Optically anisotropic layer and method for producing optically anisotropic layer

Abstract

Provided are an optically anisotropic layer having excellent antireflection properties, and a method for producing the optically anisotropic layer. This optically anisotropic layer is formed using a composition containing a liquid crystal compound, and has at least one region in which the birefringence ([Delta] n) changes continuously in the thickness direction and the wavelength dispersion is constant in the thickness direction.

Description

Technical Field

[0001] The present invention relates to an optically anisotropic layer and a method for manufacturing the optically anisotropic layer. Background Art

[0002] Optically anisotropic layers formed using a composition containing a liquid crystal compound are used for various purposes such as diffraction elements and wavelength selective reflection layers. The optically anisotropic layer is formed by aligning the liquid crystal compound in a predetermined alignment state.

[0003] Examples of the optically anisotropic layer include a λ / 2 plate and a λ / 4 plate described in Patent Document 1.

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Patent No. 2007-188033 Summary of the Invention

[0007] Problems to be Solved by the Invention

[0008] On the other hand, in recent years, as a required characteristic of the optically anisotropic layer, it is required to suppress reflection on the surface of the optically anisotropic layer adjacent to air or other components when light is incident on the optically anisotropic layer. Hereinafter, the suppression of reflection on the surface of the optically anisotropic layer is also referred to as "excellent antireflection property".

[0009] The present inventors studied the above characteristics of the known optically anisotropic layer described in Patent Document 1 and found that further improvement is required.

[0010] An object of the present invention is to provide an optically anisotropic layer having excellent antireflection property.

[0011] Another object of the present invention is to provide a method for manufacturing an optically anisotropic layer.

[0012] Means for Solving the Problems

[0013] As a result of intensive studies on the problems of the prior art, the present inventors found that the above problems can be solved by the following structure.

[0014] (1) An optically anisotropic layer formed using a composition containing a liquid crystal compound, wherein

[0015] the optically anisotropic layer has at least one region in which the birefringence Δn continuously changes in the thickness direction and the wavelength dispersion is constant in the thickness direction.

[0016] (2) The optical anisotropic layer according to (1), wherein

[0017] in the above region, the birefringence Δn gradually decreases in the direction from one surface of the optical anisotropic layer toward the other surface.

[0018] (3) The optical anisotropic layer according to (1) or (2), wherein

[0019] the above optical anisotropic layer has two such regions,

[0020] one of the two regions is located at a position on either surface side of the two surfaces of the optical anisotropic layer,

[0021] in one region, the birefringence Δn gradually decreases in the direction from the center position of the film thickness of the optical anisotropic layer toward one surface,

[0022] the other of the two regions is located at a position on the other surface side of the two surfaces of the optical anisotropic layer,

[0023] in the other region, the birefringence Δn gradually decreases in the direction from the center position of the film thickness of the optical anisotropic layer toward the other surface.

[0024] (4) The optical anisotropic layer according to any one of (1) to (3), wherein

[0025] the thickness of the above region is 0.5 μm or more.

[0026] (5) The optical anisotropic layer according to any one of (1) to (4), wherein

[0027] in the above region, the maximum birefringence Δn max and the minimum birefringence Δn min have a ratio of 2.0 or more.

[0028] (6) The optical anisotropic layer according to any one of (1) to (5), which is a layer formed by fixing a liquid crystal compound having a cholesteric orientation.

[0029] (7) The optical anisotropic layer according to any one of (1) to (6), wherein

[0030] the liquid crystal compound has a cationic polymerizable group.

[0031] (8) The optical anisotropic layer according to any one of (1) to (7), wherein

[0032] the composition contains a phenolic compound.

[0033] (9) The optical anisotropic layer according to any one of (1) to (8), wherein

[0034] the composition contains an ultraviolet absorber.

[0035] (10) The optical anisotropic layer according to any one of (1) to (9), which has a liquid crystal alignment pattern in which the orientation of the optical axis derived from the liquid crystal compound continuously rotates and changes along at least one in-plane direction.

[0036] (11) A method for manufacturing an optical anisotropic layer, which is a method for manufacturing the optical anisotropic layer according to any one of (1) to (10), and includes:

[0037] Step 1: Using a composition containing a liquid crystal compound having a polymerizable group to form a coating film, and aligning the liquid crystal compound in the formed coating film;

[0038] Step 2: Polymerizing the liquid crystal compound to form a region where the polymerization rate of the liquid crystal compound continuously changes in the thickness direction of the coating film; and

[0039] Step 3: Performing a heat treatment on the coating film obtained in Step 2 to form a region where the birefringence Δn continuously changes in the thickness direction and the wavelength dispersion is constant in the thickness direction.

[0040] Advantages of the Invention

[0041] According to the present invention, an optical anisotropic layer having excellent antireflection properties can be provided.

[0042] According to the present invention, a method for manufacturing an optical anisotropic layer can be provided. Description of the Drawings

[0043] Figure 1 is a cross-sectional view showing an example of the optical anisotropic layer of the present invention.

[0044] Figure 2 is a partially enlarged cross-sectional view of the optical anisotropic layer for explaining a region where the birefringence Δn continuously changes in the thickness direction and the wavelength dispersion is constant in the thickness direction.

[0045] Figure 3 is a cross-sectional view showing another example of the optical anisotropic layer of the present invention.

[0046] Figure 4 is a cross-sectional view showing another example of the optical anisotropic layer of the present invention.

[0047] Figure 5 is Figure 4 a top view of the optical anisotropic layer shown.

[0048] Figure 6 This is a top view showing another example of the optically anisotropic layer of the present invention.

[0049] Figure 7 This is a diagram for showing the manufacturing steps of the optically anisotropic layer of the present invention.

[0050] Figure 8 This is a diagram conceptually showing an example of an exposure apparatus for producing a photo-alignment film.

[0051] Figure 9 This is a diagram showing an example of the thickness-direction birefringence distribution in the case where the wavelength dispersion of the optically anisotropic layer is constant in the thickness direction.

[0052] Figure 10 This is a diagram showing an example of the thickness-direction birefringence distribution in the case where the wavelength dispersion of the optically anisotropic layer is not constant in the thickness direction. Detailed Description of the Invention

[0053] Hereinafter, the present invention will be described in detail.

[0054] The description of the constituent elements described below is based on representative embodiments of the present invention, but the present invention is not limited to such embodiments.

[0055] In this specification, the numerical range expressed by “~” means a range including the numerical values described before and after “~” as the lower limit value and the upper limit value.

[0056] Moreover, in this specification, each component may be a single substance corresponding to each component, or two or more substances may be used simultaneously. Here, in the case of using two or more substances for each component, the content of the component represents the total content of the substances used simultaneously, unless otherwise specified.

[0057] In this specification, “(meth)acrylate” is used in the meaning of “any one or both of acrylate and methacrylate”.

[0058] In this specification, the solid component means a component that forms the optically anisotropic layer and does not include a solvent. The component that forms the optically anisotropic layer may be a component whose chemical structure changes by reaction (polymerization) when forming the optically anisotropic layer. And, if it is a component that forms the optically anisotropic layer, even if its property is liquid, it can be regarded as a solid component.

[0059] Unless otherwise specified, the bonding direction of the divalent group marked in this specification is not restricted. For example, when Y in the compound represented by the formula "X-Y-Z" is -COO-, Y can be -CO-O- or -O-CO-. And the above compound can be "X-CO-O-Z" or "X-O-CO-Z".

[0060] In this specification, the birefringence is obtained by measuring Re(λ) and dividing Re(λ) by the thickness.

[0061] In this specification, Re(λ) and Rth(λ) respectively represent the in-plane retardation and the retardation in the thickness direction at the wavelength λ. When there is no special description, the wavelength λ is set to 550 nm.

[0062] In this specification, Re(λ) and Rth(λ) are the values measured at the wavelength λ in AxoScan (manufactured by Axometrics). The following are calculated by inputting the average refractive index ((nx + ny + nz) / 3) and the film thickness (d (μm)) into AxoScan.

[0063] In-plane slow axis direction (°)

[0064] Re(λ) = R0(λ)

[0065] Rth(λ) = ((nx + ny) / 2 - nz) × d

[0066] In addition, R0(λ) is represented by the value calculated by AxoScan and refers to Re(λ).

[0067] In this specification, for the refractive indices nx, ny, and nz, a Abbe refractometer (NAR-4T, manufactured by ATA GO CO., LTD.) is used, and a sodium lamp (λ = 589 nm) is used as the light source for measurement. And when measuring the wavelength dependence, it can be measured in combination with an interference filter by a multi-wavelength Abbe refractometer DR-M2 (manufactured by ATAGO CO., LTD.).

[0068] And 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 indices of the main optical films are exemplified below: cellulose acylate (1.48), cycloolefin polymer (1.52), polycarbonate (1.59), polymethyl methacrylate (1.49), and polystyrene (1.59).

[0069] As a characteristic point of the optically anisotropic layer of the present invention, the following can be cited: having a region where the birefringence Δn continuously changes in the thickness direction and the wavelength dispersion is constant in the thickness direction (hereinafter, also simply referred to as "specific region").

[0070] In the case of a conventional optically anisotropic layer, when light is incident on the optically anisotropic layer, reflection easily occurs on the surface of the optically anisotropic layer. Regarding the reason for this problem, taking an optically anisotropic layer containing a uniformly aligned liquid crystal compound as an example, the liquid crystal compound is uniformly aligned on the surface of the optically anisotropic layer, so there are a direction with a high refractive index in the slow axis direction and a direction with a low refractive index in the fast axis direction. Assuming that the surface of the optically anisotropic layer is adjacent to air, the difference between the refractive index in the slow axis direction of the optically anisotropic layer and the refractive index of air is greater than the difference between the refractive index in the fast axis direction of the optically anisotropic layer and the refractive index of air, and reflection of polarized light in the slow axis direction is more likely to occur. That is, when the birefringence Δn on the surface of the optically anisotropic layer is large, reflection is likely to occur in any direction.

[0071] In contrast, the optically anisotropic layer of the present invention solves the above problems by having the above specific region. For example, when the optically anisotropic layer of the present invention has a specific region where the birefringence Δn gradually decreases toward the air side, the refractive index of the optically anisotropic layer in a specific direction with a large refractive index difference from air gradually decreases toward the air side. As a result, the generation of reflection is suppressed at the interface between air and the optically anisotropic layer. Thus, in the present invention, by providing a specific region, a sharp refractive index difference can be suppressed, and as a result, the antireflection property is improved.

[0072] Moreover, in the optically anisotropic layer of the present invention, the wavelength dispersion in the specific region is constant in the thickness direction. By having a constant wavelength dispersion, for example, the birefringence at the interface can be made close to zero in all wavelength regions. In this case, excellent antireflection ability can be obtained when in contact with an isotropic medium. Regarding the reason, it is explained using Figure 9 and Figure 10 for illustration.

[0073] Figure 9 FIG _____ shows an example of the birefringence distribution in the thickness direction when the wavelength dispersion of the optically anisotropic layer is constant in the thickness direction. Figure 10 FIG _____ shows an example of the birefringence distribution in the thickness direction when the wavelength dispersion of the optically anisotropic layer is not constant in the thickness direction.

[0074] In Figure 9 and Figure 10Among them, the straight line 52 represents the birefringence at a short wavelength (e.g., 450 nm), the straight line 54 represents the birefringence at a long wavelength (e.g., 550 nm), and the point 56 represents the position of the interface on the side with a small birefringence.

[0075] As can be seen from the comparison with Figure 9 and Figure 10 , when the wavelength dispersion is constant, in all wavelength regions, the birefringence of the layer interface can be set to zero. Therefore, for example, when the optically anisotropic layer is in contact with an isotropic medium, no birefringence difference occurs at its interface, and thus excellent antireflection ability can be obtained. In addition, it is considered that when the optically anisotropic layer is composed of cholesteric-oriented liquid crystal, the side lobes of the cholesteric liquid crystal can be reduced in all wavelength regions, and thus excellent antireflection ability can be obtained.

[0076] Moreover, when the wavelength dispersion is constant, compared with the case where the wavelength dispersion is not constant, the slope of the straight line 52 representing the birefringence at a short wavelength is smaller, that is, the change in birefringence inside the optically anisotropic layer is gentle. As a result of the research, in order to exhibit the antireflection ability, it is preferable that the change in birefringence inside the optically anisotropic layer is gentle. Especially when the optically anisotropic layer is composed of cholesteric-oriented liquid crystal, when the birefringence change is gentle, the side lobe reduction effect is significant. Therefore, it is considered that excellent antireflection ability can be obtained when the wavelength dispersion is constant.

[0077] In addition, as will be described later, the above-mentioned wavelength dispersion characteristics can also be achieved by forming a specific region using one kind of liquid crystal compound.

[0078] Moreover, when the optically anisotropic layer is a reflective optically anisotropic layer such as a cholesteric liquid crystal layer (a layer containing a cholesteric-oriented liquid crystal compound), the generation of side lobes is suppressed by having a specific region. In addition, as shown in Figure 1 International Publication No. 2022 / 239835, the side lobe refers to a part where the reflectance becomes relatively large at a wavelength near the outside of the reflection wavelength band. When such side lobes are generated, light of a wavelength that should not be reflected is reflected, which is not preferable.

[0079] <Optically anisotropic layer>

[0080] Figure 1 The cross-sectional view showing an example of the optically anisotropic layer of the present invention is shown in.

[0081] As Figure 1 shown, the optically anisotropic layer 10A has a specific region 12A on one surface S1 side. In the specific region 12A, the birefringence Δn gradually decreases toward the surface S1 side, and the wavelength dispersion is constant in the thickness direction.

[0082] The specific region 12A is disposed closer to one surface S1 side with reference to the central position of the film thickness of the optically anisotropic layer. In the specific region 12A, the birefringence Δn gradually decreases in the direction from the central position of the film thickness of the optically anisotropic layer toward one surface S1.

[0083] Hereinafter, first, the specific region 12A will be described in detail.

[0084] The optically anisotropic layer of the present invention has a region where the birefringence Δn continuously changes in the thickness direction and the wavelength dispersion is constant in the thickness direction. The above specific region 12A corresponds to one mode of this region.

[0085] In the optically anisotropic layer of the present invention, the continuous change of the birefringence Δn in the thickness direction means that the birefringence Δn of a region with a thickness of 0.1 μm continuously changes in the thickness direction. That is, the optically anisotropic layer is divided into regions with a thickness of 0.1 μm each, and the birefringence Δn of each region is calculated. As long as the birefringence Δn continuously changes in the thickness direction, one necessary condition of the specific region is satisfied.

[0086] More specifically, first, as Figure 2 shown in the optically anisotropic layer 10B, the optically anisotropic layer 10B is divided into regions with a thickness of 0.1 μm each. In Figure 2 , as a part of the divided regions (divided regions), the divided regions 14a to 14d are shown. Next, the birefringence Δn of the divided regions including each of the divided regions 14a to 14d is calculated respectively.

[0087] There is no particular limitation on the method for calculating the birefringence Δn of each divided region. As an example, there is the following method: a part of the optically anisotropic layer is etched, and the birefringence Δn is calculated by the difference in the phase difference (Re) before and after etching. For example, a sample 1 obtained by etching and removing the divided region 14a from the surface of the optically anisotropic layer 10B and a sample 2 obtained by removing the divided regions 14a and 14b are prepared. Next, the phase differences of the samples 1 and 2 are calculated using Axoscan (manufactured by Axometrics). Next, the phase difference of the divided region 14b is calculated based on the difference in the phase differences of the samples 1 and 2. Since the phase difference is equivalent to the product of the birefringence Δn and the thickness, the birefringence Δn of the divided region 14b can be calculated based on the calculated phase difference of the divided region 14b.

[0088] Moreover, in the case where the liquid crystal compound in the optically anisotropic layer has a cholesteric orientation or the optically anisotropic layer has a liquid crystal alignment pattern described later, the following method is used to determine whether the birefringence Δn continuously changes.

[0089] First, regarding Samples 1 and 2 produced through the above steps, phase difference measurements were performed using Axoscan with respect to incident light from the normal direction. For the detected slow axis and fast axis, phase difference measurements were carried out in the slow axis direction and at a polar angle of -40° or 40°, and further, phase difference measurements were performed in the fast axis direction and at a polar angle of -40° or 40°. That is, phase difference measurements were made from the above four directions, and the average value of the obtained measurement values was calculated as the tilt direction phase difference Re(40). Next, the difference between the tilt direction phase difference Re(40) of Sample 1 and the tilt direction phase difference Re(40) of Sample 2 was calculated to obtain the tilt direction phase difference Re(40) of the divided region 14b. Such operations were performed on each divided region to obtain the tilt direction phase difference Re(40) of each divided region. Usually, the phase difference is proportional to the birefringence Δn. Therefore, when the tilt direction phase difference Re(40) of each divided region changes continuously, it is possible to stipulate that the birefringence Δn of each divided region changes continuously.

[0090] In the present invention, the birefringence Δn refers to the birefringence Δn at a wavelength of 550 nm.

[0091] Moreover, the birefringence Δn refers to the difference between the refractive index in the direction where the refractive index in the plane is the largest and the refractive index in the direction orthogonal to the direction where the refractive index is the largest.

[0092] Furthermore, in the optically anisotropic layer of the present invention, the wavelength dispersion being constant in the thickness direction within a specific region means that in the thickness direction determined by the above method, the wavelength dispersion in the region (hereinafter, also referred to as the Δn change region) including the region (region L) above the average birefringence of the Δn change region and the wavelength dispersion in the region (region S) including the region within the Δn change region and less than the average birefringence of the Δn change region are the same.

[0093] The wavelength dispersion in the region (region L) above the average birefringence of the Δn change region and the wavelength dispersion in the region (region S) less than the average birefringence of the Δn change region can be calculated through the following steps a) to c).

[0094] a) The Δn change region was divided into regions with a thickness of 0.1 μm each. Referring to the method for calculating the birefringence Δn of the above divided regions, the birefringence Δn450 at a wavelength of 450 nm and the birefringence Δn550 at a wavelength of 550 nm of each divided region were calculated.

[0095] b) Calculate the average value Δn550ave of the birefringence Δn550 at a wavelength of 550 nm for each divided region, and determine the divided region (region L) where the birefringence Δn550 is above the average value Δn550ave and the divided region (region S) where the birefringence Δn550 is less than the average value Δn550ave.

[0096] c) Calculate the average value Δn450L of the birefringence Δn450 in region L and the average value Δn550L of the birefringence Δn550 in region L respectively, and calculate the ratio of the two (average value Δn450L / average value Δn550L) as the wavelength dispersion Δn450L / Δn550L of region L. Similarly, calculate the average value Δn450S of the birefringence Δn450 in region S and the average value Δn550S of the birefringence Δn550 in region S respectively, and calculate the ratio of the two (average value Δn450S / average value Δn550S) as the wavelength dispersion Δn450S / Δn550S of region S.

[0097] In the present invention, the wavelength dispersion being constant in the thickness direction means that the wavelength dispersion Δn450S / Δn550S of region S is within the range of ±20% with respect to the wavelength dispersion Δn450L / Δn550L of region L, preferably within ±10%, more preferably within ±5%. That is, the wavelength dispersion being constant in the thickness direction means that the A value calculated by the following formula is within the range of -20 to 20%. If the A value is within this numerical range, it is assumed that the wavelength dispersion in the region (region L) above the average birefringence of the Δn change region is consistent with the wavelength dispersion in the region (region S) included in the Δn change region and less than the average birefringence of the Δn change region.

[0098] A value = { (wavelength dispersion Δn450S / Δn550S - wavelength dispersion Δn450L / Δn550L) / wavelength dispersion Δn450L / Δn550L} × 100

[0099] In addition, in the optically anisotropic layer, when the liquid crystal compound is in a cholesteric orientation or when the optically anisotropic layer has a liquid crystal alignment pattern described later, calculate the tilt direction phase difference Re(40, 450) at a polar angle of 40° at a wavelength of 450 nm and the tilt direction phase difference Re(40, 550) at a polar angle of 40° at a wavelength of 550 nm for each divided region, and by the same method as in b) and c) above, use the tilt direction phase difference instead of the birefringence, whereby the wavelength dispersion constancy can be confirmed.

[0100] In addition, the tilt direction phase difference Re(40, 450) at a polar angle of 40° at a wavelength of 450 nm is calculated by the following method. First, for the slow axis and the fast axis in the divided region detected by Axoscan, the phase difference at a wavelength of 450 nm is measured in the slow axis direction at a polar angle of -40° or 40°, and further the phase difference at a wavelength of 450 nm is measured in the fast axis direction at a polar angle of -40° or 40°, and the average value of the obtained measured values is calculated as the above tilt direction phase difference Re(40, 450).

[0101] Moreover, the tilt direction phase difference Re(40, 550) at a polar angle of 40° at a wavelength of 550 nm is calculated by the following method. First, for the slow axis and the fast axis in the divided region detected by Axoscan, the phase difference at a wavelength of 550 nm is measured in the slow axis direction at a polar angle of -40° or 40°, and further the phase difference at a wavelength of 550 nm is measured in the fast axis direction at a polar angle of -40° or 40°, and the average value of the obtained measured values is calculated as the above tilt direction phase difference Re(40, 550).

[0102] If there is a region where the birefringence Δn of the divided region of the optically anisotropic layer 10B calculated by the above steps continuously changes and the wavelength dispersion is constant, then this region is set as a specific region. For example, in the case where the birefringence Δn continuously changes and the wavelength dispersion is constant in the divided regions 14a to 14d, the region composed of the divided regions 14a to 14d corresponds to the specific region.

[0103] In Figure 1 In the shown specific region 12A, the birefringence Δn gradually decreases toward the surface S1 side, and the wavelength dispersion is constant in the thickness direction. That is, in the specific region 12A, the specific region 12A is divided into regions with a thickness of 0.1 μm each, and when the birefringence Δn of each divided region is calculated, the birefringence Δn of the divided region gradually decreases toward the surface S1 side. And, in the specific region 12A, when the wavelength dispersion of each divided region is calculated, the wavelength dispersion is constant.

[0104] In addition, in Figure 1 , the mode of the optically anisotropic layer 10A having a specific region 12A where the birefringence Δn gradually decreases toward the surface S1 side and the wavelength dispersion is constant in the thickness direction is described, but the present invention is not limited to this mode.

[0105] For example, the optically anisotropic layer of the present invention may have a specific region where the birefringence Δn gradually increases toward either one of the two main surfaces of the optically anisotropic layer and the wavelength dispersion is constant in the thickness direction.

[0106] That is, in a specific region of the optically anisotropic layer of the present invention, the birefringence Δn can gradually decrease or gradually increase. Also, the direction of gradual increase or gradual decrease is not particularly limited.

[0107] Also, in Figure 1 , the specific region 12A is disposed in the thickness direction from the surface S1, but the position of the specific region in the optically anisotropic layer is not particularly limited. For example, in the total film thickness of the optically anisotropic layer, a specific region may be formed.

[0108] Also, in Figure 1 , the optically anisotropic layer 10A has one specific region 12A, but the optically anisotropic layer may also have two specific regions.

[0109] For example, Figure 3 the optically anisotropic layer 10B shown has a specific region 12A and a specific region 12B. As described above, the specific region 12A is a region disposed on the surface S1 side and having a birefringence Δn that gradually decreases toward the surface S1 side and having a constant wavelength dispersion in the thickness direction.

[0110] The specific region 12B is a region disposed on the surface S2 side and having a birefringence Δn that gradually decreases toward the surface S2 side and having a constant wavelength dispersion in the thickness direction. That is, the specific region 12B is disposed closer to the other surface S2 side with respect to the center position of the film thickness of the optically anisotropic layer, and in the specific region 12B, the birefringence Δn gradually decreases in the direction from the center position of the film thickness of the optically anisotropic layer toward one surface S2.

[0111] In the case where the optically anisotropic layer is a cholesteric liquid crystal layer, if it has two specific regions as shown in Figure 3 , the generation of side lobes can be suppressed as described above.

[0112] Also, in the specific region of the optically anisotropic layer of the present invention, the ratio of the maximum birefringence Δn max to the minimum birefringence Δn min is not particularly limited, and is usually 1.2 or more. From the aspect that the antireflection property of the optically anisotropic layer is more excellent (hereinafter, also simply referred to as "the aspect where the effect of the present invention is more excellent"), it is preferably 2.0 or more. The upper limit is not particularly limited and can be infinite (i.e., Δn min is 0), and it is often 100 or less, and more often 20 or less.

[0113] As the birefringence Δn min in the specific region and the birefringence Δn maxCalculation method: Calculate the birefringence Δn of each of the above-mentioned divided regions, and set the maximum value among the birefringences Δn of the divided regions as the birefringence Δn max , and set the minimum value among the birefringences Δn of the divided regions as the birefringence Δn min .

[0114] The above-mentioned birefringence Δn min There is no particular limitation on its magnitude. From the aspect of more excellent effects of the present invention, it is preferably 0.00 to 0.20, more preferably 0.00 to 0.10, and further preferably 0.00 to 0.05.

[0115] The above-mentioned birefringence Δn max There is no particular limitation on its magnitude. From the aspect of more excellent effects of the present invention, it is preferably 0.005 to 0.50, more preferably 0.01 to 0.45, and further preferably 0.03 to 0.40.

[0116] There is no particular limitation on the thickness of the specific region in the optically anisotropic layer. However, from the aspect of more excellent antireflection property of the optically anisotropic layer (hereinafter, also simply referred to as "the aspect of more excellent effects of the present invention"), it is preferably 0.3 μm or more, and more preferably 0.5 μm or more. There is no particular limitation on the upper limit, and the total film thickness of the optically anisotropic layer can be cited.

[0117] There is no particular limitation on the ratio of the thickness of the specific region to the total film thickness of the optically anisotropic layer. From the aspect of more excellent effects of the present invention, it is preferably 20 to 100%, more preferably 60 to 100%, and further preferably the entire layer is a specific region.

[0118] There is no particular limitation on the thickness of the optically anisotropic layer, but it is more preferably 0.5 μm or more, and further preferably 1.5 μm or more. There is no particular limitation on the upper limit, but it is preferably 20 μm or less, and more preferably 15 μm or less.

[0119] There is no particular limitation on the alignment state of the liquid crystal compound in the optically anisotropic layer, and known alignment states can be cited. As the alignment state, for example, homogeneous alignment, vertical alignment, mixed alignment, cholesteric alignment, twisted alignment, and tilted alignment can be cited. In addition, the above-mentioned twisted alignment means an alignment state in which the liquid crystal compound is twisted from one main surface of the optically anisotropic layer to the other main surface with the thickness direction of the optically anisotropic layer as the rotation axis. In the twisted alignment, the twist angle of the liquid crystal compound (the twist angle of the alignment direction of the liquid crystal compound) is usually more than 0° and 360° or less.

[0120] The optically anisotropic layer is preferably a layer formed by fixing an aligned liquid crystal compound. When the liquid crystal compound has a polymerizable group, the alignment state of the liquid crystal compound can be easily fixed by the curing treatment described later.

[0121] In addition, the "fixed" state is a state in which the alignment of the liquid crystal compound is maintained. Specifically, it is preferably a state in which the layer has no fluidity and the alignment pattern does not change due to an external field or external force, and can stably and continuously maintain the fixed alignment pattern at a temperature in the range of usually 0 to 50 °C, and more severely -30 to 70 °C.

[0122] The optically anisotropic layer may have a liquid crystal alignment pattern in which the orientation of the optical axis derived from the liquid crystal compound continuously rotates and changes along at least one direction in the plane.

[0123] Hereinafter, the liquid crystal alignment pattern will be described in detail.

[0124] Figure 5 shows Figure 4 A plan view of the optically anisotropic layer shown. Figure 4 is a cross-sectional view taken along line A-A in Figure 5 Here.

[0125] In addition, the plan view means a view of observing the optically anisotropic layer 10C from above in Figure 4 That is, Figure 5 is a view of observing the optically anisotropic layer 10C from the thickness direction.

[0126] In addition, in Figure 5 only the liquid crystal compound 30 on the surface side of the optically anisotropic layer 10C is shown in order to clearly show the structure of the optically anisotropic layer 10C. However, as Figure 4 shown, the optically anisotropic layer 10C has a structure in which the liquid crystal compound 30 is laminated in the thickness direction.

[0127] Figure 4 The optically anisotropic layer 10C shown has a predetermined liquid crystal alignment pattern in which the orientation of the optical axis derived from the liquid crystal compound 30 rotates in one direction in the plane.

[0128] The optically anisotropic layer 10C is formed using a composition containing the liquid crystal compound described later.

[0129] As Figure 5 shown, the optically anisotropic layer 10C has a liquid crystal alignment pattern in which the orientation of the optical axis 30A derived from the liquid crystal compound 30 continuously rotates counterclockwise in one direction indicated by the arrow X in the plane of the optically anisotropic layer 10C and changes. In addition, in Figure 5In this case, the orientation of the optical axis 30A derived from the liquid crystal compound 30 rotates counterclockwise. However, the present invention is not limited to this manner, and it may also rotate clockwise.

[0130] In addition, the optical axis 30A derived from the liquid crystal compound 30 is the axis with the highest refractive index in the liquid crystal compound 30. For example, when the liquid crystal compound 30 is a rod-shaped liquid crystal compound, the optical axis 30A is along the long axis direction of the rod shape.

[0131] In the following description, "a direction indicated by the arrow X" will also be simply referred to as "the arrow X direction". Also, in the following description, the optical axis 30A derived from the liquid crystal compound 30 will also be referred to as "the optical axis 30A of the liquid crystal compound 30" or "the optical axis 30A".

[0132] In the optically anisotropic layer 10C, the liquid crystal compounds 30 are two-dimensionally oriented in a plane parallel to the arrow X direction and the Y direction orthogonal to the arrow X direction in the optically anisotropic layer 10C respectively. In addition, in Figure 4 this case, the Y direction becomes the direction perpendicular to the paper surface.

[0133] As described above, the optically anisotropic layer 10C has a liquid crystal alignment pattern in which the orientation of the optical axis 30A derived from the liquid crystal compound 30 changes while continuously rotating along the arrow X direction in the plane of the optically anisotropic layer 10C.

[0134] The orientation of the optical axis 30A of the liquid crystal compound 30 changes while continuously rotating in the arrow X direction (a specified one direction). Specifically, it means that the angle formed by the optical axis 30A of the liquid crystal compound 30 arranged along the arrow X direction and the arrow X direction changes from θ to θ + 180° or θ - 180° in sequence according to the position in the arrow X direction.

[0135] In addition, the angle difference between the optical axes 30A of the liquid crystal compounds 30 adjacent to each other in the arrow X direction is preferably 45° or less, and more preferably 15° or less.

[0136] On the other hand, in the liquid crystal compounds 30 forming the optically anisotropic layer 10C, the liquid crystal compounds 30 with equal orientations of the optical axis 30A are arranged at equal intervals in the Y direction orthogonal to the arrow X direction, that is, in the Y direction orthogonal to the direction in which the optical axis 30A continuously rotates.

[0137] In other words, in the liquid crystal compounds 30 forming the optically anisotropic layer 10C, between the liquid crystal compounds 30 arranged in the Y direction, the angles formed by the orientations of the optical axis 30A and the arrow X direction are equal.

[0138] In the liquid crystal alignment pattern of this liquid crystal compound 30, the length (distance) for rotating the optical axis 30A of the liquid crystal compound 30 by 180° in the arrow X direction in which the orientation of the in-plane optical axis 30A continuously rotates and changes is defined as the length Λ of one period in the liquid crystal alignment pattern. In other words, the length of one period in the liquid crystal alignment pattern is defined by the distance from the angle formed by the optical axis 30A of the liquid crystal compound 30 and the arrow X direction reaching θ to θ + 180°.

[0139] That is, the distance between the centers in the arrow X direction of two liquid crystal compounds 30 having equal angles with respect to the arrow X direction is defined as the length Λ of one period. Specifically, as Figure 5 shown, the distance between the centers in the arrow X direction of two liquid crystal compounds 30 in which the direction of the arrow X is consistent with the direction of the optical axis 30A is defined as the length Λ of one period. In the following description, this length Λ of one period is also referred to as "one period Λ".

[0140] In the optically anisotropic layer 10C, the liquid crystal alignment pattern of the optically anisotropic layer 10C repeats this one period Λ in one direction in which the orientation of the optical axis 30A, i.e., the arrow X direction, continuously rotates and changes.

[0141] As described above, in the optically anisotropic layer 10C, among the liquid crystal compounds 30 arranged in the Y direction, the angles formed by the optical axis 30A and the arrow X direction (one direction in which the optical axis of the liquid crystal compound 30 rotates) are equal. The region where the liquid crystal compounds 30 having equal angles formed by the optical axis 30A and the arrow X direction are arranged in the Y direction is defined as region R.

[0142] In this case, it is preferable that the value of the in-plane retardation (Re) in each region R is half a wavelength, i.e., λ / 2. Regarding these in-plane retardations, they are calculated by the product of the birefringence Δn of region R and the thickness of the optically anisotropic layer. Among them, the refractive index anisotropy of region R in the optically anisotropic layer is defined as the refractive index difference defined by the difference between the refractive index in the direction of the slow axis in the plane of region R and the refractive index in the direction orthogonal to the direction of the slow axis. That is, the birefringence Δn of region R is equal to the difference between the refractive index of the liquid crystal compound 30 in the direction of the optical axis 30A and the refractive index of the liquid crystal compound 30 in the direction perpendicular to the optical axis 30A in the plane of region R.

[0143] The above 180° rotation period in the optically anisotropic layer 10C does not need to be the same throughout the entire surface. That is, regions with different lengths (the length Λ of one period) of the 180° rotation period can exist in the plane.

[0144] The minimum value of the length of one cycle of the length in which the orientation of the optical axis of the liquid crystal compound rotates 180° in the plane is preferably 20 μm or less, more preferably 5 μm or less, and still more preferably 2 μm or less. There is no particular limitation on the lower limit, but it is mostly 0.5 μm or more.

[0145] In addition, it is sufficient to have a liquid crystal alignment pattern in which the orientation of the optical axis rotates in at least one direction in the plane of the optically anisotropic layer 10C, and a portion having a constant orientation of the optical axis may also be provided.

[0146] Figure 4 and Figure 5 In the optically anisotropic layer 10C shown, the orientation of the optical axis 30A of the liquid crystal compound 30 in the liquid crystal alignment pattern of the optically anisotropic layer 10C continuously rotates only along the arrow X direction.

[0147] The present invention is not limited to this, and various structures can be used as long as the orientation of the optical axis 30A of the liquid crystal compound 30 in the optically anisotropic layer continuously rotates in one direction.

[0148] As an example, the optically anisotropic layer 10D is exemplified, in which, as Figure 6 conceptually shown in the top view of, the liquid crystal alignment pattern is a concentric circular pattern having a direction in which the orientation of the optical axis of the liquid crystal compound 30 continuously rotates while changing in a concentric circular shape from the inside to the outside. In other words, Figure 6 the liquid crystal alignment pattern of the optically anisotropic layer 10D shown is a liquid crystal alignment pattern in which a direction in which the orientation of the optical axis of the liquid crystal compound 30 continuously rotates while changing is radially provided from the center of the optically anisotropic layer 10D. Specifically, in the optically anisotropic layer 10D, the orientation of the optical axis 30A continuously rotates while changing in a plurality of directions from the center of the optically anisotropic layer 10D toward the outside, for example, the direction indicated by the arrow A1, the direction indicated by the arrow A2, the direction indicated by the arrow A3...

[0149] <Composition>

[0150] (Liquid crystal compound)

[0151] The optically anisotropic layer is formed using a composition containing a liquid crystal compound.

[0152] Liquid crystal compounds can generally be classified into rod-like types and disc-like types according to their shapes. Moreover, there are low-molecular types and high-molecular types respectively. A high polymer refers to a substance with a degree of polymerization of 100 or more usually (Physical Chemistry of Polymers / Phase Transition Kinetics, edited by Masao Doi, page 2, Iwanami Shoten, 1992). In the present invention, any liquid crystal compound can be used, but a rod-like liquid crystal compound or a disc-like liquid crystal compound is preferred. And a monomer or a liquid crystal compound with a lower molecular weight and a degree of polymerization less than 100 is preferred.

[0153] As the rod-like liquid crystal compound, for example, the compounds described in Claim 1 of Japanese Patent Application Laid-Open No. 11-513019 or paragraphs

[0026] to

[0098] of Japanese Patent Application Laid-Open No. 2005-289980 are preferred. As the disc-like liquid crystal compound, for example, the compounds described in paragraphs

[0020] to

[0067] of Japanese Patent Application Laid-Open No. 2007-108732 or paragraphs

[0013] to

[0108] of Japanese Patent Application Laid-Open No. 2010-244038 are preferred.

[0154] As the above liquid crystal compound, a liquid crystal compound with inverse wavelength dispersion can be used.

[0155] Among them, in the present specification, the "liquid crystal compound with inverse wavelength dispersion" means that when measuring the in-plane retardation (Re) value at a specific wavelength (visible light range) of a retardation film made using this compound, the Re value becomes equal or higher as the measurement wavelength becomes larger.

[0156] The liquid crystal compound preferably has a polymerizable group. That is, the liquid crystal compound is preferably a polymerizable liquid crystal compound. As the polymerizable group possessed by the liquid crystal compound, for example, radical polymerizable groups such as acryloyl group, methacryloyl group and vinyl group, and cationic polymerizable groups such as epoxy group can be cited.

[0157] By polymerizing such a polymerizable liquid crystal compound, the orientation of the liquid crystal compound can be fixed. In addition, after the liquid crystal compound is fixed by polymerization, it is no longer necessary to exhibit liquid crystallinity.

[0158] As the liquid crystal compound, a liquid crystal compound having both a cationic polymerizable group and a radical polymerizable group is preferred. If it is such a liquid crystal compound, as will be described later, an optically anisotropic layer can be effectively manufactured.

[0159] As the liquid crystal compound, a liquid crystal compound represented by the formula (I) (hereinafter, also referred to as "specific liquid crystal compound") is preferred.

[0160] [Chemical formula 1]

[0161]

[0162] In formula (I),

[0163] X 1 represents a hydrogen atom or a group represented by *-L 1 -P 1 . * represents the bonding position.

[0164] X 2 represents a hydrogen atom or a group represented by *-L 2 -P 2 . * represents the bonding position.

[0165] P 1 ~P 5 each independently represents a polymerizable group represented by any one of the following formulas (Ia) to (Ij). As the groups possessed by any one of P 1 ~P 5 , at least one represents a polymerizable group represented by any one of formulas (Ia) to (Ic), and at least one represents a polymerizable group represented by any one of formulas (Id) to (Ij).

[0166] L 1 ~L 5 each independently represents a single bond or an alkylene group having 1 to 20 carbon atoms. In the alkylene group having 1 to 20 carbon atoms, at least one -CH2- may be substituted with -O-, -S-, -NR X1 -, or -CO-, at least one -(CH2)2- may be substituted with -CH=CH- or -C≡C-, and at least one of the hydrogen atoms bonded to the carbon atom may be substituted with a fluorine atom or a chlorine atom. R X1 represents a hydrogen atom, an alkyl group having 1 to 15 carbon atoms, or a group represented by -(CH2) n -R X2 . In the alkyl group having 1 to 15 carbon atoms and the group represented by -(CH2) n -R X2 , at least one -CH2- may be substituted with -O-, -S-, -NR X3 -, or -CO-, at least one -(CH2)2- may be substituted with -CH=CH- or -C≡C-, and at least one of the hydrogen atoms bonded to the carbon atom may be substituted with a fluorine atom or a chlorine atom. R X2 represents a hydrogen atom or an alkyl group having 1 to 15 carbon atoms. R X3 represents a polymerizable group represented by any one of formulas (Ia) to (Ij). n represents an integer of 0 to 6.

[0167] A 1 ~A 3Each independently represents an aromatic ring group which may have a substituent or a non-aromatic ring group which may have a substituent.

[0168] Z 1 ~Z 4 Each independently represents -O-, -S-, -OCH2-, -CH2CH2-, -CO-, -COO-, -CO-S-, -O-CO-O-, -CO-NH-, -SCH2-, -CF2O-, -CF2S-, -CH=CH-COO-, -CH=CH-OCO-, -COO-CH2CH2-, -OCO-CH2CH2-, -COO-CH2-, -OCO-CH2-, -CH=CH-, -N=N-, -CH=N-N=CH-, -CH=N-, -CF=CF-, -C≡C-, -C≡C-C≡C-, -OCH2CH2O-, -SCH2CH2S- or a single bond.

[0169] a and b each independently represent an integer from 0 to 8, and 3 ≤ a + b ≤ 8. e to g each independently represent an integer from 0 to 3.

[0170] Among them, in formula (I), 3 ≤ c + d + E + f + G.

[0171] c represents 0 when X 1 is a hydrogen atom, and represents 1 when X 1 represents a group represented by *-L 1 -P 1 d represents 0 when X 2 is a hydrogen atom, and represents 1 when X 2 represents a group represented by *-L 2 -P 2 E represents 0 when a represents 0, represents the value of e when a represents 1, and represents the total value of multiple e's when a represents an integer from 2 to 8. G represents 0 when b represents 0, represents the value of g when b represents 1, and represents the total value of multiple g's when b represents an integer from 2 to 8.

[0172] When a represents an integer from 2 to 8, multiple Z's 1 with each other and multiple A's 1 -(L 3 -P 3 ) e with each other may be the same or different from each other. When e represents an integer of 2 or 3, multiple L's 3 with each other and multiple P's 3They may be the same as or different from each other. When b represents an integer of 2 to 8, there are multiple Zs 4 each other and there are multiple As 3 -(L 5 -P 5 ) g They may be the same as or different from each other. When g represents an integer of 2 or 3, there are multiple Ls 5 each other and there are multiple Ps 5 They may be the same as or different from each other. When f represents an integer of 2 or 3, there are multiple Ls 4 each other and there are multiple Ps 4 They may be the same as or different from each other.

[0173] In formula (I), X 1 each independently represents a hydrogen atom or a group represented by *-L 1 -P 1 X 2 each independently represents a hydrogen atom or a group represented by *-L 2 -P 2 * represents the bonding position.

[0174] L 1 、L 2 、P 1 and P 2 are as described later.

[0175] As X 1 it is preferably a group represented by *-L 1 -P 1

[0176] As X 2 it is preferably a group represented by *-L 2 -P 2

[0177] In formula (I), P 1 ~P 5 each independently represents a polymerizable group represented by any one of formula (Ia) to formula (Ij). As the polymerizable group in the liquid crystal compound represented by formula (I) for P 1 ~P 5 among the groups possessed by any one of them, at least one represents a polymerizable group represented by any one of formula (Ia) to formula (Ic) (hereinafter, also referred to as "polymerizable group E"), and at least one represents a polymerizable group represented by any one of formula (Id) to formula (Ij) (hereinafter, also referred to as "polymerizable group R").

[0178] That is, a specific liquid crystal compound as P 1 ​​~P 5 Among the groups possessed by any one of them, at least one represents a polymerizable group E and at least one represents a polymerizable group R. Specifically, when a is 0, b is 3, f and g are 1, and X 1 is a group represented by *-L 1 -P 1 denotes the group, X 2 is a group represented by *-L 2 -P 2 denotes the group, the specific liquid crystal compound does not have P 3 , so it represents as P 1 , P 2 , P 4 and P 5 Among the groups possessed by any one of them, at least one represents a polymerizable group E and at least one represents a polymerizable group R.

[0179] P 1 ~P 5 Among them, preferably at least two of P 1 ~P 5 represent a polymerizable group E, and at least two of P 1 ~P 5 represent a polymerizable group R.

[0180] And, as the polymerizable group E, from the aspect that the effects of the present invention are more excellent, a polymerizable group represented by the formula (Ia) is preferred. As the polymerizable group R, from the aspect that the effects of the present invention are more excellent, a polymerizable group represented by the formula (Id) is preferred.

[0181] [Chemical formula 2]

[0182]

[0183] In the formulas (Ia) to (Ij), the dashed line indicates the bonding position. R I1 represents a hydrogen atom or an alkyl group having 1 to 15 carbon atoms. In the alkyl group having 1 to 15 carbon atoms, at least one -CH2- can be replaced by -O-, -S-, -NR I2 -, or -CO-, at least one -(CH2)2- can be replaced by -CH=CH- or -C≡C-, and at least one of the hydrogen atoms bonded to the carbon atom can be replaced by a fluorine atom or a chlorine atom. R I2 represents a hydrogen atom or an alkyl group having 1 to 14 carbon atoms.

[0184] The bonding position indicated by the dashed line, for example, means the following bonding mode when P 1 is a group represented by the formula (Ia). *When a is 0, it represents bonding to Z 2The bonding position, when a is an integer from 1 to 8, represents the bonding position with Z 1 The bonding position.

[0185] [Chemical formula 3]

[0186]

[0187] The above-mentioned alkyl group represented by R I1 can be any of linear, branched and cyclic, preferably linear or branched, more preferably linear.

[0188] Moreover, in the above-mentioned alkyl group represented by R I1 when there is a structure in which at least one -CH2- is substituted by -O-, -S-, -NR I2 -, or -CO-, the number of carbon atoms of the alkyl group refers to the number of carbon atoms counted by the method shown below.

[0189] In the above-mentioned alkyl group represented by R I1 when there is a structure in which -CH2- is substituted by -O-, -S- or -CO-, the number of carbon atoms of the above-mentioned alkyl group refers to the number of carbon atoms counted by regarding the -O-, -S- or -CO- introduced in place of -CH2- as -CH2-. That is, for example, when R I1 is a group represented by -CH2-CO-O-C4H 10 the number of carbon atoms of this group is 7.

[0190] In the above-mentioned alkyl group represented by R I1 when there is a structure in which -CH2- is substituted by -NR I2 -, the number of carbon atoms of the above-mentioned alkyl group refers to the number of carbon atoms counted by regarding the -NR I2 - introduced in place of -CH2- as -CHR I2 -. That is, for example, when R I1 is a group represented by -CH2-CO-NH-C4H 10 the number of carbon atoms of this group is 7, and for example, when it is a group represented by -CH2-CO-N(CH3)-C4H 10 the number of carbon atoms of this group is 8.

[0191] Moreover, when R I1 represents an alkyl group having 1 to 15 carbon atoms in which at least one -CH2- is substituted by -O-, -S-, -NR I2 -, or -CO-, the total number of -O-, -S-, -NR I2 - and -CO- introduced in place of -CH2- in the above-mentioned alkyl group is preferably 1 to 4, more preferably 1 or 2.

[0192] Further, when R I1 represents an alkyl group having 1 to 15 carbon atoms in which at least one -CH2- is replaced by -O-, -S-, -NR I2 -, or -CO-, the positions at which -O-, -S-, -NR I2 -, or -CO- are introduced in place of -CH2- in the above alkyl group are not particularly limited. For example, they can be the positions adjacent to the carbon atoms constituting the epoxy group as shown in formula (Ia) and the positions adjacent to the carbon atoms constituting the oxetanyl group as shown in formula (Ic), or can be other positions.

[0193] Further, when R I1 represents an alkyl group having 1 to 15 carbon atoms in which at least one -CH2- is replaced by -O-, -S-, -NR I2 -, or -CO-, adjacent -CH2- in the above alkyl group can be respectively replaced by groups selected from -O-, -S-, -NR I2 -, and -CO-. That is, R I1 can be, for example, an alkyl group having 1 to 15 carbon atoms substituted with -CO-O- or the like.

[0194] Further, when R I1 represents an alkyl group having 1 to 15 carbon atoms in which at least one -(CH2)2- is replaced by -CH=CH- or -C≡C-, the total number of -CH=CH- and -C≡C- introduced in place of -(CH2)2- in the above alkyl group is preferably 1 to 4, more preferably 1 or 2.

[0195] Further, when R I1 represents an alkyl group having 1 to 15 carbon atoms in which at least one -(CH2)2- is replaced by -CH=CH- or -C≡C-, the positions at which -CH=CH- and -C≡C- are introduced in place of -(CH2)2- in the above alkyl group can be any of the positions adjacent to the carbon atoms constituting the epoxy group as shown in formula (Ia) and the positions adjacent to the carbon atoms constituting the oxetanyl group as shown in formula (Ic), or can be other positions.

[0196] Further, at least one of the hydrogen atoms bonded to the carbon atom in R I1 can be replaced by a fluorine atom or a chlorine atom. All of the hydrogen atoms bonded to the carbon atom can be replaced by a fluorine atom or a chlorine atom.

[0197] As R I2 , it is preferably a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and still more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.

[0198] As R I1 , it is preferably a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, still more preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and particularly preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.

[0199] In formula (I), L 1 ~L 5 each independently represents a single bond or an alkylene group having 1 to 20 carbon atoms. In the alkylene group having 1 to 20 carbon atoms, at least one -CH2- can be replaced by -O-, -S-, -NR X1 -, or -CO-, at least one -(CH2)2- can be replaced by -CH=CH- or -C≡C-, and at least one of the hydrogen atoms bonded to the carbon atom can be replaced by a fluorine atom or a chlorine atom.

[0200] The above-mentioned alkylene group represented by L 1 ~L 5 can be any of linear, branched, and cyclic, preferably linear or branched, and more preferably linear.

[0201] Moreover, the method for counting the number of carbon atoms in the above-mentioned alkylene group represented by L 1 ~L 5 is the same as the method for counting the number of carbon atoms in the above-mentioned alkyl group represented by the above R I1 .

[0202] For example, when the above-mentioned alkylene group is a group represented by -CH2-CO-O-CH2-, the number of carbon atoms in this group is 4. When the above-mentioned alkylene group is a group represented by -CO-NH-C4H8-, the number of carbon atoms in this group is 6. When the above-mentioned alkylene group is a group represented by -CO-N(CH3)-C4H8-, the number of carbon atoms in this group is 7. When the above-mentioned alkylene group is represented by -CO-N(CH2-C2H3O)-CH2-, the number of carbon atoms in this group is 7 (in addition, in the oxygen atom of the -C2H3O group, the -O- introduced in place of -CH2- is regarded as -CH2- when counting the number of carbon atoms).

[0203] Moreover, when L 1 ~L 5 represents an alkylene group having 1 to 20 carbon atoms in which at least one -CH2- is replaced by -O-, -S-, -NR X1 -, or -CO-, the total number of -O-, -S-, -NR X1 -, and -CO- introduced in place of -CH2- in the above-mentioned alkyl group is preferably 1 to 4, and more preferably 1 or 2.

[0204] And, in L 1 ~L 5 represents an alkylene group having 1 to 20 carbon atoms in which at least one -CH2- is replaced by -O-, -S-, -NR X1 -, or -CO-, the -O-, -S-, -NR X1 -, or -CO- introduced in place of -CH2- in the above alkylene group can be at a position adjacent to the polymerizable group represented by P 1 ~P 5 and at a position adjacent to the bonding position on the side different from the polymerizable group represented by P 1 ~P 5 represented, or can be at a position other than these.

[0205] And, in L 1 ~L 5 represents an alkylene group having 1 to 20 carbon atoms in which at least one -CH2- is replaced by -O-, -S-, -NR X1 -, or -CO-, adjacent -CH2- in the above alkylene group can be respectively replaced by a group selected from -O-, -S-, -NR X1 -, and -CO-. That is, L 1 ~L 5 can be, for example, an alkylene group having 1 to 20 carbon atoms substituted with -CO-O- or the like.

[0206] And, in L 1 ~L 5 represents an alkylene group having 1 to 20 carbon atoms in which at least one -(CH2)2- is replaced by -CH=CH- or -C≡C-, the total number of -CH=CH- and -C≡C- introduced in place of -(CH2)2- in the above alkylene group is preferably 1 to 4, more preferably 1 or 2.

[0207] And, in L 1 ~L 5 represents an alkylene group having 1 to 20 carbon atoms in which at least one -(CH2)2- is replaced by -CH=CH- or -C≡C-, the -CH=CH- and -C≡C- introduced in place of -(CH2)2- in the above alkylene group can be at a position adjacent to the polymerizable group represented by P 1 ~P 5 and at a position adjacent to the bonding position on the side different from the polymerizable group represented by P 1 ~P 5 represented, or can be at a position other than these.

[0208] And, L 1 ~L 5At least one of the hydrogen atoms bonded to the carbon atom may be substituted with a fluorine atom or a chlorine atom. All of the hydrogen atoms bonded to the carbon atom may be substituted with a fluorine atom or a chlorine atom.

[0209] As the alkyl group having 1 to 15 carbon atoms represented by R X1 It is preferably the alkyl group having 1 to 15 carbon atoms represented by the above R I1 It is preferably the alkyl group having 1 to 15 carbon atoms represented by the above R

[0210] As the - (CH2) X1 represented by R n -R X2 In the group represented by R X2 is preferably a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and still more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.

[0211] n represents an integer of 0 to 6, preferably an integer of 1 to 3, more preferably 1 or 2, and still more preferably 1.

[0212] And, regarding at least one -CH2- in the group represented by - (CH2) n -R X2 being substituted with -O-, -S-, -NR I2 - or -CO- and the way that at least one - (CH2)2- is substituted with -CH=CH- or -C≡C-, it is the same as the alkyl group having 1 to 15 carbon atoms represented by the above R I1 represented by

[0213] R X3 represents a polymerizable group represented by any one of the above formulas (Ia) to (Ij), preferably a polymerizable group represented by formula (Ia) or a polymerizable group represented by formula (Id).

[0214] As L 1 ~L 5 From the aspect that the effects of the present invention are more excellent, the above-mentioned alkylene group having 1 to 20 carbon atoms is preferred, and more preferably an alkylene group having 1 to 20 carbon atoms in which at least one -CH2- can be substituted with -O- and -CO-. And the hydrogen atom in the above alkylene group may be substituted with a fluorine atom.

[0215] And, as L 1 and L 2 is preferably an alkylene group having 1 to 20 carbon atoms.

[0216] As L 1 and L 2The upper limit of the number of carbon atoms of the above-mentioned alkylene group having 1 to 20 carbon atoms is preferably 12 or less, more preferably 10 or less, still more preferably 8 or less, particularly preferably 7 or less, and most preferably 6 or less, from the aspect of more excellent effects of the present invention and the aspect that the phase transition temperature (Iso) of the liquid crystal phase-isotropic phase of a specific liquid crystal compound becomes higher. As the lower limit, from the aspect of more excellent effects of the present invention and the aspect that the melting point of a specific liquid crystal compound becomes lower, it is preferably 2 or more, more preferably 3 or more.

[0217] As L 3 ~L 5 The upper limit of the number of carbon atoms of the above-mentioned alkylene group having 1 to 20 carbon atoms is preferably 12 or less, more preferably 10 or less, still more preferably 8 or less, particularly preferably 5 or less, and most preferably 4 or less, from the aspect of more excellent effects of the present invention and the aspect that the phase transition temperature (Iso) of the liquid crystal phase-isotropic phase of a specific liquid crystal compound becomes higher. As the lower limit, it is preferably 1 or more.

[0218] Among them, as L 3 and L 5 The number of carbon atoms of the above-mentioned alkylene group having 1 to 20 carbon atoms is preferably 1 to 5, more preferably 1 to 4, from the aspect of more excellent effects of the present invention, the aspect that the phase transition temperature (Iso) of the liquid crystal phase-isotropic phase of a specific liquid crystal compound becomes higher, and the aspect that the melting point of a specific liquid crystal compound becomes lower.

[0219] As L 1 ~L 5 , for example, -O-CH2-, -O-CH2CH2-, -O-CH2CH2CH2-, -O-CH2CH2CH2CH2-, -O-CH2CH2OCH2-, -O-CH2CH2CH2CH2CH2-, -O-CH2CH2CH2OCH2-, -O-CH2CH2CH2CH2CH2CH2-, -O-CH2CH2CH2CH2OCH2-, -COO-CH2-, -COO-CH2CH2-, -COO-CH2CH2CH2-, -COO-CH2CH2CH2CH2-, -OCO-CH2CH2OCH2- and -CONR X1 -CH2-. R X1 As described above.

[0220] In formula (I), A 1 ~A 3 each independently represents an aromatic ring group which may have a substituent or a non-aromatic ring group which may have a substituent.

[0221] Composed of A1 The above-mentioned aromatic ring group or the above-mentioned non-aromatic ring group represented by A is a (2 + e)-valent aromatic ring group which may have substituents or a (2 + e)-valent non-aromatic ring group which may have substituents. 2 The above-mentioned aromatic ring group or the above-mentioned non-aromatic ring group represented by A is a (2 + f)-valent aromatic ring group which may have substituents or a (2 + f)-valent non-aromatic ring group which may have substituents. 3 The above-mentioned aromatic ring group or the above-mentioned non-aromatic ring group represented by A is a (2 + g)-valent aromatic ring group which may have substituents or a (2 + g)-valent non-aromatic ring group which may have substituents. 1 The above-mentioned aromatic ring group or the above-mentioned non-aromatic ring group represented by A is, for example, a group formed by removing (2 + e) hydrogen atoms from the aromatic ring constituting the above-mentioned aromatic ring group or the non-aromatic ring constituting the above-mentioned non-aromatic ring group.

[0222] The aromatic ring constituting the above-mentioned aromatic ring group and the non-aromatic ring constituting the above-mentioned non-aromatic ring group are preferably 5- to 7-membered rings, more preferably 5-membered or 6-membered rings, and still more preferably 6-membered rings. The above-mentioned aromatic ring and the above-mentioned non-aromatic ring may be either a single ring or a polycyclic ring, and a single ring is preferred.

[0223] As the above-mentioned aromatic ring, it may be either an aromatic hydrocarbon ring or an aromatic heterocyclic ring. From the aspect that the liquid crystallinity of a specific liquid crystal compound is more excellent, an aromatic hydrocarbon ring is preferred.

[0224] As the aromatic hydrocarbon ring, a benzene ring and a naphthalene ring can be cited, and a benzene ring is preferred.

[0225] The heteroatom contained in the aromatic heterocyclic ring is not particularly limited. For example, a nitrogen atom can be cited. The number of heteroatoms contained in the aromatic heterocyclic ring is not particularly limited, and is preferably 1 to 4, more preferably 1 or 2.

[0226] As the aromatic heterocyclic ring, for example, a pyridine ring and a pyrimidine ring can be cited.

[0227] As the non-aromatic ring, it may be either an aliphatic hydrocarbon ring or an aliphatic heterocyclic ring. From the aspect that the liquid crystallinity of a specific liquid crystal compound is more excellent, an aliphatic hydrocarbon ring is preferred.

[0228] As the aliphatic hydrocarbon ring, for example, a cyclohexane ring can be cited.

[0229] The heteroatom contained in the aliphatic heterocyclic ring is not particularly limited. For example, a nitrogen atom can be cited. The number of heteroatoms contained in the aliphatic heterocyclic ring is not particularly limited, and is preferably 1 to 4, more preferably 1 or 2.

[0230] As the aliphatic heterocyclic ring, for example, a piperazine ring can be cited.

[0231] As A 1 ~A 3 , from the aspect of more excellent liquid crystallinity of a specific liquid crystal compound, an aromatic hydrocarbon ring group which may have a substituent or an aliphatic hydrocarbon ring group which may have a substituent is preferably used. The above-mentioned aromatic hydrocarbon ring group or the above-mentioned aliphatic hydrocarbon ring group represented by A 1 is, for example, a group formed by removing (2 + e) hydrogen atoms from an aromatic hydrocarbon ring constituting the above-mentioned aromatic hydrocarbon ring group or an aliphatic hydrocarbon ring constituting the above-mentioned aliphatic hydrocarbon ring group.

[0232] As A 1 ~A 3 , a phenylene group which may have a substituent or a cyclohexylene group which may have a substituent is preferred, and a 1,4-phenylene group which may have a substituent or a trans-1,4-cyclohexylene group which may have a substituent is more preferred.

[0233] When A 1 is a benzene ring group, the bonding positions of the benzene ring with Z 1 and Z 2 are preferably the 1,4-positions (para-positions). When A 2 is a benzene ring group, the bonding positions of the benzene ring with Z 2 and Z 3 are preferably the 1,4-positions (para-positions). When A 3 is a benzene ring group, the bonding positions of the benzene ring with Z 3 and Z 4 are preferably the 1,4-positions (para-positions).

[0234] When A 1 is a cyclohexane ring group, the bonding positions of the cyclohexane ring with Z 1 and Z 2 are preferably the trans-1,4-positions (trans-para-positions). When A 2 is a cyclohexane ring group, the bonding positions of the cyclohexane ring with Z 2 and Z 3 are preferably the trans-1,4-positions (trans-para-positions). When A 3 is a cyclohexane ring group, the bonding positions of the cyclohexane ring with Z 3 and Z 4 are preferably the trans-1,4-positions (trans-para-positions).

[0235] The substituents which the above-mentioned aromatic ring group and the above-mentioned non-aromatic ring group may have mean that, in formula (I), except for -L 3 -P 3 , -L 4 -P 4 and -L 5 -P 5Substituents other than these.

[0236] Examples of the above substituents include a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 5 carbon atoms that may be substituted by a halogen atom, an alkoxy group having 1 to 5 carbon atoms, an alkylthio group having 1 to 5 carbon atoms, an acyloxy group having 2 to 6 carbon atoms, an alkoxycarbonyl group having 2 to 6 carbon atoms, a carbamoyl group, an alkyl-substituted carbamoyl group having 2 to 6 carbon atoms, and an amide group having 2 to 6 carbon atoms.

[0237] In formula (I), Z 1 ~Z 4 each independently represents -O-, -S-, -OCH2-, -CH2CH2-, -CO-, -COO-, -CO-S-, -O-CO-O-, -CO-NH-, -SCH2-, -CF2O-, -CF2S-, -CH=CH-COO-, -CH=CH-OCO-, -COO-CH2CH2-, -OCO-CH2CH2-, -COO-CH2-, -OCO-CH2-, -CH=CH-, -N=N-, -CH=N-N=CH-, -CH=N-, -CF=CF-, -C≡C-, -C≡C-C≡C-, -OCH2CH2O-, -SCH2CH2S-, or a single bond.

[0238] As Z 1 ~Z 4 from the aspect that the liquid crystallinity of a specific liquid crystal compound is more excellent, it is preferably -OCH2-, -CH2CH2-, -COO-, -CO-S-, -CO-NH-, -CH=CH-COO-, -CH=CH-, -N=N-, -CH=N-N=CH-, -CH=N-, -C≡C-, or a single bond, more preferably -COO- or a single bond, and further preferably -COO-.

[0239] Preferably, at least two of Z 1 ~Z 4 represent -COO-, and more preferably, Z 1 and Z 4 represent a single bond and Z 2 and Z 3 represent -COO- (preferably, a carbonyl group is arranged on the bonding position side with respect to A 2 ).

[0240] In formula (I), a and b each independently represent an integer of 0 to 8 and 3 ≤ a + b ≤ 8. e to g each independently represent an integer of 0 to 3.

[0241] In terms of the more excellent effects of the present invention, a and b are each independently preferably an integer from 1 to 8, more preferably an integer from 1 to 6, still more preferably an integer from 1 to 5, particularly preferably an integer from 1 to 4, and most preferably an integer from 2 to 4.

[0242] Moreover, in terms of the more excellent effects of the present invention, a and b preferably satisfy 4 ≤ a + b ≤ 8, more preferably satisfy 4 ≤ a + b ≤ 6, and still more preferably satisfy a + b = 4.

[0243] e to g are each independently preferably an integer from 0 to 2, and more preferably 0 or 1.

[0244] f is preferably an integer from 0 to 3, more preferably an integer from 0 to 2, still more preferably 0 or 1, and particularly preferably 0.

[0245] Among them, in formula (I), 3 ≤ c + d + E + f + G.

[0246] "3 ≤ c + d + E + f + G" means that the total value of c, d, E, f, and G is 3 or more.

[0247] c represents 0 when X 1 is a hydrogen atom, and represents 1 when X 1 represents the group represented by *-L 1 -P 1 d represents 0 when X 2 is a hydrogen atom, and represents 1 when X 2 represents the group represented by *-L 2 -P 2 E represents 0 when a represents 0, represents the value of e when a represents 1, and represents the total value of multiple e's when a represents an integer from 2 to 8. G represents 0 when b represents 0, represents the value of g when b represents 1, and represents the total value of multiple g's when b represents an integer from 2 to 8.

[0248] Hereinafter, an example is given to illustrate E and G. When the specific liquid crystal compound is a compound represented by formula (IX), E corresponds to the value of one e explicitly shown in formula (IX). Moreover, when the specific liquid crystal compound is a compound represented by formula (IY), E corresponds to the total value of three e's explicitly shown in formula (IY). In addition, the definition of G is the same as that of E.

[0249] [Chemical formula 4]

[0250]

[0251] The upper limit value of c + d + E + f + G is preferably 14 or less, more preferably 10 or less, still more preferably 8 or less, and particularly preferably 6 or less. As the lower limit value, it is 3 or more, preferably 4 or more.

[0252] Among them, c + d + E + f + G preferably satisfies 3 ≤ c + d + E + f + G ≤ 10, more preferably satisfies 4 ≤ c + d + E + f + G ≤ 6, and still more preferably satisfies c + d + E + f + G = 4.

[0253] From the aspect of more excellent effects of the present invention, E and G are each independently preferably an integer of 1 to 4, more preferably an integer of 1 to 3, and still more preferably 1 or 2.

[0254] When a represents an integer of 2 to 8, there are multiple A 1 Among them, it is substituted with the A closest to the Z 2 side 1 in the group represented by (L 3 -P 3 ) e e is preferably an integer of 1 to 3, more preferably 1 or 2. In the above case, when substituted with other A 1 in the group represented by (L 3 -P 3 ) e e only needs to be an integer of 0 to 3, preferably 0 to 2, and more preferably 0 or 1.

[0255] When b represents an integer of 2 to 8, there are multiple A 3 Among them, it is substituted with the A closest to the Z 3 side 3 in the group represented by (L 5 -P 5 ) g g is preferably an integer of 1 to 3, more preferably 1 or 2. In the above case, when substituted with other A 3 in the group represented by (L 5 -P 5 ) g g only needs to be an integer of 0 to 3, preferably 0 to 2, and more preferably 0 or 1.

[0256] From the aspect of more excellent effects of the present invention, the specific liquid crystal compound is preferably a compound represented by formula (II).

[0257] [Chemical formula 5]

[0258]

[0259] Each of the symbols in formula (II) has the same meaning as each of the symbols in formula (I), and preferably the same preferred mode.

[0260] In terms of more excellent effects of the present invention, the specific liquid crystal compound is also preferably a compound represented by formula (III).

[0261] [Chemical formula 6]

[0262]

[0263] Each of the symbols other than a1, b1, e1, e2, g1 and g2 in formula (III) has the same meaning as each of the symbols in formula (I), and preferably the same preferred mode.

[0264] In formula (III), a1 and b1 each independently represent 0 or 1 and 1 ≤ a1 + b1 ≤ 2. e1 and g1 each independently represent an integer from 1 to 3. e2 and g2 each independently represent an integer from 0 to 2. e1 + e2 represents an integer from 0 to 3, and g1 + g2 represents an integer from 0 to 3.

[0265] a1 and b1 preferably satisfy a1 + b1 = 2.

[0266] e1 and g1 each independently are preferably 1 or 2, more preferably 1.

[0267] e2 and g2 each independently are preferably 0 or 1.

[0268] e1 + e2 and g1 + g2 are preferably 1 or 2, more preferably 1.

[0269] Among them, in formula (III), 3 ≤ c + d + e1 + e2 + f + g1 + g2.

[0270] "3 ≤ c + d + e1 + e2 + f + g1 + g2" means that the total value of c, d, e1, e2, f, g1 and g2 is 3 or more.

[0271] c + d + e1 + e2 + f + g1 + g2 preferably satisfies 3 ≤ c + d + e1 + e2 + f + g1 + g2 ≤ 10, more preferably satisfies 4 ≤ c + d + e1 + e2 + f + g1 + g2 ≤ 6, and further preferably satisfies c + d + e1 + e2 + f + g1 + g2 = 4.

[0272] When a1 represents 1, there are multiple Zs 1 each other and there are multiple As 1 each other can be the same or different from each other.

[0273] When e1 represents 2 or 3 or e2 represents 1 or 2, there are multiple Ls 3 each other and there are multiple Ps3 They may be the same as or different from each other.

[0274] When b1 represents 1, there are multiple Zs 4 Each other and there are multiple As 3 They may be the same as or different from each other.

[0275] When g1 represents 2 or 3, or when g2 represents 1 or 2, there are multiple Ls 5 Each other and there are multiple Ps 5 They may be the same as or different from each other.

[0276] As the upper limit value of the melting point of a specific liquid crystal compound, from the aspect of suppressing the deterioration of smoothness and orientation caused by precipitation during the coating of the liquid crystal layer, it is preferably 200 °C or lower, more preferably 140 °C or lower, and further preferably 100 °C or lower. As the lower limit value, there is no particular limitation, and it is preferably 50 °C or higher. In addition, the melting point of a specific liquid crystal compound can be measured by observing while heating the specific compound under a polarized light microscope.

[0277] As the lower limit value of the phase transition temperature of the liquid crystal phase - isotropic phase (Iso) of a specific liquid crystal compound, it is preferably 180 °C or higher, more preferably 200 °C or higher, and further preferably 220 °C or higher. As the upper limit value, there is no particular limitation, and it is preferably 1000 °C or lower. In addition, the phase transition temperature of the liquid crystal phase - isotropic phase (Iso) of a specific liquid crystal compound can be measured by observing while heating the specific compound under a polarized light microscope.

[0278] As the lower limit value of the molecular weight of a specific liquid crystal compound, it is preferably 600 or higher, more preferably 800 or higher, and further preferably 900 or higher. In addition, as the upper limit value, it is preferably 2000 or lower, more preferably 1500 or lower, and further preferably 1200 or lower.

[0279] As the lower limit value of the total content of epoxy groups and oxetanyl groups (the total number of moles of epoxy groups and oxetanyl groups contained in every 1 g of a specific liquid crystal compound), it is preferably 2.00 mmol / g or higher, more preferably 3.00 mmol / g or higher. As the upper limit value, it is preferably 25.00 mmol / g or lower, more preferably 15.00 mmol / g or lower, and further preferably 10.00 mmol / g or lower.

[0280] As the above epoxy groups and the above oxetanyl groups, for example, the above substituent E can be cited.

[0281] In the composition, the content of the liquid crystal compound is preferably 60 to 100% by mass, more preferably 70 to 95% by mass, and further preferably 80 to 90% by mass, based on the mass of the total solid content of the composition.

[0282] (Other components)

[0283] The composition may contain other components in addition to the liquid crystal compound.

[0284] [Curing agent]

[0285] The composition may contain a curing agent. In particular, when the above liquid crystal compound has a cationic polymerizable group, a compound having a reactive group capable of undergoing a polymerization reaction with the cationic polymerizable group is preferably used as the curing agent.

[0286] Examples of the curing agent include phenolic curing agents, amide curing agents, active ester curing agents, amine curing agents, carboxylic acid curing agents, acid anhydride curing agents, polythiourethane curing agents, isocyanate curing agents, blocked isocyanate curing agents, and carbodiimide compounds described in paragraphs

[0095] to

[0098] of Japanese Unexamined Patent Application Publication No. 2022-125980.

[0287] The curing agent preferably has a reactive group. The reactive group is not particularly limited, and a reactive group selected from phenolic hydroxyl groups, amino groups, and carboxyl groups is preferred, and a phenolic hydroxyl group is more preferred.

[0288] In the curing agent, the number of reactive groups is not particularly limited, but from the aspect of more excellent effects of the present invention, the lower limit is preferably 2 or more, more preferably 3 or more. The upper limit is preferably 20 or less, more preferably 12 or less, further preferably 10 or less, and particularly preferably 6 or less.

[0289] The lower limit of the content of the reactive group in the curing agent (the amount of substance of the reactive group contained in 1 g of the curing agent) is not particularly limited, but from the aspect of more excellent effects of the present invention, it is preferably 10 mmol / g or more, more preferably 15 mmol / g or more, and further preferably 20 mmol / g or more. The upper limit is preferably 50 mmol / g or less, more preferably 40 mmol / g or less.

[0290] The lower limit of the molecular weight of the curing agent is preferably 80 or more, more preferably 100 or more. The upper limit is preferably 1000 or less, more preferably 500 or less.

[0291] From the aspect of more excellent effects of the present invention, the curing agent preferably contains a compound having a phenolic hydroxyl group (hereinafter, also referred to as "phenolic compound"), a compound having an amino group or a compound having a carboxyl group, and more preferably contains a phenolic compound.

[0292] As the phenolic compound, a phenolic compound having 2 or more functional groups (a compound having 2 or more phenolic hydroxyl groups) is preferred, and a phenolic compound having 2 to 6 functional groups (a compound having 2 to 6 phenolic hydroxyl groups) is more preferred.

[0293] As the lower limit value of the hydroxyl value of the phenolic compound, it is preferably 20 g / mol or more, and more preferably 25 g / mol or more. As the upper limit value, from the aspect of not affecting the liquid crystallinity and being able to impart sufficient curability, it is preferably 100 g / mol or less, more preferably 67 g / mol or less, and further preferably 50 g / mol or less.

[0294] As the phenolic compound, there is no particular limitation, and known compounds used as phenolic curing agents can be appropriately used. Among them, from the aspect of more excellent effects of the present invention, as the phenolic compound, catechol, resorcinol, pyrogallol, pyrogallol carboxylic acid or a compound represented by the following formula (P1) is preferred.

[0295] [Chemical formula 7]

[0296]

[0297] In formula (P1), ma represents an integer of 0 or more.

[0298] ma is preferably 0 to 10, more preferably 0 to 3, further preferably 0 or 1, and particularly preferably 1.

[0299] In formula (P1), na and nc each independently represent an integer of 1 or more.

[0300] na and nc are preferably 1 to 4, more preferably 2 to 4, further preferably 2 to 3, and particularly preferably 2.

[0301] In formula (P1), nb represents an integer of 0 to 3.

[0302] nb is preferably 0 or 1.

[0303] In formula (P1), when there are multiple Rs 2 the multiple Rs 2 can be the same or different from each other. When there are multiple Rs 3 the multiple Rs 3 can be the same or different from each other. When there are multiple Ls x2 the multiple Ls x2They can be the same or different respectively. In the case where there are multiple nbs, the multiple nbs can be the same or different respectively.

[0304] In formula (P1), R 1 and R 4 each independently represents a hydrogen atom or a substituent.

[0305] As the substituent represented by R 1 and R 4 for example, a halogen atom, a carboxyl group, an amino group, an alkyl group, an alkoxy group, and an alkoxycarbonyl group can be cited.

[0306] The above alkyl group can be either linear or branched. As the number of carbon atoms of the above alkyl group, it is preferably 1 to 10, more preferably 1 to 6, further preferably 1 to 3, and particularly preferably 1. And the above alkyl group can also have a substituent.

[0307] The alkyl part in the above alkoxy group and the alkyl part in the above alkoxycarbonyl group are the same as the above alkyl group.

[0308] As R 1 and R 4 , it is preferably a hydrogen atom or a halogen atom, more preferably a hydrogen atom or a chlorine atom, and further preferably a hydrogen atom.

[0309] In formula (P1), R 2 represents a hydrogen atom or a hydroxyl group.

[0310] In the case where there are multiple Rs 2 , it is preferred that at least one R 2 among the multiple Rs 2 represents a hydroxyl group, and more preferably all Rs 2 represent a hydroxyl group.

[0311] In formula (P1), Ar 1 and Ar 2 each independently represents a phenyl group or a naphthyl group.

[0312] As Ar 1 and Ar 2 , it is preferably a phenyl group.

[0313] In formula (P1), L x1 represents a single bond, -C(R 5 )(R 6 )-, -CO-, -SO2- or =N-N=. L x2 represents -C(R 7 )(R 8 )- or -CO-.

[0314] As L x1 , preferably -C(R5 )(R 6 )- or -CO-.

[0315] As L x2 , preferably -C(R 7 )(R 8 )-.

[0316] R 5 and R 8 each independently represent a hydrogen atom or a substituent.

[0317] As the above-mentioned substituent, it is preferably a hydroxyl group, a halogen atom, a carboxylic acid group, an alkyl group, an alkoxy group or an alkoxycarbonyl group, more preferably a hydroxyl group, a halogen atom, a carboxylic acid group, an alkyl group, an alkoxy group or an alkoxycarbonyl group.

[0318] The above-mentioned alkyl group can be either straight-chain or branched-chain. As the number of carbon atoms of the above-mentioned alkyl group, it is preferably 1 to 10, more preferably 1 to 6, further preferably 1 to 3, and particularly preferably 1. And, the above-mentioned alkyl group can have a substituent. As the substituent, for example, a halogen atom (such as a fluorine atom, etc.) can be cited.

[0319] The alkyl part in the above-mentioned alkoxy group and the alkyl part in the above-mentioned alkoxycarbonyl group are the same as the above-mentioned alkyl group.

[0320] As R 5 ~R 8 , it is preferably a hydrogen atom or a hydroxyl group, more preferably a hydrogen atom.

[0321] As L x1 , it is preferably -CH2-, -CH(OH)-, -C(CH3)2-, -C(CF3)2-, -CO-, -SO2- or =N-N=.

[0322] As L x2 , it is preferably -CH2-, -CH(OH)- or -CO-, more preferably -CH2-.

[0323] Among them, when ma represents 0, as L x1 , it is preferably -CH2-, -CH(OH)- or -CO-. When ma represents 1, as L x1 and L x2 , it is preferably -CH2-.

[0324] In formula (P1), when there are multiple R 5 , the multiple R 5 can be the same or different from each other. When there are multiple R 6 , the multiple R 6 can be the same or different from each other. R 7When there are multiple, there are multiple Rs 7 They can be the same or different respectively. R 8 When there are multiple, there are multiple Rs 8 They can be the same or different respectively.

[0325] In formula (P1), R 3 represents a substituent.

[0326] As the substituent represented by R 3 for example, an alkyl group, a phenyl group, a halogen atom, a carboxylic acid group, an alkoxy group, and an alkoxycarbonyl group can be cited.

[0327] The above alkyl group can be either linear or branched. As the number of carbon atoms of the above alkyl group, it is preferably 1 to 10, more preferably 1 to 6, still more preferably 1 to 3, and particularly preferably 1. Further, the above alkyl group can also have a substituent.

[0328] The alkyl part in the above alkoxy group and the alkyl part in the above alkoxycarbonyl group are the same as the above alkyl group.

[0329] The above phenyl group can also have a substituent.

[0330] As the compound represented by formula (P1), for example, the following compounds can be cited.

[0331] [Chemical formula 8]

[0332]

[0333] When the composition contains a curing agent, the content of the curing agent is preferably 0.1 to 40% by mass, more preferably 5 to 30% by mass, still more preferably 10 to 20% by mass, relative to the mass of the total solid content of the composition.

[0334] [Curing accelerator (curing catalyst)]

[0335] The composition can also contain a curing accelerator.

[0336] The type of the curing accelerator is not limited. For example, triphenylphosphine, an imidazole-based catalyst, a boron trifluoride amine complex, a tertiary amine, an organic phosphine, a phosphonium salt, a tetraphenylborate salt, an organic acid dihydrazide, a boron halide amine complex, the compounds described in paragraph

[0052] of Japanese Patent Laid-Open No. 2012-067225, and the compounds described in paragraphs

[0049] to

[0054] of Japanese Patent Laid-Open No. 2022-125980 can be cited.

[0337] When the composition contains a curing accelerator, the content of the curing accelerator is preferably 0.5 to 30% by mass, more preferably 1 to 20% by mass, and still more preferably 2 to 15% by mass with respect to the mass of the total solid components of the composition.

[0338] [Ultraviolet absorber]

[0339] The composition may contain an ultraviolet absorber. As described later, by including an ultraviolet absorber in the composition, an optically anisotropic layer can be effectively produced.

[0340] Examples of the ultraviolet absorber include compounds selected from the group consisting of merocyanine compounds (in particular, diethylamino-phenylsulfonyl-based ultraviolet absorbers), benzophenone compounds, benzoxazinone compounds, anthracene compounds, benzotriazole compounds, indole compounds, methylene compounds, benzodithiol compounds, and hydroxyphenyltriazine compounds.

[0341] The wavelength region of the ultraviolet rays absorbed by the ultraviolet absorber is not particularly limited, and an ultraviolet absorber having a maximum absorption wavelength in the wavelength region of 300 to 400 nm is preferably used.

[0342] When the composition contains an ultraviolet absorber, the content of the ultraviolet absorber is preferably 0.1 to 30% by mass, more preferably 1 to 20% by mass with respect to the mass of the total solid components of the composition.

[0343] [Chiral agent]

[0344] The composition may contain a chiral agent.

[0345] When the composition contains a chiral agent, the liquid crystal compound can be twisted and oriented along the helical axis. This orientation state is also referred to as a cholesteric orientation.

[0346] The type of the chiral agent is not particularly limited. Any of the known chiral agents (for example, those described in "Liquid Crystal Device Handbook", edited by the 142nd Committee of the Japan Society for the Promotion of Science, Chapter 3, Section 4-3, Chiral Agents for TN and STN, page 199, 1989) can also be used.

[0347] When the composition contains a chiral agent, the content of the chiral agent is preferably 0.01 to 5.0% by mass, more preferably 0.02 to 3.0% by mass, and still more preferably 0.05 to 2.0% by mass with respect to the total mass of the liquid crystal compound.

[0348] [Polymerization initiator]

[0349] The composition may also contain a polymerization initiator.

[0350] Examples of the polymerization reaction initiated by the polymerization initiator include a thermal polymerization reaction using a thermal polymerization initiator or a photopolymerization reaction using a photopolymerization initiator, and a photopolymerization reaction is more preferred. Among them, a radical polymerization initiator is preferably used.

[0351] When the composition contains a polymerization initiator, the content of the polymerization initiator is preferably 0.01 to 20% by mass, more preferably 0.4 to 8% by mass, based on the total mass of the solid components of the composition.

[0352] [Solvent]

[0353] The composition may contain a solvent.

[0354] The type of the solvent is not particularly limited, and an organic solvent is preferred. Examples of the organic solvent include cyclopentanone, cyclohexanone, ethyl acetate, methyl ethyl ketone, dichloromethane, and tetrahydrofuran.

[0355] When the composition contains a solvent, the content of the solvent is preferably an amount that makes the solid component concentration of the composition 1 to 90% by mass, more preferably 2 to 85% by mass.

[0356] The composition may contain other components other than the above components.

[0357] Examples of the other components include polyfunctional monomers, alignment control agents (vertical alignment agents, horizontal alignment agents), surfactants, adhesion improvers, plasticizers, polymerization inhibitors, antioxidants, light stabilizers, colorants, and metal oxide fine particles.

[0358] <Manufacturing method of the optically anisotropic layer>

[0359] The manufacturing method of the optically anisotropic layer of the present invention is not particularly limited.

[0360] Among them, from the aspect of being able to effectively manufacture the optically anisotropic layer, a manufacturing method having steps 1 to 3 is preferred.

[0361] Step 1: A step of forming a coating film using a composition containing a liquid crystal compound having a polymerizable group and aligning the liquid crystal compound in the formed coating film

[0362] Step 2: A step of polymerizing the liquid crystal compound to form a region where the polymerization rate of the liquid crystal compound continuously changes in the thickness direction of the coating film

[0363] Step 3: A step of performing a heat treatment on the coating film obtained in Step 2 to form a region where the birefringence Δn continuously changes in the thickness direction and the wavelength dispersion is constant

[0364] Hereinafter, the above-described steps 1 to 3 will be described in detail.

[0365] (Step 1)

[0366] Step 1 is a step of forming a coating film using a composition containing a liquid crystal compound having a polymerizable group and aligning the liquid crystal compound in the formed coating film. By carrying out this step, a coating film containing the aligned liquid crystal compound is formed.

[0367] As one of the preferred embodiments of this step, it is preferred to coat the composition on the alignment film of a support with an alignment film having a support and an alignment film to form a coating film and align the liquid crystal compound in the coating film. By carrying out this preferred embodiment, as Figure 7 shown, a laminate including a support 20, an alignment film 22, and a coating film 24 is formed.

[0368] Hereinafter, the steps of this preferred embodiment will be described in detail. First, the support and the alignment film used in this step will be described in detail.

[0369] The support is a member that supports the alignment film and the optically anisotropic layer.

[0370] As long as it can support the alignment film and the optically anisotropic layer, the support can use various sheet-like materials (films, plates).

[0371] In addition, the transmittance of the support is not particularly limited. For example, the transmittance of the support with respect to light having a wavelength of 550 nm is preferably 50% or more, more preferably 70% or more, and further preferably 85% or more.

[0372] The thickness of the support is preferably 1 to 1000 μm, more preferably 3 to 250 μm, and further preferably 5 to 150 μm.

[0373] The support can be a single layer or a multilayer.

[0374] As the support in the case of a single layer, examples thereof include supports made of glass, triacetyl cellulose, polyethylene terephthalate, polycarbonate, polyvinyl chloride, poly(meth)acrylate, and polyolefin. As an example of the support in the case of a multilayer, a support can be exemplified that includes any one of the supports of the aforementioned single layer as a substrate and has other layers provided on the surface of the substrate.

[0375] The alignment film can be formed by methods such as rubbing treatment of an organic compound (preferably a polymer), oblique evaporation of an inorganic compound, formation of a layer having microgrooves, or accumulation of an organic compound (for example, ω-tricosanoic acid, dioctadecylmethylammonium chloride, methyl stearate) based on the Langmuir-Blodgett method (LB film).

[0376] As the alignment film, a photo-alignment film can also be mentioned.

[0377] As the photo-alignment material used in the photo-alignment film, an azo compound, a photocrosslinkable polyimide, a photocrosslinkable polyamide, a photocrosslinkable polyester, a cinnamate compound, and a chalcone compound are preferably used.

[0378] The method for forming the photo-alignment film is not particularly limited, and examples thereof include the following method: after coating a photo-alignment film-forming composition containing a specified photo-alignment material on the surface of a support and drying it, the obtained coating film (photo-alignment film precursor) is exposed to form an alignment pattern.

[0379] In the case of forming an optically anisotropic layer having the above-described liquid crystal alignment pattern, a photo-alignment film formed by using an exposure apparatus for forming an alignment pattern can be used.

[0380] In Figure 8 a conceptual example of an exposure apparatus for forming an alignment pattern is shown.

[0381] Figure 8 The exposure apparatus 60 shown includes: a light source 64 equipped with a laser 62; a λ / 2 plate 65 that changes the polarization direction of the laser beam M emitted from the laser 62; a beam splitter 68 that separates the laser beam M emitted from the laser 62 into two light beams MA and MB; mirrors 70A and 70B respectively disposed on the optical paths of the two separated light beams MA and MB; and λ / 4 plates 72A and 72B.

[0382] In addition, although not shown in the figure, the light source 64 emits linearly polarized light P0. The λ / 4 plate 72A converts the linearly polarized light P0 (light beam MA) into right-handed circularly polarized light P R and the λ / 4 plate 72B converts the linearly polarized light P0 (light beam MB) into left-handed circularly polarized light P L .

[0383] The support 40 having the coating film 42 before forming the alignment pattern is disposed in the exposure unit, and the two light beams MA and light beam MB are made to cross on the coating film 42 and interfere with each other, and the interference light is irradiated onto the coating film 42 for exposure.

[0384] By the interference at this time, the polarization state of the light irradiated onto the coating film 42 changes periodically in an interference fringe pattern. Thus, a photo-alignment film having an alignment pattern in which the alignment state changes periodically can be obtained.

[0385] In the exposure apparatus 60, the period of the alignment pattern can be adjusted by changing the crossing angle α between the two light beams MA and MB. That is, in the exposure apparatus 60, by adjusting the crossing angle α, in the alignment pattern in which the orientation of the optical axis derived from the liquid crystal compound continuously rotates in one direction, the length of one period (one period Λ) in which the orientation of the optical axis rotates 180° in one direction in which the orientation of the optical axis rotates can be adjusted.

[0386] By forming an optically anisotropic layer on the photo-alignment film having an alignment pattern in which such an alignment state periodically changes, an optically anisotropic layer having a liquid crystal alignment pattern in which the orientation of the optical axis derived from the liquid crystal compound continuously rotates in one direction can be formed.

[0387] Moreover, the rotation direction of the optical axis can be reversed by rotating the optical axes of the λ / 4 plates 72A and 72B by 90° respectively.

[0388] The thickness of the alignment film is not particularly limited as long as it can exhibit an alignment function, and is preferably 0.01 to 5.0 μm, more preferably 0.05 to 3.0 μm, and further preferably 0.5 to 1.0 μm.

[0389] The composition containing the liquid crystal compound having a polymerizable group used in this step is as described above.

[0390] In addition, as the liquid crystal compound used in this step, a liquid crystal compound having a radical polymerizable group and a cationic polymerizable group is preferably used for the reasons described later.

[0391] Coating of the composition can be carried out by using various known methods used in coating of liquids such as bar coating, gravure coating, and spraying.

[0392] Next, an alignment treatment is performed on the coating film formed by coating to align the liquid crystal compound. By performing the alignment treatment, the liquid crystal compound in the coating film is aligned in a predetermined alignment state according to the alignment pattern of the alignment film.

[0393] As the alignment treatment, heat treatment is preferably used. The conditions for heating are not particularly limited, and the heating temperature is preferably 50 to 140 °C, and the heating time is preferably 0.5 to 20 minutes.

[0394] (Step 2)

[0395] Step 2 is a step of polymerizing the liquid crystal compound to form a region in which the polymerization rate of the liquid crystal compound continuously changes in the thickness direction of the coating film. By performing this step, regions having different degrees of curing of the liquid crystal compound are formed in the thickness direction of the coating film.

[0396] The steps of this process are not particularly limited, and examples thereof include a method of forming a coating film using a composition containing an ultraviolet absorber and exposing the formed coating film.

[0397] Hereinafter, as an example, use Figure 7 will be described. When a coating film is formed using a composition containing an ultraviolet absorber, the ultraviolet absorber is dispersed and present in the coating film in the thickness direction. For such a coating film, for example, if exposure is performed from the direction indicated by the hollow arrow of Figure 7 , in the first region 26 on the alignment film 22 side in the coating film 24, since the exposure energy is strong, the polymerization of the liquid crystal compound proceeds sufficiently. On the other hand, due to the influence of the ultraviolet absorber in the coating film 24, the exposure energy gradually decreases toward the depth direction. Therefore, in the second region 28 on the side opposite to the alignment film 22 side in the coating film 24, energy sufficient to cause sufficient polymerization of the liquid crystal compound is not irradiated. As a result, in the second region 28, the polymerization rate of the liquid crystal compound continuously decreases in the direction from the alignment film 22 side toward the side opposite to the alignment film 22 side.

[0398] In the above, a method in which the polymerization rate of the liquid crystal compound in the thickness direction of the coating film is changed by gradually decreasing the exposure energy in the depth direction of the coating film by using an ultraviolet absorber has been described in detail, but step 2 can also be implemented by other methods.

[0399] Furthermore, in order to form a region where the polymerization rate of the liquid crystal compound continuously changes as described above, it is preferable to use a liquid crystal compound having a radical polymerizable group and a cationic polymerizable group. By using such a liquid crystal compound, the radical polymerizable group can be polymerized in step 2 to form the above-mentioned region, and the cationic polymerizable group can be polymerized in step 3 described later.

[0400] In addition, regarding the judgment as to whether a region where the polymerization rate of the liquid crystal compound continuously changes is formed in the thickness direction of the coating film, for example, it can be judged as follows: the coating film is cut along the thickness direction, the cross section of the exposed coating film is analyzed by infrared absorption spectrometry or the like, and the residual rate of the polymerizable group in the thickness direction of the coating film is calculated.

[0401] In the method of forming a coating film using the composition containing the above-mentioned ultraviolet absorber and exposing the formed coating film, as the exposure treatment, ultraviolet irradiation treatment is preferable.

[0402] The conditions of the ultraviolet irradiation treatment are appropriately selected according to the coating film used, and the optimal conditions are selected. As the irradiation amount, it is preferably 0.1 to 1000 mJ / cm 2 , more preferably 1 to 300 mJ / cm 2 .

[0403] The ultraviolet irradiation treatment is preferably carried out in an atmosphere with a low oxygen concentration. The ultraviolet irradiation treatment is preferably carried out in a nitrogen atmosphere.

[0404] (Step 3)

[0405] Step 3 is a step of performing a heat treatment on the coating film obtained in Step 2 to form a region where the birefringence Δn continuously changes in the thickness direction and the wavelength dispersion is constant. By performing this step, the above-mentioned specific region is formed.

[0406] In the coating film obtained in Step 2, there is a region where the polymerization rate of the liquid crystal compound continuously changes in the thickness direction of the coating film. If a coating film including such a region is heat-treated, the orientation state of the liquid crystal compound remains unchanged in the region where the polymerization rate of the liquid crystal compound is high. On the other hand, in the region where the polymerization rate of the liquid crystal compound is low, the orientation state of the liquid crystal compound cannot be maintained by the heat treatment, resulting in orientation disorder of the liquid crystal compound. If such orientation disorder of the liquid crystal compound occurs, the birefringence Δn in this region decreases. That is, by performing this step, the region where the polymerization rate of the liquid crystal compound is high becomes a region with a high birefringence Δn, and the region where the polymerization rate of the liquid crystal compound is low becomes a region with a low birefringence Δn.

[0407] In particular, when a liquid crystal compound having a radical polymerizable group and a cationic polymerizable group is used as the liquid crystal compound, it is easy to form the above-mentioned specific region. As described above, when the liquid crystal compound having a radical polymerizable group and a cationic polymerizable group is used in Step 2, the cationic polymerizable group can be left in the coating film. If a heat treatment is performed on the coating film in which the cationic polymerizable group remains, the polymerization of the cationic polymerizable group proceeds, and the phase transition temperature of the liquid crystal phase-isotropic phase (Iso) gradually decreases, and the birefringence Δn also gradually decreases. Therefore, by selecting a specified heating temperature and time, it is easy to form a region where the birefringence Δn continuously changes.

[0408] In contrast, if a heat treatment is performed on a coating film in which no cationic polymerizable group remains, the birefringence Δn easily changes rapidly due to the heat treatment, making it difficult to form a specified specific region.

[0409] Moreover, in these Steps 1 to 3, since a specific region can be formed by using only a specified liquid crystal compound, the wavelength dispersion becomes constant in the specific region.

[0410] The conditions for the heat treatment implemented in this process are not particularly limited, and the optimal conditions are selected according to the coating film used. As the heating temperature during the heat treatment, it is preferably 50 to 300°C, and more preferably 100 to 200°C. As the heating time for the heating temperature, it is preferably 0.5 to 30 minutes, and more preferably 1 to 5 minutes. In addition, from the perspective of being able to significantly change the Δn of the liquid crystal compound, the heating temperature is preferably above the phase transition temperature of the liquid crystal phase-isotropic phase (Iso) of the liquid crystal compound.

[0411] After step 3, step 4 may be performed to expose the optically anisotropic layer obtained in step 3. Exposure can polymerize unreacted polymerizable groups. In particular, when using a liquid crystal compound having both radical polymerizable groups and cation polymerizable groups, step 4 can polymerize unreacted radical polymerizable groups in step 2.

[0412] As the exposure treatment, ultraviolet irradiation treatment is preferable.

[0413] The conditions for ultraviolet irradiation treatment are appropriately selected according to the coating film used, and the irradiation dose is preferably 50 to 2000 mJ / cm 2 , more preferably 100 to 1500 mJ / cm 2 .

[0414] The ultraviolet irradiation treatment is preferably performed in an atmosphere with a low oxygen concentration. The ultraviolet irradiation treatment is preferably performed in a nitrogen atmosphere.

[0415] <Application>

[0416] The optically anisotropic layer of the present invention can be applied to various applications. For example, by adjusting the in-plane retardation of the optically anisotropic layer, it can be used as a so-called λ / 4 plate or a λ / 2 plate.

[0417] A λ / 4 plate is a plate that converts linearly polarized light of a specific wavelength into circularly polarized light (or vice versa). More specifically, it is a plate whose in-plane retardation Re at a predetermined wavelength of λ nm is λ / 4 (or an odd multiple thereof).

[0418] The in-plane retardation (Re(550)) of the λ / 4 plate at a wavelength of 550nm can have an error of about 25nm centered around the ideal value (137.5nm), for example, preferably 110 to 160nm, more preferably 120 to 150nm.

[0419] Further, the λ / 2 plate is an optically anisotropic film in which the in-plane retardation Re(λ) at a specific wavelength λ nm satisfies Re(λ)≈λ / 2. This equation can be achieved at any wavelength (e.g., 550 nm) in the visible light region. Among them, the in-plane retardation Re(550) at a wavelength of 550 nm preferably satisfies the following relationship.

[0420] 210 nm ≤ Re(550) ≤ 300 nm

[0421] Further, when the optically anisotropic layer has the above-mentioned liquid crystal alignment pattern, it can also be used as a liquid crystal diffraction element.

[0422] Examples

[0423] Hereinafter, the present invention will be described in further detail based on examples. Materials, amounts used, ratios, processing contents, processing steps, etc. shown in the following examples can be appropriately changed as long as they do not depart from the gist of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the examples shown below.

[0424] <Synthesis of Polymerizable Liquid Crystal Compound LC1>

[0425] The following shows the synthesis route of the polymerizable liquid crystal compound LC1.

[0426] [Chemical formula 9]

[0427]

[0428] (Synthesis of Compound LC1A)

[0429] In N,N-dimethylacetamide (250 mL), gentisic acid (50.0 g), allyl bromide (43.2 g) and potassium bicarbonate (39.0 g) were stirred at 60 °C for 3 hours. 1N hydrochloric acid water and ethyl acetate were added to remove the aqueous phase, and then washed successively with 1N hydrochloric acid water, sodium bicarbonate water and brine. The organic layer was dried over magnesium sulfate, and after filtering magnesium sulfate, the solvent was removed by distillation under reduced pressure to obtain compound LC1A (60.3 g).

[0430] (Synthesis of Compound LC1B)

[0431] In toluene (35 mL) and ethyl acetate (1.5 mL), t-1,4-cyclohexanedicarbonyl chloride (2.0 g), compound LC1A (4.1 g) and methanesulfonyl chloride (0.06 g) were stirred at 90 °C for 2 hours. Then, it was cooled to room temperature, methanol (150 mL) was added and stirred for 30 minutes, and the resulting crystals were filtered to obtain compound LC1B (3.5 g).

[0432] (Synthesis of Compounds LC1C to LC1E)

[0433] Compounds LC1C to LC1E were synthesized with reference to International Publication No. 2022 / 190936.

[0434] (Synthesis of Compound LC1F)

[0435] Methanesulfonyl chloride (1.77 g) was stirred in tetrahydrofuran (6.9 mL) and ethyl acetate (9.7 mL). A solution of LC1E (4.0 g) and triethylamine (1.64 g) in tetrahydrofuran (6.9 mL) was added dropwise at -10 °C, and the mixture was stirred for 1 hour. Then, N-methylimidazole (0.017 g), LC1B (3.69 g), and triethylamine (1.78 g) were added dropwise at 5 °C, and the mixture was stirred at room temperature for 2 hours. In addition, 4 mL of pure water and 60 mL of methanol were added, cooled to 0 °C, and stirred for 1 hour. The resulting crystals were filtered, rinsed with methanol, and then dried by blowing air at 40 °C for 24 hours to obtain Compound LC1F (5.3 g).

[0436] (Synthesis of Polymerizable Liquid Crystal Compound LC1)

[0437] Compound LC1F (4.0 g) and m-chloroperoxybenzoic acid (5.82 g) were stirred in chloroform (40 mL) at 50 °C for 7 hours. Then, a 5 wt% aqueous sodium bisulfite solution was added to remove the aqueous phase, and the mixture was washed successively with aqueous sodium bicarbonate and brine. The organic phase was dried over magnesium sulfate, and after filtering off the magnesium sulfate, it was purified by silica gel chromatography to obtain Polymerizable Liquid Crystal Compound LC1 (1.5 g).

[0438] Of Polymerizable Liquid Crystal Compound LC1 1 1H-NMR (400 MHz, CDCl3): 8.16 (4H, d), 7.81 (2H, d), 7.37 (2H, dd), 7.27 - 7.25 (2H, d), 7.01 - 6.95 (4H, m), 6.42 (2H, dd), 6.13 (2H, dd), 5.84 (2H, dd), 4.39 (2H, dd), 4.28 - 4.23 (4H, m), 4.12 - 4.05 (6H, m), 3.12 - 3.07 (2H, m), 2.72 (2H, dd), 2.68 - 2.60 (2H, m), 2.54 (2H, dd), 2.35 - 2.31 (4H, m), 1.86 - 1.98 (8H, m), 1.78 - 1.65 (4H, m).

[0439] <Example 1>

[0440] (Formation of Alignment Film)

[0441] As the support (first support), a quartz glass substrate was prepared. A coating film was formed by coating a polyimide alignment film-forming composition "SE-130" (manufactured by Nissan Chemical Corporation) on the support. After calcining the obtained coating film, a substrate with an alignment film was produced by performing a rubbing treatment.

[0442] (Formation of the optically anisotropic layer H-1)

[0443] As the composition for forming the optically anisotropic layer, the following composition HL-1 was prepared.

[0444]

[0445]

[0446] UV agent 1: Octyl (2Z,4E)-5-(diethylamino)-2-(phenylsulfonyl)penta-2,4-dienoate

[0447] Leveling agent T-1 (hereinafter, refer to the structural formula)

[0448] [Chemical formula 10]

[0449]

[0450] On the alignment film of the produced substrate with an alignment film, the composition HL-1 was spin-coated at 1000 rpm for 10 seconds to form a coating film, and the coating film was heated at 90 °C for 1 minute (Step 1).

[0451] Next, after cooling the coating film to 30 °C, using a 365 nm LED UV exposure machine in a nitrogen atmosphere, ultraviolet rays with a wavelength of 365 nm were irradiated on the coating film from the side of the quartz glass substrate at an irradiation dose of 2 mJ / cm 2 (Step 2).

[0452] Next, in a nitrogen atmosphere, the light-irradiated coating film was heated at 155 °C for 3 minutes (Step 3).

[0453] Next, in a nitrogen atmosphere and under the condition of 155 °C, using a 365 nm LED UV exposure machine, ultraviolet rays with a wavelength of 365 nm were irradiated on the coating film at an irradiation dose of 1200 mJ / cm 2 to produce an optically anisotropic layer H-1 with a thickness of 1.5 μm.

[0454] In the optically anisotropic layer H-1, there is included one specific region, and the proportion of the specific region in the whole layer is 100% (the whole layer becomes the specific region, and the thickness of the specific region is 1.5 μm).

[0455] (Formation of the optically anisotropic layer I-1)

[0456] The following composition IL-1 was prepared by adding 3 parts by mass of a chiral reagent (Palio color LC756, manufactured by BASF) to the composition HL-1. The amount of the chiral reagent added was adjusted so that the central reflection wavelength of the cholesteric liquid crystal layer obtained using the composition IL-1 was 900 nm.

[0457]

[0458]

[0459] On the alignment film of the substrate with the alignment film fabricated, the composition IL-1 was spin-coated under the conditions of 1000 rpm and 10 seconds to form a coating film, and the coating film was heated at 90 °C for 1 minute (Step 1).

[0460] Next, after cooling the coating film to 30 °C, in a nitrogen atmosphere, using a 365 nm LED UV exposure machine, ultraviolet rays with a wavelength of 365 nm were irradiated onto the coating film from the side of the quartz glass substrate at an irradiation dose of 2 mJ / cm 2 (Step 2).

[0461] Next, in a nitrogen atmosphere, the light-irradiated coating film was heated at 155 °C for 3 minutes (Step 3).

[0462] Next, in a nitrogen atmosphere and under the condition of 155 °C, using a 365 nm LED UV exposure machine, ultraviolet rays with a wavelength of 365 nm were irradiated onto the coating film at an irradiation dose of 1200 mJ / cm 2 to fabricate an optically anisotropic layer I-1 with a thickness of 1.5 μm.

[0463] In the optically anisotropic layer I-1, there is included one specific region, and the proportion of the specific region in the entire layer is 100% (the entire layer becomes the specific region, and the thickness of the specific region is 1.5 μm).

[0464] <Example 2>

[0465] In Step 2 in fabricating the optically anisotropic layer H-1 and Step 2 in fabricating the optically anisotropic layer I-1, ultraviolet rays with a wavelength of 365 nm were irradiated onto the coating film from the air interface side instead of the substrate side at an irradiation dose of 2 mJ / cm 2 , and except for this, the optically anisotropic layers H-1A and I-1A were fabricated in the same manner as in Example 1.

[0466] Next, under the conditions of 1000 rpm and 10 seconds, the compositions HL-1 and IL-1 were spin-coated on the fabricated optical anisotropic layers H-1A and I-1A, respectively, to form coating films, and the coating films were heated at 90 °C for 1 minute.

[0467] Next, after cooling the coating film to 30 °C, using a 365 nm LED UV exposure machine under a nitrogen atmosphere, with an irradiation dose of 100 mJ / cm 2 the coating film was irradiated with ultraviolet light having a wavelength of 365 nm from the side of the quartz glass substrate.

[0468] Next, under a nitrogen atmosphere, the photo-irradiated coating film was heated at 155 °C for 3 minutes.

[0469] Next, under a nitrogen atmosphere and at 155 °C, using a 365 nm LED UV exposure machine with an irradiation dose of 1200 mJ / cm 2 the coating film was irradiated with ultraviolet light having a wavelength of 365 nm, thereby fabricating optical anisotropic layers H-2 and I-2 with a thickness of 3.0 μm, respectively.

[0470] In the optical anisotropic layers H-2 and I-2, as Figure 3 shown, it includes two specific regions, and the proportion of the two specific regions in the whole layer is 100% (the whole layer becomes the specific region, the thickness of each specific region is 1.5 μm, and the total is 3.0 μm).

[0471] <Example 3>

[0472] Using the polymerizable liquid crystal compound LC2 instead of the polymerizable liquid crystal compound LC1, except for this, the optical anisotropic layers H-3 and I-3 were fabricated in the same manner as in Example 1.

[0473] In the optical anisotropic layers H-3 and I-1, as Figure 1 shown, it includes one specific region, and the proportion of the specific region in the whole layer is 20% (the thickness of the specific region is 0.3 μm).

[0474] Polymerizable liquid crystal compound LC2

[0475] [Chemical formula 11]

[0476]

[0477] <Comparative Example 1>

[0478] An optically anisotropic layer HC-1 was produced without using a chiral reagent, otherwise, according to the method described in Example 1 of Japanese Patent Application Laid-Open No. 11-512849. In addition, an optically anisotropic layer IC-1 was produced according to the method described in Example 1 of Japanese Patent Application Laid-Open No. 11-512849.

[0479] <Comparative Example 2>

[0480] (Formation of Optically Anisotropic Layer HC-2)

[0481] As a composition for forming an optically anisotropic layer, the following composition HCL-2 was prepared.

[0482]

[0483]

[0484] On the alignment film of the produced substrate with an alignment film, the composition HCL-2 was spin-coated at 1000 rpm for 10 seconds to form a coating film, and the coating film was heated at 90 °C for 1 minute. Then, in a nitrogen atmosphere and at 90 °C, using a 365 nm LED UV exposure machine, ultraviolet light with a wavelength of 365 nm was irradiated on the coating film at an irradiation dose of 1200 mJ / cm 2 to produce an optically anisotropic layer HC-2 with a thickness of 1.5 μm.

[0485] In the optically anisotropic layer HC-2, the birefringence Δn did not change in the thickness direction.

[0486] (Formation of Optically Anisotropic Layer IC-2)

[0487] As a composition for forming an optically anisotropic layer IC-2, the following composition ICL-2 was prepared.

[0488]

[0489] On the alignment film of the produced substrate with an alignment film, the composition ICL-2 was spin-coated at 1000 rpm for 10 seconds to form a coating film, and the coating film was heated at 90 °C for 1 minute. Then, in a nitrogen atmosphere and at 90 °C, using a 365 nm LED UV exposure machine, ultraviolet light with a wavelength of 365 nm was irradiated on the coating film at an irradiation dose of 1200 mJ / cm 2 to produce an optically anisotropic layer IC-2 with a thickness of 1.5 μm.

[0490] In the optically anisotropic layer IC-2, the birefringence Δn did not change in the thickness direction.

[0491] <Evaluation>

[0492] (Measurement of birefringence Δn)

[0493] The optical anisotropic layer H-1 was etched using a gas cluster ion beam (GCIB), and regions with thicknesses of 0.0 μm, 0.1 μm, 0.2 μm, ……, 1.5 μm were fabricated every 0.1 μm from the interface between the alignment film and the optical anisotropic layer, and each region was designated as region 0, region 1, region 2, ……, region 15. For each region, after measuring the phase difference in the range of 400 to 800 nm using Axoscan (manufactured by Axometrics), based on the difference between regions, the phase difference of each region per 0.1 μm thickness at heights of 0.0 to 0.1 μm, 0.1 to 0.2 μm, ……, 1.4 to 1.5 μm from the interface between the alignment film and the optical anisotropic layer was calculated. In addition, based on the phase difference of each region, the birefringence Δn of each region was calculated. Further, the above phase difference and birefringence Δn are values at a wavelength of 550 nm. In the optical anisotropic layer H-1, Δn at a height of 0.0 to 0.1 μm is 0.06, and Δn at a height of 1.4 to 1.5 μm is 0.01, and the ratio is 6 times.

[0494] Moreover, through the steps described as a) to c) above, the characteristics of wavelength dispersion were determined.

[0495] In the optical anisotropic layer H-1, there is a region where the phase difference and birefringence Δn of each region per 0.1 μm thickness toward one surface side continuously and gradually decrease. And in this region, the wavelength dispersion is constant (that is, Δn450S / Δn550S is within ±5% of Δn450L / Δn550L). Therefore, as Figure 1 shown, the optical anisotropic layer H-1 has a region (specific region) where the birefringence Δn continuously changes in the thickness direction and the wavelength dispersion is constant in the thickness direction. As Figure 1 shown, the specific region is arranged in the thickness direction from one surface of the optical anisotropic layer.

[0496] The above measurement was carried out using the optical anisotropic layers H-2 to H-3 and the optical anisotropic layers I-1 to I-3 instead of the optical anisotropic layer H-...

[0497] Specifically, in the optical anisotropic layer H-3 and the optical anisotropic layers I-1 and I-3, similar to the optical anisotropic layer H-1, there is a region where the phase difference and birefringence Δn of each region per 0.1 μm thickness toward one surface side continuously and gradually decrease and the wavelength dispersion is constant (specific region). AsFigure 1 As shown, a specific region is arranged in the thickness direction from one surface of the optically anisotropic layer.

[0498] In the optically anisotropic layer H-2 and the optically anisotropic layer I-2, as Figure 3 shown, two specific regions are included. That is, one of the two specific regions is located on one surface side of the optically anisotropic layer. In one specific region, the birefringence Δn gradually decreases in the direction from the center position of the film thickness of the optically anisotropic layer toward one surface. The other of the two specific regions is located on the other surface side of the two surfaces of the optically anisotropic layer. In the other specific region, the birefringence Δn gradually decreases in the direction from the center position of the film thickness of the optically anisotropic layer toward the other surface. In addition, in any specific region, the wavelength dispersion is constant in the thickness direction. As Figure 3 shown, one specific region is arranged in the thickness direction from one surface of the optically anisotropic layer, and the other specific region is arranged in the thickness direction from the other surface of the optically anisotropic layer.

[0499] On the other hand, specific regions are not included in the optically anisotropic layers HC-1 and IC-1 and the optically anisotropic layers HC-2 and IC-2.

[0500] (Evaluation of the ratio of birefringence Δn)

[0501] Regarding the optically anisotropic layers H-1 to H-3 having specific regions, among the birefringences Δn of each 0.1-μm-thick region included in each specific region calculated in the above (Measurement of birefringence Δn), the maximum value is set as the birefringence Δn max , and the minimum value is set as the birefringence Δn min , and the ratio of the birefringence Δn max to the birefringence Δn min was evaluated according to the following criteria.

[0502] A: The above ratio is 2.0 or more.

[0503] B: The above ratio is less than 2.0.

[0504] (Measurement of the thickness of the specific region)

[0505] Regarding the optically anisotropic layers H-? to H-3 having specific regions, the thickness of the specific region was calculated and evaluated by the following index.

[0506] A: The thickness of the specific region is 0.5 μm or more.

[0507] B: The thickness of the specific region is less than 0.5 μm.

[0508] (Interface anti-reflection evaluation)

[0509] The transmittance of the optically anisotropic layers H-1 to H-3 and HC-1 to HC-2 at a wavelength of 550 nm was measured using a spectrophotometer (UV-3100, manufactured by Shimadzu Corporation) and evaluated using the following indices: A larger transmittance value indicates better antireflection properties.

[0510] AA: 90.8% or more.

[0511] A: 90.5% or more and less than 90.8%.

[0512] B: 90.3% or more and less than 90.5%.

[0513] C: less than 90.3%.

[0514] (Sidelobe Evaluation)

[0515] The transmittance of the optically anisotropic layers I-1 to I-3 and IC-1 to IC-2 was measured and evaluated at wavelengths of 450 to 650 nm using a spectrophotometer (UV-3100, manufactured by Shimadzu Corporation). A larger transmittance value indicates more suppressed side lobes.

[0516] AA: The average transmittance is 90% or more.

[0517] A: The average transmittance is 89% or more and less than 90%.

[0518] B: The average transmittance is 88% or more and less than 89%.

[0519] C: Average transmittance is less than 88%.

[0520] In the “Liquid Crystal Compound” column in Table 1, “LC1” indicates that the polymerizable liquid crystal compound LC1 was used, and “LC2” indicates that the polymerizable liquid crystal compound LC2 was used.

[0521] In the "Specific Region" column in Table 1, "1" indicates that the optically anisotropic layer includes one specific region, "2" indicates that the optically anisotropic layer includes two specific regions, and "0" indicates that the optically anisotropic layer includes no specific region.

[0522] In Table 1, the column "Δn ratio" shows the evaluation results of the above-mentioned (Evaluation of the ratio of birefringence Δn).

[0523] In Table 1, “Δn max " column indicates the maximum birefringence Δn in a specific area max The value of .

[0524] In Table 1, the column of "Δn min " represents the minimum birefringence Δn min value in a specific region. [[ID=']]

[0525] In Table 1, the column of "thickness of specific region" represents the evaluation result of the above (measurement of the thickness of the specific region).

[0526] In Table 1, the column of "film thickness [μm]" represents the film thickness [μm] of the optically anisotropic layer.

[0527] In Table 1, the column of "thickness of specific region [μm]" represents the thickness [μm] of the specific region.

[0528] In Table 1, the column of "specific region ratio" represents the ratio of the thickness of the specific region to the film thickness of the optically anisotropic layer.

[0529]

[0530] As shown in Table 1 above, it was confirmed that the optically anisotropic layer of the present invention exhibited the desired effect.

[0531] Among them, by comparing Examples 1 to 3, it was confirmed that when the ratio of the birefringence Δn max to the birefringence Δn min was 2.0 or more and the thickness of the specific region was 0.5 μm or more, the effect was more excellent.

[0532] Furthermore, by comparing Examples 1 and 2, it was confirmed that when the optically anisotropic layer had two specific regions, the effect was more excellent.

[0533] <Example 4> <C

[0534] (Formation of photo-alignment film)

[0535] As a support (first support), a glass substrate was prepared. The following photo-alignment film-forming coating solution was applied to the support at 2500 rpm for 30 seconds using a spin coating method. The support having the coating film of the photo-alignment film-forming coating solution was dried on a hot plate at 60 °C for 60 seconds to form a photo-alignment film.

[0536]

[0537] Photo-alignment raw material (hereinafter, with reference to the structural formula)

[0538] [Chemical formula 12]

[0539]

[0540] (Exposure of photo-alignment film)

[0541] Use in an environment with a temperature of 25°C and a relative humidity of 10%. Figure 8 The photo-alignment film was exposed by the exposure apparatus shown, thereby forming a photo-alignment film P-1 having an alignment pattern.

[0542] The exposure device used was a laser that emitted a laser beam with a wavelength of 325 nm. The exposure dose based on the interference light was set to 3000 mJ / cm 2 In addition, the intersection angle (intersection angle α) of the two laser beams was set to 9.3°.

[0543] Optically anisotropic layer I-4 was prepared by applying composition IL-1 in the same manner as in Example 2, except that the photo-alignment film P-1 was used instead of the alignment film. The aforementioned measurement method confirmed that optically anisotropic layer I-4 also had a specific region where the birefringence Δn varied continuously and the wavelength dispersion was constant. Furthermore, visual observation confirmed that no diffraction was observed in the optically anisotropic layer I-4 under visible light, and that visible light diffraction due to side lobes was suppressed.

[0544] Explanation of symbols

[0545] 10A, 10B, 10C-optically anisotropic layer, 12A, 12B-specific regions, 14a, 14b, 14c, 14d-divided regions, 20-oriented substrate, 20-support, 22-oriented film, 24-coating, 26-first region, 28-second region, 30-liquid crystal compound, 30A-optical axis, 40-support, 42-coating, 60-exposure device, 62-laser, 64-light source, 65-λ / 2 plate, 68-beam splitter, 70A, 70B-reflecting mirrors, 72A, 72B-λ / 4 plate.

Claims

1. An optically anisotropic layer formed using a composition containing a liquid crystal compound, wherein, the optically anisotropic layer has at least one region where the birefringence Δn continuously changes in the thickness direction and the wavelength dispersion is constant in the thickness direction.

2. The optically anisotropic layer according to claim 1, wherein, In the region, the birefringence Δn gradually decreases in the direction from one surface of the optically anisotropic layer toward the other surface.

3. The optically anisotropic layer according to claim 1, wherein, The optically anisotropic layer has two such regions, one of the two regions is located on either surface side of the two surfaces of the optically anisotropic layer, in the one region, the birefringence Δn gradually decreases in the direction from the center position of the film thickness of the optically anisotropic layer toward the one surface, the other of the two regions is located on the other surface side of the two surfaces of the optically anisotropic layer, in the other region, the birefringence Δn gradually decreases in the direction from the center position of the film thickness of the optically anisotropic layer toward the other surface.

4. The optically anisotropic layer according to claim 1, wherein, The thickness of the region is 0.5 μm or more.

5. The optically anisotropic layer according to claim 1, wherein, Within the region, the maximum birefringence Δn max is 2.0 or more relative to the minimum birefringence Δn min ratio.

6. The optically anisotropic layer according to claim 1, which is a layer formed by fixing a cholesteric-oriented liquid crystal compound.

7. The optically anisotropic layer according to claim 1, wherein, The liquid crystal compound has a cationic polymerizable group.

8. The optically anisotropic layer according to claim 1, wherein, The composition contains a phenolic compound.

9. The optically anisotropic layer according to claim 1, wherein, The composition contains an ultraviolet absorber.

10. The optically anisotropic layer according to claim 1, which has a liquid crystal alignment pattern in which the orientation of the optical axis derived from the liquid crystal compound continuously rotates and changes along at least one direction in the plane.

11. A method for manufacturing an optically anisotropic layer, which is the method for manufacturing the optically anisotropic layer according to claim 1, and includes: Step 1, using a composition containing a liquid crystal compound having a polymerizable group to form a coating film, and aligning the liquid crystal compound in the formed coating film; Step 2, polymerizing the liquid crystal compound in such a manner that a region where the polymerization rate of the liquid crystal compound continuously changes is formed in the thickness direction of the coating film; and Step 3, performing a heat treatment on the coating film obtained in Step 2 to form a region where the birefringence Δn continuously changes in the thickness direction and the wavelength dispersion is constant.

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