JP2003262728A - Optical retardation plate and circularly polarizing plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical retardation plate which is easily and stably manufactured and a circularly polarizing plate. <P>SOLUTION: The optical retardation plate comprises a first optically anisotropic layer consisting of a vertically aligned discotic liquid crystal compound with π phase difference and a second optically anisotropic layer consisting of a vertically aligned discotic liquid crystal compound with π/2 phase difference laminated to each other and is characterized in that the discotic liquid crystal compound of the first optically anisotropic layer is aligned by a liquid crystal alignment layer so as to have the optic axis in a direction practically orthogonal to a rubbing axis and the discotic liquid crystal compound of the second optically anisotropic layer is aligned by a liquid crystal alignment layer so as to have the optic axis in a direction practically parallel to a rubbing axis. Also, the circularly polarizing plate is provided with the optical retardation plate and a polarizing film. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a retardation plate effective as a λ / 4 plate used for a reflection type liquid crystal display device, a pickup for writing an optical disc, or an antireflection film, and a circular polarizing plate using the same. And the manufacturing methods thereof. In particular, the present invention relates to a retardation plate having an elongated transparent support and an optically anisotropic layer having a multilayer structure of rod-shaped liquid crystals formed by coating on the support, and a polarizing plate and a roll-to-roll method using the retardation plate. TECHNICAL FIELD The present invention relates to a circularly polarizing plate that can be laminated and manufactured, and a manufacturing method thereof.

[0002]

2. Description of the Related Art The .lambda. / 4 plate has numerous uses and is already in actual use. However, even if it is called a λ / 4 plate, most of them achieve λ / 4 at a certain specific wavelength. JP-A-10-68816 and JP-A-10-90521 disclose a retardation plate obtained by laminating two polymer films having optical anisotropy. The retardation plate described in JP-A-10-68816 is a quarter-wave plate in which the phase difference of birefringent light is ¼ wavelength and a half-wave plate in which the phase difference of birefringent light is ½ wavelength. The wave plate and the wave plate are attached in a state where their optical axes intersect. The retardation plate described in JP-A-10-90521 has a retardation value of 160 to 320 n.
At least two retardation plates of m are laminated so that their slow axes are at angles that are neither parallel nor orthogonal to each other. The retardation film described in any of the publications is specifically composed of a laminate of two polymer films. Both publications explain that this makes it possible to achieve λ / 4 in a wide wavelength range. However, in the production of the retardation film described in JP-A-10-68816 and JP-A-10-90521, in order to adjust the optical orientation (optical axis or slow axis) of two polymer films, two It is necessary to cut various kinds of polymer films at a predetermined angle and bond the obtained chips. If the phase difference plate is manufactured by laminating chips, the processing is complicated, quality deterioration easily occurs due to axial misalignment, yield decreases, cost increases, and deterioration due to contamination easily occurs. Further, it is difficult to strictly control the retardation value of the polymer film. On the other hand, a method for providing a broadband λ / 4 plate more simply by providing at least two optically anisotropic layers containing a liquid crystal compound is disclosed in Japanese Patent Laid-Open No. 2001-4837.
No. 2001-21720, No. 2000-
No. 206331 is disclosed. Particularly, the method of Japanese Patent Laid-Open No. 2001-4837 in which the same liquid crystal molecules can be used is attractive from the viewpoint of manufacturing cost.

[0003]

By the way, when laminating optically anisotropic layers containing a liquid crystalline compound to produce a retardation plate, it is important to control the orientation of the liquid crystalline compound.
For example, the rod-shaped liquid crystalline compound can form an optically anisotropic layer by horizontally aligning it with respect to the substrate. When a layer containing a rod-shaped liquid crystalline compound is formed on a rubbing-treated liquid crystal alignment film, the rod-shaped liquid crystalline compound is normally horizontally aligned with its long axis aligned with the rubbing direction. However, as a result of diligent study by the present inventor
When a normal liquid crystal alignment film in which liquid crystal molecules are aligned in a direction coinciding with the rubbing axis is used when forming the liquid crystal molecular layer disclosed in JP-A-01-4837, the accuracy of liquid crystal alignment is reduced. Turned out to be. Further, it was found that many optical defects occur depending on the kind of rod-shaped liquid crystal compound or the composition of the liquid crystal composition.

The present invention has been made in view of the above problems, and it functions as a retardation plate in a wide band (visible light wavelength range), can be thinned, and can be manufactured easily and stably. An object is to provide a retardation plate. Another object of the present invention is to provide a circularly polarizing plate that functions as a circularly polarizing plate in a wide band (visible light wavelength range), can be thinned, and can be manufactured easily and stably. Further, the present invention provides a retardation plate and a circularly polarizing plate which function well in a wide band (visible light wavelength region) and can be thinned, by stably controlling the alignment of liquid crystal compound molecules. An object is to provide a method for manufacturing a retardation plate and a circularly polarizing plate that can be easily and stably manufactured. Another object of the present invention is to provide a novel liquid crystal alignment control technology for discotic liquid crystals.

[0005]

Means for solving the problems Means for solving the above problems are as follows. (1) A long transparent support, and a vertically aligned discotic liquid crystal compound, and a measurement wavelength of 550.
the first optically anisotropic layer having a phase difference of substantially π in nm and a vertically aligned discotic liquid crystal compound, and having a phase difference of substantially π / 2 at a measurement wavelength of 550 nm.
And a first liquid crystal alignment film having a rubbing axis for vertically aligning the discotic liquid crystal compound of the first optical anisotropic layer and determining the azimuth angle of the optical axis. And a second liquid crystal alignment film having a rubbing axis that vertically aligns the discotic liquid crystalline compound of the second optically anisotropic layer and determines the azimuth angle of the optical axis, and the first optical An angle between the in-plane slow axis of the anisotropic layer and the longitudinal direction of the transparent support is substantially 75 °, and the in-plane slow axis of the second optically anisotropic layer and the transparent The angle with the longitudinal direction of the support is substantially 15 °, the in-plane slow axis of the second optically anisotropic layer and the in-plane slow axis of the first optically anisotropic layer. And the discotic liquid crystal compound of the first optically anisotropic layer is an optical axis with respect to the rubbing axis of the first liquid crystal alignment film. Are substantially perpendicular to each other, and the discotic liquid crystal compound of the second optically anisotropic layer has an optical axis substantially parallel to the rubbing axis of the second liquid crystal alignment film. A retardation plate characterized by being vertically aligned with. (2) A long transparent support, and a vertically aligned discotic liquid crystal compound, and a measurement wavelength of 550.
the first optically anisotropic layer having a phase difference of substantially π in nm and a vertically aligned discotic liquid crystal compound, and having a phase difference of substantially π / 2 at a measurement wavelength of 550 nm.
And a first liquid crystal alignment film having a rubbing axis for vertically aligning the discotic liquid crystal compound of the first optical anisotropic layer and determining the azimuth angle of the optical axis. And a second liquid crystal alignment film having a rubbing axis that vertically aligns the discotic liquid crystalline compound of the second optically anisotropic layer and determines the azimuth angle of the optical axis, and the first optical An angle between the in-plane slow axis of the anisotropic layer and the longitudinal direction of the transparent support is substantially 75 °, and the in-plane slow axis of the second optically anisotropic layer and the transparent The angle with the longitudinal direction of the support is substantially 15 °, the in-plane slow axis of the second optically anisotropic layer and the in-plane slow axis of the first optically anisotropic layer. And the angle between the rubbing axis of the first liquid crystal alignment film and the longitudinal direction of the transparent support is substantially -15 °. Ri, and a phase difference plate, wherein the angle between the longitudinal direction of the transparent support and the rubbing axis of the second liquid crystal alignment layer is substantially 15 °.

(3) The first liquid crystal alignment film contains at least one polyacrylic acid copolymer or polymethacrylic acid copolymer containing a repeating unit represented by the following general formula (I). The retardation plate according to (1) or (2).

[0007]

[Chemical 1]

In the formula, R ¹ represents a hydrogen atom or a methyl group, R ² represents an atom or a group selected from the group consisting of a hydrogen atom, a halogen atom and an alkyl group having 1 to 6 carbon atoms, and M ¹ Represents an alkali metal atom, L ¹ represents -O
Represents a divalent linking group selected from the group consisting of —, —CO—, —NH—, an alkylene group and a combination thereof;
² , L ³ and L ⁴ are each independently an ethynylene group, a single bond, —CO—, —O—CO—, —CO—O—, —alkylene group —O—, —CO—NH—, —O—. CO-O-,
Represents a divalent linking group selected from the group consisting of —NHSO ₂ — and combinations thereof, wherein Ar ¹ , Ar ² , Ar ³ and Ar ⁴ are each independently an aromatic ring which may have a substituent. Or an aromatic heterocycle, m and n each independently represent 0 or 1, x and y represent mol% of each repeating unit, x is 10 to 95 mol%, and y is 5 to 90%. Represents mol%.

(4) The second liquid crystal alignment film contains at least one polyacrylic acid copolymer or polymethacrylic acid copolymer containing a repeating unit represented by the following general formula (II). The retardation plate according to any one of (1) to (3).

[0010]

[Chemical 2]

In the formula, R ¹ represents a hydrogen atom or a methyl group, R ² represents a hydrogen atom, a halogen atom and an atom or group selected from the group consisting of alkyl groups having 1 to 6 carbon atoms, and M ² Represents an ammonium group which may have a substituent, L ¹ represents a divalent linking group selected from the group consisting of —O—, —CO—, —NH—, an alkylene group and a combination thereof; L ² , L ³ and L ⁴ are each independently an ethynylene group, a single bond, —CO—, —O—CO.
-, -CO-O-, -alkylene group -O-, -CO-N
H -, - O-CO- O -, - NHSO 2 - and represents a divalent linking group selected from the group consisting of,
Ar ¹ , Ar ² , Ar ³ and Ar ⁴ each independently represent an aromatic ring or an aromatic heterocycle which may have a substituent, and m and n each independently represent 0 or 1. , X and y represent mol% of each repeating unit, x represents 10 to 95 mol% and y represents 5 to 90 mol%.

(5) Each of the first optically anisotropic layer and the second optically anisotropic layer contains at least one compound represented by the following general formula (III), Any of (1) to (4), wherein the polar layer orientation angle of the discotic liquid crystalline compound in each of the anisotropic layer and the second optically anisotropic layer is substantially 80 ° or more. The retardation plate according to Crab. Formula ^{(III) (Hb-L 5} -) during _n B ¹ expression, Hb is an aliphatic group having 6 to 40 carbon atoms, a fluorine-substituted aliphatic group or the number of carbon atoms of carbon atoms from 4 to 40 Represents an aliphatic-substituted oligosiloxane group of 4 to 40, L
⁵ -O -, - S -, - CO -, - NR 5 -, - SO
_2- , an alkylene group, an alkenylene group, an arylene group and a divalent linking group selected from the group consisting of them, R ⁵ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and n represents It represents an integer of 2 to 12, and B ¹ represents an n-valent group containing at least three cyclic structures.

(6) At least one of the discotic liquid crystalline compounds contained in the first optically anisotropic layer is represented by the following general formula (IV) (1) to (5) ) The retardation plate according to any of 1. In the general formula (IV) D ¹ (-LP ¹ ) _n , D ¹ represents a disc-shaped core portion, L represents a divalent linking group, P ¹ represents a polymerizable group, and n represents 4 Represents an integer from 1 to 12.

(7) A first liquid crystal alignment film having a rubbing axis having an angle of substantially −15 ° with the longitudinal direction of the transparent support is formed above the elongated transparent support. And a step of forming a layer containing a discotic liquid crystalline compound on the first liquid crystal alignment film,
The discotic liquid crystal compound is vertically aligned in a direction in which the optical axis is substantially perpendicular to the rubbing axis, and a measurement wavelength 55
A first optically anisotropic layer forming step of forming a first optically anisotropic layer having a phase difference of substantially π at 0 nm, and a longitudinal direction of the transparent substrate above the transparent substrate. A second liquid crystal alignment film forming step of forming a second liquid crystal alignment film having a rubbing axis whose angle is substantially 15 °, and containing a discotic liquid crystalline compound on the second liquid crystal alignment film. A layer is formed and the discotic liquid crystalline compound is orientated at an azimuth angle at which the optical axis is substantially parallel to the rubbing axis of the second liquid crystal orientation film, and the measurement wavelength is 550 nm.
And a second optically anisotropic layer-forming step of forming a second optically anisotropic layer having a retardation of substantially π / 2. (8) The first liquid crystal alignment film forming step and the first
The method for producing a retardation plate according to (7), wherein after the step of forming the optically anisotropic layer, the step of forming the second liquid crystal alignment film and the step of forming the second optically anisotropic layer are performed. (9) The second liquid crystal alignment film forming step and the second
The method for producing a retardation plate according to (7), wherein after the step of forming the optically anisotropic layer, the step of forming the first liquid crystal alignment film and the step of forming the first optically anisotropic layer are performed.

(10) Substantially with an arbitrary in-plane axis a1
A first liquid crystal alignment film forming step of forming a first liquid crystal alignment film having a rubbing axis in a direction forming 15 °, and forming a layer containing a discotic liquid crystal compound on the first liquid crystal alignment film. At the same time, the discotic liquid crystalline compound is oriented such that its optical axis is substantially orthogonal to the rubbing axis of the first liquid crystal orientation film and is substantially 75 ° to the in-plane axis a1. The angle between the first optically anisotropic layer forming step of forming the first optically anisotropic layer having a phase difference of substantially π at a measurement wavelength of 550 nm and the arbitrary in-plane axis a2 is substantially Forming a second liquid crystal alignment film having a rubbing axis of 15 °; forming a layer containing a discotic liquid crystal compound on the second liquid crystal alignment film; Its optical axis is relative to the rubbing axis of the second liquid crystal alignment film. Qualitatively vertically aligned in a direction parallel to the phase difference at a measurement wavelength 550nm is substantially π
The second optically anisotropic layer forming step of forming a second optically anisotropic layer of / 2 and the first optically anisotropic layer and the second optically anisotropic layer are respectively performed. In-plane axes a1 and a
And 2 are substantially parallel to each other and the latitudinal axis of the first optically anisotropic layer and the latitudinal axis of the second optically anisotropic layer are substantially 60 °. A method of manufacturing a retardation plate including. In the manufacturing method described in (10), the first and second optically anisotropic layers may be laminated after being peeled from the respective liquid crystal alignment films, or may be laminated without peeling. Good. In addition, the first optically anisotropic layer forming step or the second
The step of forming the optically anisotropic layer may also serve as the laminating step.

(11) A first optical anisotropy containing a long transparent support and a vertically aligned discotic liquid crystal compound above the transparent support, and having a retardation of substantially π at a measurement wavelength of 550 nm. A layer, a second optically anisotropic layer containing a vertically aligned discotic liquid crystal compound and having a retardation of substantially π / 2 at a measurement wavelength of 550 nm;
A first liquid crystal alignment film having a rubbing axis that vertically aligns the discotic liquid crystalline compound of the optically anisotropic layer and determines the azimuth angle of the optical axis, and the discotic liquid crystal of the second optically anisotropic layer. And a second liquid crystal alignment film having a rubbing axis for determining an azimuth angle of an optical axis and a polarizing film below the transparent support, the polarizing film comprising: The polarization axis is substantially orthogonal to the longitudinal direction of the transparent support, and the angle between the in-plane slow axis of the first optically anisotropic layer and the longitudinal direction of the transparent support is substantially 75 °. And the angle between the slow axis in the plane of the second optically anisotropic layer and the longitudinal direction of the transparent support is substantially 15 °, and the plane of the second optically anisotropic layer. The angle between the in-plane slow axis and the in-plane slow axis of the first optically anisotropic layer is substantially 60 °. The discotic liquid crystal compound of the anisotropic layer is vertically aligned in a direction in which the optical axis is substantially orthogonal to the rubbing axis of the first liquid crystal alignment film, and the disc of the second optically anisotropic layer. A circularly polarizing plate, wherein the liquid crystal compound is vertically aligned in a direction in which the optical axis is substantially parallel to the rubbing axis of the second liquid crystal alignment film. (12) A long transparent support, and a vertically aligned discotic liquid crystal compound, and a measurement wavelength of 55.
It contains a first optically anisotropic layer having a phase difference of substantially π at 0 nm and a vertically aligned discotic liquid crystal compound, and has a phase difference of substantially π / at a measurement wavelength of 550 nm.
No. 2 second optical anisotropic layer and the first liquid crystal alignment having a rubbing axis for vertically aligning the discotic liquid crystalline compound of the first optical anisotropic layer and determining the azimuth angle of the optical axis. A film, a second liquid crystal alignment film having a rubbing axis for vertically aligning the discotic liquid crystalline compound of the second optically anisotropic layer and determining an azimuth angle of an optical axis, and below the transparent support. A circularly polarizing plate including a polarizing film, wherein the polarizing axis of the polarizing film is substantially orthogonal to the longitudinal direction of the transparent support, and the in-plane slow axis of the first optically anisotropic layer is And the longitudinal direction of the transparent support is substantially 75 °, and the angle between the slow axis in the plane of the second optically anisotropic layer and the longitudinal direction of the transparent support is substantially. At 15 ° and the second
The angle between the in-plane slow axis of the optically anisotropic layer and the in-plane slow axis of the first optically anisotropic layer is substantially 60 °, and The angle between the rubbing axis and the longitudinal direction of the transparent support is substantially −15 °, and the angle between the rubbing axis of the second liquid crystal alignment film and the longitudinal direction of the transparent support is substantially 15 °. A circularly polarizing plate characterized by being at a degree. (13) A first optically anisotropic layer containing a vertically aligned discotic liquid crystalline compound and having a retardation of substantially π at a measurement wavelength of 550 nm, and a vertically aligned discotic liquid crystalline compound containing a measurement wavelength. The second optically anisotropic layer having a retardation of substantially π / 2 at 550 nm and the discotic liquid crystal compound of the first optically anisotropic layer are vertically aligned and the azimuth angle of the optical axis is determined. A first liquid crystal alignment film having a rubbing axis and a second liquid crystal alignment having a rubbing axis that determines the azimuth angle of the optical axis while vertically aligning the discotic liquid crystal compound of the second optically anisotropic layer. A circularly polarizing plate having a film and a polarizing film, wherein an angle between an in-plane slow axis of the first optically anisotropic layer and an absorption axis of the polarizing film is substantially 75 °, In-plane slow axis of the second optically anisotropic layer and the polarizing film The angle with the absorption axis is substantially 15 °, and the angle between the in-plane slow axis of the second optically anisotropic layer and the in-plane slow axis of the first optically anisotropic layer. Is substantially 60 °, and the discotic liquid crystal compound of the first optically anisotropic layer is vertically aligned in a direction in which the optical axis is substantially perpendicular to the rubbing axis of the first liquid crystal alignment film. And the second
The discotic liquid crystal compound of the optically anisotropic layer is vertically aligned in a direction in which the optical axis is substantially parallel to the rubbing axis of the second liquid crystal alignment film. (14) A first optically anisotropic layer containing a vertically aligned discotic liquid crystalline compound and having a phase difference of substantially π at a measurement wavelength of 550 nm, and a vertically aligned discotic liquid crystalline compound and a measurement wavelength. The second optically anisotropic layer having a retardation of substantially π / 2 at 550 nm and the discotic liquid crystal compound of the first optically anisotropic layer are vertically aligned and the azimuth angle of the optical axis is determined. First liquid crystal alignment film having a rubbing axis and a second liquid crystal alignment film having a rubbing axis for vertically aligning the discotic liquid crystalline compound of the second optically anisotropic layer and determining the azimuth angle thereof. When,
A circularly polarizing plate including a polarizing film, wherein an angle between an in-plane slow axis of the first optically anisotropic layer and an absorption axis of the polarizing film is substantially 75 °, The angle between the in-plane slow axis of the optically anisotropic layer and the absorption axis of the polarizing film is substantially 15 °, and the in-plane slow axis of the second optically anisotropic layer is The angle with the in-plane slow axis of the first optically anisotropic layer is substantially 60 °, and the angle between the rubbing axis of the first liquid crystal alignment film and the absorption axis of the polarizing film is substantially. At -15 °,
A circularly polarizing plate characterized in that the angle between the rubbing axis of the second liquid crystal alignment film and the absorption axis of the polarizing film is substantially 15 °.

(15) The first liquid crystal alignment film contains at least one polyacrylic acid copolymer or polymethacrylic acid copolymer containing a repeating unit represented by the general formula (I). The circularly polarizing plate according to any one of (11) to (14). (16) The second liquid crystal alignment film is characterized by containing at least one polyacrylic acid copolymer or polymethacrylic acid copolymer containing a repeating unit represented by the general formula (II) ( The circularly polarizing plate according to any one of 11) to (15). (17) The first optically anisotropic layer and the second optically anisotropic layer each contain at least one compound represented by the general formula (III), (11) to (16), wherein the orientation angle in the polar angle direction of the discotic liquid crystalline compound in each of the layer and the second optically anisotropic layer is substantially 80 ° or more. Circular polarizing plate. (18) Any of (11) to (17), wherein at least one kind of discotic liquid crystalline compound contained in the first optically anisotropic layer is represented by the following general formula (IV). A circularly polarizing plate described in Crab.

(19) Above the long transparent support,
The angle with the longitudinal direction of the transparent support is substantially -15 °.
A first liquid crystal alignment film forming step of forming a first liquid crystal alignment film having a rubbing axis, and forming a layer containing a discotic liquid crystalline compound on the first liquid crystal alignment film, Forming a first optically anisotropic layer having a phase difference of substantially π at a measurement wavelength of 550 nm by orienting the liquid crystalline compound in a direction in which the optical axis is substantially orthogonal to the rubbing axis. 1 is an optically anisotropic layer forming step,
A second rubbing shaft having an angle of substantially 15 ° with the longitudinal direction of the transparent support above the transparent support.
A second liquid crystal alignment film forming step of forming the liquid crystal alignment film of
A layer containing a discotic liquid crystalline compound is formed on the second liquid crystal alignment film, and the discotic liquid crystalline compound has an optical axis substantially with respect to the rubbing axis of the second liquid crystal alignment film. Aligned vertically with parallel azimuth angle and measured wavelength 550
a second optically anisotropic layer-forming step of forming a second optically anisotropic layer having a phase difference of substantially π / 2 in nm, and a length of the transparent substrate below the transparent substrate. Forming a polarizing film having a polarization axis in a direction substantially perpendicular to the longitudinal direction of the transparent support by making the direction substantially coincident with the absorption axis. (20) After the first liquid crystal alignment film forming step and the first optical anisotropic layer forming step, the second liquid crystal aligning film forming step and the second optical anisotropic layer forming step are performed. The method for producing a circularly polarizing plate according to (19). (21) After the second liquid crystal alignment film formation step and the second optical anisotropic layer formation step, the first liquid crystal alignment film formation step and the first optical anisotropic layer formation step are performed. The method for producing a circularly polarizing plate according to (19).

(22) Substantially with any in-plane axis a1
Forming a first liquid crystal alignment film having a rubbing axis in a direction forming 15 °; forming a layer containing a discotic liquid crystalline compound on the first liquid crystal alignment film; The compound is orientated so that its optical axis is substantially perpendicular to the rubbing axis of the first liquid crystal alignment film and is substantially perpendicular to the in-plane axis a1 at a measurement wavelength of 550.
The angle between the first optically anisotropic layer forming step of forming the first optically anisotropic layer having a retardation in nm of substantially π and the arbitrary in-plane axis a2 is substantially 15 °. Forming a second liquid crystal alignment film having a certain rubbing axis;
A layer containing a discotic liquid crystalline compound is formed on the liquid crystal alignment film, and the discotic liquid crystal compound is oriented in a direction in which its optical axis is substantially parallel to the rubbing axis of the second liquid crystal alignment film. Vertically aligning to form a second optically anisotropic layer having a phase difference of substantially π / 2 at a measurement wavelength of 550 nm, the first optically anisotropic layer and the second optically anisotropic layer.
The in-plane axes a1 and a2 thereof are substantially parallel to each other, and the slow axis of the first optically anisotropic layer and the slow axis of the second optically anisotropic layer. Laminating with an angle of substantially 60 ° with the in-plane axes a1 and a
2. A method of manufacturing a circularly polarizing plate, which comprises the step of forming a polarizing film having a polarization axis in a direction substantially perpendicular to 2.

In the present specification, "substantially 15 °",
“Substantially −15 °”, “substantially 75 °”, “substantially 60 °”, “substantially parallel” or “substantially orthogonal” means a range of a strict angle of less than ± 5 °. Means within. The error from the strict angle is preferably less than 4 °, more preferably less than 3 °. In the present specification, "slow axis" means the direction in which the refractive index is maximized, "optical axis" means the direction in which incident light does not exhibit birefringence, and "rubbing axis" means the direction of rubbing treatment. Means direction. Furthermore, in the present specification, “above the transparent support” and “below the transparent support” merely indicate directions with the transparent support as the center, and the retardation plate and the circularly polarizing plate of the present invention are It should not be construed as limiting the manner in which it is used.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
The retardation plate of the present invention contains a transparent support and a vertically aligned discotic liquid crystal compound above the transparent support, and has a measurement wavelength of 5
It includes a first optically anisotropic layer having a retardation of substantially π at 50 nm and a vertically aligned discotic liquid crystal compound, and has a retardation of substantially π at a measurement wavelength of 550 nm.
The second optically anisotropic layer having a thickness of / 2 is laminated. Further, the circularly polarizing plate of the present invention has a structure in which a polarizing film is provided below the transparent support of the retardation plate of the present invention. In the retardation plate and the circularly polarizing plate of the present invention, the stacking order of the first optically anisotropic layer and the second optically anisotropic layer is not particularly limited, and which is closer to the transparent support. It may be.

Each of the first and second optically anisotropic layers has only to achieve a phase difference of π or π / 2 at a specific wavelength. However, it is preferable that the phase difference π or π / 2 is achieved at 550 nm which is a wavelength approximately in the middle of the visible region. Specific wavelength (λ)
To achieve the phase difference π at
The retardation value of the optically anisotropic layer measured in 1. may be adjusted to λ / 2. In order to achieve the phase difference π / 2 at the specific wavelength (λ), the retardation value of the optically anisotropic layer measured at the specific wavelength (λ) may be adjusted to λ / 4. That is, the first optically anisotropic layer has a retardation value of 240 to 240 measured at a wavelength of 550 nm.
290 nm is preferable, and 250 to 280 nm
Is more preferable. The second optically anisotropic layer has a retardation value of 1 measured at a wavelength of 550 nm.
It is preferably 10 to 145 nm, and 120 to 14
More preferably, it is 0 nm.

The retardation value means an in-plane retardation value with respect to light incident from the direction normal to the optically anisotropic layer. Specifically, it is a value defined by the following formula. Retardation value (Re) = (nx−ny) × d, where nx and ny are main in-plane refractive indices of the optically anisotropic layer or the birefringent film, and d is the optically anisotropic layer or It is the thickness (nm) of the birefringence film. Japanese Patent Laid-Open No. 10-68816 describes a Poincare sphere for achieving circularly polarized light.

FIG. 1 is a schematic view showing the basic structure of the retardation plate of the present invention. As shown in FIG. 1, in addition to the elongated transparent support (S) and the first optically anisotropic layer (A), the basic retardation plate has a second optically anisotropic layer ( B). The retardation of the first optically anisotropic layer (A) is substantially π.
And the retardation of the second optically anisotropic layer (B) is substantially π / 2. The angle (α) between the longitudinal direction (s) of the transparent support (S) and the in-plane slow axis (a) of the first optically anisotropic layer (A) is 75 °. The rubbing axis (ra) and the slow axis (a) of the liquid crystal alignment film of the first optically anisotropic layer (A) are orthogonal to each other. The angle (β) between the in-plane slow axis (b) of the second optically anisotropic layer (B) and the longitudinal direction (s) of the transparent support (S) is 15 °. The rubbing axis (rb) and the slow axis (b) of the liquid crystal alignment film of the second optically anisotropic layer (B) are aligned with each other. The angle (γ between the in-plane slow axis (b) of the second optically anisotropic layer (B) and the in-plane slow axis (a) of the first optically anisotropic layer (A). ) Is 60 °. The first optically anisotropic layer (A) and the second optically anisotropic layer (B) shown in FIG. 1 each include discotic liquid crystal compound molecules (c1 and c2). The discotic liquid crystal compound molecules (c1 and c2) are vertically aligned. The lines of intersection of the disk surfaces of the disk-shaped liquid crystalline molecules (c1 and c2) and the horizontal planes of the optically anisotropic layer (A) and the optically anisotropic layer (B) are the slow axes (a) and (b). Equivalent to.

FIG. 2 is a schematic view showing a typical constitution of the circularly polarizing plate of the present invention. The circularly polarizing plate shown in FIG. 2 is further polarized in addition to the transparent support (S), the first optically anisotropic layer (A) and the second optically anisotropic layer (B) shown in FIG. It has a membrane (P). As in FIG. 1, the angle (α) between the longitudinal direction (s) of the transparent support (S) and the in-plane slow axis (a) of the first optically anisotropic layer (A) was 75 °. Yes, the in-plane slow axis (f) of the second optically anisotropic layer (B) and the transparent support (S)
The angle (β) with respect to the longitudinal direction (s) is 15 °, and the in-plane slow axis (b) of the second optically anisotropic layer (B) and the first optically anisotropic layer The angle (γ) with the in-plane slow axis (a) of (A) is 60 °. Further, the polarization axis (p) of the polarizing film (P) and the longitudinal direction (s) of the transparent support (S) are orthogonal to each other. The first optically anisotropic layer (A) and the second optically anisotropic layer (B) shown in FIG. 2 also each include discotic liquid crystal compound molecules (c1 and c2). The discotic liquid crystal compound molecules (c1 and c2) are orthogonally aligned. The lines of intersection of the disk surfaces of the disk-shaped liquid crystalline molecules (c1 and c2) and the horizontal planes of the optically anisotropic layer (A) and the optically anisotropic layer (B) are aligned with their slow axes (a) and (b). Equivalent to.

Materials used for manufacturing the retardation film of the present invention and manufacturing examples thereof will be described in detail below.
In the following description, for convenience, a method of manufacturing a retardation plate having a structure in which first and second optically anisotropic layers are sequentially laminated on a transparent support will be described. The order of laminating the optically anisotropic layers may be reversed.

In the retardation plate of the present invention, first, the discotic liquid crystalline compound contained in the first optically anisotropic layer is vertically aligned above the transparent support to determine the azimuth angle of the optical axis. First
Forming a liquid crystal alignment film. In the present invention, the discotic liquid crystal compound in the first optically anisotropic layer is vertically aligned by using the rubbing-treated first liquid crystal alignment film, and The discotic liquid crystalline compound is oriented in a direction in which the axis is substantially perpendicular to the rubbing axis. That is, in the discotic liquid crystalline compound, in the first optically anisotropic layer, a direction in which the disc surface is perpendicular to the horizontal plane of the optically anisotropic layer and is substantially orthogonal to the rubbing axis. They are arranged in a stack with the disk side facing. When the optical axis of the discotic liquid crystalline compound molecules is oriented at an angle larger than 45 ° with respect to the long axis direction of the transparent support, the optical axes of the discotic liquid crystalline molecules should be aligned in the direction orthogonal to the rubbing direction. A stable alignment can be achieved by using a different liquid crystal alignment film (hereinafter, referred to as an orthogonal liquid crystal alignment film).

For example, a surface of a long transparent support is coated with a solution of a polymer which is a material for an orthogonal liquid crystal alignment film described later, dried to form a film, and then subjected to rubbing treatment to obtain an orthogonal liquid crystal. An alignment film can be formed. The rubbing treatment can be carried out by rubbing the surface of the film with paper or cloth in a certain direction several times. In the present invention, the rubbing treatment can be performed in a direction in which the angle with the longitudinal direction of the transparent support is substantially -15 °. That is, the angle between the rubbing axis and the longitudinal direction of the transparent support is substantially -1.
The rubbing treatment can be performed so that the angle becomes 5 °. On the formed orthogonal liquid crystal alignment film, a coating liquid containing a discotic liquid crystal compound is applied to orient the discotic liquid crystal compound, and the liquid crystal molecules are aligned with the rubbing axis of the orthogonal liquid crystal alignment film. And is oriented in a direction substantially forming 90 °. That is,
The discotic liquid crystalline compounds are stacked and oriented with their disc faces facing in the direction of 75 ° with respect to the longitudinal direction of the transparent support to form a first optically anisotropic layer having a phase difference of π. be able to.

The orthogonal liquid crystal alignment film has a thickness of 0.01 to
The thickness is preferably 5 μm, more preferably 0.05 to 1 μm. In addition, after forming a first liquid crystal alignment film (orthogonal liquid crystal alignment film) on the temporary support and further orienting the discotic liquid crystal compound of the first optically anisotropic layer, the first liquid crystal layer is formed. It may be transferred onto a transparent support. The liquid crystal compound fixed in the alignment state can maintain the alignment state without the liquid crystal alignment film.

Next, a second liquid crystal alignment film is formed, and a second optically anisotropic liquid crystal layer is formed on the second liquid crystal alignment film. In the second liquid crystal alignment film, the discotic liquid crystal compound in the second optically anisotropic layer is aligned orthogonally, and the optical axis of the second optical anisotropic layer is substantially aligned with the rubbing axis. The discotic liquid crystalline compound is oriented in the direction parallel to the. That is, the discotic liquid crystalline compound is the first
In the optically anisotropic layer, the disk surfaces are arranged so that the disk surfaces are perpendicular to the horizontal plane of the optically anisotropic layer and the disk surfaces are oriented in a direction substantially parallel to the rubbing axis. .

As the second liquid crystal alignment film, a liquid crystal alignment film formed by rubbing a polymer film is particularly preferable. The rubbing treatment is carried out by rubbing the surface of the polymer layer with paper or cloth in a certain direction several times. For example, after coating a polymer solution on the surface of the first optically anisotropic layer and drying it to form a film,
A second liquid crystal alignment film can be formed by performing rubbing treatment. In the present invention, the second liquid crystal alignment film can be formed by performing a rubbing treatment in a direction in which the angle with the longitudinal direction of the transparent support is substantially 15 °. That is, the rubbing treatment is performed so that the angle between the rubbing axis and the longitudinal direction of the transparent support is substantially 15 °,
A second liquid crystal alignment film can be formed. When a coating liquid containing a discotic liquid crystalline compound is applied onto the formed second liquid crystal orientation film orthogonal liquid crystal orientation film to orient the discotic liquid crystalline compound, the liquid crystal molecules are dispersed in the liquid crystal orientation film. Is oriented in a direction substantially parallel to the rubbing axis of. That is,
The discotic liquid crystalline compounds are stacked and oriented with their disc faces oriented in a direction of 15 ° with respect to the longitudinal direction of the transparent support to form a second optically anisotropic layer having a phase difference of π / 2. Can be formed.

The thickness of the second liquid crystal alignment film is 0.01
The thickness is preferably -5 μm, more preferably 0.05-1 μm. In addition, after forming a second liquid crystal alignment film on the temporary support and aligning the liquid crystal compound of the second optically anisotropic layer to form the second optically anisotropic layer, the second liquid crystal alignment film is formed.
The optically anisotropic layer may be transferred to a transparent support (or on the first optically anisotropic layer). The liquid crystal compound fixed in the alignment state can maintain the alignment state without the liquid crystal alignment film. In order to laminate the first optically anisotropic layer and the second optically anisotropic layer, in the longitudinal direction of the support (or the temporary support) when the first optically anisotropic layer is formed. When the parallel in-plane axis is a1 and the in-plane axis parallel to the longitudinal direction of the temporary support (or the transparent support) when the second optically anisotropic layer is formed is a2, each plane The inner axes a1 and a2 are substantially parallel, and the angle between the slow axis of the first optically anisotropic layer and the slow axis of the second optically anisotropic layer is substantially 60 °, The first optically anisotropic layer and the second optically anisotropic layer are laminated.

The first liquid crystal alignment film (orthogonal liquid crystal alignment film)
The above is described in Japanese Patent Application Nos. 2000-91888 and 2000-214582.
Among them, more preferable is an orthogonal alignment film containing a repeating unit represented by the following general formula (I). In addition, the second liquid crystal alignment film is preferably an alignment film containing a repeating unit represented by the following general formula (II).

[0034]

[Chemical 3]

[0035]

[Chemical 4]

In the above formulas (I) and (II), R ¹ represents a hydrogen atom or a methyl group, and R ² is selected from the group consisting of a hydrogen atom, a halogen atom and an alkyl group having 1 to 6 carbon atoms. Represents an atom or a group, L ¹ is —O—, —C
O -, - NH-, a divalent linking group selected from the group consisting of an alkylene group and combinations thereof, to L ^2, L ³ and L ⁴ are each independently, an ethynylene group, a single bond, -
CO-, -O-CO-, -CO-O-, -alkylene group -O-, -CO-NH-, -O-CO-O-, -NHS
Represents a divalent linking group selected from the group consisting of O ₂ − and combinations thereof, and Ar ¹ , Ar ² , Ar ³ and Ar ⁴ each independently represent an aromatic ring which may have a substituent or Represents an aromatic heterocycle, m and n each independently represent 0 or 1, x and y represent mol% of each repeating unit, x is 10 to 95 mol% and y is 5
Represents ~ 90 mol%.

In the general formula (I), M ¹ represents an alkali metal atom, and in the general formula (II), M ² represents an ammonium group which may have a substituent. The alkali metal atom represented by M ¹ is preferably sodium, potassium, lithium or cesium. The ammonium group which may have a substituent represented by M ² is NH
₄ , NH ₃ (CH ₃ ), NH ₃ (C ₂ H) ₅ , NH ₃ (nC _{3
H 7), NH 3 (n} -C 4 H 9), NH 2 (CH 3) 2, NH 2
_{(C 2 H 2 OH) 2} , NH 2 (C 2 H 5) 2, NH 2 (n-C 3
_{H 7) 2, NH 2 (} i-C 3 H 7) 2, NH 2 CH 3 (n-C 4
_{H 9), NH 2 (CH} 3) 2, NH 2 (n-C 4 H 9) 2, NH
_{(CH 3) 3, NH (} C 2 H 5) 3, NHCH 3 (n-C
_{4 H 9), NHC 2 H} 5 (i-C 3 H 7) 2, NH (CH 2 CH
It is preferably OHCH ₃ ) ₃ or N (CH ₃ ) ₄ . Here, in the general formulas (I) and (II), depending on whether the counter cation is M ¹ or M ² , the light of the discotic liquid crystal compound molecule (discotic liquid crystal compound molecule) in the rubbing direction is detected. The azimuth direction of the axis is controlled.

R ¹ represents a hydrogen atom or a methyl group (when R ¹ is H, it represents a polyacrylic acid copolymer, and when R ¹ is a methyl group, it represents a polymethacrylic acid copolymer). R ² represents an atom or a group selected from the group consisting of a hydrogen atom, a halogen atom, and an alkyl group having 1 to 6 carbon atoms. The alkyl group having 1 to 6 carbon atoms is preferably a methyl group or an ethyl group,
A methyl group is particularly preferable.

L ¹ is -O-, -CO-, -NH-,-.
An alkylene group-represents a divalent linking group selected from the group consisting of these and combinations thereof. L ¹ is -CO-O
-, -CO-NH-, -CO-O-alkylene group-,-
A CO-O-alkylene group -O- or a -CO-O-alkylene group -CO-O- is preferable, and -CO
It is particularly preferably -O- or -CO-NH-. L ² , L ³ and L ⁴ are each independently -ethynylene group-(-C≡C-), single bond, -CO-, -O-C.
O-, -CO-O-, -alkylene group -O-, -CO-
NH -, - O-CO- O -, - NHSO 2 - and -N
It represents a bond or a divalent linking group selected from the group consisting of HCO-O-. It is preferable that at least one of L ² , L ³ and L ⁴ independently represents a single bond or —ethynylene group — (— C≡C—). The alkylene group may have a branched or cyclic structure. The alkylene group has preferably 1 to 30 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 12 carbon atoms.

Ar ¹ , Ar ² , Ar ³ and Ar ⁴ each independently represent an aromatic ring or an aromatic heterocycle which may have a substituent. The aromatic ring or aromatic heterocycle is preferably an aromatic ring, preferably an aromatic ring having 6 to 18 ring-constituting carbon atoms, and a benzene ring, naphthalene ring, anthracene ring, or phenanthrene ring. Examples thereof include a ring, a pyrene ring and a naphthacene ring. A benzene ring or a naphthalene ring is more preferable, and a benzene ring is particularly preferable. Examples of the aromatic heterocycle include a pyrimidine ring. The substituent that the aromatic ring or aromatic heterocycle may have, a halogen atom, a carboxyl group,
Cyano group, nitro group, carbamoyl group, sulfamoyl group, alkyl group, cycloalkyl group, alkoxy group, alkylthio group, acyl group, acyloxy group, alkyl-substituted carbamoyl group, alkyl-substituted sulfamoyl group, amide group, sulfonamide group, alkylsulfonyl Groups and alicyclic hydrocarbon groups may be mentioned. The alkyl group may have a branched or cyclic structure. The alkyl group may have a branch. The number of carbon atoms in the alkyl group is preferably 1-20, and 1-1
It is more preferably 5, more preferably 1 to 10, and most preferably 1 to 6. The alicyclic hydrocarbon group is preferably a cyclohexyl group.

A polyacrylic acid copolymer or polymethacrylic acid copolymer containing a repeating unit containing 2 to 4 aromatic rings or aromatic heterocycles in the side chains represented by the above formulas (I) and (II). The combination is a polyacrylic acid copolymer or polymethacrylic acid copolymer containing a tolan group in its side chain,
Alternatively, a polyacrylic acid copolymer or polymethacrylic acid copolymer containing a biphenyl group in the side chain is preferable, and a polyacrylic acid copolymer or polymethacrylic acid copolymer containing a tolan group is particularly preferable. .
Here, the tolan group means a group represented by the following formula.

[0042]

[Chemical 5]

In the above formula, R ⁰ and R ¹¹ independently of each other have the same meanings as the substituents which the aromatic ring or aromatic heterocycle described above may have. k and z are 0 to 3
Represents the integer.

The polyacrylic acid copolymer or polymethacrylic acid copolymer containing a tolan group will be described in detail below.

The polyacrylic acid copolymer or polymethacrylic acid copolymer containing a tolan group preferably contains a repeating unit containing a tolan group in a range of 5 to 80 mol%, and in a range of 10 to 70 mol%. It is more preferable to include. A polyacrylic acid copolymer and a polymethacrylic acid copolymer each containing a preferred tolan group are represented by the following formula (P
It is represented by A). (PA)-(AA) _x- (T) _y- (PA)-(MA) _x- (T) _{y- In the} formula, AA is a repeating unit derived from acrylic acid; and MA is methacrylic acid. Is a repeating unit derived from. T is a repeating unit containing a tolan group. x is 10 to 95 mol% (preferably 20 to 90)
Mol%, and particularly preferably 25 to 90 mol%). y is 5 to 90 mol% (preferably 10 to 80 mol%, particularly preferably 10 to 70 mol%). The repeating unit (T) containing a preferred tolan group is represented by the following formula (IA).

Formula (IA)

[Chemical 6]

Where L⁰Is -NH-, -O-, -O-
Alkylene group-, -O-alkylene group-CO-O- and
And an -O-alkylene group-O-
Represents a valent linking group, R², Ar¹, Ar², Ar³, A
r^Four, L², L³, L^Four, M and n are each the above general
R in formula (I)², Ar¹, Ar², Ar³, Ar^Four, L²,
L ³, L^Four, M, and n have the same meanings, and preferred ranges are also the same.
is there.

Examples of repeating units containing a tolan group in the side chain are shown below.

[0049]

[Chemical 7]

[0050]

[Chemical 8]

[0051]

[Chemical 9]

[0052]

[Chemical 10]

[0053]

[Chemical 11]

[0054]

[Chemical 12]

[0055]

[Chemical 13]

[0056]

[Chemical 14]

[0057]

[Chemical 15]

[0058]

[Chemical 16]

[0059]

[Chemical 17]

[0060]

[Chemical 18]

[0061]

[Chemical 19]

[0062]

[Chemical 20]

[0063]

[Chemical 21]

[0064]

[Chemical formula 22]

[0065]

[Chemical formula 23]

[0066]

[Chemical formula 24]

[0067]

[Chemical 25]

[0068]

[Chemical formula 26]

[0069]

[Chemical 27]

[0070]

[Chemical 28]

[0071]

[Chemical 29]

[0072]

[Chemical 30]

[0073]

[Chemical 31]

[0074]

[Chemical 32]

[0075]

[Chemical 33]

[0076]

[Chemical 34]

[0077]

[Chemical 35]

[0078]

[Chemical 36]

[0079]

[Chemical 37]

[0080]

[Chemical 38]

[0081]

[Chemical Formula 39]

[0082]

[Chemical 40]

[0083]

[Chemical 41]

[0084]

[Chemical 42]

[0085]

[Chemical 43]

[0086]

[Chemical 44]

[0087]

[Chemical formula 45]

[0088]

[Chemical formula 46]

[0089]

[Chemical 47]

[0090]

[Chemical 48]

[0091]

[Chemical 49]

[0092]

[Chemical 50]

The examples of the polyacrylic acid copolymer and the polymethacrylic acid copolymer containing a tolan group are shown below in order. The proportion of repeating units is mol%.

[0094] _{PA101 :-( AA) 60 - (T} -1) 40 - PA102 :-( AA) 70 - (T-1) 30 - PA103 :-( AA) 60 - (T-2) 40 - PA104: _{- (AA) 65 - (T} -7) 35 - PA105 :-( AA) 70 - (T-11) 30 - PA106 :-( AA) 80 - (T-14) 20 - PA107 :-( AA) 70 _{- (T-20) 30 -} PA108 :-( AA) 60 - (T-23) 40 - PA109 :-( AA) 70 - (T-25) 30 - PA110 :-( AA) 60 - (T-25 _{) 40 - PA111 :-( AA) 50} - (T-25) 50 - PA112 :-( AA) 70 - (T-26) 30 - PA113 :-( AA) 60 - (T-28) 40 - PA114: _{- (AA) 50 - (T} -32) 50 - PA115 :-( AA) 70 - (T-33) 30 - PA116 :-( AA) 60 - (T-33) 40 - PA117 :-( AA) 70 − _{(T-38) 30 - PA118} :-( AA) 60 - (T-38) 40 - PA119 :-( AA) 60 - (T-39) 40 - PA120 :-( AA) 60 - (T-41) _{40 - PA121 :-( AA) 60 -} (T-43) 40 -

[0095] _{PA201 :-( MA) 60 - (T} -1) 40 - PA202 :-( MA) 70 - (T-1) 30 - PA203 :-( MA) 60 - (T-2) 40 - PA204: _{- (MA) 65 - (T} -7) 35 - PA205 :-( MA) 70 - (T-11) 30 - PA206 :-( MA) 80 - (T-14) 20 - PA207 :-( MA) 70 _{- (T-20) 30 -} PA208 :-( MA) 60 - (T-23) 40 - PA209 :-( MA) 70 - (T-25) 30 - PA210 :-( MA) 60 - (T-25 _{) 40 - PA211 :-( MA) 50} - (T-25) 50 - PA212 :-( MA) 70 - (T-26) 30 - PA213 :-( MA) 60 - (T-28) 40 - PA214: _{- (MA) 50 - (T} -32) 50 - PA215 :-( MA) 70 - (T-33) 30 - PA216 :-( MA) 60 - (T-33) 40 - PA217 :-( MA) 70 − _{(T-38) 30 - PA218} :-( MA) 60 - (T-38) 40 - PA219 :-( MA) 60 - (T-39) 40 - PA220 :-( MA) 60 - (T-41) _{40 - PA221 :-( MA) 60 -} (T-42) 40 - PA222 :-( MA) 60 - (T-43) 40 -

A polymerizable group may be introduced into the acrylic acid copolymer (or polymethacrylic acid copolymer). When the above-mentioned acrylic acid copolymer (or polymethacrylic acid copolymer) having a polymerizable group is used as the liquid crystal alignment film and a liquid crystalline compound having a polymerizable group is used as the discotic liquid crystalline compound, a polyacrylic acid copolymer is obtained. (Or the polymethacrylic acid copolymer) and the liquid crystalline compound can be chemically bonded via the interface between the liquid crystal layer and the alignment film. Thereby, the durability of the liquid crystal layer using the alignment film can be improved. The polymerizable group is introduced into the acrylic acid copolymer (or methacrylic acid copolymer) as a repeating unit having a polymerizable group in the side chain, or an aromatic ring or an aromatic heterocycle is added in the side chain of 2 to 4 A polymerizable group can be introduced into each repeating unit. A repeating unit having a polymerizable group in the side chain and an aromatic ring or aromatic heterocycle in the side chain 2
The repeating units having 4 to 4 and a polymerizable group will be described in this order.

The polymerizable group is subjected to a polymerization reaction with the polymerizable group (Q) of the liquid crystal molecule described below to give the liquid crystal molecule and the polyacrylic acid copolymer (or polymethacrylic acid copolymer),
It can be chemically bonded via the interface between the liquid crystal layer and the liquid crystal alignment film. Therefore, the type of the polymerizable group is determined according to the type of the polymerizable group (Q) of the liquid crystal molecule described later.
As described below, the polymerizable group (Q) of the liquid crystal molecule is preferably an unsaturated polymerizable group (Q1 to Q7 in the examples described below), an epoxy group (Q8) or an aziridinyl group (Q9), More preferably a saturated polymerizable group,
Most preferably, they are ethylenically unsaturated polymerizable groups (Q1 to Q6). Similarly, the polymerizable group of the polyacrylic acid copolymer (or polymethacrylic acid copolymer) is also preferably an unsaturated polymerizable group, an epoxy group or an aziridinyl group, more preferably an unsaturated polymerizable group. Preferably
Most preferably, it is an ethylenically unsaturated polymerizable group.

It is preferable that the main chain and the polymerizable group are not directly linked but are linked via a linking group. Examples of linking groups include-
CO-, -CO-O-, -CO-NH-, -CO-NH
-Alkylene group-, -CO-NH-alkylene group-O
-, -CO-NH-alkylene group -CO-O-, -CO
-NH-alkylene group -O-CO-, -CO-NH-alkylene group -CO-NH-, -CO-alkylene group -O
-CO-, -CO-arylene group-O-alkylene group-
O-CO-, -CO-arylene group-O-alkylene group-O-, -CO-arylene group-O-alkylene group- and -CO-alkylene group-O-CO- are included (the left side is in the main chain. To the polymerizable group on the right side). The alkylene group may have a branched or cyclic structure. The number of carbon atoms of the alkylene group is preferably 1 to 30, more preferably 1 to 20, and 1 to
It is more preferably 15, and most preferably 1-12. The arylene group is preferably phenylene or naphthylene, more preferably phenylene, and most preferably p-phenylene. The arylene group may have a substituent. Examples of the substituent of the arylene group include a halogen atom (F, Cl, Br), carboxyl, cyano, nitro,
Carbamoyl, sulfamoyl, alkyl group, cycloalkyl group, alkoxy group, alkylthio group, acyl group,
It includes an acyloxy group, an alkyl-substituted carbamoyl group, an alkyl-substituted sulfamoyl group, an amide group, a sulfonamide group and an alkylsulfonyl group. The alkyl group may have a branch. The alkyl group preferably has 1 to 20 carbon atoms, more preferably has 1 to 15 carbon atoms, further preferably has 1 to 10 carbon atoms, and most preferably has 1 to 6 carbon atoms. The cycloalkyl group is preferably cyclohexyl. The alkoxy group may have a branch. The alkoxy group preferably has 1 to 20 carbon atoms,
It is more preferably 1 to 15, more preferably 1 to 10, and most preferably 1 to 6. The alkylthio group may have a branch.
The number of carbon atoms of the alkylthio group is preferably 1 to 20, more preferably 1 to 15, and 1 to 1
It is more preferably 0, and most preferably 1 to 6. The acyl group has preferably 2 to 20 carbon atoms, more preferably 2 to 15 carbon atoms, further preferably 2 to 10 carbon atoms, and most preferably 2 to 6 carbon atoms. The acyloxy group preferably has 2 to 20 carbon atoms, more preferably has 2 to 15 carbon atoms, and even more preferably has 2 to 10 carbon atoms. It is preferably 2 to 20, more preferably 2 to 15, even more preferably 2 to 10, and most preferably 2 to 6. The alkyl part of the alkyl-substituted carbamoyl group may further have a substituent (eg, an alkoxy group). The alkyl-substituted sulfamoyl group has preferably 2 to 20 carbon atoms, more preferably 2 to 15 carbon atoms, and 2 to 1 carbon atoms.
It is more preferably 0, and most preferably 2 to 6. The alkyl part of the alkyl-substituted sulfamoyl group may further have a substituent (eg, an alkoxy group). The amide group has preferably 2 to 20 carbon atoms, more preferably 2 to 15 carbon atoms, further preferably 2 to 10 carbon atoms, and most preferably 2 to 6 carbon atoms. The sulfonamide group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, still more preferably 1 to 10 carbon atoms, and most preferably 1 to 6 carbon atoms. The alkylsulfonyl group has preferably 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and 1 to 1 carbon atoms.
It is more preferably 0, and most preferably 1 to 6. The alkyl part of the alkylsulfonyl group is
Further, it may have a substituent (eg, an alkoxy group).

The side chain may have two or more polymerizable groups. The repeating unit having a polymerizable group on its side chain is preferably represented by the following formula (IB).

Formula (IB)

[Chemical 51]

In the formula (IB), L ¹¹ is a single bond, —CO—, —CO—NH—, —CO—NH-alkylene group—, —CO—NH-alkylene group —O—, —CO.
-NH-alkylene group -CO-O-, -CO-NH-alkylene group -O-CO-, -CO-NH-alkylene group -CO-NH-, -CO-alkylene group -O-CO-,
-CO-arylene group-O-alkylene group-O-CO
-, -CO-arylene group-O-alkylene group-O-,
It represents a linking group selected from the group consisting of -CO-arylene group-O-alkylene group- and -alkylene group-O-CO-. -CO-NH-alkylene group-, -CO-NH
-Alkylene group -O-, -CO-arylene group -O-alkylene group -O-CO-, -CO-arylene group -O-
Alkylene group -O-, -CO-arylene group -O-alkylene group- and -alkylene group -O-CO- are preferable, and -CO-NH-alkylene group -O-CO- is particularly preferable. The alkylene group may have a branched or cyclic structure. The number of carbon atoms in the alkylene group is 1 to 3
0 is preferable, 1-20 is more preferable, 1-15 is further preferable, 1-1
Most preferably, it is 2. The arylene group is preferably a phenylene group or a naphthylene group,
A phenylene group is more preferable, and a p-phenylene group is most preferable. The arylene group may have a substituent. Examples of the substituent of the arylene group are the same as the examples of the substituent of the aromatic ring in the general formulas (I) and (II). In the formula (IB), Q is
It is a polymerizable group. As described above, the polymerizable group is preferably the same group as the polymerizable group (Q) of the liquid crystal molecule. Below, the example of the repeating unit which has a polymeric group in a side chain is shown.

[0102]

[Chemical 52]

[0103]

[Chemical 53]

[0104]

[Chemical 54]

[0105]

[Chemical 55]

[0106]

[Chemical 56]

[0107]

[Chemical 57]

[0108]

[Chemical 58]

[0109]

[Chemical 59]

[0110]

[Chemical 60]

[0111]

[Chemical formula 61]

[0112]

[Chemical formula 62]

The polymerizable group (Q) is determined according to the type of polymerization reaction. Examples of the polymerizable group (Q) are shown below.

[0114]

[Chemical formula 63]

The polymerizable group is an unsaturated polymerizable group (Q1 to Q
7), epoxy group (Q8) or aziridinyl group (Q
9) is preferable, and ethylenically unsaturated polymerizable group (Q1 to Q6) is preferable.

Each of the first optically anisotropic layer and the second optically anisotropic layer contains at least one discotic liquid crystalline compound, but additionally contains a liquid crystal alignment accelerator. The liquid crystal aligning agent represented by the following general formula (III) is particularly preferable. When liquid crystal molecules are injected between two alignment films as in the general formula (III) (Hb-L ^5- ) _n B ¹ liquid crystal cell, the liquid crystal molecules have a free interface (air interface). Therefore, if the two alignment films are provided, the alignment control of the liquid crystal molecules is relatively easy. However, when only one alignment film is used, various alignment defects occur at the free interface of liquid crystal molecules. There is no alignment control force from the outside on the free interface, and it is very difficult to bring the liquid crystal molecules into a uniform alignment state without alignment defects in such a state. Furthermore, at the free interface, liquid crystal molecules are affected by external influences such as uneven evaporation rate of the coating solvent and dry air, and thus alignment defects are likely to occur. For example, discotic liquid crystal compound molecules (discotic liquid crystal molecules) are vertically aligned (homogeneous alignment).
At the free interface, the tilt angle of the optical axis was the same, and a state (dual domain alignment) in which two kinds of orientation forms in which the disc surfaces faced in opposite directions were mixed (dual domain orientation) was observed.
The compound in which the hydrophobic group (Hb) and the group having the excluded volume effect (B ¹ ) are linked as defined by the above formula (III) is used in the case of using liquid crystal molecules, particularly when using one alignment film. Since it has a function of controlling the alignment state of liquid crystal molecules on the air interface side, it is preferably used in the present invention.

The compound represented by the formula (III) can be unevenly distributed on the air interface side after being mixed with liquid crystal and applied. In order to be unevenly distributed on the air interface side, it is necessary to be incompatible with the liquid crystal, that is, to be phase separated from the liquid crystal. In the compound represented by the formula (III), the hydrophobic group (Hb) functions to cause phase separation with the liquid crystal. In addition, the hydrophobic group (H
When b) is a fluorine-substituted aliphatic group, clear phase separation occurs. Further, in order to promote the alignment of the liquid crystal, it is necessary to have a partial structure that is relatively rigid and has properties close to the molecular polarization characteristics of the liquid crystal. The group (B ¹ ) having an excluded volume effect corresponds to such a partial structure. The details of the mechanism by which the compound represented by the formula (III) functions as an orientation promoter are not clear, but the compound represented by the general formula (III) has a hydrophobic group (Hb) near the air interface. It can be presumed that the existence of the group (B ¹ ) having the excluded volume effect toward the air side and the group (B ¹ ) having the excluded volume effect toward the liquid crystal side contributes to the action as the orientation promoter.

In the above formula (III), the group (B ¹ ) having an excluded volume effect has at least three cyclic structures. At least three annular structures form a planar structure as a whole, and a part of the annular structures has a structure protruding like a pile on the liquid crystal side (for example, at least two rings are single-bonded or vinylene-bonded). Or when it includes a structure bound by an ethynylene bond). When the annular structure forms a planar structure as a whole, for a discotic liquid crystal compound (discotic liquid crystal compound),
A horizontal alignment effect or a vertical alignment effect is exhibited depending on whether the group (B ¹ ) having the excluded volume effect is hydrophilic or hydrophobic. The first optically anisotropic layer and the second
By containing the compound represented by the general formula (III), the optical anisotropic layers of the discotic liquid crystal compound in the first and second optical anisotropic layers are It is possible to more stably achieve the orientation in which the orientation angle is substantially 80 ° or more.

As described above, the electrostatic attractive force between molecules between the liquid crystal and the compound represented by the formula (III) and the repulsive force due to the excluded volume effect have the molecular structure of the compound, particularly the excluded volume effect. It can be freely controlled by changing the group (B ¹ ). That is, by properly selecting the type of the compound represented by the formula (III), the tilt angle of the liquid crystal molecule on the air interface side is not limited to the type of the liquid crystal molecule and can be arbitrarily stabilized. Controllable. Therefore, when the compound represented by the formula (III) is used as the liquid crystal alignment promoter, the liquid crystalline molecules can be more uniformly and stably aligned even at the free interface where the alignment film is not provided.

In the formula (III), Hb represents an aliphatic group having 6 to 40 carbon atoms or an aliphatic substituted oligosiloxanoxy group having 6 to 40 carbon atoms. Hb is preferably an aliphatic group having 6 to 40 carbon atoms, and is a fluorine-substituted aliphatic group having 6 to 40 carbon atoms or a branched aliphatic group having 6 to 40 carbon atoms. More preferably, it is a fluorine-substituted alkyl group having 6 to 40 carbon atoms or a branched alkyl group having 6 to 40 carbon atoms.

The aliphatic group represented by Hb is preferably a chain aliphatic group rather than a cyclic aliphatic group. The chain aliphatic group may have a branch. The number of carbon atoms of the aliphatic group is 7 to
It is preferably 35, more preferably 8 to 30, still more preferably 9 to 25, and 10
Most preferably, it is -20. Aliphatic groups include alkyl groups, substituted alkyl groups, alkenyl groups, substituted alkenyl groups, alkynyl groups and substituted alkynyl groups. An alkyl group, a substituted alkyl group, an alkenyl group and a substituted alkenyl group are preferable, and an alkyl group and a substituted alkyl group are more preferable. Examples of the substituent of the aliphatic group include halogen atom, hydroxyl group, cyano group, nitro group, alkoxy group, substituted alkoxy group (eg oligoalkoxy group), alkenyloxy group (eg vinyloxy), acyl group (eg , Acryloyl, methacryloyl), an acyloxy group (eg, acryloyloxy, benzoyloxy), a sulfamoyl group, an aliphatic substituted sulfamoyl group and an epoxyalkyl group (eg, epoxyethyl). As the substituent, a halogen atom is preferable, and a fluorine atom is more preferable. In the fluorine-substituted aliphatic group, the ratio of the fluorine atom substituting the hydrogen atom of the aliphatic group is preferably 50 to 100%, more preferably 60 to 100%, and 70 to
More preferably 100%, 80-100%
Is more preferable, and 85 to 100% is the most preferable.

The aliphatic substituted oligosiloxanoxy group preferably has 7 to 35 carbon atoms, and 8 to 3 carbon atoms.
It is more preferably 0, further preferably 9 to 25, and most preferably 10 to 20.
The aliphatic substituted oligosiloxanoxy group is represented by the following formula. R ^1- (Si (R ² ) ₂ -O) _q -In the formula, R ¹ represents a hydrogen atom, hydroxyl or an aliphatic group; R ² represents a hydrogen atom, an aliphatic group or an alkoxy group; and q Represents an integer of 1 to 12.
The aliphatic group represented by R ¹ and R ² is preferably a chain aliphatic group rather than a cyclic aliphatic group. The chain aliphatic group may have a branch. The number of carbon atoms in an aliphatic group is
1 to 12 is preferable, 1 to 8 is more preferable, 1 to 6 is further preferable, 1 to
4 is particularly preferable. The aliphatic group represented by R ¹ and R ² includes an alkyl group, a substituted alkyl group,
Included are alkenyl groups, substituted alkenyl groups, alkynyl groups and substituted alkynyl groups. An alkyl group, a substituted alkyl group, an alkenyl group and a substituted alkenyl group are preferable, and an alkyl group and a substituted alkyl group are more preferable. The aliphatic group represented by R ¹ and R ² may have a substituent, and examples of the substituent include a halogen atom, a hydroxyl group, a cyano group, a nitro group, an alkoxy group and a substituted alkoxy group. Group (eg, oligoalkoxy group), alkenyloxy group (eg, vinyloxy), acyl group (eg, acryloyl, methacryloyl), acyloxy group (eg, acryloyloxy, benzoyloxy), sulfamoyl group, aliphatic-substituted sulfamoyl group and epoxy Alkyl groups (eg, epoxyethyl) are included.

The alkoxy group represented by R ² may have a cyclic structure or a branch. The alkoxy group preferably has 1 to 12 carbon atoms, more preferably has 1 to 8 carbon atoms, further preferably has 1 to 6 carbon atoms, and further preferably has 1 to 4 carbon atoms. Below, the example of Hb is shown.

[0124] _{Hb1: n-C 16 H 33} - Hb2: n-C 20 H 41 - Hb3: n-C 6 H 13 -CH (n-C 4 H 9) -CH 2 -
_{CH 2 - Hb4: n-C} 12 H 25 - Hb5: n-C 18 H 37 - Hb6: n-C 14 H 29 - Hb7: n-C 15 H 31 - Hb8: n-C 10 H 21 - Hb9: _{n-C 10 H 21 -CH (} n-C 4 H 9) -CH 2 -
_{CH 2 - Hb10: n-C} 8 F 17 -

Hb11: n-C₈H₁₇− Hb12: CH (CH₃)₂-{C₃H₆-CH (C
H₃)}₃-C₂H_Four− Hb13: CH (CH₃)₂-{C₃H₆-CH (C
H₃)}₂-C₃H₆-C (CH ₃) = CH-CH₂− Hb14: n-C₈H₁₇-CH (n-C₆H₁₃) -CH₂
-CH₂− Hb15: n-C₆H₁₃-CH (C₂H_Five) -CH₂-CH
₂− Hb16: n-C₈F₁₇-CH (n-C_FourF₉) -CH₂− Hb17: n-C₈F₁₇-CF (n-C₆F₁₃) -CF₂
-CF₂− Hb18: n-C₃F₇-CF (CF₃) -CF₂− Hb19: Si (CH₃)₃-{Si (CH₃)₂-O}₆
-O- Hb20: Si (OC₃H₇) (C₁₆F₃₃) (C₂H_Four-S
O₂-NH-C₈F₁₇) -O-

In the above formula (III), L ⁵ represents a single bond or a divalent linking group. The divalent linking group is -alkylene group-, -fluorine-substituted alkylene group-, -O-,-
S -, - CO -, - NR -, - SO 2 - and is preferably a group selected from the group consisting of. R is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. L ⁵ is an -alkylene group-, -O-,
-S -, - CO -, - NR -, - SO 2 - and more preferably a divalent linking group selected from the group consisting of. R is preferably a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 15 carbon atoms, and having 1 hydrogen atom or 1 carbon atoms.
Most preferably, it is an alkyl group of ~ 12. The alkylene group or the fluorine-substituted alkylene group preferably has 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, further preferably 1 to 20 carbon atoms, and 1 to 15 carbon atoms. Further preferably, 1 to 1
Most preferably, it is 2. Hereinafter, examples of L ^5. The left side binds to Hb and the right side binds to B ¹ .

[0127] L10: single bond L11: -O- L12: -O-CO- L13: -CO-C 4 H 8 -O- L14: -O-C 2 H 4 -O-C 2 H 4 -O- L15: -S- L16: -N (n -C 12 H 25) - L17: -O-CH 2 CH 2 -N (n-C 3 H 7) -SO 2
_{- L18: -CF (CF 3)} - {O-CF 2 -CF (C
F ₃ )} ₃ -O-

In the above formula (III), n represents an integer of 2-12. n is preferably an integer of 2-9, more preferably an integer of 2-6, even more preferably 2, 3 or 4, and even more preferably 3 or 4. Most preferred.

In the above formula (III), B ¹ is an n-valent group having an excluded volume effect and containing at least three cyclic structures. B ¹ is preferably an n-valent group represented by the following formula (III-a). Formula ^{(III-a) (-Cy 1} -L 6 -) n Cy 2 In Formula (III-a), Cy ¹ represents a divalent cyclic group. Cy ¹ preferably represents a divalent aromatic hydrocarbon group or a divalent heterocyclic group, more preferably a divalent aromatic hydrocarbon group. The divalent aromatic hydrocarbon group means an arylene group and a substituted arylene group. Examples of the arylene group, phenylene group, indenylene group, naphthylene group, fluorenylene group, phenanthrenylene group,
An anthrylene group and a pyrenylene group are included. Phenylene groups and naphthylene groups are preferred. Examples of the substituent of the substituted arylene group include an aliphatic group, an aromatic hydrocarbon group, a heterocyclic group, a halogen atom, an alkoxy group (for example, a methoxy group, an ethoxy group, a methoxyethoxy group), an aryloxy group (for example, Phenoxy group), arylazo group (eg phenylazo group), alkylthio group (eg methylthio group, ethylthio group, propylthio group), alkylamino group (eg methylamino group, propylamino group), acyl group (eg acetyl group) , Propanoyl group, octanoyl group, benzoyl group), acyloxy group (for example, acetoxy group, pivaloyloxy group, benzoyloxy group), hydroxyl group, mercapto group, amino group, carboxyl group, sulfo group, carbamoyl group, sulfamoyl group and ureido group. Is included. When another aromatic hydrocarbon ring is bonded to the divalent aromatic hydrocarbon group through a single bond, a vinylene bond or an ethynylene bond as a substituent, a specific liquid crystal alignment promoting function is obtained as described above. To be Furthermore, Hb-L ⁵ - the equivalent to radicals may have as substituents.

The divalent heterocyclic group represented by Cy ¹ is 5
Having a 6-, or 7-membered heterocycle.
A 5-membered ring or a 6-membered ring is more preferable, and a 6-membered ring is the most preferable. As the hetero atom forming the hetero ring, a nitrogen atom, an oxygen atom and a sulfur atom are preferable. The heterocycle is preferably an aromatic heterocycle. The aromatic heterocycle is generally an unsaturated heterocycle. Unsaturated heterocycles having the most double bonds are more preferred. Examples of heterocycles include
Furan ring, thiophene ring, pyrrole ring, pyrroline ring, pyrrolidine ring, oxazole ring, isoxazole ring, thiazole ring, isothiazole ring, imidazole ring, imidazoline ring, imidazolidine ring, pyrazole ring, pyrazoline ring, pyrazolidine ring, triazole ring , A furazan ring, a tetrazole ring, a pyran ring, a thiyne ring, a pyridine ring, a piperidine ring, an oxazine ring, a morpholine ring, a thiazine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, a piperazine ring and a triazine ring.

The heterocycle may be condensed with another heterocycle, an aliphatic ring or an aromatic hydrocarbon ring. Examples of the condensed heterocycle include benzofuran ring, isobenzofuran ring, benzothiophene ring, indole ring, indoline ring, isoindole ring, benzoxazole ring, benzothiazole ring,
Indazole ring, benzimidazole ring, chromene ring,
Chroman ring, isochroman ring, quinoline ring, isoquinoline ring, cinnoline ring, phthalazine ring, quinazoline ring, quinoxaline ring, dibenzofuran ring, carbazole ring, xanthene ring, acridine ring, phenanthridine ring, phenanthroline ring, phenazine ring, phenoxazine ring , Thianthrene ring, indolizine ring, quinolidine ring, quinuclidine ring, naphthyridine ring, purine ring and pteridine ring. The divalent heterocyclic group may have a substituent. Examples of the substituent are the same as the examples of the substituent of the substituted arylene group. A divalent heterocyclic group is a heteroatom (for example,
It may be bonded to L ⁶ or (when L ⁶ is a single bond) to a cyclic group (Cy ² ) at the center of the molecule at the nitrogen atom of the piperidine ring). Further, the heteroatom to be bonded may form an onium salt (eg, oxonium salt, sulfonium salt, ammonium salt).

The cyclic structure of Cy ¹ and Cy ² described later is
You may form the planar structure as a whole. When the annular structure forms a planar structure (that is, a disc-shaped structure) as a whole, a specific liquid crystal alignment promoting function is obtained as described above. The following is an example of Cy ¹ . When a plurality of groups corresponding to Hb-L ⁵ — are bonded to a divalent aromatic hydrocarbon group or a divalent heterocyclic group, any one of them is Hb-L ⁵ — defined in the above formula. The rest is a substituent of a divalent aromatic hydrocarbon group or a divalent heterocyclic group.

[0133]

[Chemical 64]

[0134]

[Chemical 65]

[0135]

[Chemical formula 66]

[0136]

[Chemical formula 67]

[0137]

[Chemical 68]

[0138]

[Chemical 69]

[0139]

[Chemical 70]

In the formula (III-a), L⁶Is a single bond
Or -alkylene group-, -alkenylene group-, -alkyn
Nylene group-,-O-,-S-,-CO-,-NR-,-
SO ₂-And selected from the group consisting of combinations thereof
Is a divalent linking group. R is a hydrogen atom or a carbon atom
It represents an alkyl group having a child number of 1 to 30. L²Is -O-,
-S-, -CO-, -NR-, -SO₂-And those
A divalent linking group selected from the group consisting of
Preferably. R has 1 hydrogen atom or carbon atom
It is preferably an alkyl group of 20 to 20, and a hydrogen atom or
Or an alkyl group having 1 to 15 carbon atoms.
Especially preferred, having 1 to 12 hydrogen atoms or carbon atoms
Most preferably, it is an alkyl group. Above alkylene
The number of carbon atoms in the group is preferably 1 to 40, and 1
It is more preferable that it is -30, and it is 1-20
Is more preferable, and 1 to 15 is even more preferable.
Most preferably, it is 1 to 12. Al above
The number of carbon atoms of the kenylene group or alkynylene group is 2 to
It is preferably 40, more preferably 2 to 30
It is preferably 2 to 20, more preferably 2 to 20.
It is still more preferable that it is 15, and it is 2-12
Is most preferred. Below, L⁶For example: On the left
Cy¹To the right side Cy²Bind to.

L20: Single bond L21: -S- L22: -NH- L23: -NH-SO ₂ -NH- L24: -NH-CO-NH- L25: -SO ₂ -L26: -O-NH- L27. : -C≡C- L28: -CH = CH- S- L29: -CH 2 -O- L30: -N (CH 3) - L31: -CO-O-

In the formula (III-a), n is 2 to 1
Represents any integer of 2. n is preferably an integer of 2-9, more preferably an integer of 2-6, even more preferably 2, 3 or 4, and even more preferably 3 or 4. Most preferred.
In the formula (III-a), Cy ² is an n-valent cyclic group. Cy ² is preferably an n-valent aromatic hydrocarbon group or an n-valent heterocyclic group. Examples of the aromatic hydrocarbon ring of the aromatic hydrocarbon group represented by Cy ² include a benzene ring, an indene ring, a naphthalene ring, a fluorene ring, a phenanthrene ring, an anthracene ring and a pyrene ring. A benzene ring and a naphthalene ring are preferable, and a benzene ring is particularly preferable. The aromatic hydrocarbon group represented by Cy ² may have a substituent. Examples of the substituent include an aliphatic group, an aromatic hydrocarbon group, a heterocyclic group, a halogen atom, an alkoxy group (for example, a methoxy group, an ethoxy group, a methoxyethoxy group), an aryloxy group (for example, a phenoxy group), An arylazo group (for example, a phenylazo group),
Alkylthio group (eg, methylthio group, ethylthio group, propylthio group), alkylamino group (eg, methylamino group, propylamino group), arylamino group (eg, phenylamino group), acyl group (eg, acetyl group, propanoyl) Group, octanoyl group, benzoyl group), acyloxy group (eg, acetoxy group, pivaloyloxy group, benzoyloxy group), hydroxyl group, mercapto group, amino group, carboxyl group, sulfo group, carbamoyl group, sulfamoyl group and ureido group. Be done.

The heterocyclic group represented by Cy ² preferably has a 5-membered, 6-membered or 7-membered heterocyclic ring. A 5-membered ring or a 6-membered ring is more preferable, and a 6-membered ring is the most preferable.
As the hetero atom forming the hetero ring, a nitrogen atom, an oxygen atom and a sulfur atom are preferable. The heterocycle is preferably an aromatic heterocycle. The aromatic heterocycle is
Generally, it is an unsaturated heterocycle. Unsaturated heterocycles having the most double bonds are more preferred. Examples of the heterocycle, furan ring, thiophene ring, pyrrole ring, pyrroline ring, pyrrolidine ring, oxazole ring, isoxazole ring, thiazole ring, isothiazole ring, imidazole ring, imidazoline ring, imidazolidine ring, pyrazole ring, Pyrazoline ring, pyrazolidine ring, triazole ring, furazan ring, tetrazole ring, pyran ring, thiyne ring, pyridine ring, piperidine ring, oxazine ring, morpholine ring, thiazine ring,
It includes a pyridazine ring, a pyrimidine ring, a pyrazine ring, a piperazine ring and a triazine ring. A triazine ring is preferable, and a 1,3,5-triazine ring is particularly preferable. Another heterocycle, an aliphatic ring or an aromatic hydrocarbon ring may be condensed with the heterocycle. However, monocyclic heterocycles are preferred. An example of Cy ² is shown below.

[0144]

[Chemical 71]

[0145]

[Chemical 72]

[0146]

[Chemical formula 73]

[0147]

[Chemical 74]

The liquid crystal alignment promoter is a compound in which the above-mentioned hydrophobic group (Hb), linking group (L ⁵ ) and group (B ¹ ) having an excluded volume effect are combined. There is no particular limitation on these combinations. Examples of the liquid crystal alignment promoter represented by the general formula (III) are shown below.

[0149]

[Chemical 75]

[0150]

[Chemical 76]

[0151]

[Chemical 77]

[0152]

[Chemical 78]

[0153]

[Chemical 79]

[0154]

[Chemical 80]

[0155]

[Chemical 81]

[0156]

[Chemical formula 82]

[0157]

[Chemical 83]

[0158]

[Chemical 84]

[0159]

[Chemical 85]

[0160]

[Chemical 86]

[0161]

[Chemical 87]

[0162]

[Chemical 88]

[0163]

[Chemical 89]

[0164]

[Chemical 90]

[0165]

[Chemical Formula 91]

[0166]

[Chemical Formula 92]

[0167]

[Chemical formula 93]

[0168]

[Chemical 94]

[0169]

[Chemical 95]

[0170]

[Chemical 96]

[0171]

[Chemical 97]

[0172]

[Chemical 98]

[0173]

[Chemical 99]

[0174]

[Chemical 100]

[0175]

[Chemical 101]

[0176]

[Chemical 102]

[0177]

[Chemical 103]

[0178]

[Chemical 104]

[0179]

[Chemical 105]

[0180]

[Chemical formula 106]

[0181]

[Chemical formula 107]

[0182]

[Chemical 108]

[0183]

[Chemical 109]

[0184]

[Chemical 110]

[0185]

[Chemical 111]

[0186]

[Chemical 112]

[0187]

[Chemical 113]

[0188]

[Chemical 114]

[0189]

[Chemical 115]

[0190]

[Chemical formula 116]

[0191]

[Chemical 117]

[0192]

[Chemical 118]

[0193]

[Chemical formula 119]

[0194]

[Chemical 120]

Discotic liquid crystalline compounds are used for the first optically anisotropic layer and the second optically anisotropic layer, respectively.
The liquid crystalline molecules are preferably substantially uniformly aligned in the optically anisotropic layer, and more preferably fixed in a substantially uniformly aligned state. Is most preferably fixed. The alignment of the liquid crystal molecules is adjusted so that the angle between the in-plane slow axis of the optically anisotropic layer and the longitudinal direction of the transparent support is substantially 75 ° or 15 °. The term "substantial" in the present invention means ± 5 °, preferably ± 4 °. For example, substantially 75 ° means 75 ± 5.

The discotic liquid crystal compound preferably used in the present invention, that is, the discotic liquid crystal compound, is aligned substantially perpendicular to the surface of the transparent support (average tilt angle in the range of 50 to 90 °). It is preferable. Discotic liquid crystalline compounds have been reported in various literatures (C. Destrade et a
l., Mol. Crysr. Liq. Cryst., vol. 71, page 111 (19
81) ； Chemical Society of Japan, Quarterly Chemistry Review, No. 22, Liquid Crystal Chemistry, Chapter 5, Chapter 10, Section 2 (1994); B. Kohne et
al., Angew. Chem. Soc. Chem. Comm., page 1794 (198
5); J. Zhang et al., J. Am. Chem. Soc., Vol. 116, p.
age 2655 (1994)). Regarding the polymerization of discotic liquid crystalline compounds, JP-A-8-2728
4 publication. In order to fix the discotic liquid crystal molecule by polymerization, it is necessary to bond a polymerizable group as a substituent to the discotic core of the discotic liquid crystal molecule. However, when the polymerizable group is directly bonded to the discotic core, it becomes difficult to maintain the alignment state in the polymerization reaction. Therefore, a linking group is introduced between the discotic core and the polymerizable group. Therefore, the discotic liquid crystal molecule having a polymerizable group is preferably a compound represented by the following formula (IV).

Formula (IV) D ¹ (-L-P ¹ ) n In the formula, D ¹ represents a disk-shaped core portion, L represents a divalent linking group, P ¹ represents a polymerizable group, and n Represents an integer of 4 to 12. Examples of the disk-shaped core (D ¹ ) in the above formula (IV) are shown below. In each of the following examples, LP ¹ (or P ¹ L) means a combination of a divalent linking group (L) and a polymerizable group (P ¹ ).

[0198]

[Chemical 121]

[0199]

[Chemical formula 122]

[0200]

[Chemical 123]

[0201]

[Chemical formula 124]

[0202]

[Chemical 125]

[0203]

[Chemical formula 126]

[0204]

[Chemical 127]

In the above formula (IV), the divalent linking group (L) is composed of an alkylene group, an alkenylene group, an arylene group, —CO—, —NH—, —O—, —S— and a combination thereof. It is preferably a divalent linking group selected from the group. The divalent linking group (L) is an alkylene group, an alkenylene group, an arylene group, -CO-, -NH.
A group in which at least two divalent groups selected from the group consisting of-, -O- and -S- are combined is more preferable. The divalent linking group (L) is most preferably a group in which at least two divalent groups selected from the group consisting of an alkylene group, an alkenylene group, an arylene group, -CO- and -O- are combined. The alkylene group preferably has 1 to 12 carbon atoms. The alkenylene group preferably has 2 to 12 carbon atoms.
The arylene group preferably has 6 to 10 carbon atoms. The alkylene group, alkenylene group and arylene group may have a substituent (eg, an alkyl group, a halogen atom, cyano, an alkoxy group, an acyloxy group).

Examples of the divalent linking group (L) are shown below. The left side is bonded to the discotic core (D ¹ ) and the right side is bonded to the polymerizable group (P ¹ ). AL means an alkylene group or an alkenylene group, and AR means an arylene group. L41: -AL-CO-O-AL- L42: -AL-CO-O-AL-O- L43: -AL-CO-O-AL-O-AL- L44: -AL-CO-O-AL- O-CO- L45: -CO-AR-O-AL- L46: -CO-AR-O-AL-O- L47: -CO-AR-O-AL-O-CO- L48: -CO-NH- AL-L49: -NH-AL-O- L50: -NH-AL-O-CO-

L51: -O-AL- L52: -O-AL-O- L53: -O-AL-O-CO- L54: -O-AL-O-CO-NH-AL- L55: -O- AL-S-AL- L56: -O-CO-AL-AR-O-AL-O-CO- L57: -O-CO-AR-O-AL-CO- L58: -O-CO-AR-O -AL-O-CO- L59: -O-CO-AR-O-AL-O-AL-O-C
O-L60: -O-CO-AR-O-AL-O-AL-OA
L-O-CO- L61: -S-AL- L62: -S-AL-O- L63: -S-AL-O-CO- L64: -S-AL-S-AL- L65: -S-AR -AL-

The polymerizable group (P ¹ ) of the above formula (IV) is determined according to the type of polymerization reaction. Examples of the polymerizable group (P ¹ ) are shown below.

[0209]

[Chemical 128]

[0210]

[Chemical formula 129]

[0211]

[Chemical 130]

[0212]

[Chemical 131]

[0213]

[Chemical 132]

[0214]

[Chemical 133]

The polymerizable group (P) is an unsaturated polymerizable group (P
1, P2, P3, P7, P8, P15, P16, P1
7) or an epoxy group (P6, P18) is preferable, and an unsaturated polymerizable group is more preferable,
Ethylenically unsaturated polymerizable group (P1, P7, P8, P1
5, P16, P17) is most preferable.

In the formula (IV), n is an integer of 4-12. The specific number is determined according to the type of discotic core (D). The combination of a plurality of L and P may be different, but is preferably the same. Two or more kinds of discotic liquid crystal molecules (for example, a molecule having an asymmetric carbon atom in a divalent linking group and a molecule having no asymmetric carbon atom) may be used in combination.

For the first and second optically anisotropic layers, a coating solution containing the following polymerizable initiator and other additives together with a liquid crystal compound was applied onto the first and second liquid crystal alignment films, respectively. It can be formed by applying to. An organic solvent is preferably used as the solvent used for preparing the coating liquid. Examples of organic solvents include amides (eg N, N-dimethylformamide), sulfoxides (eg dimethylsulfoxide), heterocyclic compounds (eg pyridine), hydrocarbons (eg benzene, hexane), alkyl halides (eg , Chloroform, dichloromethane), esters (eg, methyl acetate, butyl acetate),
Ketones (eg acetone, methyl ethyl ketone), ethers (eg tetrahydrofuran, 1,2-dimethoxyethane) are included. Alkyl halides and ketones are preferred. You may use together 2 or more types of organic solvents. The coating liquid is applied by a known method (for example, extrusion coating method, direct gravure coating method, reverse gravure coating method, die coating method).
Can be implemented by

The aligned liquid crystal molecules are fixed while maintaining the aligned state. The immobilization is preferably performed by a polymerization reaction of the polymerizable group (P) introduced into the liquid crystal molecule. The polymerization reaction includes a thermal polymerization reaction using a thermal polymerization initiator and a photopolymerization reaction using a photopolymerization initiator. Photopolymerization is preferred. Examples of the photopolymerization initiator include α-carbonyl compounds (described in US Pat. Nos. 2,367,661 and 2,367,670) and acyloin ethers (US Pat. No. 244).
8828 specification), α-hydrocarbon substituted aromatic acyloin compound (US Pat. No. 2,722,512 specification), polynuclear quinone compound (US Pat. No. 3,046,127),
No. 2951758), a combination of a triarylimidazole dimer and p-aminophenyl ketone (described in US Pat. No. 3,549,367), an acridine and a phenazine compound (JP-A-60-105).
667 publication, US Pat. No. 4,239,850 specifications)
And oxadiazole compounds (U.S. Pat.
No. 0 specification description) is included.

The amount of the photopolymerization initiator used is preferably 0.01 to 20% by mass of the solid content of the coating liquid, and is 0.5.
It is more preferable that the content is ˜5% by mass. Ultraviolet light is preferably used for the light irradiation for polymerizing the liquid crystal molecules. Irradiation energy is 20 mJ / cm ^{2 to} 50 J / c
m ² is preferable, and 100 to 800 mJ / cm ²
Is more preferable. Light irradiation may be carried out under heating conditions in order to accelerate the photopolymerization reaction.

The thickness of the first and second optically anisotropic layers is preferably 0.1 to 10 μm and 0.5 to 10 μm.
More preferably, it is 5 μm.

The material of the transparent support is not particularly limited, and a glass plate or a polymer film can be used, but it is preferable to use the polymer film from the viewpoint of thinning and weight saving. In particular, it is preferable to use a polymer film having a small wavelength dispersion. Further, a transparent support having a small optical anisotropy is preferable. Here, that the support is transparent means that the light transmittance is 80% or more. Small wavelength dispersion means specifically Re40
The 0 / Re700 ratio is preferably less than 1.2. The small optical anisotropy specifically means that the in-plane retardation (Re) is preferably 20 nm or less, more preferably 10 nm or less. The long transparent support has a roll shape or a rectangular sheet shape. It is preferable that the first and second optically anisotropic layers are laminated using a roll-shaped transparent support and then cut into a required size.

Examples of polymers include cellulose esters,
Included are polycarbonates, polysulfones, polyether sulfones, polyacrylates and polymethacrylates. Cellulose esters are preferred, acetyl cellulose is more preferred, and triacetyl cellulose is most preferred. The polymer film is preferably formed by the solvent casting method. The thickness of the transparent support is
It is preferably 20 to 500 μm, and 50 to 200
More preferably, it is μm. In order to improve the adhesion between the transparent support and the layer (adhesion layer, vertical liquid crystal alignment film or optically anisotropic layer) provided thereon, the transparent support is subjected to a surface treatment (eg glow discharge treatment, corona discharge treatment). , Ultraviolet (UV) treatment, flame treatment) may be performed. An adhesive layer (undercoat layer) may be provided on the transparent support.

For convenience of explanation, the mode of the retardation plate which makes the incident light a right-handed circularly polarized light is shown, but it goes without saying that a mode of making a left-handed circularly polarized light is also included in the present invention. In the aspect of left circularly polarized light, the longitudinal direction of the long transparent support and the slow axis of the first optically anisotropic layer having a phase difference of π are −75 °,
The first and second optical anisotropic layers are laminated at an angle of −15 ° with the slow axis of the second optical anisotropic layer having a phase difference of π / 2. In the retardation plate of this aspect, the rubbing axis of the first liquid crystal alignment film is set to 1 with respect to the longitudinal direction of the transparent support.
It can be manufactured by setting the angle to 5 ° and setting the rubbing axis of the second liquid crystal alignment film to −15 °.

The retardation plate of the present invention is used as a λ / 4 plate in a reflective liquid crystal display device, a λ / 4 plate used as a pickup for writing on an optical disk, or a λ / plate used as an antireflection film. Particularly preferably, the four plates can be used. The λ / 4 plate is generally used as a circularly polarizing plate combined with a polarizing film. Therefore, when configured as a circularly polarizing plate that combines a retardation plate and a polarizing film,
It can be easily incorporated in a device such as a reflective liquid crystal display device. When the retardation plate of the present invention is used together with a polarizing film in a reflective liquid crystal display device, it is possible to reduce the bluish tint that occurs during black display. Further, the retardation plate of the present invention can be stored and transported in a roll state, and when laminated with a polarizing film, it can be continuous by roll-to-roll, so that a circularly polarizing plate can be easily manufactured.

The circularly polarizing plate of the present invention comprises the retardation plate of the present invention and a polarizing film. The polarizing film is
The transparent support is laminated below the transparent support (on the side opposite to the first and second optically anisotropic layers) so that the longitudinal direction of the transparent support and the absorption axis are substantially aligned with each other. That is, the circularly polarizing plate of the present invention has a polarizing film having a polarizing axis in a direction substantially perpendicular to the longitudinal direction of the transparent support.

The polarizing film used in the present invention includes an iodine type polarizing film, a dye type polarizing film using a dichroic dye, and a polyene type polarizing film. The iodine type polarizing film and the dye type polarizing film are
Generally, it is manufactured using a polyvinyl alcohol film. The transmission axis of the polarizing film corresponds to the direction perpendicular to the stretching direction of the film. The polarizing film generally has protective films on both sides. However, in the present invention, the transparent support can function as a protective film on one side of the polarizing film. When a protective film is used separately from the transparent support, a cellulose ester film having high optical isotropy, particularly a triacetyl cellulose film is preferably used as the protective film.

The circularly polarizing plate of the present invention functions as a wide band λ / 4 plate. Here, the broadband λ / 4 plate is specifically a retardation value / wavelength value measured at wavelengths of 450 nm, 550 nm and 650 nm, which are all 0.
It means within the range of 2 to 0.3. The retardation value / wavelength value is preferably in the range of 0.21 to 0.29, more preferably in the range of 0.22 to 0.28, and in the range of 0.23 to 0.27. It is more preferably within the range, and most preferably within the range of 0.24 to 0.26.

[0228]

EXAMPLES The present invention will be described in more detail with reference to the following examples. The materials, reagents, ratios, operations and the like shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below. Example 1 Thickness 100 μm, width 500 mm, length 50
An optically isotropic roll-like triacetylcellulose film of 0 m was used as a transparent support. A diluting liquid of a liquid crystal alignment film (polymer having the following structural formula) was continuously applied to one surface of a transparent support to form an orthogonal liquid crystal alignment film of 0.5 μm in thickness. Then, rubbing treatment was continuously carried out in the direction of 16 ° on the right side with respect to the longitudinal direction of the transparent support.

Polymer for orthogonal liquid crystal alignment film (PA-11
6)

[Chemical 134]

On the liquid crystal alignment film, a coating solution having the following composition was continuously applied using a bar coater, dried, and heated (alignment ripening), and further irradiated with ultraviolet rays to a thickness of 1.6 μm.
The optically anisotropic layer (A) was formed. The optically anisotropic layer had a slow axis in the direction of 76 ° with respect to the longitudinal direction of the transparent support. The retardation value at 550 nm was 224 nm. The optical axis is parallel to the rubbing axis,
The direction was 16 ° to the right with respect to the longitudinal direction of the transparent support.

[0231]   Composition of coating liquid for optically anisotropic layer (A)   The following discotic liquid crystalline molecule (1) 32.6% by mass   3.2% by mass of the following modified trimethylolpropane triacrylate   The following sensitizer 0.4 mass%   1.1% by mass of the following photopolymerization initiator   The following vertical alignment promoter 0.5 mass%   Methyl ethyl ketone 62.2% by mass

Discotic liquid crystalline compound (1)

[Chemical 135]

Modified trimethylolpropane triacrylate

[Chemical 136]

Sensitizer

[Chemical 137]

Photopolymerization initiator

[Chemical 138]

Vertical alignment promoter

[Chemical 139]

Example 2 Thickness 100 μm, Width 500 m
An optically isotropic roll-shaped triacetylcellulose film having a length of m and a length of 500 m was used as a transparent support. A diluting liquid of a liquid crystal alignment film (polymer having the following structural formula) was continuously applied to one surface of a transparent support to form an orthogonal liquid crystal alignment film of 0.5 μm in thickness. Then, rubbing treatment was continuously carried out in the direction of 16 ° on the right side with respect to the longitudinal direction of the transparent support.

Polymer for orthogonal liquid crystal alignment film

[Chemical 140]

On the liquid crystal alignment film, a coating solution having the following composition was continuously applied using a bar coater, dried, and heated (alignment ripening), and further irradiated with ultraviolet rays to a thickness of 1.6 μm.
The optically anisotropic layer (B) was formed. The optically anisotropic layer had a slow axis parallel to the rubbing direction, that is, the optically anisotropic layer had a slow axis in the direction of 16 ° with respect to the longitudinal direction of the transparent support. Retardation value at 550 nm is 1
It was 12 nm. The optical axis was parallel to the rubbing axis, and was at a right angle of 16 ° with respect to the longitudinal direction of the transparent support.

[0240]   Composition of coating liquid for optically anisotropic layer (B)   20.8% by mass of the above discotic liquid crystal compound (1)   2.1% by mass of the above modified trimethylolpropane triacrylate   The above sensitizer (1) 0.3% by mass   The above photopolymerization initiator (1) 0.7% by mass   The above vertical alignment promoter (1) 0.3% by mass   Methyl ethyl ketone 75.8 mass%

[Embodiment 3] Thickness 100 μm, width 500 m
An optically isotropic roll-shaped triacetylcellulose film having a length of m and a length of 500 m was used as a transparent support. A diluting solution of the alignment film (polymer having the following structural formula) was continuously applied on one surface of the transparent support to form a 0.8 μm-thick orthogonal alignment film. Next, left hand 16 ° to the longitudinal direction of the transparent support
The rubbing process was continuously performed in the direction of.

Orthogonal alignment film (PA-110)

[Chemical 141]

On the alignment film, a coating solution having the following composition was continuously applied using a bar coater, dried, and heated (alignment ripening), and further irradiated with ultraviolet rays to give an optical difference of 2.8 μm in thickness. An anisotropic layer (A) was formed. The optically anisotropic layer had a slow axis in the direction of 74 ° with respect to the longitudinal direction of the transparent support. The retardation value at 550 nm is 22.
It was 4 nm.

[0244]   Composition of coating liquid for optically anisotropic layer (A)   The following discotic liquid crystalline molecule (2) 36.9 mass%   The above modified trimethylolpropane triacrylate 8.2% by mass   The following photopolymerization initiator 3.0 mass%   The following vertical alignment promoter 1.0 mass%   Methyl ethyl ketone 50.9 mass%

Discotic liquid crystal compound (2)

[Chemical 142]

Photopolymerization initiator

[Chemical 143]

Vertical alignment promoter

[Chemical 144]

Example 4 The retardation plate prepared in Example 1 was continuously coated with the diluent for the alignment film used in Example 2 on the optically anisotropic layer to form an alignment film. Then, on the alignment film, the right hand 58 with respect to the slow axis of the optically anisotropic layer (A) was used.
The rubbing treatment was performed so that the angle was 0 ° and the left-hand side was 16 ° with respect to the longitudinal direction of the retardation plate manufactured in Example 1.
Next, the coating liquid of the liquid crystalline compound used in Example 2 is continuously applied on the alignment film by using a bar coater, dried, and heated (alignment ripening), and further irradiated with ultraviolet rays to a thickness. An 0.8 μm optically anisotropic layer (B) was formed. The optical axis was in the direction of 74 ° to the right with respect to the longitudinal direction of the transparent support.

Example 5 The retardation plate prepared in Example 3 was continuously coated with the diluent for the alignment film used in Example 2 on the optically anisotropic layer to form an alignment film. Then, on the alignment film, the right hand 58 with respect to the slow axis of the optically anisotropic layer (A) was used.
The rubbing treatment was performed so that the angle was 16 ° and the left-hand side was 16 ° with respect to the longitudinal direction of the retardation plate manufactured in Example 3.
Next, the coating liquid of the liquid crystalline compound used in Example 2 is continuously applied on the alignment film by using a bar coater, dried, and heated (alignment ripening), and further irradiated with ultraviolet rays to a thickness. An 0.85 μm optically anisotropic layer (B) was formed.

[Comparative Example 1] An alignment film was formed using the same diluent as in Example 2. Then, rubbing treatment was continuously carried out in the direction of 74 ° to the left with respect to the longitudinal direction of the transparent support. A coating liquid having the same composition as in Example 1 was continuously applied onto the alignment film using a bar coater, dried, and heated (alignment ripening), and further irradiated with ultraviolet rays to a thickness of 2.8.
An optically anisotropic layer (A) having a thickness of μm was formed. The optically anisotropic layer had a slow axis in the direction of 74 ° with respect to the longitudinal direction of the transparent support. The retardation value at 550 nm was 225 nm. The diluent for the alignment film used in Example 2 was continuously applied to the retardation plate on the optically anisotropic layer (A) to form an alignment film. Then, on the alignment film,
The rubbing treatment was performed so that the right hand was 58 ° with respect to the slow axis of the optically anisotropic layer (A) and the left hand was 16 ° with respect to the longitudinal direction of the retardation plate. Next, the coating liquid of the liquid crystalline compound used in Example 2 is continuously applied on the alignment film by using a bar coater, dried, and heated (alignment ripening), and further irradiated with ultraviolet rays to a thickness. An 0.8 μm optically anisotropic layer (B) was formed. The retardation value of the optically anisotropic layer (B) was 113 nm, and the crossing angle between the two anisotropic layers was 58 °.

[Comparative Example 2] A retardation plate was formed in the same manner as in Example 4, except that the vertical alignment promoter was omitted from the optically anisotropic layers (A) and (B). At that time, the crossing angle between the two anisotropic layers was adjusted to 58 °, but the retardation value of the optically anisotropic layer (A) was 18 °.
At 0 nm, the retardation value of the optically anisotropic layer (B) was 73 nm, and it did not have the optical performance as a λ / 4 plate. In addition, both of the two anisotropic layers had numerous optical defects.

[Example 6: Evaluation of retardation plate] Example 4,
5 and Comparative Examples 1 and 2, a polarizing plate comprising a polarizing film and a protective film was used so that the angle between the polarizing axis of the polarizing film and the longitudinal direction of the retardation plate was 90 °, that is, roll to roll. A laminated circularly polarizing plate was produced by. Light from the polarizing film side of the obtained circularly polarizing plate (measurement wavelength is 450 nm,
550 nm and 650 nm) and the phase difference (retardation value: Re) of the light that passed through was measured. The results are shown in the table below

[0253]

[Table 1]

As shown in the table, it is understood that the retardation plates produced in Examples 4 and 5 exhibit a retardation of π / 2 especially in the short wavelength region. The retardation plates produced in Comparative Examples 1 and 2 are
The alignment state of the liquid crystal was poor and many alignment defects were observed. It can be seen that the phase difference is also small in all wavelength ranges.

[0255]

According to the present invention, an alignment film is applied on a long transparent support, and the alignment film is applied in the longitudinal direction of the transparent support.
By rubbing in the direction of 15 ° or 15 ° and then forming an optically anisotropic layer containing liquid crystal molecules, it is possible to manufacture a λ / 4 plate having a broad band in the short wavelength region. When used in a reflective liquid crystal display device, a satisfactory image can be displayed without being bluish even when displayed in black. Further, an alignment film is coated on a long transparent support, and rubbing is performed at −15 ° or 15 ° with respect to the longitudinal direction of the transparent support, and then an optical anisotropy containing liquid crystal molecules is contained. By forming the layer, a retardation plate that can be bonded to the polarizing film by roll-to-roll is obtained, and since the bonding with the polarizing film can be continuously performed in a roll state, the circularly polarizing plate can be easily manufactured.

According to the present inventor, it is possible to provide a retardation plate that functions as a retardation plate in a wide band (visible light wavelength range), can be thinned, and can be manufactured easily and stably. it can. Further, according to the present invention, it is possible to provide a circularly polarizing plate that functions as a circularly polarizing plate in a wide band (visible light wavelength region), can be thinned, and can be manufactured easily and stably. Further, the present invention is
Easily and stably manufacture retardation plates and circularly polarizing plates that function well in a wide band (visible wavelength range) and can be thinned by stably controlling the orientation of liquid crystal compound molecules. It is possible to provide a method of manufacturing a retardation plate and a circularly polarizing plate which can be performed.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a basic configuration of a retardation plate of the present invention.

FIG. 2 is a schematic view showing a typical constitution of the circularly polarizing plate of the present invention.

[Explanation of symbols]

S Long transparent support s Longitudinal direction of transparent support A first optically anisotropic layer a In-plane slow axis of the first optically anisotropic layer B second optically anisotropic layer b In-plane slow axis of the second optically anisotropic layer c1 Discotic liquid crystalline compound molecule c2 Discotic liquid crystalline compound molecule P Polarizing film p Polarization axis of polarizing film angle between α a and s angle between β b and s γ angle between a and b ra The rubbing axis of the liquid crystal alignment film of the first optically anisotropic layer rb rubbing axis of the liquid crystal alignment film of the second optically anisotropic layer

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2H049 BA02 BA03 BA06 BA42 BB03                       BB49 BC01 BC04 BC05 BC21                       BC22                 2H091 FA11 FA12 FA14Z FB02                       FC25 FD06 GA01 GA06 LA12

Claims (6)

[Claims] 1. A first optically anisotropic layer comprising a long transparent support and a vertically aligned discotic liquid crystal compound above the transparent support, and having a retardation of substantially π at a measurement wavelength of 550 nm. And a second optically anisotropic layer containing a vertically aligned discotic liquid crystalline compound and having a retardation of substantially π / 2 at a measurement wavelength of 550 nm, and a discotic shape of the first optically anisotropic layer. A first liquid crystal alignment film having a rubbing axis for vertically aligning the liquid crystal compound and determining an azimuth angle of the optical axis, and vertically aligning the discotic liquid crystal compound of the second optically anisotropic layer and the optical axis. A second liquid crystal alignment film having a rubbing axis that determines the azimuth angle of
The angle between the in-plane slow axis of the optically anisotropic layer and the longitudinal direction of the transparent support is substantially 75 °, and the in-plane slow axis of the second optically anisotropic layer is The angle with the longitudinal direction of the transparent support is substantially 15 °, the slow axis in the plane of the second optically anisotropic layer and the slow axis in the plane of the first optically anisotropic layer. The angle with the phase axis is substantially 60 °, and the discotic liquid crystal compound of the first optically anisotropic layer has an optical axis substantially orthogonal to the rubbing axis of the first liquid crystal alignment film. And the discotic liquid crystal compound of the second optically anisotropic layer is vertically aligned in a direction in which the optical axis is substantially parallel to the rubbing axis of the second liquid crystal alignment film. A retardation plate characterized by being present. 2. A first optically anisotropic layer containing a long transparent support and a vertically aligned discotic liquid crystal compound above the transparent support, and having a retardation of substantially π at a measurement wavelength of 550 nm. And a second optically anisotropic layer containing a vertically aligned discotic liquid crystalline compound and having a retardation of substantially π / 2 at a measurement wavelength of 550 nm, and a discotic shape of the first optically anisotropic layer. A first liquid crystal alignment film having a rubbing axis for vertically aligning the liquid crystal compound and determining an azimuth angle of the optical axis, and a vertical alignment of the discotic liquid crystal compound of the second optically anisotropic layer and the optical axis. A second liquid crystal alignment film having a rubbing axis that determines the azimuth angle of
The angle between the in-plane slow axis of the optically anisotropic layer and the longitudinal direction of the transparent support is substantially 75 °, and the in-plane slow axis of the second optically anisotropic layer is The angle with the longitudinal direction of the transparent support is substantially 15 °, the slow axis in the plane of the second optically anisotropic layer and the slow axis in the plane of the first optically anisotropic layer. The angle with the phase axis is substantially 60 °, the angle between the rubbing axis of the first liquid crystal alignment film and the longitudinal direction of the transparent support is substantially −15 °, and the second A retardation plate, wherein the angle between the rubbing axis of the liquid crystal alignment film and the longitudinal direction of the transparent support is substantially 15 °. 3. A step of forming a first liquid crystal alignment film having a rubbing axis having an angle of substantially −15 ° with the longitudinal direction of the transparent support above the elongated transparent support. ,
A layer containing a discotic liquid crystalline compound is formed on the first liquid crystal alignment film, and the discotic liquid crystalline compound is vertically aligned in a direction in which an optical axis is substantially perpendicular to the rubbing axis, The step of forming the first optically anisotropic layer having a phase difference of substantially π at a measurement wavelength of 550 nm and the angle between the transparent support and the longitudinal direction of the transparent support are substantially 15 A step of forming a second liquid crystal alignment film having a rubbing axis of 0 °, a layer containing a discotic liquid crystal compound is formed on the second liquid crystal alignment film, and the discotic liquid crystal compound is added to the layer. A second optical anisotropy in which the optical axis of the second liquid crystal alignment film is orthogonally oriented at an azimuth angle substantially parallel to the rubbing axis, and the phase difference at a measurement wavelength of 550 nm is substantially π / 2. Of the phase difference plate including the step of forming a layer Production method. 4. A first optically anisotropic layer containing a vertically aligned discotic liquid crystalline compound and having a phase difference of substantially π at a measurement wavelength of 550 nm, and a vertically aligned discotic liquid crystalline compound. A second optically anisotropic layer having a phase difference of substantially π / 2 at a measurement wavelength of 550 nm;
A first liquid crystal alignment film having a rubbing axis that vertically aligns the discotic liquid crystalline compound of the first optically anisotropic layer and determines the azimuth angle of the optical axis; and the second optically anisotropic layer. A circularly polarizing plate having a polarizing film and a second liquid crystal alignment film having a rubbing axis that determines the azimuth angle of the optical axis while vertically aligning the discotic liquid crystalline compound, wherein the first optical anisotropy is obtained. The angle between the in-plane slow axis of the layer and the absorption axis of the polarizing film is substantially 75 °, and the in-plane slow axis of the second optically anisotropic layer and the absorption axis of the polarizing film are And the angle between the in-plane slow axis of the second optically anisotropic layer and the in-plane slow axis of the first optically anisotropic layer is substantially 15 °. Is 60 °, and the discotic liquid crystal compound of the first optically anisotropic layer has an optical axis substantially perpendicular to the rubbing axis of the first liquid crystal alignment film. And the discotic liquid crystal compound of the second optically anisotropic layer is vertically aligned in a direction in which the optical axis is substantially parallel to the rubbing axis of the second liquid crystal alignment film. A circularly polarizing plate characterized by having. 5. A first optically anisotropic layer containing a vertically aligned discotic liquid crystalline compound and having a phase difference of substantially π at a measurement wavelength of 550 nm, and a vertically aligned discotic liquid crystalline compound. A second optically anisotropic layer having a phase difference of substantially π / 2 at a measurement wavelength of 550 nm;
A first liquid crystal alignment film having a rubbing axis that vertically aligns the discotic liquid crystalline compound of the first optically anisotropic layer and determines the azimuth angle of the optical axis; and the second optically anisotropic layer. A circularly polarizing plate comprising a polarizing film and a second liquid crystal alignment film having a rubbing axis that determines the azimuth angle of the optical axis while vertically aligning the discotic liquid crystalline compound, the first optical anisotropic film The angle between the in-plane slow axis of the anisotropic layer and the absorption axis of the polarizing film is substantially 75 °, and the in-plane slow axis of the second optically anisotropic layer and the absorption of the polarizing film are And an angle between the in-plane slow axis of the second optically anisotropic layer and the in-plane slow axis of the first optically anisotropic layer is substantially 15 °. The angle is substantially 60 °, the angle between the rubbing axis of the first liquid crystal alignment film and the absorption axis of the polarizing film is substantially −15 °, and Circularly polarizing plate, characterized in that the angle between the absorption axis of the rubbing axis of the liquid crystal alignment film of the polarizing film is substantially 15 °. 6. A step of forming a first liquid crystal alignment film having a rubbing axis whose angle to the longitudinal direction of the transparent support is substantially −15 ° above the elongated transparent support. ,
A layer containing a discotic liquid crystalline compound is formed on the first liquid crystal alignment film, and the discotic liquid crystalline compound is vertically aligned in a direction in which an optical axis is substantially perpendicular to the rubbing axis, The step of forming the first optically anisotropic layer having a phase difference of substantially π at a measurement wavelength of 550 nm and the angle between the transparent support and the longitudinal direction of the transparent support are substantially 15 A step of forming a second liquid crystal alignment film having a rubbing axis of 0 °, a layer containing a discotic liquid crystal compound is formed on the second liquid crystal alignment film, and the discotic liquid crystal compound is added to the layer. A second optical anisotropy in which the second liquid crystal alignment film is vertically aligned at an azimuth angle in which the optical axis is substantially parallel to the rubbing axis, and the phase difference at a measurement wavelength of 550 nm is substantially π / 2. A step of forming a layer, and the transparent support A step of forming a polarizing film having a polarizing axis in a direction substantially perpendicular to the longitudinal direction of the transparent support by making the longitudinal direction of the transparent support substantially coincide with the absorption axis below. Manufacturing method of circularly polarizing plate.