JPS6126645B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid crystal element useful for various optical devices such as display devices and light modulation devices, and more specifically, to a liquid crystal element in which filled liquid crystal is oriented in a fixed direction with respect to the surface of a substrate. Regarding.

Generally, the operating principle of liquid crystal elements for optical devices is as follows:
It is based on the changes in the optical properties of liquid crystal that occur when an external field such as an electric field, magnetic field, ultrasound, or heat is applied to the liquid crystal layer formed between two parallel substrates. , this change in optical properties is
This occurs when the specific orientation (initial orientation) of the liquid crystal when no external field is applied is deformed or disturbed by the application of an external field. This situation will be described in more detail below with respect to liquid crystal elements in optical devices that use an electric field as an external field, so-called electro-optical devices, which are currently entering the stage of practical use.

The main methods of electro-optical devices using liquid crystal elements include the DS (Dynamic Scattering) method and the DAP method.
(Deformation of Vertically Aligned Phases)
Method, TN (Twisted Nematic) method, PC
(Phase Change) method, etc., and in each method of liquid crystal elements, a specific orientation of the liquid crystal when no electric field is applied is required either in principle or in terms of performance.

Such alignment of liquid crystals is achieved, for example, by polishing the substrate surface with a wire cloth or abrasive, or by treating the substrate surface with a certain type of surfactant or organic silane compound. However, each case has some drawbacks and cannot be said to be a practical liquid crystal alignment.
In other words, with polishing methods, it is extremely difficult to achieve uniform orientation over a relatively large area of the substrate surface, and with treatments using surfactants or organic silane compounds, it is difficult to achieve permanence, durability, or reliability. A stable and stable orientation is not possible.

The present invention eliminates the above-mentioned drawbacks, and includes a substrate treated with a carboxylic acid polynuclear metal complex of a hetero macrocyclic compound or its derivative, generally referred to as a crown, and a substrate that is inserted in contact with the treated surface of the substrate. Substrates such as glass plates, metal plates, Nesa glass plates with tin oxide, indium oxide, etc. applied on glass plates, and metal-deposited glass plates with aluminum, chromium, gold, etc. deposited on them. It can also be applied to surfaces, and it is relatively easy to achieve uniform alignment over a large area of the substrate surface.Moreover, once achieved, the liquid crystal alignment is extremely stable, durable, and highly reliable. The purpose of the present invention is to provide a liquid crystal device with improved characteristics.

This example will be explained in detail below.
The figure shows a cross-sectional structure of a liquid crystal element according to the present invention, in which two substrates 1 and 2, at least one of which is transparent, are arranged in parallel, and the substrates 1 and 2 are held at a predetermined interval. A spacer 3 is inserted and the outer periphery is fixed with adhesive 4. Then, liquid crystal is filled through the injection hole 5 provided on one of the substrates, and on the surface of the substrate in contact with the liquid crystal 6, a compound is formed by coupling a carboxylic acid polynuclear metal complex of a hetero macrocyclic compound or its derivative, collectively called a crown. It has a structure in which an orientation imparting layer 7 is applied. In the liquid crystal element according to the present invention, the alignment imparting layer 7 imparts homeotropic alignment to, for example, a nematic liquid crystal.
On the other hand, cholesteric liquid crystals are given a focalconic or homeotropic orientation, and smectic liquid crystals are given a homeotropic orientation. By polishing the surface of the orientation imparting layer 7 in a certain direction, homogeneous orientation of nematic liquid crystal, smectic liquid crystal, etc. is imparted. Therefore, the liquid crystal element in which the liquid crystal is oriented according to the present invention is useful as a liquid crystal element based on the DS system, DAP system, PC system, NT system, etc.

In the present invention, the heteromacrocyclic compound generally referred to as crown or the carboxylic acid derivative thereof is represented by the general formula R(COOH)n -(1).

(Here, R is a heteromacrocyclic compound collectively referred to as a crown or a derivative thereof, and n is an integer.) As a specific example, (a) R is Carboxylic acid (b) R of a hetero macrocyclic compound consisting of C and O such as Carboxylic acid (c) of a hetero macrocyclic compound containing N such as Examples include carboxylic acids of S-containing hetero macrocyclic compounds such as. Examples of derivatives thereof include those having substituents such as amino groups, nitro groups, halogen groups, cyano groups, phenyl alkyl groups, compounds having crown groups as substituents, and polymers having crowns. , of course, it is not limited to these. In addition, in the carboxylic acid of these compounds, the carboxyl group is bonded directly to the crown ring, compound is bonded via a substituent, and compound is bonded to a compound having a crown as a substituent. , a compound that is bonded to a part of a polymer having a crown, and there is no difference in either bonding mode.

In the above structural formula, the symbol ● represents a CH ₂ group.

The carboxylic acid polynuclear metal complex of the crown compound or its derivative referred to in the present invention is, for example, a basic metal salt obtained by reacting a metal salt with an equimolar amount of alkali, and a carboxylic acid of the crown compound or its derivative. It can be easily obtained by blending and reacting at a ratio of 2 metal atoms per group.

The crown compound carboxylic acid polynuclear metal complex referred to in the present invention is, for example, when n is 1 in formula (1) When n is 2 in formula (1) (However, here, M is a metal atom, R is a hetero macrocyclic compound or a derivative thereof collectively referred to as a crown, X is an anion, and n is an integer.) Of course, the number of carboxyl groups is not limited, and there may be three or more.

Further, the above-mentioned metal atoms may be those having a coordination number of 4 or more, such as Cr, Fe,
Co, Ni, Al, Mn, Ti, Zr, Sn, Pb, Pt, Cu,
Examples include Zn, Pd, and lanthanide group elements.

In order to couple the crown compound carboxylic acid polynuclear metal complex according to the present invention onto a substrate, the metal complex is mixed with water or an appropriate organic solvent,
By forming a solution of 0.01 to 10% by weight and applying this solution as a treatment liquid by a known method such as a dipping method, a spray method, a brushing method, a spinner method, a pulling method, a roll method, etc., and drying. Coupling of the substrate and the metal complex and self-crosslinking of the metal complex are achieved, and the alignment imparting layer 7 can be formed extremely easily and uniformly.

If necessary, an alkaline substance such as ammonia, caustic soda, hexamethylenetetramine, or urea may be added to the above treatment solution to neutralize the acidity.
Even if you adjust the pH, the effect will not change.

Further, even if the applied treatment liquid is dried only by natural drying at room temperature, a sufficient coupling effect can be obtained, but if necessary, heating drying can be used to form the orientation imparting layer 7 in a short time.

Furthermore, in order to maximize the substrate processing effect of the metal complex, it is desirable to wash the coupling-treated substrate with water or a suitable organic solvent. However, if cleaning is not possible due to the substrate processing process or the structure of the liquid crystal element, it may be omitted.

The liquid crystal according to the present invention is not particularly limited, and any liquid crystal can be used.

For example, as a nematic liquid crystal, p-[N-(p'-methoxybenzylidene)amino]-n-butylbenzene (hereinafter abbreviated as MBBA) p-[N-(p'-ethoxybenzylidene)amino]-n -Butylbenzene p-[N-(p'-methoxybenzylidene)amino]phenylbutyrate n-Butyl-p-(p'-ethoxyphenoxycarbonyl)phenyl carbonate p-methoxy-p'-n- Butylazoxybenzene p-ethoxy-p'-n-butylazoxybenzene p-[N-(p'-methoxybenzylidene)amino]benzonitrile (hereinafter abbreviated as BBCA) p-[N-(p'-hexyl benzylidene)amino]benzonitrile, p-n-heptyl-p'-cyanobiphenyl, p-n-hexyl-p'-cyanobiphenyl cholesteric liquid crystals include cholesteryl chloride, cholesteryl nonanoate, cholesteryl oleate, cholesteryl-2-ethyl Hexanoate, cholesteryl benzoate, cholesteryl acetate, smectic liquid crystals include N-(p-cyanobenzylidene)-p'-n-octylaniline, ethyl-p-azoxybenzoate, ammonium oleate, and the like.

Alternatively, it may be a mixture of the above liquid crystals.

Next, specific examples of the present invention will be described.

Example 1 The liquid crystal element shown in this example has a height of 40 mm and a width of 80 mm.
1.5 mm thick and 1.5 mm thick are arranged in parallel, and a liquid crystal is sealed between the two substrates.

In order to compare the functions and effects, the substrate used here was a simple glass plate with a glass surface in contact with the liquid crystal, and a transparent conductive film of tin oxide was placed on the surface in contact with the liquid crystal to act as an electrode plate. We also include combinations of each of the following four types: a Nesa glass plate with aluminum coating, an aluminum vapor-deposited glass plate with aluminum vapor-deposited on the surface in contact with the liquid crystal to operate as a metal reflective electrode plate, and a chrome metal plate with mirror-polished surface in contact with the liquid crystal. Ta. Each of these substrates was prepared by adding water to the bis(carboxycyclohexyl)-18-crown-6 chromium complex solution.
The coating was applied by dipping for 10 minutes in three types of treatment solutions containing 1% by weight, 1% by weight, and 0.1% by weight. After dip application, 150℃
Dry by heating for 1 hour in an atmosphere of
The coupling between the chromium complex compound and the substrate and the self-crosslinking of the chromium complex compound were performed to complete the coupling with the substrate. Further, this substrate was washed with running water and dried, and then the surface of the substrate was lightly abraded two to three times in a fixed direction with cotton cloth (gauze). Each of the obtained substrates consists of a glass plate, a glass plate,
In order to combine four types of Nesa glass plates and Nesa glass plates, Nesa glass plates and aluminized glass plates, and Nesa glass plates and chrome metal plates, arrange them so that the friction polishing directions are perpendicular, and further fuse the substrate with a 12μ Mylar spacer. Next, a nylon adhesive sheet for sealing was placed in a predetermined position and fused by uniformly applying pressure in an atmosphere at a temperature of 140°C for 10 minutes to form a liquid crystal element structure.

A mixed liquid crystal containing 80% by weight MBBA and 20% by weight BBCA was injected into it to complete the liquid crystal element.

The alignment of the liquid crystals in this liquid crystal element was confirmed to be excellent twisted alignment by inspecting the uniformity of color tone using a polarizing microscope, as well as cross nicol,
This was confirmed by bright field and dark field examinations between parallel Nicols.

As a result of performing TN display operation tests on these liquid crystal elements, all of them were continuously energized at 5V AC and 50Hz.
It maintains good display characteristics even after 10,000 hours, and the twist orientation is not impaired at all, demonstrating excellent permanence, durability, and stability.

The same results as above were also observed when a bis(carboxycyclohexyl)-18-crown-6 aluminum complex compound was used instead of the bis(carboxycyclohexyl)-18-crown-6 chromium complex compound.

In addition, the carboxylic acid polynuclear metal complex of the present invention is
It has the effect of trapping alkali metal ions contained in the glass substrate, and even without providing a separate alkali blocking layer between the glass substrate and the alignment treatment film, a liquid crystal element with a long life without deteriorating the alignment of the liquid crystal can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway sectional view showing an embodiment of a liquid crystal element according to the present invention. 1, 2...Substrate, 3...Spacer, 4...Adhesive.

Claims (1)

[Claims] 1. It is characterized by consisting of a substrate whose surface including an electrode is treated with a carboxylic acid polynuclear metal complex of a hetero macrocyclic compound or a derivative thereof collectively referred to as a crown, and a liquid crystal which is inserted in contact with the treated surface of this substrate. liquid crystal element.