JPS5824763B2 - Exiyososhi - 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 that an electric field is applied to a liquid crystal layer formed between two parallel substrates.
It is based on changes in the optical properties of liquid crystals that occur when an external field such as a magnetic field, ultrasound, or heat is applied, and these changes in optical properties are based on the specific characteristics of liquid crystals when no external field is applied. This occurs when the orientation (initial orientation) 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 DS.
(Dynamic scattering) method, DA
P (Deformation of Vertical
ly AlignedPhases) method, TN (Tw
isted nematic) method, PC (Phase
In any liquid crystal element, a specific orientation of the liquid crystal when no electric field is applied is required in principle or in terms of performance.

In particular, in DS type and DAP type liquid crystal elements, the former is used from the viewpoint of improving display contrast or light modulation efficiency, and the latter is used from the standpoint of principle, both of which are based on the molecular length of the nematic liquid crystal, which is called homeotropic alignment. Orientation is required so that the axis is perpendicular to the plane of the substrate of the liquid crystal cell.

Several methods for homeotropic alignment of liquid crystals have been announced, and a representative one is t.
For example, there are methods of treating the substrate surface with an acid or alkali, and methods of treating the substrate surface with a certain type of surfactant or organic silane compound, but all of them have some drawbacks.
This cannot be said to be a practical liquid crystal alignment method.

In other words, it cannot be applied to a substrate on which an acid or alkaline earth metal vapor-deposited film electrode has been applied, and treatments using surfactants or organic silane compounds cannot achieve stable, durable, and reliable orientation. It's impossible.

The present invention solves the above-mentioned drawbacks and provides a substrate treated with the p-substituted chromium benzoate complex compound,
A glass plate, a metal plate, a Nesa glass plate coated with tin oxide, indium oxide, etc. on a glass plate, a metal plate coated with aluminum, chromium, gold, etc. It can be applied to any substrate surface, such as a vapor-deposited glass plate, and it is relatively easy to achieve uniform orientation over a large area of the substrate surface. Moreover, once achieved, the liquid crystal orientation is extremely stable and permanent. The purpose is to provide a liquid crystal element with excellent durability and reliability.

This embodiment will be explained in detail below. Figure 1 shows the cross-sectional structure of a liquid crystal element according to the present invention, in which two substrates 1°2, at least one of which is transparent, are arranged in parallel. , a spacer 3 is inserted to hold the substrates 1 and 2 at a predetermined distance, and the outer periphery is fixed with an adhesive 4.
Liquid crystal is filled through an injection hole 5 provided on one substrate, and an alignment imparting layer 7 is formed on the substrate surface in contact with the liquid crystal 6 by a coupling treatment of a p-substituted chromium benzoate complex compound.
, 7 are applied.

This alignment imparting layer 7 provides homeotropic (homeotropic) properties for nematic liquid crystals and smectic liquid crystals.
p ic ) orientation is imparted, and a focal cholesteric liquid crystal is imparted with a focalconic (focalconic) alignment or a homeotropic alignment.

The p-substituted benzoic acid chromium complex compound referred to in the present invention has a general structural formula (wherein, Y is alkyl, alkoxy, (Z is at least one of alkyl and alkoxy), and X is an anion. It is.

].

Specifically, for example, p-methylbenzoic acid, p-ethylbenzoic acid, p-n-butylbenzoic acid, p-methoxybenzoic acid, p-ethoxybenzoic acid, p-1-butoxybenzoic acid, p-isopropylbenzoic acid. Acid/pt-butylbenzoic acid, p-t-aluminumbenzoic acid, p-(N-(p'-methylbenziritin)amine]benzoic acid, p-L N
-(p'-ethylbenzilitine)amino]benzoic acid, p
-L N -(p'-methoxybenziritin)amine]benzoic acid, p-(N-(p'-ethoxybensyritene)amine]benzoic acid, p-(p'-methylphenylazo)benzoic acid, p- (p'-ethylphenylazo)benzoic acid, p-< p/-methoxyphenylazo)benzoic acid,
p −< p/-methylphenylazoxy)benzoic acid,
p-(p'-methoxyphenylazoxy)benzoic acid, p
-(p'-methylphenyl)benzoic acid, p-'-<p'
-ethylphenyl)benzoic acid, p-methylbenzoic acid-p
/ Carboxyphenyl ester, p-ethylbenzoic acid-p'-carboxyphenyl ester.

-n-furbenzoic acid-p'-carboxyphenyl ester, p-methyl-p'-carboxy-trans-
stilbene p-ethyl-p'-carboxy-trans
-Stilbenep-n-amyl-p'-carboxy-t
Examples include chromium complex compounds such as rans-stilbene, but of course the compound is not limited to these.

Furthermore, two or more of the above chromium complex compounds may be used in combination, if necessary.

In order to couple this p-substituted benzoic acid chromium complex compound onto a substrate, the chromium complex compound is used.

0.01 to 10% by weight of the substance with water or a suitable organic solvent
This solution is applied as a treatment liquid by a known method such as dipping, spraying, brushing, spinner method, pulling method, roll method, etc., and is dried to form a chromium complex/compound on the substrate. coupling and self-crosslinking of this chromium complex compound, and the alignment imparting layer 1 can be formed extremely easily and uniformly.

Similarly, if necessary, the pH of the treatment liquid may be adjusted by adding an alkaline substance such as ammonia, caustic soda, hexamethylenetetramine, or urea to neutralize the acidity, but the effect will not change.

A sufficient coupling effect can be obtained by drying the applied treatment solution only by natural drying at room temperature, but if necessary, heating and drying can form the S orientation imparting layer in a short time.

Furthermore, in order to maximize the substrate processing effect of the chromium complex compound, it is desirable to wash the coupling-treated substrate with water or a suitable organic solvent.

However, if two washings are 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, p7F-N< p
/-methoxybenzylidene)amine)-n-3butylbenzene (hereinafter abbreviated as MBBA), p-[N-(p
'-ethoxybenzylidene) aminocou-1-butylbenzene (hereinafter abbreviated as EBBA), p-1,N-(p'
-methoxybenziritin)amine] phenyv-jf rate, n-7 thiru p-(p-nioh 3 toxyphenokicarbonyl) phenyl carbonate, p-methoxy-p/
-〇-Methylazoxybenzene, p-ethoxy-p'-
〇Butyl azoxybenzene etc. are included.

Cholesteric liquid crystals include 4 cholesteryl chloride, cholesteryl nonanoate, cholesteryl oleate, cholesteryl-2-ethyl hequinanoate, cholesteryl benzoate, cholesteryl acetate, and smectic liquid crystals include N-(p-cyanobenzylidene)-p'-n-octyl. Aniline, Ly-p-abxybenzoate, ammonium oleate, and the like.

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

Next, a specific example of the present invention will be described using a liquid crystal element.

Example 1 The liquid crystal element shown in this example has a vertical dimension of 40 mm and a horizontal dimension of 80 mm.
The substrates each having a thickness of 1.5 mm are arranged in parallel, and a liquid crystal is sealed between the two substrates.

The substrate used here is the first to compare its effects.
■A simple glass plate whose surface that comes in contact with the liquid crystal is glass; ■A Nesa glass plate whose surface that comes into contact with the liquid crystal is coated with a transparent conductive film of tin oxide to act as an electrode plate; ■As a gold-layer reflective electrode plate. In order to operate, we tested four different combinations: an aluminum vapor-deposited glass plate with aluminum vapor-deposited on the surface that comes into contact with the liquid crystal, and a chrome metal plate whose surface that comes into contact with the liquid crystal is mirror-polished.

These substrates were prepared by adding water to the p-methoxybenzoic acid chromium complex compound solution to give 10% by weight, 1% by weight, and 0.1% by weight, respectively.
One coat was applied by dipping for 10 minutes in three types of treatment solutions expressed as % by weight.

After dip coating, drying treatment was performed by heating in an atmosphere of 150°C for 1 hour to complete the coupling between the p-methoxybenzoic acid chromium complex compound and the substrate as well as the self-crosslinking of the p-methoxybenzoic acid chromium complex compound. 1 piece.

After thoroughly washing each of the obtained substrates with running water, they were made into four types of combinations: glass plates and glass plates, Nesa glass plates and Nesa glass plates, Nesa glass plates and aluminum vapor-deposited glass plates, and Nesa glass plates and chrome metal plates, and parallel to each other. 12μ to provide space between the substrates for sealing the liquid crystal.
Fuse the mylar spacer and the board! The nylon adhesive sheet for sealing is held in a predetermined position and heated in an atmosphere at a temperature of 140° C. for 10 minutes while applying uniform pressure to fuse, thereby completing the structure of the liquid crystal element.

This structure was provided with an injection hole through which liquid crystal could be injected, and MBBA was injected and sealed through the injection hole to produce a liquid crystal element.

For each liquid crystal element obtained in this way,
As a result of observing the orientation of MBBA, excellent homeotropic orientation was shown in all cases.0 The homeotropic orientation was confirmed using a polarizing microscope between orthogonal nicols.

In other words, this was confirmed by observing the extinction phenomenon using an Orfscope and observing the dark cross belt (isogyre) using a Conoscope.

In addition, two types of liquid crystal element structures were prepared: a Nesa glass plate treated with an aqueous solution of the chromium complex compound having a concentration of 1% by weight, and one using the Nesa glass plate as a substrate, and one using a Nesa glass plate and an aluminum vapor-deposited glass plate as the substrates. Nematic liquid crystal (
Two liquid crystal elements injected with a mixed liquid crystal mixture of MBBA) 1/2 and (EBBA) 1/2 are used in DS method and DA method.
A P-type display operation test was conducted.

As a result, good display characteristics were maintained even after 6000 hours of continuous energization, and the hom-eotropic orientation of the enclosed liquid crystal was not impaired in any way.

[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. Curve/Adhesive, 5... Injection hole, 6...
-Liquid crystal, 7...Orientation imparting layer.

Claims (1)

[Claims] 1 General structural formula % Formula %] (Provided that Z is at least one of alkyl and alkoxy) and X is an anion. A liquid crystal element comprising a substrate treated with a p-substituted benzoic acid chromium complex compound represented by the following formula and a liquid crystal brought into contact with the treated surface of the substrate.