JP4632252B2 - Vertical alignment type super twist liquid crystal display element and manufacturing method thereof - Google Patents

Description

  The present invention relates to a vertical alignment type super twist liquid crystal display element.

  There is a STN-LCD (super twisted nematic liquid crystal display element) as an LCD that displays an image with a high number of scanning lines without using an active element such as a TFT. The STN-LCD has good steepness indicating the rate of change in transmittance with respect to voltage change and high transmitted light intensity in the bright state, so that high contrast characteristics can be obtained.

However, it is difficult for the STN-LCD to display black only with one layer. Therefore, as a method for performing black and white display, the two-layer STN-LCD method in which two cells having different twist directions of liquid crystal are stacked and one cell is driven, or one or a plurality of positive uniaxial films in a liquid crystal cell are usually used. The stacked film compensation STN-LCD method is used.
However, since the former two-layer STN-LCD method uses two liquid crystal cells, the thickness and weight increase. Further, the latter film compensation STN-LCD system cannot obtain a practical level of black display, and even if black display is possible within the electrode, black floats outside the electrode and it is difficult to increase the contrast. there were.

On the other hand, a vertical alignment ECB (Electrically Controlled Birefringence) mode liquid crystal display element has been proposed as an LCD having good steepness and high transmittance in a bright state like the STN-LCD. (For example, see Patent Document 1)
However, in the vertical alignment type ECB mode liquid crystal display device, the pretilt angle of the alignment film is reduced in order to increase the steepness. This causes light leakage during black display when no voltage is applied, resulting in a decrease in contrast. May occur.
JP 2004-355032 A

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a vertical alignment type super twist liquid crystal display element having high steepness (Vr90 / Vr0.9 is less than 1.2) and low hysteresis. To do.

  A vertical alignment type super twist liquid crystal display element according to claim 1 of the present invention is a pair of electrodes in which an electrode and an alignment film are sequentially stacked on one surface of the substrate, and the alignment films are arranged to face each other. At least a liquid crystal material having negative dielectric anisotropy provided so as to be sandwiched between the pair of substrates, and the pair of substrates together form liquid crystal molecules forming the liquid crystal material The liquid crystal material contains at least one chiral agent, and a value obtained by dividing the bending elastic constant K33 by the expansion elastic constant K11. The twist angle defined by the alignment film is 180 ° or more and 280 ° or less.

  The vertical alignment type super twist liquid crystal display element according to claim 2 of the present invention is characterized in that, in claim 1, the twist angle is not less than 240 ° and not more than 270 °.

  The vertical alignment type super twisted liquid crystal display element according to claim 3 of the present invention is characterized in that, in claim 1, when the natural twist pitch of the liquid crystal material is defined as p and the distance between the pair of substrates is defined as d, the d is The value divided by p is 0.55 or more and 0.75 or less.

  According to a fourth aspect of the present invention, there is provided a method for manufacturing a vertical alignment type super twisted liquid crystal display element, in which an electrode and an alignment film are sequentially stacked on one side of a substrate, and the alignment films are arranged so as to face each other. A pair of substrates and a liquid crystal material having negative dielectric anisotropy provided so as to be sandwiched between the pair of substrates, both of the pair of substrates comprising the liquid crystal material. The liquid crystal material has an alignment control ability to give a pretilt angle of 80 ° to 86 ° with respect to the liquid crystal molecules formed. The liquid crystal material contains at least one chiral agent, and the elastic constant K33 of bending is divided by the elastic constant K11 of spread. A method for producing a vertical tilt type super twist liquid crystal display device having a measured value of 1.25 or more and a twist angle defined by the alignment film of 180 ° or more and 280 ° or less, wherein the pretilt angle is generated. As light Characterized by using the direction processing.

In the vertical alignment type super twist liquid crystal display element according to the present invention, the pretilt angle has a specific value, the ratio K33 / K11 of the bending elastic constant K33 and the expansion elastic constant K11 is equal to or more than a specific value, and A liquid crystal material having a twist angle is provided.
That is, the present invention is a liquid crystal display element in which a liquid crystal material having negative dielectric anisotropy is sandwiched between two substrates having electrodes, and satisfies the following (1) to (3). .
(1) Both of the two substrates have an alignment control ability that gives a pretilt angle of 80 ° to 86 ° to the liquid crystal molecules.
(2) The liquid crystal material contains at least one chiral agent, and a value obtained by dividing the bending elastic constant K33 by the spreading elastic constant K11 is 1.25 or more.
(3) The liquid crystal material has a twist angle defined by the alignment film of 180 ° or more and 280 ° or less.

With such a configuration, the vertically aligned super twisted liquid crystal display element of the present invention is sandwiched between polarizing plates arranged in crossed Nicols, and the display surface is observed. When no voltage is applied, the pretilt angle of the liquid crystal is aligned at 80 ° to 86 °. Therefore, a good black display (low transmittance) can be obtained.
On the other hand, when a voltage is applied, the liquid crystal molecules fall while taking a twisted structure (helical arrangement) that changes the major axis direction, and the retardation becomes large and light is transmitted (bright state). At this time, the pretilt angle is in the range of 80 ° to 86 °, the ratio K33 / K11 of the elastic constant K33 and the expansion elastic constant K11 is 1.25 or more, and the twist angle of the liquid crystal material is in the range of 180 ° to 280 °. Therefore, the steepness becomes good, and specifically, the steepness of 1.2 or less can be given.
Therefore, the present invention contributes to the provision of a vertical alignment type super twist liquid crystal display element having high steepness (less than 1.2) and low hysteresis.

  A vertical alignment type super twisted liquid crystal display element according to the present invention comprises a pair of substrates formed by sequentially stacking an electrode and an alignment film on one surface of a base material, the alignment films being opposed to each other, And a liquid crystal material having negative dielectric anisotropy provided to be sandwiched between a pair of substrates.

(substrate)
The substrate used in the present invention is obtained by sequentially stacking an electrode and an alignment film on one surface of a base material, and has an alignment control ability that gives a pretilt angle of 80 ° to 86 ° to liquid crystal molecules. The alignment control ability can be imparted by, for example, a method of forming an alignment film on a substrate electrode by a known method such as a rubbing method, a radial deposition method, a photo-alignment method, or an oblique deposition method. Among them, the photo-alignment method that gives alignment control ability by irradiating light to the vertical alignment film does not generate scratches that cause light leakage unlike the rubbing method, and easily provides alignment control ability to the substrate. Since it can provide, it is preferable.

In order to impart an alignment control ability to give a pretilt angle of 80 ° to 86 ° to liquid crystal molecules using a photo-alignment method, for example, on a substrate having a transparent electrode as shown in FIG. A vertical alignment film is formed on the substrate, and the substrate is irradiated with linearly polarized ultraviolet rays at an angle θ. At this time, the ultraviolet irradiation angle θ is preferably 20 to 70 °. The ultraviolet rays are not particularly limited as long as they cause the vertical alignment film to have the function of aligning the liquid crystal, and may be non-polarized light or deflected light. However, the deflected light is preferable because the alignment function can be efficiently generated. 1 represents the angle formed by the plane of polarization of linearly polarized light with the XY plane (substrate surface), and is usually set to 90 °.
The vertical alignment film to be used may be any film that emits 80 to 86 ° of pretilt when irradiated with linearly polarized ultraviolet rays.

The material of the base material constituting the substrate is not particularly limited as long as it is a material usually used for LCD cells, but a material having transparency is desirable. For example, in addition to a robust material such as glass and plastic, a flexible material such as a plastic film can also be used.
As the electrode provided on the base material, a material having transparency and low resistance is desirable, and examples thereof include an indium oxide film, a tin oxide film, an indium oxide / tin oxide (ITO) film, and an indium oxide / zinc oxide film. . Each film constituting the electrode may be formed by a commonly used method such as vapor deposition or sputtering, and the electrode may be patterned as necessary. In order to pattern the electrodes, for example, an ITO film may be formed on a substrate by a sputtering method or the like through a mask, or an ITO film may be formed on the entire surface and then etched by a photolithography method or the like.

(Liquid crystal material)
The liquid crystal material used in the present invention contains at least one chiral agent, a value obtained by dividing the bending elastic constant K33 by the expansion elastic constant K11 is 1.25 or more, and is defined by the alignment film. A twist angle of 180 ° or more and 280 ° or less is used. If such conditions are satisfied, the structure and the like are not particularly limited. Specifically, it may be any material that is normally recognized as a liquid crystal material in this technical field, and may not be a single liquid crystal compound, but may be a composition of two or more liquid crystal compounds. It can be selected and blended. Specifically, liquid crystal materials that can be used include liquid crystal compounds such as tolan type, fluoro type, and naphthalene type.

By including a chiral agent in the liquid crystal material, the liquid crystal material can generate a natural twist pitch.
In the liquid crystal display element according to the present invention, by adding a chiral agent having such a function and using a liquid crystal material having an arbitrary natural twist pitch, the ratio of the transmittance change to the voltage change of the liquid crystal display element can be reduced. The steepness shown is good, and image display with a high number of scanning lines is possible.
Note that since the pitch of the natural twist of the liquid crystal material changes depending on the amount of chiral agent added, the amount of chiral agent added may be appropriately adjusted according to the required liquid crystal pitch.

  If a value obtained by dividing the bending elastic constant K33 by the expansion elastic constant K11 (denoted as K33 / K11) as the liquid crystal material is less than 1.25, the vertical alignment type super twisted liquid crystal display element of the present invention is obtained. The steepness indicating the ratio of the transmittance change to the voltage change becomes slow, and it is difficult to display an image with a large number of scanning lines. On the other hand, when a liquid crystal material having a ratio of K33 / K11 of 1.25 or more is used, the steepness indicating the ratio of the transmittance change with respect to the voltage change becomes steep, so that an image display with a high number of scanning lines is possible. This is preferable.

In the vertical alignment type super twist liquid crystal display element of the present invention, the relationship between the twist angle of the liquid crystal material and the steepness indicating the ratio of the transmittance change to the voltage change is that the steepness becomes slower as the twist angle is smaller. As the angle is larger, the steepness tends to be steeper. However, if the twist angle is too large, stripe domains are generated when a voltage is applied, or the electro-optical characteristic curves are different when the applied voltage is increased and decreased, which is undesirable. Generation of such stripe domains and hysteresis can be suppressed by setting the twist angle in the range of 180 ° to 280 °. Further, it is more preferable that the twist angle be in the range of 240 ° or more and 270 ° or less, since the steepness indicating the ratio of the transmittance change with respect to the voltage change is steep, and a liquid crystal element that does not cause a problem stably can be manufactured.
There is no limitation in particular as a chiral agent used by this invention, A well-known and usual thing can be used. For example, S-811, R811, CB-15, MLC6247, MLC6248, R1011, S1011 (made by Merck) etc. are mentioned.

(D / p)
When a natural twist pitch of the liquid crystal material is defined as p and a distance between the pair of substrates is defined as d, a value obtained by dividing d by p (denoted as d / p) is in a range of 0.55 to 0.75. A certain liquid crystal material is more preferable for reasons such as providing good steepness of electro-optical characteristics and suppressing the occurrence of hysteresis. The value of (d / p) can be set to an arbitrary value by changing the cell gap or changing the amount of the chiral agent added to the liquid crystal.

The liquid crystal display element according to the present invention can be produced by a known method. For example, trichloroethylene, isopropyl alcohol, hydrogen peroxide caustic soda solution, hydrogen peroxide hydrochloric acid solution, etc. are used as appropriate to clean a transparent substrate (hereinafter also referred to as a transparent substrate with a transparent electrode) on which an electrode made of a transparent conductive film is disposed. After the treatment, a washing treatment is further performed with ultrapure water or the like.
Next, a vertical alignment film is formed on a transparent substrate with a transparent electrode by using a plexo printing method, an ink jet method, or a spin coating method, and baked, and then the vertical alignment film is subjected to photo-alignment treatment.
Thereafter, a spacer is interposed between the upper substrate and the lower substrate to form a uniform gap between the substrates, and the periphery is sealed and fixed with a sealing material. At this time, the portion serving as the liquid crystal injection port is opened without being sealed.
The material of the spacer is not particularly limited, and the spacer may be used as a spacer by dispersing plastic beads or silica particles or forming a column-shaped structure at a predetermined position on the substrate. . Further, the material of the sealing material is not particularly limited. For example, a material obtained by mixing a glass fiber into a columnar spacer by mixing an epoxy resin or a silicon resin can be used.
Next, after the inside of the liquid crystal cell is evacuated, liquid crystal is injected, the injection port is sealed with an adhesive, and the vertical alignment type super twisted liquid crystal display element according to the present invention is obtained.

  Below, based on an Example, the vertical alignment type | mold super twist liquid crystal display element which concerns on this invention is demonstrated in detail, However, This invention is not limited to these Examples.

<Measurement of pretilt angle>
In this example, the pretilt angle is manufactured under the same conditions as in the case of manufacturing a vertical alignment type super twist liquid crystal display element in the conditions for applying the alignment film to the substrate, the baking temperature condition, and the alignment film manufacturing condition. The angle between the director of the liquid crystal molecules and the substrate surface on the substrate surface of the antiparallel type liquid crystal alignment element was defined as the pretilt angle.

A vertical alignment type alignment film solution (SE-1211 manufactured by Nissan Chemical Industries, Ltd.) was applied onto a substrate having a transparent electrode layer by a spin coater and then baked.
Next, a substrate with an alignment film was prepared by irradiating the substrate surface with linearly polarized ultraviolet light having an emission spectrum near a wavelength of 254 nm at θ = 45 ° in an amount of 0.2 to 0.5 j / cm ² .
A thermosetting adhesive containing 5.5 μm diameter styrene beads was applied to the substrate with the alignment film leaving the liquid crystal injection port and dried at 80 ° C. for 5 minutes, and then the two substrates were anti-parallel aligned. Then, the alignment film was superposed and pressure-bonded with the alignment film as the inside, and the adhesive was cured at 150 ° C. for 90 minutes.
The baking temperature and time of the adhesive or the light intensity during photo-alignment were set to the same conditions as those of the liquid crystal cells A to G prepared in Examples or Comparative Examples.
Liquid crystal containing no chiral agent was injected from the liquid crystal injection port, and the liquid crystal injection port was sealed with an epoxy adhesive to obtain a liquid crystal cell. The pretilt angle of the liquid crystal in the cell was measured by the rotating crystal method, and was defined as the pretilt angle.

(Electro-optical properties (transmittance, steepness, etc.))
The transmittance, steepness and the like were measured using DMS501 (manufactured by Autoronic). Specifically, a 100 Hz rectangular wave was gradually applied from 0 Vrms to 5 Vrms, then the voltage was gradually decreased to 0 Vrms, and the light transmittance at each applied voltage was measured.
Tmin: Transmittance when no voltage is applied (%)
Tmax: Maximum transmittance (%) when a voltage of 0 to 5 Vrms is applied
Vr0.9: Applied voltage (Vrms) at which Tmin is 0%, Tmax is 100%, voltage is applied, and the transmittance is 0.9%
Vr90: Applied voltage (Vrms) at which Tmin is 0%, Tmax is 100%, voltage is applied, and transmittance is 90%
Steepness γ: Vr90 / Vr0.9

Example 1
On a substrate having a transparent electrode layer, a vertical alignment type alignment film solution (SE-1211 manufactured by Nissan Chemical Industries, Ltd.) was applied by a spin coater and then baked at 244 ° C. for 1 hour. Next, linearly polarized ultraviolet rays having an emission line spectrum near a wavelength of 254 nm were irradiated to the substrate surface by 0.5 j / cm ² at θ = 45 ° to obtain two substrates with alignment films. The substrate was coated with a thermosetting adhesive containing styrene beads having a diameter of 5.5 μm, leaving the liquid crystal injection port, dried at 80 ° C. for 5 minutes, and then the two substrates were in the presence of liquid crystal. The alignment film was placed on the inside so as to have a twist angle of 250 °, and pressure bonded, and the adhesive was cured at 150 ° C. for 90 minutes to obtain liquid crystal cell A.

  Further, about 0.98% of a chiral agent (S-811 manufactured by Merck & Co.) is added to the liquid crystal composition (I) having a negative dielectric anisotropy and Δn = 0.19 and K33 / K11 = 1.39. Thus, a liquid crystal material A was obtained.

  The liquid crystal cell A was filled with the liquid crystal material A by vacuum injection, and the liquid crystal injection port was sealed with an epoxy adhesive. Next, the lower polarizing plate was bonded to the lower substrate so that the incident direction of ultraviolet rays irradiated during the photo-alignment treatment of the lower substrate of the liquid crystal cell A and the angle of the absorption axis of the polarizing plate coincided. The upper polarizing plate was bonded to the upper substrate at an angle at which the absorption axes of the lower polarizing plate were orthogonal to each other, thereby producing a liquid crystal element A. At this time, d / p was 0.68.

As a result of measuring the electro-optical characteristics of the liquid crystal element A having the above configuration, the steepness γ was 1.035.
The pretilt angle of the liquid crystal element A was about 80.2 °.
Furthermore, when the light intensity in a state where there is nothing in the optical path (a state where only air exists) is 100%, the light transmittance when the liquid crystal element A when no voltage is applied is set in the optical path is 0.088 ( %)Met.
Note that the low light transmittance means that the liquid crystal element has little light leakage and high contrast.

(Example 2)
In this example, a liquid crystal element B was produced in the same manner as in Example 1 except that the baking temperature of the vertical alignment type alignment film solution was changed to 240 ° C. in Example 1.
As in Example 1, the electro-optical characteristics of the liquid crystal element B were measured, and as a result, the steepness γ was 1.11.
Further, the pretilt angle of the liquid crystal element B was about 85.8 °.
Furthermore, as a result of evaluating the light transmittance in the same manner as in Example 1, the light transmittance of the liquid crystal element B was 0.029 (%).

(Example 3)
In this example, in the same manner as in Example 1, except that the firing temperature of the vertical alignment type alignment film solution was changed to 240 ° C. and the twist angle was set to 200 °, the liquid crystal element C Was made. At this time, d / p was 0.55.
As in Example 1, as a result of measuring the electro-optical characteristics of the liquid crystal element C, the steepness γ was 1.194.
The pretilt angle of the liquid crystal element C was about 85.8 °.
Furthermore, as a result of evaluating the light transmittance in the same manner as in Example 1, the light transmittance of the liquid crystal element C was 0.028 (%).

(Example 4)
In this example, in Example 1, the dielectric anisotropy is negative, the liquid crystal composition (II) having Δn = 0.186 and K33 / K11 = 1.25, a chiral agent (S-811 manufactured by Merck) Was added in the same manner as in Example 1 except that about 0.98% was added. At this time, d / p was 0.68.
As in Example 1, the electro-optical characteristics of the liquid crystal element D were measured, and as a result, the steepness γ was 1.14.
The pretilt angle of the liquid crystal element D was about 80.2 °.
Furthermore, as a result of evaluating the light transmittance in the same manner as in Example 1, the light transmittance of the liquid crystal element D was 0.092 (%).

(Comparative Example 1)
In this example, a liquid crystal element E was produced in the same manner as in Example 1, except that the firing temperature of the vertical alignment alignment film solution was changed to 246 ° C. in Example 1.
As in Example 1, as a result of measuring the electro-optical characteristics of the liquid crystal element E, the steepness γ was 1.038. However, the curves of the electro-optical characteristics at the time when the applied voltage was increased and when the voltage was decreased were different, and hysteresis occurred.
When using as a normal liquid crystal display, when hysteresis occurs, the transmittance obtained when an intermediate voltage A is applied from a state where a high voltage is applied, and the intermediate voltage A is applied from a state where a low voltage is applied Since the transmittance obtained at this time is different, the display should be different from the content that should be displayed, and an accurate display cannot be performed.
Further, the pretilt angle of the liquid crystal element E was about 77 °.
Furthermore, as a result of evaluating the light transmittance in the same manner as in Example 1, the light transmittance of the liquid crystal element E was 0.216 (%).
From the above results, it is clear that the liquid crystal element E has a larger light leakage when no voltage is applied than in the first to fourth embodiments.

(Comparative Example 2)
In this example, in Example 1, except that the firing temperature of the vertical alignment type alignment film solution was changed to 240 ° C., the light irradiation amount at the time of light irradiation was 0.2 j / cm ² , and the liquid crystal material D was used. A liquid crystal element F was produced in the same manner as in Example 1.
As in Example 1, the electro-optical characteristics of the liquid crystal element F were measured. As a result, the steepness γ was 1.2.
Further, the pretilt angle of the liquid crystal element F was about 86.2 °.
Furthermore, as a result of evaluating the light transmittance in the same manner as in Example 1, the light transmittance of the liquid crystal element F was 0.029 (%).

(Comparative Example 3)
In this example, in Example 1, the baking temperature of the vertical alignment type alignment film solution is changed to 240 ° C., the dielectric anisotropy is negative, and Δn = 0.198, K33 / K11 = 1.03 liquid crystal A liquid crystal device G was produced in the same manner as in Example 1 except that about 0.98% of a chiral agent (S-811 manufactured by Merck & Co., Inc.) was added to the composition (III). At this time, d / p was 0.68.
As in Example 1, as a result of measuring the electro-optical characteristics of the liquid crystal element G, the steepness γ was 1.229.
Further, the pretilt angle of the liquid crystal element G was about 84.1 °.
Furthermore, as a result of evaluating the light transmittance in the same manner as in Example 1, the light transmittance of the liquid crystal element G was 0.036 (%).

(Comparative Example 4)
In this example, about 0.64% of a chiral agent (S-811 manufactured by Merck & Co., Inc.) was added to the liquid crystal composition (I) to obtain a liquid crystal material H.
A liquid crystal element H was fabricated in the same manner as in Example 1 except that the alignment film was bonded to the inside so that the twist angle was 150 °, and the liquid crystal material H was used. At this time, d / p was 0.41.
As in Example 1, as a result of measuring the electro-optical characteristics of the liquid crystal element H, the steepness γ was 1.324.
Further, the pretilt angle of the liquid crystal element H was about 85.5 °.
Furthermore, as a result of evaluating the light transmittance in the same manner as in Example 1, the light transmittance of the liquid crystal element H was 0.027 (%).
Table 1 summarizes the results of the above-described Examples and Comparative Examples.

FIG. 2 is a graph showing the relationship between the tilt angle and the steepness γ for the liquid crystal element A and the liquid crystal element G. FIG. 3 is a graph showing the relationship between the twist angle and the steepness γ for the liquid crystal element A and the liquid crystal element G.
2 and 3 reveal the following points.
(1) In the liquid crystal element A satisfying the configuration of the present invention, the steepness γ should be 1.2 or less in a wide range of tilt angles (81 ° to 89 °) and twist angles (180 ° to 270 °). it can.
(2) On the other hand, in the liquid crystal element G that does not satisfy the configuration of the present invention, the steepness γ exceeds 1.2.
From the above results, it was found that according to the present invention, a vertical alignment type super twisted liquid crystal display element having high steepness (1.2 or less) and little hysteresis can be obtained.

  The vertical alignment type super twisted liquid crystal display element and the manufacturing method thereof according to the present invention have been described above. However, the present invention is not limited to this, and can be appropriately changed without departing from the spirit of the invention. is there.

  The vertical alignment type super-twisted liquid crystal display element according to the present invention has high steepness (less than 1.2) and little hysteresis, so that light leakage does not easily occur in black display when no voltage is applied, and contrast reduction is suppressed. This will contribute to the provision of high-definition and high-definition displays for monitors and televisions.

It is a figure explaining the method of forming a vertical alignment film by the photo-alignment method. It is a graph which shows the relationship between a tilt angle and steepness (gamma). It is a graph which shows the relationship between a twist angle and steepness (gamma).

Explanation of symbols

θ The angle at which the substrate is irradiated with linearly polarized ultraviolet light, and φ The angle between the plane of polarization of the linearly polarized light and the XY plane (substrate surface).

Claims (4)

An electrode and an alignment film are sequentially stacked on one surface of the base material, and the pair of substrates are arranged so that the alignment films face each other, and are provided so as to be sandwiched between the pair of substrates. A liquid crystal material having negative dielectric anisotropy,
Both of the pair of substrates have an alignment control ability to give a pretilt angle of 80 ° to 86 ° to the liquid crystal molecules constituting the liquid crystal material,
The liquid crystal material contains at least one chiral agent, a value obtained by dividing a bending elastic constant K33 by a spreading elastic constant K11 is 1.25 or more, and a twist angle defined by the alignment film is 180 ° or more. 280 ° or less,
A vertical alignment type super twisted liquid crystal display element characterized by the above.   2. The vertical alignment type super twist liquid crystal display element according to claim 1, wherein the twist angle is not less than 240 [deg.] And not more than 270 [deg.].   When a natural twist pitch of the liquid crystal material is defined as p and a distance between the pair of substrates is defined as d, a value obtained by dividing the d by the p is 0.55 or more and 0.75 or less. Item 2. The vertical alignment type super twisted liquid crystal display element according to Item 1. An electrode and an alignment film are sequentially stacked on one side of the base material, and a pair of substrates are arranged so that the alignment films face each other, and are sandwiched between the pair of substrates. A liquid crystal material having negative dielectric anisotropy,
Both of the pair of substrates have an alignment control ability to give a pretilt angle of 80 ° to 86 ° to the liquid crystal molecules constituting the liquid crystal material, and the liquid crystal material contains at least one chiral agent and is bent. A method of manufacturing a vertical alignment type super twist liquid crystal display element in which a value obtained by dividing the elastic constant K33 by the expansion elastic constant K11 is 1.25 or more and the twist angle defined by the alignment film is 180 ° or more and 280 ° or less Because
An optical alignment process is used as a method for generating the pretilt angle.

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