing. Further, molecules of at least a part of the reverse-dispersion liquid crystal compound contained in the liquid crystal alignment layer are inclined with respect to a layer body plane (that is, with respect to an in-plane direction) of the liquid crystal alignment layer.

In the liquid crystal alignment layer, among the molecules of the liquid crystal compound with reverse dispersion, a part may be inclined with respect to the plane of the layer body of the liquid crystal alignment layer (that is, with respect to the in-plane direction), or it may be all with respect to the liquid crystal alignment layer. The plane of the layer body (that is, relative to the in-plane direction) is inclined. Generally, in the liquid crystal alignment layer, the inclination angle of the molecules of the reverse-dispersion liquid crystal compound is larger toward the specific surface in the thickness direction, and smaller toward the specific surface. Therefore, in the vicinity of a specific surface of the liquid crystal alignment layer, the molecules of the reverse-dispersing liquid crystalline compound may be perpendicular to the plane of the layer body (that is, relative to the in-plane direction). In addition, in the adjacent portion of the liquid crystal alignment layer on a surface opposite to the specific surface, the molecules of the reverse-dispersion liquid crystalline compound may be parallel with respect to the plane of the layer body (that is, with respect to the in-plane direction). However, even in the case where the molecules of the inverse dispersion liquid crystalline compound are parallel or perpendicular with respect to the plane of the layer body (that is, with respect to the in-plane direction) in the vicinity of the surface of the liquid crystal alignment layer, generally, the surface of the liquid crystal alignment layer is excluded. In the adjacent part, the molecules of the inverse dispersion liquid crystalline compound will still be inclined with respect to the plane of the layer body (that is, with respect to the in-plane direction).

The molecules of at least a part of the reverse dispersion liquid crystalline compound contained in the liquid crystal alignment layer can be tilted with respect to the layer body plane (that is, with respect to the in-plane direction) of the liquid crystal alignment layer by using a polarizing microscope with sufficient resolution. The cross section of the liquid crystal alignment layer was observed to confirm it. In order to make the inclination of the molecules of the reverse dispersion liquid crystalline compound easier to observe, this observation can also be carried out by inserting a wavelength plate between the observation sample and the objective lens of the polarizing microscope as a test plate.

Alternatively, the fact that at least a part of the molecules of the reverse-dispersion liquid crystalline compound contained in the liquid crystal alignment layer is inclined with respect to the plane of the layer body of the liquid crystal alignment layer (that is, with respect to the in-plane direction) can be confirmed as described below. The retardation R (θ) of the liquid crystal alignment layer at an incident angle θ is measured in a measurement direction perpendicular to the fast axis direction in the plane of the liquid crystal alignment layer. Then, the retardation R (θ) of the liquid crystal alignment layer at the incident angle θ is divided by the retardation R (0 °) of the liquid crystal alignment layer at the incident angle 0 °, and the retardation ratio R (θ) / R (0 °) is obtained. . In the case of plotting a graph with the retardation ratio R (θ) / R (0 °) thus obtained as the vertical axis and the incident angle θ as the horizontal axis, as long as the graph obtained is not valid for θ = 0 ° Symmetrically, it can be confirmed that at least a part of the molecules of the reverse dispersion liquid crystalline compound included in the liquid crystal alignment layer is inclined with respect to the plane of the layer body of the liquid crystal alignment layer (that is, with respect to the in-plane direction).

The following examples illustrate this in more detail. FIG. 3 is a graph plotting a retardation ratio R (θ) / R (0 °) of a related example liquid crystal alignment layer against an incident angle θ. If the inclination angle of all molecules of the reverse dispersion liquid crystalline compound contained in the liquid crystal alignment layer is 0 ° or 90 °, the retardation ratio R (θ) / R (0 °) is as shown in the example shown by the dotted line in FIG. 3 , Will be linearly symmetric with respect to a straight line of θ = 0 ° (through the vertical axis of θ = 0 ° in FIG. 3). On the other hand, if at least a part of the molecules of the reverse-dispersing liquid crystal compound contained in the liquid crystal alignment layer is inclined with respect to the plane of the layer body of the liquid crystal alignment layer (that is, with respect to the in-plane direction), the retardation ratio R (θ) / R (0 °), as shown by the solid line in FIG. 3, is generally asymmetric with respect to a straight line of θ = 0 °. Therefore, when the retardation ratio R (θ) / R (0 °) is asymmetric with respect to θ = 0 °, it can be determined that at least a part of the molecules of the reverse dispersion liquid crystalline compound contained in the liquid crystal alignment layer are relative to the liquid crystal. The layer body plane of the alignment layer (ie, relative to the in-plane direction) is inclined.

Since the liquid crystal alignment layer contains molecules of a reverse-dispersing liquid crystalline compound which is inclined with respect to the plane of the layer body of the liquid crystal alignment layer (that is, with respect to the in-plane direction), the liquid crystal alignment layer usually has a substantial maximum tilt angle of 5 ° or more and 85 ° or less. In a liquid crystal alignment layer, this substantial maximum tilt angle indicates that the molecules having a tilt angle of 0 ° on the surface opposite to a specific surface of the liquid crystal alignment layer are 0 °, and the tilt angle of the molecules changes at a certain ratio in the thickness direction. In this case, the maximum value of the tilt angle of the molecules of the reverse dispersion liquid crystalline compound. This substantial maximum tilt angle is an index that reveals the magnitude of the tilt angle of the molecules of the reverse dispersion liquid crystalline compound contained in the liquid crystal alignment layer. In general, the more the liquid crystal alignment layer having a substantially larger maximum tilt angle, the larger the tilt angle as seen by the entire molecules of the reverse-dispersing liquid crystal compound contained in the liquid crystal alignment layer.

In an optical film manufactured using a liquid crystal alignment layer, generally, the larger the substantial maximum tilt angle of the molecules of the reverse-dispersing liquid crystal compound contained in the liquid crystal alignment layer, the larger the reverse dispersion liquid crystal compound contained in the liquid crystal tilt layer can be increased. The substantial maximum tilt angle of the molecules, as a result, the substantial maximum tilt angle of the molecules of the reverse dispersion liquid crystal compound contained in the composite liquid crystal layer can be increased. In addition, in such a composite liquid crystal layer having a substantially large maximum tilt angle, since the tilt angle of the molecules of the reverse dispersion liquid crystalline compound contained in the composite liquid crystal layer is large, an optical film having the composite liquid crystal layer is provided as a reflection. In the case of a polarizing plate that suppresses a thin film, the birefringence in the thickness direction can be adjusted appropriately. Therefore, according to this optical film, reflection can be effectively suppressed in the oblique direction of the display surface, and thus the viewing angle characteristics can be improved.

The range of the substantial maximum tilt angle of the molecules of the reverse-dispersing liquid crystal compound contained in the liquid crystal alignment layer is such that the substance of the molecules of the reverse-dispersing liquid crystal compound contained in the entire composite liquid crystal layer including the liquid crystal alignment layer and the liquid crystal tilt layer is the largest. The inclination angle is appropriately adjusted to fall within a range where excellent viewing angle characteristics can be achieved. In general, the larger the substantial maximum tilt angle of the liquid crystal alignment layer, the larger the substantial maximum tilt angle of the entire composite liquid crystal layer including the liquid crystal alignment layer and the liquid crystal tilt layer. The specific range of the substantial maximum tilt angle of the molecules of the reverse dispersion liquid crystalline compound contained in the liquid crystal alignment layer is preferably 26 ° or more, more preferably 28 ° or more, particularly preferably 30 ° or more, and 60 ° The following is better. Since the substantially maximum tilt angle of the molecules of the reverse-dispersing liquid crystal compound contained in the liquid crystal alignment layer is in the aforementioned range, it is easy to manufacture an optical film having particularly excellent viewing angle characteristics.

The substantial maximum tilt angle of the molecules of the reverse-dispersion liquid crystal compound contained in the liquid crystal alignment layer can be measured by a measurement method described in Examples described later. According to the measurement method described in the examples described later, even when the liquid crystal alignment layer contains a liquid crystal compound other than the reverse dispersion liquid crystalline compound, the substantial maximum tilt angle of the molecules of the reverse dispersion liquid crystalline compound can be measured with energy.

In the in-plane direction of the liquid crystal alignment layer, the alignment direction of the molecules of the reverse dispersion liquid crystalline compound is generally uniform. Therefore, the liquid crystal alignment layer usually has an in-plane slow axis that is parallel to the alignment direction of the molecules of the reverse dispersion liquid crystalline compound when viewed from the thickness direction. In addition, since the liquid crystal compound having a reverse dispersion in the in-plane direction is aligned in a certain alignment direction, the liquid crystal alignment layer usually has an in-plane retardation of a predetermined size.

The liquid crystal alignment layer is formed of a cured product of an alignment layer composition containing a reverse-dispersion liquid crystalline compound, and therefore generally has an in-plane retardation of reverse wavelength dispersion. Here, the in-plane retardation of inverse wavelength dispersion refers to the "in-plane retardation Re (450) at a wavelength of 450 nm and the in-plane retardation Re (550) at a wavelength of 550 nm satisfying the following formula (N3)" In-plane delay. Among them, the in-plane retardation of the liquid crystal alignment layer preferably satisfies the following formula (N4). By combining such a liquid crystal alignment layer having in-plane retardation with reverse wavelength dispersion and a liquid crystal tilting layer, an optical film having in-plane retardation with reverse wavelength dispersion can be obtained.
Re (450) / Re (550) <1.00 (N3)
Re (450) / Re (550) <0.90 (N4)

The specific in-plane retardation range of the liquid crystal alignment layer can be arbitrarily set depending on the application of the optical film manufactured using the liquid crystal alignment layer. In particular, in order to combine an optical film and a linear polarizer to obtain a polarizing plate as a reflection suppressing film for an organic EL display panel, the in-plane retardation of the liquid crystal alignment layer is set so as to obtain a function capable of functioning as a 1/4 wavelength plate. The optical film is as expected.

In the liquid crystal alignment layer, the occurrence of alignment defects is suppressed. In addition, as described later, the liquid crystal alignment layer has a high affinity for the composition of the inclined layer. Therefore, the composition of the inclined layer is compatible with the liquid crystal alignment layer, and the alignment of the molecules is not easily confused. Accordingly, the orientation state can be made uniform in the in-plane direction in the composition of the inclined layer. Therefore, according to this liquid crystal alignment layer, even in a liquid crystal inclined layer formed on the liquid crystal alignment layer, the occurrence of alignment defects can be suppressed. Therefore, the occurrence of alignment defects in the entire composite liquid crystal layer including the liquid crystal alignment layer and the liquid crystal inclined layer can be suppressed. In particular, the liquid crystal alignment layer is excellent in terms of suppressing the occurrence of alignment defects and increasing the substantial maximum tilt angle of the molecules of the reverse dispersion liquid crystalline compound. The mechanism in which the present inventors speculate that such an advantage can be obtained is as follows.

FIG. 4 is a schematic cross-sectional view illustrating a layer body 300 of an alignment layer composition obtained during a manufacturing process of a liquid crystal alignment layer according to an embodiment.

As shown in FIG. 4, in the method for manufacturing a liquid crystal alignment layer, an alignment process is generally performed in which the layer body 300 of the alignment layer composition is adjusted to an appropriate temperature. When the orientation treatment is performed, the molecules 310 of the reverse dispersion liquid crystalline compound located at the air interface 300U of the layer 300 tend to be oriented such that the inclination angle of the molecules 310 becomes larger. Furthermore, in accordance with the orientation of the molecules 310 of the inverse dispersive liquid crystalline compound located at the air interface 300U, the molecules of the inverse dispersive liquid crystalline compound 320 located at the depth thereof will also be oriented in such a manner that the inclination angle of the molecules 320 becomes larger. Here, the so-called “deep place” refers to a direction away from the air interface 300U in the thickness direction of the layer 300. In addition, in accordance with the orientation of the molecules 320 of the reverse dispersion liquid crystalline compound, the molecules 330 of the reverse dispersion liquid crystalline compound located deeper will also be oriented such that the inclination angle of the molecules 330 becomes larger.

However, according to the orientation, the inclination angles of the molecules 310, 320, and 330 become larger, and the further away from the air interface, the 300U becomes weaker. As such, if the layer body 300 is too thick, although the inclination angle of the molecule 310 can be increased in the adjacent portion of the air interface 300U, the inclination angle cannot be increased in other portions. As a result, a large inclination angle cannot be obtained as a whole of the layer body 300, and thus a large substantially maximum inclination angle cannot be obtained.

In contrast, in the liquid crystal alignment layer according to the embodiment of the present invention, the upper limit of the thickness T is appropriately set. Thereby, as a whole, the molecules 310, 320, and 330 of the reverse dispersion liquid crystalline compound can be obtained with a large tilt angle, thereby making it possible to increase the substantial maximum tilt angle of the molecules of the reverse dispersion liquid crystal compound.

In addition, when performing the above-mentioned orientation treatment, generally, volatile components such as solvents contained in the layer body 300 evaporate from the air interface 300U as shown by the arrow A300. Therefore, in the layer body 300, convection is generated accompanying the movement of volatile components. If the convection is large, the orientations of the molecules 310, 320, and 330 of the reverse dispersion liquid crystalline compound will be disturbed to cause orientation defects.

On the other hand, in a liquid crystal alignment layer related to one embodiment of the present invention, a fluorine-based surfactant 340 is used to suppress alignment defects. In general, the surfactant tends to aggregate at the interface, and therefore, a fluorine-based surfactant 340 is present at the air interface 300U of the layer body 300. If the fluorine-based surfactant 340 is located at the air interface 300U, the fluorine-based surfactant 340 can suppress the evaporation of volatile components. Accordingly, since the convection in the layer body 300 is suppressed, the occurrence of orientation defects can be suppressed.

However, the thicker the layer body 300 is, the more the volatile components per unit area are evaporated, the larger the convection current in the layer body 300 is. Therefore, if the amount of the fluorine-based surfactant 340 at the air interface 300U is smaller than the thickness of the layer body 300, it is difficult to suppress the occurrence of alignment defects.

On the other hand, in the liquid crystal alignment layer related to one embodiment of the present invention, the amount of the fluorine-based surfactant 340 at the air interface 300U is sufficiently greater than the thickness T to suppress alignment defects. The air interface 300U of the layer body 300 of the alignment layer composition corresponds to a specific surface of the liquid crystal alignment layer. The amount of the fluorine-based surfactant 340 at the air interface 300U of the layer body 300 of the alignment layer composition corresponds to the amount of fluorine atoms on a specific surface of the liquid crystal alignment layer. Accordingly, the amount of the fluorine-based surfactant 340 at the air interface 300U is sufficiently larger than the thickness of the layer body 300 of the alignment layer composition, and the amount of fluorine atoms M _F on the surface of the specific surface of the liquid crystal alignment layer can be appropriately set through [ The lower limit of the ratio M _F / T of the mole%] to the thickness T [μm] of the layer body.

In addition, as described above, the molecules 310 of the reverse dispersion liquid crystalline compound tend to be aligned at the air interface 300U of the layer body 300 with a larger tilt angle. Accordingly, if the air interface 300U is covered with an excessive amount of the fluorine-based surfactant 340, it is difficult to increase the tilt angle of the molecule 310 of the reverse dispersion liquid crystalline compound.

In contrast, in the liquid crystal alignment layer related to one embodiment of the present invention, the amount of the fluorine-based surfactant 340 at the air interface 300U is adjusted so that the thickness T does not become excessive, so as to obtain a large substantial maximum. Tilt angle. In this way, the amount of the fluorine-based surfactant 340 at the air interface 300U is not more than the thickness of the layer body 300 of the alignment layer composition, and the amount of fluorine atoms M _{F on} the specific surface of the liquid crystal alignment layer can be appropriately set through the [Mole It is expressed by the upper limit of the ratio M _F / T of the ratio [%] to the thickness T [μm] of the layer.

The mechanism inferred by the inventors is the above. However, the technical scope of the present invention is not limited to the mechanism described above.

The liquid crystal alignment layer usually has a good surface state. According to this, the unevenness of the thickness of the liquid crystal alignment layer is generally small, so that the unevenness of the in-plane retardation can be reduced.

(1.6. Manufacturing method of liquid crystal alignment layer)

The manufacturing method of a liquid crystal aligning layer is arbitrary as long as the desired liquid crystal aligning layer can be obtained. In one embodiment, the liquid crystal alignment layer can be manufactured by a manufacturing method including the following steps:
(I) a step of forming a layered body of the alignment layer composition;
(Ii) a step of orienting the reverse dispersion liquid crystalline compound contained in the layer of the alignment layer composition; and (iii) a step of curing the layer of the alignment layer composition to obtain a liquid crystal alignment layer.

In step (i), a layered body of the alignment layer composition is usually formed on a suitable support surface. As the supporting surface, an arbitrary surface of a layer body capable of supporting the alignment layer composition may be used. As this support surface, a flat surface without a concave portion and a convex portion is preferably used from the viewpoint of optimizing the surface state of the liquid crystal alignment layer. From the viewpoint of improving the productivity of the liquid crystal alignment layer, as the support surface, a surface of a long substrate is preferably used. Here, the so-called “long strip” refers to a shape having a length of 5 times or more with respect to the width, and preferably a length of 10 times or more, and specifically refers to a roll that can be rolled or stored. The length of the shape of the film.

As the substrate, a resin film or a glass plate is usually used. In particular, when performing an orientation treatment at a high temperature, it is better to select a substrate that can withstand this temperature. As the resin, a thermoplastic resin is usually used. Among these, from the viewpoints of high orientation restraining force, high mechanical strength, and low cost, as the resin, a resin having a positive intrinsic birefringence value is preferred. Furthermore, in terms of excellent transparency, low hygroscopicity, dimensional stability, and light weight, a resin containing an alicyclic structure-containing polymer such as a norbornene-based resin is preferably used. To give a suitable example of the resin contained in the base material under a trade name, "ZEONOR" manufactured by Japan's Rui On Co., Ltd. can be cited as the norylene resin.

In order to promote the orientation of the reverse dispersion liquid crystalline compound in the layered body of the alignment layer composition on the surface of the substrate serving as the support surface, it is preferable to apply a treatment for imparting an alignment restricting force. The term "orientation limiting force" refers to a "plane property" that orients a liquid crystal compound such as a reverse dispersion liquid crystal compound contained in an alignment layer composition. Examples of the process for applying an orientation restricting force to the support surface include a light orientation process, a rubbing process, an ion beam orientation process, and an extension process.

In the step (i) of forming a layered body of the alignment layer composition, the alignment layer composition is usually prepared in a fluid state. Therefore, the support layer is usually coated with an alignment layer composition to form a layered body of the alignment layer composition. Examples of the method for applying the alignment layer composition include a curtain coating method, an extrusion coating method, a roll coating method, a spin coating method, a dip coating method, a bar coating method, a spray coating method, a slant plate coating method, a printing coating method, Gravure coating method, die coating method, gap coating method and dipping method.

After the step (i) of forming a layered body of the alignment layer composition, a step (ii) of orienting the reverse dispersion liquid crystalline compound contained in the layered body of the alignment layer composition is performed. When performing orientation, the layered body of the orientation layer composition is usually maintained for as long as specified at the specified temperature. Thereby, in the layered body of the alignment layer composition, liquid crystal compounds such as a reverse dispersion liquid crystal compound are aligned.

Generally, in the in-plane direction, the reverse-dispersion liquid crystalline compound is aligned in a direction corresponding to the orientation restricting force of the support surface. In addition, if the composition of the alignment layer contains an oblique action component, the reverse dispersion liquid crystalline compound is oriented in such a way that at least a part of it is greatly inclined with respect to the plane of the layer body (that is, relative to the in-plane direction) in the thickness direction. The substantial maximum tilt angle of the molecules of the reverse dispersion liquid crystal compound contained in the layer of the large alignment layer composition.

In addition, in the step (ii), it is preferable to adjust the operation or conditions so that a liquid crystal alignment layer having a substantially maximum inclination angle of the molecules of the reverse dispersion liquid crystalline compound can be obtained.

For example, step (ii) is preferably performed in such a manner that the temperature conditions of the layered body of the alignment layer composition satisfy the specified requirements. Specifically, the temperature condition of the layered body of the alignment layer composition in the step (ii) is preferably performed in the same manner as the temperature condition that the viscosity of the residual component of the test composition is usually 800 cP or less. The aforementioned so-called test composition is a composition having a composition in which a polymerization initiator has been excluded from the alignment layer composition. The residual component viscosity of the test composition refers to the viscosity of the residual component of the test composition under the same temperature condition as that of the layer body of the alignment layer composition in the step (ii). In addition, the residual component of the test composition is a component that remains without being vaporized under the same temperature condition as the layer body of the alignment layer composition in the step (ii) among the components included in the test composition. By performing the step (ii) by satisfying such requirements, it is possible to increase the substantial maximum tilt angle of the molecules of the reverse dispersion liquid crystalline compound contained in the liquid crystal alignment layer.

This is explained in more detail. When the step (ii) of orienting the reverse dispersion liquid crystalline compound is performed so as to satisfy the aforementioned requirements, the step (ii) is to adjust the layer body of the alignment layer composition to remain with the test composition. The temperature conditions under which the component viscosity falls within the specified range are the same temperature conditions. The specific range of the viscosity of the residual component is generally 800 cP (centipoise) or less, preferably 600 cP or less, more preferably 400 cP or less, and even more preferably 200 cP or less. By using the same temperature conditions as the temperature conditions at which the viscosity of the remaining components of the test composition becomes lower, the liquid crystal compounds in the layer body of the alignment layer composition are aligned, thereby increasing the reverse dispersion liquid crystal contained in the liquid crystal alignment layer. Substantial maximum tilt angle of the molecule of the sex compound. From the viewpoint of obtaining a liquid crystal alignment layer having a desired thickness, the lower limit of the viscosity of the residual component is preferably 5 cP or more, and more preferably 10 cP or more.

Under the same temperature conditions as the layered body of the alignment layer composition in step (ii), the residual component viscosity of the test composition can be measured by the following method.

A test composition having a polymerization initiator excluded from the alignment layer composition was prepared. This test composition was concentrated under reduced pressure on a rotary evaporator to remove the solvent, and a residual component was obtained. The viscosity of the residual component is measured in advance while changing the measurement temperature to obtain information about the measurement temperature and the viscosity at the measurement temperature. This information is appropriately referred to as "temperature-viscosity information" hereinafter. From this "temperature-viscosity information", the viscosity at the temperature of the layered body of the alignment layer composition in step (ii) is understood as the viscosity of the residual component.

Examples of a method for reducing the viscosity of the residual component of the test composition to the above-mentioned range under the same temperature conditions as the layered body of the alignment layer composition in step (ii) include the following methods (A) and (B) .
(A) The temperature of the layer body of the alignment layer composition in the step (ii) of orienting the reverse dispersion liquid crystalline compound is appropriately adjusted. In this method, it is usually adjusted by reducing the viscosity of the residual component of the test composition under the same temperature condition by making the temperature of the layer of the alignment layer composition high enough to make it into the above range. .
(B) Moderately adjust the composition of the alignment layer composition. In this method, it is usually adjusted by reducing the residual components of the test composition containing the additive by combining an appropriate type and amount of the additive to the reverse dispersion liquid crystalline compound as a component included in the alignment layer composition Viscosity to make it into the above range.

Regarding the adjustment of the temperature conditions of the layered body of the alignment layer composition in the step (ii), reference may be made to the descriptions of International Patent Publication No. 2018/173773 and Japanese Patent Application No. 2017-060159.

In addition, for example, when an alignment layer composition containing a liquid crystal compound having a magnetic field responsiveness is used, it is preferable to perform step (ii) in a state where a magnetic field is applied to the layer body of the alignment layer composition. This makes it possible to increase the substantial maximum tilt angle of the molecules of the reverse dispersion liquid crystalline compound contained in the liquid crystal alignment layer.

The direction of the magnetic field applied to the layer of the alignment layer composition is generally a direction that is not perpendicular to the thickness direction of the layer of the alignment layer composition, and preferably a direction parallel to the thickness direction of the layer of the alignment layer composition. By applying a magnetic field in this direction, the substantial maximum tilt angle of the molecules of the reverse-dispersion liquid crystal compound contained in the liquid crystal alignment layer can be effectively increased.

The magnetic flux density of the magnetic field applied to the layer body of the alignment layer composition is preferably 0.2 Tesla or more, more preferably 0.5 Tesla or more, and particularly preferably 0.8 Tesla or more. By applying a magnetic field of this magnitude, the substantial maximum tilt angle of the molecules of the reverse-dispersing liquid crystal compound contained in the liquid crystal alignment layer can be effectively increased. The upper limit of the magnetic flux density of the magnetic field is not limited, and is set to, for example, 20.0 Tesla or less. Regarding the applied magnetic field, reference can be made to the descriptions in Japanese Patent Laid-Open No. 2018-163218 and Japanese Patent Application No. 2017-059327.

The specific temperature at the time of the orientation treatment is appropriately set in a range above the liquid crystal transition temperature of the reverse dispersion liquid crystalline compound, and a temperature below the glass transition temperature of the resin contained in the substrate is preferred. This can suppress the occurrence of strain on the substrate caused by the alignment treatment.

The step (ii) of orienting the reverse dispersion liquid crystalline compound is usually performed in an oven. At this time, the set temperature of the oven and the temperature of the layer body of the alignment layer composition placed in the oven may be different. In this case, it is better to measure and record in advance: at a plurality of oven set temperatures, the temperature of the layer of the alignment layer composition placed in the oven at this set temperature is better. Hereinafter, the information of the recorded set temperature of the oven and the temperature of the layer of the alignment layer composition placed in the oven at the set temperature is appropriately referred to as "set temperature-layer temperature information". If this "set temperature-layer body temperature information" is used, the temperature of the layer body of the alignment layer composition placed in the oven can be easily known from the oven set temperature.

In the step (ii) of orienting the reverse-dispersion liquid crystalline compound, the temperature of the layer of the alignment layer composition is maintained at the aforementioned temperature for a period of time that can be arbitrarily set within a range in which a desired liquid crystal alignment layer can be obtained, for example: 30 seconds to 5 minutes.

After the step (ii) of orienting the reverse dispersion liquid crystalline compound, a step (iii) of curing the layered body of the alignment layer composition to obtain a liquid crystal alignment layer is performed. In this step (iii), a part or the whole of a liquid crystal compound such as a reverse dispersion liquid crystal compound is usually polymerized to cure the layer body of the alignment layer composition. During the polymerization, the liquid crystal compound is usually polymerized directly while maintaining the orientation of its molecules. Therefore, by the aforementioned polymerization, the alignment state of the liquid crystal compound contained in the alignment layer composition before the polymerization is fixed.

As the polymerization method, a method suitable for selecting the properties of the components contained in the alignment layer composition may be selected. Examples of the polymerization method include a method of irradiating an active energy ray and a thermal polymerization method. Among them, since the polymerization reaction can be performed at room temperature without heating, a method of irradiating active energy rays is preferable. Here, the active energy rays to be irradiated may include light rays such as visible light, ultraviolet rays and infrared rays, and arbitrary energy rays such as electron beams.

Among them, a method of irradiating light such as ultraviolet rays is preferable for easy operation. The temperature at the time of ultraviolet irradiation is preferably below the glass transition temperature of the substrate, more preferably 150 ° C or lower, more preferably 100 ° C or lower, and even more preferably 80 ° C or lower. The lower limit of the temperature at the time of ultraviolet irradiation is set to 15 ° C or higher. The ultraviolet irradiation intensity is preferably 0.1 mW / cm ² or more, more preferably 0.5 mW / cm ² or more, and more preferably 10,000 mW / cm ² or less, more preferably 5,000 mW / cm ² or less, and 1000 mW / cm ² or less is more preferred, at 600 mW / cm ² or less is preferred. The amount of ultraviolet radiation is preferably 0.1 mJ / cm ² or more, more preferably 0.5 mJ / cm ² or more, and more preferably 10,000 mJ / cm ² or less, and more preferably 5,000 mJ / cm ² or less.

According to the above manufacturing method, a liquid crystal alignment layer can be manufactured. In this manufacturing method, a liquid crystal alignment layer formed on a supporting surface of a substrate is usually obtained.

The manufacturing method of the said liquid crystal aligning layer may further contain arbitrary processes and combine them in said process (i)-process (iii).

For example, the manufacturing method of a liquid crystal aligning layer may include the process of peeling a liquid crystal aligning layer from a support surface.

According to the aforementioned general manufacturing method, a long liquid crystal alignment layer can be obtained by using a long substrate. Such a long liquid crystal alignment layer can be continuously manufactured and has excellent productivity. Generally, a film including a long liquid crystal alignment layer is rolled up, stored and transported in a roll state.

[2. Optical film]

(2.1. Overview of Optical Film)

As shown in FIG. 2, an optical film 200 according to an embodiment of the present invention includes a liquid crystal alignment layer 100 and a liquid crystal tilting layer 210 directly connected to a specific surface 100U of the liquid crystal alignment layer 100. Therefore, the optical film 200 includes a composite liquid crystal layer 220 including a liquid crystal alignment layer 100 and a liquid crystal inclined layer 210. The so-called "directly" contacting another layer body with another layer body means that there is no other layer body between these two layer bodies.

The liquid crystal tilt layer 210 is formed of a cured product of a tilt layer composition containing a reverse dispersion liquid crystalline compound. Since it is formed of a cured product of the composition of the inclined layer, the liquid crystal inclined layer 210 contains molecules of a reverse dispersion liquid crystal compound. The molecules of the reverse dispersion liquid crystalline compound contained in the liquid crystal inclined layer 210 are usually fixed in the alignment state. Similar to the liquid crystal alignment layer 100, the polymerized reverse dispersion liquid crystal compound is included in the term "reverse dispersion liquid crystal compound included in the liquid crystal inclined layer".

Molecules of at least a part of the reverse dispersion liquid crystalline compound included in the liquid crystal inclined layer 210 are inclined with respect to a layer body plane (that is, with respect to an in-plane direction) of the liquid crystal inclined layer 210. Here, the specific surface 100U of the liquid crystal alignment layer 100 has an alignment restricting force that orients the molecules of the reverse dispersion liquid crystalline compound included in the liquid crystal inclined layer 210 formed on the specific surface 100U. This orientation limiting force causes the molecules of the reverse-dispersive liquid crystal compound contained in the liquid crystal tilt layer 210 to be in the same direction as the orientation of the molecules of the reverse-dispersed liquid crystal compound contained in the liquid crystal alignment layer 100 in the in-plane direction. Directional. In addition, the aforementioned orientation restricting force orients the molecules of the inverse dispersion liquid crystalline compound included in the liquid crystal inclined layer 210 in the thickness direction so that the inclination angle of the molecules becomes large. Accordingly, the liquid crystal alignment layer 100 can function as an alignment film that increases the inclination angle of the molecules of the reverse dispersion liquid crystalline compound included in the liquid crystal inclined layer 210. Therefore, the tilt angle of the molecules of the reverse-dispersion liquid crystal compound contained in the liquid crystal tilt layer 210 can be increased by the action of the liquid crystal alignment layer 100. This makes it possible to increase the tilt angle of the molecules of the reverse dispersion liquid crystalline compound in the entire composite liquid crystal layer 220 including the liquid crystal alignment layer 100 and the liquid crystal tilt layer 210. In addition, by increasing the inclination angle of the molecules of the reverse dispersion liquid crystalline compound in the entire composite liquid crystal layer 220 as described above, when the optical film 200 including the composite liquid crystal layer 220 is provided on a reflection suppressing film, it can be appropriately performed in Adjustment of birefringence in the thickness direction. Therefore, according to this optical film 200, reflection can be effectively suppressed in the oblique direction of the display surface, and thus the viewing angle characteristics can be improved.

In addition, since the liquid crystal inclined layer 210 contains a reverse dispersion liquid crystalline compound, the liquid crystal inclined layer 210 has an in-plane retardation of reverse wavelength dispersion. Therefore, both the liquid crystal alignment layer 100 and the liquid crystal inclined layer 210 have in-plane retardation with inverse wavelength dispersion. Therefore, the optical film 200 including these layers 100 and 210 may have in-plane retardation with inverse wavelength dispersion.

The orientation state of the reverse-dispersion liquid crystal compound in the liquid crystal tilt layer 210 is affected by the orientation state of the liquid crystal alignment layer 100 that can function as an alignment film, as described above. Accordingly, by suppressing the occurrence of alignment defects in the liquid crystal alignment layer 100, the occurrence of alignment defects can also be suppressed in the liquid crystal tilt layer 210.

Therefore, the optical film 200 included in the combination of the liquid crystal alignment layer 100 and the liquid crystal inclined layer 210 has an in-plane retardation of reverse wavelength dispersion, can suppress the occurrence of alignment defects, and has excellent viewing angle characteristics.

Moreover, in the optical film 200, the surface states of the liquid crystal inclined layer 210 and the composite liquid crystal layer 220 can generally be optimized.

(2.2. LCD tilt layer)

The liquid crystal inclined layer is a layer body formed of a cured product of an inclined layer composition containing a reverse dispersion liquid crystalline compound. As the reverse-dispersive liquid crystal compound contained in the inclined layer composition, any range of reverse-dispersive liquid crystal compounds can be selected and used from the range of the reverse-dispersive liquid crystal compound contained in the alignment layer composition. Thereby, the same advantages as those obtainable in the alignment layer composition and the liquid crystal alignment layer can also be obtained in the tilted layer composition and the liquid crystal tilted layer. The reverse-dispersive liquid crystal compound contained in the oblique layer composition may be the same as or different from the reverse-dispersive liquid crystal compound contained in the alignment layer composition. In addition, as the reverse-dispersion liquid crystal compound contained in the inclined layer composition, one kind may be used alone, or two or more kinds may be used in combination at any ratio.

Furthermore, the oblique layer composition may optionally include any combination of components in a reverse dispersion liquid crystal compound. An arbitrary component may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios. As an arbitrary component, for example, components other than the reverse dispersion liquid crystal compound contained in the alignment layer composition can be used in the range of the amount of the aforementioned components in the alignment layer composition. Thereby, the same advantages as those obtainable in the alignment layer composition and the liquid crystal alignment layer can also be obtained in the tilted layer composition and the liquid crystal tilted layer.

The composition of the inclined layer may be different from the composition of the alignment layer, or may be the same.

The curing of the inclined layer composition is the same as the curing of the alignment layer composition, and is usually achieved by polymerizing a polymerizable compound contained in the inclined layer composition. Therefore, the liquid crystal tilting layer usually contains a part or all of a polymer of a component contained in the tilting layer composition. For example, when the reverse-dispersive liquid crystalline compound is polymerizable, since the reverse-dispersive liquid crystalline compound is polymerized, the liquid crystal inclined layer can be polymerized by including the reverse-dispersive liquid crystalline compound that is directly polymerized while maintaining the orientation state before polymerization. Layer of things.

In the cured product of the inclined layer composition, since the fluidity before curing is lost, the orientation state of the reverse dispersion liquid crystalline compound is usually directly fixed in the orientation state before curing. In addition, the molecules of the reverse-dispersing liquid crystal compound contained in the liquid crystal inclined layer are greatly inclined with respect to the plane of the layer body of the liquid crystal inclined layer (that is, with respect to the in-plane direction) through the action of the liquid crystal alignment layer. Therefore, the substantial maximum tilt angle of the molecules of the reverse dispersion liquid crystalline compound contained in the liquid crystal tilt layer can be increased. In a liquid crystal tilted layer, this substantial maximum tilt angle indicates that the reverse dispersion is assumed when the tilt angle of a molecule on the side of the liquid crystal alignment layer is 0 ° and the tilt angle of the molecule changes in a certain ratio in the thickness direction. The maximum value of the tilt angle of the molecules of the liquid crystal compound. This substantial maximum tilt angle is an index indicating the magnitude of the tilt angle of the molecules of the reverse dispersion liquid crystalline compound contained in the liquid crystal tilt layer. In general, the more the liquid crystal inclined layer with the substantially largest maximum inclination angle is, the more inclined the inclination angle as the whole of the molecules of the reverse-dispersing liquid crystal compound contained in the liquid crystal inclined layer is. Through the action of the liquid crystal alignment layer, the substantial maximum tilt angle of the molecules of the reverse dispersion liquid crystalline compound contained in the liquid crystal tilting layer is usually larger than the substantial maximum tilt angle of the molecules of the reverse dispersion liquid crystal compound contained in the liquid crystal alignment layer. .

The substantial maximum tilt angle of the molecules of the reverse dispersion liquid crystalline compound contained in the liquid crystal tilting layer is preferably 45 ° or more, more preferably 50 ° or more, particularly preferably 57 ° or more, and most preferably 85 ° or less. When the substantially maximum tilt angle of the molecules of the reverse-dispersing liquid crystal compound contained in the liquid crystal tilt layer is in the aforementioned range, particularly excellent viewing angle characteristics can be obtained.

The substantial maximum tilt angle of the molecules of the reverse dispersion liquid crystalline compound contained in the liquid crystal tilt layer can be measured by the following method.

The substantial maximum tilt angle of the molecules of the reverse dispersion liquid crystalline compound contained in the liquid crystal alignment layer is measured. In addition, a substantial maximum inclination angle of a molecule of the reverse dispersion liquid crystalline compound included in the entire composite liquid crystal layer including the liquid crystal alignment layer and the liquid crystal inclined layer is measured. Then, using these measured maximum inclination angles and the thickness of the liquid crystal alignment layer and the liquid crystal inclination layer, the substantial maximum inclination angle of the molecules of the reverse dispersion liquid crystalline compound contained in the liquid crystal inclination layer can be calculated.

In addition, the difference between the substantial maximum tilt angle of the molecules of the reverse dispersion liquid crystalline compound contained in the liquid crystal alignment layer and the substantial maximum tilt angle of the molecules of the reverse dispersion liquid crystalline compound contained in the liquid crystal tilt layer is preferably 5 ° or more. 8 ° or more is preferable, 10 ° or more is particularly preferable, 59 ° or less is preferable, 57 ° or less is preferable, and 55 ° or less is more preferable. When the difference between the substantially maximum tilt angles is in the aforementioned range, particularly excellent viewing angle characteristics can be obtained.

The orientation direction of the molecules of the reverse dispersion liquid crystalline compound in the in-plane direction of the liquid crystal inclined layer is generally the same as the orientation direction of the molecules of the reverse dispersion liquid crystalline compound in the in-plane direction of the liquid crystal alignment layer.

In addition, since alignment defects can be suppressed in the liquid crystal alignment layer, the occurrence of alignment defects can also be suppressed in the liquid crystal tilt layer formed on the liquid crystal alignment layer.

In addition, the liquid crystal inclined layer usually has a good surface state.

The thickness of the liquid crystal inclined layer is not particularly limited. It is preferably 0.3 μm or more, more preferably 0.5 μm or more, and more preferably 10.0 μm or less, more preferably 7.5 μm or less, and more preferably 5.0 μm or less. It is particularly preferable that it is 3.0 μm or less.

(2.3. Composite liquid crystal layer)

The optical film includes a liquid crystal alignment layer formed of a cured product of an alignment layer composition of a liquid crystal composition containing a reverse dispersion liquid crystal compound, and an optical film composition of an inclined layer composition of a liquid crystal composition containing a reverse dispersion liquid crystal compound. A liquid crystal inclined layer formed by a cured product. According to this, the optical film includes a composite liquid crystal layer including a liquid crystal alignment layer and a liquid crystal inclined layer as a liquid crystal cured layer having a multilayer structure formed of a cured product of a liquid crystal composition containing a reverse dispersion liquid crystal compound.

From the fact that the liquid crystal alignment layer and the liquid crystal tilting layer are included, it is known that the molecules of at least a part of the reverse-dispersive liquid crystal compound contained in the composite liquid crystal layer are inclined with respect to the layer body plane (that is, with respect to the in-plane direction) of the composite liquid crystal layer. The fact that at least a part of the molecules of the reverse-dispersive liquid crystalline compound contained in the composite liquid crystal layer is inclined with respect to the plane of the layer body (that is, with respect to the in-plane direction) can be performed by the same method as described in the item of the liquid crystal alignment layer. Method to confirm. In addition, in a composite liquid crystal layer including a liquid crystal alignment layer and a liquid crystal inclined layer, the inclination angle of the molecules of the reverse dispersion liquid crystalline compound included in the composite liquid crystal layer can be increased as a whole. Therefore, the substantial maximum tilt angle of the molecules of the reverse dispersion liquid crystalline compound contained in the composite liquid crystal layer can be increased.

In the composite liquid crystal layer, the substantial maximum tilt angle indicates that the reverse dispersion liquid crystal is assumed to assume that the tilt angle of the molecule on the side of the liquid crystal alignment layer is 0 ° and the tilt angle of the molecule changes at a certain ratio in the thickness direction. The maximum inclination angle of the molecule of a sex compound. This substantial maximum tilt angle is an indicator of the magnitude of the tilt angle of the molecules of the reverse dispersion liquid crystalline compound contained in the composite liquid crystal layer. In general, the more the composite liquid crystal layer having a substantially maximum tilt angle is, the larger the tilt angle as a whole of the molecules of the reverse dispersion liquid crystal compound contained in the composite liquid crystal layer tends to be. Accordingly, by increasing the substantial maximum tilt angle of the molecules of the reverse-dispersive liquid crystal compound contained in the composite liquid crystal layer, the birefringence of the composite liquid crystal layer in the thickness direction can be increased. In addition, by increasing the birefringence of the composite liquid crystal layer in the thickness direction, the birefringence in the thickness direction of the optical film can be appropriately adjusted. Therefore, in a case where the optical film is provided on a polarizing plate as a reflection suppressing film, excellent viewing angle characteristics that can effectively suppress reflection in the oblique direction of the display surface can be obtained.

The substantial maximum tilt angle of the molecules of the reverse dispersion liquid crystalline compound contained in the composite liquid crystal layer is generally larger than the substantial maximum tilt angle of the molecules of the reverse dispersion liquid crystalline compound contained in the liquid crystal alignment layer. From the viewpoint of achieving excellent viewing angle characteristics, the substantial maximum tilt angle of the molecules of the reverse dispersion liquid crystalline compound contained in the composite liquid crystal layer is preferably 40 ° or more, more preferably 46 ° or more, and particularly 56 ° or more It is preferably 85 ° or less, more preferably 83 ° or less, and even more preferably 80 ° or less. If the substantial maximum tilt angle of the molecules of the reverse dispersion liquid crystalline compound contained in the composite liquid crystal layer is in the aforementioned range, the birefringence in the thickness direction of the optical film can be adjusted appropriately. Therefore, by combining this optical film with a linear polarizer, it is possible to realize a polarizing plate that can achieve high viewing angle characteristics when installed on an organic EL display panel.

The substantial maximum tilt angle of the molecules of the reverse-dispersion liquid crystal compound contained in the composite liquid crystal layer can be measured by a measurement method described in Examples described later. According to the measurement methods described in the examples described later, even when the composite liquid crystal layer includes a liquid crystal compound other than the reverse dispersion liquid crystal compound, the substantial maximum tilt angle of the molecules of the reverse dispersion liquid crystal compound can be measured with energy.

Since the composite liquid crystal layer includes a liquid crystal alignment layer containing a liquid crystal compound having a reverse dispersion and a liquid crystal inclined layer, it can have an in-plane retardation with a reverse wavelength dispersion property. Accordingly, the in-plane retardation of the composite liquid crystal layer usually satisfies the aforementioned formula (N3), and preferably satisfies the aforementioned formula (N4).

In the liquid crystal alignment layer, as described above, the occurrence of alignment defects is suppressed. In addition, as described later, the liquid crystal alignment layer has a high affinity for the composition of the inclined layer. Therefore, the composition of the inclined layer is compatible with the liquid crystal alignment layer, and the alignment of the molecules is not easily confused. Accordingly, the orientation state can be made uniform in the in-plane direction in the inclined layer composition. Thereby, the liquid crystal inclined layer provided on the liquid crystal alignment layer can also suppress the occurrence of alignment defects. Therefore, the entire composite liquid crystal layer including the liquid crystal alignment layer and the liquid crystal inclined layer can also suppress the occurrence of alignment defects.

In the in-plane direction, the molecules of the reverse-dispersive liquid crystal compound contained in the composite liquid crystal layer are aligned in the same in-plane direction as the orientation direction of the molecules of the reverse-dispersive liquid crystal compound contained in the liquid crystal alignment layer. Therefore, the in-plane slow axis of the composite liquid crystal layer is generally parallel to the in-plane slow axis of the liquid crystal alignment layer.

The composite liquid crystal layer usually has a good surface state. According to this, the unevenness of the thickness of the composite liquid crystal layer is generally small, so the unevenness of the in-plane retardation is small.

The thickness of the composite liquid crystal layer is preferably 0.5 μm or more, more preferably 1.0 μm or more, and more preferably 12.5 μm or less, more preferably less than 9.5 μm, and more preferably 6.8.0 μm or less. It is preferably 6.6 μm or less, and particularly preferably 4.0 μm or less. Since the thickness of the composite liquid crystal layer is in the aforementioned range, characteristics such as in-plane retardation can be easily adjusted to a desired range. In addition, the composite liquid crystal layer having such a thickness is thinner than a conventional retardation film used in a reflection suppressing film for an organic EL display panel, and thus can contribute to a reduction in thickness of the organic EL display panel.

Incidentally, the composite liquid crystal layer may be a liquid crystal cured layer having a two-layer structure including only one liquid crystal alignment layer and one liquid crystal inclined layer, but may also be a liquid crystal cured layer including three or more layers. For example, when a liquid crystal composition containing a fluorine-based surfactant is used as the tilt layer composition in the same manner as the alignment layer composition, a thickness T and a ratio M having a range required by the liquid crystal alignment layer may be obtained in some cases. The layer of _F / T is used as the liquid crystal tilting layer. This liquid crystal inclined layer can function as a liquid crystal alignment layer. Therefore, by forming another liquid crystal inclined layer on this liquid crystal inclined layer, a composite liquid crystal layer including a layer body of three or more layers can be obtained.

In the composite liquid crystal layer, the liquid crystal alignment layer and the liquid crystal inclined layer are usually distinguished by the following method.

The composite liquid crystal layer was embedded with epoxy resin to obtain a test piece. Using a slicer, slice this test piece in parallel along the thickness direction of the composite liquid crystal layer to obtain an observation sample. At this time, the slicing is performed so that the in-plane slow axis direction and the cross section of the composite liquid crystal layer become parallel. Then, a cross section showing the section was observed using a polarizing microscope. This observation is performed by inserting a wavelength plate as a test plate between the observation sample and the objective lens of the polarizing microscope, and performing the method such that an image showing a color corresponding to the retardation of the observation sample is seen. At this time, a portion having a different color can be distinguished as a boundary between the liquid crystal alignment layer and the liquid crystal inclined layer.

(2.4. Any layer)

The optical film may be a film including only a liquid crystal alignment layer and a liquid crystal inclined layer, or may be a film including an arbitrary layer combination of a liquid crystal alignment layer and a liquid crystal inclined layer. Examples of the arbitrary layer body include: a base material used for manufacturing a liquid crystal alignment layer; a retardation film; a bonding agent layer for bonding with other components; a base pad layer for optimizing the smoothness of the film; and an impact-resistant polymethyl Hard coatings such as acrylic resin layers; anti-reflection layers; antifouling layers; etc.

(2.5. Characteristics of optical film)

Since the optical film includes a composite liquid crystal layer including a liquid crystal alignment layer and a liquid crystal inclined layer, the birefringence in the thickness direction of the optical film can be appropriately adjusted. Therefore, in a case where the optical film is provided on a polarizing plate as a reflection suppressing film, excellent viewing angle characteristics that can effectively suppress reflection in the oblique direction of the display surface can be obtained.

From the viewpoint of achieving excellent viewing angle characteristics, the average retardation ratio R (± 50 °) / R (0 °) of the optical film is preferably 0.90 or more, more preferably 0.92 or more, and even more preferably 0.93 or more. In addition, it is preferably 1.15 or less, more preferably 1.12 or less, and even more preferably 1.10 or less. Here, the so-called R (± 50 °) means that in the measurement direction perpendicular to the fast axis direction in the plane of the optical film, the optical film measured at an incident angle θ of −50 ° and + 50 ° is measured. The average of the retardation R (-50 °) and R (+ 50 °). In addition, R (0 °) represents a retardation of an optical film at an incident angle of 0 °.

Generally, the external light incident on the display surface of the image display device at the incident angle "+ ϕ" is reflected at the exit angle "-ϕ". Therefore, in the case where the reflection suppressing film provided on the display surface includes an optical film, in the oblique direction of the display surface, external light will be included in the outbound at the incident angle "+ ϕ" and the return at the exit angle "-ϕ" The distance through the optical film. From the viewpoint of effectively suppressing the reflection of light passing through this distance, the retardation ratio R (± 50 °) / R (0 °) of the optical film is preferably close to 1.00. Since the retardation ratio R (± 50 °) / R (0 °) of the optical film is in the aforementioned range close to 1.00, a polarizing plate including the optical film can be used to effectively suppress the reflection of external light in the oblique direction. Specifically, during the time when the external light passes through the optical film twice when it is incident and when it is reflected, the polarization state is appropriately changed, thereby making it possible to effectively shield the linear polarizer using the polarizing plate. Therefore, when such an optical film is used in combination with a linear polarizer to obtain a polarizing plate, it can exert the reflection suppressing ability of the polarizing plate over a wide range of incident angles, and thus can obtain particularly excellent viewing angle characteristics.

Since an optical film includes a composite liquid crystal layer including a liquid crystal alignment layer and a liquid crystal inclined layer, it can have in-plane retardation with reverse wavelength dispersion. Accordingly, the in-plane retardation of the optical film usually satisfies the aforementioned formula (N3), and preferably satisfies the aforementioned formula (N4). Such an optical film having in-plane retardation with inverse wavelength dispersion can exert its optical function in a wide wavelength range. Accordingly, when this optical film is used in a polarizing plate as a reflection suppression film, reflection can be suppressed in a wide wavelength range.

The specific in-plane retardation range of the optical film can be arbitrarily set according to the application of the optical film. In particular, in order to obtain a polarizing plate as a reflection suppressing film for an organic EL display panel in combination with a linear polarizer, it is desirable that the optical film has an in-plane retardation that can function as a 1/4 wavelength plate. Here, the so-called in-plane retardation that can function as a 1/4 wavelength plate, specifically, at a measurement wavelength of 590 nm, preferably 100 nm or more, more preferably 110 nm or more, and 120 nm or more More preferably, it is preferably 180 nm or less, more preferably 170 nm or less, and even more preferably 160 nm or less.

In the composite liquid crystal layer included in the optical film, as described above, the occurrence of alignment defects is suppressed. According to this, if this optical film is used, it is possible to suppress the occurrence of optical defect points where "in-plane retardation differs from the surroundings". Therefore, in the reflection suppression film manufactured using this optical film, it is possible to suppress the occurrence of a place where reflection cannot be suppressed as intended.

The composite liquid crystal layer included in an optical film generally has a good surface state. According to this, the unevenness of the thickness of the composite liquid crystal layer is small, so the optical film can reduce the unevenness of the in-plane retardation.

The optical film is preferably excellent in transparency. Specifically, the total light transmittance of the optical film is preferably 75% or more, more preferably 80% or more, and particularly preferably 84% or more. The haze of the optical film is preferably 5% or less, more preferably 3% or less, and even more preferably 1% or less. The total light transmittance can be measured with a UV-visible spectrometer in the wavelength range of 400 nm to 700 nm. In addition, the haze can be measured using a haze meter.

The thickness of the optical film is preferably 0.5 μm or more, more preferably 1.0 μm or more, and more preferably 300 μm or less, and more preferably 200 μm or less.

(2.6. Manufacturing method of optical film)

The manufacturing method of an optical film is arbitrary as long as the desired optical film can be obtained. In one embodiment, the optical film can be manufactured by a manufacturing method including the following steps:
(Iv) a step of directly forming a layer body of the inclined layer composition on a specific surface of the liquid crystal alignment layer;
(V) a step of orienting the reverse dispersion liquid crystalline compound contained in the layer body of the inclined layer composition; and (vi) a step of curing the layer body of the inclined layer composition to obtain a liquid crystal inclined layer.

In step (iv), a layered body of the inclined layer composition is directly formed on a specific surface of the liquid crystal alignment layer. Here, the state that the other layer is formed on the surface of a layer is "direct", which means that there is no other layer between these two layers.

Before the layered body of the inclined layer composition is formed on a specific surface of the liquid crystal alignment layer, a treatment such as rubbing treatment may be applied to the specific surface to impart an orientation restricting force. However, even if a specific surface of the liquid crystal alignment layer is not subjected to a special treatment, the liquid crystal alignment layer has an alignment restricting force that appropriately orients the reverse dispersion liquid crystal compound contained in the layer body of the inclined layer composition formed on the specific surface. Therefore, from the viewpoint of reducing the number of processes to efficiently manufacture the optical film, the process (iv) includes not including a rubbing treatment on a specific surface of the liquid crystal alignment layer, that is, forming an inclined layer composition directly on the specific surface of the liquid crystal alignment layer. The matter of layers is better.

In the step (iv) of forming a layered body of the inclined layer composition, the inclined layer composition is usually prepared in a fluid state. Therefore, the inclined layer composition is usually coated on a specific surface of the liquid crystal alignment layer to form a layered body of the inclined layer composition. Examples of the method for applying the inclined layer composition include the same examples as those described above as the method for applying the alignment layer composition. Since the liquid crystal alignment layer is formed of a cured product containing a reverse dispersion liquid crystalline compound, the liquid crystal alignment layer generally has a high affinity for a tilted layer composition containing a reverse dispersion liquid crystalline compound. According to this, the specific surface of the liquid crystal alignment layer generally has a good affinity for the inclined layer composition, and the coating property of the inclined layer composition to the specific surface is good. Therefore, the occurrence of repulsion and unevenness can be suppressed, and a layered body of the inclined layer composition having a good surface state can be formed. Moreover, since the surface state of the layer body of the inclined layer composition can be optimized in this way, the surface state of the liquid crystal inclined layer obtained by curing the layer body of the inclined layer composition can be optimized, and even the surface state of the composite liquid crystal layer can be optimized.

After the step (iv) of forming a layered body of the inclined layer composition, a step (v) of orienting the reverse dispersion liquid crystalline compound contained in the layered body of the inclined layer composition is performed. Thereby, in the layered body of the inclined layer composition, liquid crystal compounds such as a reverse dispersion liquid crystal compound are aligned.

Generally, in the in-plane direction, the reverse dispersion liquid crystal compound contained in the layer body of the inclined layer composition is aligned with the reverse dispersion liquid crystal compound contained in the liquid crystal alignment layer by the orientation restricting force of the specific surface of the liquid crystal alignment layer. Orientation is oriented in the same direction. On the other hand, in the thickness direction, the reverse dispersion liquid crystalline compound contained in the layer body of the inclined layer composition is oriented such that at least a portion thereof is inclined with respect to the plane of the layer body (that is, with respect to the in-plane direction). At this time, the molecules of the reverse dispersion liquid crystalline compound contained in the layer body of the inclined layer composition are largely inclined with respect to the plane of the layer body (that is, with respect to the in-plane direction) through the action of the liquid crystal alignment layer. Therefore, the substantial maximum inclination angle of the molecules of the reverse dispersion liquid crystalline compound contained in the layer body of the inclined layer composition can be increased.

As described above, the liquid crystal alignment layer has a high affinity for the composition of the inclined layer. Therefore, the composition of the inclined layer is compatible with the liquid crystal alignment layer, and the orientation of the molecules is not easily confused. In addition, in the liquid crystal alignment layer, the occurrence of alignment defects is suppressed, so the occurrence of alignment defects in the inclined layer composition, which are caused by the alignment defects of the liquid crystal alignment layer, is also suppressed. Accordingly, the orientation state can be made uniform in the in-plane direction in the inclined layer composition. Therefore, in the step (v), the occurrence of orientation defects is generally suppressed.

The specific operation in the step (v) of orienting the reverse dispersion liquid crystalline compound included in the layer body of the inclined layer composition may be the same as the step of orienting the reverse dispersion liquid crystalline compound included in the layer body of the alignment layer composition. (Ii) Same. Thereby, the same advantages as those obtainable in the alignment layer composition and the liquid crystal alignment layer can also be obtained in the tilted layer composition and the liquid crystal tilted layer. In particular, in step (v), as in step (ii), the temperature conditions of the layered body of the inclined layer composition in step (v) are the same as those of the test composition corresponding to the inclined layer composition. It is preferable that the viscosity of the components is generally performed in the same manner as the temperature conditions of 800 cP or less.

After the step (v) of orienting the reverse dispersion liquid crystalline compound, a step (vi) of curing the layer body of the inclined layer composition to obtain a liquid crystal inclined layer is performed. Thereby, an optical film including a composite liquid crystal layer including a liquid crystal alignment layer and a liquid crystal inclined layer can be obtained. The specific operation in the step (vi) of curing the layer body of the inclined layer composition may be the same as the step (iii) of curing the layer body of the alignment layer composition. Thereby, the same advantages as those obtainable in the alignment layer composition and the liquid crystal alignment layer can also be obtained in the tilted layer composition and the liquid crystal tilted layer.

The method for producing an optical film may further include any step combined with the above steps.

The method for manufacturing an optical film may include, for example, a step of further forming another liquid crystal inclined layer on the liquid crystal inclined layer.

The method for producing an optical film may include, for example, a step of forming an arbitrary layer on the liquid crystal inclined layer.

Furthermore, the method may further include a step of forming an arbitrary layer body on the opposite side of the liquid crystal alignment layer from the liquid crystal inclined layer.

When a layered body formed on the support surface of the substrate is used as the liquid crystal alignment layer, a composite liquid crystal layer is formed on the substrate according to the aforementioned manufacturing method. A film including this substrate and a composite liquid crystal layer can also be used as an optical film. Moreover, the manufacturing method of an optical film may include the process of peeling a base material. In this case, the composite liquid crystal layer itself can be used as an optical film.

The method for producing an optical film may include, for example, a step of transferring a composite liquid crystal layer formed on a substrate to an arbitrary film layer. According to this, the method for manufacturing an optical film may also include, for example, after laminating a composite liquid crystal layer formed on a substrate with an arbitrary thin film layer, peeling off the substrate as required to obtain an optical film including the composite liquid crystal layer and an arbitrary thin film layer. Thin film process. In this case, an appropriate adhesive or bonding agent may be used for bonding.

According to the aforementioned general manufacturing method, a long liquid crystal alignment layer can be used to obtain a long optical film. Such a long optical film can be continuously manufactured and has excellent productivity. In addition, since it can be bonded to another film by a roller, it is excellent in productivity at this point. Usually long optical films are rolled up, stored and transported in a roll state.

[3. 1/4 wave plate]

A quarter wave plate according to an embodiment of the present invention includes the liquid crystal alignment layer or the optical film. In addition, the 1/4 wavelength plate may further include any layer combination in a liquid crystal alignment layer or an optical film.

This 1/4 wave plate has the in-plane retardation in the above-mentioned range as an in-plane delay that can function as a 1/4 wave plate. By combining a 1/4 wavelength plate with a linear polarizer, a circular polarizer that can be used as a reflection suppression film can be obtained. The circularly polarizing plate thus obtained can be used as a reflection suppressing film which can suppress the occurrence of optical defects, has in-plane retardation with reverse wavelength dispersion, and has excellent viewing angle characteristics.

[4. Polarizer]

A polarizing plate according to an embodiment of the present invention includes the liquid crystal alignment layer or the optical film. Generally, a polarizing plate includes a linear polarizer in combination with a liquid crystal alignment layer or an optical film. The polarizing plate is preferably capable of functioning as a circular polarizing plate or an elliptical polarizing plate. Such a polarizing plate, by being provided on an organic EL display panel, can suppress reflection of external light in the front direction of the display surface of the organic EL display panel. At this time, since the liquid crystal alignment layer and the optical film have in-plane retardation with reverse wavelength dispersion, it is possible to suppress reflection of external light in a wide wavelength range. In addition, the liquid crystal alignment layer and the optical film can be seen from the fact that the maximum inclination angle of the molecules of the reverse-dispersion liquid crystalline compound is large. Since the inclination angle of the molecules of the overall reverse-dispersion liquid crystalline compound is large, it is not only in the in-plane direction, but also The birefringence can be adjusted moderately in the thickness direction. Therefore, the polarizing plate can suppress the reflection of external light not only in the front direction of the display surface of the organic EL display panel but also in the oblique direction. Therefore, by using this polarizing plate, an organic EL display panel with a wide viewing angle can be realized. Furthermore, since the occurrence of alignment defects is suppressed in the liquid crystal alignment layer and the optical film, it is possible to suppress the occurrence of a place where the reflection cannot be suppressed as intended.

Examples of the linear polarizer include a film obtained by uniaxially stretching in a boric acid bath after adsorbing iodine or a dichroic dye on a polyvinyl alcohol film; and by adsorbing iodine or a dichroic dye on A film obtained by extending a polyvinyl alcohol film and further modifying a part of the polyvinyl alcohol unit in the molecular chain to a polyvinylidene unit. In addition, as another example of the linear polarizer, a polarizer having a function of separating polarized light into reflected light and transmitted light, such as a grid polarizer and a multilayer polarizer, may be mentioned. Among these, as the linear polarizer, a polarizer containing polyvinyl alcohol is preferred.

If natural light is made incident on the linear polarizer, only a single direction of polarized light will pass through. The degree of polarization of the linear polarizer is not particularly limited, but it is preferably 98% or more, and more preferably 99% or more.

The thickness of the linear polarizer is preferably 5 μm to 80 μm.

In the case where the polarizing plate is to function as a circular polarizing plate, the angle between the slow axis of the liquid crystal alignment layer or the optical film is preferably 45 ° or closer to the polarizing light absorption axis of the linear polarizer. The foregoing angle is specifically, preferably 45 ° ± 5 °, more preferably 45 ° ± 4 °, and even more preferably 45 ° ± 3 °.

The polarizing plate may include an arbitrary layer body in addition to the linear polarizer, the liquid crystal alignment layer, and the optical film. Examples of the arbitrary layer body include a bonding layer for bonding a linear polarizer to a liquid crystal alignment layer or an optical film; a polarizer protective film layer for protecting the linear polarizer; and the like.

[5. Organic EL display panel]

An organic EL display panel according to an embodiment of the present invention includes the liquid crystal alignment layer or the optical film. Generally, an organic EL display panel includes the aforementioned polarizing plate including a liquid crystal alignment layer or an optical film. Such an organic EL display panel generally includes an organic EL element as a display element, and a polarizing plate is provided on the viewing side of the organic EL element. The polarizing plate is disposed so that a liquid crystal alignment layer or an optical film is provided between the organic EL element and the linear polarizer. In this configuration, the polarizing plate can function as a reflection suppressing film.

In the following, a case where a polarizing plate functions as a circular polarizing plate is taken as an example to explain the mechanism of suppressing reflection. Only a part of the linearly polarized light entering from the outside of the device passes through the linear polarizer, and then passes through the liquid crystal alignment layer or the optical film, thereby becoming circularly polarized light. The circularly polarized light is reflected by constituent elements (reflective electrodes of the organic EL element, etc.) that reflect light in the organic EL display panel, and again passes through the liquid crystal alignment layer or the optical film, thereby becoming positively polarized with the incident linearly polarized light. The linearly polarized light intersects the vibration direction and does not pass through the linear polarizer. Here, the vibration direction of the linearly polarized light means the vibration direction of the electric field of the linearly polarized light. Thereby, the function of suppressing reflection is achieved. The principle of such reflection suppression can be referred to Japanese Patent Laid-Open No. H9-127885.

An organic EL element generally includes a transparent electrode layer, a light emitting layer, and an electrode layer in order, and light must be generated from the light emitting layer by applying a voltage from the transparent electrode layer and the electrode layer. Examples of the material constituting the organic light-emitting layer include materials of a polyparastyrene type, a polyfluorene type, and a polyvinyl carbazole type. In addition, the light emitting layer may include a stack of a plurality of layers having different emission colors, or a mixed layer in which a layer of a certain pigment is doped with a different pigment. Furthermore, the organic EL element may be provided with functional layers such as a hole injection layer, a hole transport layer, an electron injection layer, an electron transport layer, an equipotential surface forming layer, and a charge generating layer.

In addition, in the organic EL display panel, a liquid crystal alignment layer or an optical film may be provided for applications other than the reflection suppression film.

『Examples』

The following examples are disclosed to illustrate the present invention in detail. However, the present invention is not limited to the embodiments disclosed below, and can be arbitrarily changed and implemented without departing from the scope of the patent application of the present invention and its equivalent scope.

In the following description, the "%" and "part" of the amount are based on weight unless otherwise noted. In addition, the operations described below are performed in normal temperature and pressure atmosphere unless otherwise noted.

In addition, the supporting substrate included in the intermediate film and the optical film manufactured in the examples and comparative examples described below has optical isotropy, and therefore does not affect the measurement result of the delay. Therefore, the measurement of retardation in the examples and comparative examples described below was performed using an intermediate film or an optical film including a supporting substrate as a sample.

[Evaluation method]

(1. Method for measuring log P of fluorine-based surfactants)

(1-1. Preparation method of sample solution containing fluorine-based surfactant)

A sample solution containing 1% by weight of a fluorine-based surfactant was prepared. As a solvent of this sample solution, tetrahydrofuran or acetonitrile was used. When the fluorine-based surfactant before being mixed with tetrahydrofuran or acetonitrile is a solution containing the fluorine-based surfactant and a diluent solvent, the content of the fluorine-based surfactant in the obtained sample solution becomes 1% by weight In this way, the amount of tetrahydrofuran or acetonitrile is adjusted.

(1-2. HPLC / ELSD analysis)

Fluorine-based interfacial activity was performed under the following HPLC / ELSD analysis conditions by a method based on JIS 7260-117: 2006 "Measurement of Partition Coefficient (1-octanol / water)-High Performance Liquid Chromatography". HPLC / ELSD analysis of the aforementioned sample solution of the agent, and measuring the residence time (rt).

・ HPLC / ELSD analysis conditions
LC system: LC-20A (manufactured by Shimadzu Corporation)
Column: Inertsil ODS-3 3.0 × 150 mm, 5 μm (manufactured by GL Sciences)
Mobile phase: A water
B acetonitrile / tetrahydrofuran = 8/2 (vol / vol)
Acetonitrile: for high performance liquid chromatography (made in Japan)
Tetrahydrofuran: inhibitor-free, for HPLC (manufactured by SIGMA-ALDRICH)
Time schedule: 0 min to 15 min B is 30% to 100%
15 min to 25 min B is 100%
Column temperature: 45 ℃
Flow: 0.8 mL / min
Injection volume: 10 μL (in the case of low detection sensitivity of the sample, adjust to 50 μL or 100 μL)
Detection: ELSD-LTII (Shimadzu Corporation) Gain6, 350 kPa, 65 ° C

(1-3. Derivation of standard curve)

Prepare marked compounds as shown in Table 1 below. The marked compounds disclosed in Table 1 are compounds whose log P values described in JIS 7260-117: 2006 are known. Aside from using this mark compound instead of the fluorine-based surfactant, a sample solution containing each mark compound was prepared by following the method described in (1-1. Method for preparing a sample solution containing a fluorine-based surfactant). After that, the obtained sample solution was subjected to HPLC / ELSD analysis under the analysis conditions described above (1-2. HPLC / ELSD analysis), and the retention time was measured. However, the temperature of the ELSD detector is set to 25 ° C.

"Table 1"
[Table 1. Marked compounds and their analysis results]

In a coordinate system with the residence time as the horizontal axis and log P as the vertical axis, the analysis results of the aforementioned marker compounds were plotted, and an approximate straight line was prepared by the least square method. Use this approximate straight line as the standard curve.

(1-4. Calculation of log P of fluorine-based surfactants)

By substituting the residence time measured for each fluorine-based surfactant into the aforementioned standard curve, the log P of this fluorine-based surfactant was obtained. When one fluorine-based surfactant detects multiple peaks indicating retention time in HPLC / ELSD analysis, the peak-top value of the peak with the largest area is used as the retention time of the fluorine-based surfactant, and the log is obtained. P.

(2. Measuring method of thickness)

The thickness of the layer was measured using a film thickness meter ("F20-EXR" manufactured by FILMETRICS).

(3. Measurement method of the amount of fluorine atoms on the surface of the liquid crystal alignment layer)

A sample film of 1 cm square was cut from an intermediate film having a supporting substrate and a liquid crystal alignment layer. The surface on the liquid crystal alignment layer side was set as the front surface, and the sample film was fixed to a sample stage. At this time, a conductive tape was used for fixing the sample film. The aforementioned sample stage was mounted on the following X-ray photoelectron spectroscopy system, and the amount of fluorine atoms on the surface of the liquid crystal alignment layer (the surface opposite to the supporting substrate) was measured under the following conditions. According to this method, the molar content of fluorine (F) atoms contained in all atoms excluding hydrogen (H) existing on the surface of the liquid crystal alignment layer can be measured.
System: "AXIS ULTRA" by Kratos Analytical
X-ray excitation: Al Kα line
Filament Emission: 10 mA
AnodeHT: 15 kV
Neutralizer: Electron Neutralizer
Neutralization conditions Filament Current (filament current): 1.55 A
Charge Balance: 3.3 V
Filament Bias (filament bias): 1.5 V
Analysis area: about 700 μm × 300 μm
Photoelectron detection angle: 0 ° (angle between sample surface and detector: 90 °)

(4. Measuring method of substantial maximum tilt angle)

FIG. 5 is a perspective view illustrating the measurement direction when the retardation of the liquid crystal alignment layer 400 is measured from the oblique direction. In FIG. 5, the arrow A1 indicates the slow axis direction in the plane of the liquid crystal alignment layer 400, the arrow A2 indicates the fast axis direction in the plane of the liquid crystal alignment layer 400, and the arrow A3 indicates the thickness direction of the liquid crystal alignment layer 400.

Using a phase difference meter ("AxoScan" manufactured by Axometrics), as shown in FIG. 5, the retardation of the liquid crystal alignment layer 400 was measured in a range of an incident angle θ of -50 ° to 50 °. At this time, the measurement direction A4 is set to be perpendicular to the fast axis direction A2 in the plane of the liquid crystal alignment layer 400. The measurement wavelength was 590 nm.

The measured delay is analyzed by the analysis software (Axometrics' analysis software "Multi-Layer Analysis"); the analysis conditions are an analysis wavelength of 590 nm and a number of layer divisions of 20 layers. The substantial maximum tilt angle of the molecules of the liquid crystal compound included in the liquid crystal alignment layer 400.

In addition, the substantial maximum tilt angle of the molecules of the liquid crystal compound contained in the composite liquid crystal layer of the optical film is measured by the retardation of the composite liquid crystal layer instead of the delay of the liquid crystal alignment layer. The measurement method of the substantially maximum tilt angle of the molecules of the liquid crystal compound is the same method.

For the composite liquid crystal layer, the obtained substantially maximum tilt angle was evaluated on the basis of the following criteria.
"A": The substantial maximum tilt angle in the composite liquid crystal layer is 40 ° or more and 85 ° or less.
"B": The substantial maximum tilt angle in the composite liquid crystal layer is 30 ° or more and less than 40 °.
"C": The substantial maximum tilt angle in the composite liquid crystal layer is less than 30 °.

(5. Evaluation method of the surface state of the composite liquid crystal layer)

A pair of linear polarizers (polarizer and analyzer) are superimposed on a light-transmitting table so as to be parallel Nicollium. The term “parallel nicols” used herein means that the polarization transmission axes of the linear polarizers are parallel.

The optical films produced in the examples or comparative examples were cut into a 16 cm square size to obtain a film sheet for measurement. This film sheet is placed between the linear polarizers placed on a light-transmitting table as described above. At this time, the slow axis of the film sheet is set at an angle of approximately 45 ° with respect to the absorption axis of the linear polarizer when viewed from the thickness direction. After that, it was observed visually. Corresponding to the uniformity of the observed image (uniformity of retardation), the surface state of the composite liquid crystal layer was evaluated by the following criteria.
A: There is no unevenness in the observed image.
C: Unevenness was observed in the observed image.

Incidentally, in addition, a pair of linear polarizers provided on the aforementioned light-transmitting table is provided with a supporting substrate used for manufacturing an optical film for visual observation. As a result, when only a support substrate without a composite liquid crystal layer was used and observed instead of the thin film sheet, the entire surface was almost uniform and no unevenness was observed. From this result, it was confirmed that the unevenness observed in the foregoing evaluation was caused by the surface state of the composite liquid crystal layer.

(6. Evaluation method of directional defects)

Prepare a sample film (intermediate film or optical film) containing a liquid crystal cured layer (liquid crystal alignment layer; or a composite liquid crystal layer composed of a liquid crystal alignment layer and a liquid crystal inclined layer) formed from a cured product of a liquid crystal composition as a sample . The polarized light microscope was used to penetrate through the aforementioned liquid crystal cured layer under crossed Nicols. During this observation, the objective lens was set to 20 times. As a result of self-observation, orientation defects were evaluated by the following criteria.
"A": The entire surface is almost uniform, and no orientation defect is seen.
"C": Seeing orientation defects.

(7. Evaluation method of inverse wavelength dispersion)

A phase difference meter ("AxoScan" manufactured by Axometrics) was used to measure the in-plane retardation of the optical film (that is, the retardation of the composite liquid crystal layer at an incident angle of 0 °) at the measurement wavelengths of 450 nm and 550 nm. From the measured values of in-plane retardation Re (450) and Re (550) at the measurement wavelengths of 450 nm and 550 nm, the inverse wavelength dispersion of the optical film was evaluated by the following criteria.
"A": Re (450) / Re (550) <0.9
"B": 0.9 ≦ Re (450) / Re (550) ≦ 1.0
"C": Re (450) / Re (550)> 1.0

(8. Evaluation method of viewing angle characteristics)

A retardation meter ("AxoScan" manufactured by Axometrics) was used to measure the retardation of the optical film in the range of the incident angle θ of -50 ° to 50 °. At this time, the measurement direction is set to be perpendicular to the fast axis direction in the plane of the optical film. The measurement wavelength was 590 nm.

Calculate the average R (± 50 °) of the retardation R (-50 °) at the angle of incidence θ of −50 ° and the retardation R (+ 50 °) at the angle of incidence θ of + 50 °. Then, this average value R (± 50 °) is divided by the in-plane retardation R (0 °) with an incident angle θ of 0 °, and the average retardation ratio R (± 50 °) / R (0 °) is obtained. The closer the average retardation ratio R (± 50 °) / R (0 °) is to 1.00, the more excellent viewing angle characteristics can be achieved in the organic EL display panel. Then, based on the value of the aforementioned average retardation ratio R (± 50 °) / R (0 °), the viewing angle characteristics were evaluated on the following basis.
"A": 0.93 ≦ R (± 50 °) / R (0 °) ≦ 1.10
"B": 0.90 ≦ R (± 50 °) / R (0 °) <0.93
"C": R (± 50 °) / R (0 °) <0.90

(9. How to check the molecular tilt of at least a part of the liquid crystal compound)

Prepare a sample film (intermediate film or optical film) containing a liquid crystal cured layer (liquid crystal alignment layer; or a composite liquid crystal layer composed of a liquid crystal alignment layer and a liquid crystal inclined layer) formed of a cured product of a liquid crystal composition as a sample . A retardation meter ("AxoScan" manufactured by Axometrics) was used to measure the retardation of the liquid crystal cured layer in the range of the incident angle θ of -50 ° to 50 °. At this time, the measurement direction is set to be perpendicular to the fast axis direction in the plane of the liquid crystal cured layer. The measurement wavelength was 590 nm.

Divide the measured retardation R (θ) of the liquid crystal cured layer at the incident angle θ by the retardation R (0 °) of the liquid crystal cured layer at the incident angle 0 °, and find the retardation ratio R (θ) / R (0 °). A graph in which the obtained retardation ratio R (θ) / R (0 °) is set on the vertical axis and the incident angle θ is set on the horizontal axis is plotted. Then, based on whether the obtained graph is asymmetric with respect to θ = 0 °, the oblique orientation of the molecules was confirmed on the following basis.
"A": The retardation ratio R (θ) / R (0 °) is asymmetric with θ = 0 °, so at least a part of the molecules of the liquid crystal compound contained in the liquid crystal cured layer is relative to the layer plane of the liquid crystal cured layer ( That is, it is oriented obliquely with respect to the in-plane direction.
"C": The retardation ratio R (θ) / R (0 °) is symmetrical to θ = 0 °. Therefore, all molecules of the liquid crystal compound contained in the liquid crystal cured layer are relative to the layer plane of the liquid crystal cured layer (that is, relative to In-plane) parallel or perpendicular.

『Example 1』

(Preparation of liquid crystal composition)

100 parts by weight of a polymerizable "reverse dispersion liquid crystalline compound 1" represented by the following formula, and a fluorine-based surfactant ("S420" manufactured by AGC Seimi Chemical Co., Ltd .; log P = 5.3) 0.075 weight were mixed Parts, 4.3 parts by weight of a photopolymerization initiator ("IrgacureOXE04" manufactured by BASF Corporation), and 148.5 parts by weight of cyclopentanone as a solvent and 222.8 parts by weight of 1,3-dioxy, to produce a liquid crystal composition.

『Hua27』

Inverse dispersion liquid crystalline compound 1

(Preparation of supporting substrate)

A resin film ("ZeonorFilm ZF16" manufactured by Japan's Rui On Co., Ltd .; thickness: 100 μm) made of a thermoplastic norylene resin with a protective film laminated on one side was prepared as a supporting substrate. This supporting substrate is an optically isotropic film without retardation. From this support substrate, the protective film is peeled off, and the protective peeled surface is subjected to corona treatment. Subsequently, the corona-treated surface of the supporting substrate is subjected to a rubbing treatment.

(Formation of liquid crystal alignment layer)

On the friction-treated surface of the supporting substrate, a wire rod was used to coat the liquid crystal composition as the alignment layer composition to form a layered body of the liquid crystal composition.

Subsequently, the layer of the liquid crystal composition was heated in an oven set at 145 ° C. for 4 minutes to orient the liquid crystal compound in the layer. The aforementioned heating conditions are temperature conditions in which the viscosity of the remaining components of the test composition corresponding to the liquid crystal composition used is 170 cP.

After that, the layered body of the liquid crystal composition was irradiated with 500 mJ / cm ² of ultraviolet rays in a nitrogen environment, and the layered body of the liquid crystal composition was cured to obtain a liquid crystal alignment layer having a thickness of 0.3 μm. Thereby, an intermediate film including a supporting substrate and a liquid crystal alignment layer was obtained.

Using this intermediate film, the surface fluorine atom amount M _F [mole%] on the surface of the liquid crystal alignment layer on the side opposite to the supporting substrate, the substantial maximum tilt angle in the liquid crystal alignment layer, and the liquid crystal alignment were evaluated by the aforementioned methods. The alignment defect of the layer and the oblique directivity of the liquid crystal alignment layer.

(Formation of liquid crystal inclined layer)

On the surface of the liquid crystal alignment layer, a rubbing treatment is not applied, and the "residual liquid crystal composition used to form the liquid crystal alignment layer" is coated with a wire rod as an inclined layer composition to form a layer body of the liquid crystal composition.

Subsequently, the layered body of this liquid crystal composition is heated in an oven set at 145 ° C. for 4 minutes in the same manner as the above-mentioned step of forming the liquid crystal alignment layer, so as to orient the liquid crystal compound in the layered body.

Thereafter, the layered body of the liquid crystal composition was irradiated with 500 mJ / cm ² of ultraviolet rays in a nitrogen environment, and the layered body of the liquid crystal composition was cured to obtain a liquid crystal inclined layer.

Thus, an optical film having a "support substrate" and "a composite liquid crystal layer including a liquid crystal alignment layer and a liquid crystal inclined layer formed on this support substrate" was obtained. The thickness of the composite liquid crystal layer was 3.2 μm.

Using the obtained optical film, the surface state, alignment defects, reverse wavelength dispersion, substantial maximum tilt angle, tilt orientation, and viewing angle characteristics of the composite liquid crystal layer were evaluated by the methods described above. The in-plane retardation of the optical film at a wavelength of 590 nm is 145 nm.

『Example 2』

The amount of the fluorine-based surfactant ("S420" manufactured by AGC Seimi Chemical Co., Ltd.) was changed from 0.075 parts by weight to 0.150 parts by weight.

Except for the above matters, the same operation as in Example 1 was performed to manufacture and evaluate an intermediate film including a liquid crystal alignment layer and an optical film including a composite liquid crystal layer. The in-plane retardation of the optical film at a wavelength of 590 nm is 145 nm.

[Example 3]

The amount of the fluorine-based surfactant ("S420" manufactured by AGC Seimi Chemical Co., Ltd.) was changed from 0.075 parts by weight to 0.150 parts by weight.

The thickness of the liquid crystal alignment layer was changed from 0.3 μm to 1.4 μm.

Except for the above matters, the same operation as in Example 1 was performed to manufacture and evaluate an intermediate film including a liquid crystal alignment layer and an optical film including a composite liquid crystal layer. The in-plane retardation of the optical film at a wavelength of 590 nm was 139 nm.

[Example 4]

The amount of the fluorine-based surfactant ("S420" manufactured by AGC Seimi Chemical Co., Ltd.) was changed from 0.075 parts by weight to 0.150 parts by weight.

The thickness of the liquid crystal alignment layer was changed from 0.3 μm to 2.5 μm.

Except for the above matters, the same operation as in Example 1 was performed to manufacture and evaluate an intermediate film including a liquid crystal alignment layer and an optical film including a composite liquid crystal layer. The in-plane retardation of the optical film at a wavelength of 590 nm is 158 nm.

[Example 5]

The amount of the fluorine-based surfactant ("S420" manufactured by AGC Seimi Chemical Co., Ltd.) was changed from 0.075 parts by weight to 0.400 parts by weight.

The thickness of the liquid crystal alignment layer was changed from 0.3 μm to 1.0 μm.

Except for the above matters, the same operation as in Example 1 was performed to manufacture and evaluate an intermediate film including a liquid crystal alignment layer and an optical film including a composite liquid crystal layer. The in-plane retardation of the optical film at a wavelength of 590 nm is 157 nm.

[Example 6]

A fluorine-based surfactant (“FTERGENT FTX-209” manufactured by NEOS Corporation; log P = 6.3) was used in an amount of 0.150 parts by weight instead of 0.075 parts by weight of a fluorine-based surfactant (“S420” manufactured by AGC Seimi Chemical Co., Ltd.).

Except for the above matters, the same operation as in Example 1 was performed to manufacture and evaluate an intermediate film including a liquid crystal alignment layer and an optical film including a composite liquid crystal layer. The in-plane retardation of the optical film at a wavelength of 590 nm is 147 nm.

[Example 7]

Instead of 100 parts by weight of "reverse dispersion liquid crystalline compound 1", 100 parts by weight of "reverse dispersion liquid crystalline compound 2" shown in the following formula was used.

In addition, the amount of the fluorine-based surfactant ("S420" manufactured by AGC Seimi Chemical Co., Ltd.) was changed from 0.075 parts by weight to 0.150 parts by weight.

Then, the thickness of the liquid crystal alignment layer was changed from 0.3 μm to 1.4 μm.

Except for the above matters, the same operation as in Example 1 was performed to manufacture and evaluate an intermediate film including a liquid crystal alignment layer and an optical film including a composite liquid crystal layer.

In addition, in this Example 7, the heating conditions when the layered body of the liquid crystal composition is heated in an oven are temperature conditions corresponding to the residual component viscosity of the test composition of the liquid crystal composition used being 255 cP.

The in-plane retardation of the optical film at a wavelength of 590 nm was 149 nm.

『Chem 28』

Inverse dispersion liquid crystalline compound 2

[Comparative Example 1]

The thickness of the liquid crystal alignment layer was changed from 0.3 μm to 2.0 μm.

Except for the above matters, the same operation as in Example 1 was performed to manufacture and evaluate an intermediate film including a liquid crystal alignment layer and an optical film including a composite liquid crystal layer.

[Comparative Example 2]

The amount of the fluorine-based surfactant ("S420" manufactured by AGC Seimi Chemical Co., Ltd.) was changed from 0.075 parts by weight to 0.500 parts by weight.

The thickness of the liquid crystal alignment layer was changed from 0.3 μm to 2.0 μm.

Except for the above matters, the same operation as in Example 1 was performed to manufacture and evaluate an intermediate film including a liquid crystal alignment layer and an optical film including a composite liquid crystal layer.

[Comparative Example 3]

The amount of the fluorine-based surfactant ("S420" manufactured by AGC Seimi Chemical Co., Ltd.) was changed from 0.075 parts by weight to 0.150 parts by weight.

The thickness of the liquid crystal alignment layer was changed from 0.3 μm to 3.4 μm.

Then, the thickness of the composite liquid crystal layer was changed from 3.2 μm to 3.7 μm.

Except for the above matters, the same operation as in Example 1 was performed to manufacture and evaluate an intermediate film including a liquid crystal alignment layer and an optical film including a composite liquid crystal layer.

[Comparative Example 4]

The amount of the fluorine-based surfactant ("S420" manufactured by AGC Seimi Chemical Co., Ltd.) was changed from 0.075 parts by weight to 0.400 parts by weight.

The thickness of the liquid crystal alignment layer was changed from 0.3 μm to 3.3 μm.

Then, the thickness of the composite liquid crystal layer was changed from 3.2 μm to 3.6 μm.

Furthermore, the oven setting temperature is lowered in the process of orienting the liquid crystal compound contained in the layered body of the liquid crystal composition. This set temperature is a temperature at which the viscosity of the residual component of the test composition of the liquid crystal composition becomes greater than 800 cP. Thereby, the orientation direction of the molecules of the reverse dispersion liquid crystalline compound contained in the liquid crystal alignment layer becomes parallel to the plane of the layer body (that is, parallel to the in-plane direction).

Except for the above matters, the same operation as in Example 1 was performed to manufacture and evaluate an intermediate film including a liquid crystal alignment layer and an optical film including a composite liquid crystal layer.

In this Comparative Example 4, in the liquid crystal alignment layer included in the intermediate film and the composite liquid crystal layer included in the optical film, it was not confirmed that the molecules of the reverse-dispersing liquid crystal compound are relative to the plane of the layer body (that is, relative to the plane of the layer body). In-plane direction) tilt.

[Comparative Example 5]

100 parts by weight of a polymerizable "cis-dispersing liquid crystalline compound 3" represented by the following formula, 0.150 parts by weight of a fluorine-based surfactant ("S420" manufactured by AGC Seimi Chemical Co., Ltd.) are mixed, and photopolymerization is started. 4.3 parts by weight of an initiator ("IrgacureOXE04" manufactured by BASF) and "148.5 parts by weight of cyclopentanone and 222.8 parts by weight of 1,3-dioxy" as a solvent were used to produce a liquid crystal composition.

『Hua 29』

Cis-dispersing liquid crystalline compound 3

A liquid crystal composition containing the aforementioned para-dispersive liquid crystal compound 3 was used as the alignment layer composition. The thickness of the liquid crystal alignment layer was changed from 0.3 μm to 0.5 μm. Except for the above matters, the production and evaluation of the intermediate film including the liquid crystal alignment layer were performed by the same operation as in the step of forming the liquid crystal alignment layer in Example 1.

Except that the thickness of the composite liquid crystal layer was changed from 3.2 μm to 2.8 μm, the same operation as in the formation step of the liquid crystal inclined layer of Example 1 was performed. On the surface of the intermediate film alignment layer obtained in this manner, liquid crystal properties including reverse dispersion The liquid crystal composition of Compound 1 was used to form a liquid crystal tilted layer to obtain an optical film. Using the obtained optical film, the surface state, alignment defects, reverse wavelength dispersion, substantial maximum tilt angle, tilt orientation, and viewing angle characteristics of the composite liquid crystal layer were evaluated by the methods described above.

[result]

The results of the above examples and comparative examples are shown in Tables 2 to 3 below. In the following tables, the meaning of the abbreviations is as follows.
Inverse dispersion 1: Inverse dispersion liquid crystalline compound 1.
Inverse dispersion 2: Inverse dispersion liquid crystalline compound 2.
Cis dispersion 3: Cis dispersion liquid crystal compound 3.
S420: A fluorine-based surfactant "S420" manufactured by AGC Seimi Chemical Co., Ltd.
FTX209: A fluorine-based surfactant "FTERGENT FTX-209" manufactured by NEOS Corporation.
M _F : the surface fluorine atom amount of the liquid crystal alignment layer on the side opposite to the supporting substrate.

"Table 2"
[Table 2. Results of Examples]

"table 3"
[Table 3. Results of Comparative Example]

[discuss]

As can be seen from Table 3, in Comparative Example 1 in which the M _F / T of the liquid crystal alignment layer is too small, the occurrence of alignment defects in the liquid crystal alignment layer cannot be suppressed. Therefore, alignment defects occur in the composite liquid crystal layer included in the optical film. Furthermore, in Comparative Example 1, the substantial maximum tilt angle of the molecules of the reverse-dispersion liquid crystalline compound contained in the liquid crystal alignment layer is small, and the composite liquid crystal layer included in the optical film also has a small maximum tilt angle, so the viewing angle characteristics are small. inferior.

Moreover, in Comparative Example 2 where the M _F / T of the liquid crystal alignment layer is too large, since the substantial maximum tilt angle of the molecules of the reverse-dispersing liquid crystal compound contained in the liquid crystal alignment layer is small, the composite liquid crystal layer included in the optical film is also The actual maximum tilt angle is small, so viewing angle characteristics are poor.

Furthermore, in Comparative Example 3, where the thickness T of the liquid crystal alignment layer is too thick, the substantial maximum tilt angle of the molecules of the reverse dispersion liquid crystalline compound contained in the liquid crystal alignment layer is small, and the composite liquid crystal layer included in the optical film is also substantially the largest. The tilt angle is small, so viewing angle characteristics are poor.

In addition, in Comparative Example 4 in which the molecules of the reverse dispersion liquid crystalline compound contained in the liquid crystal alignment layer are not inclined with respect to the plane of the layer body (that is, with respect to the in-plane direction), The actual maximum tilt angle is small, so viewing angle characteristics are poor.

Furthermore, in Comparative Example 5 in which a forward-dispersing liquid crystal compound was used to form a liquid crystal alignment layer, an optical film having in-plane retardation with reverse wavelength dispersion was not obtained. Further, in Comparative Example 5, the substantial maximum tilt angle in the composite liquid crystal layer was much smaller than the substantial maximum tilt angle in the liquid crystal alignment layer. From this, it can be seen that in the liquid crystal alignment layer using the para-dispersive liquid crystal compound, the tilt of the molecules of the reverse-dispersive liquid crystal compound cannot be promoted in the liquid crystal inclined layer using the reverse-dispersive liquid crystal compound.

In contrast, from Table 1, it can be seen that in the examples, good results were obtained with respect to the alignment defects, the inverse wavelength dispersion, and the viewing angle characteristics.

From the above results, it was confirmed that by the present invention, it is possible to obtain an optical film having in-plane retardation with inverse wavelength dispersion, which can suppress the occurrence of alignment defects, and has excellent viewing angle characteristics.

In addition, in the above-mentioned examples, the results were all good in the surface state. From this, it was confirmed that the optical film provided with the composite liquid crystal layer which has a favorable surface state can be obtained by this invention.

100‧‧‧LCD alignment layer

100U‧‧‧Special surface

200‧‧‧ Optical Film

210‧‧‧LCD tilt layer

220‧‧‧ composite liquid crystal layer

300‧‧‧Layer of composition of orientation layer

300U‧‧‧Air interface

310‧‧‧ Molecules of liquid crystal compounds with reverse dispersion

320‧‧‧ Molecules of liquid crystal compounds with reverse dispersion

330‧‧‧ Molecules for reverse dispersion liquid crystalline compounds

340‧‧‧Fluorine surfactant

400‧‧‧LCD alignment layer

<FIG. 1> FIG. 1 is a schematic cross-sectional view illustrating a liquid crystal alignment layer related to an embodiment of the present invention.

<FIG. 2> FIG. 2 is a schematic cross-sectional view illustrating an optical film related to an embodiment of the present invention.

<Figure 3> Figure 3 is a graph plotting the retardation ratio R (θ) / R (0 °) of a related example liquid crystal alignment layer with respect to the incident angle θ.

<Fig. 4> Fig. 4 is a schematic cross-sectional view showing a layer body of an alignment layer composition obtained during the manufacturing process of a liquid crystal alignment layer related to an implementation mode.

<FIG. 5> FIG. 5 is a perspective view for explaining the measurement direction when measuring the retardation of the liquid crystal alignment layer from the oblique direction.

Claims (10)

A liquid crystal alignment layer is formed of a cured product of an alignment layer composition including "a liquid crystal compound capable of exhibiting reverse wavelength dispersion birefringence" and a "fluorine-containing surfactant", and includes an alignment state A liquid crystal alignment layer on which the molecules of the liquid crystal compound are fixed; wherein at least a part of the molecules of the liquid crystal compound included in the liquid crystal alignment layer is inclined with respect to a layer plane of the liquid crystal alignment layer; the liquid crystal alignment layer has an X-ray transmission Surfaces where the ratio of the surface fluorine atomic weight M _F [mole%] measured by photoelectron spectroscopy to the thickness T [μm] of the liquid crystal alignment layer M _F / T is 3.0 or more and less than 16.0; The thickness T is 2.5 μm or less. The liquid crystal alignment layer according to claim 1, wherein a substantial maximum tilt angle of a molecule of the liquid crystal compound contained in the liquid crystal alignment layer is 26 ° or more and 60 ° or less. An optical film comprising: the liquid crystal alignment layer according to claim 1 or 2; and a liquid crystal tilting layer formed of a cured product of a liquid crystal compound-containing tilting layer composition, wherein the liquid crystal compound is visually compatible with the foregoing The liquid crystal compound contained in the alignment layer composition has the same or different reverse wavelength dispersion birefringence; wherein the liquid crystal inclined layer is directly connected to the surface of the liquid crystal alignment layer. The optical film according to claim 3, wherein the in-plane retardation of the aforementioned optical film with a measurement wavelength of 590 nm is 100 nm or more and 180 nm or less. A method for manufacturing a liquid crystal alignment layer, comprising the steps of: forming a layer body of an alignment layer composition containing a birefringent liquid crystal compound exhibiting reverse wavelength dispersion and a fluorine atom-containing surfactant; and forming the alignment layer. A step of orienting the liquid crystal compound contained in the layer body of the material; and a step of curing the layer of the alignment layer composition to obtain a liquid crystal alignment layer; wherein at least a part of the liquid crystal compound contained in the liquid crystal alignment layer is The molecules are inclined with respect to the layer plane of the liquid crystal alignment layer, and the liquid crystal alignment layer has a surface fluorine atom amount M _F [mole%] measured by X-ray photoelectron spectroscopy and a thickness T [μm] of the liquid crystal alignment layer. Surfaces where the ratio M _F / T is 3.0 or more and less than 16.0; the thickness T of the liquid crystal alignment layer is 2.5 μm or less. A method for manufacturing an optical film, comprising: a step of directly forming a layer body including a liquid crystal compound-containing inclined layer composition on the aforementioned surface of the liquid crystal alignment layer according to claim 1 or 2, wherein the liquid crystal compound may be The step of orienting the liquid crystal compound contained in the layer body of the inclined layer composition, and developing the birefringence of reverse wavelength dispersion that is the same as or different from the liquid crystal compound contained in the alignment layer composition; and A step of curing the layer of the inclined layer composition to obtain a liquid crystal inclined layer. The method for manufacturing an optical film according to claim 6, wherein the step of directly forming a layer body of the inclined layer composition on the surface of the liquid crystal alignment layer includes not subjecting the surface of the liquid crystal alignment layer to a rubbing treatment, that is, Forming the layer body of the inclined layer composition directly on the surface of the liquid crystal alignment layer. A 1/4 wavelength plate comprising the liquid crystal alignment layer according to claim 1 or 2, or the optical film according to claim 3 or 4. A polarizing plate comprising the liquid crystal alignment layer according to claim 1 or 2, or the optical film according to claim 3 or 4. An organic electroluminescence display panel comprising a liquid crystal alignment layer according to claim 1 or 2, or an optical film according to claim 3 or 4.