JPWO2019240048A1 - Method for manufacturing optically anisotropic layer - Google Patents

Abstract

The present invention provides a method for producing an optically anisotropic layer, which has excellent durability and film contrast and can produce an image display device having excellent panel contrast. The method for producing an optically anisotropic layer of the present invention includes a step A of forming an uncured layer containing a polymerizable liquid crystal compound, a step B of heat-treating the uncured layer to form a nematic phase, and the above. The uncured layer on which the nematic phase is formed is subjected to a cooling treatment to form a smectic phase, and the uncured layer on which the smectic phase is formed is subjected to a first exposure treatment to form a semi-cured layer. It includes a step D and a step E in which the semi-cured layer is subjected to a second exposure treatment under a temperature condition higher than the temperature at the time of the first exposure treatment to form an optically anisotropic layer.

Description

The present invention relates to a method for producing an optically anisotropic layer.

Optical films such as adaptive optics sheets and retardation films are used in various image display devices for image tinting elimination and / or viewing angle enlargement.
Conventionally, a stretched birefringent film has been used as an optical film, but in recent years, an optically anisotropic layer formed by using a liquid crystal compound has been proposed in place of the stretched birefringent film.

For example, Patent Document 1 discloses a method for producing an optically anisotropic layer that is immobilized with a smectic phase. In the production method of Patent Document 1, an optically anisotropic layer is produced on an uncured layer made of a polymerizable liquid crystal composition through a heating step, a cooling heating step, and a polymerization step (claim 1).

JP-A-2017-068005

The optically anisotropic layer is often used by being incorporated in electronic devices. Therefore, the optically anisotropic layer is required to have durability that can exhibit stable performance for a long period of time even in a harsh environment such as a high temperature.
Further, when an optically anisotropic layer is formed directly on the polarizer or via another layer (for example, an alignment film) from the viewpoint of thinning, the optically anisotropic layer has excellent contrast (hereinafter, "film"). "Contrast" is also required.
Further, when an image display device using a polarizing plate including a polarizer and an optically anisotropic layer is manufactured, excellent contrast (hereinafter, abbreviated as "panel contrast") is required for the manufactured image display device. Has been done.

Therefore, it is an object of the present invention to provide a method for producing an optically anisotropic layer, which has excellent durability and film contrast and can produce an image display device having excellent panel contrast.

As a result of diligent studies to solve the above problems, the present inventors have found that the above problems can be solved by the following configuration.

[1]
Step A of forming an uncured layer containing a polymerizable liquid crystal compound,
Step B, in which the uncured layer is heat-treated to form a nematic phase,
Step C of forming a smectic phase by subjecting the uncured layer on which the nematic phase is formed to a cooling treatment,
Step D, in which the uncured layer having the smectic phase formed is subjected to the first exposure treatment to form a semi-cured layer,
Production of an optically anisotropic layer having a step E of performing a second exposure treatment on the semi-cured layer to form an optically anisotropic layer under a temperature condition higher than the temperature at the time of the first exposure treatment. Method.
[2]
The method for producing an optically anisotropic layer according to [1], wherein the temperature lowering rate of the uncured layer in the step C is 1 to 100 ° C./min.
[3]
The method for producing an optically anisotropic layer according to [1] or [2], wherein the temperature lowering rate of the uncured layer in the step C is 1 to 60 ° C./min.
[4]
The method for producing an optically anisotropic layer according to any one of [1] to [3], wherein the temperature of the uncured layer gradually decreases in the step C.
[5]
The method for producing an optically anisotropic layer according to any one of [1] to [4], wherein the light used in the first exposure treatment is ultraviolet rays.
[6]
The method for producing an optically anisotropic layer according to any one of [1] to [5], wherein the exposure amount in the first exposure process is 1 to 60 mJ / cm ^2.
[7]
The method for producing an optically anisotropic layer according to any one of [1] to [6], wherein the exposure amount in the first exposure process is 10 to 30 mJ / cm ^2.
[8]
The method for producing an optically anisotropic layer according to any one of [1] to [7], wherein the temperature during the second exposure treatment is higher than the phase transition temperature between the smectic phase and the nematic phase of the polymerizable liquid crystal compound. ..
[9]
The method for producing an optically anisotropic layer according to any one of [1] to [8], wherein the difference between the temperature during the first exposure treatment and the temperature during the second exposure treatment is 20 ° C. or higher. ..
[10]
The method for producing an optically anisotropic layer according to any one of [1] to [9], wherein the difference between the temperature during the first exposure treatment and the temperature during the second exposure treatment is 40 ° C. or higher. ..
[11]
The method for producing an optically anisotropic layer according to any one of [1] to [10], wherein the uncured layer contains an oxime ester-based polymerization initiator.

According to the present invention, it is possible to provide a method for producing an optically anisotropic layer having excellent durability and film contrast and capable of producing an image display device having excellent panel contrast.

Hereinafter, the present invention will be described in detail.
The description of the constituent elements described below may be based on typical embodiments of the present invention, but the present invention is not limited to such embodiments.
In the present specification, the numerical range represented by using "~" means a range including the numerical values before and after "~" as the lower limit value and the upper limit value.
When referring to the temperature of a layer (such as an uncured layer described later) in the present specification, it is intended that the temperature of the surface of the layer is the temperature measured by a radiation thermometer.
In the present specification, the smectic phase refers to a state in which molecules aligned in one direction have a layered structure, and the nematic phase means a state in which the constituent molecules have an orientation order but a three-dimensional positional order. The state of not having it.
In the present specification, the phase transition temperature is determined by observing the uncured layer formed on the alignment film while heating or cooling the uncured layer using a central processor FP90 (Mettler TORDO) and an optical microscope. The temperature at which the change occurred was defined as the phase transition temperature.
The uncured layer will be described later.

In the present invention, Re (λ) and Rth (λ) represent in-plane retardation and thickness direction retardation at wavelength λ, respectively. For example, Re (450) represents in-plane retardation at a wavelength of 450 nm. Unless otherwise specified, the wavelength λ is 550 nm.
In the present invention, Re (λ) and Rth (λ) are values measured at a wavelength λ in AxoScan OPMF-1 (manufactured by Optoscience). By inputting the average refractive index ((nx + ny + nz) / 3) and film thickness (d (μm)) in AxoScan,
Slow phase axial direction (°)
Re (λ) = R0 (λ)
Rth (λ) = ((nx + ny) /2-nz) × d
Is calculated.
Unless otherwise specified, R0 (λ) is displayed as a numerical value calculated by AxoScan OPMF-1, but means Re (λ).

In the present specification, the refractive indexes nx, ny, and nz are measured using an Abbe refractive index (NAR-4T, manufactured by Atago Co., Ltd.) and a sodium lamp (λ = 589 nm) as a light source. Further, when measuring the wavelength dependence, it can be measured with a multi-wavelength Abbe refractometer DR-M2 (manufactured by Atago Co., Ltd.) in combination with an interference filter.
In addition, the values in the Polymer Handbook (JOHN WILEY & SONS, INC) and the catalogs of various optical films can be used. The values of the average refractive index of the main optical films are illustrated below: cellulose acylate (1.48), cycloolefin polymer (1.52), polycarbonate (1.59), polymethylmethacrylate (1.49), And polystyrene (1.59).

Further, in the present specification, the bonding direction of the divalent group (for example, -CO-O-) described is not particularly limited, and for example, L ¹ in the general formula (W) described later is -CO-O. In the case of −, if the ^{position bonded to the P 1} side is * 1 and the position bonded to the Sp ¹ side is * 2, L ¹ can be * 1-CO-O- * 2. Often, it may be * 1-O-CO- * 2.

[Manufacturing method of optically anisotropic layer]
The method for producing an optically anisotropic layer of the present invention has the following steps A to E.
Step A: A step of forming an uncured layer containing a polymerizable liquid crystal compound (layer forming step).
Step B: A step B (nematic phase forming step) in which the uncured layer is heat-treated to form a nematic phase.
Step C: A step (cooling step) of forming a smectic phase by subjecting the uncured layer on which the nematic phase is formed to a cooling treatment.
Step D: A step of subjecting the uncured layer on which the smectic phase is formed to a first exposure treatment to form a semi-cured layer (first polymerization step).
Step E: Under a temperature condition higher than the temperature at the time of the first exposure treatment, the semi-cured layer is subjected to the second exposure treatment to form an optically anisotropic layer (second polymerization step).

The reason why the problem of the present invention can be solved by adopting such a configuration is not necessarily clear, but the present inventors consider as follows.
First, in the present invention, the uncured layer, which is cooled to the phase transition temperature between the smectic phase and the nematic phase and is in the state of the smectic phase, is subjected to the first exposure treatment to obtain excellent orientation of the smectic phase. It can be fixed, and the packing of the molecules of the finally obtained optically anisotropic layer is good. Therefore, the optically anisotropic layer of the present invention has excellent film contrast, and an image display device having excellent panel contrast can be obtained when used by incorporating it into an image display device.
Further, after the uncured layer is made into a semi-cured layer by the first exposure treatment, the semi-cured layer obtained at a higher temperature than the first exposure treatment is subjected to the second exposure treatment, thereby simply performing the first exposure treatment. It is considered that an optically anisotropic layer having a higher polymerization rate and excellent durability was obtained as compared with the case where the exposure was continued at the temperature in one exposure treatment.
Hereinafter, each step of the method for producing an optically anisotropic layer of the present invention will be described in detail.

[Manufacturing process of optically anisotropic layer]
<Step A (layer formation step)>
Step A (layer formation step) is a step of forming an uncured layer containing a polymerizable liquid crystal compound.
The uncured layer is a layer containing a polymerizable liquid crystal compound and not subjected to a curing treatment such as a first exposure treatment and a second exposure treatment described later. As will be described later, in the uncured layer, the nematic phase and the smectic phase are shown in this order on the lower temperature side than the isotropic phase.

When forming the uncured layer, it is preferable to form the uncured layer by using a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound. More specifically, for the uncured layer, for example, it is preferable to apply a polymerizable liquid crystal composition on a substrate to form the uncured layer. Examples of the base material include a support and a polarizer. An alignment film may be further arranged on the support.
Each component contained in the polymerizable liquid crystal composition will be described in detail later.
The method for applying the polymerizable liquid crystal composition is not particularly limited, and a known method can be adopted. For example, a screen printing method, a dip coating method, a spray coating method, a spin coating method, an inkjet method, a gravure offset printing method, and a flexographic printing method can be mentioned.
After applying the polymerizable liquid crystal composition, a drying treatment for removing the solvent may be carried out, if necessary.
The coating amount of the polymerizable liquid crystal composition may be appropriately adjusted according to the desired thickness of the optically anisotropic layer. For example, the thickness of the uncured layer in the state where the solvent or the like is removed is preferably 0.1 to 10 μm, and more preferably 0.5 to 5 μm.

<Step B (nematic phase forming step)>
Step B (nematic phase forming step) is a step of heat-treating the uncured layer to form a nematic phase.
The procedure of the nematic phase forming step is not particularly limited as long as the uncured layer can be made into a nematic phase by heating the temperature of the uncured layer to a temperature equal to or higher than the phase transition temperature between the smectic phase and the nematic phase.

The temperature of the uncured layer (first heating temperature) adjusted by the heating is equal to or higher than the phase transition temperature between the smectic phase and the nematic phase. The first heating temperature is preferably 0 to 83 ° C. higher, more preferably 2 to 53 ° C. higher, and further 2 to 37 ° C. higher than the phase transition temperature between the smectic phase and the nematic phase at the time of temperature rise. preferable.
Further, the uncured layer is preferably held for a certain period of time in a state where the nematic phase is formed. Such a holding time is preferably 1 second to 10 minutes, more preferably 5 seconds to 5 minutes or less, and even more preferably 5 to 30 seconds. During the holding time, the temperature of the uncured layer is preferably maintained within a range of ± 5 ° C. from the first heating temperature.

The means for adjusting the temperature of the uncured layer is not particularly limited, and for example, a hot plate may be used or an oven may be used. The same applies to the temperature control of each layer described in the following steps.

<Process C (cooling process)>
Step C (cooling step) is a step of forming a smectic phase by performing a cooling treatment on the uncured layer in which the nematic phase is formed by step B (nematic phase forming step).
The temperature (cooling temperature) of the uncured layer that has been cooled in the cooling step is not particularly limited as long as the uncured layer can form a smectic phase, and is higher than the temperature at which crystals start to form in the uncured layer. Is preferable. The cooling temperature is preferably 0 to 60 ° C. lower, more preferably 2 to 25 ° C. lower, and even more preferably 5 to 15 ° C. lower than the phase transition temperature between the smectic phase and the nematic phase during temperature reduction.
The temperature lowering rate (lowering rate) of the uncured layer during cooling in the cooling step is 0.5 to 200 ° C. from the viewpoint that an image display device having better film contrast and panel contrast of the optically anisotropic layer can be obtained. / Minute is preferable, 1 to 100 ° C./min is more preferable, 1 to 80 ° C./min is further preferable, and 1 to 60 ° C./min is particularly preferable.
The temperature lowering rate is obtained by dividing the temperature difference between the first heating temperature and the cooling temperature by the time taken from the start of the cooling process to the arrival at the cooling temperature.
Further, in the cooling step, it is preferable that the temperature of the uncured layer gradually decreases. In addition, "the temperature gradually decreases" means that the temperature of the uncured layer is decreasing as a whole in the cooling step. In other words, it is intended that there will be no significant temperature rise in the uncured layer from the onset of temperature reduction until the cooling temperature is reached.

The cooling treatment method is not particularly limited, and it is sufficient that the uncured layer forming the nematic layer can be used as the smectic phase. For example, the uncured layer forming the nematic layer is placed on a hot plate set higher than the phase transition temperature between the crystalline phase and the smectic phase and lower than the phase transition temperature between the smectic phase and the nematic phase. Then, a method of forming a smectic phase in the uncured layer can be mentioned.

<Step D (first polymerization step)>
Step D (first polymerization step) is a step of subjecting the uncured layer having the smectic phase formed in step C to the first exposure treatment to form a semi-cured layer.
At the time of performing the first exposure treatment, it is preferable that a smectic phase is formed in the entire uncured layer.

The light used in the first exposure treatment is preferably ultraviolet rays, and the above-mentioned ultraviolet rays are preferably ultraviolet rays containing light having a wavelength of 365 nm.
Examples of the exposure light source include metal halide lamps, mercury lamps (medium pressure mercury lamps, high pressure mercury lamps, ultrahigh pressure mercury lamps, etc.), xenon lamps, carbon arc lamps, fluorescent lamps (fluorescent lamps for ultraviolet rays, etc.), LEDs (LEDs: light emitting dimension, etc.). (Ultraviolet LED, etc.) and LD (LD: laser diode, ultraviolet LD, etc.) can be mentioned.
The wavelength range to irradiate the light obtained from the exposure light source may be limited by using an interference filter, a color filter, or the like. Further, the light from these exposure light sources may be polarized by using a polarizing filter, a polarizing prism, or the like.
The amount of exposure in the first exposure treatment is not particularly limited, and as will be described later, it is sufficient that some polymerizable groups contained in the polymerizable liquid crystal compound can be polymerized to form a semi-cured layer. Above all, the exposure amount (preferably wavelength) in the first exposure process is excellent in that the durability and film contrast of the optically anisotropic layer and the panel contrast when the optically anisotropic layer is incorporated in the image display device are well-balanced and excellent. integrated exposure amount 300～390Nm) is preferably 0.5~100mJ / cm ^2, more preferably 1~60mJ / cm ^2, more preferably 10~30mJ / cm ^2.
Further, the first exposure treatment is preferably carried out in an atmosphere of an inert gas such as nitrogen gas from the viewpoint of advancing the uniform polymerization reaction.

The semi-cured layer is obtained by the first exposure treatment described above. The semi-cured layer is a layer obtained by polymerizing a part of the polymerizable groups contained in the polymerizable liquid crystal compound, and the polymerizable groups derived from the polymerizable liquid crystal compound remain in the semi-cured layer. Above all, the residual ratio of the polymerizable group derived from the polymerizable liquid crystal compound after the first exposure treatment is preferably 10% or more, more preferably 20% or more. The upper limit is that the residual ratio of the polymerizable group after the first exposure treatment is preferably 90% or less, more preferably 80% or less, in order to improve the durability after the second exposure treatment.
The residual ratio is the amount of the polymerizable group derived from the polymerizable liquid crystal compound in the semi-cured layer after the first exposure treatment and the polymerizable group derived from the polymerizable liquid crystal compound in the uncured layer before the first exposure treatment. Calculated by comparing with the amount. Specifically, an infrared spectrophotometer shows a peak derived from a polymerizable group in the uncured layer and a peak derived from a structure (for example, a carbonyl group) in a polymerizable liquid crystal compound whose intensity does not change before and after exposure. The ratio X of is calculated. Similarly, the ratio Y of the peak derived from the polymerizable group in the semi-cured layer and the peak derived from the structure (for example, carbonyl group) in the polymerizable liquid crystal compound whose intensity does not change before and after exposure is calculated. Next, the residual rate can be calculated by the formula: ratio Y / ratio X × 100.

<Step E (second polymerization step)>
Step E (second polymerization step) is a step of subjecting the semi-cured layer to the second exposure treatment under a temperature condition higher than the temperature at the time of the first exposure treatment to form an optically anisotropic layer.
The temperature condition higher than the temperature at the time of the first exposure treatment means that the temperature of the semi-cured layer at the time of the second exposure treatment is higher than the temperature of the uncured layer at the time of the first exposure treatment. There is no limit as long as the environment is high.
Usually, in order to achieve the above temperature conditions, in the second polymerization step, the semi-cured layer obtained through the first polymerization step is heat-treated (second heat treatment). The second exposure treatment may be started at the same time as the second heat treatment, or may be carried out after the semi-cured layer reaches a predetermined temperature by the second heat treatment.
The second exposure treatment may be carried out while raising the temperature of the semi-cured layer, or may be carried out while keeping the temperature of the semi-cured layer constant.

The temperature of the semi-cured layer that rises due to the second heat treatment (the temperature difference between the semi-cured layers before and after the second heat treatment. In other words, the difference between the temperature during the first exposure treatment and the temperature during the second exposure treatment). Is preferably 10 ° C. or higher, more preferably 20 ° C. or higher, still more preferably 40 ° C. or higher, from the viewpoint of more excellent durability of the obtained optically anisotropic layer. The upper limit is preferably 160 ° C. or lower.
The temperature of the semi-cured layer during the second exposure treatment (second heating temperature) is the difference between the smectic phase and the nematic phase when the temperature of the uncured layer is raised, because the obtained optically anisotropic layer is more durable. It is preferably above the phase transition temperature.
The heating rate (heating rate) when the semi-cured layer is heated in the second heat treatment is preferably 0.5 to 250 ° C./min, more preferably 50 to 200 ° C./min, and 75 to 150 ° C./min. Minutes are even more preferred.
The temperature rise rate is obtained by dividing the temperature difference between the semi-cured layers before and after the second heat treatment by the time required for the second heat treatment.

The light used in the second exposure treatment is preferably ultraviolet rays, and the above-mentioned ultraviolet rays are preferably ultraviolet rays containing light having a wavelength of 365 nm.
As the exposure light source, the same exposure light source as mentioned in the description of the first exposure process is exemplified.
The wavelength range to irradiate the light obtained from the exposure light source may be limited by using an interference filter, a color filter, or the like. Further, the light from these exposure light sources may be polarized by using a polarizing filter, a polarizing prism, or the like.
Exposure amount in the second exposure process (integrated exposure amount of preferably wavelength 300～390Nm) is preferably 100~10000mJ / cm ^2, more preferably 200~5000mJ / cm ^2, more preferably 400~1500mJ / cm ^2.
Further, the second exposure treatment is preferably carried out in an atmosphere of an inert gas such as nitrogen gas from the viewpoint of advancing the uniform polymerization reaction.

The optically anisotropic layer obtained by performing the second exposure treatment does not substantially contain a polymerizable group derived from a polymerizable liquid crystal compound. The above "substantially" means that the residual ratio of the polymerizable group derived from the polymerizable liquid crystal compound is 5% or less. The residual ratio is the amount of the polymerizable group derived from the polymerizable liquid crystal compound in the optically anisotropic layer and the amount of the polymerizable group derived from the polymerizable liquid crystal compound in the uncured layer before the first exposure treatment. Calculated by comparison. Specifically, a method using the above-mentioned infrared spectrophotometer can be mentioned.

[Polymerizable liquid crystal composition]
In the production method of the present invention, it is preferable to use a polymerizable liquid crystal composition.
Hereinafter, the polymerizable liquid crystal composition will be described.

<Polymerizable liquid crystal compound>
The polymerizable liquid crystal composition contains a polymerizable liquid crystal compound.
As one or more of the polymerizable liquid crystal compounds used here, a polymerizable liquid crystal compound capable of expressing a nematic phase and a smectic phase is preferable.
The polymerizable liquid crystal composition may contain other polymerizable liquid crystal compounds other than the polymerizable liquid crystal compound capable of expressing the nematic phase and the smectic phase, but the polymerizable liquid crystal composition as a whole expresses the nematic phase and the smectic phase. It is necessary to be able to form an uncured layer that can be formed.

The polymerizable liquid crystal compound is a liquid crystal compound having at least one polymerizable group.
Generally, liquid crystal compounds can be classified into rod-shaped type and disk-shaped type according to their shape. In addition, there are low molecular weight and high molecular weight types, respectively. A polymer generally refers to a compound having a degree of polymerization of 100 or more (Polymer Physics / Phase Transition Dynamics, Masao Doi, p. 2, Iwanami Shoten, 1992).
As the polymerizable liquid crystal compound, any liquid crystal compound can be used as long as it has a polymerizable group and can form an uncured layer capable of expressing a smectic phase. Above all, it is preferable to use a rod-shaped polymerizable liquid crystal compound.

The polymerizable liquid crystal compound preferably has two or more polymerizable groups in one molecule. When two or more kinds of polymerizable liquid crystal compounds are used, it is preferable that at least one kind of polymerizable liquid crystal compound has two or more polymerizable groups in one molecule.
After the liquid crystal compound is fixed by polymerization, it is no longer necessary to exhibit liquid crystal properties, but the layer thus formed may be referred to as a liquid crystal layer for convenience.

The type of the polymerizable group contained in the polymerizable liquid crystal compound is not particularly limited, and a functional group capable of an addition polymerization reaction is preferable, and a polymerizable ethylenically unsaturated group or a ring-polymerizable group is more preferable. For example, a (meth) acryloyl group, a vinyl group, a styryl group, an allyl group, an epoxy group, or an oxetane group is preferable, and a (meth) acryloyl group is more preferable because the polymerization reaction is fast.

(Polymerizable liquid crystal compound capable of expressing a smectic phase)
Examples of the polymerizable liquid crystal compound capable of expressing the smectic phase are described in JP-A-2016-51178, JP-A-2008-214269, JP-A-2008-19240, and JP-A-2006-276821. Examples include compounds.

Further, as the rod-shaped polymerizable liquid crystal compound, a polymerizable liquid crystal compound having a maximum absorption wavelength in the wavelength range of 330 to 380 nm is preferable.
Further, as the rod-shaped polymerizable liquid crystal compound, a reverse wavelength dispersible polymerizable liquid crystal compound is preferable.
Here, in the present specification, the fact that the polymerizable liquid crystal compound has inverse wavelength dispersibility means that the retardation film (optically anisotropic layer or the like) produced by using such a polymerizable liquid crystal compound has a specific wavelength (optically anisotropic layer or the like). When the in-plane retardation (Re) value in the visible light range) is measured, the Re value becomes equal or higher as the measurement wavelength increases.
For example, a polymerizable liquid crystal compound capable of forming an optically anisotropic layer satisfying the following formula is preferable.
Re (450) / Re (550) <1.00

Among them, as the polymerizable liquid crystal compound, a compound represented by the general formula (W) is preferable.
P ^1- L ^1- Sp ^1- L ^2- (-A ^1- L ^3- ) _m -MG- (-L ^4- A ^2- ) _n- L ^{5- Sp 2- L 6-} P ² (W)

In the general formula (W), m and n each independently represent an integer of 1 to 3.

In the general formula (W), L ¹ , L ² , L ³ , L ⁴ , L ⁵ , and L ⁶ each independently represent a single bond or a divalent linking group.
As the divalent linking ^{group, -CO-O -, - C} (= S) O -, - CR 1 R 2 -, - CR 1 R 2 -CR 3 R 4 -, - O-CR 1 R 2 ^{-, - CR 1 R 2 -O} -CR 3 R 4 -, - CO-O-CR 1 R 2 -, - O-CO-CR 1 R 2 -, - CR 1 R 2 -O-CO-CR 3 ^{R 4 -, - CR 1 R} 2 -CO-O-CR 3 R 4 -, - NR 1 -CR 2 R 3 -, or, -CO-NR ¹ - is preferred. R ¹ , R ² , R ³ and R ⁴ independently represent a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 4 carbon atoms.
When a ^{plurality of L 3s} are present, the plurality of L ^3s may be the same or different from each other. If L ⁴ there are a plurality, or different is L ⁴ there are a plurality of each identical.

In the above general formula (W), A ¹ and A ² are independently aromatic ring groups having 6 or more carbon atoms or alicyclic hydrocarbon groups having 5 or more carbon atoms (preferably 5 to 8 carbon atoms). Represents.
_{One or more of -CH 2-} constituting the alicyclic hydrocarbon group may be substituted with -O-, -S- or -NH-.
If the A ¹ there are plural, A ¹ may be different from each other in the same presence of a plurality. If A ² there are a plurality, or different is A ² there are a plurality of each identical.

As ^{the alicyclic hydrocarbon group having 5 or more carbon atoms represented by A 1} and A ² , a 5-membered ring or a 6-membered ring group is preferable. The alicyclic hydrocarbon group may be saturated or unsaturated, but a saturated alicyclic hydrocarbon group is preferable.
Examples of the alicyclic hydrocarbon group include a cyclohexane ring group (cyclohexane-1,4-diyl group, etc.) and a cyclohexene ring group.
Further, as the alicyclic hydrocarbon group, for example, the description in paragraph [0078] of JP2012-21068A can be referred to, and this content is incorporated in the present specification.

Examples ^{of the aromatic ring having 6 or more carbon atoms shown in A 1} and A ² include an aromatic hydrocarbon ring such as a benzene ring, a naphthalene ring, an anthracene ring, and a phenanthroline ring; a furan ring, a pyrrole ring, and a thiophene. Aromatic heterocycles such as a ring, a pyridine ring, a thiazole ring, and a benzothiazole ring; Of these, a benzene ring (for example, a 1,4-phenylene group or the like) is preferable.

In the general formula (W), Sp ¹ and Sp ² are independently single-bonded, linear or branched alkylene groups having 1 to 12 carbon atoms, or linear or branched having 1 to 12 carbon atoms, respectively. _{A divalent linking group in which one or more of -CH 2-} constituting the alkylene group in the form is substituted with -O-, -S-, -NH-, -N (Q)-, or -CO-. Represent. Q represents a substituent (alkyl group, alkoxy group, halogen atom, etc.).

As the ^{linear or branched alkylene group having 1 to 12 carbon atoms represented by Sp 1} and Sp ² , for example, a methylene group, an ethylene group, a propylene group, a butylene group and the like are preferable.

In the general formula (W), P ¹ and P ² each independently represent a monovalent organic group, ^{and at least one of P 1} and P ² represents a polymerizable group. However, when MG is an aromatic ring represented by the general formula (Ar-3) described later, at least one of ^{P 1} and P ^{2 and P 3} and P ^{4 in} the general formula (Ar-3) is polymerized. Represents a sex group.

The ^{polymerizable group represented by P 1} and P ² is not particularly limited, and a radical polymerizable group or a cationically polymerizable group is preferable.
As the radically polymerizable group, a generally known radically polymerizable group can be used. For example, acryloyl group and methacryloyl group can be mentioned. In this case, the polymerization rate is generally high for acryloyl groups, and acryloyl groups are preferable from the viewpoint of improving productivity. Further, the methacryloyl group can also be used as the polymerizable group of the highly birefringent liquid crystal.
As the cationically polymerizable group, a generally known cationically polymerizable group can be used. For example, an alicyclic ether group, a cyclic acetal group, a cyclic lactone group, a cyclic thioether group, a spiroorthoester group, a vinyloxy group and the like can be mentioned. Of these, an alicyclic ether group or a vinyloxy group is preferable, and an epoxy group, an oxetanyl group, or a vinyloxy group is more preferable.
Examples of particularly preferable polymerizable groups include the following.
In the following polymerizable groups, black circles represent bond positions.

In the general formula (W), MG represents any aromatic ring selected from the group consisting of the groups represented by the following general formulas (Ar-1) to (Ar-5). In the following general formulas (Ar-1) to (Ar-5), * 1 ^{represents the bonding position with L 3} and * 2 represents the bonding position with L ⁴ .

Here, in the above general formula (Ar-1), Q ¹ represents N or CH, Q ² represents -S-, -O-, or -N (R ⁵ )-, and R ^{5 represents.} represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, Y ¹ may have a substituent, an aromatic hydrocarbon group having 6 to 12 carbon atoms, or aromatic having 3 to 12 carbon atoms Represents a heterocyclic group.
Examples of the alkyl group having 1 to 6 carbon atoms indicated by R ⁵ include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group and an n-pentyl group. Groups, n-hexyl groups and the like can be mentioned.
Examples of the aromatic hydrocarbon group having 6 to 12 carbon atoms indicated by Y ¹ include an aryl group such as a phenyl group, a 2,6-diethylphenyl group, and a naphthyl group.
Examples of the aromatic heterocyclic group having 3 to 12 carbon atoms indicated by Y ¹ include heteroaryl groups such as a thienyl group, a thiazolyl group, a frill group, and a pyridyl group.
Examples of the substituent that Y ¹ may have include an alkyl group, an alkoxy group, and a halogen atom.
As the alkyl group, for example, a linear, branched or cyclic alkyl group having 1 to 18 carbon atoms is preferable, and an alkyl group having 1 to 8 carbon atoms (for example, a methyl group, an ethyl group, a propyl group or an isopropyl group) is preferable. , N-butyl group, isobutyl group, sec-butyl group, t-butyl group, cyclohexyl group, etc.) is more preferable, an alkyl group having 1 to 4 carbon atoms is further preferable, and a methyl group or an ethyl group is particularly preferable.
As the alkoxy group, for example, an alkoxy group having 1 to 18 carbon atoms is preferable, and an alkoxy group having 1 to 8 carbon atoms (for example, a methoxy group, an ethoxy group, an n-butoxy group, a methoxyethoxy group, etc.) is more preferable. , Alkoxy groups having 1 to 4 carbon atoms are more preferable, and methoxy groups or ethoxy groups are particularly preferable.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like, and among them, a fluorine atom or a chlorine atom is preferable.

Further, in the above general formulas (Ar-1) to (Ar-5), Z ¹ , Z ² and Z ³ are independently hydrogen atoms and monovalent aliphatic hydrocarbon groups having 1 to 20 carbon atoms. Monovalent alicyclic hydrocarbon group with 3 to 20 carbon atoms, monovalent aromatic hydrocarbon group with 6 to 20 carbon atoms, halogen atom, cyano group, nitro group, -NR ⁶ R ⁷ , or -SR It represents ^8, R 6 to R ⁸ each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, ^{Z 1} and ^{Z 2} may form an aromatic ring bonded to each other.
As the monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, an alkyl group having 1 to 15 carbon atoms is preferable, an alkyl group having 1 to 8 carbon atoms is more preferable, and a methyl group, an ethyl group, an isopropyl group, and tert are preferable. -Pentyl group (1,1-dimethylpropyl group), tert-butyl group, or 1,1-dimethyl-3,3-dimethyl-butyl group is more preferable, and methyl group, ethyl group, or tert-butyl group. Is particularly preferable.
Examples of the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecyl group, a methylcyclohexyl group, and the like. Monocyclic saturated hydrocarbon groups such as ethylcyclohexyl group; cyclobutenyl group, cyclopentenyl group, cyclohexenyl group, cycloheptenyl group, cyclooctenyl group, cyclodecenyl group, cyclopentadienyl group, cyclohexadienyl group, cyclooctadienyl group, And monocyclic unsaturated hydrocarbon groups such as cyclodecadien; bicyclo [2.2.1] heptyl group, bicyclo [2.2.2] octyl group, tricyclo [5.2.1.0 ^2,6 ] Decyl group, tricyclo [3.3.1.1 ^3,7 ] decyl group, tetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] Dodecyl group, polycyclic saturated hydrocarbon group such as adamantyl group; and the like.
Examples of the monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms include a phenyl group, a 2,6-diethylphenyl group, a naphthyl group, a biphenyl group and the like, and an aryl group having 6 to 12 carbon atoms. (Especially a phenyl group) is preferable.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like, and among them, a fluorine atom, a chlorine atom or a bromine atom is preferable.
On the other hand, ^{examples of the alkyl group having 1 to 6 carbon atoms represented by R 6 to} R ⁸ include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group and tert-butyl. Examples include a group, an n-pentyl group, an n-hexyl group and the like.

Further, in the above general formula (Ar-2) and ^{(Ar-3), A} 3 and ^{A 4} are each ^{independently, -O -, - N (R} 9) -, - S-, and, -CO- Represents a group selected from the group consisting of, where R ⁹ represents a hydrogen atom or substituent.
Examples of the substituent represented by R ⁹ include a group similar to the substituent that ^{Y 1} in the general formula (Ar-1) may have.

Further, in the above general formula (Ar-2), X represents a non-metal atom of Group 14 to 16 to which a hydrogen atom or a substituent may be bonded.
Examples of the non-metal atoms of Groups 14 to 16 indicated by X include an oxygen atom, a sulfur atom, a nitrogen atom having a substituent, and a carbon atom having a substituent. Examples of the substituent include a carbon atom having a substituent. , Alkyl group, alkoxy group, alkyl substituted alkoxy group, cyclic alkyl group, aryl group (for example, phenyl group, naphthyl group, etc.), cyano group, amino group, nitro group, alkylcarbonyl group, sulfo group, hydroxyl group, etc. Can be mentioned.

Further, in the above general formula (Ar-3), L ⁷ and L ⁸ are independently single-bonded, -CO-O-, -C (= S) O-, -CR ¹ R ^2- , -CR, respectively. ^{1 R 2 -CR 3 R 4 -} , - O-CR 1 R 2 -, - CR 1 R 2 -O-CR 3 R 4 -, - CO-O-CR 1 R 2 -, - O-CO-CR ^{1 R 2 -, - CR 1} R 2 -O-CO-CR 3 R 4 -, - CR 1 R 2 -CO-O-CR 3 R 4 -, - NR 1 -CR 2 R 3 -, or - Represents CO-NR ^1-. R ¹ , R ² , R ³ and R ⁴ independently represent a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 4 carbon atoms.

Further, in the above general formula (Ar-3), SP ³ and SP ⁴ are independently single-bonded, linear or branched alkylene groups having 1 to 12 carbon atoms, or 1 to 12 carbon atoms. _{One or more of -CH 2-} constituting a linear or branched alkylene group is substituted with -O-, -S-, -NH-, -N (Q)-, or -CO- 2 It represents a valent linking group and Q represents a substituent. Examples of the substituent include a group similar to the substituent that ^{Y 1} in the general formula (Ar-1) may have.

Further, in the above general formula (Ar-3), P ³ and P ⁴ each independently represent a monovalent organic group, and a polymerizable group is preferable. Examples of the polymerizable groups are as described in relation to P ¹ and P ² described above. However, as MG described above, when an aromatic ring represented by general formula (Ar-3), at least one of ^{P 3} and ^{P 4} in ^{P 1} and ^{P 2} and formula (Ar-3) Represents a polymerizable group.

Further, in the above general formulas (Ar-4) to (Ar-5), Ax has at least one aromatic ring selected from the group consisting of an aromatic hydrocarbon ring and an aromatic heterocycle, and has 2 to 30 carbon atoms. Represents an organic group of.
Further, in the above general formulas (Ar-4) to (Ar-5), Ay is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms which may have a substituent, or an aromatic hydrocarbon ring and an aromatic hydrocarbon ring. Represents an organic group having 2 to 30 carbon atoms and having at least one aromatic ring selected from the group consisting of aromatic heterocycles.
Here, the aromatic ring in Ax and Ay may have a substituent, or Ax and Ay may be bonded to form a ring.
Further, Q ³ represents a hydrogen atom or may have a substituent alkyl group having 1 to 6 carbon atoms.
Examples of Ax and Ay include the groups described in paragraphs [0039] to [0995] of Patent Document 3 (International Publication No. 2014/010325).
The alkyl group having 1 to 6 carbon atoms represented by ^{Q 3,} for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, n- butyl group, isobutyl group, sec- butyl group, tert- butyl radical, n -Pentyl group, n-hexyl group and the like can be mentioned, and examples of the substituent include a group similar to the substituent that ^{Y 1 in the above general formula (Ar-1) may have.}

Preferred examples of the liquid crystal compound represented by the general formula (W) are shown below, but the present invention is not limited to these liquid crystal compounds. The 1,4-cyclohexylene groups in the following formulas are all trans-1,4-cyclohexylene groups. Further, n in the following formula represents an integer of 1 to 12.

なお、上記式中、「＊」は結合位置を表す。

In the above formula, "*" represents the bonding position.

なお、上記式ＩＩ−２−８およびＩＩ−２−９中のアクリロイルオキシ基に隣接する基は、プロピレン基（メチル基がエチレン基に置換した基）を表し、メチル基の位置が異なる位置異性体の混合物を表す。

The group adjacent to the acryloyloxy group in the above formulas II-2-8 and II-2-9 represents a propylene group (a group in which a methyl group is replaced with an ethylene group), and the positions of the methyl groups are different. Represents a mixture of bodies.

The content of the polymerizable liquid crystal compound in the polymerizable liquid crystal composition is preferably 50 to 100% by mass, more preferably 60 to 98% by mass, and more preferably 65, based on the total mass of the liquid crystal compounds in the polymerizable liquid crystal composition. ~ 95% by mass is more preferable.
When the polymerizable liquid crystal composition also contains a non-polymerizable liquid crystal compound, the total mass of the liquid crystal compound is the mass including the mass thereof.
When two or more kinds of polymerizable liquid crystal compounds are used, the total content thereof is preferably within the above range.

The content of the polymerizable liquid crystal compound in the polymerizable liquid crystal composition is preferably 50 to 99.99% by mass, more preferably 65 to 99.9% by mass, based on the mass of the total solid content of the polymerizable liquid crystal composition. It is preferable, and 80 to 99.5% by mass is more preferable.
When two or more kinds of polymerizable liquid crystal compounds are used, the total content thereof is preferably within the above range.
The total solid content is intended as a component that forms an optically anisotropic layer, and does not contain a solvent. Further, if the component forms an optically anisotropic layer, it is regarded as a solid content even if the property is liquid.

<Photopolymerization initiator>
The polymerizable liquid crystal composition preferably contains a photopolymerization initiator.
The polymerization initiator used is preferably a photopolymerization initiator capable of initiating a polymerization reaction by irradiation with ultraviolet rays.
Examples of the photopolymerization initiator include an oxime ester-based polymerization initiator, an α-carbonyl-based polymerization initiator (for example, described in US Pat. Nos. 2,376,661 and 236,670), and an acyloin ether-based polymerization initiator (described in each specification of the same). For example, US Pat. No. 2,448,828 (described in US Pat. No. 2,448,828), α-carbohydrate-substituted aromatic acyloin-based polymerization initiator (for example, described in US Pat. No. 2,725,212), polynuclear quinone-based polymerization initiator (for example, US Pat. No. 3,406127). (No. 2951758), a polymerization initiator in combination with a triarylimidazole dimer and a p-aminophenyl ketone (for example, described in US Pat. No. 3,549,637), an acridin and a phenazine-based polymerization initiator (for example, described in US Pat. No. 3,549,678). For example, JP-A-60-105667, US Pat. No. 4,239,850 (described in US Pat. No. 4,239,850), an oxadiazole-based polymerization initiator (for example, described in US Pat. No. 4,212,970), and acylphosphine oxide-based polymerization initiator. Examples thereof include agents (described in, for example, Japanese Patent Publication No. 63-40799, Japanese Patent Application Laid-Open No. 5-29234, Japanese Patent Application Laid-Open No. 10-95788, Japanese Patent Application Laid-Open No. 10-29997) and the like.
Of these, an oxime ester-based polymerization initiator is preferable because curing proceeds uniformly when exposed and an optically anisotropic layer having more excellent orientation can be obtained.
The content of the photopolymerization initiator in the polymerizable liquid crystal composition is preferably 0.01 to 20% by mass, preferably 0.1 to 8% by mass, based on the total mass of the polymerizable liquid crystal compound in the polymerizable liquid crystal composition. % Is more preferable.
The polymerization initiator may be used alone or in combination of two or more.
When two or more kinds of polymerization initiators are used, the total content thereof is preferably within the above range.

<Surfactant>
The polymerizable liquid crystal composition preferably contains a surfactant from the viewpoint of keeping the surface on the air interface side when the uncured layer is formed smooth and obtaining an optically anisotropic layer having more excellent orientation.
As such a surfactant, a fluorine-based surfactant or a silicon-based surfactant is preferable because it has a high leveling effect on the amount of addition, and from the viewpoint of preventing crying (bloom, bleeding), the fluorine-based surfactant is active. The agent is more preferred.
Examples of the surfactant include the compounds described in paragraphs [0079] to [0102] of JP-A-2007-069471, and the general formula (I) described in JP-A-2013-047204. (In particular, the compounds described in paragraphs [0020] to [0032]), and the compounds represented by the general formula (I) described in JP2012-221306A (particularly, paragraphs [0022] to [0029]. ], A liquid crystal orientation promoter represented by the general formula (I) described in JP-A-2002-129162 (particularly paragraphs [0076] to [0078] and paragraphs [0082] to [0084]. ], And the compounds represented by the general formulas (I), (II) and (III) described in JP-A-2005-09948 (particularly in paragraphs [0092] to [0996]. The described compounds) and the like can be mentioned.

<Solvent>
The polymerizable liquid crystal composition may contain a solvent in order to improve the manufacturing suitability such as lowering the viscosity at the time of forming the uncured layer.
The solvent is not particularly limited, but is selected from at least one of the group consisting of ketones (including cyclic ketones such as cyclopentanone), esters, ethers, alcohols, alkanes, toluene, chloroform, and methylene chloride. Is preferable, and it is more preferably selected from at least one of the group consisting of ketones, esters, ethers, alcohols, and alcohols, and more preferably selected from at least one of the groups consisting of ketones, esters, ethers, and alcohols. Is even more preferable.

<Other ingredients>
The polymerizable liquid crystal compound may contain other components other than those described above.
As other components, for example, a thermal polymerization initiator may be contained.
In addition, for example, a chiral agent or the like may be used from the viewpoint of adjusting the orientation of the optically anisotropic layer.
Further, from the viewpoints of adjusting the viscosity, phase transition temperature, orientation uniformity, film physical characteristics of the optically anisotropic layer, and adjusting the optical characteristics of the polymerizable liquid crystal composition, a non-polymerizable liquid crystal compound is used. May be good. The non-polymerizable liquid crystal compound may be a low molecular weight liquid crystal compound. Further, the non-polymerizable liquid crystal compound may be a main chain type liquid crystal polymer or a side chain type liquid crystal polymer.
From the viewpoint of imparting pot life to the polymerizable liquid crystal composition and improving the durability of the optically anisotropic layer, a polymerization inhibitor, an antioxidant, an ultraviolet absorber and the like may be used.
Plasticizers, retardation modifiers, dichroic dyes, fluorescent dyes, photochromic dyes, thermochromic dyes, photoisomerizing materials, photodimerization from the viewpoints of further functioning, adjusting liquid physical properties, and adjusting film physical characteristics. Materials, nanoparticles, thixotropic agents and the like may be added.

The uncured layer formed by using such a polymerizable liquid crystal composition preferably has a phase transition temperature of 80 ° C. or lower between the smectic phase and the nematic phase, and for example, the film contrast and the panel contrast are better. From this point of view, it is more preferable that the temperature is 70 ° C. or higher and lower than 80 ° C.

[Optically anisotropic layer]
The thickness of the optically anisotropic layer produced by the production method of the present invention is not particularly limited, but is preferably 0.1 to 10 μm, more preferably 0.5 to 5 μm.
The optically anisotropic layer produced by the production method of the present invention is preferably a layer in which the smectic phase is immobilized.

A positive A plate is mentioned as a preferable mode of the optically anisotropic layer. To obtain a positive A plate, there is a method of horizontally orienting a rod-shaped polymerizable liquid crystal compound. Further, when the in-plane retardation Re (550) is 100 to 160 nm (preferably 120 to 150 nm), it can be suitably used as a positive uniaxial λ / 4 plate. Further, Re (550) can be used as a positive uniaxial λ / 2 plate in the range of 250 to 300 nm. Here, Re (550) represents the in-plane retardation of the optically anisotropic layer at a wavelength of 550 nm. The in-plane retardation value can be measured using AxoScan OPMF-1 (manufactured by Optoscience).

Another preferred mode of the optically anisotropic layer is a positive C plate. To obtain a positive C plate, there is a method of vertically orienting a rod-shaped polymerizable liquid crystal compound. The thickness direction retardation Rth (550) is, for example, 20 to 200 nm, and is preferably 50 to 120 nm from the viewpoint of imparting various optical compensation functions and / or viewing angle improving functions.

In addition, the optically anisotropic layer may be a negative A plate, a negative C plate, or the like.

In this specification, the A plate is defined as follows.
There are two types of A plates, a positive A plate (positive A plate) and a negative A plate (negative A plate), and the slow axis direction in the film plane (the direction in which the refractive index in the plane is maximized). ) Is nx, the refractive index in the direction orthogonal to the slow axis in the plane is ny, and the refractive index in the thickness direction is nz, the positive A plate satisfies the relationship of the equation (A1). The negative A plate satisfies the relation of the formula (A2). The positive A plate shows a positive value for Rth, and the negative A plate shows a negative value for Rth.
Equation (A1) nx> ny≈nz
Equation (A2) ny <nx≈nz
The above "≈" includes not only the case where both are completely the same, but also the case where both are substantially the same. “Substantially the same” means, for example, “ny ≈ nz” when (ny−nz) × d (where d is the thickness of the film) is -10 to 10 nm, preferably -5 to 5 nm. In the case where (nx-nz) × d is −10 to 10 nm, preferably −5 to 5 nm, it is also included in “nx≈nz”.
There are two types of C plates, a positive C plate (positive C plate) and a negative C plate (negative C plate). The positive C plate satisfies the relationship of the formula (C1), and the negative C plate is It satisfies the relation of the formula (C2). The positive C plate shows a negative value of Rth, and the negative C plate shows a positive value of Rth.
Equation (C1) nz> nx≈ny
Equation (C2) nz <nx≈ny
The above "≈" includes not only the case where both are completely the same, but also the case where both are substantially the same. “Substantially the same” means, for example, that (nx−ny) × d (where d is the thickness of the film) is included in “nx≈ny” even when it is 0 to 10 nm, preferably 0 to 5 nm. Is done.

Further, the wavelength dispersibility of optical anisotropy can be appropriately adjusted by adjusting the type and amount of the polymerizable liquid crystal compound and other components used in the polymerizable liquid crystal composition.

Further, the optically anisotropic layer preferably exhibits reverse wavelength dispersibility. For example, the optically anisotropic layer preferably satisfies the relationship of the following formula (II).
Δn (450) / Δn (550) <1.00 ... (II)
Here, in the formula (II), Δn (450) represents the difference between the maximum refractive index of the optically anisotropic layer at a wavelength of 450 nm and the refractive index in the direction orthogonal to the maximum refractive index, and Δn (550) is the optically anisotropic layer. Represents the difference in refractive index between the maximum refractive index direction and the orthogonal direction thereof at a wavelength of 550 nm.

[Laminated body]
As described above, the uncured layer may be placed on a support or the like. That is, the optically anisotropic layer produced by the production method of the present invention may form a laminate together with a layer other than the optically anisotropic layer.

<Support>
The support is not particularly limited, and among them, a long polymer film is preferable in that continuous production is possible.
Examples of the polymer film include polypropylene and polyolefin / cyclic olefin resins such as norbornene polymers; polyvinyl alcohol; polyester resins such as polyethylene terephthalate and polybutylene terephthalate, and polyethylene naphthalate; polymethacrylic acid esters such as polymethylmethacrylate. -Polyacrylic acid ester; cellulose ester such as triacetyl cellulose, diacetyl cellulose, and cellulose acetate propionate; polyethylene naphthalate; polycarbonate; and a polymer film obtained by filming a copolymer of these. These polymer films can be appropriately selected from the viewpoints of tensile elastic modulus, flexural modulus, parallel light transmittance, haze, optical anisotropy, optical isotropic property, easy peeling property, easy adhesive property and the like.

In the present invention, from the viewpoint of obtaining an optically anisotropic layer having a uniform orientation, the coated surface of the support is smooth when the polymerizable liquid crystal composition is directly applied to the support to form the optically anisotropic layer. The surface roughness Ra is preferably 3 to 50 nm.

Further, when using a long polymer film, in the state of a wound body in which the manufactured laminated body is wound, the polymerizable property in the support is from the viewpoint of preventing shape transfer between the surfaces of the laminated body and a blocking phenomenon. An anti-blocking treatment, a matte treatment, or the like may be performed on the surface opposite to the surface on which the liquid crystal composition is applied. Further, knurling may be provided at the end of the laminated body.

It is also preferable that the support can be peeled off. At this time, when the optically anisotropic layer is directly provided on the support, it is preferable that the optically anisotropic layer can be peeled off at the interface between the support and the optically anisotropic layer. Further, when an orientation layer and / or another layer (intermediate layer) described later is provided between the support and the optically anisotropic layer, any arbitrary layer between the support and the optically anisotropic layer is provided. It is preferable that it can be peeled off at the interface or in the layer.

<Alignment film>
From the viewpoint that it is easy to obtain an optically anisotropic layer having better orientation, it is preferable to provide an alignment film on the support and further provide the above-mentioned optically anisotropic layer on the alignment film.

Various known alignment films can be used as the alignment film. For example, a rubbing film (rubbing alignment film) made of an organic compound such as a polymer, an oblique vapor deposition film of an inorganic compound, a film having microgrooves, and an organic compound. Examples thereof include a membrane obtained by accumulating LB membranes (Langmuir-Blogette membranes) formed by the Langmuir-Bloget method using (for example, ω-tricosanoic acid, dioctadecylmethylammonium chloride, methyl stearyllate, etc.). ..
A photo-alignment film is also preferable as the alignment film from the viewpoint of preventing orientation defects caused by foreign substances.

Examples of the rubbing alignment film include a coating film of polyimide, polyvinyl alcohol, a polymer having a polymerizable group described in JP-A-9-152509, and JP-A-2005-97377 and JP-A-2005-99228. Examples thereof include the alignment film described in Japanese Patent Application Laid-Open No. 2005-128503.

The composition for forming a photoalignment film used for the photoalignment film that can be used in the present invention has been described in many documents and the like. For example, a material using an azo compound described in WO08 / 056597, JP2008-76839, and JP2009-109831; JP2012-155308, JP2014-26261. , JP-A-2014-123091, and JP-A-2015-26050, a photo-oriented polyorganosiloxane composite material; JP-A-2012-234146, a cinnamic acid group-containing cellulose ester material; JP-A-2012- Materials utilizing the optical Fries rearrangement reaction or a reaction similar thereto described in JP-A-145660 and JP-A-2013-238717; JP-A-2016-71286, JP-A-2013-518296, JP-A-2014-533376. No., JP-A-2016-535158, WO10 / 150748, WO11 / 126022, WO13 / 054784, WO14 / 104320, and WO16 / 002722. (For example, a synnamate compound, a chalcone compound, and / or a material in which a coumarin compound is pendant on various polymers) and the like can be used in the composition for forming a photoalignment film.
Among them, a photoalignment film using a photoisomerization reaction of an azo group or a photoalignment film using a photoreaction of a synnamate compound is preferable from the viewpoint of irradiation energy required for photoalignment, orientation regulating power, and the like.

The composition for forming an alignment film may contain a cross-linking agent, a binder, a plasticizer, a sensitizer, a cross-linking catalyst, an adhesion adjusting agent, a leveling agent, and the like, if necessary.

The thickness of the alignment film is not particularly limited and can be appropriately selected depending on the intended purpose. For example, 10 to 1000 nm is preferable, and 10 to 300 nm is more preferable. The surface roughness of the alignment film is as described above.

<Other layers (intermediate layer)>
The laminate may further contain other layers, if desired. For example, a smoothing layer, an easy-adhesion layer, an easy-release layer, a light-shielding layer, a colored layer, a fluorescent layer, an oxygen barrier layer, a water vapor barrier layer, and the like can be mentioned. Layers having one or more such layer functions are collectively referred to as intermediate layers. The intermediate layer may be a layer having a function other than the above-mentioned functions.
An intermediate layer can be provided, for example, between the support and the optically anisotropic layer and / or between the support and the above-mentioned alignment film to exhibit various functions.

〔Polarizer〕
The optically anisotropic layer produced by the production method of the present invention is also preferably used by being incorporated into a polarizing plate. In other words, it is also preferable that the laminate is a polarizing plate.
The polarizing plate has at least an optically anisotropic layer and a polarizer produced by the production method of the present invention. The polarizing plate may be a circular polarizing plate.

<Polarizer>
The polarizer is not particularly limited as long as it is a member having a function of converting light into specific linearly polarized light, and conventionally known absorption-type polarizers and reflection-type polarizers can be used.
As the absorption type polarizer, an iodine-based polarizer, a dye-based polarizer using a dichroic dye, a polyene-based polarizer, and the like are used. Iodine-based polarized light and dye-based polarized light include coated and stretched polarized light, and both can be applied. However, polarized light produced by adsorbing iodine or a dichroic dye on polyvinyl alcohol and stretching it. Children are preferred.
Further, as a method for obtaining a polarizer by stretching and dyeing a laminated film having a polyvinyl alcohol layer formed on a substrate, Japanese Patent No. 5048120, Japanese Patent No. 5143918, Japanese Patent No. 5048120, Japanese Patent No. Examples thereof include Japanese Patent No. 46910205, Japanese Patent No. 4751481, Japanese Patent No. 4751486, and the like, and known techniques relating to these polarizers can also be preferably used.
As the reflective polarizer, a polarizer in which thin films having different birefringences are laminated, a wire grid type polarizer, a polarizer in which a cholesteric liquid crystal having a selective reflection region and a 1/4 wave plate are combined, and the like are used.

The thickness of the polarizer is not particularly limited, but is preferably 3 to 60 μm, more preferably 5 to 30 μm, and even more preferably 5 to 15 μm.

<Optical anisotropic layer of polarizing plate>
The polarizing plate preferably has two or more kinds of optically anisotropic layers.
In this case, at least one of the above two or more kinds of optically anisotropic layers possessed by the polarizer may be an optically anisotropic layer manufactured by the manufacturing method of the present invention, and the other optically anisotropic layers may be used. The sex layer may be an optically anisotropic layer (also referred to as “other optically anisotropic layer”) produced by a method other than the production method of the present invention.
For example, it is preferable that the polarizing plate has a positive A plate and a positive C plate. In this case, the positive A plate is preferably an optically anisotropic layer produced by the production method of the present invention, and the positive C plate is an optically anisotropic layer or other optical produced by the production method of the present invention. An anisotropic layer is preferable.
The polarizing plate having the positive A plate and the positive C plate may have another optically anisotropic layer.

In producing the polarizing plate, the optically anisotropic layer may be arranged directly on the polarizing element by applying a polymerizable liquid crystal composition on the polarizer or the like.
Further, for example, the polarizer and the optically anisotropic layer may be bonded via one or more other layers (adhesive layer or other optically anisotropic layer, etc.).

[Image display device]
The optically anisotropic layer produced by the production method of the present invention may be used in an image display device. The optically anisotropic layer may be used in a form incorporated in the above-mentioned polarizing plate.
The display element used in the image display device is not particularly limited, and examples thereof include a liquid crystal cell, an organic electroluminescence (hereinafter abbreviated as “EL”) panel, and a plasma display panel.
Of these, a liquid crystal cell or an organic EL display panel is preferable. That is, as the image display device, a liquid crystal display device using a liquid crystal cell as a display element or an organic EL display device using an organic EL panel as a display element is preferable.

<Liquid crystal display device>
As the liquid crystal display device which is an example of the image display device, for example, a liquid crystal display device having the above-mentioned polarizing plate and a liquid crystal cell is preferable.
Examples of the liquid crystal cell include a VA (Virtual Optical) mode, an OCB (Optical Compensated Bend) mode, an IPS (In-Place-Switching) mode, and a TN (Twisted Nematic) mode. Further, other methods may be used. An optically anisotropic layer produced by the production method of the present invention is applied and combined with an optical compensation configuration and / or a brightness improvement configuration suitable for a liquid crystal cell to provide excellent wide viewing angle characteristics and prevent light leakage in black display. , And high-brightness display can be realized.
In the image display device, among the polarizing plates provided on both sides of the liquid crystal cell, it is preferable to use the polarizing plate on the front side, and the polarizing plate on the front side and the rear side is used. Is more preferable.

<Organic EL display device>
The organic EL display device as an example of the image display device is preferably an organic EL display device including an organic EL display panel and a circularly polarizing plate arranged on the organic EL display panel. The circularly polarizing plate used here is a form of the above-mentioned polarizing plate.
By having the circularly polarizing plate, it is possible to suppress the phenomenon that external light is reflected by the electrodes of the organic EL panel and lower the display contrast, and it is possible to display high image quality.
As an organic EL panel, a known configuration can be widely used. Further, a touch panel may be further provided.

The present invention will be described in more detail below based on examples. The materials, amounts used, ratios, treatment contents, treatment procedures, etc. shown in the following examples can be appropriately changed as long as they do not deviate from the gist of the present invention. Therefore, the scope of the present invention is not construed as limiting by the examples shown below.

[Example 1]
<Formation of photoalignment film>

(Preparation of Cellulose Achillate Film 1)
-Preparation of Core Layer Cellulose Acetate Dope The following composition was put into a mixing tank and stirred to dissolve each component to prepare a cellulose acetate solution to be used as the core layer cellulose acylate dope.
−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−–
Core layer Cellulose acylate dope -------------
100 parts by mass of cellulose acetate having an acetyl substitution degree of 2.88 ・ 12 parts by mass of the polyester compound B described in Examples of JP-A-2015-227955 ・ 2 parts by mass of the following compound G ・ Methylene chloride (first solvent) 430 parts by mass, methanol (second solvent) 64 parts by mass -------------

Compound G

-Preparation of outer layer cellulose acylate dope 10 parts by mass of the following matting agent solution was added to 90 parts by mass of the above core layer cellulose acylate dope to prepare a cellulose acetate solution to be used as the outer layer cellulose acylate dope.
−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−–
Matte solution −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−–
Silica particles with an average particle size of 20 nm (AEROSIL R972, manufactured by Nippon Aerosil Co., Ltd.) 2 parts by mass Methylene chloride (first solvent) 76 parts by mass Methanol (second solvent) 11 parts by mass The above core layer cellulose acylate dope 1 part by mass Part −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−

The core layer cellulose acylate dope and the outer layer cellulose acylate dope are filtered through a filter paper having an average pore size of 34 μm and a sintered metal filter having an average pore size of 10 μm, and then the core layer cellulose acylate dope and the outer layer cellulose acylate dope on both sides thereof. And three layers were simultaneously cast on a drum at 20 ° C. from the casting port (band casting machine). The film was peeled off with a solvent content of about 20% by mass, both ends of the film in the width direction were fixed with tenter clips, and the film was dried while being stretched in the lateral direction at a stretching ratio of 1.1 times. Then, the obtained film was further dried by transporting it between the rolls of the heat treatment apparatus to prepare an optical film having a thickness of 40 μm, which was used as a cellulose acylate film 1. The core layer of the cellulose acylate film 1 had a thickness of 36 μm, and the outer layers arranged on both sides of the core layer had a thickness of 2 μm, respectively. The in-plane retardation of the obtained cellulose acylate film 1 at a wavelength of 550 nm was 0 nm.
The obtained cellulose acylate film 1 was used as a temporary support for formation.

(Preparation of photo-alignment film)
The following coating liquid for forming a photoalignment film was applied to the surface of the cellulose acylate film 1 which is a temporary support for forming with a # 2 wire bar, and dried with warm air at 60 ° C. for 60 seconds to prepare a coating film. ..
Using an ultra-high pressure mercury lamp (UL750, manufactured by HOYA CANDEO OPTRONICS Co., Ltd.) of 750 mW / cm ^{2, the prepared coating film was vertically irradiated with ultraviolet rays under air. The illuminance of ultraviolet rays was 5 mW / cm 2} in the UV-A region (integration of wavelengths of 320 to 380 nm), and the irradiation amount was 50 mJ / cm ² in the UV-A region.

−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−–
Coating liquid for forming a photo-alignment film −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−
Materials for photo-alignment below 1 part by mass Water 16 parts by mass Butoxyethanol 42 parts by mass Propylene glycol monomethyl ether 42 parts by mass ------------- −−−−−−−

Material for photo-alignment:

<Preparation of optically anisotropic layer A-1>
The following polymerizable liquid crystal composition A was applied to the surface of the slide glass, and the uncured layer formed from the polymerizable liquid crystal composition A was observed with a polarizing microscope while heating. As a result, the isotropic (isotropy) -nematic phase transition temperature (hereinafter, also referred to as “TNI”) at the time of lowering the temperature of the uncured layer is 128 ° C., and the phase transition temperature of the nematic phase-smetic phase (hereinafter, also referred to as “TNI”). (Also referred to as “TSmN”) was 73 ° C. Further, by keeping the temperature below 50 ° C., crystals were gradually generated. The TSmN was 74 ° C. at the time of temperature rise.
According to X-ray diffraction (XRD) measurement, this smectic phase was a smectic A phase in which the layer structure and the liquid crystal compound were orthogonal to each other and there was no order in the layer.

−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−–
Polymerizable liquid crystal composition A
−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−–
The following liquid crystal compound L-1 57.5 parts by mass The following liquid crystal compound L-2 30 parts by mass The following liquid crystal compound L-3 12.5 parts by mass Photopolymerization initiator 1 (the following compound PI-1) 0.5 parts by mass The following is included Fluorine compound F-1 0.2 parts by mass Cyclopentanone 227.1 parts by mass ------------- −

Compound PI-1

The polymerizable liquid crystal composition A was applied onto the photoalignment film using a spin coater to form an uncured layer (layer forming step). The rotation speed was adjusted to a desired thickness between 1000 and 5000 rpm.
Next, the uncured layer was heated to 80 ° C. (first heating temperature) using a hot plate to form a nematic phase, which was maintained at that temperature for 10 seconds (first heating holding time) (nematic phase formation). Process).
Then, using a hot plate, the uncured layer was cooled from the first heating temperature to 65 ° C. (cooling temperature) at a temperature lowering rate of 40 ° C./min to form a smectic phase (cooling step).
Then, the cooling holding time was set to 10 seconds and held at that temperature.
^{Next, for the uncured layer at 65 ° C. (cooling temperature), 30 mJ / cm 2} (integrated exposure at a wavelength of 300 to 390 nm) using an air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) under a nitrogen atmosphere. Was irradiated with ultraviolet rays (first exposure treatment) to form a semi-cured layer (first polymerization step).
Next, the semi-cured layer is heated to 120 ° C. (second heating temperature) at an average heating rate of 100 ° C./min using a hot plate while maintaining the nitrogen atmosphere, and the second heating temperature is further increased. While maintaining this, an air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) is used ^{to irradiate ultraviolet rays of 500 mJ / cm 2} (integrated exposure at a wavelength of 300 to 390 nm) (second exposure treatment) to determine the orientation of the liquid crystal phase. Was fixed (second polymerization step). As a result, a film A-1 (film 1) containing a temporary support for formation, a photoalignment film, and an optically anisotropic layer A-1 was obtained.
The thickness of the formed optically anisotropic layer A-1 was 2.3 μm. Further, when the optical anisotropy of the formed optically anisotropy layer A-1 was measured using AxoScan OPMF-1 (manufactured by Optoscience), Re (550) was 144 nm, Rth (550) was 72 nm, and Re. (450) / Re (550) was 0.87.

[Examples 2 to 19 and Comparative Examples 1 to 5 (Preparation of optically anisotropic layers A-2 to A-24)]
Films A-2 to A-24 (films) containing optically anisotropic layers A-2 to A-24, respectively, according to the production procedure of film 1, except that the conditions of each procedure were changed as shown in Table 1 shown in the latter part. 2 to 24) were prepared.
In Comparative Example 1, the production of the optically anisotropic layer was completed by the first exposure treatment.
In Comparative Example 2, after the nematic phase forming step, exposure was immediately performed without going through the cooling step to complete the preparation of the optically anisotropic layer.
The thickness of the obtained optically anisotropic layer, Re (550), Rth (550), and Re (450) / Re (550) are shown in Table 1.

[Comparative Example 6 (Preparation of Optically Anisotropy Layer A-25)]
<Preparation of optically anisotropic layer>
The following polymerizable liquid crystal composition B was prepared. Compound L-4 was synthesized by the method of JP2011-207765A.
Next, the polymerizable liquid crystal composition B was applied to the surface of the slide glass, and the uncured layer formed from the polymerizable liquid crystal composition B was observed with a polarizing microscope while heating. As a result, when the temperature of the uncured layer was raised, a highly viscous intermediate phase was exhibited from 105 ° C to 137 ° C. Although it was difficult to distinguish the liquid crystal phase, a clear nematic liquid crystal phase was exhibited at 137 ° C. or higher. The nematic liquid crystal phase was up to 180 ° C. or higher, and when the temperature was lowered, the nematic liquid crystal phase exhibited and crystallized up to 61 ° C.

−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−–
Polymerizable liquid crystal composition B
−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−–
The following liquid crystal compound L-4 29.1 parts by mass Photopolymerization initiator 1 (Irgacure 819, manufactured by BASF) 0.87 parts by mass The above-mentioned fluorine-containing compound F-1 0.02 parts by mass Cyclopentanone 70 parts by mass --- −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−–

(Liquid crystal compound L-4)

The polymerizable liquid crystal composition B was applied onto the photoalignment film using a spin coater to form an uncured layer (layer formation step).
Using the obtained uncured layer, the film A-25 (containing the optically anisotropic layer A-25) was prepared according to the production procedure of the film 1, except that the conditions of each procedure were changed as shown in Table 1 shown in the latter part. Film 25) was produced.
The thickness of the obtained optically anisotropic layer, Re (550), Rth (550), and Re (450) / Re (550) are shown in Table 1.

[Preparation of positive C plate]
A transfer film C1 having a positive C plate C-1 provided on a temporary support for formation, a temporary support for formation, in the same manner as the positive C plate described in paragraph [0124] of JP-A-2015-200861. A transfer film C2 having a positive C plate C-2 provided above was produced. When the phase difference was measured using AxoScan OPMF-1 (manufactured by Optoscience), the positive C plate C-1 had Re (550) = 0 nm and Rth (550) = -112 nm, and the positive C plate C-2. Was Re (550) = 0 nm and Rth (550) = −69 nm. The phase difference values of the positive C plate C-1 and the positive C plate C-2 were adjusted by adjusting the thickness.

[Preparation of polarizing plate]
The surface of the support TD80UL (manufactured by FUJIFILM Corporation) was subjected to alkali saponification treatment. Specifically, the support is immersed in a 1.5-standard sodium hydroxide aqueous solution at 55 ° C. for 2 minutes, the removed support is washed in a water-washing bathtub at room temperature, and 0.1-standard sulfuric acid is washed at 30 ° C. Neutralized with. Then, the obtained support was washed again in a water washing bath at room temperature, and further dried with warm air at 100 ° C.
Subsequently, a roll-shaped polyvinyl alcohol film having a thickness of 80 μm was continuously stretched 5 times in an aqueous iodine solution, and the stretched film was dried to obtain a polarizer having a thickness of 20 μm.
The obtained polarizing element was bonded to a support (TD80UL) subjected to an alkali saponification treatment to obtain a polarizing plate 0 in which the polarizing element was exposed on one side.
Next, the polarizing plate 0 and the film 1 were bonded together using an adhesive so that the polarizing element of the polarizing plate 0 and the optically anisotropic layer A-1 faced each other. At this time, the absorption axis of the polarizer and the slow axis of the optically anisotropic layer A-1 are orthogonal to each other.
Subsequently, the temporary support for formation and the photoalignment film were peeled off from the bonded film 1, and only the optically anisotropic layer A-1 was transferred onto the polarizing plate.
Further, the transfer film 1 was bonded onto the optically anisotropic layer via an adhesive so that the optically anisotropic layer A-1 and the positive C plate C-1 face each other. Subsequently, the temporary support for formation is peeled off from the bonded transfer film 1, and the support / polarizer / adhesive / optically anisotropic layer / adhesive / positive C plate C-1 are laminated in this order. The obtained polarizing plate P-1 was obtained.
Instead of the film 1, films 2 to 25 containing optically anisotropic layers A-2 to A-25 were used to obtain polarizing plates P-2 to P-25 according to the same procedure as described above.

[Manufacturing of liquid crystal display device]
The polarizing plate on the visual side was peeled off from the liquid crystal cell of iPad (registered trademark, manufactured by Apple Inc.) and used as a liquid crystal cell in IPS mode.
Instead of the peeled polarizing plate, the polarizing plates P-1 to P-25 prepared above were bonded to a liquid crystal cell to prepare a liquid crystal display device.
At this time, when observed from a direction perpendicular to the liquid crystal cell substrate surface, the absorption axis of the polarizer in each of the polarizing plates P-1 to P-25 and the optical axis of the liquid crystal layer in the liquid crystal cell are perpendicular to each other. They were pasted together so that they were oriented in the same direction.

[Evaluation]
For the measurement of the display performance, a commercially available liquid crystal viewing angle and chromaticity characteristic measuring device Ezcontlast (manufactured by ELDIM) was used, and the liquid crystal display device produced above was used. In the produced liquid crystal display device, the liquid crystal cell to which the polarizing plate produced above was attached was installed so that the optically anisotropic layer was on the opposite side to the backlight side, and the measurement was performed. The results are shown in Table 1 below.

<Panel contrast>
The average value (brightness max) of the maximum ^{black brightness (Cd / m 2} ) in the upward direction (azimuth 0 to 175 ° in 5 ° increments) and downward (azimuth 180 to 355 ° in 5 ° increments). ) Was asked. The smaller the numerical value of the brightness max, the less the light leakage of the black display and the better the panel contrast, and the evaluation was made in the following two stages, A and B.
A: 0.70 or less B: More than 0.70

<Film contrast>
On the table, in order from the bottom, the direct type fluorescent tube backlight source, the upper polarizing plate, the sample (any of the films A-1 to A-25 produced above), and the lower polarizing plate are placed horizontally on each surface. I installed it like this. At this time, the sample and the upper polarizing plate were made rotatable. The brightness of the light emitted from the light source and transmitted through the upper polarizing plate, the sample, and the lower polarizing plate in this order was measured from the vertical direction using a luminance meter (for example, BM-5A (manufactured by TOPCON)). As the upper polarizing plate and the lower polarizing plate, those having a degree of polarization of 99.995% or more were used.

In the measurement, the upper polarizing plate was first rotated in the absence of a sample to adjust to the position where the brightness became the darkest (cross Nicol state).
The sample was inserted and the sample was rotated under cross Nicol to measure the minimum brightness. Next, two polarizing plates, an upper polarizing plate and a lower polarizing plate, were arranged in a parallel Nicol arrangement, and the sample was rotated to measure the maximum brightness.
In order to eliminate the contribution of luminance leakage caused by the upper polarizing plate and the lower polarizing plate, the value obtained by the following formula is defined as the film contrast. The results are shown in Table 1 below.
Contrast = 1 / [{(minimum brightness under cross Nicol when sample is placed) / (maximum brightness under parallel Nicol when sample is placed)}-{(minimum brightness under cross Nicol without sample) / ( Maximum brightness under parallel Nicol without sample)}]
Based on the calculated contrast value, the film contrast was evaluated against the following criteria. The larger the contrast value, the better the film contrast.
A: Contrast is 100,000 or more B: Contrast is 70,000 or more and less than 100,000 C: Contrast is 40,000 or more and less than 70,000 D: Contrast is less than 40,000

<Durability of optically anisotropic layer>
The film 1 was bonded onto a glass plate using an adhesive. Next, the temporary support for formation and the photoalignment film were peeled off from the bonded film 1 to obtain a laminated body in which a glass plate / adhesive / optically anisotropic layer was laminated in this order. The optical anisotropy of this laminate was quantified using AxoScan OPMF-1 (manufactured by Optoscience) (Re (550) a). Further, after allowing the same laminate to elapse for 500 hours under a drying condition of 80 ° C., the optical anisotropy was quantified in the same manner as before the elapse (Re (550) b). The phase difference change rate calculated by the following formula was evaluated according to the following evaluation criteria A to C. The results are shown in Table 1.
(Phase difference rate of change) = | Re (550) a-Re (550) b | ÷ Re (550) a
A: Phase difference change rate is 0.02 or less B: Phase difference change rate is larger than 0.02 and less than 0.04 C: Phase difference change rate is 0.04 or more

The results are shown in Table 1.
In Table 1, the column of "rising temperature range" shows the difference in temperature of the semi-cured layer before and after the second heat treatment.
The column of "TSmN temperature difference at the time of temperature rise" indicates the temperature difference between the first heating temperature and the TSmN at the time of raising the temperature of the uncured layer.
The column of "TSmN temperature difference at the time of temperature decrease" indicates the temperature difference between the cooling temperature and the TSmN at the time of temperature decrease of the uncured layer.

From the results shown in Table 1, it was confirmed that according to the production method of the present invention, an optically anisotropic layer having excellent durability and film contrast and capable of producing an image display device having excellent panel contrast can be obtained. It was.
Above all, when the exposure amount in the first exposure treatment was 10 mJ / cm ² or more, it was confirmed that the film contrast of the optically anisotropic layer was more excellent (comparison between Examples 9 and 10).
It was confirmed that the durability of the optically anisotropic layer was more excellent when the exposure amount in the first exposure treatment was 30 mJ / cm ^{2 or less (comparison of Examples 1, 11 and 12).}
It was confirmed that the film contrast of the optically anisotropic layer was more excellent when the temperature lowering rate in the cooling step was 80 ° C./min or less (more preferably 60 ° C./min or less) (comparison of Examples 17 to 19). ).
It was confirmed that the durability of the optically anisotropic layer is more excellent when the difference between the temperature of the uncured layer during the first exposure treatment and the temperature of the semi-cured layer during the second exposure treatment is 40 ° C. or more. (Comparison with Examples 1 and 3).
It was confirmed that when the exposure amount in the second exposure process was 200 mJ / cm ² or more, the durability of the optically anisotropic layer was more excellent (comparison with Examples 6 and 7).

[Examples 101 and 102]
[Preparation of circularly polarizing plate with positive C plate]
The optics of the polarizing plate of the polarizing plate 0 and the film 1 produced above so that the absorption axis of the polarizing element of the polarizing plate 0 produced above and the slow axis of the optically anisotropic layer intersect at 45 °. The surface of the anisotropic layer was bonded to the surface using an adhesive. Subsequently, the temporary support for formation and the photoalignment film were peeled off from the bonded film 1, and only the optically anisotropic layer was transferred onto the polarizing plate 0.
Further, the surface of the positive C plate C-2 is bonded onto the surface of the above-mentioned optically anisotropic layer using an adhesive, and then the temporary support for formation is peeled off from the polarizing plate to support / polarized light. A circularly polarizing plate CP-1 in which a child / adhesive / optically anisotropic layer / adhesive / positive C plate C-2 was laminated in this order was obtained.

[Manufacturing of organic EL display device]
GALAXY S IV (organic EL display device) manufactured by SAMSUNG, which is equipped with an organic EL display panel, is disassembled, the circular polarizing plate is peeled off, and the circular polarizing plate CP-1 is bonded onto the organic EL display panel, respectively, and the organic EL is displayed. A display device was manufactured.

[Evaluation]
<Reflective color>
Using the organic EL display device before disassembly and the organic EL display device replaced with each circular polarizing plate, the panel reflection color at the time of black display under natural light can be visually observed from the front and the polar angle of 45 °. The evaluation was made according to the following criteria.
A: Compared to the organic EL panel before decomposition, the reflected color is the same or closer to neutral black. B: Coloring is seen compared to the organic EL panel before decomposition.

The results are shown in Table 2.
The column of "specular reflection" in the table shows the evaluation result of the reflected color when visually observed from the front.
The column of "45 ° reflection" shows the evaluation result of the reflected tint when visually observed from the polar angle 45 ° direction.

From the results shown in Table 2, it was confirmed that the optically anisotropic layer obtained by the production method of the present invention can be preferably used for an organic EL display device.

Claims (11)

Step A of forming an uncured layer containing a polymerizable liquid crystal compound,
Step B, in which the uncured layer is heat-treated to form a nematic phase,
Step C of forming a smectic phase by subjecting the uncured layer on which the nematic phase is formed to a cooling treatment,
In step D, the uncured layer on which the smectic phase is formed is subjected to the first exposure treatment to form a semi-cured layer.
Production of an optically anisotropic layer having a step E of subjecting the semi-cured layer to a second exposure treatment to form an optically anisotropic layer under a temperature condition higher than the temperature at the time of the first exposure treatment. Method. The method for producing an optically anisotropic layer according to claim 1, wherein the temperature lowering rate of the uncured layer in the step C is 1 to 100 ° C./min. The method for producing an optically anisotropic layer according to claim 1 or 2, wherein the temperature lowering rate of the uncured layer in the step C is 1 to 60 ° C./min. The method for producing an optically anisotropic layer according to any one of claims 1 to 3, wherein the temperature of the uncured layer gradually decreases in the step C. The method for producing an optically anisotropic layer according to any one of claims 1 to 4, wherein the light used in the first exposure treatment is ultraviolet light. The method for producing an optically anisotropic layer according to any one of claims 1 to 5, wherein the exposure amount in the first exposure process is 1 to 60 mJ / cm ^2. The method for producing an optically anisotropic layer according to any one of claims 1 to 6, wherein the exposure amount in the first exposure process is 10 to 30 mJ / cm ^2. The method for producing an optically anisotropic layer according to any one of claims 1 to 7, wherein the temperature during the second exposure treatment is higher than the phase transition temperature between the smectic phase and the nematic phase of the polymerizable liquid crystal compound. .. The method for producing an optically anisotropic layer according to any one of claims 1 to 8, wherein the difference between the temperature at the time of the first exposure treatment and the temperature at the time of the second exposure treatment is 20 ° C. or more. .. The method for producing an optically anisotropic layer according to any one of claims 1 to 9, wherein the difference between the temperature at the time of the first exposure treatment and the temperature at the time of the second exposure treatment is 40 ° C. or more. .. The method for producing an optically anisotropic layer according to any one of claims 1 to 10, wherein the uncured layer contains an oxime ester-based polymerization initiator.