JP3399705B2 - Compensation film for liquid crystal display element and liquid crystal display device incorporating the compensation film - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compensating film capable of simultaneously performing color compensation and viewing angle compensation for a liquid crystal display utilizing hybrid nematic alignment.

[0002]

2. Description of the Related Art A liquid crystal display (HAN = Hybrid Align) using a hybrid nematic alignment.
In ed Nematic), as shown in FIG. 1, nematic liquid crystal molecules are aligned substantially parallel to the substrate near one substrate interface, and molecules are aligned substantially perpendicular to the substrate near the opposite substrate interface. . This method is characterized in that it can be driven at a low voltage and that gradation display is easy (S. Matsumoto, M. Kawamoto a.
nd K. Mizuya: J.M. Appl. Phy
s. 47, 3842 (1976)), which has hardly been put into practical use until now. One of the major problems with this method is that the viewing angle is narrow due to the asymmetry due to the different alignment patterns above and below the liquid crystal cell. Since a liquid crystal display uses a material having optical anisotropy such as a polarizing plate or a liquid crystal material, the problem of the viewing angle cannot be basically avoided, but the viewing angle is particularly narrow in this method. When viewed obliquely from the zx plane direction in FIG. 1, the apparent retardation value changes according to the tilt angle. Further, when viewed obliquely from the yz-plane direction, in addition to the change in retardation value, the effect of optical rotation dispersion due to the change in orientation along the z-axis direction also occurs.

In order to compensate the viewing angle of the display of this system, it is considered effective to have a refractive index structure opposite to that of the liquid crystal cell. Furthermore, the compensator must have a color compensation effect. That is, when the liquid crystal cell is viewed from the front, a retardation having a slow axis in the x direction of FIG. 1 occurs more or less. Therefore, in order to obtain a display with a high contrast ratio, it is necessary to perform color compensation by canceling out the in-plane retardation of the liquid crystal cell during black display. In principle, it is possible to use a conventional uniaxially stretched film or the like if only color compensation is performed. However, an optical film capable of performing viewing angle compensation or an optical film capable of simultaneously performing color compensation and viewing angle compensation has not been obtained.

[0004]

SUMMARY OF THE INVENTION The present invention is intended to solve the above-mentioned problems. As a compensator for a liquid crystal display having a driving liquid crystal cell with a hybrid nematic alignment, it can perform color compensation and expand the viewing angle which has never been seen before. The present invention provides a compensation film capable of achieving the above, specifically, a compensation film formed by fixing a hybrid alignment form of discotic liquid crystal. Further, the present invention provides a liquid crystal display device incorporating the compensation film.

[0005]

Means for Solving the Problems That is, the first aspect of the present invention
Is used for a liquid crystal display device including a pair of polarizing plates and a driving liquid crystal cell having a hybrid nematic alignment structure,
A compensating film comprising a liquid crystalline optical film, wherein the film is a film in which an alignment form of discotic liquid crystal formed from a discotic liquid crystal material is fixed, and the alignment form is a director of the discotic liquid crystal. The present invention relates to a compensating film for a liquid crystal display element, which has a hybrid orientation in which an angle formed with a plane of the film is different between an upper surface and a lower surface of the film.

A second aspect of the present invention is a compensating film comprising a liquid crystal optical film used for a driving liquid crystal cell having a hybrid nematic alignment structure and a reflective liquid crystal display device having a single polarizing plate. The film is a film in which the orientation form of discotic liquid crystal formed from a discotic liquid crystalline material is fixed, and the orientation form forms an angle between the director of the discotic liquid crystal and the film plane. The present invention relates to a compensating film for a liquid crystal display element, which has different hybrid orientations on an upper surface and a lower surface.

In a third aspect of the present invention, the hybrid orientation is such that the director of the discotic liquid crystal makes an angle of 60 degrees or more and 90 degrees or less with the plane of the film on one side of the film, and The first or second compensating film for a liquid crystal display element is characterized in that it has a hybrid orientation that forms an angle of 0 degree or more and 50 degrees or less in the plane.

A fourth aspect of the present invention is the first or third aspect.
At least one compensating film for a liquid crystal display element is incorporated, and a liquid crystal display device comprising a driving liquid crystal cell having a hybrid nematic alignment structure and a pair of polarizing plates whose polarization directions are orthogonal to each other.

A fifth aspect of the present invention is characterized in that at least one compensation film for the second or third liquid crystal display device is incorporated, and a driving liquid crystal cell having a hybrid nematic alignment structure and one The present invention relates to a liquid crystal display device including a polarizing plate.

The wood invention will be described in detail below. The target of the compensation of the present invention is a liquid crystal cell in which nematic liquid crystal molecules enclosed between two substrates constituting a driving liquid crystal cell have a structure in which the orientation of the liquid crystal molecules at the substrate interface is different from each other. It is a liquid crystal display. An example of the liquid crystal display as described above is a liquid crystal display utilizing hybrid nematic alignment. The liquid crystal cell for driving the display is
Nematic liquid crystal molecules are aligned substantially parallel to the substrate near the substrate interface on one side, and the molecules are aligned substantially perpendicular to the substrate surface near the interface on the opposite side.
Generally, the two substrates constituting the driving liquid crystal cell are subjected to different alignment treatments. Usually, the substrate on one side is a rubbing polyimide alignment film, a rubbing polyvinyl alcohol alignment film, or the like in order to align the nematic liquid crystal molecules enclosed in the driving liquid crystal cell in a plane and align the director in one direction. An organic thin film that has been subjected to a rubbing treatment is provided. On the other substrate, a silane coupling agent, a metal complex such as chromium, or a long-chain alkyl group is formed in order to form the nematic liquid crystal molecules enclosed in the driving liquid crystal cell in a vertical alignment with respect to the substrate. A substrate in which the substrate is subjected to orientation treatment with a surfactant or the like is used.

The liquid crystal to be sandwiched between the two cell substrates is a rod-shaped (calamic) nematic liquid crystal.
The dielectric anisotropy (Δε) may be positive or negative.
When the dielectric anisotropy is positive (Δε> 0), by applying a voltage,
The liquid crystal molecules change their orientation so that the director becomes more perpendicular to the substrate (Fig. 1 (a) → (b)), and when the dielectric anisotropy is negative (Δε <0), the director moves more toward the substrate. It changes to be parallel (Fig. 1 (a) → (c)). The present invention can compensate for either of them. There are two kinds of modes depending on whether the low voltage state (a) is black display (normally black mode) or the state where a higher voltage is applied is black display (normally white mode). The compensation film of the present invention can compensate for both.

As described above, four kinds of display methods as shown in Table 1 are possible depending on the difference in the dielectric anisotropy of the liquid crystal and the mode, and the compensation film of the present invention is color-compensated for any of them. In addition, the viewing angle can be compensated. The cell driving method may be simple matrix driving using a dielectric thin film such as ITO for the electrodes, or TFT (Thin) on one side of the substrate.
Film Transistor electrode and MIM (M
etal Insulator Metal, also known as TF
Active matrix driving using a D = Thin Film Diode electrode may be used, and the compensation film of the present invention is applicable to any method. In addition, since rubbing operation is not always necessary for a substrate that has been subjected to vertical alignment treatment, when performing active matrix driving, if a substrate to be hydrophobized is selected as the active matrix electrode substrate, it will be destroyed by rubbing operation of expensive electrodes. This is preferable from the viewpoint of cost because there is no fear of

[0013]

[Table 1] ^* See Figure 1

Next, the compensation film of the present invention in which the hybrid orientation is fixed will be described. In general, discotic liquid crystals are liquid crystals that are expressed by molecules having a mesogen in the form of a highly flat disc. The characteristic of the discotic liquid crystal is that the refractive index in the microscopic region in the liquid crystal layer has negative uniaxiality. As shown in FIG. 2, the refractive index in a plane is equal (no), the direction perpendicular to the plane is the optical axis (hereinafter referred to as the director), and the refractive index in the director direction is ne. And n
o> ne. How the directors in such a minute region are arranged in the liquid crystal layer determines the refractive index characteristic and thus the optical characteristic of the resulting structure. The refractive index structure of the nematic liquid crystal used in the liquid crystal cell is in contrast to the discotic liquid crystal as shown in FIG. 2B, and the positive uniaxial refractive index structure is present in the extremely small area. I have

Discotic liquid crystals typically have the same orientation of directors across the liquid crystal layer:
When the discotic liquid crystal has a negative uniaxial structure and the discotic liquid crystal is uniformly aligned by the conventional method, normally, as shown in FIG.
The structure of (b) is adopted. 3A is called homeotropic alignment because the director is in the normal line of the substrate. (B) is a tilt orientation in which the director is tilted by a certain angle from the substrate normal.

The structure of the compensation film of the present invention is completely different from the above-described homeotropic alignment, tilt alignment, and negative uniaxial structure based on the alignment form. That is, the director forms a hybrid orientation (FIG. 3 (c)) that is different between the upper surface and the lower surface of the film, and preferably gradually changes in the film thickness direction, and there is no optical axis, and uniaxiality is lost. It is a thing. In a rod-shaped nematic liquid crystal, such a director in which the director continuously changes in the thickness direction is called a hybrid alignment (the liquid crystal cell to be compensated in the present invention has exactly this alignment structure). In the present invention, this orientation form is also called hybrid orientation.

Generally, in order to perform sufficient viewing angle compensation,
The refractive index anisotropy of the driving liquid crystal cell to be compensated must be canceled. In the driving liquid crystal cell to be compensated, the rod-shaped liquid crystal having a positive uniaxial feature has its director continuously changed in the film thickness direction, so the compensation film has a negative uniaxial feature. As shown in Fig. 3, the director was continuously changed in the film thickness direction.
The structure of (c) is preferable. Since there is no director change in the film thickness direction in FIGS. 3A and 3B, it is difficult to perform complete viewing angle compensation. For the driving liquid crystal cell of the hybrid nematic alignment, it is necessary to cancel the in-plane retardation and perform color compensation as described above. Since the discotic liquid crystal forms a hybrid alignment in the compensation film of the present invention, it also has an in-plane retardation, and can perform viewing angle compensation and color compensation at the same time.

In the present invention, the angle range in the film thickness direction of the hybrid oriented film is defined by the absolute value of the minimum angle between the director of the film and the plane of the film, that is, the normal of the director of the film and the plane of the film. When the angle that is not on the obtuse angle side (the angle within the range of 0 degrees to 90 degrees) is set to a degree, [90 degrees-a
The angle obtained by [degree] is usually 60 degrees or more and 90 degrees or less on either the upper surface or the lower surface of the film, and is usually 0 degrees or more and 50 degrees or less on the opposite surface. More preferably, the absolute value of one angle is 70 degrees or more and 90 degrees or less, and the absolute value of the other angle is 0.
It is not less than 30 degrees and not more than 30 degrees.

In the present invention, the angle range in the film thickness direction of the hybrid orientation film is defined by the absolute value of the minimum angle formed by the director of the film and the plane of the film, that is, the normal of the director of the film and the plane of the film. When the angle which is not on the obtuse angle side (the angle in the range of 0 degree to 90 degrees) is set to a degree, [90 degree-a
Degree] is usually 60 degrees or more and 90 degrees or less on one of the upper surface and the lower surface of the film, and 0 degrees or more and 50 degrees or less on the opposite surface.
It is below the degree. More preferably, the absolute value of one angle is 8
0 degrees or more and 90 degrees or less, and the absolute value of the other angle is 0 degrees or more and 3
It is 0 degrees or less.

In the compensation film of the present invention, the directors are oriented in different directions in the thickness direction because they form a hybrid orientation, and when viewed as a structure called a film, the optical axis no longer exists and the uniaxial property is present. Is lost. When light passes through such an alignment form of the liquid crystal, it is possible to observe a complicated birefringence behavior that has not been obtained conventionally.

Next, the discotic liquid crystalline material used in the present invention will be described. The material comprises a discotic liquid crystal compound alone or a composition containing at least one liquid crystal compound. The discotic liquid crystal is C.I. According to Destrade et al., The ND phase (discotic nemati
c phase), Dho phase (hexagonal o
rdered column phase), Dh
d phase (hexagonal disordered c
optical phase), Drd phase (recta)
ngular disordered columna
r phase), Dob phase (oblique col)
umnar phase) (C. Destrade et al. Mol. Cry
st. Liq. Cryst. 106, 121 (198
4)). In the present invention, the alignment order of these molecules is not particularly limited, but from the viewpoint of ease of alignment, a material having at least an ND phase having the lowest alignment order is preferable, and it is particularly preferable that only the ND phase is the only liquid crystal phase. It has as.

The discotic liquid crystalline material used in the present invention is preferably a material which does not cause a transition from a liquid crystal phase to a crystalline phase at the time of immobilization in order to immobilize it without impairing the alignment form in the liquid crystal state. Further, it is preferable that the oriented form be maintained under the conditions of use when the film is formed, and that the film can be handled like a solid. Furthermore, the state of being immobilized in the present invention is the most typical and preferable mode in which the liquid crystal structure is frozen in an amorphous glass state, but is not limited thereto.
The use conditions of the compensation film of the present invention, specifically 0 ° C to 50 ° C, and -30 ° C to 7 ° C under more severe conditions.
In the temperature range of 0 ° C, the film has no fluidity,
It also refers to a state in which the fixed alignment form can be kept stable without causing a change in the alignment form due to an external field or an external force. From the above, as the discotic liquid crystalline material used in the present invention,
Those having any of the following properties are preferable.

It has only a glass phase in a lower temperature range than a liquid crystal state and has no crystal phase. When the temperature is lowered from the liquid crystal state, it is fixed in the glass state. It has a crystalline phase in the lower temperature range than the liquid crystal state and a glass phase in the lower temperature range than the crystalline phase. When the temperature is lowered from the liquid crystal state, the crystalline phase does not appear (the crystalline phase is overcooled). If the temperature is lower than that of the liquid crystal state, it is fixed in the glass state.

Although it has a crystal phase in a lower temperature range than the liquid crystal state, it does not show a clear glass transition in a lower temperature range, and a crystal phase does not appear when the temperature is lowered from the liquid crystal state (crystal phase If it is supercooled, or if it is monotropic that causes crystallization only when the temperature rises). In this case, at a temperature lower than the melting point (observed when it is fixed and then heated to a high temperature again), it can be regarded as a practically solid material in which the fluidity of the molecule is extremely limited. In the temperature range lower than the liquid crystal state, neither a clear transition to a crystal nor a transition to a glass state is observed in the temperature rising and lowering processes, but when the alignment morphology in the liquid crystal state is fixed, it is within the operating temperature range of this film. There is no liquidity at all,
Moreover, the orientation form does not change even when an external force such as a slip or an external field is applied.

Among the above, the more preferable case is any one of and, and the most preferable case is the one having the property of. In any of the cases 1 and 2, it can be practically used without any problem, but it is necessary to carefully confirm that there is no possibility of disorder of orientation under the conditions of use of the film. Specifically, in the temperature range of 0 ° C. to 50 ° C., there is no particular problem as long as the alignment form is not disturbed by, for example, forcibly adding a gap. When the orientation form is disturbed due to misalignment or the like, the original optical performance is lost, and it is difficult to restore the orientation form to the original orientation form by any treatment thereafter, which is a serious problem in actual use.

It is desirable that the discotic liquid crystalline material used in the present invention has any of the above-mentioned properties and, at the same time, exhibits good domain cohesion due to uniform defect-free alignment. If the domains have poor cohesion, the resulting structure becomes a polydomain, alignment defects occur at the boundaries between the domains, and light is scattered. In addition, the transmittance of the film is reduced, which is not desirable. Next, a discotic liquid crystal compound that can be used as the liquid crystal material will be described. The specific structure of the compound is mainly composed of a disc-shaped central portion (discogen) essential for developing a discotic liquid crystal phase, and a substituent necessary for stabilizing the liquid crystal phase. . As the substituent, a monofunctional one is preferably used, but a compound obtained by partially linking the discogens with each other to obtain an oligomer or a polymer by using a bifunctional one is also a material of the present invention. Can be preferably used as The molecular structures of the discotic liquid crystal compounds that can be used in the present invention are specifically shown above.

[0027]

[Chemical 1] R ₁ , R ₂ and R ₃ are the same or different monofunctional or difunctional substituents selected from the following groups. As the monofunctional substituent,

[0028]

[Chemical 2] However, C _n H _{2n + 1} is a linear or branched alkyl group, and n is an integer of 1 or more and 18 or less, more preferably 3 or more and 14 or less. As the bifunctional substituent,

[0029]

[Chemical 3] However, C _m H _2m is a linear or branched alkylene chain, and m is an integer of 2 or more and 16 or less, more preferably 4 or more and 12 or less. To illustrate the specific structure,

[0030]

[Chemical 4] However, p, q, and r are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less.

[0031]

[Chemical 5] However, p, q, and r are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less.

[0032]

[Chemical 6] However, p, q, and r are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less.

[0033]

[Chemical 7] However, p, q, and r are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less.

[0034]

[Chemical 8] However, p, q, and r are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less.

[0035]

[Chemical 9] Polymer represented by. Q is

[0036]

[Chemical 10] Here, n is an integer of 1 or more and 18 or less, more preferably 3 or more and 14 or less. m is an integer of 2 or more and 16 or less, more preferably an integer of 4 or more and 12 or less. Average molecular weight is 4,000
The range is 0 or more and 100,000 or less.

[0037]

[Chemical 11] R ₁ , R ₂ and R ₃ are the same or different monofunctional or difunctional substituents selected from the following groups. As the monofunctional substituent,

[0038]

[Chemical 12] However, C _n H _{2n + 1} is a linear or branched alkyl group, and n is an integer of 1 or more and 18 or less, more preferably 3 or more and 14 or less. As the bifunctional substituent,

[0039]

[Chemical 13] However, C _m H _2m is a linear or branched alkylene chain, and m is an integer of 2 or more and 16 or less, more preferably 4 or more and 12 or less. To illustrate the specific structure,

[0040]

[Chemical 14] However, p, q, and r are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less.

[0041]

[Chemical 15] However, p, q, and r are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less.

[0042]

[Chemical 16] However, p, q, and r are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less.

[0043]

[Chemical 17] However, p, q, and r are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less.

[0044]

[Chemical 18] However, p, q, and r are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less.

[0045]

[Chemical 19] However, p, q, and r are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less.

[0046]

[Chemical 20] Polymer represented by. Average molecular weight is 4,000 or more 10
Range of 10,000 or less. Q is

[0047]

[Chemical 21] However, n is an integer of 1 or more and 18 or less, more preferably 3
An integer not less than 14 and not more than 14. m is an integer of 2 or more and 16 or less, more preferably an integer of 4 or more and 12 or less.

[0048]

[Chemical formula 22] R ₁ , R ₂ , R ₃ and R ₄ are the same or different monofunctional or difunctional substituents selected from the following groups. As the monofunctional substituent,

[0049]

[Chemical formula 23] However, C _n H _{2n + 1} is a linear or branched alkyl group, and n is an integer of 1 or more and 18 or less, more preferably 3 or more and 14 or less. As the bifunctional substituent,

[0050]

[Chemical formula 24] However, C _m and H _2m are linear or branched alkylene chains, and m is an integer of 2 or more and 16 or less, more preferably 4 or more and 12 or less. To illustrate the specific structure,

[0051]

[Chemical 25] However, p, q, r and s are integers from 1 to 18 inclusive,
More preferably, it is an integer of 3 or more and 14 or less.

[0052]

[Chemical formula 26] However, p, q, r and s are integers from 1 to 18 inclusive,
More preferably, it is an integer of 3 or more and 14 or less.

[0053]

[Chemical 27] However, p, q, r and s are integers from 1 to 18 inclusive,
More preferably, it is an integer of 3 or more and 14 or less.

[0054]

[Chemical 28] However, p, q, r and s are integers from 1 to 18 inclusive,
More preferably, it is an integer of 3 or more and 14 or less.

[0055]

[Chemical 29] However, p, q, r and s are integers from 1 to 18 inclusive,
More preferably, it is an integer of 3 or more and 14 or less.

[0056]

[Chemical 30] However, p, q, r and s are integers from 1 to 18 inclusive,
More preferably, it is an integer of 3 or more and 14 or less.

[0057]

[Chemical 31] However, p, q, r and s are integers from 1 to 18 inclusive,
More preferably, it is an integer of 3 or more and 14 or less.

[0058]

[Chemical 32] R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , and R ₆ are the same or different monofunctional or difunctional substituents selected from the following groups. As the monofunctional substituent,

[0059]

[Chemical 33] However, C _n H _{2n + 1} is a linear or branched alkyl group, n is an integer of 1 or more and 18 or less, more preferably 3 or more and 14 or less, and k is 1, 2, or 3. As the bifunctional substituent,

[0060]

[Chemical 34] However, C _m H _2m is a linear or branched alkylene chain, and m is an integer of 2 or more and 16 or less, more preferably 4 or more and 12 or less. As a concrete example,

[0061]

[Chemical 35] However, p, q, r, s, t, and u are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less.

[0062]

[Chemical 36] However, p, q, r, s, t, and u are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less.

[0063]

[Chemical 37] However, p, q, r, s, t, and u are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less.

[0064]

[Chemical 38] However, p, q, r, s, t, and u are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less.

[0065]

[Chemical Formula 39] However, p, q, r, s, t, and u are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less.

[0066]

[Chemical 40] However, p, q, r, s, t, and u are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less.

[0067]

[Chemical 41] However, p, q, r, s, t, and u are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less.

[0068]

[Chemical 42] The composition represented by: The numbers beside the parentheses indicate the molar composition ratio. 0 ≦ x ≦ 6, 0 ≦ y ≦ 6. p, q, and r are integers of 1 or more and 18 or less, more preferably 3
An integer not less than 14 and not more than 14.

[0069]

[Chemical 43] The composition represented by: The numbers beside the parentheses indicate the molar composition ratio. 0 ≦ x ≦ 6. p and q are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less.

[0070]

[Chemical 44] The composition represented by: The numbers beside the parentheses indicate the molar composition ratio. 0 ≦ x ≦ 6, 0 ≦ y ≦ 6. p, q, and r are integers of 1 or more and 18 or less, more preferably 3
An integer not less than 14 and not more than 14.

[0071]

[Chemical formula 45] However, p, q, r, s, t, u, v and w are integers of 3 or more and 18 or less, more preferably 5 or more and 14 or less. k is 1, 2 or 3.

[0072]

[Chemical formula 46] However, p, q, r, s, t, u, v, w, a and b
Is an integer of 1 or more and 18 or less, more preferably 3 or more and 14
The following integer. Q is

[0073]

[Chemical 47] However, m is an integer of 2 or more and 16 or less. More preferably Q
Is

[0074]

[Chemical 48] However, m is an integer of 2 or more and 18 or less, more preferably 4 or more and 12 or less.

[0075]

[Chemical 49] However, p, q, r, s, t, u, v, w, a and b
Is an integer of 1 or more and 18 or less, more preferably 3 or more and 14
The following integer. Q is

[0076]

[Chemical 50] However, m is an integer of 2 or more and 16 or less. More preferably Q
Is

[0077]

[Chemical 51] However, m is an integer of 2 or more and 16 or less, more preferably 4 or more and 12 or less.

[0078]

[Chemical 52] However, p, q, r, s, t, u, v, w, a and b
Is an integer of 1 or more and 18 or less, more preferably 3 or more and 14
The following integer. Q is

[0079]

[Chemical 53] However, m is an integer of 2 or more and 16 or less. More preferably Q
Is

[0080]

[Chemical 54] However, m is an integer of 2 or more and 16 or less, more preferably 4 or more and 12 or less.

[0081]

[Chemical 55] However, p, q, r, s, t, u, v, w, a, b,
c, d, e and f are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less. Q is

[0082]

[Chemical 56] However, m is an integer of 2 or more and 16 or less. More preferably Q
Is

[0083]

[Chemical 57] However, m is an integer of 2 or more and 16 or less, more preferably 4 or more and 12 or less.

[0084]

[Chemical 58] However, p, q, r, s, t, u, v, w, a, b,
c, d, e and f are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less. Q is

[0085]

[Chemical 59] However, m is an integer of 2 or more and 16 or less. More preferably Q
Is

[0086]

[Chemical 60] However, m is an integer of 2 or more and 16 or less, more preferably 4 or more and 12 or less.

[0087]

[Chemical formula 61] Polymer represented by. However, p, q, r, s, t,
u, v, and w are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less. Average molecular weight is 5,000 to 1
Range of 0,000. Q is

[0088]

[Chemical formula 62] However, m is an integer of 2 or more and 16 or less. More preferably Q
Is

[0089]

[Chemical formula 63] However, m is an integer of 2 or more and 16 or less, more preferably 4 or more and 12 or less.

[0090]

[Chemical 64] R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , and R ₆ are the same or different monofunctional or difunctional substituents selected from the following groups. As the monofunctional substituent,

[0091]

[Chemical 65] However, C _n H _{2n + 1} is a linear or branched alkyl group, n is an integer of 1 or more and 18 or less, more preferably 3 or more and 14 or less, and k is 1, 2, or 3. As the bifunctional substituent,

[0092]

[Chemical formula 66] However, C _m H _2m is a linear or branched alkylene chain, and m is an integer of 2 or more and 16 or less, more preferably 4 or more and 12 or less. As a concrete example,

[0093]

[Chemical formula 67] However, p, q, r, s, t, and u are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less.

[0094]

[Chemical 68] However, p, q, r, s, t, and u are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less.

[0095]

[Chemical 69] However, p, q, r, s, t, and u are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less.

[0096]

[Chemical 70] However, p, q, r, s, t, and u are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less.

[0097]

[Chemical 71] However, p, q, r, s, t, and u are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less.

[0098]

[Chemical 72] However, p, q, r, s, t, and u are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less.

[0099]

[Chemical formula 73] However, p, q, r, s, t, and u are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less.

[0100]

[Chemical 74] The composition represented by: The numbers beside the parentheses indicate the molar composition ratio. 0 ≦ x ≦ 6, 0 ≦ y ≦ 6. p, q, and r are integers of 1 or more and 18 or less, more preferably 3
An integer not less than 14 and not more than 14.

[0101]

[Chemical 75] The composition represented by: The numbers beside the parentheses indicate the molar composition ratio. 0 ≦ x ≦ 6. p and q are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less.

[0102]

[Chemical 76] The composition represented by: The numbers beside the parentheses indicate the molar composition ratio. 0 ≦ x ≦ 6, 0 ≦ y ≦ 6. p, q, and r are integers of 1 or more and 18 or less, more preferably 3
An integer not less than 14 and not more than 14.

[0103]

[Chemical 77] However, p, q, r, s, t, u, v, w, a and b
Is an integer of 1 or more and 18 or less, more preferably 3 or more and 14
The following integer. Q is

[0104]

[Chemical 78] However, m is an integer of 2 or more and 16 or less. More preferably Q
Is

[0105]

[Chemical 79] However, m is an integer of 2 or more and 16 or less, more preferably 4 or more and 12 or less.

[0106]

[Chemical 80] Polymer represented by. However, p, q, r, s, t,
u, v, and w are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less. Average molecular weight is 5,000 to 1
Range of 0,000. Q is

[0107]

[Chemical 81] However, m is an integer of 2 or more and 16 or less. More preferably Q
Is

[0108]

[Chemical formula 82] However, m is an integer of 2 or more and 16 or less, more preferably 4 or more and 12 or less.

[0109]

[Chemical 83] R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , and R ₆ are the same or different monofunctional or difunctional substituents selected from the following groups. As the monofunctional substituent,

[0110]

[Chemical 84] However, C _n H _{2n + 1} is a linear or branched alkyl group, n is an integer of 1 or more and 18 or less, more preferably 3 or more and 14 or less, and k is 1, 2, or 3. As the bifunctional substituent,

[0111]

[Chemical 85] However, C _m and H _2m are linear or branched alkylene chains, and m is an integer of 2 or more and 16 or less, more preferably 4 or more and 12 or less. To illustrate the specific structure,

[0112]

[Chemical 86] However, p, q, r, s, t, and u are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less.

[0113]

[Chemical 87] However, p, q, r, s, t, and u are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less.

[0114]

[Chemical 88] However, p, q, r, s, t, and u are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less.

[0115]

[Chemical 89] However, p, q, r, s, t, and u are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less.

[0116]

[Chemical 90] However, p, q, r, s, t, and u are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less.

[0117]

[Chemical Formula 91] However, p, q, r, s, t, and u are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less.

[0118]

[Chemical Formula 92] However, p, q, r, s, t, and u are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less.

[0119]

[Chemical formula 93] The composition represented by: The numbers beside the parentheses indicate the molar composition ratio. 0 ≦ x ≦ 6, 0 ≦ y ≦ 6. p, q, and r are integers of 1 or more and 18 or less, more preferably 3
An integer not less than 14 and not more than 14.

[0120]

[Chemical 94] The composition represented by: The numbers beside the parentheses indicate the molar composition ratio. 0 ≦ x ≦ 6. p and q are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less.

[0121]

[Chemical 95] The composition represented by: The numbers beside the parentheses indicate the molar composition ratio. 0 ≦ x ≦ 6, 0 ≦ y ≦ 6. p, q, and r are integers of 1 or more and 18 or less, more preferably 3
An integer not less than 14 and not more than 14.

[0122]

[Chemical 96] However, p, q, r, s, t, and u are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less, and k is 1, 2, or 3.

[0123]

[Chemical 97] However, p, q, r, s, t, u, v, w, a and b
Is an integer of 1 or more and 18 or less, more preferably 3 or more and 14
The following integer. Q is

[0124]

[Chemical 98] However, m is an integer of 2 or more and 16 or less. More preferably Q
Is

[0125]

[Chemical 99] However, m is an integer of 2 or more and 16 or less, more preferably 4 or more and 12 or less.

[0126]

[Chemical 100] However, p, q, r, s, t, u, v, w, a and b
Is an integer of 1 or more and 18 or less, more preferably 3 or more and 14
The following integer. Q is

[0127]

[Chemical 101] However, m is an integer of 2 or more and 16 or less. More preferably Q
Is

[0128]

[Chemical 102] However, m is an integer of 2 or more and 16 or less, more preferably 4 or more and 12 or less.

[0129]

[Chemical 103] However, p, q, r, s, t, u, v, w, a and b
Is an integer of 1 or more and 18 or less, more preferably 3 or more and 14
The following integer. Q is

[0130]

[Chemical 104] However, m is an integer of 2 or more and 16 or less. More preferably Q
Is

[0131]

[Chemical 105] However, m is an integer of 2 or more and 16 or less, more preferably 4 or more and 12 or less.

[0132]

[Chemical formula 106] However, p, q, r, s, t, u, v, w, a, b,
c, d, e and f are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less. Q is

[0133]

[Chemical formula 107] However, m is an integer of 2 or more and 16 or less. More preferably Q
Is

[0134]

[Chemical 108] However, m is an integer of 2 or more and 16 or less, more preferably 4 or more and 12 or less.

[0135]

[Chemical 109] Polymer represented by. However, p, q, r, s, t,
u, v, and w are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less. Average molecular weight is 5,000 to 1
Range of 0,000. Q is

[0136]

[Chemical 110] However, m is an integer of 2 or more and 16 or less. More preferably Q
Is

[0137]

[Chemical 111] However, m is an integer of 2 or more and 16 or less, more preferably 4 or more and 12 or less.

[0138]

[Chemical 112] R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , and R ₆ are the same or different monofunctional or difunctional substituents selected from the following groups. As the monofunctional substituent,

[0139]

[Chemical 113] However, C _n H _{2n + 1} is a linear or branched alkyl group, n is an integer of 1 or more and 18 or less, more preferably 3 or more and 14 or less, and k is 1, 2, or 3. As the bifunctional substituent,

[0140]

[Chemical 114] However, C _m H _2m is a linear or branched alkylene chain, and m is an integer of 2 or more and 16 or less, more preferably 4 or more and 12 or less. To illustrate the specific structure,

[0141]

[Chemical 115] However, p, q, r, s, t, and u are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less.

[0142]

[Chemical formula 116] However, p, q, r, s, t, and u are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less.

[0143]

[Chemical 117] However, p, q, r, s, t, and u are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less.

[0144]

[Chemical 118] However, p, q, r, s, t, and u are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less.

[0145]

[Chemical formula 119] However, p, q, r, s, t, and u are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less.

[0146]

[Chemical 120] However, p, q, r, s, t, and u are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less.

[0147]

[Chemical 121] However, p, q, r, s, t, and u are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less.

[0148]

[Chemical formula 122] The composition represented by: The numbers beside the parentheses indicate the molar composition ratio. 0 ≦ x ≦ 6, 0 ≦ y ≦ 6. p, q, and r are integers of 1 or more and 18 or less, more preferably 3
An integer not less than 14 and not more than 14.

[0149]

[Chemical 123] The composition represented by: The numbers beside the parentheses indicate the molar composition ratio. 0 ≦ x ≦ 6. p and q are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less.

[0150]

[Chemical formula 124] The composition represented by: The numbers beside the parentheses indicate the molar composition ratio. 0 ≦ x ≦ 6, 0 ≦ y ≦ 6. p, q, and r are integers of 1 or more and 18 or less, more preferably 3
An integer not less than 14 and not more than 14.

[0151]

[Chemical 125] However, p, q, r, s, t, and u are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less, and k is 1, 2, or 3.

[0152]

[Chemical formula 126] However, p, q, r, s, t, u, v, w, a and b
Is an integer of 1 or more and 18 or less, more preferably 3 or more and 14
The following integer. Q is

[0153]

[Chemical 127] However, m is an integer of 2 or more and 16 or less. More preferably Q
Is

[0154]

[Chemical 128] However, m is an integer of 2 or more and 16 or less, more preferably 4 or more and 12 or less.

[0155]

[Chemical formula 129] However, p, q, r, s, t, u, v, w, a and b
Is an integer of 1 or more and 18 or less, more preferably 3 or more and 14
The following integer. Q is

[0156]

[Chemical 130] However, m is an integer of 2 or more and 16 or less. More preferably Q
Is

[0158]

[Chemical 131] However, m is an integer of 2 or more and 16 or less, more preferably 4 or more and 12 or less.

[0158]

[Chemical 132] However, p, q, r, s, t, u, v, w, a and b
Is an integer of 1 or more and 18 or less, more preferably 3 or more and 14
The following integer. Q is

[0159]

[Chemical 133] However, m is an integer of 2 or more and 16 or less. More preferably Q
Is

[0160]

[Chemical 134] However, m is an integer of 2 or more and 16 or less, more preferably 4 or more and 12 or less.

[0161]

[Chemical 135] However, p, q, r, s, t, u, v, w, a, b,
c, d, e and f are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less. Q is

[0162]

[Chemical 136] However, m is an integer of 2 or more and 16 or less. More preferably Q
Is

[0163]

[Chemical 137] However, m is an integer of 2 or more and 16 or less, more preferably 4 or more and 12 or less.

[0164]

[Chemical 138] Polymer represented by. However, p, q, r, s, t,
u, v and w are integers of 1 or more and 18 or less, more preferably 3 or more and 14 or less. The average molecular weight is in the range of 5,000 to 100,000. Q is

[0165]

[Chemical 139] However, m is an integer of 2 or more and 16 or less. More preferably Q
Is

[0166]

[Chemical 140] However, m is an integer of 2 or more and 16 or less, more preferably 4 or more and 12 or less.

Further, polyacrylate, polymethacrylate having a side chain of the compound having the above structural formula,
Polymers such as polysiloxane are also preferably used. In particular,

[0168]

[Chemical 141] However, n is an integer of 1 or more and 18 or less, more preferably 3
An integer not less than 14 and not more than 14.

[0169]

[Chemical 142] However, n is an integer of 1 or more and 18 or less, more preferably 3
An integer not less than 14 and not more than 14.

[0170]

[Chemical 143] However, n is an integer of 1 or more and 18 or less, more preferably 3
An integer not less than 14 and not more than 14.

[0171]

[Chemical 144] However, n is an integer of 1 or more and 18 or less, more preferably 3
An integer not less than 14 and not more than 14.

[0172]

[Chemical 145] However, n is an integer of 1 or more and 18 or less, more preferably 3
An integer not less than 14 and not more than 14.

[0173]

[Chemical 146] However, n is an integer of 1 or more and 18 or less, more preferably 3
An integer not less than 14 and not more than 14.

[0174]

[Chemical 147] However, n is an integer of 1 or more and 18 or less, more preferably 3
It is an integer of 14 or more and 14 or less, m is an integer of 2 or more and 16 or less, more preferably an integer of 4 or more and 12 or less.

[0175]

[Chemical 148] However, n is an integer of 1 or more and 18 or less, more preferably 3
It is an integer of 14 or more and 14 or less, m is an integer of 2 or more and 16 or less, more preferably an integer of 4 or more and 12 or less.

[0176]

[Chemical 149] However, n is an integer of 1 or more and 18 or less, more preferably 3
It is an integer of 14 or more and 14 or less, m is an integer of 2 or more and 16 or less, more preferably an integer of 4 or more and 12 or less.

[0177]

[Chemical 150] However, n is an integer of 1 or more and 18 or less, more preferably 3
An integer not less than 14 and not more than 14.

[0178]

[Chemical 151] However, n is an integer of 1 or more and 18 or less, more preferably 3
An integer not less than 14 and not more than 14.

[0179]

[Chemical 152] However, n is an integer of 1 or more and 18 or less, more preferably 3
An integer not less than 14 and not more than 14.

[0180]

[Chemical 153] However, n is an integer of 1 or more and 18 or less, more preferably 3
An integer not less than 14 and not more than 14.

[0181]

[Chemical 154] However, n is an integer of 1 or more and 18 or less, more preferably 3
An integer not less than 14 and not more than 14.

[0182]

[Chemical 155] However, n is an integer of 1 or more and 18 or less, more preferably 3
An integer not less than 14 and not more than 14.

[0183]

[Chemical 156] However, n is an integer of 1 or more and 18 or less, more preferably 3
It is an integer of 14 or more and 14 or less, m is an integer of 2 or more and 16 or less, more preferably an integer of 4 or more and 12 or less.

[0184]

[Chemical 157] However, n is an integer of 1 or more and 18 or less, more preferably 3
An integer not less than 14 and not more than 14.

[0185]

[Chemical 158] However, n is an integer of 1 or more and 18 or less, more preferably 3
It is an integer of 14 or more and 14 or less, m is an integer of 2 or more and 16 or less, more preferably an integer of 4 or more and 12 or less.

[0186]

[Chemical 159] The composition represented by: However, the numbers next to the parentheses indicate the molar composition ratio.

[0187]

[Chemical 160] An oligomer composition represented by: However, the numbers next to the parentheses indicate the molar composition ratio.

[0188]

[Chemical 161] The composition represented by: However, the numbers next to the parentheses indicate the molar composition ratio.

[0189]

[Chemical 162] The compound represented by.

[0190]

[Chemical formula 163] Polymer represented by. However, the numbers next to the parentheses indicate the molar composition ratio. Is mentioned. The average molecular weight of the polymer is in the range of 5,000 or more and 100,000 or less.

The structural formulas illustrated above are typical examples of discotic liquid crystal compounds, and the compounds used in the present invention are not limited to these and may have the above-mentioned properties. For example, a discotic liquid crystal compound having any structure can be used alone or as a composition.

The discotic liquid crystalline material used in the present invention uses a compound in which a plurality of substituents on the mesogen are not all the same in order to avoid the transition from the liquid crystal phase to the crystal phase. When the same compound is used, at least one compound different from the compound (a compound having a different mesogen and / or substituent)
It is preferable to use and as a composition.

The above-mentioned discotic liquid crystalline compound mainly contains a large number of ether bonds or ester bonds in the molecule, and a known reaction method can be used for forming these bonds. For example, the Williamson method of nucleophilic substitution reaction of an alkoxide ion with a halogen compound of a primary alkyl can be used for ether bond formation, and the acid chloride method, which is a reaction of acid chloride and alcohol, for ester bond formation. The deacetic acid reaction, which is a reaction between an acetylated alcohol and an acid, is not particularly limited. Further, since the compound used in the present invention does not need to control the reaction such as the selection of the substituent at the substituting site of the discogen-constituting compound, for example, although the concrete depiction of the structural formula is difficult, It is also possible to obtain a discotic liquid crystal compound by reacting a compound which is capable of forming a substituent over a large number of types in excess of the number of substitution sites possessed by the compound in one reaction system. In this case, it occurs that a certain kind of substituent is not bound in the molecule of a compound constituting one discogen, but is bound in the molecule of another compound. Become. In the present invention, since the transition from the liquid crystal phase to the crystal phase is not desirable, it is preferable in the present invention to use the above-mentioned various kinds of substituents, for example, to reduce the symmetry of the molecular structure. is there. When the discotic liquid crystalline material described above is used in the present invention, it is preferable to use the material substantially consisting of the discotic liquid crystalline compound. In order to obtain a compensation film in which a hybrid alignment and immobilization is uniformly performed using the discotic liquid crystalline material as described above, it is preferable in the present invention to perform the substrate and each step described below.

First, the substrate (hereinafter referred to as the alignment substrate) will be described. In order to obtain the hybrid alignment of the present invention, it is desirable to sandwich the discotic liquid crystal material layer at different interfaces at the upper and lower sides. When the discotic liquid crystal material layer is sandwiched at the same interface, the alignments at the upper and lower interfaces of the liquid crystalline layer are the same. Therefore, it becomes difficult to obtain the hybrid orientation of the present invention. As a specific embodiment, one alignment substrate and an air interface are used, and the lower interface of the discotic liquid crystal layer is in contact with the alignment substrate and the upper interface is in contact with air. The substrates having different upper and lower interfaces can be used, but it is preferable to use one oriented substrate and the air interface in the manufacturing process.

The oriented substrate that can be used for the present invention is
It is desirable that the substrate has anisotropy so that the tilt direction of the liquid crystal (projection of the director onto the alignment substrate) can be defined. If the alignment substrate cannot define the liquid crystal tilt direction at all, only a structure tilted in a disordered direction can be obtained (the vector in which the director is projected onto the substrate becomes disordered). As the oriented substrate that can be used in the present invention, specifically, those having the following in-plane anisotropy are desirable, polyimide, polyamideimide, polyamide, polyetherimide, polyetheretherketone, Polyether ketone, polyketone sulfide, polyether sulfone, polysulfone, polyphenylene sulfide, polyphenylene oxide, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyacetal, polycarbonate, polyarylate, acrylic resin, polyvinyl alcohol, polypropylene, cellulosic plastic Plastic film substrates such as epoxy resin, epoxy resin, phenol resin, etc. and uniaxially stretched film substrates, aluminum with slit-like grooves on the surface, iron Metal substrates such as copper, etched alkaline glass surface in a slit form,
Examples include glass substrates such as borosilicate glass and flint glass.

In the present invention, the above various substrates may be subjected to surface treatment such as hydrophilic treatment or hydrophobic treatment, or the plastic film substrate may be subjected to a rubbing treatment, or a rubbing plastic film substrate. It is also possible to use the above-mentioned various substrates having a plastic film, such as a rubbing polyimide film or a rubbing polyvinyl alcohol film, and the above-mentioned various substrates having an oblique vapor deposition film of silicon oxide. In the above-mentioned various alignment substrates, as the substrate suitable for forming the discotic liquid crystal according to the present invention in a hybrid alignment, a substrate having a rubbing polyimide film, a rubbing polyimide substrate, a rubbing polyetheretherketone substrate, a rubbing polyetherketone is used. Examples thereof include substrates, rubbing polyether sulfone substrates, rubbing polyphenylene sulfide substrates, rubbing polyethylene terephthalate substrates, rubbing polyethylene naphthalate substrates, rubbing polyarylate substrates, and cellulosic plastic substrates.

The compensating film of the present invention can be obtained by applying the above-mentioned discotic liquid crystal material on these alignment substrates, followed by a uniform alignment process and a fixing process. The application of the discotic liquid crystalline material can be performed using a discotic liquid crystalline material solution in which the material is dissolved in various solvents, or a state in which the material is melted. Solution coating, in which the solution in which the liquid crystalline material is dissolved is used for coating, is preferable. The solution application will be described.

The discotic liquid crystalline material is dissolved in a solvent to prepare a solution having a predetermined concentration. The solvent at this time depends on the kind of the liquid crystalline material, but is usually halogenated hydrocarbons such as chloroform, dichloromethane, carbon tetrachloride, dichloroethane, tetrachloroethane, tritrichloroethylene, tetrachloroethylene, chlorobenzene, orthodichlorobenzene, phenol, Phenols such as parachlorophenol, aromatic hydrocarbons such as benzene, toluene, xylene, methoxybenzene, and 1,2-dimethoxybenzene, acetone, ethyl acetate, t-butyl alcohol, glycerin, ethylene glycol, triethylene glycol, Ethylene glycol monomethyl ether, diethylene glycol dimethyl ether, ethyl cellosolve, butyl cellosolve, 2-pyrrolidone,
N-methyl-2-pyrrolidone, pyridine, triethylamine, dimethylformamide, dimethylacetamide,
Acetonitrile, butyronitrile, carbon disulfide and the like, mixed solvents thereof and the like are used.

The concentration of the solution depends on the solubility of the liquid crystalline material and the film thickness of the intended compensation film, but cannot be generally stated, but it is usually used in the range of 1 to 60% by weight, It is preferably in the range of 3 to 40% by weight. These discotic liquid crystalline material solutions are then coated on the alignment substrate. As a coating method, a spin coating method, a roll coating method, a printing method, a curtain coating method (die coating method), a dipping and pulling method and the like can be adopted.
After coating, the solvent is removed and a layer of liquid crystal material having a uniform film thickness is first formed on the substrate. The conditions for removing the solvent are not particularly limited as long as the solvent can be generally removed and the layer of the liquid crystalline material does not flow or flow down. Usually, the solvent is removed by air drying at room temperature, drying on a hot plate, drying in a drying oven, blowing hot air or hot air.

The purpose of this coating / drying step is to first uniformly form a layer of discotic liquid crystalline material on the substrate, and the liquid crystalline material layer has not yet formed a hybrid orientation. In the present invention, the following heat treatment is preferable for the hybrid orientation. The heat treatment is performed at or above the liquid crystal transition point of the discotic liquid crystalline material. That is, the liquid crystal material is aligned in the liquid crystal state or is brought into an isotropic liquid state at a temperature higher than the temperature range in which the liquid crystal phase is exhibited, and then the temperature is lowered to the temperature range in which the liquid crystal phase is exhibited. . Usually, the temperature of the heat treatment is performed in the range of 50 ° C to 300 ° C, particularly preferably in the range of 100 ° C to 250 ° C.

The time required for the liquid crystal to have a sufficient orientation cannot be generally determined because it depends on the discotic liquid crystal material, but it is usually 5 seconds to 2 hours, preferably 10 seconds. To 40 minutes, particularly preferably 20 seconds to 20 minutes. If the time is shorter than 5 seconds, the temperature of the liquid crystalline material layer may not reach the predetermined temperature and the orientation may be insufficient. If the time is longer than 2 hours, the productivity may be decreased, which is not preferable. Through the above steps, first, hybrid alignment can be formed in the liquid crystal state.

In the present invention, a magnetic field or an electric field may be used in order to align the discotic liquid crystalline material in the heat treatment step. However, when a magnetic field or an electric field is applied during heat treatment, a uniform field force acts on the liquid crystalline material layer during application, so the director of the liquid crystal tends to point in a certain direction, and the director of the film It becomes difficult to obtain the hybrid orientation of the present invention which changes in the thickness direction. A thermally stable hybrid orientation can be obtained by once removing a field force after forming a homeotropic orientation, a tilt orientation or another orientation other than the hybrid orientation, but there is no particular advantage in the process. The hybrid alignment in the liquid crystal state thus obtained is then cooled to fix the alignment form without impairing the alignment form to obtain the compensation film of the present invention.

Generally, when a crystal phase appears in the cooling process, the orientation in the liquid crystal state is destroyed along with crystallization. However, the discotic liquid crystalline material used in the present invention has no crystal phase. Even if it has a potential crystalline phase, it has the property that the crystalline phase does not appear on cooling, or no clear crystal transition point or liquid crystal transition point is confirmed, but it has no fluidity within the operating temperature range of the film. In addition, since the orientation feature does not change even if an external field or external force is applied, the orientation feature is not destroyed by crystallization.

The suitable compensation film of the present invention can be obtained by cooling it to a temperature not higher than the liquid crystal transition point of the discotic liquid crystalline material. Cooling can be fixed uniformly by simply taking out from the heat treatment atmosphere to room temperature. In addition, forced cooling such as air cooling or water cooling or slow cooling may be performed without any limitation, and the cooling rate is not particularly limited. The thickness of the compensation film after immobilization depends on the parameters of the liquid crystal cell used and the refractive index characteristics of the discotic liquid crystalline material used for the compensation film, and therefore cannot be generally stated, but is usually 0.1 μm or more and 50 μm or less. Range, more preferably 0.2 μm or more and 30 μ
m or less, particularly preferably 0.5 μm or more and 15 μm
The range is m or less. If the film thickness is less than 0.1 μm, the compensation effect may not be sufficiently obtained. If the film thickness exceeds 50 μm, the display may be unnecessarily colored.

In the present invention, the angle in the film thickness direction of the hybrid oriented film is such that the absolute value of the angle formed by the director of the film and the plane of the film is 60 ° or more and 90 ° or more on either the upper surface or the lower surface of the film.
It is within the range of 0 degrees or more and 50 degrees or less on the surface opposite to the surface. It can be adjusted to a desired angle by appropriately selecting the discotic liquid crystalline material, the alignment substrate and the like to be used. Also,
Even after the film is once formed, it can be adjusted to a desired angle by, for example, a method of uniformly scraping the surface of the film or dipping it in a solvent to uniformly dissolve the surface of the film. The solvent used at this time is appropriately selected depending on the type of discotic liquid crystal material and the alignment substrate.

The compensating film of the present invention obtained by the above steps is one in which an alignment form called hybrid alignment, which has not been obtained from the conventional discotic liquid crystal, is uniformly aligned and fixed, and the alignment is fixed. Since the film is formed, the upper and lower sides of the film are not equivalent and there is also anisotropy in the in-plane direction, and various characteristics can be brought out depending on the arrangement method. When the compensation film of the present invention is actually arranged in a driving liquid crystal cell having a hybrid nematic alignment, the alignment substrate described above is peeled from the film as a usage pattern of the film, and the compensation film is used alone to form on the alignment substrate. It is possible to use it as it is.

When used as a film alone, the alignment substrate is mechanically peeled off at the interface with the compensation film using a roll or the like, or it is immersed in a poor solvent for all structural materials and then mechanically peeled off. Method of peeling by applying ultrasonic wave in poor solvent, method of peeling by giving temperature change by utilizing difference in thermal expansion coefficient between alignment substrate and film, alignment substrate itself, or dissolving alignment film on alignment substrate A method of removing it can be exemplified. The releasability depends on the adhesiveness between the discotic liquid crystalline material used and the alignment substrate, and therefore the method most suitable for the system should be adopted.

Next, when the compensation film is formed on the alignment substrate, if the alignment substrate is transparent and optically isotropic, or if the alignment substrate is a member necessary for a liquid crystal display device. It can be used as it is as a target liquid crystal display device. Furthermore, the compensation film of the present invention obtained by aligning and fixing a discotic liquid crystalline material on an alignment substrate may be peeled from the substrate and transferred to another substrate more suitable for optical use. it can.

For example, although the alignment substrate used is necessary for obtaining the hybrid alignment form, when such a substrate is used which has an unfavorable influence on the liquid crystal display device, the alignment is fixed. It can be used by removing it from the compensation film after conversion. Specifically, the following method can be adopted. A substrate suitable for a liquid crystal display element to be incorporated in a target liquid crystal display device (hereinafter referred to as a second substrate) and a compensation film on an alignment substrate are attached using an adhesive or a pressure-sensitive adhesive. Next, the alignment substrate and the compensation film of the present invention are peeled off at the interface, and the compensation film can be transferred to the second substrate side suitable for the liquid crystal display device to manufacture a liquid crystal display device.

The second substrate used for transfer is not particularly limited as long as it has appropriate flatness.
Glass or a transparent plastic film having optical isotropy is preferable. Examples of such plastic film include polymethacrylate, polystyrene, polycarbonate, polyether sulfone, polyphenylene sulfide, polyarylate, amorphous polyolefin, triacetyl cellulose, epoxy resin and the like. Among them, polymethyl methacrylate, polycarbonate, polyarylate, triacetyl cellulose, polyether sulfone and the like are preferably used. Further, even if it is optically anisotropic, it can be used as it is if it is a member necessary for a liquid crystal display device. Examples of such materials include retardation films and polarizing films obtained by stretching a plastic film such as polycarbonate and polystyrene.

Further, as an example of the second substrate used, a driving liquid crystal cell of hybrid nematic alignment can be mentioned. The liquid crystal cell uses two glass substrates with electrodes on the upper and lower sides. If the compensation film of the present invention is transferred onto one of the upper and lower sides or both sides of the glass, incorporation of the present compensation film has already been achieved. become. Further, it is of course possible to manufacture the compensation film of the present invention by using the glass substrate itself forming the driving liquid crystal cell as an alignment substrate. The adhesive or pressure-sensitive adhesive for sticking the second substrate used for transfer and the compensation film of the present invention is not particularly limited as long as it is an optical grade, but is acrylic, epoxy, ethylene-vinyl acetate copolymer. A system, a rubber system, a urethane system, or a mixed system thereof can be used.

The compensation film of the present invention can be transferred to a second substrate suitable for a liquid crystal display device by peeling the alignment substrate at the interface with the film after adhesion. The peeling method was explained above, but it is mechanically peeling using a roll, etc., mechanically peeling after dipping in a poor solvent for all structural materials, and peeling by applying ultrasonic waves in a poor solvent. Method, a method of peeling by giving a temperature change by utilizing a difference in thermal expansion coefficient between the alignment substrate and the optical film, an alignment substrate itself, or a method of dissolving and removing the alignment film on the alignment substrate. You can The releasability depends on the adhesiveness between the discotic liquid crystalline material used and the alignment substrate, and therefore the method most suitable for the system should be adopted. Further, the compensation film of the present invention may be provided with a protective layer such as a transparent plastic film for protecting the surface.

The compensation film thus obtained is
It is possible to simultaneously perform color compensation and viewing angle compensation for a driving liquid crystal cell having a hybrid nematic alignment. The parameters and axial arrangement of each member in a liquid crystal display system equipped with a driving liquid crystal cell of hybrid nematic alignment, which incorporates the compensation film of the present invention, will be described below. However, the example of incorporation described below is merely an example, and the example of incorporation of the compensation film of the present invention is not limited thereto.

First, the case of using two polarizing plates will be described. For color compensation, the apparent retardation of the compensation film when viewed from the front (hereinafter, also referred to as in-plane retardation) and the in-plane retardation caused by the liquid crystal alignment in the driving liquid crystal cell corresponding to black display are: The absolute values must be equal to each other and the respective slow axes must be orthogonal to each other. The slow axis of the in-plane retardation of the driving liquid crystal cell is usually parallel to the direction of alignment treatment such as rubbing of the substrate. On the other hand, regarding the in-plane retardation of the compensation film of the present invention, the direction obtained when the director of the discotic liquid crystal is projected in the film plane is the apparent fast axis, and the direction in the plane perpendicular to that is the slow phase. It is the axis. That is, it is a preferable arrangement for color compensation that the alignment treatment direction of the substrate of the driving liquid crystal cell and the direction obtained when the director of the compensation film of the present invention is projected in the film plane are parallel or antiparallel. . The in-plane retardation of the cell during black display is the film thickness and driving conditions of the cell, whether it is used in normally white mode or normally black mode, and the cell liquid crystal has a positive dielectric anisotropy. It depends on whether to use a negative value or a negative value.
In the range of 0 nm to 3000 nm, more preferably 20 n
It is in the range of m to 2000 nm, particularly preferably in the range of 30 nm to 1000 nm. Furthermore, the absolute value of the difference between the in-plane retardation of the cell during white display and the in-plane retardation of the cell during black display is 2 for light of 550 nm.
A value of around 70 nm is preferable for obtaining a bright display. The in-plane retardation of the entire display device during white display is the difference between the in-plane retardation of the cell and the in-plane retardation of the compensation film (the absolute value is approximately equal to the in-plane retardation of the cell during black display). However, it is almost equal to the difference in in-plane retardation of the cell at the time of white display and black display. When this value is close to the λ / 2 plate condition, linearly polarized light that has passed through the lower polarizing plate changes its vibration direction by 90 degrees, and theoretically almost all can pass through the upper polarizing plate (actually, absorption, reflection, etc.). There is a loss due to).

The arrangement for viewing angle compensation will be described. The arrangement for color compensation described above is also a preferable arrangement for compensating for the viewing angle. That is, as a result of achieving color compensation, the director of the liquid crystal in the liquid crystal cell is z in FIG.
The director of the discotic liquid crystal of the compensation film of the present invention is also in the zx plane and changes in the thickness direction while it is in the x plane and changes in the thickness direction. Therefore, the phase difference and optical rotatory dispersion caused by the light traveling along the yz plane of FIG. 1 passing through the liquid crystal cell can be canceled by the compensation film, and the viewing angle is widened. On the other hand, the liquid crystal cell causes a phase difference with respect to light traveling obliquely along the zx plane in FIG. 1, but the compensation film can cancel this phase difference.

For compensating the viewing angle, there are no particular restrictions on other parameters as long as the conditions for such arrangement are satisfied, but the absolute value of the product of the birefringence of the liquid crystal and the film thickness is
It is more preferable that the driving liquid crystal cell and the compensation film are substantially equal. The birefringence here is the anisotropy of the refractive index that the liquid crystal originally has, and is obtained when the director of the liquid crystal is uniaxially oriented so as to face one direction.
It is the difference between the refractive index in the optical axis direction and the refractive index in the direction perpendicular thereto. Such a product of birefringence and film thickness is usually 100 nm or more and 30 nm or more for the driving liquid crystal cell and the compensation film.
00 nm or less, more preferably 200 nm or more and 2000
nm or less, particularly preferably 300 nm or more and 1500 nm
It is the following. However, the value obtained by multiplying the birefringence and the film thickness does not necessarily have to be completely the same in the driving liquid crystal cell and the compensation film, and even when there is a large difference between the two, there is no compensation film. Compared with the above case, a remarkable viewing angle compensation effect can be obtained. On the other hand, the matching of the driving liquid crystal cell and the compensation film for color compensation described above requires higher accuracy.

From the viewpoints of the color compensation and the viewing angle compensation as described above, if the arrangement of the compensation film of the present invention and the driving liquid crystal cell is schematically shown, the patterns as shown in FIGS. 4 and 5 are exemplified. You can In any case, the director of the nematic liquid crystal in the driving liquid crystal cell of the hybrid nematic alignment (almost coincident with the long axis direction of the molecule, omitted in FIG. 4) and the disc forming the compensation film of the present invention. The directors of tick liquid crystals are all in the zx plane. Among these, more preferred is (a),
The patterns are (b), (c), and (d), and (a) and (b) are particularly preferable. However, the present invention is not limited to these typical arrangement patterns.

The arrangement of the polarizing plates is the same as in FIG. That is, the angle formed by the transmission axis of the polarizing plate is about 45 degrees or about 135 degrees with respect to the projection direction of the director of the liquid crystal in the driving liquid crystal cell onto the liquid crystal cell substrate. Further, the upper and lower polarizing plates have a relationship in which their transmission axes are substantially orthogonal to each other. The deviation from the orthogonal condition of the upper and lower polarizing plates is usually ± 20.
Within 0 degree, more preferably within ± 10 degrees, and particularly preferably when they are completely orthogonal. Even when the transmission axes of the polarizing plates are parallel to each other, display is possible by changing the parameters of the compensation film of the present invention. In this case, the absolute value of the difference between the in-plane retardation of the compensation film and the in-plane retardation of the cell during black display is set to be half the wavelength of light (for example, 550n
270 nm for m light). However, it is not preferable because the black display may be colored.

The liquid crystal display device incorporating the compensation film of the present invention is usually used as a direct-view type, but can also be used as a reflection type. In the case of the direct view type, the light source is arranged below the lower polarizing plate, while in the case of the reflection type, the reflecting plate is arranged below the lower polarizing plate. The reflective plate is not particularly limited as long as it can reflect light with high efficiency, and usually, a metal vapor deposition film of aluminum, silver or the like, film-shaped or sheet-shaped aluminum, or the like can be used. It is also possible to use a reflector having a diffusion effect such as a Teflon sheet. Next, as a special case of the present invention, a reflective display device using only one polarizing plate can be mentioned. In this case, the polarizing plate is arranged on the driving liquid crystal cell of the hybrid nematic alignment, and the reflecting plate is arranged below the liquid crystal cell. The compensation film is arranged at a position between the polarizing plate and the reflection plate. The angle formed by the transmission axis of the polarizing plate is about 45 degrees or about 135 degrees with respect to the projection direction of the director of the liquid crystal in the driving liquid crystal cell onto the liquid crystal cell substrate. The arrangement relationship between the driving liquid crystal cell having the hybrid nematic alignment and the compensation film is the same as that shown in FIG. However, the in-plane retardation of the compensating film and the liquid crystal cell at the time of black display are not the same, and the absolute value of the difference between them is 1 of the wavelength of light.
/ 4 (for example, about 140 nm for 550 nm light). In this case, black coloring occurs,
Since the loss of light due to the absorption of the polarizing plate is reduced, the brightness is improved. This system can be used as a reflective display device in which brightness is more important than display quality.

As described above, the liquid crystal display device of the hybrid nematic orientation in which the compensation film of the present invention is arranged is
High contrast and wide viewing angle. Further, good gradation display can be performed by utilizing the voltage dependence of the gradual retardation of the hybrid nematic liquid crystal cell.

[0221]

EXAMPLES Examples will be described below, but the present invention is not limited thereto. The analytical methods used in the examples are as follows. Measured in (Chemical Structure Determination) ¹ H-NMR of 400 MHz (JEOL JNM-GX400).

(Optical Microscope Observation) Orthoscopic observation and conoscopic observation were performed using a polarizing microscope BX-50 manufactured by Olympus. The liquid crystal phase was identified by observing the texture while heating it on a METTLER HOT stage (FP-80). (Polarization analysis) This was performed using an ellipsometer DVA-36VWLD manufactured by Mizojiri Optical Co., Ltd. The retardation value used was that at a wavelength of 550 nm.

(Measurement of Refractive Index) An Abbe refractometer Type-4T manufactured by Atago Co., Ltd. was used. A sodium lamp was used as the light source. The refractive index value was corrected to a value at 550 nm based on the wavelength dispersion data of the refractive index. (Film Thickness Measurement) A high precision thin film step measuring instrument ET-10 manufactured by Kosaka Laboratory Ltd. was mainly used. In addition, the method of determining the film thickness from the interference wave measurement (JASCO ultraviolet / visible / near infrared spectrophotometer V-570) and the data of the refractive index was also used.

Example 1 50 mmol of hexahydroxytriphenylene, 150 mM of p-hexylbenzoic acid chloride and 50 mmol of p-hexyloxybenzoic acid chloride were dissolved in 1 liter of dried pyridine, and the solution was stirred at 90 ° C. for 5 hours under a nitrogen atmosphere. Then, the reaction solution is poured into 10 liters of water, the precipitate is separated by filtration, washed with 0.1N hydrochloric acid, washed with pure water, and dried to obtain the discotic liquid crystalline material of the formula (1) (62 g of brown powder). ) Got. Observation of this material on a METTLER HOT stage revealed a schlieren pattern and an ND phase, and no crystalline phase appeared even when cooled. 30g of this material
Of 1,1,2,2-tetrachloroethane to prepare a 25% by weight solution, which has a rubbing polyimide film 1
It is applied on a 5 cm square glass substrate by spin coating, then dried on a hot plate at 60 ° C., heat-treated at 240 ° C. for 30 minutes in an oven, taken out at room temperature, cooled, and compensated on a transparent substrate. A film 1 was obtained.

The film thickness of the film was 6.0 μm.
The birefringence of the discotic liquid crystalline material represented by the formula (1) was 0.10, and the product of the birefringence and the film thickness was 600 nm according to the refractive index measurement described later. When ellipsometer was used to perform ellipsometry, the apparent retardation value in the front was 300 nm. The slow axis was in the in-plane direction perpendicular to the rubbing direction.

Next, the compensating film 1 as formed on the substrate is sandwiched between a pair of polarizing plates whose polarizing directions are orthogonal to each other, and the projection vector of the director of the liquid crystal in the compensating film onto the compensating film surface and the polarizer Arranged so that the transmission axis forms an angle of 45 degrees, the compensation film 1 was tilted along the substrate along the projection vector direction (coincident with the rubbing direction) of the director onto the compensation film surface, and the apparent retardation value was measured. . As a result, the graph of Figure 6 is obtained,
In consideration of the refractive index described below, the incident angle dependence of retardation was simulated, and a result of an average tilt angle of 35 degrees was obtained. From Figure 5, the director of the liquid crystal is
It was found that the substrate was inclined in the direction shown in FIG. 6 with respect to the rubbing direction.

The refractive index was measured as follows. A compensation film was formed in the same manner as the compensation film 1 on the high refractive index glass having a rubbing polyimide film, and the refractive index was measured with an Abbe refractometer. When placed so that the glass substrate is in contact with the prism surface of the refractometer and the substrate interface side of the compensation film is below the air interface side, the in-plane refractive index is constant and is 1.66. The refractive index in the thickness direction was 1.56, which was almost constant. From this, it was found that the disk-shaped liquid crystal molecules were plane-aligned parallel to the substrate on the glass substrate side (the director was perpendicular to the substrate plane). Next, when the air interface side of the compensation film is placed in contact with the prism surface of the refractometer, the refractive index in the plane parallel to the rubbing direction is 1.56, and the direction in the plane perpendicular to the rubbing direction is 1.66. The thickness direction was constant at 1.66 regardless of the sample direction. From this, it was found that on the air interface side, the discotic liquid crystal molecules were oriented in the direction perpendicular to the substrate and the rubbing direction (the director was parallel to the substrate plane). Such a refractive index structure is the same in the film 1. From this, compensation film 1
Has an intrinsic refractive index of 1.56 (ne) in the direction parallel to the director and 1.6 in the direction perpendicular to the director.
It was 6 (no), and the difference was found to be 0.10.

Using the compensating film 1 having such a structure, a pair of polarizing plates whose polarization directions are orthogonal to each other and a driving liquid crystal cell having a hybrid nematic alignment are combined, and FIG.
(Corresponding to FIG. 4 (a)). The liquid crystal cell was manufactured as follows. Two glass substrates each having an ITO film were prepared, and one substrate was formed by forming a polyimide film on the ITO film and then rubbed to obtain a planar alignment substrate. The other one is tetrachloro-μ-on the ITO film.
hydroxo-μ-myristato dichro
A film of mium (III) was formed and used as a vertical alignment substrate. After a bead-shaped spacer was inserted between these two substrates to form a gap of 4.7 μm, a liquid crystal ZLI-2777 (Δn = 0.1) manufactured by Merck & Co., Inc. with positive dielectric anisotropy was used.
28, Δε = + 8.8) was injected. The liquid crystal cell was driven at 0V, 2.0V and 4.0V, and by mounting the compensation film, black was obtained at 0V, white was obtained at 4.0V, and halftone was obtained at 2.0V (that is, normally black mode). ). The in-plane apparent retardation of the liquid crystal cell alone was measured and found to be 300 nm at 0 V.
It was 30 nm when 0 V was applied. The viewing angle dependence of the transmittance was measured, and the results shown in FIG. 8 were obtained. It has been found that a liquid crystal display device having a wide viewing angle in the vertical and horizontal directions and color compensation can be obtained by mounting the compensation film.

Example 2 Hexaacetoxytorxene 50 mmol, t-butylbenzoic acid 112 mmol, stearic acid 112 mmo
1, 38 mmol of decanedioic acid was used, and this was heated in a glass flask at 280 ° C. for 8 hours in a nitrogen atmosphere while vigorously stirring with a mechanical stirrer,
Then, it was heated at 290 ° C. for 1 hour under a vacuum of 1 mmHg to obtain an oligomeric discotic liquid crystalline material (formula (2)) in which a part of the discogen was linked with a bifunctional substituent. The compound of the formula (2) was dissolved in tetrachloroethane and then reprecipitated in a large amount of methanol for purification. When the purified material was observed on a Mettler hot stage, it had an ND phase at a high temperature, and once it showed the ND phase, no crystalline phase appeared even when cooled. Further, the immobilization product cooled from the ND phase had no fluidity at 150 ° C. or lower even when heated again. Dissolve this material in a mixed solvent of tetrachloroethane / phenol (weight ratio 1: 1),
A 15 wt.% 9% solution was prepared. Next, a glass substrate having a rubbing polyimide film (30 cm square, thickness 1.1 m)
m) by printing method, air-dried, and 220 ° C for 30
After heat treatment for minutes, it was taken out at room temperature, cooled and fixed. The compensation film 2 on the obtained substrate was transparent, had no alignment defects, and had a thickness of 5.0 μm. According to the refractive index measurement, the director of the liquid crystal is almost perpendicular to the substrate at the interface of the alignment substrate and substantially parallel to the substrate at the air interface side.
e = 1.56 and no = 1.65. Than this
The difference in refractive index between ne and ne was 0.09, and the product of this and the film thickness was 450 nm. The in-plane apparent retardation value was 30 nm, and the slow axis was in the in-plane direction perpendicular to the rubbing direction.

The film 2 was placed on the driving liquid crystal cell of hybrid nematic alignment prepared in Example 1 and arranged as shown in FIG. 9 (corresponding to FIG. 4A). The liquid crystal cell was driven at 0 V, 2.0 V and 4.0 V, and by mounting the compensation film, white was obtained at 0 V, black was obtained at 4.0 V, and halftone was obtained at 2.0 V (that is, normally white mode). ). As a result, a wide viewing angle characteristic and a color compensation characteristic as shown in FIG. 10 were obtained.

Example 3 With respect to the structure of FIG. 8 of Example 2, the lower light source was removed and an aluminum reflector was installed to fabricate a reflection type display device as shown in FIG. 11 (see FIG. Equivalent to)). The cell driving conditions were the same as in Example 2. As a result, a display with a wide viewing angle and color compensation was obtained.

Example 4 As the discotic liquid crystalline material, a mixture of the formulas (3) and (4) in a weight ratio of 4: 1 was used. This compound was dissolved in xylene to obtain a 12 wt% solution. Then, a rubbing polyimide film having a width of 25 cm (rubbed with a Kapton film manufactured by DuPont having a thickness of 100 μm) was applied by a roll coater over a length of 10 m. The film was dried with hot air of 100 ° C., heat-treated at 250 ° C. for 5 minutes, and then cooled to obtain a compensating film 3 on a rubbing polyimide film having a fixed liquid crystal phase.

Since the polyimide film lacks transparency and there is a problem in using it as a substrate for a compensating plate, the compensating film 3 was transferred to an optical grade polyether sulfone via an adhesive. The operation was performed by sticking the polyether sulfone subjected to the adhesive treatment and the film 3 on the rubbing polyimide film so that the adhesive layer and the film 3 were in contact with each other, and then peeling off the rubbing polyimide film. The relationship between the compensation film 3 and the substrate for the transfer operation is opposite on the polyimide film and the polyether sulfone having the adhesive layer.
The director of the film 3 after peeling is substantially parallel to the film surface on the side in contact with the adhesive layer and substantially perpendicular to the film surface on the air side.

The film thickness of the film 3 was 5.9 μm.
The refractive index was 1.54 in the director direction and 1.67 in the direction perpendicular to the director. The apparent retardation in the plane was 400 nm. Using the compensation film 3 on the polyether sulfone having this depletion layer, it was mounted on a liquid crystal cell for driving a hybrid nematic alignment, and
2 was arranged (corresponding to FIG. 4 (b)). The driving liquid crystal cell was manufactured as follows. Two glass substrates each having an ITO film were prepared, and one substrate was formed by forming a polyimide film on the ITO film and then rubbed to obtain a planar alignment substrate.
The other surface was made hydrophobic by immersing it in a toluene solution of octadecyltrichlorosilane to obtain a vertically aligned substrate. A bead-like spacer was inserted between these two substrates to form a gap of 10.8 μm, and then a liquid crystal ZLI-2857 (Δ having a negative dielectric anisotropy manufactured by Merck & Co., Inc. was manufactured.
n = 0.074, Δε = −1.5) was injected. The liquid crystal cell is driven at 0V, 3.5V and 7.0V, and by installing the compensation film, 0V is white, 7.0V is black and 3.5.
Midtones were obtained at V (ie normally white mode). The in-plane apparent retardation of the liquid crystal cell alone was measured and found to be 400 nm at 0 V.
It was 670 nm when 7.0 V was applied. The viewing angle dependence of the transmittance was measured, and the results shown in FIG. 13 were obtained. By mounting the compensation film, excellent color compensation and viewing angle compensation were obtained.

Example 5 As a discotic liquid crystalline material, a polymer having a molecular weight of 13,000 in which mesogens were linked by cyclohexanedicarboxylic acid units of the formula (4) was used. The molecular weight is GP
It was determined in terms of polystyrene by C measurement. This polymer had no crystalline phase and showed a glass transition at a lower temperature than the ND phase. Tg was 68 ° C. This polymer is
It was dissolved in a chlorophenol / tetrachloroethane mixed solvent (weight ratio 6: 4) with heating to obtain a 16 wt% solution.

Next, a roll coater is used to obtain a width of 25 cm.
Was applied to the rubbing-treated polyphenylene sulfide film over a length of 10 m. The film was dried with hot air of 100 ° C., heat treated at 220 ° C. for 30 minutes, and then cooled to obtain a compensating film 4 on rubbing polyphenylene sulfide in which the liquid crystal phase was fixed to glass.

Since the polyphenylene sulfide film lacked transparency and had a problem in using it as a substrate for a compensating plate, the compensating film 4 was transferred to an optical grade triacetyl cellulose film via a UV curable adhesive.
The peeling transfer operation was performed in the same manner as in Example 3. The film thickness of the film 4 was 15 μm. The discotic liquid crystal director was substantially parallel to the film surface on the side in contact with the adhesive layer, and was substantially perpendicular to the film surface on the air side. The refractive index was 1.56 in the director direction and 1.64 in the direction perpendicular to the director. The apparent retardation in the plane was 50 nm.

The compensating film 4 on the triacetyl cellulose film having this adhesive layer was placed on the hybrid nematic alignment cell and arranged as shown in FIG. 14 (FIG. 4).
(Corresponding to (b)). The cell was manufactured as follows. Two glass substrates each having an ITO film were prepared, and one substrate was formed by forming a polyimide film on the ITO film and then rubbed to obtain a planar alignment substrate. The other plate was subjected to a hydrophobic treatment by immersing it in a toluene solution of octadecyltriethoxysilane to obtain a vertically aligned substrate. A bead-like spacer was put between these two substrates to form a gap of 9.4 μm, and then liquid crystal ZLI-2777 manufactured by Merck & Co., Inc. with positive dielectric anisotropy was injected. Driving the liquid crystal cell
It was performed at 0 V and 2.5 V, and by mounting the compensation film, white display at 0 V and black display at 2.5 V were obtained (that is, normally white mode). When the in-plane apparent retardation was measured for the liquid crystal cell alone,
It was 600 nm at 0 V and 190 nm when 2.5 V was applied. The reflective display device obtained was color-compensated, was bright, and had good viewing angle characteristics.

[0239]

INDUSTRIAL APPLICABILITY The compensating film of the present invention in which a discotic liquid crystal is fixed in a hybrid orientation exhibits excellent color compensation and viewing angle compensation for a liquid crystal cell having a hybrid nematic orientation. The compensated liquid crystal display element has a high-performance display performance and can be used for a display of a liquid crystal television, a portable electronic device, or the like, and is industrially extremely valuable.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a liquid crystal display including a driving liquid crystal cell having a hybrid nematic alignment as a main constituent member. (A) When voltage is not applied, (b) When voltage is applied to liquid crystal having positive dielectric anisotropy, (c) When voltage is applied to liquid crystal having negative dielectric anisotropy.

FIG. 2 is a diagram illustrating a refractive index distribution and a director unique to a discotic liquid crystal.

FIG. 3 is a schematic view of possible alignment forms of discotic liquid crystal. The arrow in the figure is the director. (A) is a negative uniaxial structure in which the director is perpendicular to the substrate surface. (B) is a negative uniaxial structure tilted at a constant angle with respect to the substrate surface. (C) is a hybrid orientation in which the director of the compensator of the present invention gradually changes in the thickness direction. The arrow in the figure is the direction of the liquid crystal director. There is no distinction between the head and the tail in the direction of the director, but for the sake of convenience, an arrow is used.

FIG. 4A to FIG. 4D are schematic views illustrating an exemplary arrangement of a typical compensation film. The arrow in the figure is the direction of the liquid crystal director. There is no distinction between the head and the tail in the direction of the director, but for the sake of convenience, an arrow is used. Also, the illustration of the polarizing plate is omitted.

5 (e) to 5 (h) are schematic diagrams for explaining a typical arrangement example of the compensation film, similarly to FIGS. 4 (a) to 4 (d).
The arrow in the figure is the direction of the liquid crystal director. There is no distinction between the head and the tail in the direction of the director, but for the sake of convenience, an arrow is used. Also, the illustration of the polarizing plate is omitted.

FIG. 6 is a result of measuring the apparent retardation by tilting the compensation film as it is formed on the substrate along the rubbing direction of the substrate. The figure explaining the direction which inclines a film was shown in the figure. The tilt direction of the liquid crystal director in the figure is a schematic representation based on the results obtained in this measurement.

FIG. 7 is a perspective view of the liquid crystal display device used in Example 1 (a).
And axial direction of each member (b) 1 upper polarizing plate 2 liquid crystal cell 3 tetrachloro-μ-hydroxo-μ
-Myristatodichromium (III)
Upper ITO electrode substrate 4 having a film of 4 lower ITO electrode substrate 5 having a rubbing polyimide film 5 lower polarizing plate 6 a glass substrate having a rubbing polyimide film and a compensating film 1 7 compensating film 1 8 having a rubbing polyimide film formed thereon Glass substrate 9 Transmission axis direction of upper polarizing plate 10 Rubbing direction of polyimide film 11 Transmission axis direction of lower polarizing plate 12 Rubbing direction of polyimide film

8 is a measurement result of viewing angle dependence of transmittance obtained in Example 1. FIG.

FIG. 9 is a perspective view of the liquid crystal display device used in Example 2 (a).
And axial direction of each member (b) 1 upper polarizing plate 2 liquid crystal cell 3 tetrachloro-μ-hydroxo-μ
-Myristatodichromium (III)
Upper ITO electrode substrate 4 having a film of 4) lower ITO electrode substrate 5 having a rubbing polyimide film 5 lower polarizing plate 6 a glass substrate having a rubbing polyimide film and a compensation film 2 7 compensation film 2 8 having a rubbing polyimide film formed thereon Glass substrate 9 Transmission axis direction of upper polarizing plate 10 Rubbing direction of polyimide film 11 Transmission axis direction of lower polarizing plate 12 Rubbing direction of polyimide film

10 is a measurement result of viewing angle dependence of transmittance obtained in Example 2. FIG.

FIG. 11 is a perspective view (a) of the reflective liquid crystal display device used in Example 3 and axial directions (b) of each member. 1 Upper polarizing plate 2 Liquid crystal cell 3 tetrachloro-μ-hydroxo-μ
-Myristatodichromium (III)
Upper ITO electrode substrate 4 having a film of 4) lower ITO electrode substrate 5 having a rubbing polyimide film 5 lower polarizing plate 6 a glass substrate having a rubbing polyimide film and a compensation film 2 7 compensation film 2 8 having a rubbing polyimide film formed thereon Glass substrate 9 Transmission axis direction of upper polarizing plate 10 Rubbing direction of polyimide film 11 Transmission axis direction of lower polarizing plate 12 Rubbing direction of polyimide film 13 Aluminum reflector

FIG. 12 is a perspective view of the liquid crystal display device used in Example 4 (a) and the axial orientation of each member (b). 1 Upper polarizing plate 2 Liquid crystal cell 3 Hydrophobized upper ITO electrode substrate 4 Rubbing polyimide film Lower ITO electrode substrate 5 Lower polarizing plate 6 Compensation film 3 7 Compensation film 3 8 formed on top of a polyether sulfone film and a pressure sensitive adhesive layer Polyether sulfone film 9 having a pressure sensitive adhesive layer 9 Transmission axis direction 10 of the upper polarizing plate Rubbing direction of polyimide film 11 Transmission axis direction of lower polarizing plate 12 Direction corresponding to rubbing direction of polyimide film

13 is a measurement result of viewing angle dependence of transmittance obtained in Example 4. FIG.

14 is a perspective view of the reflection type liquid crystal display device used in Example 5 (a) and the axial orientation of each member (b) 1 upper polarizing plate 2 liquid crystal cell 3 hydrophobic upper ITO electrode substrate 4 rubbing polyimide film Lower ITO electrode substrate 5 having a triacetyl cellulose film and a compensation film 4 6 formed thereon via an adhesive layer 4 compensation film 4 7 triacetyl cellulose film having an adhesive layer 8 transmission axis direction of upper polarizing plate 9 polyimide film Rubbing direction 10 Direction corresponding to rubbing direction of polyphenylene sulfide film 11 Aluminum reflector

─────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-8-50206 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G02B 5/30

Claims (5)

(57) [Claims] 1. A compensating film comprising a driving liquid crystal cell having a hybrid nematic alignment structure and a liquid crystalline optical film used for a liquid crystal display device having a pair of polarizing plates, the film comprising a discotic liquid crystalline material. It is a film in which the orientation form of the formed discotic liquid crystal is fixed, and the orientation form is a hybrid orientation in which the angle formed by the director of the discotic liquid crystal and the plane of the film is different between the upper surface and the lower surface of the film. Characteristic compensation film for liquid crystal display devices. 2. A compensating film comprising a driving liquid crystal cell having a hybrid nematic alignment structure and a liquid crystalline optical film used in a liquid crystal display device having a single polarizing plate, the film being discotic liquid crystalline. A film in which an alignment form of a discotic liquid crystal formed of a material is fixed, and the alignment form is a hybrid alignment in which an angle formed by the director of the discotic liquid crystal and the plane of the film is different between the upper surface and the lower surface of the film. A compensation film for a liquid crystal display device, which is characterized in that 3. A hybrid orientation wherein the director of the discotic liquid crystal is on one side of the film,
3. The hybrid orientation which forms an angle of 60 degrees or more and 90 degrees or less with the plane of the film, and has a hybrid orientation which forms an angle of 0 degrees or more and 50 degrees or less on the other surface of the film. Compensation film for liquid crystal display device. 4. A pair of driving liquid crystal cells having a hybrid nematic alignment structure, wherein at least one compensating film for a liquid crystal display element according to claim 1 or 3 is incorporated, and a pair of polarization directions thereof are orthogonal to each other. A liquid crystal display device including a polarizing plate. 5. A driving liquid crystal cell having a hybrid nematic alignment structure, characterized by incorporating at least one compensating film for a liquid crystal display device according to claim 2 or 3, and one polarizing plate. Liquid crystal display device.