JPH0416925A - Liquid crystal element and its manufacture - Google Patents

Abstract

PURPOSE:To obtain a liquid crystal element with superior orientation property by forming an orientation layer consisting of solid organic molecules oriented on at least the main plane of a first substrate or second substrate, and sandwiching a liquid crystal layer between the first and second substrates. CONSTITUTION:This element is comprised of the first and second substrates 1, 2 made of transparent glass, etc., rectangular transparent conductive electrodes 3, 4 consisting of ITO film, etc., provided on the main planes of the first substrate 1 and the second substrate 2, orientation film 5, 6 consisting of an oriented solid organic molecule, and the liquid crystal layer 7. A ferroelectric liquid crystal component, a P-type nematic liquid crystal component, or an N-type nematic liquid crystal component is sandwiched between the first substrate 1 and the second substrate 2. Thereby, the liquid crystal element with superior orientation property can be obtained.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a liquid crystal element and a method for manufacturing the same.

2. Description of the Related Art An alignment film for aligning liquid crystal molecules in a certain direction is essential in the field of liquid crystal display technology.

Conventionally, alignment films include obliquely deposited films made of inorganic materials,
A polymer resin film or the like that is rubbed in a certain direction with cloth or the like is used. Polyimide is mainly used as the material for the polymer resin film.

Problems to be Solved by the Invention However, the above-mentioned conventional method for manufacturing an obliquely deposited film in a liquid crystal element requires too much production cost, and is not a practical method.

Here, the problems caused by a polymer resin film that has been rubbed with cloth or the like will be explained below.

First of all, there is the generation of dust and the like due to friction, which causes a decrease in production yield.

Second, when trying to achieve alignment of liquid crystal molecules with a high pretilt angle using a polymer resin film, there are many problems such as streaks appearing in the display of the liquid crystal element and poor reproducibility of the pretilt angle. These problems also occur in STN mode, homeo mode, and 5SFLC mode using ferroelectric liquid crystal.

The present invention solves the above problems, and aims to provide a liquid crystal element having excellent alignment properties.

Means for Solving the Problems In order to achieve the above object, the present invention forms an alignment layer made of solid organic molecules oriented on at least the main surface of the first substrate or the second substrate, and A ferroelectric liquid crystal composition, a P-type nematic liquid crystal composition, or an N-type nematic liquid crystal composition is sandwiched between substrates.

The present invention also provides for forming an alignment layer made of oriented solid organic molecules on at least the main surface of the first substrate or the second substrate, further forming a vertical alignment side layer thereon, and forming an alignment layer on the main surface of the first substrate or the second substrate. It is made by sandwiching a ferroelectric liquid crystal composition or an N-type nematic crystal composition.

It is desirable that the solid organic molecule has a liquid crystal state in an f4 solution, that is, a lyotropic liquid crystal state.

The method for manufacturing a liquid crystal element of the present invention involves coating a substrate with a solution exhibiting a liquid crystal state containing 78 solid organic molecules, and simultaneously applying a DC magnetic field of a predetermined intensity in a predetermined direction while removing the solvent from the solution. This process consists of forming an alignment layer made of solid organic molecules by removing the solid organic molecules.

Therefore, according to the present invention, a lyotropic liquid crystal solution is prepared by dissolving solid organic molecules in a suitable solvent (usually preferably a concentrated solution), and this is applied onto a substrate, and at the same time, a predetermined amount of liquid crystal is applied. When a DC magnetic field of a predetermined strength is applied in the direction and the solvent is directly removed from the solution, an alignment layer made of oriented solid organic molecules is obtained. X-ray diffraction revealed that this orientation layer was oriented in accordance with the direction of the magnetic field.

The present invention further provides that liquid crystal molecules (CP pear-shaped liquid crystal composition, N-type nemati liquid crystal composition, ferroelectric liquid crystal composition, etc.) are aligned on the alignment layer made of solid organic molecules oriented in this manner. This stemmed from the discovery that Furthermore, it is necessary to appropriately set the strength and direction of the DC magnetic field, which has been insufficient in the past. It has been found that high reproducibility can be obtained in high pretilt liquid crystal molecular alignment.

Furthermore, when an alignment layer made of aligned solid organic molecules is formed on the substrate, a vertical alignment agent is further applied thereon, and a ferroelectric liquid crystal composition or an N-type nematic liquid crystal composition is sandwiched between the substrates, It has also been found that uniform orientation is possible. This layer of vertical alignment agent is preferably about 300 angstroms or less.

Example Embodiments of the present invention will be described below with reference to the drawings.

In FIGS. 1 and 2, 1 and 2 are a first substrate and a second substrate made of transparent glass, etc., and 3.4 is an ITO film etc. provided on the main surfaces of the substrate J and the second substrate 2. 56 is an alignment layer made of oriented solid organic molecules, 7 is a liquid crystal layer, and 8 and 9 are vertically aligned alignment films.

Example 1 On the main surfaces of the first substrate 11 and second substrate 2 made of transparent glass having conductive electrodes 3.4 made of ITO film, 1.1
．． 2=) Polygamma-hensylglutamate having a molecular weight of about 105 dissolved in dichloroethane was applied by dipping. Next, while applying a DC magnetic field of about 100 Gauss at an angle of about 30 degrees perpendicular to the substrate surface,
Solvent 1.1.2-1-lichloroethane is evaporated using hot air.

As a result of the X-ray diffraction experiment of the obtained alignment layer 5.6, polyT
It was found that the orientation layers 5 and 6 made of -hensil-monoglutamate were present, although the orientation was weak.

Next, the first substrate 1 and the second substrate 2 were bonded together to form a liquid crystal cell, and a liquid crystal composition was injected into the cell to form a liquid crystal layer 7, thereby obtaining a liquid crystal element. A UV curing resin was used as a sealing material for bonding the first substrate 1 and the second substrate 2 together. When an STN (super-wetted TN) liquid crystal composition was used as the liquid crystal composition, it was confirmed by measurement of optical properties, pretilt angle, etc. that the alignment was a uniform tilted alignment.

The display characteristics were also excellent, with no defects such as streaks. Furthermore, when a ferroelectric liquid crystal composition was used as the liquid crystal composition, stable uniform alignment was obtained and display characteristics were also excellent. However, in this case, the gap between the first substrate and the second substrate was approximately 2 microns.

Example 2 On the main surfaces of the first substrate 1 and the second substrate 2 having conductive electrodes 3.4 made of ITO films, alignment layers 5 and 6 made of oriented poly-T-benzyl-monoglutamate were formed. . However, the direction of the applied magnetic field was about 5 degrees perpendicular to the substrate surface. Next, use Merck's vertical alignment agent zL■-
3124 was applied by high-speed centrifugation and dried to provide a vertically aligned alignment film 8.9, and then the first substrate 1 and the second substrate 2 were bonded together in the same manner as in the example to form a liquid crystal cell.
The inside thereof was filled with N-type nematic liquid crystal to form a liquid crystal layer 7, and a liquid crystal element was obtained. The effect was the same as in Example 1, and the alignment of liquid crystal molecules was uniform, there were no defects such as streaks in display characteristics, and a liquid crystal element with excellent image quality and reliability could be obtained.

As described above, according to the above embodiment, it is possible to increase the production yield without contaminating dust in the alignment process, and to achieve alignment with a high pretilt angle of liquid crystal molecules, thereby eliminating defects such as streaks in the display. Therefore, a liquid crystal element with excellent pretilt angle reproducibility can be obtained.

Note that in the above embodiment, the alignment layers 5 and 6 are formed on the first substrate 1.
Although the description has been made of the case where the substrate is provided on both the first substrate 1 and the second substrate 2, the object of the present invention can be achieved even if the substrate is provided on either the first substrate 1 or the second substrate 2.

Effects of the Invention As is clear from the above embodiments, the present invention forms an alignment layer made of oriented solid organic molecules on the soil surface of at least a first substrate or a second substrate, and A liquid crystal layer is sandwiched between the liquid crystal layers, and it is possible to obtain a liquid crystal element with excellent alignment properties, and also to provide an extremely rational and highly productive method for manufacturing liquid crystal elements without the generation or contamination of dust. be.

[Brief explanation of drawings]

FIG. 1 is a partial sectional view of a liquid crystal element in a first embodiment of the invention, and FIG. 2 is a partial sectional view of a liquid crystal element in a second embodiment of the invention. l...first substrate, 2...second substrate, 5
．． 6...Alignment layer, 7...Liquid crystal layer, 8.
9... Vertical alignment alignment film.

Claims (4)

[Claims] (1) Forming an alignment layer made of oriented solid organic molecules on at least the main surface of the first substrate or the second substrate;
A liquid crystal element comprising a substrate and a second substrate sandwiching a liquid crystal layer made of a ferroelectric liquid crystal composition, a P-type nematic liquid crystal composition, or an N-type nematic liquid crystal composition. (2) forming an alignment layer made of oriented solid organic molecules on at least the main surface of the first substrate or the second substrate; further forming a vertical alignment agent layer thereon;
A liquid crystal element comprising a liquid crystal layer made of a ferroelectric liquid crystal composition or an N-type nematic liquid crystal composition sandwiched between substrates. (3) The liquid crystal element according to claim 1 or 2, wherein the solid organic molecule has a liquid crystal state in a solution containing the solid organic molecule as a solute. (4) applying a solution exhibiting a liquid crystal state with solid organic molecules as a solute on at least the main surface of the first substrate or the second substrate;
Claim (1) or (2), wherein the orientation layer made of the solid organic molecules is formed by removing the solvent from the solution while simultaneously applying a DC magnetic field of a predetermined strength in a predetermined direction.
) A method for manufacturing a liquid crystal element as described above.