JP2008185814A - Liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device with which a high quality image with a wide viewing angle is displayed. <P>SOLUTION: The liquid crystal display device has: a liquid crystal layer in which liquid crystal molecules are aligned between substrates with a twist angle of 45° or less and nearly in parallel to substrate surfaces in a state with no voltage applied thereto, and the liquid crystal molecules are aligned in a direction normal to the substrate surfaces in a state with a voltage applied thereto; first and second polarizing layers disposed so as to interpose the liquid crystal layer in between and perpendicularly intersecting each other; and a first retardation layer (16) and a second retardation layer disposed between the first polarizing layer and/or the second polarizing layer and the liquid crystal layer, and is characterized in that the first retardation layer is formed by hardening a liquid crystal composition containing a rod shaped liquid crystal compound, and the second retardation layer has its in-plane slow axis being parallel to, or vertical to, an absorption axis of the first or second polarizing layer disposed in the vicinity thereof, and the retardation Rth(550) at 550 nm wavelength in the thickness direction of the second retardation layer satisfies formula (1) -300 nm<Rth(550)<50 nm. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a liquid crystal display device of, for example, an ECB mode, which is aligned substantially parallel (homogeneous alignment) to a substrate surface when no voltage is applied and is aligned substantially perpendicular (homotropic alignment) to the substrate surface when a voltage is applied The present invention relates to an optical compensation method for improving viewing angle characteristics.

  Various modes have been proposed for liquid crystal display devices. As one of them, a so-called ECB mode liquid crystal display device using an electrically controlled birefringence effect is known. In an ECB mode liquid crystal display device, a liquid crystal cell is usually sandwiched between two crossed Nicols polarizing plates, an electric field is applied to the liquid crystal cell to change the birefringence of the liquid crystal cell, and the amount of light passing through the liquid crystal cell is reduced. It is a method of adjusting and displaying. As an example, there is a normally black display system in which a liquid crystal layer is homogeneously aligned when no voltage is applied to display black, and the alignment is controlled to display white when a voltage is applied.

Since the ECB mode liquid crystal display device does not use the twisted alignment of liquid crystal, it has an advantage of high response speed. However, in an ECB mode liquid crystal display device in which the liquid crystal layer is homogeneously aligned when no voltage is applied, a shift in display color and a decrease in contrast are observed in an oblique direction, and an increase in viewing angle is desired. For example, Patent Document 1 discloses that a liquid crystal layer includes a uniaxial medium having positive optical anisotropy having an optical axis in a direction perpendicular to a substrate surface in order to reduce a change in display color depending on a viewing angle. An ECB mode liquid crystal which is arranged between the polarizer and the product of the refractive index anisotropy of the uniaxial medium and the thickness of the uniaxial medium differs according to the difference in display color determined for each display pixel. Display devices have been proposed. Patent Document 2 proposes that an optical compensation means is disposed between the liquid crystal cell and the polarizing plate to cancel the retardation of the liquid crystal cell when no voltage is applied (at the time of homogeneous alignment). . Patent Document 2 can use a homogeneously aligned liquid crystal cell whose orientation is controlled by a rubbing axis in a direction perpendicular to the rubbing axis for controlling the alignment of liquid crystalline molecules in the liquid crystal as an optical compensation means. And that a birefringent film may be used.
However, depending on applications such as for large screens, it is necessary to display high-contrast and high-quality images over a wider viewing angle, which is not satisfactory with the above technique.
Japanese Patent Laid-Open No. 03-9319 Japanese Patent Laid-Open No. 04-40427

  The present invention provides a liquid crystal display device, particularly an ECB mode liquid crystal display device, that uses a liquid crystal cell that is homogeneously aligned when no voltage is applied and can display a high-contrast, high-quality image over a wide viewing angle. Let it be an issue.

  The polarizing plate of a liquid crystal display device usually has a film for protecting it on the surface of the polarizing film. Commercially available cellulose acylate films and the like are frequently used as the protective film, but these films exhibit a certain degree of retardation. The inventor does not take into account the retardation of such other members, and the technique described in the above-mentioned patent document does not exhibit a sufficient effect depending on the optical characteristics of other members such as a protective film. I found. Furthermore, as a result of repeated studies based on this knowledge, by arranging a second retardation layer that satisfies predetermined optical characteristics together with a first retardation layer that cancels the birefringence of the liquid crystal cell, for example, polarization It has been found that the above problem can be solved by arranging the protective film on the plate, and the present invention has been completed.

Means for solving the above-mentioned problems are as follows.
[1] First and second substrates that are arranged to face each other and at least one of them has a transparent electrode; liquid crystal molecules are twisted between the first and second substrates without applying a voltage between the substrates. A liquid crystal layer having an angle of 45 ° or less and oriented substantially parallel to the substrate surface, and in which a liquid crystal molecule is oriented in a normal direction of the substrate surface when a voltage is applied; and polarized light that is disposed across the liquid crystal layer and orthogonal to each other First and second polarizing layers having an axis; a first retardation layer between the first and / or second polarizing layer and the liquid crystal layer; and the first and / or second polarizing layer A second retardation layer between the liquid crystal layer and the liquid crystal layer,
The first retardation layer is a layer formed by curing a liquid crystal composition containing a rod-like liquid crystal compound, and the in-plane slow axis of the layer is a liquid crystal in the liquid crystal layer in a state in which no voltage is applied. In the direction perpendicular to the average orientation direction of the major axis of the molecule,
The in-plane slow axis of the second retardation layer is parallel or orthogonal to the absorption axis of the first or second polarizing layer disposed closer to the layer, and the thickness direction of the layer at a wavelength of 550 nm The retardation Rth (550) of the liquid crystal display device satisfies the following formula (1):
(1) −200 nm <Rth (550) <0 nm.
[2] The liquid crystal display device of [1], wherein Rth (550) of the second retardation layer satisfies the following formula (1) ′:
(1) ′ −150 nm ≦ Rth (550) ≦ −70 nm.
[3] The in-plane retardation Re of the first retardation layer and the effective retardation in the panel normal direction of the liquid crystal layer during black display are substantially equal at a wavelength of 550 nm [1] or [ 2] Liquid crystal display device.
[4] The in-plane slow axis of the second retardation layer is substantially parallel to the absorption axis of the first or second polarizing layer disposed closer to the layer, and the wavelength of the layer is 550 nm. The in-plane retardation Re (550) in the above satisfies the following formula (2): The liquid crystal display device of any one of [1] to [3]:
(2) 0 nm ≦ Re (550) ≦ 130 nm.
[5] The first retardation phase is formed by curing a curable composition containing at least one kind of rod-like liquid crystal compound having two or more photopolymerizable functional groups [1] ]-[4] liquid crystal display device.
[6] The second retardation layer contains cellulose acylate having a substituent having a polarizability anisotropy Δα represented by the following formula (A) of 2.5 × 10 ⁻²⁴ cm ⁻³ or more. The liquid crystal display device according to any one of [1] to [5], comprising a film that performs:
Δα = αx− (αy + αz) / 2 (A)
In the formula, αx, αy, and αz are eigenvalues obtained after diagonalizing the polarizability tensor and satisfy αx ≧ αy ≧ αz.
[7] The second retardation layer is formed by curing a curable composition containing at least one rod-like liquid crystal compound having two or more photopolymerizable functional groups [1] ]-[6] liquid crystal display device.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in detail.
In the present specification, “to” is used to mean that the numerical values described before and after it are included as a lower limit value and an upper limit value.
In the present specification, Re (λ) and Rth (λ) represent in-plane retardation and retardation in the thickness direction at the wavelength λ, respectively. Re (λ) is measured by making light having a wavelength of λ nm incident in the normal direction of the film in KOBRA 21ADH or WR (manufactured by Oji Scientific Instruments).
When the film to be measured is represented by a uniaxial or biaxial refractive index ellipsoid, Rth (λ) is calculated by the following method.
Rth (λ) is Re (λ), with the in-plane slow axis (determined by KOBRA 21ADH or WR) as the tilt axis (rotation axis) (in the absence of the slow axis, any in-plane value) The light of wavelength λ nm is incident from each of the inclined directions in steps of 10 degrees from the normal direction to 50 degrees on one side with respect to the film normal direction (with the direction of the rotation axis as the rotation axis). KOBRA 21ADH or WR is calculated based on the measured retardation value, the assumed value of the average refractive index, and the input film thickness value.
In the above case, in the case of a film having a direction in which the retardation value is zero at a certain tilt angle with the in-plane slow axis from the normal direction as the rotation axis, retardation at a tilt angle larger than the tilt angle. The value is calculated by KOBRA 21ADH or WR after changing its sign to negative.
In addition, the retardation value is measured from the two inclined directions, with the slow axis as the tilt axis (rotation axis) (in the absence of the slow axis, the arbitrary direction in the film plane is the rotation axis), Based on the value, the assumed value of the average refractive index, and the input film thickness value, Rth can also be calculated from the following equations (1) and (2).

注記：
上記のＲｅ（θ）は法線方向から角度θ傾斜した方向におけるレターデーション値をあらわす。
式中、ｎｘは面内における遅相軸方向の屈折率を表し、ｎｙは面内においてｎｘに直交する方向の屈折率を表し、ｎｚはｎｘ及びｎｙに直交する方向の屈折率を表し、ｄは層の厚みである。

Note:
The above Re (θ) represents a retardation value in a direction inclined by an angle θ from the normal direction.
In the formula, nx represents the refractive index in the slow axis direction in the plane, ny represents the refractive index in the direction perpendicular to nx in the plane, nz represents the refractive index in the direction perpendicular to nx and ny, and d Is the thickness of the layer.

In the case where the film to be measured cannot be expressed by a uniaxial or biaxial refractive index ellipsoid, that is, a film having no so-called optical axis, Rth (λ) is calculated by the following method.
Rth (λ) is the above-mentioned Re (λ), and the in-plane slow axis (determined by KOBRA 21ADH or WR) is the tilt axis (rotation axis) from −50 degrees to +50 degrees with respect to the film normal direction. The light of wavelength λ nm is incident from each inclined direction in 10 degree steps and measured at 11 points. Based on the measured retardation value, the assumed average refractive index, and the input film thickness value, KOBRA 21ADH or WR is calculated.
In the above measurement, the assumed value of the average refractive index may be a value in a polymer handbook (John Wiley & Sons, Inc.) or a catalog of various optical films. Those whose average refractive index is not known can be measured with an Abbe refractometer. Examples of the average refractive index values of main optical films are given below:
Cellulose acylate (1.48), cycloolefin polymer (1.52), polycarbonate (1.59), polymethyl methacrylate (1.49), and polystyrene (1.59).
By inputting these assumed values of average refractive index and film thickness, KOBRA 21ADH or WR calculates nx, ny, and nz. Nz = (nx−nz) / (nx−ny) is further calculated from the calculated nx, ny, and nz.

Hereinafter, the liquid crystal display device of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic cross-sectional view of an example of the liquid crystal display device of the present invention. Note that FIG. 1 is a schematic diagram, and the relative relationship such as the thickness of the layers and the shape and size of the liquid crystalline molecules in each layer are not necessarily consistent with the actual ones. Absent. The same applies to the drawings described later.
The liquid crystal display device shown in FIG. 1 includes an ECB mode liquid crystal cell 18 and a pair of an upper polarizing plate 20a and a lower polarizing plate 20b which are arranged with the liquid crystal cell interposed therebetween. The polarizing plates 20a and 20b have polarizing films 12a and 12b, protective films 14a and 14b that satisfy optical characteristics as the second retardation layer, and a first retardation layer 16, respectively.

The liquid crystal cell 18 is a homogeneous ECB mode liquid crystal cell. Although the detailed structure is omitted in the figure, in general, it has a pair of transparent substrates and a liquid crystal layer sealed between them, and the alignment of the liquid crystals is controlled on the inner surface of the transparent substrate when no voltage is applied. And an electrode film capable of controlling the alignment of the liquid crystal. The liquid crystalline molecules in the homogeneous ECB liquid crystal cell 18 are aligned substantially parallel to the substrate surface when no voltage is applied, and the twist angle between the substrates depends on the direction of rubbing treatment or the like applied to the alignment film. The direction of rubbing treatment applied to the alignment film is preferably 45 ° or less, and more preferably substantially parallel (± 10 °). By setting it as this range, the substantially parallel orientation (a twist angle is 45 degrees or less) which does not have a twist structure is realizable. The electrode film applies a voltage to the liquid crystal in the liquid crystal cell 18 to control its orientation. The electrode film is normally transparent and is made of, for example, indium tin oxide (ITO). The liquid crystal sealed between the upper and lower transparent substrates is not particularly limited. A material having a positive dielectric anisotropy Δε and generally a refractive index anisotropy Δn = 0.06 to 0.1 (589 nm, 20 ° C.) is used. The thickness d of the liquid crystal layer is about 2.5 to 5 μm. The brightness at the time of white display changes depending on the magnitude of the product Δn · d of the thickness d and the refractive index anisotropy Δn. Therefore, if the brightness is set to be in the range of 200 nm ≦ Δn · d ≦ 400 nm, good brightness is obtained. Is displayed in white. Δnd is more preferably 260 nm to 320 nm.
In the ECB mode liquid crystal display device of this embodiment, when no voltage is applied (in this specification, “no voltage applied” means a state in which no “driving voltage” is applied, and a voltage lower than the driving voltage is applied. In addition, a normally black display method in which black display is performed in a case where the state is included) or a normally white display method in which white display is performed when no voltage is applied may be used. However, a normally black display method is preferable.

  The absorption axes of the polarizing films 12a and 12b are arranged so as to be orthogonal to each other, and are in an orthogonal Nicol arrangement. The absorption axes of the polarizing films 12a and 12b are the alignment directions of liquid crystalline molecules located in the vicinity of the transparent substrate located closer to the liquid crystal cell 18 (generally, the rubbing direction of the alignment film formed on the inner surface). In contrast, it is arranged so as to form approximately 45 °. The polarizing films 12a and 12b generally have a protective film made of a cellulose acylate film or the like that protects the polarizing film on both surfaces, but the protective film that protects the outer surface is omitted in FIG.

In this embodiment shown in FIG. 1, the protective films 14a and 14b of the upper and lower polarizing films 12a and 12b each have an in-plane slow axis, and the in-plane slow axis of the protective film 14a is the absorption axis of the polarizing film 12a. And the in-plane slow axis of the protective film 14b are arranged in parallel with the absorption axis of the polarizing film 12b. The protective films 14a and 14b satisfy the optical characteristics as the second phase layer, that is, satisfy the following formula (1), and contribute to the improvement of the viewing angle characteristics together with the first retardation layer 16 described later. Yes.
(1) −200 nm <Rth (550) <0 nm
It is preferable that the protective films 14a and 14b satisfy the following formula (1) ′ because a wider viewing angle is obtained.
(1) ′ −150 nm ≦ Rth (550) ≦ −70 nm

  The first retardation layer 16 is a layer formed by curing a liquid crystal composition containing a rod-like liquid crystal compound, and the in-plane slow axis of the layer is the average of the major axes of the molecules of the rod-like liquid crystal compound. It is in a direction perpendicular to the orientation direction. In order to cancel the birefringence when the liquid crystal cell 18 is homogeneously aligned, the in-plane retardation Re of the first retardation layer 16 is effective in the normal direction of the panel when the liquid crystal layer of the liquid crystal cell 18 displays black. It is preferable to be equal to retardation. It is preferably equal at least at 550 nm, which is the central wavelength of visible light. As described above, in this embodiment, the effective retardation during black display of the liquid crystal layer is preferably 200 nm to 400 nm, and preferably 260 to 320 nm. Therefore, the surface of the first retardation layer 16 at a wavelength of 550 nm The inner retardation Re (550) is also preferably 200 to 400 nm, and more preferably 260 to 320 nm. The in-plane slow axis of the first retardation layer 16 is preferably approximately 90 ° with respect to the major axis alignment direction of the liquid crystal molecules in the liquid crystal cell 18 during homogeneous alignment.

  The liquid crystal display device of the present invention is not limited to the embodiment shown in FIG. As shown in FIG. 2, as the protective films 15a and 15b on the display surface side or the backlight side, cellulose acylate or the like that does not satisfy the optical characteristics as the second retardation layer may be used. The protective film satisfying the optical characteristics as may be used only for the protective film of one polarizing film. Further, as shown in FIG. 4, the film or the like that satisfies the optical characteristics as the second retardation layer may not be disposed in contact with the surface of the polarizing film, that is, not disposed as a protective film. It may be arranged between the liquid crystal cell 18 and the first retardation layer 16 (14b ′ in FIG. 4). However, in the liquid crystal display device of the present invention, the order is not limited, but the polarizing film, the first retardation layer, the second retardation layer, and the liquid crystal cell are laminated without passing through other retardation regions. It preferably includes a partial structure (however, the stacking order is not limited).

Next, materials used for various members usable in the liquid crystal display device of the present invention, manufacturing methods thereof, and the like will be described in detail.
[First retardation layer]
The first retardation layer is designed to have a preferable retardation according to the birefringence of the liquid crystal cell to be combined. Specifically, it is preferably equal to the birefringence (Δ · d) of the homogeneously aligned liquid crystal layer when no voltage is applied. As described above, in the ECB mode liquid crystal display device, Re (550) is 200 to 200. 400 nm is preferable, and 260 to 320 nm is more preferable. The first retardation layer is a layer formed by curing a liquid crystal composition containing a rod-like liquid crystal compound, and the in-plane slow axis of the layer is the average orientation of the major axes of the molecules of the rod-like liquid crystal compound. It is in a direction perpendicular to the direction.

  Examples of the rod-like liquid crystal compound used for forming the first retardation layer include azomethines, azoxys, cyanobiphenyls, cyanophenyl esters, benzoic acid esters, cyclohexanecarboxylic acid phenyl esters, cyanophenylcyclohexanes. Cyano-substituted phenylpyrimidines, alkoxy-substituted phenylpyrimidines, phenyldioxanes, tolanes and alkenylcyclohexylbenzonitriles are preferably used. Not only the above low-molecular liquid crystalline compounds but also high-molecular liquid crystalline compounds can be used. It is more preferable to fix the alignment of the rod-like liquid crystal compound by polymerization. As the liquid crystalline compound, those having a partial structure capable of causing polymerization or crosslinking reaction by actinic rays, electron beams, heat, or the like are suitably used. The number of the partial structures is preferably 1 to 6, more preferably 1 to 3. As the polymerizable rod-like liquid crystalline compound, Makromol. Chem. 190, 2255 (1989), Advanced Materials 5, 107 (1993), US Pat. No. 4,683,327, US Pat. No. 5,622,648, US Pat. No. 5,770,107, International Publication WO95 / 22586. No. 95/24455, No. 97/00600, No. 98/23580, No. 98/52905, JP-A-1-272551, No. 6-16616, and No. 7-110469. 11-80081, JP 2001-328773, JP 2004-240188, JP 2005-99236, JP 2005-99237, JP 2005-121827, JP It is possible to use the compounds described in 2002-30042 wear.

  The first retardation layer is preferably formed by curing a curable composition containing at least one kind of rod-like liquid crystal compound having two or more photopolymerizable functional groups. For example, the composition is prepared as a coating solution, the coating solution is applied to the surface of a polymer film or the like (preferably the surface of the alignment film), and the coating layer is dried simultaneously with or after drying. It is preferable that the first retardation layer is formed by aligning the molecules, irradiating with ultraviolet rays to advance the polymerization of the liquid crystalline molecules to be cured, and fixing the liquid crystalline molecules in the alignment state. In the photocurable composition, in addition to the rod-like liquid crystalline compound, a polymerization initiator for initiating polymerization, an alignment control agent for bringing the liquid crystalline molecules into a desired alignment state, and improved coating properties A surfactant for the purpose may be added.

  Further, when forming the first retardation layer, an alignment film for aligning rod-shaped liquid crystals may be used. The alignment film is preferably formed by rubbing the surface of the polymer layer. It can be produced in the same manner as an alignment film used for producing a liquid crystal cell.

  The support for supporting the first retardation layer is not particularly limited, and various polymer films and the like can be used. When the second retardation layer is a polymer film such as a cellulose acylate film, the second retardation layer is preferably a support for the first retardation layer. Further, the protective film of the polarizing plate disposed closer to the first retardation layer may be a support, and a commercially available triacetyl cellulose film, a film of norbornene resin, or the like can be used. When a polymer film other than the second retardation layer is used as the support, the polymer film is preferably an optically isotropic film having almost zero retardation. The cellulose acylate film described in No. 138375 is preferable.

[Second retardation layer]
The second retardation layer satisfies the following formula (1), and more preferably satisfies the following formula (1) ′.
(1) −300 nm <Rth (550) <50 nm
(1) ′ −200 nm ≦ Rth (550) ≦ 0 nm
When used in an ECB mode liquid crystal display device, Re (550) preferably satisfies the following formula (2), and more preferably satisfies the following formula (2) ′.
(2) 0 nm ≦ Re (550) ≦ 130 nm

(Second cellulose acylate film for retardation layer)
The second retardation layer may be incorporated in the liquid crystal display device as a protective film for the polarizing film. A cellulose acylate film is preferable as the film having the performance necessary for protecting the polarizing film. Hereinafter, the cellulose acylate film preferably used as the second retardation layer in the present invention will be described in detail.
In the present invention, the cellulose acylate film preferably used as the second retardation layer has a cellulose acylate used as a raw material as a substituent linked to three hydroxyl groups on the β-glucose ring as a constituent unit. It is preferable to have a substituent having a large polarizability anisotropy. By introducing a substituent having a large polarizability anisotropy into the cellulose sylate and adjusting the other substituent and the degree of substitution, the refractive index is maximized in the film thickness direction, and the cellulose satisfies the above formula (1) An acylate film is obtained.

(Distance between substituent ends and polarizability anisotropy)
The polarizability anisotropy of cellulose acylate is defined by the following mathematical formula (A).
Formula (A): Δα = αx− (αy + αz) / 2
(In the formula, αx, αy, and αz are eigenvalues obtained after diagonalizing the polarizability tensor, and αx ≧ αy ≧ αz.) The polarizability anisotropy is in the direction perpendicular to the stretching direction during film stretching. This is related to refractive index expression. That is, when the polarizability anisotropy is small, a slow axis appears in the stretching direction, and when the polarizability anisotropy is large, a slow axis appears in the stretching orthogonal direction. In order to produce a cellulose acylate film satisfying the mathematical formula (A), the polarizability anisotropy of the cellulose acylate as a raw material is preferably as large as possible, preferably 2.5 × 10 ⁻²⁴ cm ⁻³ or more. More preferably 3.5 × 10 ⁻²⁴ cm ⁻³ or more, and particularly preferably 4.5 × 10 ⁻²⁴ cm ⁻³ or more.
In addition, the distance between terminals and the polarizability anisotropy of the substituent of cellulose acylate are calculated using Gaussian 03 (Revision B.03, US Gaussian software). The end-to-end distance is calculated as the distance between the most distant atoms after structural optimization by calculation at the B3LYP / 6-31G * level. The polarizability anisotropy is calculated using the structure optimized at the B3LYP / 6-31G * level, after calculating the polarizability at the 3LYP / 6-311 + G ** level and diagonalizing the obtained polarizability tensor. Calculated from the diagonal component. In the calculation of the distance between the terminal ends of the substituent and the polarizability anisotropy, the substituent linked to the hydroxyl group on the β-glucose ring, which is the structural unit of cellulose acylate, is calculated with the partial structure containing the oxygen atom of the hydroxyl group. And ask.

  The cellulose acylate used for producing the cellulose acylate film is preferably a mixed acid ester having a fatty acid acyl group and a substituted or unsubstituted aromatic acyl group. Here, examples of the substituted or unsubstituted aromatic acyl group include groups represented by the following general formula (1-A).

Formula (1-A)

In general formula (1-A), X is a substituent. Examples of the substituent include a halogen atom, cyano, alkyl group, alkoxy group, aryl group, aryloxy group, acyl group, carbonamido group, and sulfonamido group. Ureido group, aralkyl group, nitro, alkoxycarbonyl group, aryloxycarbonyl group, aralkyloxycarbonyl group, carbamoyl group, sulfamoyl group, acyloxy group, alkenyl group, alkynyl group, alkylsulfonyl group, arylsulfonyl group, alkyloxysulfonyl group , Aryloxysulfonyl group, alkylsulfonyloxy group and aryloxysulfonyl group, —S—R, —NH—CO—OR, —PH—R, —P (—R) ₂ , —PH—O—R, —P (-R) (- O-R ), - P (-O-R) 2, -PH (= O) -R P (= O) (- R ) 2, -PH (= O) -O-R, -P (= O) (- R) (- O-R), - P (= O) (- O-R ) ₂ , —O—PH (═O) —R, —O—P (═O) (— R) ₂ —O—PH (═O) —O—R, —O—P (═O) (— R) (— O—R), —O—P (═O) (— O—R) ₂ , —NH—PH (═O) —R, —NH—P (═O) (— R) (— O—R), —NH—P (═O) (— O—R) ₂ , —SiH ₂ —R, —SiH (—R) ₂ , —Si (—R) ₃ , —O—SiH ₂ —R , -O-SiH (-R) ₂ and -O-Si (-R) ₃ . R is an aliphatic group, an aromatic group or a heterocyclic group. The number of substituents is preferably from 1 to 5, more preferably from 1 to 4, more preferably from 1 to 3, and even more preferably 1 or 2. As the substituent, a halogen atom, cyano, alkyl group, alkoxy group, aryl group, aryloxy group, acyl group, carbonamido group, sulfonamido group and ureido group are preferable, halogen atom, cyano, alkyl group, alkoxy group, An aryloxy group, an acyl group and a carbonamido group are more preferred, a halogen atom, cyano, an alkyl group, an alkoxy group and an aryloxy group are more preferred, and a halogen atom, an alkyl group and an alkoxy group are still more preferred.

  The halogen atom includes a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. The alkyl group is most preferred. Examples of the alkyl group include methyl, ethyl, propyl, isopropyl, butyl, t-butyl, hexyl, cyclohexyl, octyl and 2-ethylhexyl. The alkoxy group may have a cyclic structure or a branch. The number of carbon atoms in the alkoxy group is preferably 1-20, more preferably 1-12, still more preferably 1-6, and even more preferably 1-4. The alkoxy group may be further substituted with another alkoxy group. Examples of the alkoxy group include methoxy, ethoxy, 2-methoxyethoxy, 2-methoxy-2-ethoxyethoxy, butyloxy, hexyloxy and octyloxy.

  The number of carbon atoms of the aryl group is preferably 6-20, and more preferably 6-12. Examples of the aryl group include phenyl and naphthyl. The aryloxy group preferably has 6 to 20 carbon atoms, more preferably 6 to 12 carbon atoms. Examples of the aryloxy group include phenoxy and naphthoxy. The number of carbon atoms in the acyl group is preferably 1-20, and more preferably 1-12. Examples of acyl groups include formyl, acetyl and benzoyl. The number of carbon atoms of the carbonamide group is preferably 1-20, and more preferably 1-12. Examples of the carbonamido group include acetamide and benzamide. The number of carbon atoms in the sulfonamide group is preferably 1-20, and more preferably 1-12. Examples of the sulfonamide group include methanesulfonamide, benzenesulfonamide, and p-toluenesulfonamide. The number of carbon atoms in the ureido group is preferably 1-20, and more preferably 1-12. Examples of ureido groups include (unsubstituted) ureido.

The alkyl group may have a cyclic structure or a branch. The number of carbon atoms of the alkyl group is preferably 1-20, more preferably 1-12, still more preferably 1-6, and 1-4.
The number of carbon atoms in the aralkyl group is preferably 7-20, and more preferably 7-12. Examples of aralkyl groups include benzyl, phenethyl and naphthylmethyl. The number of carbon atoms of the alkoxycarbonyl group is 1-20.

Is more preferable, and 2 to 12 is more preferable. Examples of the alkoxycarbonyl group include methoxycarbonyl. The aryloxycarbonyl group preferably has 7 to 20 carbon atoms, and more preferably 7 to 12 carbon atoms. Examples of the aryloxycarbonyl group include phenoxycarbonyl. The number of carbon atoms in the aralkyloxycarbonyl group is preferably 8-20, and more preferably 8-12. Examples of the aralkyloxycarbonyl group include benzyloxycarbonyl. The number of carbon atoms of the carbamoyl group is preferably 1-20, and more preferably 1-12. Examples of the carbamoyl group include (unsubstituted) carbamoyl and N-methylcarbamoyl. The number of carbon atoms in the sulfamoyl group is preferably 20 or less, and more preferably 12 or less. Examples of sulfamoyl groups include (unsubstituted) sulfamoyl and N-methylsulfamoyl. The number of carbon atoms in the acyloxy group is preferably 1-20, and more preferably 2-12. Examples of the acyloxy group include acetoxy and benzoyloxy.

  The alkenyl group has preferably 2 to 20 carbon atoms, and more preferably 2 to 12 carbon atoms. Examples of alkenyl groups include vinyl, allyl and isopropenyl. The number of carbon atoms in the alkynyl group is preferably 2-20, and more preferably 2-12. Examples of alkynyl groups include thienyl. The number of carbon atoms in the alkylsulfonyl group is preferably 1-20, and more preferably 1-12. The number of carbon atoms of the arylsulfonyl group is preferably 6-20, and more preferably 6-12. The alkyloxysulfonyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms. The number of carbon atoms of the aryloxysulfonyl group is preferably 6-20, and more preferably 6-12. The alkyloxysulfonyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms. The number of carbon atoms of the aryloxysulfonyl group is preferably 6-20, and more preferably 6-12.

  In the fatty acid ester residue in the cellulose mixed acid ester, the aliphatic acyl group preferably has 2 to 20 carbon atoms, specifically acetyl, propionyl, butyryl, isobutyryl, valeryl, pivaloyl, hexanoyl, octanoyl, Examples include lauroyl and stearoyl. Acetyl, propionyl and butyryl are preferred, and acetyl is particularly preferred. In addition, an aliphatic acyl group is meant to include those further having a substituent, and examples of the substituent include those exemplified as X in the general formula (1-A).

  In the general formula (1-A), the number (n) of substituents X substituted on the aromatic ring is 0 or 1 to 5, preferably 1 to 3, and particularly preferably 1 or Two.

  Further, when the number of substituents substituted on the aromatic ring is 2 or more, they may be the same or different from each other, but they may be linked together to form a condensed polycyclic compound (for example, naphthalene, indene, indane, phenanthrene, quinoline). , Isoquinoline, chromene, chroman, phthalazine, acridine, indole, indoline, etc.). Specific examples of the aromatic acyl group represented by the general formula (1-A) are as shown below. 1, 3, 5, 6, 8, 13, 18, 28, more preferably 1, 3, 6, and 13.

  Examples of the method for substituting the hydroxyl group of cellulose with an aromatic acyl group generally include a method using a symmetric acid anhydride and a mixed acid anhydride derived from an aromatic carboxylic acid claloid or an aromatic carboxylic acid. . Particularly preferred is a method using an acid anhydride derived from an aromatic carboxylic acid (described in Journal of Applied Polymer Science, Vol. 29, 3981-3990 (1984)). As a method for producing the cellulose mixed acid ester compound of the present invention as the above method, (1) a cellulose fatty acid monoester or diester is once produced, and then the remaining hydroxyl group is represented by the general formula (1-A). And (2) a method in which a mixed acid anhydride of an aliphatic carboxylic acid and an aromatic carboxylic acid is reacted directly with cellulose. In the former, the production method of the cellulose fatty acid ester or diester is a well-known method, but the subsequent reaction for introducing an aromatic acyl group into this further varies depending on the type of the aromatic acyl group, but preferably the reaction temperature. The reaction time is 0 to 100 ° C., more preferably 20 to 50 ° C., and the reaction time is preferably 30 minutes or more, more preferably 30 to 300 minutes. In the latter method using the mixed acid anhydride, the reaction conditions vary depending on the type of the mixed acid anhydride, but the reaction temperature is preferably 0 to 100 ° C., more preferably 20 to 50 ° C., and the reaction time is preferably 30 to 300. Minutes, more preferably 60 to 200 minutes. In any of the above reactions, the reaction may be performed in the absence of a solvent or in a solvent, but is preferably performed using a solvent. As the solvent, dichloromethane, chloroform, dioxane and the like can be used.

In the present invention, the degree of substitution is 3.0 when the hydroxyl group of cellulose is substituted 100%. The degree of substitution can be determined from the peak intensity of the carbonyl carbon in the acyl group in C ¹³ -NMR.
In the case of a cellulose fatty acid monoester, the degree of substitution of the aromatic acyl group is 2.0 or less, preferably 0.1 to 2.0, more preferably 0.1 to 1.0 with respect to the remaining hydroxyl group. In the case of cellulose fatty acid diester (cellulose diacetate), it is 1.0 or less, preferably 0.1 to 1.0, based on the remaining hydroxyl group. Moreover, it is preferable that the total substitution degree PA of a cellulose acylate is 2.4-3.

  The cellulose acylate preferably has a mass average degree of polymerization of 350 to 800, and more preferably has a mass average degree of polymerization of 370 to 600. The cellulose acylate used in the present invention preferably has a number average molecular weight of 70000 to 230,000, more preferably 75000 to 230,000, and more preferably 78000 to 120,000. Further preferred.

  The cellulose acylate can be synthesized using an acid anhydride or acid chloride as an acylating agent. When the acylating agent is an acid anhydride, an organic acid (for example, acetic acid) or methylene chloride is used as a reaction solvent. As the catalyst, a protic catalyst such as sulfuric acid is used. When the acylating agent is an acid chloride, a basic compound is used as a catalyst. In the most common synthetic method in the industry, cellulose is an organic acid corresponding to acetyl group and other acyl groups (acetic acid, propionic acid, butyric acid) or their acid anhydrides (acetic anhydride, propionic anhydride, butyric anhydride). A cellulose ester is synthesized by esterification with a mixed organic acid component containing.

  In this method, cellulose such as cotton linter and wood pulp is activated with an organic acid such as acetic acid, and then esterified using a mixture of organic acid components as described above in the presence of a sulfuric acid catalyst. There are many cases to do. The organic acid anhydride component is generally used in an excess amount relative to the amount of hydroxyl groups present in the cellulose. In this esterification treatment, in addition to the esterification reaction, a hydrolysis reaction (depolymerization reaction) of the cellulose main chain β1 → 4-glycoside bond) proceeds. When the hydrolysis reaction of the main chain proceeds, the degree of polymerization of the cellulose ester is lowered, and the physical properties of the cellulose ester film to be produced are lowered. Therefore, the reaction conditions such as the reaction temperature are preferably determined in consideration of the degree of polymerization and molecular weight of the resulting cellulose ester.

  In order to obtain a cellulose ester having a high degree of polymerization (high molecular weight), it is important to adjust the maximum temperature in the esterification reaction step to 50 ° C. or lower. The maximum temperature is preferably adjusted to 35 to 50 ° C, more preferably 37 to 47 ° C. A reaction temperature of 35 ° C. or higher is preferable because the esterification reaction proceeds smoothly. A reaction temperature of 50 ° C. or lower is preferable because inconveniences such as a decrease in the degree of polymerization of the cellulose ester do not occur.

  After the esterification reaction, when the reaction is stopped while suppressing the temperature rise, a decrease in the polymerization degree can be further suppressed, and a cellulose ester having a high polymerization degree can be synthesized. That is, when a reaction terminator (for example, water or acetic acid) is added after completion of the reaction, the excess acid anhydride that did not participate in the esterification reaction is hydrolyzed to form a corresponding organic acid as a by-product. This hydrolysis reaction is accompanied by intense heat generation, and the temperature in the reactor rises. If the rate of addition of the reaction terminator is not too high, heat is rapidly generated exceeding the cooling capacity of the reactor, the hydrolysis reaction of the cellulose main chain proceeds significantly, and the degree of polymerization of the resulting cellulose ester decreases. Such a problem does not occur. In addition, a part of the catalyst is bonded to the cellulose during the esterification reaction, and most of the catalyst is dissociated from the cellulose during the addition of the reaction terminator. If the rate of addition of the reaction terminator is not too high at this time, a sufficient reaction time is secured for dissociating the catalyst, and problems such as part of the catalyst remaining in a state of being bound to cellulose are unlikely to occur. Cellulose esters to which a strong acid catalyst is partially bonded are very poor in stability, and are easily decomposed by heat during drying of the product to lower the degree of polymerization. For these reasons, after the esterification reaction, it is preferable to stop the reaction by adding a reaction terminator over a period of preferably 4 minutes or more, more preferably 4 to 30 minutes. In addition, it is preferable if the addition time of the reaction terminator is 30 minutes or less because problems such as a decrease in industrial productivity do not occur.

  As the reaction terminator, water or alcohol that decomposes an acid anhydride is generally used. However, in the present invention, a mixture of water and an organic acid is preferably used as a reaction terminator in order not to precipitate triesters having low solubility in various organic solvents. When the esterification reaction is carried out under the above conditions, a high molecular weight cellulose ester having a mass average polymerization degree of 500 or more can be easily synthesized.

  In the cellulose acylate film satisfying the general formula (1), a compound (also referred to as an Rth reducing agent) that lowers Rth may be used in order to achieve a desired retardation Rth in the thickness direction. The Rth-reducing compound is preferably contained in an amount of 0.01 to 30% by mass, more preferably 0.1 to 25% by mass, and still more preferably 0.1 to 20%, based on the cellulose acylate solid content. % By mass.

The compound that lowers Rth is sufficiently compatible with cellulose acylate, and it is advantageous that the compound itself does not have a rod-like structure or a planar structure. Specifically, when a plurality of planar functional groups such as aromatic groups are provided, a structure having these functional groups in a non-planar rather than the same plane is advantageous.
In producing the cellulose acylate film used in the present invention, among the compounds that reduce the optical anisotropy by inhibiting the cellulose acylate in the film from being oriented in the plane and in the film thickness direction as described above, Compounds having an octanol-water partition coefficient (log P value) of 0 to 7 are preferred. A compound having a log P value of 7 or less is excellent in compatibility with cellulose acylate, and hardly causes white turbidity or powder blowing of the film. A compound having a log P value of 0 or more is suitable for hydrophilicity and improves the water resistance of the cellulose acylate film. A more preferable range for the logP value is 1 to 6, and a particularly preferable range is 1.5 to 5.
The octanol-water partition coefficient (log P value) can be measured by a flask immersion method described in JIS Japanese Industrial Standard Z7260-107 (2000). Further, the octanol-water partition coefficient (log P value) can be estimated by a computational chemical method or an empirical method instead of the actual measurement. As a calculation method, Crippen's fragmentation method (J. Chem. Inf. Comput. Sci., 27, 21 (1987)), Viswanadhan's fragmentation method (J. Chem. Inf. Comput. Sci., 29,). 163 (1989).), Broto's fragmentation method (Eur. J. Med. Chem.-Chim. Theor., 19, 71 (1984).) And the like are preferably used, but the Crippen's fragmentation method (J. Chem. Inf. Comput. Sci., 27, 21 (1987). When the log P value of a certain compound varies depending on the measurement method or calculation method, it is preferable to determine whether or not the compound is within the scope of the present invention by the Crippen's fragmentation method.

The compound that lowers Rth may or may not contain an aromatic group. The compound that reduces the optical anisotropy preferably has a molecular weight of 150 or more and 3000 or less, preferably 170 or more and 2000 or less, and particularly preferably 200 or more and 1000 or less. A specific monomer structure may be used as long as these molecular weights are within the range, and an oligomer structure or a polymer structure in which a plurality of the monomer units are bonded may be used.
The compound that lowers Rth is preferably a liquid at 25 ° C. or a solid having a melting point of 25 to 250 ° C., more preferably a liquid at 25 ° C. or a solid having a melting point of 25 to 200 ° C. is there. Moreover, it is preferable that the compound which reduces optical anisotropy does not volatilize in the process of dope casting for cellulose acylate film production and drying.
A compound that lowers Rth may be used alone, or two or more compounds may be mixed and used in an arbitrary ratio.
The timing of adding the compound that lowers Rth may be any time during the dope preparation process, or may be performed at the end of the dope preparation process.

  In the compound that reduces Rth, the average content of the compound in the portion from the surface on at least one side to 10% of the total film thickness is 80- of the average content of the compound in the central portion of the cellulose acylate film. 99%. The abundance of the compound of the present invention can be determined, for example, by measuring the amount of the compound at the surface and in the center by the method using an infrared absorption spectrum described in JP-A-8-57879.

  Although the specific example of the compound which reduces Rth used for preparation of the cellulose acylate film used preferably as said 1st phase difference layer below is shown, it is not limited to these compounds.

General formula (B)

In the general formula (B), R ¹¹ represents an alkyl group or an aryl group, and R ¹² and R ¹³ each independently represent a hydrogen atom, an alkyl group, or an aryl group. Further, it is particularly preferable that the total number of carbon atoms of R ¹¹ , R ¹² and R ¹³ is 10 or more.

  The above alkyl group and aryl group may have a substituent, and the substituent is preferably a fluorine atom, an alkyl group, an aryl group, an alkoxy group, a sulfone group, or a sulfonamide group, and an alkyl group, an aryl group, an alkoxy group. Particularly preferred are groups, sulfone groups and sulfonamide groups.

  The alkyl group may be linear, branched or cyclic, and preferably has 1 to 25 carbon atoms, more preferably 6 to 25, and more preferably 6 to 20 ( For example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, amyl, isoamyl, t-amyl, hexyl, cyclohexyl, heptyl, octyl, bicyclooctyl, nonyl, adamantyl, decyl, t-octyl, undecyl, dodecyl , Tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, didecyl, etc.) are particularly preferred.

As the aryl group, those having 6 to 30 carbon atoms are preferable, and those having 6 to 24 carbon atoms (for example, phenyl, biphenyl, terphenyl, naphthyl, binaphthyl, triphenylphenyl, etc.) are particularly preferable.
Although the preferable example of a compound represented by general formula (B) below is shown, it is not limited to these specific examples.

General formula (C)

In the general formula (C), R ³¹ represents an alkyl group or an aryl group, and R ³² and R ³³ each independently represent a hydrogen atom, an alkyl group, or an aryl group. Here, the alkyl group may be linear, branched or cyclic, and preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and 1 to 12 carbon atoms. Are even more preferred. As the cyclic alkyl group, a cyclohexyl group is particularly preferable. The aryl group preferably has 6 to 36 carbon atoms, and more preferably 6 to 24 carbon atoms.

  The above alkyl group and aryl group may have a substituent. Examples of the substituent include a halogen atom (for example, chlorine, bromine, fluorine and iodine), an alkyl group, an aryl group, an alkoxy group, an aryloxy group, An acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an acyloxy group, a sulfonylamino group, a hydroxy group, a cyano group, an amino group, and an acylamino group are preferable, and a halogen atom, an alkyl group, an aryl group, an alkoxy group, and an aryloxy are more preferable. Group, sulfonylamino group and acylamino group, particularly preferably alkyl group, aryl group, sulfonylamino group and acylamino group.

  Preferred examples of the compound represented by the general formula (C) are shown below, but the present invention is not limited to these specific examples.

The cellulose acylate film may contain a wavelength dispersion adjusting agent in order to obtain a desired wavelength dispersion.
Specific examples of the wavelength dispersion adjusting agent include, for example, benzotriazole compounds, benzophenone compounds, cyano group-containing compounds, oxybenzophenone compounds, salicylic acid ester compounds, nickel complex compounds, and the like. It is not limited to.

As the benzotriazole-based compound, those represented by the general formula (101) are preferably used as the wavelength dispersion adjusting agent of the present invention.
Formula (101) Q ¹ -Q ² -OH
In the formula, Q ¹ represents a nitrogen-containing aromatic heterocycle, and Q ² represents an aromatic ring.

Q ¹ represents a nitrogen-containing aromatic heterocycle, preferably a 5- to 7-membered nitrogen-containing aromatic heterocycle, more preferably a 5- to 6-membered nitrogen-containing aromatic heterocycle, such as imidazole, Pyrazole, triazole, tetrazole, thiazole, oxazole, selenazole, benzotriazole, benzothiazole, benzoxazole, benzoselenazole, thiadiazole, oxadiazole, naphthothiazole, naphthoxazole, azabenzimidazole, purine, pyridine, pyrazine, pyrimidine, pyridazine , Triazine, triazaindene, tetrazaindene and the like, more preferably a 5-membered nitrogen-containing aromatic heterocycle, specifically, imidazole, pyrazole, triazole, tetrazole, thiazole, oxazol. , Benzotriazole, benzothiazole, benzoxazole, thiadiazole, oxadiazole preferably, particularly preferably benzotriazole.
The nitrogen-containing aromatic heterocycle represented by Q ¹ may further have a substituent, and the substituent can be selected from the substituent T described later. In addition, when there are a plurality of substituents, each may be condensed to further form a ring.

The aromatic ring represented by Q ² may be an aromatic hydrocarbon ring or an aromatic heterocycle. These may be monocyclic or may form a condensed ring with another ring.
The aromatic hydrocarbon ring is preferably (preferably a monocyclic or bicyclic aromatic hydrocarbon ring having 6 to 30 carbon atoms (for example, benzene ring, naphthalene ring etc.), more preferably 6 carbon atoms. -20 aromatic hydrocarbon ring, more preferably an aromatic hydrocarbon ring having 6 to 12 carbon atoms.) More preferred is a benzene ring.
The aromatic heterocycle is preferably an aromatic heterocycle containing a nitrogen atom or a sulfur atom. Specific examples of the heterocyclic ring include, for example, thiophene, imidazole, pyrazole, pyridine, pyrazine, pyridazine, triazole, triazine, indole, indazole, purine, thiazoline, thiazole, thiadiazole, oxazoline, oxazole, oxadiazole, quinoline, isoquinoline, Examples include phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, pteridine, acridine, phenanthroline, phenazine, tetrazole, benzimidazole, benzoxazole, benzthiazole, benzotriazole, and tetrazaindene. Preferred examples of the aromatic heterocycle include pyridine, triazine, and quinoline.
The aromatic ring represented by Q ² is preferably an aromatic hydrocarbon ring, more preferably a naphthalene ring or a benzene ring, and particularly preferably a benzene ring. Q ² may further have a substituent, and is preferably selected from the substituent T described below.

  The substituent T includes an alkyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms, such as methyl, ethyl, iso-propyl, tert-butyl, and n-octyl, n-decyl, n-hexadecyl, cyclopropyl, cyclopentyl, cyclohexyl, etc.), an alkenyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, and particularly preferably carbon number). 2 to 8, for example, vinyl, allyl, 2-butenyl, 3-pentenyl, etc.), an alkynyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, and particularly preferably carbon number). 2-8, for example, propargyl, 3-pentynyl, etc.), aryl groups (preferably 6-30 carbons, more preferred) Or having 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as phenyl, p-methylphenyl, naphthyl, etc.), a substituted or unsubstituted amino group (preferably having 0 to 20 carbon atoms). More preferably 0 to 10 carbon atoms, particularly preferably 0 to 6 carbon atoms, such as amino, methylamino, dimethylamino, diethylamino, dibenzylamino, etc.), an alkoxy group (preferably having 1 carbon atom). To 20, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms, such as methoxy, ethoxy, butoxy, etc.), an aryloxy group (preferably 6 to 20 carbon atoms, more preferably). Has 6 to 16 carbon atoms, particularly preferably 6 to 12 carbon atoms, and examples thereof include phenyloxy and 2-naphthyloxy. ), An acyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, and examples thereof include acetyl, benzoyl, formyl, pivaloyl, etc.), alkoxycarbonyl A group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 12 carbon atoms, such as methoxycarbonyl, ethoxycarbonyl, etc.), an aryloxycarbonyl group (preferably 7 to 20 carbon atoms, more preferably 7 to 16 carbon atoms, particularly preferably 7 to 10 carbon atoms, such as phenyloxycarbonyl, etc.), acyloxy group (preferably 2 to 20 carbon atoms, more preferably Has 2 to 16 carbon atoms, particularly preferably 2 to 10 carbon atoms, such as acetoxy, benzoyl Examples include oxy. ), An acylamino group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 10 carbon atoms, and examples thereof include acetylamino and benzoylamino), alkoxycarbonylamino group (Preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 12 carbon atoms, such as methoxycarbonylamino), aryloxycarbonylamino group (preferably having carbon number) 7 to 20, more preferably 7 to 16 carbon atoms, particularly preferably 7 to 12 carbon atoms, such as phenyloxycarbonylamino, and the like, and sulfonylamino groups (preferably 1 to 20 carbon atoms, more preferably Has 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms. And sulfamoyl group (preferably having 0 to 20 carbon atoms, more preferably 0 to 16 carbon atoms, particularly preferably 0 to 12 carbon atoms, such as sulfamoyl and methylsulfamoyl). , Dimethylsulfamoyl, phenylsulfamoyl, etc.), a carbamoyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as carbamoyl). , Methylcarbamoyl, diethylcarbamoyl, phenylcarbamoyl, etc.), an alkylthio group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as methylthio, Ethylthio etc.), arylthio group (preferably Has 6 to 20 carbon atoms, more preferably 6 to 16 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as phenylthio, and a sulfonyl group (preferably 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as mesyl, tosyl, etc.), sulfinyl group (preferably 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably Has 1 to 12 carbon atoms, such as methanesulfinyl, benzenesulfinyl, etc.), ureido group (preferably 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms). For example, ureido, methylureido, phenylureido, etc.), phosphoric acid amide group (preferably having 1 to 20 carbon atoms) More preferably, it is C1-C16, Most preferably, it is C1-C12, for example, diethyl phosphoric acid amide, phenylphosphoric acid amide etc. are mentioned. ), Hydroxy group, mercapto group, halogen atom (eg fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, sulfo group, carboxyl group, nitro group, hydroxamic acid group, sulfino group, hydrazino group, imino group, Heterocyclic group (preferably having 1 to 30 carbon atoms, more preferably 1 to 12 carbon atoms, and examples of the hetero atom include a nitrogen atom, an oxygen atom, a sulfur atom, specifically, for example, imidazolyl, pyridyl, quinolyl, furyl, piperidyl , Morpholino, benzoxazolyl, benzimidazolyl, benzthiazolyl, etc.), silyl group (preferably having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, and particularly preferably 3 to 24 carbon atoms). And examples thereof include trimethylsilyl and triphenylsilyl). These substituents may be further substituted. Moreover, when there are two or more substituents, they may be the same or different. If possible, they may be linked together to form a ring.

  Preferred as the general formula (101) is a compound represented by the following general formula (101-A).

General formula (101-A)

In the formula, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , and R ⁸ each independently represent a hydrogen atom or a substituent.

R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , and R ⁸ each independently represent a hydrogen atom or a substituent, and the substituent is preferably selected from the aforementioned substituent T. Further, these substituents may be further substituted with another substituent, and the substituents may be condensed to form a ring structure.
R ¹ and R ³ are preferably hydrogen atoms, alkyl groups, alkenyl groups, alkynyl groups, aryl groups, substituted or unsubstituted amino groups, alkoxy groups, aryloxy groups, hydroxy groups, and halogen atoms, more preferably hydrogen atoms. An atom, an alkyl group, an aryl group, an alkyloxy group, an aryloxy group and a halogen atom, more preferably a hydrogen atom and an alkyl group having 1 to 12 carbon atoms, particularly preferably an alkyl group having 1 to 12 carbon atoms (preferably 4 to 12 carbon atoms).

R ² and R ⁴ are preferably hydrogen atoms, alkyl groups, alkenyl groups, alkynyl groups, aryl groups, substituted or unsubstituted amino groups, alkoxy groups, aryloxy groups, hydroxy groups, and halogen atoms, more preferably hydrogen atoms. An atom, an alkyl group, an aryl group, an alkyloxy group, an aryloxy group, and a halogen atom, more preferably a hydrogen atom and an alkyl group having 1 to 12 carbon atoms, particularly preferably a hydrogen atom and a methyl group, most preferably It is a hydrogen atom.

R ⁵ and R ⁸ are preferably hydrogen atoms, alkyl groups, alkenyl groups, alkynyl groups, aryl groups, substituted or unsubstituted amino groups, alkoxy groups, aryloxy groups, hydroxy groups, and halogen atoms, more preferably hydrogen atoms. An atom, an alkyl group, an aryl group, an alkyloxy group, an aryloxy group, and a halogen atom, more preferably a hydrogen atom and an alkyl group having 1 to 12 carbon atoms, particularly preferably a hydrogen atom and a methyl group, most preferably It is a hydrogen atom.

R ⁶ and R ⁷ are preferably a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a substituted or unsubstituted amino group, an alkoxy group, an aryloxy group, a hydroxy group, and a halogen atom, more preferably a hydrogen atom. An atom, an alkyl group, an aryl group, an alkyloxy group, an aryloxy group, and a halogen atom, more preferably a hydrogen atom and a halogen atom, and particularly preferably a hydrogen atom and a chlorine atom.

  More preferable as the general formula (101) is a compound represented by the following general formula (101-B).

General formula (101-B)

In the formula, R ¹ , R ³ , R ⁶ and R ⁷ have the same meanings as those in formula (101-A), and preferred ranges are also the same.

  Specific examples of the compound represented by formula (101) are listed below, but the present invention is not limited to the following specific examples.

  Of the benzotriazole compounds exemplified above, compounds having a molecular weight of 320 or less are preferably used.

  As the wavelength dispersion adjusting agent, a benzophenone compound represented by the general formula (102) is also preferably used.

General formula (102)

In general formula (102), Q ¹ and Q ² each independently represents an aromatic ring. X represents NR (R represents a hydrogen atom or a substituent), an oxygen atom or a sulfur atom.

In the general formula (102), the aromatic ring represented by Q ¹ and Q ² may be an aromatic hydrocarbon ring or an aromatic heterocycle. These may be monocyclic or may form a condensed ring with another ring.
The aromatic hydrocarbon ring represented by Q ¹ and Q ² is preferably (preferably a monocyclic or bicyclic aromatic hydrocarbon ring having 6 to 30 carbon atoms (for example, a benzene ring, a naphthalene ring, etc.). More preferably an aromatic hydrocarbon ring having 6 to 20 carbon atoms, still more preferably an aromatic hydrocarbon ring having 6 to 12 carbon atoms.) More preferably, it is a benzene ring.
The aromatic heterocycle represented by Q ¹ and Q ² is preferably an aromatic heterocycle containing at least one of an oxygen atom, a nitrogen atom or a sulfur atom. Specific examples of the heterocyclic ring include, for example, furan, pyrrole, thiophene, imidazole, pyrazole, pyridine, pyrazine, pyridazine, triazole, triazine, indole, indazole, purine, thiazoline, thiazole, thiadiazole, oxazoline, oxazole, oxadiazole, Examples include quinoline, isoquinoline, phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, pteridine, acridine, phenanthroline, phenazine, tetrazole, benzimidazole, benzoxazole, benzothiazole, benzotriazole, and tetrazaindene. Preferred examples of the aromatic heterocycle include pyridine, triazine, and quinoline.
The aromatic ring represented by Q ¹ and Q ² is preferably an aromatic hydrocarbon ring, more preferably an aromatic hydrocarbon ring having 6 to 10 carbon atoms, still more preferably a substituted or unsubstituted benzene ring. is there.
Q ¹ and Q ² may further have a substituent, and are preferably selected from the aforementioned substituent T, but the substituent does not contain a carboxylic acid, a sulfonic acid, or a quaternary ammonium salt. Further, if possible, substituents may be linked to form a ring structure.

  X represents NR (R represents a hydrogen atom or a substituent. The substituent may be selected from the aforementioned substituent T), an oxygen atom or a sulfur atom, and X is preferably NR (preferably R is An acyl group and a sulfonyl group, and these substituents may be further substituted.) Or O, and particularly preferably O.

  As the general formula (102), a compound represented by the following general formula (102-A) is preferable.

Formula (102-A)

In General Formula (102-A), R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , and R ⁹ each independently represent a hydrogen atom or a substituent.

In the general formula (102-A), R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , and R ⁹ each independently represents a hydrogen atom or a substituent. The group can be selected from the aforementioned substituent T. Further, these substituents may be further substituted with another substituent, and the substituents may be condensed to form a ring structure.

R ¹ , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁸ and R ⁹ are preferably hydrogen, alkyl, alkenyl, alkynyl, aryl, substituted or unsubstituted amino, alkoxy, aryl An oxy group, a hydroxy group and a halogen atom, more preferably a hydrogen atom, an alkyl group, an aryl group, an alkyloxy group, an aryloxy group and a halogen atom, still more preferably a hydrogen atom and a carbon 1-12 alkyl group. Particularly preferred are a hydrogen atom and a methyl group, and most preferred is a hydrogen atom.

R ² is preferably a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a substituted or unsubstituted amino group, an alkoxy group, an aryloxy group, a hydroxy group, a halogen atom, more preferably a hydrogen atom or one carbon atom. An alkyl group having -20 carbon atoms, an amino group having 0-20 carbon atoms, an alkoxy group having 1-12 carbon atoms, an aryloxy group having 6-12 carbon atoms, and a hydroxy group, and more preferably an alkoxy group having 1-20 carbon atoms. And particularly preferably an alkoxy group having 1 to 12 carbon atoms.

R ⁷ is preferably a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a substituted or unsubstituted amino group, an alkoxy group, an aryloxy group, a hydroxy group, a halogen atom, more preferably a hydrogen atom or a carbon number of 1 An alkyl group having -20 carbon atoms, an amino group having 0-20 carbon atoms, an alkoxy group having 1-12 carbon atoms, an aryloxy group having 6-12 carbon atoms, and a hydroxy group, more preferably a hydrogen atom, having 1-20 carbon atoms. An alkyl group (preferably having 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms, still more preferably a methyl group), particularly preferably a methyl group or a hydrogen atom.

  More preferable as the general formula (102) is a compound represented by the following general formula (102-B).

General formula (102-B)

In General Formula (102-B), R ¹⁰ represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, or a substituted or unsubstituted aryl group.

R ¹⁰ represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, or a substituted or unsubstituted aryl group, and these substituents are the aforementioned substituents T can be selected.
R ¹⁰ is preferably a substituted or unsubstituted alkyl group, more preferably a substituted or unsubstituted alkyl group having 5 to 20 carbon atoms, and still more preferably a substituted or unsubstituted alkyl group having 5 to 12 carbon atoms. (Including n-hexyl group, 2-ethylhexyl group, n-octyl group, n-decyl group, n-dodecyl group, benzyl group, etc.), particularly preferably a substitution of 6 to 12 carbon atoms or It is an unsubstituted alkyl group (2-ethylhexyl group, n-octyl group, n-decyl group, n-dodecyl group, benzyl group).

The compound represented by the general formula (102) can be synthesized by a known method described in JP-A-11-12219.
Specific examples of the compound represented by the general formula (102) are given below, but the present invention is not limited to the following specific examples.

  Moreover, it is also preferable to use the compound containing the cyano group represented by General formula (103) as said wavelength dispersion regulator.

General formula (103)

In general formula (103), Q ¹ and Q ² each independently represents an aromatic ring. X ¹ and X ² each represent a hydrogen atom or a substituent, at least one of which is a cyano group, and the other preferably represents a carbonyl group, a sulfonyl group or an aromatic heterocycle. ) The aromatic ring represented by Q ¹ and Q ² may be an aromatic hydrocarbon ring or an aromatic heterocycle. These may be monocyclic or may form a condensed ring with another ring.

  The aromatic hydrocarbon ring is preferably (preferably a monocyclic or bicyclic aromatic hydrocarbon ring having 6 to 30 carbon atoms (for example, benzene ring, naphthalene ring etc.), more preferably 6 carbon atoms. -20 aromatic hydrocarbon ring, more preferably an aromatic hydrocarbon ring having 6 to 12 carbon atoms.) More preferred is a benzene ring.

  The aromatic heterocycle is preferably an aromatic heterocycle containing a nitrogen atom or a sulfur atom. Specific examples of the heterocyclic ring include, for example, thiophene, imidazole, pyrazole, pyridine, pyrazine, pyridazine, triazole, triazine, indole, indazole, purine, thiazoline, thiazole, thiadiazole, oxazoline, oxazole, oxadiazole, quinoline, isoquinoline, Examples include phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, pteridine, acridine, phenanthroline, phenazine, tetrazole, benzimidazole, benzoxazole, benzthiazole, benzotriazole, and tetrazaindene. Preferred examples of the aromatic heterocycle include pyridine, triazine, and quinoline.

The aromatic ring represented by Q ¹ and Q ² is preferably an aromatic hydrocarbon ring, and more preferably a benzene ring.
Q ¹ and Q ² may further have a substituent, and are preferably selected from the aforementioned substituent T.

X ¹ and X ² each represent a hydrogen atom or a substituent, at least one of which is a cyano group, and the other preferably represents a carbonyl group, a sulfonyl group, or an aromatic heterocycle. The substituent represented by X ¹ and X ² can be selected from the aforementioned substituent T. In addition, the substituent represented by X ¹ and X ² may be further substituted with another substituent, and X ¹ and X ² may be condensed to form a ring structure.

X ¹ and X ² are preferably a hydrogen atom, an alkyl group, an aryl group, a cyano group, a nitro group, a carbonyl group, a sulfonyl group, or an aromatic heterocycle, and more preferably a cyano group, a carbonyl group, a sulfonyl group, An aromatic heterocycle, more preferably a cyano group or a carbonyl group, and particularly preferably a cyano group or an alkoxycarbonyl group (—C (═O) OR (R is an alkyl group having 1 to 20 carbon atoms, 6 carbon atoms). ~ 12 aryl groups and combinations thereof.

  As the general formula (103), a compound represented by the following general formula (103-A) is preferable.

General formula (103-A)

In general formula (103-A), R < ¹ >, R < ² >, R < ³ >, R < ⁴ >, R < ⁵ >, R < ⁶ >, R < ⁷ >, R <^8> , R < ⁹ > and R < ¹⁰ > each independently represents a hydrogen atom or a substituent. X ¹ and X ² have the same meanings as those in formula (103), and preferred ranges are also the same.

R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ each independently represents a hydrogen atom or a substituent, and the substituent is the above-described substituent T Chosen from. Further, these substituents may be further substituted with another substituent, and the substituents may be condensed to form a ring structure.

R ¹ , R ² , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁹ , and R ¹⁰ are preferably a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a substituted or unsubstituted amino group, An alkoxy group, an aryloxy group, a hydroxy group, and a halogen atom, more preferably a hydrogen atom, an alkyl group, an aryl group, an alkyloxy group, an aryloxy group, and a halogen atom, still more preferably a hydrogen atom and carbon 1-12. An alkyl group, particularly preferably a hydrogen atom or a methyl group, and most preferably a hydrogen atom.

R ³ and R ⁸ are preferably hydrogen atoms, alkyl groups, alkenyl groups, alkynyl groups, aryl groups, substituted or unsubstituted amino groups, alkoxy groups, aryloxy groups, hydroxy groups, halogen atoms, more preferably hydrogen atoms. , An alkyl group having 1 to 20 carbon atoms, an amino group having 0 to 20 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aryloxy group having 6 to 12 carbon atoms, and a hydroxy group, more preferably a hydrogen atom and a carbon number. It is a 1-12 alkyl group and a C1-C12 alkoxy group, Most preferably, it is a hydrogen atom.

  More preferable as the general formula (103) is a compound represented by the following general formula (103-B).

General formula (103-B)

In general formula (103-B), R ³ and R ⁸ have the same meanings as those in general formula (103-A), and preferred ranges are also the same. X ³ represents a hydrogen atom or a substituent.

X ³ represents a hydrogen atom or a substituent, and the substituent can be selected from the above-described substituent T, and may be further substituted with another substituent if possible. X ³ is preferably a hydrogen atom, an alkyl group, an aryl group, a cyano group, a nitro group, a carbonyl group, a sulfonyl group or an aromatic heterocyclic ring, more preferably a cyano group, a carbonyl group, a sulfonyl group or an aromatic heterocyclic ring. More preferably a cyano group or a carbonyl group, and particularly preferably a cyano group or an alkoxycarbonyl group (—C (═O) OR (R is an alkyl group having 1 to 20 carbon atoms, an aryl having 6 to 12 carbon atoms). Group and a combination thereof).

  More preferable as the general formula (103) is a compound represented by the general formula (103-C).

General formula (103-C)

In General Formula (103-C), R ³ and R ⁸ have the same meanings as those in General Formula (103-A), and preferred ranges are also the same. R ²¹ represents an alkyl group having 1 to 20 carbon atoms.

R ²¹ is preferably an alkyl group having 2 to 12 carbon atoms, more preferably an alkyl group having 4 to 12 carbon atoms, and still more preferably 6 carbon atoms when both R ³ and R ⁸ are hydrogen. To 12 alkyl groups, particularly preferably n-octyl group, tert-octyl group, 2-ethylhexyl group, n-decyl group, n-dodecyl group, most preferably 2-ethylhexyl group. It is.

Preferably, when R ³ and R ⁸ are other than hydrogen as R ²¹ , the compound represented by the general formula (103-C) has a molecular weight of 300 or more and an alkyl group having 20 or less carbon atoms. preferable.

  The compound represented by the general formula (103) of the present invention can be synthesized by the method described in Journal of American Chemical Society 63, 3452 (1941).

  Specific examples of the compound represented by the general formula (103) are given below, but the invention is not limited to the following specific examples.

  The cellulose acylate film can be produced in a long shape using various methods such as an extrusion method and a solution casting method. In order to obtain predetermined optical characteristics after being formed into a film, it is desirable to further perform a stretching treatment. When the film is produced by using the solution casting method, a plasticizer (preferably added amount is 0.1 to 20% by mass with respect to the cellulose ester, the same applies hereinafter) and a modifier (0. 1 to 20% by mass), an ultraviolet absorber (0.001 to 10% by mass), a fine particle powder (0.001 to 5% by mass) having an average particle diameter of 5 to 3000 nm, and a fluorosurfactant (0. 001-2 mass%), release agent (0.0001-2 mass%), deterioration inhibitor (0.0001-2 mass%), optical anisotropy control agent (0.1-15 mass%), infrared absorption You may contain additives, such as an agent (0.1-5 mass%). In addition, about the production method of a film, the details are described in the public technique 2001-1745 (issued on March 15,2001, invention association) etc., and can be applied to this invention.

The obtained cellulose acylate film can be appropriately subjected to surface treatment to improve adhesion between the cellulose acylate layer and other layers. The surface treatment includes glow discharge treatment, ultraviolet irradiation treatment, corona treatment, flame treatment, saponification treatment (acid saponification treatment, alkali saponification treatment), and glow discharge treatment and alkali saponification treatment are particularly preferable.
As described above, the first retardation layer is required only for a film containing cellulose acylate containing a substituent having a polarizability anisotropy Δα of 2.5 × 10 ⁻²⁴ cm ⁻³ or more. Although the optical characteristics can be satisfied, the scope of the present invention includes an embodiment in which the first retardation layer includes another birefringent film or retardation film together with the cellulose acylate film.

In the present invention, the second retardation layer may be a layer formed by fixing homeotropic alignment. Examples of the rod-like liquid crystal that can be used for forming the second retardation layer are the same as the compounds exemplified as the rod-like liquid crystal that can be used for forming the first retardation layer. However, in the liquid crystal composition used for forming the second retardation layer, it is preferable to add an alignment aid that promotes homeotropic alignment of the rod-like liquid crystal. A polymer, a fluorine compound, an onium salt and the like are preferable.
Hereinafter, a fluorine-based polymer and an onium salt that can be used for forming the second retardation layer will be described as alignment aids.

  The second retardation layer preferably contains a fluoroaliphatic-containing polymer (hereinafter sometimes referred to as “polymer A”) containing a repeating unit represented by the following general formula (1). The polymer A contributes to vertical alignment of the molecules of the liquid crystal compound mainly at the air interface of the layer.

General formula (1)

In the general formula (1), R ¹ , R ² and R ³ each independently represent a hydrogen atom or a substituent. Q is a carboxyl group (—COOH) or a salt thereof, a sulfo group (—SO ₃ H) or a salt thereof, a phosphonoxy group {—OP (═O) (OH) ₂ } or a salt thereof, or a hydrophilic group (—OH). Represents. L represents an arbitrary group selected from the following linking group group, or a divalent linking group formed by combining two or more thereof.
(Linked group group)
Single bond, —O—, —CO—, —NR ⁴ — (R ⁴ represents a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group), —S—, —SO ₂ —, —P (═O) (OR ⁵ ) — (R ⁵ represents an alkyl group, an aryl group, or an aralkyl group), an alkylene group, and an arylene group.

In the general formula (1), R ¹ , R ² and R ³ each independently represent a hydrogen atom or a substituent selected from the following substituent group exemplified in JP-A-2004-333852.
(Substituent group)
An alkyl group (preferably an alkyl group having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms, such as a methyl group, an ethyl group, an isopropyl group, a tert-butyl group, n-octyl group, n-decyl group, n-hexadecyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group and the like, alkenyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, Particularly preferred are alkenyl groups having 2 to 8 carbon atoms, such as vinyl group, aryl group, 2-butenyl group and 3-pentenyl group), alkynyl groups (preferably having 2 to 20 carbon atoms, more preferred). Is an alkynyl group having 2 to 12 carbon atoms, particularly preferably 2 to 8 carbon atoms, such as propargyl group and 3-pentynyl group. An aryl group (preferably an aryl group having 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as a phenyl group, a p-methylphenyl group, and a naphthyl group. Aralkyl groups (preferably 7 to 30 carbon atoms, more preferably 7 to 20 carbon atoms, particularly preferably 7 to 12 carbon atoms, such as benzyl group, phenethyl group, 3- Phenylpropyl group and the like), a substituted or unsubstituted amino group (preferably an amino group having 0 to 20 carbon atoms, more preferably 0 to 10 carbon atoms, particularly preferably 0 to 6 carbon atoms, Unsubstituted amino group, methylamino group, dimethylamino group, diethylamino group, anilino group, etc.),

An alkoxy group (preferably an alkoxy group having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 10 carbon atoms, and examples thereof include a methoxy group, an ethoxy group, and a butoxy group). An alkoxycarbonyl group (preferably an alkoxycarbonyl group having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 10 carbon atoms such as a methoxycarbonyl group and an ethoxycarbonyl group), acyloxy A group (preferably an acyloxy group having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 10 carbon atoms such as an acetoxy group and a benzoyloxy group), an acylamino group (preferably 2-20 carbon atoms, more preferably 2-16 carbon atoms, particularly preferably 2-10 carbon atoms. A silamino group, for example, an acetylamino group, a benzoylamino group, and the like, an alkoxycarbonylamino group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, and particularly preferably 2 to 12 carbon atoms). An alkoxycarbonylamino group, for example, a methoxycarbonylamino group), an aryloxycarbonylamino group (preferably having 7 to 20 carbon atoms, more preferably 7 to 16 carbon atoms, and particularly preferably 7 to 12 carbon atoms). Aryloxycarbonylamino group, for example, phenyloxycarbonylamino group and the like, sulfonylamino group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 1 carbon atoms). 12 sulfonylamino groups such as methanesulfonyl And sulfamoyl groups (preferably having 0 to 20 carbon atoms, more preferably 0 to 16 carbon atoms, and particularly preferably 0 to 12 carbon atoms, such as sulfamoyl group). Group, methylsulfamoyl group, dimethylsulfamoyl group, phenylsulfamoyl group and the like), carbamoyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and particularly preferably carbon number). 1 to 12 carbamoyl groups, for example, unsubstituted carbamoyl group, methylcarbamoyl group, diethylcarbamoyl group, phenylcarbamoyl group and the like),

An alkylthio group (preferably an alkylthio group having 1 to 20 carbon atoms, more preferably an alkylthio group having 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as a methylthio group and an ethylthio group), an arylthio group ( Preferably it is C6-C20, More preferably, it is C6-C16, Most preferably, it is C6-C12 arylthio group, for example, a phenylthio group etc. are mentioned, A sulfonyl group (preferably C1-C1). 20, more preferably a sulfonyl group having 1 to 16 carbon atoms, particularly preferably a sulfonyl group having 1 to 12 carbon atoms, such as a mesyl group and a tosyl group, and a sulfinyl group (preferably having a carbon number of 1 to 20, more A sulfinyl group having 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms is preferable. Zensulfinyl group and the like), ureido group (preferably a ureido group having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, for example, an unsubstituted ureido group , Methylureido group, phenylureido group, etc.), phosphoric acid amide group (preferably having 1 to 20 carbon atoms, more preferably having 1 to 16 carbon atoms, particularly preferably having 1 to 12 carbon atoms). Yes, for example, diethyl phosphoric acid amide group, phenyl phosphoric acid amide group, etc.), hydroxy group, mercapto group, halogen atom (for example, fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, sulfo group, Carboxyl group, nitro group, hydroxamic acid group, sulfino group, hydrazino group, imino group, heterocyclic group (preferably having a carbon number of 1 to 0, more preferably a heterocyclic group of 1 to 12, for example, a heterocyclic group having a heteroatom such as a nitrogen atom, an oxygen atom, a sulfur atom, such as an imidazolyl group, a pyridyl group, a quinolyl group, a furyl group , Piperidyl group, morpholino group, benzoxazolyl group, benzimidazolyl group, benzthiazolyl group and the like), silyl group (preferably having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, particularly preferably A silyl group having 3 to 24 carbon atoms, and examples thereof include a trimethylsilyl group and a triphenylsilyl group). These substituents may be further substituted with these substituents. Moreover, when it has two or more substituents, they may be the same or different. If possible, they may be bonded to each other to form a ring.

R ¹ , R ² and R ³ are each independently a hydrogen atom, an alkyl group, a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), or a group represented by -LQ described later. It is preferably a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a chlorine atom, or a group represented by -LQ, more preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. More preferably, it is particularly preferably a hydrogen atom or an alkyl group having 1 to 2 carbon atoms, most preferably R ² and R ³ are a hydrogen atom, and R ¹ is a hydrogen atom or a methyl group. Specific examples of the alkyl group include methyl group, ethyl group, n-propyl group, n-butyl group, sec-butyl group and the like. The alkyl group may have a suitable substituent. Examples of the substituent include a halogen atom, aryl group, heterocyclic group, alkoxyl group, aryloxy group, alkylthio group, arylthio group, acyl group, hydroxyl group, acyloxy group, amino group, alkoxycarbonyl group, acylamino group, oxycarbonyl Group, carbamoyl group, sulfonyl group, sulfamoyl group, sulfonamido group, sulfolyl group, carboxyl group and the like. The carbon number of the alkyl group does not include the carbon atom of the substituent. The same applies to the carbon number of other groups.

L represents a divalent linking group selected from the above linking group group, or a divalent linking group formed by combining two or more thereof. In the linking group group, R ^{4 in} —NR ⁴ — represents a hydrogen atom, an alkyl group, an aryl group or an aralkyl group, preferably a hydrogen atom or an alkyl group. R ⁵ in —PO (OR ⁵ ) — represents an alkyl group, an aryl group or an aralkyl group, and preferably an alkyl group. The carbon number when R ⁴ and R ⁵ represent an alkyl group, an aryl group or an aralkyl group is the same as that described in the “substituent group”. L preferably contains a single bond, —O—, —CO—, —NR ⁴ —, —S—, —SO ₂ —, an alkylene group or an arylene group, and is a single bond, —CO—, —O—. , —NR ⁴ —, an alkylene group or an arylene group is particularly preferable, and a single bond is most preferable. When L contains an alkylene group, the alkylene group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably 1 to 6 carbon atoms. Specific examples of particularly preferred alkylene groups include methylene, ethylene, trimethylene, tetrabutylene, hexamethylene groups and the like. When L contains an arylene group, the carbon number of the arylene group is preferably 6 to 24, more preferably 6 to 18, and particularly preferably 6 to 12. Specific examples of particularly preferred arylene groups include phenylene and naphthalene groups. When L contains a divalent linking group (that is, an aralkylene group) obtained by combining an alkylene group and an arylene group, the carbon number of the aralkylene group is preferably 7 to 34, more preferably 7 to 26, and particularly preferably. 7-16. Specific examples of particularly preferred aralkylene groups include a phenylenemethylene group, a phenyleneethylene group, and a methylenephenylene group. The group listed as L may have a suitable substituent. Examples of such a substituent include those similar to the substituents exemplified above as the substituents for R ^{1 to} R ³ .
Although the specific structure of L is illustrated below, this invention is not limited to these specific examples.

  In the formula (1), Q is a carboxyl group, a salt of a carboxyl group (for example, lithium salt, sodium salt, potassium salt, ammonium salt (for example, ammonium, tetramethylammonium, trimethyl-2-hydroxyethylammonium, tetrabutylammonium, trimethyl). Benzylammonium, dimethylphenylammonium, etc.), pyridinium salts, etc.), sulfo groups, salts of sulfo groups (examples of cations forming salts are the same as those described above for carboxyl groups), phosphonoxy groups, salts of phosphonoxy groups Examples of the cation that forms are the same as those described above for the carboxyl group) and a hydrophilic group (hydroxyl group). A carboxyl group, a sulfo group, a phospho group, and a hydrophilic group are more preferable, and a carboxyl group or a hydrophilic group is particularly preferable.

  Although the specific example of the monomer corresponding to the said General formula (1) contained in the said polymer A which can be used for this invention is given below, this invention is not restrict | limited at all by the following specific examples.

  The polymer A may contain one type of repeating unit represented by the general formula (1), or may contain two or more types. The polymer A may have one or more repeating units derived from the fluoroaliphatic group-containing monomer. Preferably, it contains a fluoroaliphatic group-containing monomer described in general formula [1] of JP-A No. 2004-333852. Furthermore, the polymer A may contain other repeating units. The other repeating units are not particularly limited, and preferred examples thereof include repeating units derived from ordinary radical polymerizable monomers. The polymer A may contain one type of repeating unit derived from a monomer selected from the monomer group described in JP-A-2004-46038 [0026] to [0033], or may contain two or more types. Good.

  The polymer A may contain a repeating unit derived from a monomer represented by the general formula [2] described in JP-A-2004-333852.

  The amount of the fluoroaliphatic group-containing monomer of the polymer A is preferably 5% by mass or more, more preferably 10% by mass or more, and more preferably 30% by mass or more of the total amount of constituent monomers of the polymer. Further preferred. In the repeating unit derived from the fluoroaliphatic group-containing monomer, the amount of the repeating unit represented by the general formula (1) is 0 of the total amount of constituent monomers of the repeating unit derived from the fluoroaliphatic group-containing monomer. It is preferably 5% by mass or more, more preferably 1 to 20% by mass, particularly preferably 1 to 10% by mass, and most preferably 1 to 5% by mass.

  The mass average molecular weight of the polymer A used in the present invention is preferably 1,000,000 or less, more preferably 500,000 or less, and further preferably 5,000 or more and 50,000 or less. The mass average molecular weight can be measured as a value in terms of polystyrene (PS) using gel permeation chromatography (GPC).

  The polymerization method employed when producing the polymer A is not particularly limited, but the method described in [0035] to [0041] of JP-A No. 2004-46038 is preferably used.

  The polymer A preferably has a polymerizable group as a substituent in order to fix the alignment state of the rod-like liquid crystal compound.

  Specific examples that are preferably used in the present invention as the polymer A are shown below, but the present invention is not limited to these specific examples. Here, the numerical values (numerical values such as a, b, c, and d) in the formula are mass percentages indicating the composition ratio of each monomer, and Mw is TSK Gel GMHxL, TSK Gel G4000 HxL, TSK Gel G2000 HxL (whichever Also, the mass average molecular weight is expressed in terms of polystyrene by solvent THF and differential refractometer detection using a GPC analyzer using a column of Tosoh Corporation's trade name).

  The polymer A used in the present invention can be produced by a known and commonly used method as described above. For example, it can be produced by adding a general-purpose radical polymerization initiator to an organic solvent containing the above-mentioned monomer having a fluoroaliphatic group, a monomer having a hydrogen bonding group, and the like, and polymerizing the mixture. Further, in some cases, other addition-polymerizable unsaturated compounds can be further added and produced by the same method as described above. Depending on the polymerizability of each monomer, a dropping polymerization method in which a monomer and an initiator are added dropwise to a reaction vessel is also effective for obtaining a polymer having a uniform composition.

  The preferable range of the content of the polymer A in the second retardation layer forming composition varies depending on the use, but 0.005 in the composition (a composition excluding the solvent in the case of a coating solution). It is preferably -8% by mass, more preferably 0.01-5% by mass, and further preferably 0.05-1% by mass. If the amount of the repeating unit derived from the fluoroaliphatic group-containing monomer is less than 0.005% by mass, the effect is insufficient, and if it exceeds 8% by mass, the coating film may not be sufficiently dried. The performance as an optical compensation film (for example, uniformity of retardation, etc.) may be adversely affected.

[Onium salt]
The second retardation layer preferably contains at least one onium salt. The onium salt contributes to the vertical alignment of the molecules of the rod-like liquid crystal compound on the alignment film interface side. Examples of the onium salts include ammonium salts containing nitrogen atoms, sulfonium salts containing sulfur atoms, phosphonium salts containing phosphorus atoms, and the like.

The onium salt is preferably a quaternary onium salt, more preferably a quaternary ammonium salt.
A quaternary ammonium salt is generally a tertiary amine (eg, trimethylamine, triethylamine, tributylamine, triethanolamine, N-methylpyrrolidine, N-methylpiperidine, N, N-dimethylpiperazine, triethylenediamine, N, N , N ′, N′-tetramethylethylenediamine, etc.) or nitrogen-containing heterocycle (pyridine ring, picoline ring, 2,2′-bipyridyl ring, 4,4′-bipyridyl ring, 1,10-phenanthroline ring, quinoline ring, An oxazole ring, a thiazole ring, an N-methylimidazole ring, a pyrazine ring, a tetrazole ring, and the like) are obtained by alkylation (Mentstock reaction), alkenylation, alkynylation, or arylation.

As the quaternary ammonium salt, a quaternary ammonium salt composed of a nitrogen-containing heterocyclic ring is preferable, and a quaternary pyridinium salt is particularly preferable.
More specifically, the quaternary ammonium salt is preferably selected from quaternary pyridinium salts represented by the following general formula (3a) or a general formula (3b) described later.

In the formula (3a), R ⁸ represents a substituted or unsubstituted alkyl group, alkenyl group, alkynyl group, aralkyl group, aryl group or heterocyclic group, D represents a hydrogen bonding group, and m represents 1 to 3 X ⁻ represents an anion.

First, the general formula (3a) will be described.
The alkyl group represented by R ⁸ is preferably a substituted or unsubstituted alkyl group having 1 to 18 carbon atoms, and more preferably a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms. These may be linear, branched or cyclic. Examples of these are methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-hexyl, n-octyl, neopentyl, cyclohexyl, adamantyl. Group and cyclopropyl group.

  Examples of the substituent of the alkyl group include the following. C2-C18 (preferably C2-C8) substituted or unsubstituted alkenyl group (for example, vinyl group); C2-C18 (preferably C2-8) substituted or unsubstituted alkynyl Group (for example, ethynyl group); substituted or unsubstituted aryl group having 6 to 10 carbon atoms (for example, phenyl group, naphthyl group); halogen atom (for example, F, Cl, Br, etc.); Preferably a substituted or unsubstituted alkoxy group having 1 to 8 carbon atoms (for example, methoxy group or ethoxy group); a substituted or unsubstituted aryloxy group having 6 to 10 carbon atoms (for example, phenoxy group, biphenyloxy group, p-methoxyphenoxy group); substituted or unsubstituted alkylthio group having 1 to 18 carbon atoms (preferably 1 to 8 carbon atoms) (for example, methylthio group, ethylthio group) A substituted or unsubstituted arylthio group having 6 to 10 carbon atoms (for example, phenylthio group); a substituted or unsubstituted acyl group having 2 to 18 carbon atoms (preferably 2 to 8 carbon atoms) (for example, an acetyl group or a propionyl group) );

  C1-C18 (preferably C1-C8) substituted or unsubstituted alkylsulfonyl group or arylsulfonyl group (for example, methanesulfonyl group, p-toluenesulfonyl group); C2-C18 (preferably carbon) A substituted or unsubstituted acyloxy group (for example, acetoxy group, propionyloxy group) having 2 to 8 carbon atoms; a substituted or unsubstituted alkoxycarbonyl group having 2 to 18 carbon atoms (preferably having 2 to 8 carbon atoms) (for example, A methoxycarbonyl group, an ethoxycarbonyl group); a substituted or unsubstituted aryloxycarbonyl group having 7 to 11 carbon atoms (for example, a naphthoxycarbonyl group); an unsubstituted amino group, or a carbon number of 1 to 18 (preferably having a carbon number) 1-8) substituted amino groups (for example, methylamino group, dimethylamino group, diethylamino group) Anilino group, methoxyphenylamino group, chlorophenylamino group, pyridylamino group, methoxycarbonylamino group, n-butoxycarbonylamino group, phenoxycarbonylamino group, methylcarbamoylamino group, ethylthiocarbamoylamino group, phenylcarbamoylamino group, acetylamino Group, ethylcarbonylamino group, ethylthiocarbamoylamino group, cyclohexylcarbonylamino group, benzoylamino group, chloroacetylamino group, methylsulfonylamino group);

  C1-C18 (preferably C1-C8) substituted or unsubstituted carbamoyl group (for example, unsubstituted carbamoyl group, methylcarbamoyl group, ethylcarbamoyl group, n-butylcarbamoyl group, tert-butylcarbamoyl group) , Dimethylcarbamoyl group, morpholinocarbamoyl group, pyrrolidinocarbamoyl group); unsubstituted sulfamoyl group, or substituted sulfamoyl group having 1 to 18 carbon atoms (preferably 1 to 8 carbon atoms) (for example, methylsulfamoyl group, phenyl) Cyano group; nitro group; carboxy group; hydroxyl group; heterocyclic group (for example, oxazole ring, benzoxazole ring, thiazole ring, benzothiazole ring, imidazole ring, benzimidazole ring, indolenine ring, pyridine ring) , Piperidine ring, pyro Jin ring, morpholine ring, sulfolane ring, furan ring, thiophene ring, pyrazole ring, pyrrole ring, chroman ring, a coumarin ring). The substituent for the alkyl group is particularly preferably an aryloxy group, an arylthio group, an arylsulfonyl group, or an aryloxycarbonyl group.

The alkenyl group represented by R ⁸ is preferably a substituted or unsubstituted alkenyl group having 2 to 18 carbon atoms, more preferably a substituted or unsubstituted alkenyl group having 2 to 8 carbon atoms, such as a vinyl group. , Allyl group, 1-propenyl group, 1,3-butadienyl group and the like.
As the substituent for the alkenyl group, those exemplified as the substituent for the alkyl group are preferable.

The alkynyl group represented by R ⁸ is preferably a substituted or unsubstituted alkynyl group having 2 to 18 carbon atoms, more preferably a substituted or unsubstituted alkynyl group having 2 to 8 carbon atoms, such as an ethynyl group. , 2-propynyl and the like. As the substituent for the alkynyl group, those exemplified as the substituent for the alkyl group are preferable.

The aralkyl group represented by R ⁸ is preferably a substituted or unsubstituted aralkyl group having 7 to 18 carbon atoms, such as a benzyl group, a methylbenzyl group, a biphenylmethyl group, or a naphthylmethyl group. Examples of the substituent for the aralkyl group include those exemplified as the substituent for the alkyl group.

The aryl group represented by R ⁸ is preferably a substituted or unsubstituted aryl group having 6 to 18 carbon atoms, and examples thereof include a phenyl group, a naphthyl group, and a fluorenyl group. As the substituent for the aryl group, those exemplified as the substituent for the alkyl group are preferable. Besides these, an alkyl group (for example, a methyl group, an ethyl group, etc.), an alkynyl group, and a benzoyl group are also preferable.

The heterocyclic group represented by R ⁸ is a 5- or 6-membered saturated or unsaturated heterocyclic ring composed of a carbon atom, a nitrogen atom, an oxygen atom or a sulfur atom, and examples thereof include oxazole Ring, benzoxazole ring, thiazole ring, benzothiazole ring, imidazole ring, benzimidazole ring, indolenine ring, pyridine ring, piperidine ring, pyrrolidine ring, morpholine ring, sulfolane ring, furan ring, thiophene ring, pyrazole ring, pyrrole ring , Chroman ring, and coumarin ring. The heterocyclic group may be substituted, and as the substituent in that case, those exemplified as the substituent of the alkyl group are preferable. As the heterocyclic group represented by R ⁸ , a benzoxazole ring and a benzothiazole ring are particularly preferable.

R ⁸ is preferably a substituted or unsubstituted alkyl group, aralkyl group, aryl group or heterocyclic group.

  D represents a hydrogen bonding group. Hydrogen bonds exist between electronegative atoms (eg, O, N, F, Cl) and hydrogen atoms covalently bonded to electronegative atoms as well. As a theoretical interpretation of hydrogen bonding, for example, H.H. Unneyama and K.M. There are reports in Morokuma, Journal of American Chemical Society, Vol. 99, pp. 1316-1332, 1977. Specific examples of hydrogen bonding include J.I. N. Examples include Israes Ativiri, Yasuo Kondo, Hiroyuki Oshima, Intermolecular Force and Surface Force, McGraw Hill, 1991, page 98, FIG. Specific examples of hydrogen bonding include, for example, G.I. R. Examples include those described in Desiraju, Angewent Chemistry International Edition England, Vol. 34, p. 2311, 1995.

  Preferred hydrogen bonding groups include mercapto groups, hydroxy groups, amino groups, carbonamido groups, sulfonamido groups, acid amide groups, ureido groups, carbamoyl groups, carboxyl groups, sulfo groups, nitrogen-containing heterocyclic groups (for example, imidazolyl). Group, benzimidazolyl group, pyrazolyl group, pyridyl group, 1,3,5-triazyl group, pyrimidyl group, pyridazyl group, quinolyl group, benzimidazolyl group, benzthiazolyl group, succinimide group, phthalimide group, maleimide group, uracil group, thiouracil Group, barbituric acid group, hydantoin group, maleic hydrazide group, isatin group, uramil group and the like. More preferred hydrogen bonding groups include amino group, carbonamido group, sulfonamido group, ureido group, carbamoyl group, carboxyl group, sulfo group, and pyridyl group, and particularly preferred are amino group, carbamoyl group, A pyridyl group can be mentioned.

The anion represented by X ⁻ may be either an inorganic anion or an organic anion, such as a halogen anion (eg, fluorine ion, chlorine ion, bromine ion, iodine ion), sulfonate ion (eg, methanesulfone). Acid ion, trifluoromethanesulfonic acid ion, methylsulfuric acid ion, p-toluenesulfonic acid ion, p-chlorobenzenesulfonic acid ion, 1,3-benzenedisulfonic acid ion, 1,5-naphthalenedisulfonic acid ion, 2,6-naphthalene Disulfonate ion, etc.), sulfate ion, thiocyanate ion, perchlorate ion, tetrafluoroborate ion, picrate ion, acetate ion, phosphate ion (for example, hexafluorophosphate ion), hydroxide ion, etc. .
X ⁻ is preferably a halogen anion, a sulfonate ion, or a hydroxide ion. X ⁻ need not be a monovalent anion and may be a divalent or higher anion. In such a case, the ratio of the cation to the anion in the compound need not be 1: 1, It is determined.

  In the general formula (3a), m is preferably 1.

Next, the general formula (3b) will be described.

In formula (3b), R ⁹ and R ¹⁰ each represents a substituted or unsubstituted alkyl group, alkenyl group, alkynyl group, aralkyl group, aryl group or heterocyclic group, and X ⁻ represents an anion.
The substituted or unsubstituted alkyl group, alkenyl group, alkynyl group, aralkyl group, aryl group or heterocyclic group represented by R ⁹ and R ¹⁰ respectively is represented by R ⁸ in the general formula (3a). It is synonymous with a group, and its preferable range is also the same. X ^- anion represented by the In the general formula (3a), X ^- has the same meaning as anion represented by, and the preferable ranges thereof are also the same. As described above, X ⁻ need not be a monovalent anion but may be a divalent or higher anion. In such a case, the ratio of the cation to the anion in the compound should be 1: 2. It is not determined.

  Specific examples of the quaternary pyridinium salt represented by the general formula (3a) or (3b) and other onium salts preferably used in the present invention are shown below, but the onium salts used in the present invention are shown below. It is not limited.

  The preferable content of the onium salt in the second retardation layer varies depending on the type, but is usually 0.01 to 10% by mass with respect to the content of the liquid crystal compound used in combination. It is preferable that it is 0.05-7 mass%, and it is still more preferable that it is 0.05-5 mass%. Two or more kinds of onium salts may be used. In such a case, the total content of all kinds of onium salts to be used is preferably within the above range.

  When the second retardation layer is formed from a liquid crystal composition, a support made of a polymer film or the like that supports the second retardation layer may be required. The support may be, for example, a protective film for a polarizing film. Such a protective film is preferably an optically isotropic film having almost zero retardation. For example, a cellulose acylate film described in JP-A-2005-138375 is preferable.

The present invention will be described more specifically with reference to the following examples. The materials, reagents, amounts and ratios of substances, operations, and the like shown in the following examples can be appropriately changed without departing from the gist of the present invention. Therefore, the scope of the present invention is not limited to the following specific examples.
[Example 1]
An ECB mode liquid crystal display device having the same configuration as that of FIG. 1 was produced.
(Production of ECB mode liquid crystal cell)
The liquid crystal cell had a cell gap of 3.28 μm, a liquid crystal material having a positive dielectric constant anisotropic layer was sealed between the substrates by vacuum injection, and Δn · d of the liquid crystal layer was 280 nm. The liquid crystal material has a positive dielectric anisotropy, a refractive index anisotropy, and a liquid crystal having Δn = 0.0854 (589 nm, 20 ° C.) and Δε = + 8.5 (for example, MLC-9100 manufactured by Merck) is used. did. In addition, the liquid crystal alignment is rubbed so as to be homogeneous alignment, and after forming the liquid crystal cell, the upper and lower substrate rubbing direction (alignment control direction) of the liquid crystal cell is the slow axis of the protective film (casting). Direction parallel to the direction) and 45 °.

(Preparation of cellulose acylate film for protective film)
According to the following synthesis example, the polarizability anisotropy defined by the above formula (A) is 8.8 by reaction with a corresponding acid chloride using cellulose acetate (acetyl substitution degree: 2.45) manufactured by Aldrich as a starting material. A cellulose acylate 1 of 6 × 10 ⁻²⁴ cm ⁻³ was obtained. In addition, you may use the cellulose acetate (Acetyl substitution degree 2.41 (brand name: L-70), 2.14 (brand name: LM-80)) by Daicel Corporation as a starting material.

-Synthesis of Asalonic Acid Chloride Weigh 106.1 g of Asaronic acid (2,4,5-trimethoxybenzoic acid) and 400 ml of toluene into a 1 L three-necked flask equipped with a mechanical stirrer, thermometer, condenser, and dropping funnel, and 80 ° C. And stirred. 40.1 mL of thionyl chloride was slowly added dropwise thereto, and after addition, the mixture was further stirred at 80 ° C. for 2 hours. After the reaction, when the reaction solvent was distilled off using an aspirator, a white solid was obtained. To the obtained white solid, 300 ml of hexane was added, and the mixture was vigorously stirred and dispersed. The white solid was separated by suction filtration, and further washed with a large amount of hexane three times. The obtained white solid was vacuum-dried at 60 ° C. for 4 hours to obtain the target asaronic acid chloride as a white powder. (115.3 g, 99% yield)

-Synthesis of cellulose acylate 1 Into a 1 L three-necked flask equipped with a mechanical stirrer, thermometer, condenser, and dropping funnel, 40 g of cellulose acetate (acetyl substitution degree 2.45) made by Aldrich, 46.0 ml of pyridine, and 300 ml of methylene chloride. Weighed out and stirred at room temperature. Here, 84.0 g of the synthesized asaronic acid chloride was divided into several portions and added in powder form. After the addition, the mixture was further stirred at room temperature for 6 hours. After the reaction, when the reaction solution was added to 4 L of methanol with vigorous stirring, a white pink solid was precipitated. The white peach colored solid was separated by suction filtration and washed three times with a large amount of methanol. The obtained white pink solid was dried at 60 ° C. overnight and then vacuum dried at 90 ° C. for 6 hours to obtain the target compound as a white pink powder. For the obtained sample, cellulose acylate 1, the degree of substitution was determined from the peak intensity of the carbonyl carbon in the acyl group in C ¹³ -NMR. Cellulose acylate 1 containing a substituent having a polarizability anisotropy Δα defined by the formula (A) Δα = αx− (αy + αz) / 2 was 8.6 × 10 ⁻²⁴ cm ⁻³ was obtained. This cellulose acylate 1 had a total acyl group substitution degree (PA) of 2.91 and an aromatic acyl group substitution degree of 0.46.

After the cellulose acylate 1 produced above was dried at 120 ° C. for 2 hours, the composition described below was put into a mixing tank, stirred while heating to dissolve each component, and a cellulose acylate solution was prepared. Prepared.
====================================
Methylene chloride 261 parts by mass Methanol 39 parts by mass Triphenyl phosphate 5.9 parts by mass Biphenyl diphenyl phosphate 5.9 parts by mass Cellulose acylate 1 100 parts by mass Silicon dioxide fine particles 0.25 parts by mass ======== ============================

The mixing tank used was a 400-liter stainless steel tank having stirring blades and circulating cooling water around the outer periphery. The solvent and additives other than cellulose acylate were added and stirred to disperse or dissolve, and then the cellulose acylate was gradually added. After completion of the addition, the mixture was stirred at room temperature for 2 hours, swollen for 3 hours, and then stirred again.
For stirring, a dissolver type eccentric stirring shaft that stirs at a peripheral speed of 15 m / sec (shear stress 5 × 10 ⁴ kgf / m / sec ² ) and an anchor blade on the central axis and a peripheral speed of 1 m / sec. A stirring shaft that stirs at a sec (shear stress of 1 × 10 ⁴ kgf / m / sec ² ) was used. Swelling was carried out with the high speed stirring shaft stopped and the peripheral speed of the stirring shaft having anchor blades set at 0.5 m / sec.
The cellulose acylate solution thus obtained was filtered with a filter paper having an absolute filtration accuracy of 0.01 mm (# 63, manufactured by Toyo Filter Paper Co., Ltd.), and further filtered with an absolute filtration accuracy of 2.5 μm (FH025, Paul Corporation). To obtain a cellulose acylate solution.

The cellulose acylate solution was heated to 30 ° C., and cast on a mirror-surface stainless steel support having a band length of 60 m through a casting Giesser (described in JP-A-11-314233). The casting point was set on a roll set at 18 ° C., and the temperature of the other roll supporting the band was set at 35 ° C. Moreover, the space temperature of the whole casting part was set to 80 degreeC. The casting speed was 40 m / min and the coating width was 140 cm.
The cellulose acylate film which had been cast and rotated 50 cm before the cast part was peeled off from the band, and both ends of the film were gripped with a tenter. The tenter part at 110 ° C. was conveyed while the film width was gradually narrowed, and was released from the tenter so as to be 98% of the width when the film was gripped. After the clip traces at both ends of the film were cut off, the film was dried through a film at 135 ° C. to 140 ° C. consisting of a plurality of pass rolls so that the residual solvent amount was 0.2% or less. Thus, a long cellulose acylate film 1 having a thickness of 90 μm was obtained.
About the obtained cellulose acylate film 1, the optical incident angle dependency of retardation was measured using an automatic birefringence meter (KOBRA-21ADH, manufactured by Oji Scientific Instruments), and optical characteristics were calculated. . The results are shown in the following table.

In the production of the cellulose acylate film, Re (550) and / or except that the cellulose acylate used as a raw material was changed and / or the film forming conditions such as the draw ratio and the film thickness were changed. Various cellulose acylate films having different Rth (550) were produced in a long shape. Table 1 shows Re (550) and Rth (550) of the produced cellulose acylate films 1 to 17. For reference, the optical properties of FUJITAC TD80UL (manufactured by FUJIFILM Corporation) used in Comparative Examples described later are also shown in Table 1.
Among the produced cellulose acylate films 1 to 7, it can be understood that the cellulose acylate films 1 to 5 satisfy the optical characteristics as the second retardation layer. In addition, all the cellulose acylate films 1-5 were the films produced using the said synthesized cellulose acylate 1 as a raw material.

(Formation of first retardation layer)
After one saponified surface of each cellulose acylate film prepared in the above, the film while conveying the, an alignment film coating solution having the following composition on the film was 20 ml / m ² coated with a wire bar coater. The film was formed by drying with warm air of 60 ° C. for 60 seconds and further with warm air of 100 ° C. for 120 seconds. Next, the formed film was rubbed to obtain an alignment film. At this time, the rubbing angle with respect to the film transport direction needs to be rubbed so that the liquid crystal molecular major axis is aligned in the 45 ° azimuth direction with respect to the film MD direction (longitudinal direction). Usually, in order to realize 45 ° orientation, it is necessary to rub in an orientation of 45 ° or more with respect to the transport direction.
Composition of alignment film coating solution Modified polyvinyl alcohol 10 parts by weight Water 371 parts by weight Methanol 119 parts by weight Glutaraldehyde 0.5 parts by weight

Modified polyvinyl alcohol

A coating solution for forming a retardation layer having the following composition was prepared.
Coating composition for retardation layer formation ―――――――――――――――――――――――――――――――――
The following rod-like liquid crystal compound 38.4% by mass
The following sensitizer 0.38 mass%
The following photopolymerization initiator 1.15% by mass
The following air interface horizontal alignment agent 0.06 mass%
Methyl ethyl ketone 60.0 mass%
―――――――――――――――――――――――――――――――――

The coating solution was continuously applied to the surface of the alignment film using a bar coater. The coating layer was heated at 100 ° C. for 1 minute to align the rod-like liquid crystal molecules, and then irradiated with ultraviolet rays to polymerize the rod-like liquid crystal molecules, and the alignment state was fixed to form a retardation layer.
The formed retardation layer had a thickness of 3.5 μm and Re (550) was 280 nm. In this manner, laminated films 101 to 107 each having a retardation layer were produced on each surface of the cellulose acylate film produced above.
Further, a laminated film 108 in which a retardation layer was formed on the surface of Fujitac TD80UL (manufactured by FUJIFILM Corporation) by the same method as described above was produced.

(Preparation of polarizing plate)
As a display surface side polarizing plate, Fujitac TD80UL (manufactured by FUJIFILM Corporation) is attached to one surface of a polyvinyl alcohol polarizing film, and each of the prepared cellulose acylate films 1 to 7, or Fujitac TD80UL is attached to the other surface. Each of the polarizing plates 201A to 208A produced by pasting was used.
In addition, as a backlight side polarizing plate, Fujitac TD80UL (manufactured by FUJIFILM Corporation) is attached to one surface of a polyvinyl alcohol-based polarizing film, and each of the laminated films 101 to 108 prepared on the other surface is bonded to cellulose acylate. Each of the polarizing plates 201B to 208B produced by pasting the rate film side with the polarizing film side was used.

The EBC mode liquid crystal cell prepared above is sandwiched between the display surface side polarizing plates 201A to 208A prepared above and the backlight side polarizing plates 201B to 208B facing each other, and is the same as FIG. The ECB mode liquid crystal display devices 301 to 308 having the configuration were manufactured. In FIG. 1, the absorption axes of the display surface side and backlight side polarizing films 12a and 12b intersect the alignment direction of the liquid crystal cell 18 (the rubbing direction of the substrate surface) at about 45 °, and the plates of the polarizing films 12a and 12b. The crossing angle of the absorption axes was approximately 90 ° orthogonal Nicol. In addition, the slow axis of the first retardation layer 16 was set to a direction orthogonal to the average alignment direction of the major axes of the liquid crystal molecules in the liquid crystal cell 18 in the state where no voltage was applied.
For each of the manufactured liquid crystal display devices 301 to 308 in each ECB mode, the brightness of contrast (CR; no voltage application state (black display) and voltage application state (white display) is changed by changing the viewing angle vertically and horizontally. Ratio), and the total of the viewing angle azimuths in the upper, lower, left, and right directions with CR> 10 was calculated. The results are shown in Table 2 below.

From the results shown in Table 2, in the ECB mode liquid crystal display device having the configuration shown in FIG. 1, an example using the cellulose acylate film satisfying the formula (1) as the protective films 14 a and 14 b (liquid crystal display devices 301 to 301) 305), it was found that the display ability of CR> 10 can be obtained in a wide viewing angle (total of top and bottom and left and right is 240 degrees or more). The effect was remarkable compared with the comparative example (liquid crystal display device 306-308) which used the cellulose acylate film which does not satisfy Formula (1) as protective film 14a, 14b.
Further, when cellulose acylate films having different Re (550) are used as the protective films 14a and 14b by changing the stretching conditions for the cellulose acylate films 1 to 5, the contrast of the liquid crystal display device having the configuration of FIG. When Re (550) is within the range of 0 to 130 nm, the total viewing angle of CR> 10 exceeds 240 degrees, and a high-contrast image display ability can be obtained over a wide viewing angle. I confirmed. Further, it was found that when the cellulose acylate film satisfies −200 nm ≦ Rth ≦ 0 nm, the dependency of viewing angle characteristics on Re (550) of the cellulose acylate film is further reduced.
In particular, the region of −50 ≦ Rth (550) ≦ −150 and 0 ≦ Re (550) ≦ 130 is particularly excellent, and more specifically, the total viewing angle of the upper, lower, left, and right viewing angles at which CR> 10 is obtained. Was found to exceed 320 degrees.

[Example 2]
In Example 1, as the protective films 14a and 14b in FIG. 1, polymer films produced by stretching a polycarbonate resin, a polyester resin, and a resin having a norbornene skeleton, in which Rth satisfies the above formula (1), respectively. , It was found that the same effects as in Example 1 can be obtained even if each is used.

[Example 3]
In Example 1, the laminated films produced as follows were used as the protective films 14a and 14b in FIG.
First, according to the Example described in JP-A-2005-138375, a cellulose acylate film F1 having almost zero retardation was produced.
The cellulose acetate film F1 was subjected to a surface saponification treatment, and an alignment film coating solution having the following composition was coated on the surface thereof with a wire bar coater at 20 ml / m ² . A film was formed by drying with warm air of 60 ° C. for 60 seconds and further with warm air of 100 ° C. for 120 seconds to obtain an alignment film.
Composition of alignment film coating liquid Modified polyvinyl alcohol 10 parts by weight Water 371 parts by weight Methanol 119 parts by weight Glutaraldehyde 0.5 parts by weight

Modified polyvinyl alcohol

  A coating solution containing a rod-like liquid crystal compound having the following composition was continuously applied onto the prepared alignment film with a # 5.0 wire bar. The conveyance speed of the film was 20 m / min. The solvent was dried in a step of continuously heating from room temperature to 80 ° C., and then heated in a drying zone at 80 ° C. for 90 seconds to align the rod-like liquid crystal compound. Subsequently, the temperature of the film was maintained at 80 ° C., the orientation of the liquid crystal compound was fixed by UV irradiation, and a first retardation layer was formed. Subsequently, the film prepared in a 1.5 mol / L sodium hydroxide aqueous solution at 55 ° C. was immersed for 2 minutes, and then immersed in water to sufficiently wash away sodium hydroxide. Then, after being immersed for 1 minute in 5 mmol / L sulfuric acid aqueous solution of 35 degreeC, it was immersed in water and the dilute sulfuric acid aqueous solution was fully washed away. Finally, the sample was thoroughly dried at 120 ° C. In this way, a laminated film 120 in which the retardation layer was laminated on the cellulose acylate film F1 was produced. Moreover, it was 0.61% when the haze measurement was performed with the Nippon Denshoku Industries Co., Ltd. haze meter (NDH-2000).

Composition of coating liquid containing rod-shaped liquid crystal compound ――――――――――――――――――――――――――――――――――――
The following rod-like liquid crystalline compound 100 parts by mass Photopolymerization initiator (Irgacure 907, manufactured by Ciba Geigy) 3 parts by mass Sensitizer (Kayacure DETX, manufactured by Nippon Kayaku Co., Ltd.) 1 part by mass The following polymer A 0.2 Part by mass The following onium salt (21) 1 part by mass Methyl ethyl ketone 172 parts by mass ――――――――――――――――――――――――――――――――― -

  Only the retardation layer containing the rod-shaped liquid crystalline compound was peeled from the produced laminated film 120, and the optical characteristics were measured using an automatic birefringence meter (KOBRA-21ADH, manufactured by Oji Scientific Instruments). Re of only the retardation layer measured at a wavelength of 590 nm was 0 nm, and Rth was −100 nm. That is, it was confirmed that a layer satisfying the formulas (1) and (2) required for the second retardation layer was formed. It was also confirmed that a retardation layer in which rod-like liquid crystal molecules were aligned substantially perpendicular to the layer surface was formed.

  As a polarizing plate on the display surface side, a polarizing plate 220A prepared by attaching Fujitac TD80UL (manufactured by FUJIFILM) on one surface of a polyvinyl alcohol polarizing film and attaching the laminated film 120 prepared on the other surface. An ECB mode liquid crystal display device was produced in the same manner as in Example 1 except that was used, and evaluated in the same manner to confirm that the same effect as in Example 1 was obtained.

[Example 4]
Each of the above-prepared polarizing plates 201B to 205B and B is used as the backlight side polarizing plate in the same configuration as in FIG. 2, except that the polarizing plate 208A is used as the polarizing plate on the display surface side. Although a liquid crystal display device was produced using a combination of the above, a display performance with a sufficiently wide viewing angle was shown although it was slightly inferior to Example 1.
The same configuration as that of FIG. 3, that is, each of the above-prepared polarizing plates 201 </ b> A to 205 </ b> A is used as the polarizing plate on the display surface side, but in any case, the polarizing plate 208 </ b> B is combined as the polarizing plate on the backlight side. Each of the liquid crystal display devices was fabricated, and although it was slightly inferior to Example 1, it exhibited a display capability with a sufficiently wide viewing angle.

Each of the above-prepared polarizing plates 201A to 205A was used as the polarizing plate on the display surface side, that is, the polarizing plate 201B 'to 205B' as the backlight side polarizing plate. Specifically, the polarizing plates 201B ′ to 205B ′ are polarized on the first retardation layer side when the laminated films 101 to 105 are bonded to the polyvinyl alcohol polarizing film in the production of the polarizing plates 201B to 205B. The polarizing plates are bonded to each other on the film surface side, and the other methods are the same as the manufacturing methods of the polarizing plates 201B to 205B.
It was confirmed that the same effects as in Example 1 were obtained when the polarizing plates 201B ′ to 205B ′ were used as the display surface side polarizing plate.

It is a cross-sectional schematic diagram of an example of the liquid crystal display device of this invention. It is a cross-sectional schematic diagram of the other example of the liquid crystal display device of this invention. It is a cross-sectional schematic diagram of the other example of the liquid crystal display device of this invention. It is a cross-sectional schematic diagram of the other example of the liquid crystal display device of this invention.

Explanation of symbols

12a, 12b Polarizing film 14a, 14b, 15a, 15b Protective film (second retardation layer)
14b 'second retardation layer 16 first retardation layer 18 liquid crystal cell

Claims (7)

First and second substrates disposed opposite to each other and at least one of which has a transparent electrode; a liquid crystal molecule between the first and second substrates without a voltage applied, and a twist angle of 45 ° between the substrates A liquid crystal layer that is aligned substantially parallel to the substrate surface and in which a liquid crystal molecule is aligned in a normal direction of the substrate surface when a voltage is applied; and a liquid crystal layer that is disposed across the liquid crystal layer and has orthogonal polarization axes A first retardation layer between the first and / or second polarizing layer and the liquid crystal layer; and the first and / or second polarizing layer and the liquid crystal. A liquid crystal display device having a second retardation layer between the layers,
The first retardation layer is a layer formed by curing a liquid crystal composition containing a rod-like liquid crystal compound, and the in-plane slow axis of the layer is a liquid crystal in the liquid crystal layer in a state in which no voltage is applied. In the direction perpendicular to the average orientation direction of the major axis of the molecule,
The in-plane slow axis of the second retardation layer is parallel or orthogonal to the absorption axis of the first or second polarizing layer disposed closer to the layer, and the thickness direction of the layer at a wavelength of 550 nm The retardation Rth (550) of the liquid crystal display device satisfies the following formula (1):
(1) −200 nm <Rth (550) <0 nm. 2. The liquid crystal display device according to claim 1, wherein Rth (550) of the second retardation layer satisfies the following formula (1) ′:
(1) ′ −150 nm ≦ Rth (550) ≦ −70 nm. The in-plane retardation Re of the first retardation layer and the effective retardation in the panel normal direction of the liquid crystal layer during black display are substantially equal at a wavelength of 550 nm. Liquid crystal display device. The in-plane slow axis of the second retardation layer is substantially parallel to the absorption axis of the first or second polarizing layer disposed closer to the layer, and the in-plane at a wavelength of 550 nm of the layer Retardation Re (550) satisfies following formula (2), The liquid crystal display device of any one of Claims 1-3 characterized by the above-mentioned:
(2) 0 nm ≦ Re (550) ≦ 130 nm. 5. The first retardation phase is formed by curing a curable composition containing at least one rod-like liquid crystal compound having two or more photopolymerizable functional groups. The liquid crystal display device according to any one of the above. From the film in which the second retardation layer contains a cellulose acylate containing a substituent having a polarizability anisotropy Δα represented by the following formula (A) of 2.5 × 10 ⁻²⁴ cm ⁻³ or more. The liquid crystal display device according to any one of claims 1 to 5:
Δα = αx− (αy + αz) / 2 (A)
In the formula, αx, αy, and αz are eigenvalues obtained after diagonalizing the polarizability tensor and satisfy αx ≧ αy ≧ αz. The second retardation layer is formed by curing a curable composition containing at least one kind of rod-like liquid crystal compound having two or more photopolymerizable functional groups. The liquid crystal display device according to any one of the above.

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