WO2024024701A1

WO2024024701A1 - Optically anisotropic film and phase difference plate

Info

Publication number: WO2024024701A1
Application number: PCT/JP2023/026899
Authority: WO
Inventors: 奈保実高田; 佑紀齊部; 悟史岡田
Original assignee: Ａｇｃ株式会社
Priority date: 2022-07-27
Filing date: 2023-07-21
Publication date: 2024-02-01

Abstract

The present invention addresses the problem of providing an optically anisotropic film that is a single layer and has sufficient anti-reflection performance throughout the entire wavelength range of 430-680 nm in the visible light range, and a phase difference plate comprising the optically anisotropic film. The present invention relates to an optically anisotropic film that is a single layer and has an ellipticity of 0.9 or more throughout the entire wavelength range of 430-680 nm. The present invention also relates to a phase difference plate or an optical filter comprising the optically anisotropic film.

Description

Optically anisotropic film and retardation plate

The present invention relates to an optically anisotropic film and a retardation plate.

Optically anisotropic films with refractive index anisotropy are used in various applications such as antireflection films for display devices and optical compensation filters for liquid crystal display devices.

Here, Patent Document 1 describes a retardation plate that exhibits reverse wavelength dispersion.

International Publication No. 2018/225474

In a display device, if the antireflection performance is insufficient, color changes when viewed from an oblique direction and light leakage when displaying black are likely to occur. Therefore, sufficient antireflection performance is required in the visible light region, particularly in the entire wavelength region of 430 to 680 nm.

However, the technique described in Patent Document 1 does not provide sufficient antireflection performance in some visible light regions.

Further, the optically anisotropic film may have a single-layer structure or a structure in which a plurality of layers are laminated, but from the viewpoint of reducing the height of the display device, a single-layer structure that can be more easily reduced in height is preferable.

An object of the present invention is to provide a single-layer optically anisotropic film having sufficient antireflection performance over the entire wavelength range of 430 to 680 nm in the visible light region, and a retardation plate equipped with the same.

The present invention relates to the following optically anisotropic film.
A single-layer optically anisotropic film having an ellipticity of 0.9 or more in the entire wavelength range of 430 to 680 nm.

The present invention also relates to a retardation plate comprising the optically anisotropic film described above.

According to the present invention, it is possible to provide a single-layer optically anisotropic film having sufficient antireflection performance over the entire wavelength range of 430 to 680 nm in the visible light region, and a retardation plate equipped with the optically anisotropic film.

FIG. 1 is a graph showing the ellipticity mainly in the wavelength region of visible light in the optically anisotropic film of Example 1-1. FIG. 2 is a graph showing the ellipticity mainly in the wavelength region of visible light in the optically anisotropic film of Example 1-2. FIG. 3 is a graph showing the ellipticity mainly in the wavelength region of visible light in the optically anisotropic film of Example 1-3. FIG. 4 is a graph showing the ellipticity mainly in the wavelength region of visible light in the optically anisotropic film of Example 1-4.

Embodiments of the present invention will be described below.
In this specification, the compound represented by formula (A1) is also referred to as compound (A1), and the same applies to cases where it is represented by other formulas. The dye composed of compound (A1) is also referred to as dye (A1), and the same applies to cases where it is expressed by other formulas. For example, the group represented by formula (1a) is also referred to as group (1a), and the same applies to groups represented by other formulas.
In this specification, "~" representing a numerical range includes the upper and lower limits.

In this specification, unless otherwise specified, the alkyl group may be linear, branched, cyclic, or a combination of these structures.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like, unless otherwise specified, with a fluorine atom being preferred.
In this specification, unless otherwise specified, an aryl group refers to a group bonded via a carbon atom constituting an aromatic ring of an aromatic compound, such as a benzene ring, a naphthalene ring, or a biphenyl ring. Further, the heteroaryl group refers to a group bonded via a carbon atom or a heteroatom constituting an aromatic ring of an aromatic compound having a heteroatom, such as a furan ring, a thiophene ring, or a pyrrole ring.

As used herein, a squarylium compound refers to a compound having a squarylium skeleton represented by the following formula (S1) that can have a resonance structure represented by the following formula (S2) in the structural formula. In this specification, the squarylium skeleton is represented by either formula (S1) or formula (S2).

In this specification, Re represents in-plane retardation.
Retardation is measured using a retardation measuring device (for example, RETS-100 manufactured by Otsuka Electronics).

In this specification, ellipticity can be converted from retardation using the following equations (1) and (2). Let θ be the ellipticity angle, Re be the retardation, and λ be the wavelength.
Ellipticity X=tanθ (1)
sin2θ=sin(Re/λ×360°) (2)
The ellipticity can also be measured using an ellipticity measuring device (for example, RETS-100 manufactured by Otsuka Electronics).

In this specification, spectral characteristics can be measured using a spectrophotometer. Further, if there is no particular description regarding the measurement direction, it means the characteristics at an incident angle of 0°.

<Optically anisotropic film>
The optically anisotropic film according to the embodiment of the present invention has an ellipticity of 0.9 or more in the entire wavelength range of 430 to 680 nm. Here, the ellipticity has a correlation with retardation (phase difference). When an optically anisotropic film is used as a 1/4 wavelength plate, linearly polarized light is converted to completely circularly polarized light when Re=λ/4 (ellipticity=1), and ideal optical characteristics are obtained. In other words, if the ellipticity is above the above range in the entire visible light wavelength range of 430 to 680 nm, the retardation (phase difference) will follow the ideal straight line λ/4 in that region, resulting in poor anti-reflection performance and color fading prevention performance. An excellent optically anisotropic film can be obtained.
The optically anisotropic film according to the embodiment of the present invention preferably has an ellipticity of 0.92 or more in the entire wavelength range of 430 to 680 nm.
In order for the optically anisotropic film according to the embodiment of the present invention to satisfy the above-mentioned ellipticity, for example, the optically anisotropic film may contain a specific near-infrared light absorbing dye described below.

It is preferable that the optically anisotropic film according to the embodiment of the present invention has a transmittance of 97% or more at at least one of a wavelength of 830 nm and a wavelength of 850 nm. It is more preferable that the optically anisotropic film has a transmittance of 97% or more at both wavelengths of 830 nm and 850 nm. Wavelengths around 830 nm and 850 nm are one of the wavelengths used in eye tracking in augmented reality (VR) and virtual reality (AR) and sensing in near-infrared light sensors. When the optically anisotropic film has a transmittance of 97% or more at at least one of wavelengths of 830 nm and 850 nm, eye tracking performance and sensing performance can be improved. The transmittance of the optically anisotropic film at at least one of a wavelength of 830 nm and a wavelength of 850 nm is more preferably 98% or more.
In order for the optically anisotropic film according to the embodiment of the present invention to satisfy the above-mentioned transmittance at at least one of the wavelengths of 830 nm and 850 nm, for example, the optically anisotropic film must contain a specific near-infrared light absorbing dye described below. Including.

The optically anisotropic film according to the embodiment of the present invention preferably has an average transmittance of 95% or more in the wavelength range of 430 to 680 nm. Since the optically anisotropic film has excellent visible light transmittance, it can improve image quality and color reproducibility when used in display devices and the like. The average transmittance of the optically anisotropic film at a wavelength of 430 to 680 nm is more preferably 97% or more.

The optically anisotropic film according to the embodiment of the present invention preferably has a maximum absorption wavelength of less than 780 nm in the wavelength range of 650 to 1100 nm. If the maximum absorption wavelength is less than 780 nm, the transmittance of the optically anisotropic film at at least one of the wavelengths of 830 nm and 850 nm can be maintained high without decreasing. The maximum absorption wavelength in the wavelength range of 650 to 1100 nm is more preferably 770 nm or less.

The optically anisotropic film according to the embodiment of the present invention preferably has a maximum absorption wavelength of 750 nm or more in the wavelength range of 650 to 1100 nm. If the maximum absorption wavelength is 750 nm or more, visible light transmittance can be maintained at a high level without absorbing visible light. The maximum absorption wavelength in the wavelength range of 650 to 1100 nm is more preferably 760 nm or more.

In order to make the maximum absorption wavelength of the optically anisotropic film in the wavelength range of 650 to 1100 nm within the above range, for example, the optically anisotropic film may contain a specific near-infrared light absorbing dye described below.

In the optically anisotropic film according to the embodiment of the present invention, the dichroic ratio of the maximum absorption wavelength in the wavelength range of 650 to 1100 nm is preferably 1.5 or more, more preferably 2.0 or more. If the dichroic ratio of the maximum absorption wavelength is in the range, there is no need to increase the dye content in the optically anisotropic film, and the transmittance of visible light and near-infrared light near the sensing wavelength can be maintained high, which is preferable. .
The optically anisotropic film according to the embodiment of the present invention preferably exhibits reverse wavelength dispersion. Reverse wavelength dispersion refers to the fact that when measuring the in-plane retardation (Re) value of an optically anisotropic film at a specific wavelength (visible light range), the Re value becomes equal or higher as the measurement wavelength becomes larger. .

<Near infrared absorbing dye>
The optically anisotropic film according to the embodiment of the present invention preferably contains a near-infrared absorbing dye, particularly a near-infrared absorbing dye having a specific structure described below. This makes it possible to increase the ellipticity of the optically anisotropic film in the visible light region.
The near-infrared absorbing dye is preferably a dye having dichroism in the near-infrared region.
Having dichroism means that the absorbance in the long axis direction of the dye is different from the absorbance in the short axis direction. Furthermore, it is more preferable that the absorbance in the short axis direction is greater than the absorbance in the long axis direction in the near-infrared region. Thereby, the ellipticity of the optically anisotropic film in the visible light region can be further increased.

Generally, the refractive index of an organic dye decreases monotonically as the wavelength increases in a wavelength region away from the intrinsic absorption wavelength. Such a phenomenon is called normal dispersion. On the other hand, in a wavelength region that includes a unique absorption wavelength, the refractive index changes rapidly as the wavelength increases, which is called anomalous dispersion. Specifically, there is a behavior in which the refractive index rapidly decreases on the short wavelength side of the specific absorption wavelength, and rapidly increases on the long wavelength side of the specific absorption wavelength.
As described above, when an optically anisotropic film is used as a quarter-wave plate, linearly polarized light is converted to completely circularly polarized light when Re=λ/4, and ideal optical characteristics are obtained.
In near-infrared absorbing dyes, the refractive index in the short axis direction decreases rapidly just before the characteristic absorption wavelength, so the refractive index difference increases on the long wavelength side of the visible light region. The in-plane retardation of an optically anisotropic film is calculated from the product of the refractive index difference and the film thickness, so if the film thickness is constant, the retardation increases as the refractive index difference increases. It is possible to approach λ/4 over the entire 680 nm range.

The absorbance in the long axis direction of the near-infrared absorbing dye is measured from the absorption spectrum obtained by irradiating the optically anisotropic film with polarized light parallel to the orientation direction of the near-infrared absorbing dye. is measured from the absorption spectrum obtained by irradiating the optically anisotropic film with polarized light perpendicular to the alignment direction of the near-infrared absorbing dye.

The near-infrared absorbing dye preferably has a dichroic ratio of 1.5 or more, more preferably 2.0 or more. The larger the dichroic ratio, the more easily the retardation increases in the long wavelength region, and the easier it is to approach λ/4 over the entire wavelength range of 430 to 680 nm in visible light, thus obtaining an optically anisotropic film with a high ellipticity in this region. be able to. Further, since the effect of increasing retardation can be obtained even in a small amount, there is no need to increase the content in the optically anisotropic film, and the transmittance of visible light and near-infrared light near the sensing wavelength can be maintained high.

The near-infrared absorbing dye preferably has a maximum absorption wavelength in the wavelength range of 650 to 900 nm in dichloromethane. By having the maximum absorption wavelength in this range, the retardation in the long wavelength region increases and tends to approach λ/4 over the entire wavelength range of 430 to 680 nm in visible light, resulting in optical anisotropy with high ellipticity in this region. A sexual membrane can be obtained. Furthermore, from the viewpoint of improving eye tracking performance and sensing performance, it is more preferable to have a maximum absorption wavelength of 700 to 800 nm.

The near-infrared absorbing dye also preferably satisfies the following spectral characteristics when the transmittance at the maximum absorption wavelength is 10% in a spectral transmittance curve measured after being dissolved in dichloromethane.
The average transmittance at a wavelength of 400 to 500 nm is preferably 95% or more, more preferably 97% or more.
The minimum transmittance at a wavelength of 400 to 500 nm is preferably 85% or more, more preferably 90% or more.
The average transmittance at a wavelength of 500 to 600 nm is preferably 95% or more, more preferably 97% or more.
The minimum transmittance at a wavelength of 500 to 600 nm is preferably 90% or more, more preferably 93% or more.
By satisfying the above spectral characteristics, an optically anisotropic film with excellent visible light transmittance can be obtained, which is preferable.

It is preferable that the near-infrared absorbing dye has a squarylium skeleton. If the dye has a squarylium skeleton, its absorption in the visible light region is small, so that it is possible to suppress coloring of the resulting optically anisotropic film.

It is preferable that the near-infrared absorbing dye has a mesogenic group. A mesogenic group is a functional group that is rigid and has orientation. The mesogenic group preferably has a structure containing two or more cyclic structures such as an aromatic ring or an alicyclic ring, and more preferably a structure in which such cyclic structures are connected directly or via a linking group. Since the near-infrared absorbing dye has a mesogenic group, the dye is easily oriented in the optically anisotropic film, and predetermined optical properties can be easily controlled.

As the near-infrared absorbing dye, a compound represented by the following formula (3) is more preferable.
R _L -D R _L (3)
In formula (3), D is a divalent group having a squarylium skeleton, and R _L is a monovalent mesogenic group. Two R _L may be the same or different.
In the case of the above-mentioned near-infrared absorbing dye (3), the two mesogenic groups bond symmetrically around the squarylium skeleton, making it easier to align with the liquid crystal compound.

The mesogenic group R _L is preferably represented by the following formula (2).
R _L '-Sp1-[Cy-Sp2] _n -Sp3- (2)
In formula (2), R _L ' is a hydrogen atom, a monovalent organic group having electron-withdrawing properties, or a monovalent organic group having polymerizability.
Examples of the monovalent organic group having electron-withdrawing properties include CN, CF ₃ , F, and the like.
Examples of the monovalent organic group having polymerizability include a polymerizable group capable of radical polymerization or cationic polymerization.
As the radically polymerizable group, a known radically polymerizable group can be used, and an acryloyl group or a methacryloyl group is preferable.
As the cationic polymerizable group, a known cationic polymerizable group can be used, and specifically, an alicyclic ether group, a cyclic acetal group, a cyclic lactone group, a cyclic thioether group, a spiro-orthoester group, and a vinyloxy Examples include groups. Among these, an alicyclic ether group or a vinyloxy group is preferred, and an epoxy group, an oxetanyl group, or a vinyloxy group is more preferred.

The structure of R _L ', which is the terminal of the mesogenic group, can be selected depending on the purpose of the optically anisotropic film to be obtained. For example, in the case of a voltage-driven liquid crystal, a monovalent organic group with electron-withdrawing properties is preferable, and in the case of a liquid crystal with a polymerizable group, a monovalent organic group with polymerizability is preferable, and the hydrogen atom does not depend on the purpose. preferable.

In formula (2), Cy is an arylene group that may have a substituent, a heteroarylene group that may have a substituent, or a cycloalkylene group that may have a substituent.
Examples of the arylene group include a phenylene group, a naphthalene group, and a tetrahydronaphthalene group.
Examples of the heteroarylene group include a furan ring, a pyrrole ring, a thiophene ring, a pyridine ring, a thiazole ring, and a benzothiazole ring.
Examples of the cycloalkylene group include a cyclohexylene group, a cyclohexelene group, a decahydronaphthalene group, and a dioxane group.
Examples of the substituent for Cy include a methyl group and a methoxy group.

In formula (2), Sp1, Sp2, and Sp3 each independently represent one type of group or bond selected from a single bond, an alkylene group, an alkenylene group, an alkynylene group, a carbonyl group, an ester bond, an amide bond, and an ether bond. , or a combination of these.
The alkylene group is preferably a straight chain alkylene group having 1 to 12 carbon atoms.

n is an integer from 2 to 9, preferably from 2 to 6.
Furthermore, in formula (2), two or more [Cy-Sp2] structures may be the same or different.

The mesogenic group represented by formula (2) preferably includes structures represented by the following formulas, with structures represented by formulas (2-2) and (2-4) being particularly preferred.

As the near-infrared absorbing dye, at least one selected from a compound represented by the following formula (3-1A), a compound represented by the following formula (3-1B), and a compound represented by the following formula (3-2) is used. One type is more preferable.
Compounds (3-1A) to (3-2) below have mesogenic groups extending in a direction perpendicular to the squarylium skeleton at the center of the compound, so that the optically anisotropic film formed is slow. The squarylium skeleton is likely to be arranged in a direction perpendicular to the phase axis. In other words, absorption in the infrared region (particularly wavelengths of 700 to 900 nm) originating from the squarylium skeleton is likely to be obtained in the direction perpendicular to the slow axis of the optically anisotropic film, and an optically anisotropic film exhibiting desired characteristics can be obtained. Easy to obtain.

In formula (3-1A), formula (3-1B), and formula (3-2), R _L is the same as the definition of R _L in formula (2) above, and preferred embodiments are also the same.

In formula (3-1A), X ¹ is a carbon atom or nitrogen atom that may have a monovalent substituent. From the viewpoint of improving red transmittance, carbon atoms are preferable, and from the viewpoint of improving blue transmittance, nitrogen atoms are preferable. Monovalent substituents on carbon atoms include hydrogen atoms, halogen atoms, alkyl groups having 1 to 9 carbon atoms, alkenyl groups, alkynyl groups, aromatic rings that may have substituents, hydroxyl groups, carboxy groups, and sulfo groups. , a cyano group, an amino group, an N-substituted amino group, a nitro group, an alkoxycarbonyl group, a carbamoyl group, an N-substituted carbamoyl group, an imide group, and an alkoxy group having 1 to 19 carbon atoms.

In formula (3-1A), Y ¹ is an oxygen atom, a sulfur atom, or an NH group. When Y ¹ is one of these elements or groups, the five-membered ring containing Y ¹ becomes aromatic, and the blue light transmittance is improved. From the viewpoint of improving red light transmittance, a sulfur atom is preferable, and from the viewpoint of improving red light transmittance and steepening absorption due to hydrogen bonding, an NH group is preferable.

In formula (3-1B), X ² is a sulfur atom or an oxygen atom. Sulfur atoms are preferred from the viewpoint of improving red light transmittance.
In formula (3-1B), Y ² is a carbon atom or nitrogen atom that may have a monovalent substituent. Nitrogen atoms are preferred from the viewpoint of improving blue light transmittance. Monovalent substituents on carbon atoms include hydrogen atoms, halogen atoms, alkyl groups having 1 to 9 carbon atoms, hydroxyl groups, carboxy groups, sulfo groups, cyano groups, amino groups, and N-substituted amino groups. , a nitro group, an alkoxycarbonyl group, a carbamoyl group, an N-substituted carbamoyl group, an imide group, and an alkoxy group having 1 to 19 carbon atoms.

In formula (3-1A) and formula (3-1B), R ¹¹ and R ¹² may each independently have a substituent, and may have an unsaturated bond between carbon atoms, an oxygen atom, or a fatty acid. It is an alkyl group having 1 to 20 carbon atoms and which may contain a ring or an aromatic ring.
The alkyl group may be linear or branched, preferably linear from the viewpoint of orientation, and preferably branched from the viewpoint of solubility.

The alkyl group having 1 to 20 carbon atoms is preferably a linear alkyl group having 1 to 15 carbon atoms, more preferably a linear alkyl group having 1 to 10 carbon atoms. If it is branched, a branched alkyl group having 3 to 15 carbon atoms is preferred, and a branched alkyl group having 3 to 8 carbon atoms is more preferred.

Furthermore, it is more preferable that at least one of R ¹¹ and R ¹² is a branched alkyl group having 3 to 15 carbon atoms, and both R ¹¹ and R ¹² are branched alkyl groups having 3 to 8 carbon atoms. is particularly preferred.
R ¹¹ and R ¹² may be the same or different, but are preferably the same from the viewpoint of symmetry.

In addition, when ^R11 and ^R12 have a substituent, the carbon number of a substituent is included in the carbon number of ^R11 and ^R12 . Substituents include halogen atom, hydroxyl group, carboxy group, sulfo group, cyano group, amino group, N-substituted amino group, nitro group, alkoxycarbonyl group, carbamoyl group, N-substituted carbamoyl group, imide group, and carbon number 1 to 19 alkoxy groups are mentioned.

In formula (3-1A) and formula (3-1B), R ¹³ and R ¹⁴ are each independently a hydrogen atom or an alkyl group having 1 to 12 carbon atoms. Hydrogen atoms are preferred from the viewpoint of orientation.

In formula (3-1A) and formula (3-1B), R ¹¹ and R ¹² , R ¹¹ and R ¹³ , R ¹² and R ¹³ , R ¹³ and R ¹⁴ are bonded to each other to form a ring. Good too. The number of members in the ring is preferably 4 to 6.

More specifically, the compound represented by formula (3-1A) includes the compounds shown in the table below. In the compound (3-1A), the case where X ¹ is a nitrogen atom and Y ¹ is an NH group is defined as a compound (3-1Ai), and the case where X ¹ is a carbon atom and Y ¹ is an NH group is defined as a compound (3-1Ai). It is referred to as compound (3-1Aii). Furthermore, in the compounds shown in the table below, each symbol has the same meaning on the left and right sides of the squarylium skeleton.
Moreover, R _L is as defined above.

More specifically, the compound represented by formula (3-1B) includes the compounds shown in the table below. In compound (3-1B), the case where X ² is a sulfur atom is referred to as compound (3-1Bi), and the case where X ² is an oxygen atom is referred to as compound (3-1Bii). Furthermore, in the compounds shown in the table below, each symbol has the same meaning on the left and right sides of the squarylium skeleton.
Moreover, R _L is as defined above.

In formula (3-2), R ²¹ and R ²² may each independently have a substituent, or may contain an unsaturated bond, an oxygen atom, an alicyclic ring, or an aromatic ring between carbon atoms. It is a good alkyl group having 1 to 20 carbon atoms.
The alkyl group may be linear or branched, preferably linear from the viewpoint of orientation, and preferably branched from the viewpoint of solubility.

Furthermore, it is more preferable that at least one of R ²¹ and R ²² is a branched alkyl group having 3 to 15 carbon atoms, and both R ²¹ and R ²² are branched alkyl groups having 3 to 8 carbon atoms. is particularly preferred.
R ²¹ and R ²² may be the same or different, but are preferably the same from the viewpoint of symmetry.

In addition, when ^R21 and ^R22 have a substituent, the carbon number of the substituent is included in the carbon number of ^R21 and ^R22 . Substituents include halogen atom, hydroxyl group, carboxy group, sulfo group, cyano group, amino group, N-substituted amino group, nitro group, alkoxycarbonyl group, carbamoyl group, N-substituted carbamoyl group, imide group, and carbon number 1 to 19 alkoxy groups are mentioned.

In formula (3-2), R ²³ is a hydrogen atom or an alkyl group having 1 to 12 carbon atoms. Hydrogen atoms are preferred from the viewpoint of orientation.

In formula (3-2), R ²¹ and R ²² , R ²¹ and R ²³ , and R ²² and R ²³ may be bonded to each other to form a ring. The number of members in the ring is preferably 4 to 6.

More specifically, the compound represented by formula (3-2) includes the compounds shown in the table below. Furthermore, in the compounds shown in the table below, each symbol has the same meaning on the left and right sides of the squarylium skeleton.
Moreover, R _L is as defined above.

<Method for producing near-infrared absorbing dye>
Near-infrared absorbing dyes can be produced, for example, by the synthesis method shown below.

The method for synthesizing the near-infrared absorbing dye (3-1Ai) is shown below. Note that the starting materials are commercially available. R _L CHO can be synthesized, for example, according to a known production method described in paragraph [0131] of Japanese Patent Application Publication No. 2011-207782.

The method for synthesizing the near-infrared absorbing dye (3-1Aii) is shown below. Note that the starting materials are commercially available. R _L Br can be synthesized according to the known production method described in, for example, Synlett, 2009, 20, 3279-3282.

The method for synthesizing near-infrared absorbing dyes (3-1Bi) and (3-1Bii) is shown below. Note that the starting materials are commercially available. R _L COCl can be synthesized, for example, according to a known production method described in paragraph [0093] of Japanese Patent Application Publication No. 2014-58490.

The method for synthesizing the near-infrared absorbing dye (3-2) is shown below. Note that the starting material can be synthesized, for example, according to the known production method described in International Publication No. 2021/112020. R _L BPin is, for example, Org. Biomol. Chem. , 2016, 14, 9974-9980 and the like.

The optically anisotropic film according to the embodiment of the present invention may contain only one type of near-infrared absorbing dye, or may contain a combination of multiple types of near-infrared absorbing dye.
The content of the near-infrared absorbing dye in the optically anisotropic film is preferably 0.1 to 15% by mass, more preferably 0.5 to 10% by mass, particularly preferably 1 to 8% by mass, and improves ellipticity. From the viewpoint of visible light transmittance, it is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, particularly preferably 1% by mass or more, and from the viewpoint of visible light transmittance, preferably 15% by mass or less, more preferably is 10% by mass or less, particularly preferably 8% by mass or less.

<Liquid crystal compound>
The optically anisotropic film according to the embodiment of the present invention preferably contains a liquid crystal compound. This makes it easy to orient the near-infrared absorbing dye within the film, resulting in an optically anisotropic film with controlled optical properties.

The liquid crystal compound is preferably a liquid crystal compound that transmits visible light from the viewpoint of visible light transmittance.
Examples of the liquid crystal compound include non-polymerizable liquid crystal compounds that exhibit a nematic phase, polymerizable liquid crystal compounds that exhibit a nematic phase, and polymerizable liquid crystal compounds that exhibit a smectic phase. From the viewpoint of orientation, non-polymerizable liquid crystal compounds exhibiting a nematic phase and polymerizable liquid crystal compounds exhibiting a nematic phase are preferred.

Further, the liquid crystal compound preferably exhibits reverse wavelength dispersion. A liquid crystal compound exhibiting reverse wavelength dispersion (hereinafter also referred to as a reverse wavelength dispersion liquid crystal compound) means a compound in which an optically anisotropic film produced using the compound exhibits reverse wavelength dispersion. In other words, a reverse wavelength dispersion liquid crystal compound is the liquid crystal compound that is used when measuring the in-plane retardation (Re) value at a specific wavelength (visible light range) of an optically anisotropic film made using only this compound. , the Re value remains the same or increases as the measurement wavelength increases.
A liquid crystal compound exhibiting reverse wavelength dispersion is preferable because it improves retardation on the short wavelength side.

The liquid crystal compound may be synthesized by known manufacturing methods described in, for example, International Publication No. 2009/148142, Japanese Patent Application Publication No. 2011-207765, International Publication No. 2021/039625, etc., or commercially available products. May be used.

As the liquid crystal compound exhibiting reverse wavelength dispersion, known compounds can be used, for example, the liquid crystal compounds shown below and those described in Japanese Patent Application Publication No. 2011-207765, International Publication No. 2021/039625, etc. Liquid crystal compounds can be used.

The optically anisotropic film according to the embodiment of the present invention may include a plurality of liquid crystal compounds. When using a plurality of liquid crystal compounds, a plurality of reverse wavelength dispersion liquid crystal compounds may be included, or a flat wavelength dispersion liquid crystal compound may be included in addition to the reverse wavelength dispersion liquid crystal compound. When the liquid crystal compound includes a reverse wavelength dispersion liquid crystal compound and a flat wavelength dispersion liquid crystal compound, the optically anisotropic film preferably exhibits reverse wavelength dispersion. By mixing a flat wavelength dispersive liquid crystal compound, reverse wavelength dispersion can be adjusted.

A flat dispersion liquid crystal compound means a compound in which an optically anisotropic film produced using only the compound as a liquid crystal compound exhibits flat dispersion. In other words, a flat dispersion liquid crystal compound is a liquid crystal compound that, when the in-plane retardation (Re) value at a specific wavelength (visible light range) of an optically anisotropic film prepared using only the compound is measured. The in-plane retardation value hardly changes from the short wavelength side to the long wavelength side.　

The content of the liquid crystal compound in the optically anisotropic film according to the embodiment of the present invention is preferably 50 to 99.9% by mass, more preferably 80 to 99.5% by mass, particularly preferably 90 to 99% by mass. The content is preferably 50% by mass or more, more preferably 80% by mass or more, particularly preferably 90% by mass or more from the viewpoint of developing a stable liquid crystal phase over a wide temperature range, and is also preferred from the viewpoint of achieving sufficient absorbance. is 99.9% by mass or less, more preferably 99.5% by mass or less, particularly preferably 99% by mass or less.

The optically anisotropic film according to the embodiment of the present invention may contain other components in addition to the above-described near-infrared absorbing dye and liquid crystal compound.
The optically anisotropic film may contain a polymer of polymerizable monomers as other components, for example, when the liquid crystal compound is a polymerizable liquid crystal compound.
Examples of the polymerizable monomer include radically polymerizable or cationically polymerizable compounds. Among these, polyfunctional radically polymerizable monomers are preferred. Moreover, as the polymerizable monomer, a monomer copolymerizable with the polymerizable liquid crystal compound is preferable.
The content of the polymerizable monomer in the optically anisotropic film is preferably 1 to 50% by mass, more preferably 2 to 30% by mass, based on the total mass of the liquid crystal compound.

The optically anisotropic film may contain, for example, a surfactant as other components.
Examples of the surfactant include conventionally known compounds.

The optically anisotropic film may contain, for example, an antioxidant as other components. Examples of the antioxidant include Irganox 1010 (manufactured by BASF).

The optically anisotropic film may contain various alignment control agents such as a vertical alignment agent and a horizontal alignment agent as other components. These alignment control agents are compounds that can control the alignment of the liquid crystal compound horizontally or vertically on the interface side.

The optically anisotropic film according to the embodiment of the present invention has a single layer structure. Further, the thickness of the optically anisotropic film is preferably 0.5 to 4.0 μm, more preferably 1.5 to 3.0 μm from the viewpoint of retardation.

<Method for manufacturing optically anisotropic film>
The optically anisotropic film according to the embodiment of the present invention includes, for example, a composition containing the above-mentioned near-infrared absorbing dye, the above-mentioned liquid crystal compound as necessary, other components, and optional components necessary during production. Can be manufactured by curing.

Optional components necessary during production include a solvent and a polymerization initiator when the liquid crystal compound is a polymerizable liquid crystal compound.
The polymerization initiator is selected depending on the type of polymerization reaction, and includes, for example, a thermal polymerization initiator and a photopolymerization initiator. Examples of the photopolymerization initiator include α-carbonyl compounds, acyloin ethers, α-hydrocarbon-substituted aromatic acyloin compounds, polynuclear quinone compounds, and combinations of triarylimidazole dimer and p-aminophenyl ketone. It will be done.
The content of the polymerization initiator in the composition is preferably 0.01 to 20% by mass, more preferably 0.5 to 10% by mass, based on the total solid content of the composition.
As the solvent, organic solvents are preferred. Organic solvents include amides, sulfoxides, heterocyclic compounds, hydrocarbons, alkyl halides, esters, ketones, and ethers. Note that two or more types of organic solvents may be used in combination.

The method for curing the composition is not particularly limited, and any known method can be used. Further, in the optically anisotropic film, the near-infrared absorbing dye is preferably oriented.

When the optically anisotropic film does not contain a liquid crystal compound, the near-infrared absorbing dye can be oriented by, for example, producing a film from a composition containing a near-infrared absorbing dye and stretching the film. The method of stretching the film is to convey it into a heating furnace while holding both ends of the film with clips, and then to stretch the film in either the length direction or the width direction with the clips holding both ends of the film in the heating furnace. uniaxial stretching method in which heat stretching is carried out in one direction, sequential biaxial stretching method in which heat stretching is carried out in either the length or width direction, and then heat stretching in the other direction; A simultaneous biaxial stretching method that performs heating and stretching in two directions simultaneously can be employed.

When the optically anisotropic film contains a liquid crystal compound, the near-infrared absorbing dye can be aligned by aligning the liquid crystal compound. For example, a composition containing a near-infrared absorbing dye, a liquid crystal compound, etc. (hereinafter also referred to as "liquid crystal composition") is applied to form a coating film, and the coating film is subjected to an alignment treatment to align the liquid crystal compound. Further, if the liquid crystal compound is a polymerizable liquid crystal compound, an optically anisotropic film can be formed by subjecting the obtained coating film to a curing treatment (light irradiation treatment or heat treatment).

Hereinafter, the procedure for forming an optically anisotropic film by aligning a polymerizable liquid crystal compound will be described in detail.

First, a liquid crystal composition is applied onto a support to form a coating film, and the coating film is subjected to an alignment treatment to align the polymerizable liquid crystal compound.

The support used is a member that functions as a base material for applying the composition. The support may be a temporary support that is peeled off after the liquid crystal composition is applied and cured.
As the support (temporary support), a plastic film or a glass substrate can be used.
The thickness of the support is preferably 5 to 1000 μm, more preferably 10 to 300 μm, particularly preferably 15 to 90 μm.

Note that an alignment layer may be placed on the support, if necessary.
The alignment layer generally has a polymer as its main component. Polymers for alignment layers are described in many documents, and many commercially available products are available. The polymer for the alignment layer is preferably polyvinyl alcohol, polyimide, or a derivative thereof.
Note that the alignment layer is preferably subjected to known rubbing treatment, photo alignment treatment, or groove alignment treatment.
The thickness of the alignment layer is preferably 0.01 to 10 μm, more preferably 0.01 to 1 μm.

Methods for applying the liquid crystal composition include curtain coating method, dip coating method, spin coating method, print coating method, spray coating method, slot coating method, roll coating method, slide coating method, blade coating method, gravure coating method, and , wire bar method, etc. Regardless of which method is used, single-layer coating is preferred.

The coating film formed on the support is subjected to an alignment treatment to align the polymerizable liquid crystal compound in the coating film.
The orientation treatment can be performed by drying the coating film at room temperature or by heating the coating film. In the case of a thermotropic liquid crystal compound, the liquid crystal phase formed by the alignment treatment can generally be transformed by changing temperature or pressure. In the case of a lyotropic liquid crystal compound, the transition can also be caused by changing the composition ratio such as the amount of solvent.

Note that the conditions for heating the coating film are not particularly limited, but the heating temperature is preferably 50 to 250°C, more preferably 50 to 150°C, and the heating time is preferably 10 seconds to 10 minutes.
Moreover, after the coating film is heated, the coating film may be cooled, if necessary, before the curing treatment (light irradiation treatment) described below. The cooling temperature is preferably 20 to 200°C, more preferably 20 to 150°C.
Note that the difference between the heating temperature of the coating film described above and the cooling temperature of the coating film described above is not particularly limited, and is preferably 40 to 150°C.
In particular, when heating and cooling the coating film before curing treatment, the heating temperature TA of the coating film is 50 to 250°C, and the cooling temperature TB is heating temperature TA × 0.1 to The range is preferably heating temperature TA x 0.7.

Next, the coating film in which the polymerizable liquid crystal compound is oriented is subjected to a curing treatment.
The method of curing treatment performed on the coating film in which the polymerizable liquid crystal compound is oriented is not particularly limited, and examples thereof include light irradiation treatment and heat treatment. Among these, from the viewpoint of manufacturing suitability, light irradiation treatment is preferred, and ultraviolet irradiation treatment is more preferred.
The irradiation conditions for the light irradiation treatment are not particularly limited, but an irradiation amount of 50 to 3000 mJ/cm ² is preferable.

In the above manufacturing method, by adjusting various conditions, the arrangement of the near-infrared absorbing dye, etc. can be adjusted, and as a result, the optical properties of the optically anisotropic film can be adjusted.
For example, by adjusting the heating temperature when aligning the polymerizable liquid crystal compound after coating the liquid crystal composition on the support to form a coating film, and the cooling temperature when cooling after heating, it is possible to The arrangement of the infrared absorbing dye can be adjusted, and as a result, the optical properties of the optically anisotropic film can be adjusted.

<Application>
The optically anisotropic film according to the embodiment of the present invention can be applied to various uses, for example, by adjusting the in-plane retardation of the optically anisotropic film, it can be used as a so-called retardation plate, preferably as a λ/4 plate. Can be used.
Note that the λ/4 plate is a plate that has a function of converting linearly polarized light of a certain wavelength into circularly polarized light (or circularly polarized light into linearly polarized light). More specifically, it is a retardation plate whose in-plane retardation Re at a predetermined wavelength λnm is 1/4 wavelength (or an odd multiple thereof).

The optically anisotropic film according to the embodiment of the present invention and the optical filter including this optically anisotropic film may be included in a display device. In this case, the optically anisotropic film and the optical filter can be used, for example, as an optical compensation filter for optically compensating a liquid crystal cell, and as an antireflection film used in a display device such as an organic electroluminescent display device.
Among them, a preferable embodiment of the optical filter is a circularly polarizing plate including an optically anisotropic film and a polarizer. This circularly polarizing plate can be suitably used as the above-mentioned antireflection film. That is, in a display device that includes a display element (for example, an organic electroluminescent display element) and a circularly polarizing plate disposed on the display element, reflected tint can be further suppressed.
Further, the optically anisotropic film of the present invention is suitably used in an optical compensation filter of an IPS (In Plane Switching) type liquid crystal display device, and prevents color change when viewed from an oblique direction and light leakage during black display. It can be improved.

As described above, examples of the optical filter including an optically anisotropic film include a circularly polarizing plate including a polarizer and an optically anisotropic film.
The polarizer may be any member (linear polarizer) that has the function of converting light into specific linearly polarized light, and mainly an absorption type polarizer can be used.
Examples of absorption polarizers include iodine polarizers, dye polarizers using dichroic dyes, and polyene polarizers. Iodine-based polarizers and dye-based polarizers include coating type polarizers and stretching type polarizers, both of which can be applied, but they are produced by adsorbing iodine or dichroic dye to polyvinyl alcohol and stretching it. Polarizers are preferred.
The relationship between the absorption axis of the polarizer and the slow axis of the optically anisotropic film is not particularly limited, but if the optically anisotropic film is a λ/4 plate and the optical filter is used as a circularly polarizing filter, the polarization The angle between the absorption axis of the child and the slow axis of the optically anisotropic film is preferably 45°±10°.

The optically anisotropic film according to the embodiment of the present invention may be used in a polarization folding optical system (so-called pancake optical system) for VR or MR. The polarization folding optical system corresponds to a conventional optical lens part. A polarization folding optical system is an optical system that uses reflection of polarized light to obtain a longer optical path length than conventional ones by combining components such as λ/4 plates, half mirrors, and reflective polarizing plates instead of conventional lenses. . A polarization folding optical system can shorten the distance between the lens and display of a VR or MR headset, making it possible to reduce the weight. The optically anisotropic film according to the embodiment of the present invention can preferably be used as a λ/4 plate. By using the optically anisotropic film according to the embodiment of the present invention, improvement in color reproducibility in VR and MR can be expected.

As explained above, this specification discloses the following optically anisotropic film, retardation plate, and optical filter.
[1] A single-layer optically anisotropic film having an ellipticity of 0.9 or more in the entire wavelength range of 430 to 680 nm.
[2] The optically anisotropic film according to [1], which has a transmittance of 97% or more at at least one of a wavelength of 830 nm and a wavelength of 850 nm.
[3] The optically anisotropic film according to [1] or [2], which contains a near-infrared absorbing dye and has a maximum absorption wavelength of less than 780 nm in a wavelength range of 650 to 1100 nm.
[4] The optically anisotropic film according to any one of [1] to [3], which contains a liquid crystal compound.
[5] The optically anisotropic film according to any one of [1] to [4], which has an average transmittance of 95% or more in the wavelength range of 430 to 680 nm.
[6] The optically anisotropic film according to any one of [1] to [5], which contains a near-infrared absorbing dye and has a maximum absorption wavelength of 750 nm or more in a wavelength range of 650 to 1100 nm.
[7] A retardation plate comprising the optically anisotropic film according to any one of [1] to [6].
[8] An optical filter comprising the optically anisotropic film according to any one of [1] to [6].

Next, the present invention will be explained in more detail with reference to Examples.
A retardation measuring device (manufactured by Otsuka Electronics, RETS-100) was used to measure retardation.
A visible absorption spectrometer (manufactured by Shimadzu Corporation, SolidSpec-3700DUV) was used to measure the absorption spectrum and spectral characteristics.

[Synthesis Example 1: Synthesis of dye A-3]

<Synthesis of compound (a1)>
Trans-4-(trans-4-propylcyclohexyl)cyclohexanecarboxylic acid 1.40g (5.55mmol), 4-(4-hydroxyphenyl)cyclohexanone 1.05g (5.52mmol), 1 -(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride 1.32 g (6.89 mmol), 4-dimethylaminopyridine 0.820 g (6.71 mmol), and dichloromethane 28.0 mL were added, and the mixture was heated under nitrogen atmosphere for 2 hours. Stir for hours. After the reaction was completed, 30 mL of saturated aqueous sodium bicarbonate solution was added, extracted twice with dichloromethane, washed with saturated brine, dried over sodium sulfate, and then the solvent was removed under reduced pressure to obtain crude compound (a1). . This was purified by column using hexane:dichloromethane:ethyl acetate=4:1:1 to obtain 2.26 g of compound (a1). (Yield 98%)

<Synthesis of compound (a2)>
Add 26 mL of THF and 2.31 g (6.74 mmol) of (methoxymethyl)triphenylphosphonium chloride to a 100 mL two-necked eggplant flask, and add 0.761 g (6.71 mmol) of t-butoxypotassium under ice cooling under a nitrogen atmosphere. ) was slowly added and stirred for 30 minutes. 2.26 g (5.32 mmol) of the compound (a1) obtained above was slowly added, stirred for 30 minutes, returned to room temperature, and stirred for 1.5 hours. After the reaction was completed, 10 mL of water and 10 mL of brine were added, extracted three times with ethyl acetate, dried over sodium sulfate, and then the solvent was removed under reduced pressure. The obtained solid was suspended in hexane, filtered to remove the solid, and the solvent was removed under reduced pressure to obtain a crude compound. The obtained compound was added to a 100 mL two-necked eggplant flask, and THF (25 mL) and 6M hydrochloric acid (2.6 mL) were added under ice cooling under a nitrogen atmosphere, and the mixture was returned to room temperature and stirred for 1 hour. After the reaction was completed, 20 mL of brine was added, extracted three times with ethyl acetate, dried over sodium sulfate, and the solvent was removed under reduced pressure to obtain a crude compound. After removing the solvent, this was purified by column using hexane:dichloromethane=2:1 to obtain 1.67 g of compound (a2). (yield 76%)

<Synthesis of compound (a3)>
10.0 g (73.4 mmol) of 2,1,3-benzothiadiazole was added to a 300 mL round bottom flask. Under ice-cooling, 200 g (2039 mmol) of concentrated sulfuric acid was added, the temperature was returned to room temperature, and the mixture was stirred for 1 hour until dissolved. Thereafter, 12.4 g (69.8 mmol) of N-bromosuccinimide was added under ice cooling again, the temperature was returned to room temperature, and the mixture was stirred for 1 hour until dissolved. After stirring for another 1 hour to complete the reaction, the reaction solution was added dropwise to 800 mL of ice water, and a solid precipitated, so the solution was left to stand and the solution was removed by decantation. Furthermore, 800 mL of water was added, the solution was left to stand and the solution was removed by decantation, and the precipitated solid was filtered to obtain unpurified compound (a3). This was suspended in 100 mL of a solution of hexane/ethyl acetate (1:1, volume ratio) and heated to 60° C. to dissolve the solid. This solution was returned to room temperature, and the precipitated solid was removed by filtration. The solid removed was dibromo. The filtrate was washed with 100 mL of saturated aqueous sodium bicarbonate solution, dried over anhydrous sodium sulfate, and then the solvent was removed under reduced pressure to obtain 9.15 g of solid. The obtained solid had a compound (a3):dibromo form=1:0.17 (mole ratio), and contained 7.42 g of compound (a3). (yield 47%)

<Synthesis of compound (a4)>
In a 500 mL three-necked round bottom flask equipped with a reflux device, 0.63 g (0.93 mmol) of PEPPSITM-IPr and 9.0 g of compound (a3) (containing 17.0 mol% of dibromo compound) obtained above were added. 15 g (Br equivalent: 46.3 mmol), 6.75 g (60.2 mmol) of t-butoxypotassium, and 200 mL of toluene were added. After degassing and nitrogen substitution, 9.57 mL (55.5 mmol) of di(2-ethylhexyl)amine was added and stirred at 100° C. for 5 hours. After the reaction was completed, solids in the reaction solution were removed by filtration through Celite, and the filtrate was concentrated to obtain unpurified compound (a4). This was purified by column chromatography using hexane/ethyl acetate (24:1, volume ratio) as a developing solution to obtain 8.53 g of compound (a4). (Yield 94%)

<Synthesis of compound (a5)>
Add 0.742 g (1.98 mmol) of compound (a4) and 7.5 mL of ethanol to a 50 mL two-necked eggplant flask, and add 0.215 g (5.68 mmol) of sodium borohydride under ice cooling under a nitrogen atmosphere. 0.157 g (0.660 mmol) of cobalt (II) chloride hexahydrate dissolved in ethanol was slowly added and stirred for 2 hours. After completion of the reaction, filter through Celite with dichloromethane, add 10 mL of saturated aqueous ammonium chloride solution and 20 mL of saturated aqueous sodium bicarbonate solution, extract 5 times with dichloromethane, dry over sodium sulfate, and remove the solvent under reduced pressure to obtain unpurified Compound (a5) was obtained. Compound (a5) was used unpurified in the next reaction.

<Synthesis of compound (a6)>
Add 0.653 g (1.88 mmol) of the compound (a5) obtained above and 10 mL of DMA to a 50 mL two-neck eggplant flask equipped with a reflux device, and add 0.196 g (1.88 mmol) of sodium bisulfite under a nitrogen atmosphere. and heated to 100°C. 1.12 g (2.55 mmol) of compound (a2) dissolved in DMA was slowly added dropwise over 15 minutes, and the mixture was stirred at 100° C. for 3 hours. After the reaction, 30 mL of saturated aqueous sodium hydroxide solution was added, extracted three times with hexane:ethyl acetate = 4:1, washed with water, dried over sodium sulfate, and the solvent was removed under reduced pressure to remove the unpurified compound. Obtained. This was purified by column using hexane:ethyl acetate=9:1 to obtain 0.977g of compound (a6). (yield 68%)

<Synthesis of dye A-3>
Add 0.977 g (1.28 mmol) of compound (a6), 25 mL of 1-butanol, and 25 mL of toluene to a 300 mL three-neck round bottom eggplant flask, and add 0.0882 g (0.765 mmol) of squaric acid under a nitrogen atmosphere. The mixture was added and refluxed for 3 hours. After the reaction was completed, the solvent was removed under reduced pressure, and the suspension was suspended in hexane and filtered to obtain unpurified dye A-3. This was purified by column using hexane:ethyl acetate=9:1 to obtain dye A-3. (yield 44%)

^1H -NMR (400MHz, CHLOROFORM-D) δ13.10 (s, 2H), 7.99 (d, J = 9.1Hz, 2H), 7.25 (d, J = 8.3Hz, 4H), 7.01 (d, J = 8.3Hz, 4H), 6.52 (d, J = 9.1Hz, 2H), 4.20-3.79 (m, 8H), 2.97 (t, J = 11.6Hz, 2H), 2.67 (t, J = 11.3Hz, 2H), 2.46-2.40 (m, H), 2.19-0.84 (m, 122H).

[Synthesis Example 2: Synthesis of dye B-1]

<Synthesis of compound (b1)>
In a 50 mL two-necked eggplant flask, trans-4-(trans-4-propylcyclohexyl)cyclohexanecarboxylic acid 1.44 g (5.71 mmol), 4-dimethylaminopyridine 0.734 g (6.01 mmol), dichloromethane 27.3 mL, 1.16 g (6.05 mmol) of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride was added, and the mixture was stirred for 20 minutes under a nitrogen atmosphere. 1.20 g (5.46 mmol) of 4-iodophenol was added and stirred for 2 hours. After the reaction, 10 mL of 1M hydrochloric acid and 10 mL of water were added, extracted 5 times with dichloromethane, washed with saturated aqueous sodium bicarbonate solution, dried over sodium sulfate, and the solvent was removed under reduced pressure to obtain unpurified compound (b1). I got it. This was purified by column using hexane:dichloromethane=1:1 to obtain 2.19 g of compound (b1). (yield 88%)

<Synthesis of compound (b2)>
1.06 g (7.66 mmol) of 3-nitroaniline and 15 mL of DMF were added to a 50 mL two-necked eggplant flask, and 1.43 g (8.03 mmol) of N-bromosuccinimide was added under a nitrogen atmosphere, followed by stirring for 1 hour. After the reaction was completed, 20 mL of a saturated aqueous sodium bicarbonate solution and 20 mL of water were added, extracted three times with hexane:ethyl acetate = 4:1, washed with water, dried over sodium sulfate, and then the solvent was removed under reduced pressure. Unpurified compound (b2) was obtained. This was purified by column using hexane:ethyl acetate=1:1 to obtain 1.56 g of compound (b2). (Yield 94%)

<Synthesis of compound (b3)>
Add 1.56 g (7.18 mmol) of compound (b2), 14 mL of acetic acid, and 14 mL of acetonitrile to a 100 mL two-necked eggplant flask, and add 0.816 g (21.6 mmol) of sodium borohydride under ice cooling under a nitrogen atmosphere. Stir for 20 minutes. 2.0 mL (21.5 mmol) of isobutyraldehyde was added, the temperature was returned to room temperature, and the mixture was stirred for 5 hours. After the reaction was completed, 10 mL of water was added and the solvent was removed under reduced pressure. After neutralizing with an aqueous sodium hydroxide solution, extracting three times with ethyl acetate, and drying over sodium sulfate, the solvent was removed under reduced pressure to obtain crude compound (b3). This was purified by column using hexane:ethyl acetate=93:7 to obtain 2.19g of compound (b3). (Yield 93%)

<Synthesis of compound (b4)>
Add 2.19 g (6.65 mmol) of compound (b3) and 22 mL of THF to a 100 mL two-necked eggplant flask, and slowly add 14 mL of vinylmagnesium chloride (1.6 mol/L, THF solution) at -40°C under a nitrogen atmosphere. Stirred for 4 hours. After the reaction was completed, 15 mL of saturated ammonium chloride aqueous solution was added, extracted three times with ethyl acetate, dried over sodium sulfate, and the solvent was removed under reduced pressure to obtain crude compound (b4). Compound (b4) was used in the next reaction without being purified.

<Synthesis of compound (b5)>
Add 2.15 g (6.65 mmol) of the compound (b4) obtained above, 44 mL of ethyl acetate, and 4.6 mL (33 mmol) of triethylamine to a 200 mL eggplant flask, add 0.53 g of Pd/C under a nitrogen atmosphere, and add hydrogen. After replacement, the mixture was stirred for 15 hours. After the reaction was completed, celite filtration was performed, and the solvent was removed under reduced pressure to obtain crude compound (b5). This was purified by column using hexane:ethyl acetate=10:1 to obtain 0.524 g of compound (b5). (yield 32%)

<Synthesis of compound (b6)>
In a 50 mL two-neck eggplant flask, compound (b5) 0.524 g (2.14 mmol), 2-norbornene 0.409 g (4.34 mmol), potassium carbonate 0.593 g (4.29 mmol), bis(acetonitrile) palladium (II) ) Add 0.056 g (0.214 mmol) of dichloride, 10.7 mL of DMA, and 0.1 mL of water, perform deaeration, add 1.94 g (4.26 mmol) of compound (b1) under nitrogen atmosphere, and heat at 70°C for 24 hours. Stir for hours. After the reaction was completed, 30 mL of water was added, extracted three times with dichloromethane, washed with brine, dried over sodium sulfate, filtered through Celite, the filtrate was collected, and the solvent was removed under reduced pressure. The obtained solid was washed with hexane, and the residue was collected to obtain unpurified compound (b6). This was purified by column using hexane:dichloromethane=1:3 to obtain 0.403 g of compound (b6). (yield 33%)

<Synthesis of dye B-1>
Dye B-1 was synthesized in the same manner as dye A-3, except that compound (a5) was changed to compound (b6) in the synthesis of dye A-3.
^1H -NMR (400MHz, CHLOROFORM-D) δ13.37 (d, J = 102.0Hz, 2H), 8.11 (d, J = 8.8Hz, 2H), 7.81 (t, J = 9 .1Hz, 4H), 7.22-7.15 (m, 4H), 6.79 (s, 2H), 6.47
(s, 2H), 3.61 (s, 8H), 2.54-2.45 (m, 2H), 2.29-2.17 (m, 8H), 1.91-1.86 (m , 4H), 1.79-1.72 (m, 8H), 1.61-1.52 (m, 4H), 1.34-1.25 (m, 4H), 1.17-1.05 (m, 18H), 0.99 (d, J=6.7Hz, 24H), 0.90-0.83
(m, 12H).

[Synthesis Example 3: Synthesis of dye C-1]

<Synthesis of compound (c1)>
Compound (c1) was synthesized in the same manner as compound (b1) except that 4-iodophenol was changed to 4-bromophenol.

<Synthesis of compound (c2)>
In a 50 mL two-necked eggplant flask, 0.684 g (1.68 mmol) of compound (c1), 8.6 mL of 1,4-dioxane, 0.450 g (5.06 mmol) of potassium acetate, [1,1'-bis(diphenylphosoid)] 0.0743 g (0.0901 mmol) of palladium (II) dichloride dichloromethane adduct was added and degassed, and 0.501 g (1.87 mmol) of bis(pinacolato) diboron was added under a nitrogen atmosphere, and the mixture was heated to 80°C. The mixture was stirred for 6 hours. After the reaction was completed, 6 mL of a saturated aqueous sodium bicarbonate solution and 10 mL of water were added, extracted three times with ethyl acetate, dried over sodium sulfate, and then the solvent was removed under reduced pressure to obtain a crude compound. This was purified by column using hexane:ethyl acetate=10:1 to obtain 0.632g of compound (c2). (yield 83%)

<Synthesis of compound (c3)>
Compound (c3) was synthesized based on the method described in paragraphs [0264] to [0267] of International Publication No. 2021/112020.

<Synthesis of compound (c4)>
In a 50 mL two-necked eggplant flask, 5.3 mL of 1,4-dioxane, 0.489 g (1.07 mmol) of compound (c3), 0.056 g (0.212 mmol) of triphenylphosphine, 0.605 g (1 0.585 g (4.23 mmol) of potassium carbonate dissolved in 0.9 mL of water was added. After degassing, 0.046 g (0.055 mmol) of [1,1'-bis(diphenylphosphino)ferrocene]palladium(II) dichloride dichloromethane adduct was added under a nitrogen atmosphere, and the mixture was stirred at 100° C. for 24 hours. After the reaction was completed, 10 mL of water was added, extracted three times with ethyl acetate, dried over sodium sulfate, filtered through Celite, and the solvent of the filtrate was removed under reduced pressure to obtain crude compound (c4). This was purified by column using hexane:ethyl acetate=20:1 to obtain 0.529 g of compound (c4). (yield 70%)

<Synthesis of dye C-1>
0.529 g (0.749 mmol) of compound (c4), 30 mL of 1-propanol, 10 mL of toluene, and 0.82 mL (7.5 mmol) of trimethyl orthoformate were added to a 100 mL two-necked eggplant flask, and 0.5 mmol of squaric acid was added under a nitrogen atmosphere. 062 g (0.54 mmol) was added and stirred at 80° C. for 1.5 hours. After the reaction was completed, the solvent was removed under reduced pressure to obtain unpurified dye C-1. This was purified by column using hexane:ethyl acetate:dichloromethane=10:1:5 to obtain 0.214g of dye C-1. (yield 38%)
¹ H-NMR (400MHz, CHLOROFORM-D) δ7.60 (dd, J=6.7, 1.9Hz, 4H), 7.22 (dd, J=6.7, 1.9Hz, 4H), 6 .04 (s, 2H), 3.32-3.21 (m, 8H), 2.48 (tt, J=12.2, 3.6Hz, 2H), 2.19 (d, J=11. 0Hz, 4H), 1.88 (d, J=9.1Hz, 8H), 1.79-1.73 (m, 8H), 1.55 (t, J=12.0Hz, 4H), 1. 40-1.21 (m, 40H), 1.17-0.96 (m, 16H), 0.89 (td, J=7.3, 3.3Hz, 32H).

[Synthesis Example 4: Synthesis of dye D-1]

<Synthesis of compound (d1)>
Compound (d1) was synthesized based on the method described in paragraphs [0272] to [0274] of International Publication No. 2021/112020.

<Synthesis of compound (d2)>
0.440 g (1.04 mmol) of compound (d1), 3.5 mL of ethanol, and 1.74 mL of a 6M aqueous sodium hydroxide solution were added to a 50 mL two-necked eggplant flask, and the mixture was refluxed for 3 hours under a nitrogen atmosphere. After the reaction was completed, the solvent was removed under reduced pressure, and 2 mL of 6M hydrochloric acid aqueous solution was added to neutralize. After adding 10 mL of water and extracting three times with dichloromethane and drying over sodium sulfate, the solvent was removed under reduced pressure to obtain crude compound (d2). Compound (d2) was used unpurified in the next reaction.

<Synthesis of compound (d3)>
Compound (d3) was synthesized by changing trans-4-(trans-4-propylcyclohexyl)cyclohexanecarboxylic acid to compound (d2) in the synthesis of compound (b1), and replacing 4-iodophenol with trans-4-( It was synthesized in the same manner as compound (b1) except that cyclohexanol (trans-4-propylcyclohexyl) was used.

<Synthesis of dye D-1>
Dye D-1 was synthesized in the same manner as dye C-1, except that compound (c4) was changed to compound (d3).
¹ H-NMR (400 MHz, CHLOROFORM-D) δ9.29 (s, 2H), 6.41 (s, 2H), 6.25 (d, J=15.7Hz, 2H), 4.81-4. 75 (m, 2H), 3.35 (d, J = 7.4Hz, 8H), 2.15 (d, J = 9.1Hz, 4H), 1.93-1.71 (m, 16H), 1.60-1.29 (m, 38H), 1.15-0.96 (m, 20H), 0.93-0.85 (m, 30H).

[Example 1-1]
The following materials were mixed in the proportions shown in Table 6 below, dissolved in dichloromethane, and dried to remove dichloromethane to obtain polymerizable liquid crystal composition 1-1.
Liquid crystal compound L-1 was synthesized based on the method described in Japanese Patent Application Publication No. 2011-207765. The liquid crystal compound L-1 is a polymerizable liquid crystal compound that exhibits inverse dispersion and exhibits a nematic phase.
Irganox 1010 manufactured by BASF was used as an antioxidant.
Irgacure 369E manufactured by BASF was used as a photopolymerization initiator.

An alignment cell manufactured by EHC Co., Ltd. with a gap of 2.3 μm maintained was heated to 160°C, and the obtained polymerizable liquid crystal composition 1-1 was injected into the cell, allowed to cool to 120°C, and nematic A phase was formed.
By irradiating UV light with a wavelength of 365 nm at 120° C. and 80 mW/cm ² ×60 seconds, polymerizable liquid crystal composition 1-1 was polymerized to obtain an optically anisotropic film.
By irradiating the optically anisotropic film with polarized light parallel to and perpendicular to the alignment direction (rubbing direction) of the liquid crystal compound and measuring the respective absorption spectra (A|| and A⊥), The maximum absorption wavelength and dichroic ratio, the average transmittance at an incident angle of 0° in the visible light region (430 to 680 nm), and the transmittance at near-infrared sensing wavelengths (830 nm and 850 nm) were calculated. Note that, as the dichroic ratio, a value expressed by A⊥/A|| at the maximum absorption wavelength was used.
Further, retardation in the visible light region (430 to 680 nm) was measured using a retardation measuring device, and ellipticity (X) was calculated using the following equations (1) and (2). Note that the ellipticity angle is θ, the retardation is Re, and the wavelength is λ.
X=tanθ (1)
sin2θ=sin(Re/λ×360°) (2)
Furthermore, an antireflection film was prepared by laminating a polarizing plate, an optically anisotropic film, and a reflecting plate in this order, and the reflectance at an incident angle of 5° in the visible light region (430 to 680 nm) was measured. The polarizing plate and the optically anisotropic film were bonded together so that the angle between their axes was 45°, and a UV-curable adhesive was used to bond each layer.

[Example 1-2 and Examples 1-4 to 1-5]
Polymerizable liquid crystal compositions 1-2 and 1-4 to 1-5 were prepared according to the same procedure as in Example 1-1, except that the dye and dye concentration were changed to the conditions shown in Table 7 below. An optically anisotropic film was obtained. Maximum absorption wavelength and dichroic ratio in the wavelength range of 650 to 1100 nm, average transmittance at an incident angle of 0° in the visible light region (430 to 680 nm), near-infrared sensing wavelength (830 nm and 850 nm) at an incident angle of 0°. In addition, the retardation in the visible light region (430 to 680 nm) was measured, and the ellipticity was calculated. Furthermore, an antireflection film was prepared in the same manner as in Example 1-1, and the reflectance at an incident angle of 5° in the visible light region (430 to 680 nm) was measured.

[Example 1-3]
The dye and dye concentration were changed to the conditions shown in Table 7 below, and the liquid crystal compound was changed to a mixture of the above liquid crystal compound L-1 (88 parts by mass) and the liquid crystal compound L-2 shown below (12 parts by mass). Except for this, polymerizable liquid crystal composition 1-3 was prepared in accordance with the same procedure as in Example 1-1, and a polymer was obtained to produce an optically anisotropic film. Maximum absorption wavelength and dichroic ratio in the wavelength range of 650 to 1100 nm, average transmittance at an incident angle of 0° in the visible light region (430 to 680 nm), near-infrared sensing wavelength (830 nm and 850 nm) at an incident angle of 0°. In addition, the retardation in the visible light region (430 to 680 nm) was measured, and the ellipticity was calculated. Furthermore, an antireflection film was prepared in the same manner as in Example 1-1, and the reflectance at an incident angle of 5° in the visible light region (430 to 680 nm) was measured.
Liquid crystal compound L-2 was synthesized based on the method described in International Publication No. 2009/148142. Note that the liquid crystal compound L-2 is a polymerizable liquid crystal compound that exhibits flat dispersibility and also exhibits a nematic phase.

Maximum absorption wavelength and dichroic ratio in the wavelength range of 650 to 1100 nm, and average transmittance at an incident angle of 0° in the visible light region (430 to 680 nm) of the optically anisotropic films obtained in Examples 1-1 to 1-5. , transmittance at an incident angle of 0° at near-infrared sensing wavelengths (830 nm and 850 nm), ellipticity calculated from retardation, and average reflection at an incident angle of 5° in the visible light range (430 to 680 nm) of the antireflection film. The rates are summarized in Table 7 below. Further, the correlation between wavelength and ellipticity in the optically anisotropic films of Examples 1-1 to 1-4 is shown in FIGS. 1 to 4, respectively.
Regarding the ellipticity, if it is 0.9 or more in the entire wavelength range of 430 to 680 nm, it is marked as ○, and if it is less than 0.9 in some region, it is marked as ×.

Examples 1-1 to 1-3 are examples, and Examples 1-4 to 1-5 are comparative examples.

From the above results, the antireflection coatings using the optically anisotropic films of Examples 1-1 to 1-3, which have an ellipticity of 0.9 or more in the visible light region (430 to 680 nm), have a wavelength of A high antireflection effect was obtained in the entire range of 430 to 680 nm. On the other hand, the antireflection films using the optically anisotropic films of Examples 1-4 and 1-5 in which the ellipticity in a part of the wavelength range of 430 to 680 nm is less than 0.9 have a high antireflection effect in that region. I couldn't get it.
Furthermore, the optically anisotropic film of Example 1-1, in which the maximum absorption wavelength in the wavelength range of 650 to 1100 nm was 750 nm or more and less than 780 nm, had an average transmittance of more than 95% in the visible light region (430 to 680 nm). High visible light transmittance was observed. Furthermore, since the transmittance at near-infrared sensing wavelengths (830 nm and 850 nm) was 97% or higher, an optically anisotropic film that did not inhibit near-infrared sensing performance was obtained. On the other hand, in the optically anisotropic film of Example 1-2, in which the maximum absorption wavelength in the wavelength range of 650 to 1100 nm is less than 750 nm, the average transmittance in the visible light region (430 to 680 nm) is less than 95%, and the visible light transmittance is low. Ta. Furthermore, in the optically anisotropic films of Examples 1-3 and 1-4, in which the maximum absorption wavelength in the wavelength range of 650 to 1100 nm is 780 nm or more, the transmittance at the near-infrared sensing wavelengths (830 nm and 850 nm) is 97%. The result was that the sensing performance of near-infrared light could be inhibited.

Although the invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. This application is a Japanese patent application filed on July 27, 2022 (Japanese patent application No. 2022-119966), a Japanese patent application filed on November 2, 2022 (Japanese patent application No. 2022-176665), and a Japanese patent application filed on November 2, 2022. It is based on the Japanese patent application (Japanese Patent Application No. 2022-176666), the contents of which are incorporated herein by reference.

The optically anisotropic film of the present invention is useful, for example, as a retardation plate (1/4 wavelength plate) exhibiting excellent reverse wavelength dispersion.

Claims

A single-layer optically anisotropic film with an ellipticity of 0.9 or more in the entire wavelength range of 430 to 680 nm.
The optically anisotropic film according to claim 1, having a transmittance of 97% or more at at least one of a wavelength of 830 nm and a wavelength of 850 nm.
The optically anisotropic film according to claim 1, which contains a near-infrared absorbing dye and has a maximum absorption wavelength of less than 780 nm in a wavelength range of 650 to 1100 nm.
The optically anisotropic film according to claim 1, which contains a near-infrared absorbing dye, has a transmittance of 97% or more at at least one of a wavelength of 830 nm and a wavelength of 850 nm, and has a maximum absorption wavelength of less than 780 nm in a wavelength range of 650 to 1100 nm. .
The optically anisotropic film according to claim 4, comprising a liquid crystal compound.
The optically anisotropic film according to claim 1, having an average transmittance of 95% or more in the wavelength range of 430 to 680 nm.
The optically anisotropic film according to claim 1, which contains a near-infrared absorbing dye and has a maximum absorption wavelength of 750 nm or more in a wavelength range of 650 to 1100 nm.
The optically anisotropic film according to claim 1, which contains a near-infrared absorbing dye, has an average transmittance of 95% or more in the wavelength range of 430 to 680 nm, and has a maximum absorption wavelength of 750 nm or more in the wavelength range of 650 to 1100 nm.
The optically anisotropic film according to claim 8, comprising a liquid crystal compound.
A retardation plate comprising the optically anisotropic film according to any one of claims 1 to 9.
An optical filter comprising the optically anisotropic film according to any one of claims 1 to 9.