Optically anisotropic layer, optical film, circularly polarizing plate and organic electroluminescence display device

Abstract

To provide an optical anisotropic layer whose linearity of tilt angle variable is high, and with which it is possible to suppress a change of color hue in a front and a diagonal direction when used as a circular polarizing plate in an organic EL display device, as well as an optical film, a circular polarizing plate and an organic EL display device.SOLUTION: Provided is an optical anisotropic layer formed using a liquid crystal composition that contains a liquid crystal compound. The optical anisotropic layer is created by fixing the orientation state of the liquid crystal compound, the orientation state being such that the liquid crystal compound is oriented in twisted nematic mode and the angle of optical axis of the liquid crystal compound against the surface of the optical anisotropic layer successively changes along the thickness direction. The liquid crystal composition contains at least one of the compound expressed by formula (I) and the compound expressed by formula (II) and a rod-like liquid crystal compound having a polymerizable group, that does not correspond to either formula (I) or formula (II).SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an optically anisotropic layer, an optical film, a circular polarizing plate, and an organic electroluminescence display device. [Background technology]

[0002] Optically anisotropic layers having phase difference are used in a wide variety of applications. For example, organic electroluminescence (EL) display devices have a structure using metal electrodes, which may cause problems of contrast reduction and glare due to reflection of external light. Therefore, in order to suppress the adverse effects of external light reflection, circular polarizing plates composed of an optically anisotropic layer and a polarizer have been used.

[0003] As an optically anisotropic layer used in such a circular polarizing plate, for example, Patent Documents 1 and 2 describe the use of a retardation layer formed using a liquid crystal composition containing a liquid crystal compound, in which the liquid crystal compound is fixed in a hybrid orientation. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2018 / 012390 [Patent Document 2] International Publication No. 2015 / 122387 Summary of the Invention [Problem to be solved by the invention]

[0005] Meanwhile, in recent years, in order to further improve image quality in display devices such as organic EL display devices, suppression of black coloring in the front and oblique directions is required. More specifically, currently, organic EL display devices having a circular polarizing plate are required to avoid a coloring in which other colors are mixed into black (hereinafter, also referred to as "color change") when viewed from the front and oblique directions.

[0006] The present inventors have studied the optically anisotropic layers (retardation layers) described in Patent Documents 1 and 2 and have found that the variation of the tilt angle is not linear in some cases. Furthermore, the inventors produced a circular polarizing plate having such an optically anisotropic layer, attached it to a display device, and evaluated its performance, revealing that a change in color occurred in the front direction and in oblique directions (especially in oblique directions).

[0007] Therefore, an object of the present invention is to provide an optically anisotropic layer that has high linearity in the variation of the tilt angle and that can suppress color change in the front direction and oblique directions when used as a circular polarizer in an organic EL display device, as well as an optical film, a circular polarizer, and an organic EL display device. [Means for solving the problem]

[0008] As a result of intensive research to achieve the above object, the inventors have found that, for an optically anisotropic layer in which liquid crystal compounds are fixed in a predetermined alignment state, by specifying the type of liquid crystal compound and a predetermined elastic constant of the liquid crystal composition, the linearity of the variation in the tilt angle can be high and color changes in the front direction and oblique directions can be suppressed when the layer is used as a circular polarizer in an organic EL display device, and thus completed the present invention. That is, it has been found that the above object can be achieved by the following configuration.

[0009] [1] An optically anisotropic layer formed using a liquid crystal composition containing a liquid crystal compound, the optically anisotropic layer is a layer in which the alignment state of a liquid crystal compound is fixed, the alignment state is such that the liquid crystal compound is twisted and the angle of the optical axis of the liquid crystal compound with respect to the surface of the optically anisotropic layer changes continuously along the thickness direction, An optically anisotropic layer, wherein the liquid crystal composition contains at least one of a compound represented by formula (I) described below and a compound represented by formula (II) described below, and a rod-shaped liquid crystal compound having a polymerizable group that does not correspond to either formula (I) or (II) described below. [2] The optically anisotropic layer according to [1], wherein the total content of the compound represented by formula (I) described later and the compound represented by formula (II) described later is 50 mass % or less based on the mass of the rod-like liquid crystal compound. [3] The optically anisotropic layer according to [1] or [2], wherein the liquid crystal composition has a splay elastic constant K11 greater than a bend elastic constant K33. [4] The optically anisotropic layer according to any one of [1] to [3], wherein the liquid crystal composition contains a liquid crystal compound having a bend elastic constant K33 larger than the splay elastic constant K11, and a liquid crystal compound having a bend elastic constant K33 smaller than the splay elastic constant K11. [5] An optically anisotropic layer formed using a liquid crystal composition containing a liquid crystal compound, the optically anisotropic layer is a layer in which the alignment state of a liquid crystal compound is fixed, the alignment state is such that the liquid crystal compound is twisted and the angle of the optical axis of the liquid crystal compound with respect to the surface of the optically anisotropic layer changes continuously along the thickness direction, An optically anisotropic layer, in which a splay elastic constant K11 of a liquid crystal composition is greater than a bend elastic constant K33. [6] An optical film having the optically anisotropic layer according to any one of [1] to [5]. [7] A liquid crystal display having a first optically anisotropic layer and a second optically anisotropic layer, The optical film according to [6], wherein the first optically anisotropic layer is the optically anisotropic layer according to any one of [1] to [5]. [8] A circularly polarizing plate comprising the optical film according to [6] or [7] and a polarizer laminated thereon. [9] An organic electroluminescence display device having the circular polarizing plate according to [8]. Effect of the Invention

[0010] According to the present invention, it is possible to provide an optically anisotropic layer which has high linearity in the variation of the tilt angle and can suppress color change in the front direction and in the oblique direction when used as a circular polarizer in an organic EL display device, as well as an optical film, a circular polarizer, and an organic EL display device. [Brief description of the drawings]

[0011] [Figure 1] FIG. 2 is a schematic diagram illustrating the alignment state of liquid crystal compounds in the optically anisotropic layer of the present invention. [Diagram 2] 2 is a schematic diagram showing the twist direction of a liquid crystal compound when the optically anisotropic layer in FIG. 1 is observed from the normal direction to the layer. FIG. [Diagram 3] FIG. 2 is a diagram for explaining a tilt angle. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The present invention will be described in detail below. The following description of the components may be based on representative embodiments of the present invention, but the present invention is not limited to such embodiments.

[0013] In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits. In the present specification, each component may be used alone or in combination of two or more substances corresponding to each component. When two or more substances are used in combination for each component, the content of the component refers to the total content of the substances used in combination, unless otherwise specified. In this specification, "(meth)acrylate" is used to mean "either one or both of acrylate and methacrylate."

[0014] In this specification, Re(λ) and Rth(λ) respectively represent the in-plane retardation and the retardation in the thickness direction at a wavelength λ. Unless otherwise specified, the wavelength λ is 550 nm. In this specification, Re(λ) and Rth(λ) are values ​​measured at a wavelength λ using an AxoScan (manufactured by Axometrics). By inputting the average refractive index ((nx+ny+nz) / 3) and the film thickness (d(μm)) into AxoScan, In-plane slow axis direction (°) Re(λ)=R0(λ) Rth(λ)=((nx+ny) / 2-nz)×d is calculated. Note that R0(λ) is displayed as a numerical value calculated by AxoScan, but it means Re(λ).

[0015] In this specification, the refractive indices nx, ny, and nz are measured using an Abbe refractometer (NAR-4T, manufactured by Atago Co., Ltd.) and a sodium lamp (λ=589 nm) as a light source. In addition, when measuring wavelength dependency, it can be measured using a multi-wavelength Abbe refractometer DR-M2 (manufactured by Atago Co., Ltd.) in combination with an interference filter. In addition, values ​​from the Polymer Handbook (JOHN WILEY & SONS, INC.) and catalogs of various optical films can be used. The average refractive index values ​​of major optical films are shown below as examples: cellulose acylate (1.48), cycloolefin polymer (1.52), polycarbonate (1.59), polymethyl methacrylate (1.49), and polystyrene (1.59).

[0016] [Optical anisotropic layer] The optically anisotropic layer of the present invention, i.e., the optically anisotropic layer according to the first and second aspects of the present invention described below, is an optically anisotropic layer formed using a liquid crystal composition containing the liquid crystal compound of the present invention. The optically anisotropic layer of the present invention is a layer in which the alignment state of liquid crystal compounds is fixed. The orientation state of the liquid crystal compound in the optically anisotropic layer of the present invention is such that the liquid crystal compound is twisted and the angle of the optical axis of the liquid crystal compound with respect to the surface of the optically anisotropic layer changes continuously along the thickness direction. Hereinafter, such an orientation state of the liquid crystal compound is also called twist hybrid orientation. Here, the optical axis of a liquid crystal compound refers to the long axis direction of a liquid crystal molecule in the case of a rod-shaped liquid crystal compound, and refers to the direction perpendicular to the disc surface in the case of a discotic liquid crystal compound.

[0017] The twisted hybrid orientation will be described below with reference to the drawings. Fig. 1 shows an example of an optically anisotropic layer 10 in which liquid crystal compounds in a twist hybrid orientation are fixed. Fig. 2 shows a schematic diagram showing the twist direction of the liquid crystal compound when the optically anisotropic layer 10 in Fig. 1 is observed from the normal direction of the optically anisotropic layer 10. Although Figs. 1 and 2 show an example in which a rod-shaped liquid crystal compound is used as the liquid crystal compound, the liquid crystal compound is not limited to only rod-shaped liquid crystal compounds, as shown in the optically anisotropic layer according to the second embodiment of the present invention described later. In the embodiment shown in FIG. 1, the tilt angle of the liquid crystal compound LC in the optically anisotropic layer 10 increases from one surface 10A of the optically anisotropic layer 10 toward the other surface 10B. Here, as shown in FIG. 3, the tilt angle of the liquid crystal compound LC means the angle θ formed between the optical axis of the liquid crystal compound LC and the projected component LCxy of the optical axis of the liquid crystal compound with respect to the main surface of the optical anisotropic layer (the xy plane in FIG. 1). 1 and 2, the liquid crystal compound LC in the optically anisotropic layer 10 is twisted and aligned with the thickness direction as the axis of rotation. That is, the liquid crystal compound rotates from one surface (principal surface) to the other surface (principal surface) of the optically anisotropic layer with the axis along the thickness direction as the axis of rotation. Here, as shown in FIG. 2, the twist angle φ of a liquid crystal compound indicates the degree to which the liquid crystal compound is twisted from one surface side to the other surface side, and the twist angle in this specification means the angle between the optical axis on one surface and the optical axis on the other surface in a diagram in which the optical axis of the liquid crystal compound is projected onto a plane when the optically anisotropic layer is observed from the normal direction. The tilt angle and torsion angle (hereinafter also referred to as "twist angle") are measured using an AxoScan (polarimeter) device manufactured by Axometrics, Inc., and the device analysis software of the same company.

[0018] In the optically anisotropic layer of the present invention, the difference between the tilt angle θ1 of the liquid crystal compound on one surface (for example, the surface on the alignment film side when the optical film described later has an alignment film) and the tilt angle θ2 of the liquid crystal compound on the other surface (for example, the surface on the second optically anisotropic layer side when the optical film described later has a second optically anisotropic layer) is not particularly limited, but is preferably 5 to 85°, and more preferably 15 to 75°, in terms of better effects of the present invention. θ1 is preferably from 0 to 75°, and more preferably from 0 to 65°. θ2 is preferably from 0 to 85°, and more preferably from 0 to 75°. The average of θ1 and θ2 is not particularly limited, but in terms of superior effects of the present invention, it is preferably 15° or more and less than 45°, and more preferably 20° or more and less than 45°.

[0019] In the optically anisotropic layer of the present invention, the twist angle of the liquid crystal compound is preferably from 10 to 180°, more preferably from 55 to 120°.

[0020] The optically anisotropic layer according to the first aspect of the present invention is a layer in which a twist hybrid alignment of a liquid crystal compound is fixed, and the liquid crystal composition forming the optically anisotropic layer contains at least one of a compound represented by the following formula (I) (hereinafter also abbreviated as "compound I") and a compound represented by the following formula (II) (hereinafter also abbreviated as "compound II"), and a rod-like liquid crystal compound having a polymerizable group that does not correspond to either of the following formulas (I) or (II). The symbols in the following formulas (I) and (II) will be described later. [ka] JPEG0007602367000002.jpg1098

[0021] The optically anisotropic layer according to the first aspect of the present invention is formed using a liquid crystal composition containing at least one of compound I and compound II together with a rod-shaped liquid crystal compound having a polymerizable group, and therefore has high linearity in the variation of tilt angle, and can suppress color change in the front direction and oblique direction when used as a circular polarizer in an organic EL display device. Although the details of the reason for this are not yet clear, the present inventors speculate that it is due to the following reasons. In the first embodiment of the present invention, the bend elastic constant K33 is reduced by blending at least one of compound I and compound II in the liquid crystal composition, and as a result, when twist hybrid alignment is adopted, the bend distortion amount is large and the liquid crystal composition can be energetically stabilized. That is, in the first embodiment of the present invention, the state where the bend distortion amount is large is advantageous for linearity, so that the linearity of the variation of the tilt angle is high, and it is considered that the color change in the front direction and the oblique direction can be suppressed when the liquid crystal composition is used as a circular polarizer in an organic EL display device.

[0022] Each component of the liquid crystal composition forming the optically anisotropic layer according to the first embodiment of the present invention (hereinafter also formally abbreviated as "liquid crystal composition according to the first embodiment of the present invention") will be described in detail below.

[0023] [Compound I] Compound I is a compound represented by the following formula (I). [ka]

[0024] In the above formula (I), P 1 and P 2 each independently represents a hydrogen atom or a substituent. Also, S 1 and S 2 each independently represents a single bond or a divalent linking group. Also, A 1 , A 2 , A 3 and A 4each independently represents a non-aromatic ring, an aromatic ring, or an aromatic heterocyclic ring, which may have a substituent. 1 If there are multiple A's, multiple A's 1 may be the same or different, and A 4 If there are multiple A's, multiple A's 4 may be the same or different. Also, Y 1 and Y 2 each independently represents -O-, -S-, -OCH2-, -CHO-, -CH2CH2-, -CO-, -COO-, -OCO-, -CO-S-, -S-CO-, -O-CO-O-, -CO-NH-, -NH-CO-, -SCH2-, -CH2S-, -CF2O-, -OCF2-, -CF2S-, -SCF2-, -CH=CH-COO-, -CH=CH-OCO-, -COO-CH=CH-, -OCO-CH=CH-, -CH=CH-, -N=N-, -CH=NN=CH-, -CF=CF-, -C≡C-, or a single bond. 1 If there are multiple Ys, 1 may be the same or different, Y 2 If there are multiple Ys, 2 may be the same or different. Furthermore, m1 and m2 each independently represent an integer of 0 to 5. Z represents a linear or branched alkylene group having no aromatic substituent. 2 and A 3 and the number of atoms on the bond connecting them at the shortest distance is 3 or more, and one -CH2- or two or more non-adjacent -CH2- constituting the alkylene group may be substituted with -O-, -COO-, -OCO-, -OCOO-, -NRCO-, -CONR-, -NRCOO-, -OCONR-, -CO-, -S-, -SO2-, -NR-, -NRSO2-, or -SO2NR-. R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

[0025] In the above formula (I), P 1 and P 2Examples of the substituent represented by one embodiment of the formula (1) include an alkyl group, an alkoxy group, an alkylcarbonyl group, an alkoxycarbonyl group, an alkylcarbonyloxy group, an alkylamino group, a dialkylamino group, an alkylamide group, an alkenyl group, an alkynyl group, a halogen atom, a cyano group, a nitro group, an alkylthiol group, an N-alkylcarbamate group, and a polymerizable group. Among these, an alkyl group, an alkoxy group, or a polymerizable group is preferable.

[0026] The alkyl group, which is a suitable example of the substituent, is preferably a linear, branched or cyclic alkyl group having 1 to 18 carbon atoms, and more preferably an alkyl group having 1 to 12 carbon atoms (for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a t-butyl group, a hexylene group, a heptyl group, a dodecyl group, a cyclohexyl group, etc.).

[0027] The alkoxy group, which is a suitable example of the substituent, is preferably an alkoxy group having 1 to 18 carbon atoms, and more preferably an alkoxy group having 1 to 12 carbon atoms (for example, a methoxy group, an ethoxy group, an n-butoxy group, a methoxyethoxy group, etc.).

[0028] The polymerizable group, which is a suitable example of the substituent, is not particularly limited, but is preferably a polymerizable group capable of radical polymerization or cationic polymerization. As the radical polymerizable group, a generally known radical polymerizable group can be used, and a suitable one can be an acryloyloxy group or a methacryloyloxy group.In this case, it is known that the polymerization rate of the acryloyloxy group is generally fast, and from the viewpoint of improving productivity, the acryloyloxy group is preferred, but the methacryloyloxy group can also be used as the polymerizable group. As the cationic polymerizable group, a generally known cationic polymerizable group can be used, and specific examples thereof include an alicyclic ether group, a cyclic acetal group, a cyclic lactone group, a cyclic thioether group, a spiro orthoester group, and a vinyloxy group. Among these, an alicyclic ether group or a vinyloxy group is preferred, and an epoxy group, an oxetanyl group, or a vinyloxy group is particularly preferred. Particularly preferred examples of the polymerizable group include polymerizable groups represented by any of the following formulae (P-1) to (P-20). Among them, polymerizable groups represented by any of the following formulae (P-1), (P-2), (P-7) and (P-12) are preferred.

[0029] [ka]

[0030] In the present invention, the durability of the optically anisotropic layer to be produced is improved. 1 and P 2 It is preferable that at least one of P represents a polymerizable group. 1 and P 2 It is more preferable that both of the following groups represent a polymerizable group.

[0031] In the above formula (I), S 1 and S 2 Examples of the divalent linking group in one embodiment include -O-, -S-, -OCH2-, -CHO-, -CH2CH2-, -CO-, -COO-, -OCO-, -CO-S-, -S-CO-, -O-CO-O-, -CO-NH-, and -NH-CO-. Among these, -O-, -CO-, -COO-, and -OCO- are preferable. 1 and S 2 It is also preferable that the group is a single bond.

[0032] In the above formula (I), A 1 , A 2 , A 3 and A 4An example of the non-aromatic ring in one embodiment of the above is a cycloalkane ring. Specific examples of the cycloalkane ring include a cyclohexane ring, a cycloheptane ring, a cyclooctane ring, a cyclododecane ring, and a cyclodocosane ring. Of these, a cyclohexane ring is preferred, a 1,4-cyclohexylene group is more preferred, and a trans-1,4-cyclohexylene group is even more preferred.

[0033] In addition, in the above formula (I), A 1 , A 2 , A 3 and A 4 Examples of the aromatic ring in one embodiment of the above include a benzene ring, a naphthalene ring, and an anthracene ring. Of these, a benzene ring (eg, 1,4-phenyl group) and a naphthalene ring are preferred.

[0034] In addition, in the above formula (I), A 1 , A 2 , A 3 and A 4 Examples of the aromatic heterocycle in one embodiment of the present invention include a furan ring, a pyrrole ring, a thiophene ring, an oxadiazole ring (1,3,4-oxadiazole), a thiadiazole ring (1,3,4-thiadiazole), a pyridine ring, a pyrazine ring (1,4-diazine), a pyrimidine ring (1,3-diazine), a pyridazine ring (1,2-diazine), a thiazole ring, a benzothiazole ring, and a phenanthroline ring. Of these, a thiophene ring, an oxadiazole ring, a thiadiazole ring, a pyridine ring, and a pyrimidine ring are preferred.

[0035] In addition, in the above formula (I), A 1 , A 2 , A 3 and A 4 The substituent that may be possessed by the above formula (I) is 1 and P 2Among them, an alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group, or a halogen atom is preferable. The alkyl group is preferably a linear, branched or cyclic alkyl group having 1 to 18 carbon atoms, more preferably an alkyl group having 1 to 8 carbon atoms (e.g., a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a t-butyl group, a cyclohexyl group, etc.), still more preferably an alkyl group having 1 to 4 carbon atoms, and particularly preferably a methyl group or an ethyl group. The alkoxy group is preferably an alkoxy group having 1 to 18 carbon atoms, more preferably an alkoxy group having 1 to 8 carbon atoms (for example, a methoxy group, an ethoxy group, an n-butoxy group, a methoxyethoxy group, etc.), still more preferably an alkoxy group having 1 to 4 carbon atoms, and particularly preferably a methoxy group or an ethoxy group. Examples of the alkoxycarbonyl group include groups in which an oxycarbonyl group (-O-CO- group) is bonded to the alkyl group exemplified above. Among these, a methoxycarbonyl group, an ethoxycarbonyl group, an n-propoxycarbonyl group or an isopropoxycarbonyl group is preferred, and a methoxycarbonyl group is more preferred. Examples of the alkylcarbonyloxy group include groups in which a carbonyloxy group (-CO-O- group) is bonded to the alkyl group exemplified above. Among these, a methylcarbonyloxy group, an ethylcarbonyloxy group, an n-propylcarbonyloxy group, or an isopropylcarbonyloxy group is preferable, and a methylcarbonyloxy group is more preferable. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and among these, a fluorine atom or a chlorine atom is preferable.

[0036] In the above formula (I), Y 1 and Y 2As described above, each independently represents -O-, -S-, -OCH2-, -CHO-, -CH2CH2-, -CO-, -COO-, -OCO-, -CO-S-, -S-CO-, -O-CO-O-, -CO-NH-, -NH-CO-, -SCH2-, -CH2S-, -CF2O-, -OCF2-, -CF2S-, -SCF2-, -CH=CH-COO-, -CH=CH-OCO-, -COO-CH=CH-, -OCO-CH=CH-, -CH=CH-, -N=N-, -CH=NN=CH-, -CF=CF-, -C≡C-, or a single bond. Among these, any of -O-, -CO-, -COO-, -OCO-, -C≡C- and a single bond is preferable.

[0037] In the above formula (I), m1 and m2 each independently represent an integer of 0 to 5, preferably an integer of 1 to 4, and more preferably 1 or 2, as described above.

[0038] In the above formula (I), Z represents a linear or branched alkylene group having no aromatic substituent, as described above. 2 and A 3 The number of atoms in the shortest bond connecting and is three or more. In addition, one -CH2- or two or more non-adjacent -CH2- constituting the alkylene group represented by Z may be substituted with -O-, -COO-, -OCO-, -OCOO-, -NRCO-, -CONR-, -NRCOO-, -OCONR-, -CO-, -S-, -SO2-, -NR-, -NRSO2-, or -SON2NR-. R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Even when substituted with a divalent linking group composed of multiple atoms such as -COO-, the target of substitution is one -CH2-. In addition, the aromatic substituent that the alkylene group represented by Z does not have refers to an aromatic hydrocarbon ring group, an aromatic heterocyclic group, etc., which may have a substituent, and examples thereof include a phenyl group, a toluyl group, a naphthyl group, and a pyridyl group. Also, A 2 and A 3The number of atoms on the bond connecting the shortest distance between and is, as described above, 3 or more, but is preferably an odd number of 11 or less, and more preferably 3, 5, 7, or 9. Here, "A 2 -ZA 3 An example of the partial structure of " is represented by the following formula. 2 and A 3 The number of atoms on the bond connecting and at the shortest distance is 6, as shown in the formula below. [ka]

[0039] Examples of the alkylene group represented by Z include linear or branched alkylene groups having 3 or 5 to 12 carbon atoms. Specific examples of suitable alkylene groups include a propylene group, a pentylene group, a hexylene group, a methylhexylene group, a heptylene group, an octylene group, a nonylene group, and a dodecylene group. Moreover, among the above, -O-, -COO-, -OCO-, -S- and -NR- are preferable as the substituents for replacing -CH2- constituting the alkylene group represented by Z.

[0040] Specific examples of compound I include compounds I-1 to I-33 shown below. [ka] JPEG0007602367000007.jpg55147JPEG0007602367000008.jpg60143JPEG0007602367000009.jpg63141JPEG0007602367000010.jpg48161 JPEG0007602367000011.jpg53156JPEG0007602367000012.jpg81166JPEG0007602367000013.jpg54151JPEG0007602367000014.jpg70167

[0041] [Compound II] Compound II is a compound represented by the following formula (II). [ka]

[0042] In the above formula (II), P 3 and P 4 each independently represents a hydrogen atom or a substituent. Also, S 3 and S 4 each independently represents a single bond or a divalent linking group. Also, A 5 and A 6 each independently represents a non-aromatic ring, an aromatic ring, or an aromatic heterocyclic ring, which may have a substituent. 5 If there are multiple A's, multiple A's 5 may be the same or different, and A 6 If there are multiple A's, multiple A's 6 may be the same or different. Also, Y 3 and Y 4 each independently represents -O-, -S-, -OCH2-, -CHO-, -CH2CH2-, -CO-, -COO-, -OCO-, -CO-S-, -S-CO-, -O-CO-O-, -CO-NH-, -NH-CO-, -SCH2-, -CH2S-, -CF2O-, -OCF2-, -CF2S-, -SCF2-, -CH=CH-COO-, -CH=CH-OCO-, - COO-CH=CH-, -OCO-CH=CH-, -COO-CH2CH2-, -OCO-CH2CH2-, -CH2CH2-COO-, -CH2CH2-OCO-, -COO-CH2-, -OCO-CH2-, -CH2-COO-, -CH2-OCO-, -CH=CH-, -N=N-, -CH=NN=CH-, -CF=CF-, -C≡C-, or a single bond. 3 If there are multiple Ys, 3 may be the same or different, Y 4 If there are multiple Ys, 4 may be the same or different. Furthermore, m3 and m4 each independently represent an integer of 1 to 5. Furthermore, B represents any one of the groups represented by the following formulae (B-1) to (B-11), which may have a substituent. [ka] However, the carbon atoms in the above formulae (B-1) to (B-11) may be substituted with a nitrogen atom, an oxygen atom or a sulfur atom. X in the above formulae (B-4) to (B-8), (B-10) and (B-11) represents a nitrogen atom, an oxygen atom or a sulfur atom, the two X in the above formula (B-5) may each be the same atom or different atoms, and the two X in the above formula (B-6) may each be the same atom or different atoms. When B is a group represented by the above formula (B-11), Y bonded to B 3 and Y 4 Each of them represents a single bond.

[0043] In the above formula (II), P 3 and P 4 As a substituent represented by one embodiment of the formula (I), 1 and P 2 The same substituents as those shown in one embodiment of the above can be mentioned, and preferred embodiments are also the same.

[0044] In the present invention, the durability of the optically anisotropic layer to be produced is improved. 3 and P 4 It is preferable that at least one of P represents a polymerizable group. 3 and P 4 It is more preferable that both of the following groups represent a polymerizable group.

[0045] In the above formula (II), S 3 and S 4 As a divalent linking group in one embodiment, there is S 3 and S 4 The divalent linking group may be the same as that shown in one embodiment of the above, and the preferred embodiments are also the same.3 and S 4 It is also preferable that the group is a single bond.

[0046] In the above formula (II), A 5 and A 6 The "optionally substituted non-aromatic ring, aromatic ring or aromatic heterocyclic ring" represented by A in the above formula (I) is 1 , A 2 , A 3 and A 4 The examples of the "optionally substituted non-aromatic ring, aromatic ring or aromatic heterocyclic ring" include those shown in the above, and preferred embodiments are also the same.

[0047] In the above formula (II), Y 3 and Y 4 As described above, each independently represents -O-, -S-, -OCH2-, -CHO-, -CH2CH2-, -CO-, -COO-, -OCO-, -CO-S-, -S-CO-, -O-CO-O-, -CO-NH-, -NH-CO-, -SCH2-, -CH2S-, -CF2O-, -OCF2-, -CF2S-, -SCF2-, -CH=CH-COO-, -CH=CH-OCO It represents -, -COO-CH=CH-, -OCO-CH=CH-, -COO-CH2CH2-, -OCO-CH2CH2-, -CH2CH2-COO-, -CH2CH2-OCO-, -COO-CH2-, -OCO-CH2-, -CH2-COO-, -CH2-OCO-, -CH=CH-, -N=N-, -CH=NN=CH-, -CF=CF-, -C≡C-, or a single bond. Among these, any of -COO-, -OCO-, -CO-NH-, -NH-CO-, -CH=CH-, -N=N-, -C≡C-, and a single bond is preferable.

[0048] In the above formula (II), m3 and m4 are each independently an integer of 1 to 5, preferably an integer of 1 to 4, and more preferably an integer of 1 to 3, as described above.

[0049] In the above formula (II), B represents any one of the groups represented by the above formulas (B-1) to (B-11), which may have a substituent, as described above. Here, examples of the substituent that may be possessed by any of the groups represented by the above formulas (B-1) to (B-11) include P 1 and P 2 Among them, an alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group, or a halogen atom is preferable. Specific examples of these are the same as those of the A in the above formula (I). 1 , A 2 , A 3 and A 4 The specific examples of the substituent that may be possessed by the group are the same as those of the substituent that may be possessed by the group.

[0050] Specific examples of Compound II include Compound II-1 to Compound II-32 shown below. [ka] JPEG0007602367000018.jpg87145JPEG0007602367000019.jpg141160JPEG0007602367000020.jpg99166JPEG000760236700 0021.jpg113165JPEG0007602367000022.jpg110127JPEG0007602367000023.jpg120165JPEG0007602367000024.jpg101150

[0051] In the present invention, from the viewpoint of adjusting the ratio (K33 / K11) of the bend elastic constant (K33) to the splay elastic constant (K11) of the liquid crystal composition, the total content of the compound I and the compound II is preferably 50 mass % or less, more preferably 5 to 35 mass %, based on the mass of the rod-shaped liquid crystal compound described later.

[0052] [Rod-shaped liquid crystal compound] The rod-shaped liquid crystal compound contained in the liquid crystal composition according to the first embodiment of the present invention is a rod-shaped liquid crystal compound having a polymerizable group. Here, the polymerizable group is, for example, P 1 and P 2 As a suitable example of the substituent in one embodiment of the present invention, the polymerizable group represented by any one of the formulas (P-1) to (P-20) is mentioned. Among them, the polymerizable group represented by the formula (P-1) or (P-2) is preferable.

[0053] Examples of the rod-shaped liquid crystal compound include azomethines, azoxys, cyanobiphenyls, cyanophenyl esters, benzoates, cyclohexane carboxylic acid phenyl esters, cyanophenylcyclohexanes, cyano-substituted phenylpyrimidines, alkoxy-substituted phenylpyrimidines, phenyldioxanes, tolanes, and alkenylcyclohexylbenzonitriles. In addition to the low molecular weight liquid crystal compounds as described above, polymeric liquid crystal compounds are also included.

[0054] Specific examples of the rod-shaped liquid crystal compound include those described in Makromol. Chem., Vol. 190, p. 2255 (1989), Advanced Materials, Vol. 5, p. 107 (1993), U.S. Patent Nos. 4,683,327, 5,622,648, and 5,770,107, WO95 / 22586, 95 / 24455, 97 / 00600, 98 / 23580, and 98 / 52905, JP-A-1-272551, JP-A-6-16616, JP-A-7-110469, JP-A-11-80081, and Japanese Patent Application No. 2001-64627.

[0055] In the present invention, the rod-shaped liquid crystal compound may be a liquid crystal compound having forward wavelength dispersion or a liquid crystal compound having reverse wavelength dispersion. When the liquid crystal compound has forward wavelength dispersion, the production cost of the optical film is reduced and durability is improved, which is preferable. In this specification, a liquid crystal compound with forward wavelength dispersion is one in which, when the in-plane retardation (Re) value in the visible light range of an optically anisotropic layer prepared using this liquid crystal compound is measured, the Re value decreases as the measured wavelength increases, whereas a liquid crystal compound with reverse wavelength dispersion is one in which, when the Re value is similarly measured, the Re value increases as the measured wavelength increases.

[0056] In the present invention, the content of the rod-shaped liquid crystal compound is preferably 50 to 90% by mass, and more preferably 60 to 80% by mass, based on the solid content mass (mass excluding the solvent) of the liquid crystal composition.

[0057] [Surfactant] The liquid crystal composition according to the first embodiment of the present invention may contain a surfactant. The surfactant is preferably a compound that can function as an alignment control agent that contributes to the alignment of the cholesteric liquid crystal phase stably or quickly. Examples of the surfactant include silicone surfactants and fluorine surfactants, and fluorine surfactants are preferred.

[0058] Specific examples of surfactants include the compounds described in paragraphs

[0082] to

[0090] of JP 2014-119605 A, the compounds described in paragraphs

[0031] to

[0034] of JP 2012-203237 A, the compounds exemplified in paragraphs

[0092] and

[0093] of JP 2005-99248 A, the compounds exemplified in paragraphs

[0076] to

[0078] and paragraphs

[0082] to

[0085] of JP 2002-129162 A, and the fluorine (meth)acrylate polymers described in paragraphs

[0018] to

[0043] of JP 2007-272185 A, etc. The surfactant may be used alone or in combination of two or more kinds. As the fluorine-based surfactant, the compounds described in paragraphs

[0082] to

[0090] of JP2014-119605A are preferred.

[0059] The amount of the optional surfactant added is preferably 0.01 to 10% by mass, more preferably 0.01 to 5% by mass, and further preferably 0.02 to 1% by mass, based on the mass of the rod-like liquid crystal compound.

[0060] [Chiral Agents (Optically Active Compounds)] The liquid crystal composition according to the first aspect of the present invention may contain a chiral agent. Chiral agents have the function of inducing a helical structure in the cholesteric liquid crystal phase. Chiral agents can be selected according to the purpose, since the twist direction or pitch of the helix induced varies depending on the compound. The chiral agent is not particularly limited, and known compounds (for example, those described in Liquid Crystal Device Handbook, Chapter 3, Section 4-3, Chiral Agents for TN (twisted nematic) and STN (Super Twisted Nematic), p. 199, edited by the 142nd Committee of the Japan Society for the Promotion of Science, 1989), isosorbide, and isomannide derivatives can be used. Although the chiral agent generally contains an asymmetric carbon atom, an axially asymmetric compound or a planarly asymmetric compound that does not contain an asymmetric carbon atom can also be used as the chiral agent. Examples of the axially asymmetric compound or the planarly asymmetric compound include binaphthyl, helicene, paracyclophane, and derivatives thereof. The chiral agent may have a polymerizable group. When both the chiral agent and the liquid crystal compound have a polymerizable group, a polymer having a repeating unit derived from the polymerizable liquid crystal compound and a repeating unit derived from the chiral agent can be formed by a polymerization reaction between the polymerizable chiral agent and the polymerizable liquid crystal compound. In this embodiment, the polymerizable group of the polymerizable chiral agent is preferably the same type of group as the polymerizable group of the polymerizable liquid crystal compound. Therefore, the polymerizable group of the chiral agent is also preferably an unsaturated polymerizable group, an epoxy group, or an aziridinyl group, more preferably an unsaturated polymerizable group, and even more preferably an ethylenically unsaturated polymerizable group. The chiral agent may also be a liquid crystal compound.

[0061] When the chiral agent has a photoisomerizable group, it is preferable because a pattern of a desired reflection wavelength corresponding to the emission wavelength can be formed by irradiating a photomask with actinic rays or the like after coating and alignment. As the photoisomerizable group, an isomerization site of a compound exhibiting photochromic properties, an azo group, an azoxy group, or a cinnamoyl group is preferable. Specific compounds that can be used include those described in JP-A-2002-080478, JP-A-2002-080851, JP-A-2002-179668, JP-A-2002-179669, JP-A-2002-179670, JP-A-2002-179681, JP-A-2002-179682, JP-A-2002-338575, JP-A-2002-338668, JP-A-2003-313189, and JP-A-2003-313292.

[0062] The content of the optional chiral dopant is preferably from 0.01 to 200 mol %, more preferably from 1 to 30 mol %, based on the molar amount of the rod-like liquid crystal compound.

[0063] [Polymerization initiator] The liquid crystal composition according to the first aspect of the present invention preferably contains a polymerization initiator. In an aspect in which the polymerization reaction is caused to proceed by irradiation with ultraviolet light, the polymerization initiator used is preferably a photopolymerization initiator capable of initiating the polymerization reaction by irradiation with ultraviolet light. Examples of the photopolymerization initiator include α-carbonyl compounds (described in U.S. Pat. Nos. 2,367,661 and 2,367,670), acyloin ethers (described in U.S. Pat. No. 2,448,828), α-hydrocarbon-substituted aromatic acyloin compounds (described in U.S. Pat. No. 2,722,512), polynuclear quinone compounds (described in U.S. Pat. Nos. 3,046,127 and 2,951,758), combinations of triarylimidazole dimers and p-aminophenyl ketones (described in U.S. Pat. No. 3,549,367), acridine and phenazine compounds (described in JP-A-60-105,667 and U.S. Pat. No. 4,239,850), and oxadiazole compounds (described in U.S. Pat. No. 4,212,970). The content of the optional photopolymerization initiator is preferably 0.1 to 20% by mass, more preferably 0.5 to 12% by mass, based on the mass of the rod-like liquid crystal compound.

[0064] [Crosslinking Agent] The liquid crystal composition according to the first aspect of the present invention may contain a crosslinking agent in order to improve the film strength and durability after curing. As the crosslinking agent, those which are cured by ultraviolet light, heat, moisture, etc. can be suitably used. The crosslinking agent is not particularly limited and can be appropriately selected according to the purpose. For example, polyfunctional acrylate compounds such as trimethylolpropane tri(meth)acrylate and pentaerythritol tri(meth)acrylate; epoxy compounds such as glycidyl (meth)acrylate and ethylene glycol diglycidyl ether; aziridine compounds such as 2,2-bishydroxymethylbutanol-tris[3-(1-aziridinyl)propionate] and 4,4-bis(ethyleneiminocarbonylamino)diphenylmethane; isocyanate compounds such as hexamethylene diisocyanate and biuret type isocyanate; polyoxazoline compounds having an oxazoline group in the side chain; and alkoxysilane compounds such as vinyltrimethoxysilane and N-(2-aminoethyl)3-aminopropyltrimethoxysilane. In addition, a known catalyst can be used according to the reactivity of the crosslinking agent, which can improve productivity in addition to improving the film strength and durability. These may be used alone or in combination of two or more. The content of the optional crosslinking agent is preferably 3 to 20% by mass, more preferably 5 to 15% by mass, based on the solid content mass of the liquid crystal composition. If the content of the crosslinking agent is within the above range, the durability of the produced optical element is improved.

[0065] [Other additives] If necessary, a polymerization inhibitor, an antioxidant, an ultraviolet absorber, a light stabilizer, a colorant, metal oxide fine particles, and the like can be further added to the liquid crystal composition related to the first aspect of the present invention within a range that does not deteriorate the optical performance, etc.

[0066] The liquid crystal composition according to the first aspect of the present invention is preferably used as a liquid when forming an optically anisotropic layer. The liquid crystal composition may contain a solvent. The solvent is not particularly limited and can be appropriately selected depending on the purpose, but an organic solvent is preferable. Examples of organic solvents include ketones, alkyl halides, amides, sulfoxides, heterocyclic compounds, hydrocarbons, esters, and ethers. These may be used alone or in combination of two or more. Among these, ketones are preferred in consideration of the environmental load.

[0067] In the liquid crystal composition according to the first aspect of the present invention, it is preferable that the splay elastic constant K11 of the liquid crystal composition is larger than the bend elastic constant K33, because this leads to higher linearity of the variation of the tilt angle and also leads to good linearity of the variation of the twist angle. Here, the elastic constant of the liquid crystal composition is the elastic constant of the liquid crystal composition excluding the solvent. The magnitude relationship between the elastic constant K11 of the splay and the elastic constant K33 of the bend can be determined by whether the ratio (K11 / K33) of the elastic constant K11 of the splay to the elastic constant K33 of the bend is greater than 1 or not. The ratio of the splay elastic constant K11 to the bend elastic constant K33 (K11 / K33) refers to a value measured according to the method described in the literature "Sen-i to Kogyo Vol. 42, No. 11 (1986), 449."

[0068] In addition, the ratio (K11 / K33) of the splay elastic constant K11 to the bend elastic constant K33 of the liquid crystal composition according to the first embodiment of the present invention is preferably 1.0 or more, more preferably 1.1 or more. There is no particular upper limit, but it is usually preferably 10 or less.

[0069] The liquid crystal composition according to the first aspect of the present invention preferably contains a liquid crystal compound having a bend elastic constant K33 larger than the splay elastic constant K11 (hereinafter also abbreviated as "compound L") and a liquid crystal compound having a bend elastic constant K33 smaller than the splay elastic constant K11 (hereinafter also abbreviated as "compound R").

[0070] Here, examples of the compound L include the above-mentioned rod-shaped liquid crystal compounds and discotic liquid crystal compounds. The discotic liquid crystal compound is not particularly limited, and examples thereof include the liquid crystal compounds described in paragraphs

[0020] to

[0067] of JP-A-2007-108732 and paragraphs

[0013] to

[0108] of JP-A-2010-244038. In addition, the discotic liquid crystal compound preferably has a polymerizable group. The type of the polymerizable group is not particularly limited, and P in the above formula (I) 1 and P 2 As a suitable example of the substituent in one embodiment of the present invention, the polymerizable group represented by any one of the formulas (P-1) to (P-20) is mentioned. Among them, the polymerizable group represented by the formula (P-1) or (P-2) is preferable. On the other hand, examples of compound R include the above-mentioned compounds I and II.

[0071] A method for producing the optically anisotropic layer according to the first aspect of the present invention includes coating the liquid crystal composition according to the first aspect of the present invention described above to form a coating film, performing an alignment treatment on the coating film to align the liquid crystal compound, and performing a curing treatment. There is no particular limitation on the object to which the liquid crystal composition is applied, and examples thereof include a support to be described later, or a second optically anisotropic layer to be described later. In addition, in order to make the direction of the in-plane slow axis of the formed optically anisotropic layer a predetermined direction, the object on which the liquid crystal composition is applied may be subjected to a rubbing treatment. For example, a long support subjected to a rubbing treatment may be used. The in-plane slow axis is defined at 550 nm unless otherwise specified.

[0072] Examples of the method for applying the liquid crystal composition include curtain coating, dip coating, spin coating, print coating, spray coating, slot coating, roll coating, slide coating, blade coating, gravure coating, and wire bar coating.

[0073] Next, the formed coating film is subjected to an alignment treatment to align the liquid crystal compound in the coating film. The alignment treatment can be carried out by drying the coating film at room temperature or by heating the coating film. In the case of a thermotropic liquid crystal compound, the liquid crystal phase formed by the alignment treatment can generally be transitioned by a change in temperature or pressure. In the case of a lyotropic liquid crystal compound, the transition can also be caused by a composition ratio such as the amount of solvent. The conditions for heating the coating are not particularly limited, but the heating temperature is preferably 50 to 250° C., more preferably 50 to 150° C., and the heating time is preferably 10 seconds to 10 minutes. After heating the coating film, the coating film may be cooled, if necessary, before the curing treatment (light irradiation treatment) described below. The cooling temperature is preferably 20 to 200°C, and more preferably 30 to 150°C.

[0074] Next, the coating film in which the liquid crystal compound is aligned is subjected to a curing treatment. The method of hardening the coating film in which the liquid crystal compound is aligned is not particularly limited, and examples thereof include light irradiation and heat treatment. Among these, from the viewpoint of manufacturability, light irradiation is preferred, and ultraviolet irradiation is more preferred. The irradiation conditions for the light irradiation treatment are not particularly limited, but are preferably 50 to 1000 mJ / cm 2 is preferred. The atmosphere during the light irradiation treatment is not particularly limited, but a nitrogen atmosphere is preferred.

[0075] The optically anisotropic layer according to the second embodiment of the present invention is a layer in which the twist hybrid alignment of the liquid crystal compound is fixed, and in which the splay elastic constant K11 of the liquid crystal composition is greater than the bend elastic constant K33. Here, the magnitude relationship between the elastic constant K11 of the splay and the elastic constant K33 of the bend can be determined by whether the ratio (K11 / K33) of the elastic constant K11 of the splay to the elastic constant K33 of the bend is greater than 1, as explained in the first embodiment above. The ratio of the splay elastic constant K11 to the bend elastic constant K33 (K11 / K33) is a value measured according to the method described in the literature "Sen-i to Kogyo Vol. 42, No. 11 (1986), 449," as explained in the first embodiment above.

[0076] The optically anisotropic layer according to the second embodiment of the present invention has a liquid crystal composition used for forming the optically anisotropic layer having a splay elastic constant K11 that is greater than the bend elastic constant K33, and therefore has high linearity in the variation of the tilt angle, and when used as a circular polarizer in an organic EL display device, can suppress color change in the front direction and oblique directions. Although the details of the reason for this are not yet clear, the present inventors speculate that it is due to the following reasons. In the second embodiment of the present invention, since the splay elastic constant K11 of the liquid crystal composition is larger than the bend elastic constant K33, when the twist hybrid alignment is adopted, the liquid crystal composition can be energetically stabilized in a state in which the amount of bend distortion is larger than the amount of splay distortion. That is, in the second embodiment of the present invention, since the state in which the amount of bend distortion is large is advantageous for linearity, the linearity of the variation of the tilt angle is high, and it is considered that the color change in the front direction and the oblique direction can be suppressed when the liquid crystal composition is used as a circular polarizer in an organic EL display device.

[0077] In the optically anisotropic layer according to the second embodiment of the present invention, the ratio (K11 / K33) of the splay elastic constant K11 to the bend elastic constant K33 of the liquid crystal composition is preferably 1.0 or more, more preferably 1.1 or more. There is no particular upper limit, but it is usually preferably 10 or less.

[0078] The liquid crystal composition used for forming the optically anisotropic layer according to the second aspect of the present invention is not particularly limited as long as the splay elastic constant K11 of the liquid crystal composition is larger than the bend elastic constant K33, and for example, a composition containing a surfactant, a chiral agent, a polymerization initiator, a crosslinking agent and other additives described in the liquid crystal composition according to the first aspect of the present invention, in addition to a conventionally known liquid crystal compound, can be used. Here, the liquid crystal compound contained in the liquid crystal composition used for forming the optically anisotropic layer according to the second aspect of the present invention may be a liquid crystal compound having forward wavelength dispersion or a liquid crystal compound having reverse wavelength dispersion, but if it is a liquid crystal compound having forward wavelength dispersion, it is preferable in terms of reducing the manufacturing cost of the optical film and improving the durability. The method for producing the optically anisotropic layer according to the second embodiment of the present invention is not particularly limited, and may be the same as the method for producing the optically anisotropic layer according to the first embodiment of the present invention described above.

[0079] The transmittance of the optically anisotropic layer of the present invention in the visible light region is not particularly limited, but from the viewpoint of application to various optical uses, it is preferably 60% or more, more preferably 80% or more, and more preferably 90% or more. The upper limit is not particularly limited, but it can be less than 100%. In addition, the optically anisotropic layer of the present invention is preferably substantially free of dichroic substances from the viewpoint of application to various optical uses. Substantially free of dichroic substances means that the content of the dichroic substances is 0.1% by mass or less, preferably 0.05% by mass or less, based on the total mass of the optically anisotropic layer. The lower limit is not particularly limited, but may be 0% by mass.

[0080] [Optical film] The optical film of the present invention is an optical film having the optically anisotropic layer of the present invention described above. The optical film of the present invention preferably has the optically anisotropic layer of the present invention as a first optically anisotropic layer, and has a second optically anisotropic layer different from the first optically anisotropic layer. Furthermore, the optical film of the present invention may have other layer configurations, such as a support and an alignment layer. The second optically anisotropic layer, the support and the alignment layer, which are optional composition configurations in the optical film of the present invention, will be described in detail below.

[0081] [Second Optically Anisotropic Layer] The second optically anisotropic layer may be a layer formed using a liquid crystal compound, or may be a layer other than the above. The layer formed by using a liquid crystal compound includes a layer formed by fixing a liquid crystal compound in a predetermined alignment state. The alignment state that the liquid crystal compound can take includes, for example, a twisted alignment, a homogeneous alignment, a homeotropic alignment, a hybrid alignment, an inclined alignment, and a twisted hybrid alignment. As the layer other than the layer formed using the liquid crystal compound, for example, a stretched resin film can be mentioned. Among these, in terms of superior effects of the present invention, the second optically anisotropic layer is preferably a layer in which a second liquid crystal compound having a homogeneous orientation, a hybrid orientation, or an inclined orientation is fixed, or a layer in which a second liquid crystal compound having a twisted orientation or a twist hybrid orientation is fixed.

[0082] When the second optically anisotropic layer is a layer in which a twisted second liquid crystal compound is fixed, the twist direction of the first liquid crystal compound in the first optically anisotropic layer and the twist direction of the second liquid crystal compound in the second optically anisotropic layer may be the same direction or opposite directions. In particular, in terms of better effects of the present invention, it is preferable that the twist direction of the first liquid crystal compound in the first optically anisotropic layer and the twist direction of the second liquid crystal compound in the second optically anisotropic layer are opposite directions.

[0083] In this specification, homogeneous orientation refers to a state in which the molecular axis of a liquid crystal compound (for example, the long axis in the case of a rod-shaped liquid crystal compound) is aligned horizontally and in the same direction relative to the surface of the optically anisotropic layer (optically uniaxial). Here, horizontal does not necessarily mean strictly horizontal, but means an orientation in which the average molecular axis of the liquid crystal compound in the optically anisotropic layer forms an inclination angle of less than 5° with the surface of the optically anisotropic layer. In addition, the same orientation does not require the orientation to be strictly the same, but rather means that when the orientations of the in-plane slow axes are measured at any 20 positions within the plane, the maximum difference between the slow axis orientations among the in-plane slow axis orientations at the 20 positions (the difference between the two in-plane slow axis orientations with the largest difference among the 20 in-plane slow axis orientations) is less than 5°. In addition, when the liquid crystal compound is homogeneously oriented, the maximum difference between any one of the 20 in-plane slow axis orientations on one surface of the optically anisotropic layer and any one of the 20 in-plane slow axis orientations on the other surface is less than 5°.

[0084] The second liquid crystal compound used to form the second optically anisotropic layer may be the rod-shaped liquid crystal compound and discotic liquid crystal compound described above in relation to the liquid crystal composition according to the first embodiment of the present invention. The second liquid crystal compound may be a liquid crystal compound with forward wavelength dispersion or a liquid crystal compound with reverse wavelength dispersion. When the second liquid crystal compound is a liquid crystal compound with forward wavelength dispersion, the production cost of the optical film is reduced and durability is improved, which is preferable.

[0085] [Support] The support is preferably a transparent support, which means a support having a visible light transmittance of 60% or more, preferably 80% or more, and more preferably 90% or more.

[0086] The support may be a long support (long support). The length of the long support in the longitudinal direction is not particularly limited, but a support of 10 m or more is preferable, and from the viewpoint of productivity, a support of 100 m or more is preferable. The length in the longitudinal direction is not particularly limited, and is often 10,000 m or less. The width of the long support is not particularly limited, but is often 150 to 3000 mm, preferably 300 to 2000 mm.

[0087] The retardation value (Rth(550)) in the thickness direction of the support at a wavelength of 550 nm is not particularly limited, but is preferably from −110 to 110 nm, and more preferably from −80 to 80 nm. The in-plane retardation value (Re(550)) of the support at a wavelength of 550 nm is not particularly limited, but is preferably from 0 to 50 nm, more preferably from 0 to 30 nm, and further preferably from 0 to 10 nm.

[0088] The material for forming the support is preferably a polymer that is excellent in optical performance transparency, mechanical strength, thermal stability, moisture barrier properties, isotropy, and the like. Examples of polymer films that can be used as the support include cellulose acylate films (e.g., cellulose triacetate film, cellulose diacetate film, cellulose acetate butyrate film, and cellulose acetate propionate film), polyolefin films such as polyethylene and polypropylene, polyester films such as polyethylene terephthalate and polyethylene naphthalate, polyethersulfone films, polyacrylic films such as polymethyl methacrylate, polyurethane films, polycarbonate films, polysulfone films, polyether films, polymethylpentene films, polyether ketone films, (meth)acrylonitrile films, and films of polymers having an alicyclic structure (norbornene-based resins (Arton: product name, manufactured by JSR Corporation, amorphous polyolefins (Zeonex: product name, manufactured by Zeon Corporation))). Among these, triacetyl cellulose, polyethylene terephthalate, or a polymer having an alicyclic structure is preferable as the material for the polymer film.

[0089] The support may contain various additives (for example, an optical anisotropy adjusting agent, a wavelength dispersion adjusting agent, fine particles, a plasticizer, an ultraviolet protection agent, a deterioration inhibitor, and a release agent).

[0090] The thickness of the support is not particularly limited, but is preferably from 10 to 200 μm, more preferably from 10 to 100 μm, and even more preferably from 20 to 90 μm. The support may also be made up of a laminate of multiple sheets. The support may be subjected to a surface treatment (e.g., glow discharge treatment, corona discharge treatment, ultraviolet (UV) treatment, and flame treatment) on the surface thereof to improve adhesion with a layer disposed thereon. In addition, an adhesive layer (undercoat layer) may be provided on the support. The support may be a so-called temporary support.

[0091] In addition, the surface of the support may be directly subjected to rubbing treatment. In other words, a support that has been subjected to rubbing treatment may be used. The direction of the rubbing treatment is not particularly limited, and an optimal direction is appropriately selected depending on the direction in which the liquid crystal compound is desired to be aligned. The rubbing treatment can be a treatment method that is widely used as a liquid crystal alignment treatment process for LCDs (liquid crystal displays), in which the surface of the support is rubbed in a certain direction with paper, gauze, felt, rubber, nylon fiber, polyester fiber, or the like to obtain alignment.

[0092] [Alignment film] The alignment layer can be formed by such means as rubbing an organic compound (preferably a polymer), oblique deposition of an inorganic compound, formation of a layer with microgrooves, or deposition of an organic compound (e.g., ω-tricosanoic acid, dioctadecylmethylammonium chloride, methyl stearate) by the Langmuir-Blodgett technique (LB film). Furthermore, an alignment film is also known that exhibits an alignment function when an electric field is applied, a magnetic field is applied, or light (preferably polarized light) is irradiated. The alignment film is preferably formed by a rubbing treatment of a polymer.

[0093] [Circular polarizing plate] The circular polarizing plate of the present invention is a circular polarizing plate obtained by laminating the above-mentioned optical film of the present invention and a polarizer. Among them, a circular polarizing plate in which a first optically anisotropic layer, a second optically anisotropic layer, and a polarizer are laminated in this order is preferred. The polarizer may be any member capable of converting natural light into a specific linearly polarized light, and an example of the polarizer is an absorptive polarizer. The type of polarizer is not particularly limited, and any commonly used polarizer can be used, such as an iodine-based polarizer, a dye-based polarizer using a dichroic dye, and a polyene-based polarizer. Iodine-based polarizers and dye-based polarizers are generally produced by adsorbing iodine or a dichroic dye to polyvinyl alcohol and stretching it. A protective film may be disposed on one or both sides of the polarizer.

[0094] The method for producing the circularly polarizing plate is not particularly limited, and any known method can be used. For example, the optical film and the polarizer may be bonded to each other via an adhesive layer.

[0095] [Organic EL display device] The organic EL display device of the present invention is an organic EL display device having the above-mentioned circular polarizer of the present invention. Typically, the circular polarizing plate is provided on an organic EL display panel of an organic EL display device. For example, the organic EL display device includes at least an organic EL display panel, an optical film, and a polarizer. The organic EL display device may further have a protective film on the polarizer.

[0096] An organic EL display panel is a member in which a light-emitting layer or a plurality of organic compound thin films including a light-emitting layer are formed between a pair of electrodes, an anode and a cathode, and may have a hole injection layer, a hole transport layer, an electron injection layer, an electron transport layer, a protective layer, etc. in addition to the light-emitting layer, and each of these layers may have other functions. Various materials can be used to form each layer.

[0097] The optical film of the present invention may be applied to other display devices besides the above-mentioned organic EL display devices, such as liquid crystal display devices. The optical film of the present invention may be used for other purposes besides the use for preventing external light reflection, such as an optical compensation layer for a liquid crystal display device. The optical film of the present invention can be used in various applications as a λ / 2 plate and a λ / 4 plate. EXAMPLES

[0098] The features of the present invention will be described in more detail below with reference to examples and comparative examples. The materials, reagents, amounts used, amounts of substances, ratios, treatment contents, treatment procedures, etc. shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be interpreted as being limited by the specific examples shown below.

[0099] [Preparation of Support] Support 5 described in Table 1 of JP 2014-209219 A was prepared according to the same procedure as above to obtain Support 1. The Rth(550) of the obtained Support 1 was 0 nm.

[0100] [Example 1] According to the procedures described in paragraphs 0116 to 0119 of JP2014-209219A, the support 1 prepared above was subjected to an alkali saponification treatment and an alignment film was formed.

[0101] [Formation of Optically Anisotropic Layer] The alignment film thus prepared was continuously subjected to a rubbing treatment, in which the longitudinal direction of the long film was parallel to the conveying direction, and the rubbing direction was adjusted to be −14° with respect to the longitudinal direction of the film. The angle of the rubbing direction is expressed by observing the support from the side on which the optically anisotropic layer B described later is laminated, with the longitudinal direction of the support taken as the reference 0°, and a positive angle value in the counterclockwise direction and a negative angle value in the clockwise direction.

[0102] Next, a liquid crystal composition (RLC(1)) containing a rod-shaped liquid crystal compound shown in Table 1 below was applied onto the alignment film prepared above using a wire bar #3. The film transport speed (V) was 5 m / min. Thereafter, the resulting coating film was heated with hot air at 80°C for 1.5 minutes to dry the solvent in the composition and to mature the alignment of the rod-shaped liquid crystal compound. Next, the coating film was irradiated with ultraviolet (UV) rays (500 mJ / cm2) at 75°C in a nitrogen environment. 2 ) was carried out to fix the alignment of the rod-like liquid crystal compound, thereby obtaining an optically anisotropic layer RLC(1).

[0103] [Examples 2 to 14, Comparative Examples 1 to 5] Optically anisotropic layers RLC(2) to (19) and DLC(1) to (2) were produced in the same manner as in Example 1, except that the rubbing direction and the liquid crystal composition were changed as shown in Tables 1 and 2 below during the production of the optically anisotropic layers. The optically anisotropic layer RLC(19) and the optically anisotropic layer DLC(2) are optically anisotropic layers used as the second optically anisotropic layers in Example 15 and Example 22 described later, respectively.

[0104] Tables 1 and 2 below show the compositions of the liquid crystal compositions used in the examples and comparative examples. The solid content of each liquid crystal composition was adjusted using 2-butanone (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) as a solvent. The structures of compounds 1 to 17 in Tables 1 and 2 are shown below.

[0105] Compound 1 (hereinafter, this refers to a mixture of compounds, and the values ​​(%) indicate the content (mass%) of each compound in the mixture.) [ka]

[0106] compound 2 [ka]

[0107] compound 3

change

[0108] Compound 4

change

[0109] Compound 5

change

[0110] Compound 6

change

[0111] Compound 7

change

[0112] Compound 8

change

[0113] Compound 9

change

[0114] Compound 10

change

[0115] Compound 11

change

[0116] Compound 12 2.5 g of FAAC-6 (manufactured by Unimatec Co., Ltd.) and 2.5 g of acrylic acid (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were polymerized by a conventional radical polymerization method to obtain compound 12 having the following structure. [ka]

[0117] compound 13 [ka]

[0118] compound 14 [ka]

[0119] compound 15 [ka]

[0120] compound 16 [ka]

[0121] compound 17 [ka]

[0122] [evaluation] The evaluation results of Examples 1 to 14 and Comparative Examples 1 to 5 are shown in Tables 1 and 2 below. The tilt angle (upward tilt angle) on the air interface side, the tilt angle (downward tilt angle) on the alignment film side, the twist angle and Δnd of each of the optically anisotropic layers prepared were measured using AxoScan by Axometrics.

[0123] <Elastic constant> The elastic constant of each liquid crystal composition at 75° C. was measured by a light scattering method, and the elastic constant was evaluated according to the following indexes. 2:K11 / K33 is 1 or greater. 1:K11 / K33 is less than 1.

[0124] <Linarity> For each optically anisotropic layer, optical measurements were carried out using an AxoScan from Axometrics under conditions of 550 nm, azimuth angle of 0 to 180°, and polar angle of -40 to 40°. First, a fitting parameter a, which represents the linearity of the tilt angle, was determined so as to best explain the retardation of the optically anisotropic layer at each angle. Specifically, the Mueller matrix measured by Axoscan was used as the target function, and each variable was changed to perform optimization so as to minimize the error between the Mueller matrix calculated by polarization optics calculation from the input optical structure and the measured Mueller matrix. The fitting parameter a, expressed by the following formula, was determined, and linearity was evaluated using the following index. (formula) θ=θ2+(θ1-θ2)×(a*z+(1-a)*z 2 ) θ: Tilt angle at position z z: Position from the bottom interface (the bottom interface is 0, the top interface is 1) θ1: Tilt angle at the upper interface θ2: Tilt angle at the lower interface (index) 4: a is greater than or equal to 0.75 and less than 1.25 3: a is greater than or equal to 0.50 and less than 1.50, and does not fall under “4”. 2: a is greater than or equal to 0.25 and less than 1.75, and does not fall under “4” or “3.” 1: Does not fall under "4", "3" or "2".

[0125] [Table 1]

[0126] [Table 2]

[0127] From the results shown in Tables 1 and 2 above, it was found that when a compound corresponding to compound I or compound II is not blended and the splay elastic constant K11 of the liquid crystal composition is smaller than the bend elastic constant K33, the linearity of the change in tilt angle is poor (Comparative Examples 1 to 5). In contrast, when a compound corresponding to Compound I or Compound II was blended, it was found that the linearity of the variation of the tilt angle was increased (Examples 1 to 13). In particular, a comparison between Example 1 and Example 9 revealed that when the splay elastic constant K11 of the liquid crystal composition was larger than the bend elastic constant K33, the linearity of the variation of the tilt angle was higher. In addition, it was found that the linearity of the change in tilt angle becomes high when the splay elastic constant K11 of the liquid crystal composition is larger than the bend elastic constant K33, even if a compound corresponding to compound I or compound II is not added (Example 14).

[0128] [Example 15] [Preparation of Polarizer] A polyvinyl alcohol film having a thickness of 80 μm was dyed by immersing it in an aqueous iodine solution having an iodine concentration of 0.05% by mass at 30° C. for 60 seconds. Next, the obtained film was immersed in an aqueous boric acid solution having a boric acid concentration of 4% by mass for 60 seconds, during which it was longitudinally stretched to 5 times its original length, and then dried at 50°C for 4 minutes to obtain a polarizer having a thickness of 20 μm.

[0129] [Preparation of Polarizer Protective Film] A commercially available cellulose acylate film "TD80UL" (manufactured by Fujifilm Corporation) was prepared and immersed in a 1.5 mol / L aqueous sodium hydroxide solution at 55°C, and then the sodium hydroxide was thoroughly washed off with water. Thereafter, the obtained film was immersed in a 0.005 mol / liter dilute sulfuric acid aqueous solution at 35° C. for 1 minute, and then immersed in water to thoroughly wash away the dilute sulfuric acid aqueous solution. Finally, the obtained film was thoroughly dried at 120° C. to prepare a polarizer protective film having a saponification treatment on the surface.

[0130] [Preparation of Circular Polarizing Plate] <Preparation of optical film> The optically anisotropic layer RLC(19) prepared by the above method was not subjected to a rubbing treatment, and the liquid crystal composition (RLC(1)) shown in Table 1 above was applied onto the optically anisotropic layer RLC(19) using a wire bar #3. The film was conveyed at a speed (V) of 5 m / min. The resulting coating was then heated with hot air at 110°C for 2 minutes to dry the solvent in the composition and to mature the alignment of the liquid crystal compound. Next, the coating was irradiated with UV light (500 mJ / cm2) at 80°C in a nitrogen environment. 2 ) was performed to fix the alignment of the liquid crystal compound, forming an optically anisotropic layer RLC(1), and producing an optical film. The in-plane slow axis of the surface of the optically anisotropic layer RLC(1) on the optically anisotropic layer RLC(19) side was parallel to the in-plane slow axis of the surface of the optically anisotropic layer RLC(19) on the optically anisotropic layer RLC(1). The above-mentioned polarizer and polarizer protective film were continuously bonded to the exposed surface of the support of the prepared optical film using a polyvinyl alcohol-based adhesive to prepare a long circularly polarizing plate (P-1). That is, the circular polarizing plate (P-1) had a polarizer protective film, a polarizer, a support, an optically anisotropic layer RLC(19), and an optically anisotropic layer RLC(1) in this order.

[0131] [Examples 16 to 22 and Comparative Examples 6 to 8] Circularly polarizing plates (P-2) to (P-11) were produced in the same manner as in Example 15, except that the optical films were changed as shown in Table 3 below.

[0132] [Example 23 and Comparative Example 9] Using the liquid crystal compositions (RLC(20) and RLC(21)) shown in Table 4 below, optically anisotropic layers 1 and 2 were produced at the same time by one coating operation. Specifically, the liquid crystal composition was applied onto the same rubbed support as in Example 1, and heated for 60 seconds at 80° C. By this heating, the rod-shaped liquid crystal compound in the composition layer was aligned in a predetermined direction. Thereafter, the sample was irradiated with ultraviolet light (70 mJ / cm ) using a 365 nm LED lamp (manufactured by Acroedge Co., Ltd.) at 30°C under oxygen-containing air. 2 ). The resulting composition layer was then heated at 80° C. for 10 seconds. Thereafter, nitrogen purging was performed to adjust the oxygen concentration to 100 ppm by volume, and ultraviolet light was irradiated (500 mJ / cm 2 ) using a metal halide lamp (manufactured by Eye Graphics Co., Ltd.) at 80° C. 2 ) to form an optically anisotropic layer in which the alignment state of the liquid crystal compound was fixed.

[0133] [Example 24 and Comparative Example 10] Circularly polarizing plates (P-12) and (P-13) were produced in the same manner as in Example 15, except that the optical film was changed as shown in Table 5 below.

[0134] [evaluation] <Implementation on an OLED display device and evaluation of display performance> (Mounting to a display device) A Samsung GALAXY SII equipped with an organic EL display panel was disassembled, the circular polarizing plate was peeled off, and the circular polarizing plates prepared in Examples 15 to 22 and 24, and Comparative Examples 6 to 8 and 10 were attached to the display device with the polarizer protective film positioned on the outside.

[0135] The organic EL display device thus fabricated was evaluated for black coloring when viewed from an oblique angle. The display device was made to display black, and was observed from a polar angle of 60 degrees, and was evaluated according to the following criteria. The results are summarized in Tables 3 and 5 below. 4: No visible color change when compared to the front. (Acceptable) 3: Coloring is visible compared to the front, but very slight (acceptable). 2: Slight color fading is visible compared to the front. (Acceptable) 1: Compared to the front, coloring is visible and there is a lot of reflected light, which is unacceptable.

[0136] [Table 3]

[0137] [Table 4]

[0138] [Table 5]

[0139] As shown in Tables 3 and 5 above, it was found that when the circular polarizing plates produced in the Examples were used in organic EL display devices, color changes in the front direction and oblique directions could be suppressed (Examples 15 to 22 and 24). In the above examples, the first optically anisotropic layer was manufactured using a liquid crystal compound that forms a right-handed twist structure. However, even when a liquid crystal compound that forms a left-handed twist structure was used, a circular polarizing plate exhibiting the desired characteristics could be formed by adjusting the relationship between the absorption axis of the polarizer, the in-plane slow axis of the first optically anisotropic layer, and the in-plane slow axis of the second optically anisotropic layer, as described above. [Explanation of symbols]

[0140] 10 Optically anisotropic layer 10A One surface of the optically anisotropic layer 10B Other surface of optically anisotropic layer LC liquid crystal compound LCxy: Projection component of the optically anisotropic layer of liquid crystal compound

Claims

1. An optically anisotropic layer formed using a liquid crystal composition containing a liquid crystal compound, the optically anisotropic layer is a layer in which the alignment state of the liquid crystal compound is fixed, the alignment state is an alignment state in which the liquid crystal compound is twisted and the angle of the optical axis of the liquid crystal compound with respect to the surface of the optically anisotropic layer changes continuously along the thickness direction, The liquid crystal composition contains at least one of a compound represented by the following formula (I) and a compound represented by the following formula (II), and a rod-shaped liquid crystal compound having a polymerizable group, which does not correspond to either of the following formulas (I) and (II): The optically anisotropic layer, wherein the splay elastic constant K11 of the liquid crystal composition is greater than the bend elastic constant K33. 【Chemistry 1】 Here, in the formula (I), P １ and P ２ each independently represents a hydrogen atom or a substituent. S １ and S ２ each independently represents a single bond or a divalent linking group. A １ , A ２ , A ３ and A ４ each independently represents a non-aromatic ring, an aromatic ring, or an aromatic heterocyclic ring, which may have a substituent. １ If there are multiple A １ may be the same or different, A ４ If there are multiple A ４ may be the same or different. Y １ and Y ２ each independently represents -O-, -S-, or -OCH ２ --, --CH ２ O-, -CH ２ CH ２ -, -CO-, -COO-, -OCO-, -CO-S-, -S-CO-, -O-CO-O-, -CO-NH-, -NH-CO-, -SCH ２ --, --CH ２ S-, -CF ２ O-, -OCF ２ -, -CF ２ S-, -SCF ２ represents -, -CH=CH-COO-, -CH=CH-OCO-, -COO-CH=CH-, -OCO-CH=CH-, -CH=CH-, -N=N-, -CH=N-N=CH-, -CF=CF-, -C≡C-, or a single bond. １ If there are multiple Y １ may be the same or different, Y ２ If there are multiple Y ２ may be the same or different. m1 and m2 each independently represent an integer of 0 to 5. Z represents a linear or branched alkylene group having no aromatic substituent. ２ and A ３ and the number of atoms on the bond connecting them at the shortest distance is 3 or more, and one —CH ２ - or two or more non-adjacent -CH ２ - is -O-, -COO-, -OCO-, -OCOO-, -NRCO-, -CONR-, -NRCOO-, -OCONR-, -CO-, -S-, -SO ２ -, -NR-, -NRSO ２ - or -SO ２ It may be substituted with NR-, where R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. 【Chemistry 2】 Here, in the formula (II), P ３ and P ４ each independently represents a hydrogen atom or a substituent. S ３ and S ４ each independently represents a single bond or a divalent linking group. A ５ and A ６ each independently represents a non-aromatic ring, an aromatic ring, or an aromatic heterocyclic ring, which may have a substituent. ５ If there are multiple A ５ may be the same or different, A ６ If there are multiple A ６ may be the same or different. Y ３ and Y ４ each independently represents -O-, -S-, or -OCH ２ --, --CH ２ O-, -CH ２ CH ２ -, -CO-, -COO-, -OCO-, -CO-S-, -S-CO-, -O-CO-O-, -CO-NH-, -NH-CO-, -SCH ２ --, --CH ２ S-, -CF ２ O-, -OCF ２ -, -CF ２ S-, -SCF ２ -, -CH=CH-COO-, -CH=CH-OCO-, -COO-CH=CH-, -OCO-CH=CH-, -COO-CH ２ CH ２ --, --OCO-CH ２ CH ２ --, --CH ２ CH ２ -COO-, -CH ２ CH ２ -OCO-, -COO-CH ２ --, --OCO-CH ２ --, --CH ２ -COO-, -CH ２ represents -OCO-, -CH=CH-, -N=N-, -CH=N-N=CH-, -CF=CF-, -C≡C-, or a single bond. ３ If there are multiple Y ３ may be the same or different, Y ４ If there are multiple Y ４ may be the same or different. m3 and m4 each independently represent an integer of 1 to 5. B represents any one of the groups represented by the following formulae (B-1) to (B-11), which may have a substituent. 【Chemistry 3】 However, the carbon atoms in the formulae (B-1) to (B-11) may be substituted with nitrogen atoms, oxygen atoms or sulfur atoms. X in the formulae (B-4) to (B-8), (B-10) and (B-11) represents a nitrogen atom, an oxygen atom or a sulfur atom, the two X in the formula (B-5) may each be the same atom or different atoms, and the two X in the formula (B-6) may each be the same atom or different atoms. When B is a group represented by the formula (B-11), Y bonded to B is ３ and Y ４ Each of them represents a single bond.

2. 2. The optically anisotropic layer according to claim 1, wherein the total content of the compound represented by formula (I) and the compound represented by formula (II) is 50% by mass or less based on the mass of the rod-like liquid crystal compound.

3. 3. The optically anisotropic layer according to claim 1, wherein the liquid crystal composition contains a liquid crystal compound having a bend elastic constant K33 greater than the splay elastic constant K11, and a liquid crystal compound having a bend elastic constant K33 smaller than the splay elastic constant K11.

4. An optically anisotropic layer formed using a liquid crystal composition containing a liquid crystal compound, the optically anisotropic layer is a layer in which the alignment state of the liquid crystal compound is fixed, the alignment state is an alignment state in which the liquid crystal compound is twisted and the angle of the optical axis of the liquid crystal compound with respect to the surface of the optically anisotropic layer changes continuously along the thickness direction, The optically anisotropic layer, wherein the splay elastic constant K11 of the liquid crystal composition is greater than the bend elastic constant K33.

5. An optical film having the optically anisotropic layer according to any one of claims 1 to 4.

6. A first optically anisotropic layer and a second optically anisotropic layer are provided. The optical film according to claim 5, wherein the first optically anisotropic layer is the optically anisotropic layer according to any one of claims 1 to 4.

7. A circularly polarizing plate comprising the optical film according to claim 5 or 6 laminated with a polarizer.

8. An organic electroluminescence display device comprising the circular polarizer according to claim 7 .

Images