JPH01309025A - Liquid crystal-utilizing device - Google Patents

Abstract

PURPOSE:To form easily gaps between electrodes to a uniform thickness and to enable to provide a liquid crystal-utilizing device having a large area and a curved surface by using a specified film contg. liquid crystals dispersed therein in place of a liquid crystal layer. CONSTITUTION:A film contg. liquid crystals dispersed therein so as to construct a spongy structure with a matrix material is used as liquid crystal layer of a liquid crystal-utilizing device. Concrete examples for the matrix material are such as polyvinyl chloride resin, polycarbonate resin, polymethacrylate resin, polyvinyl acetate resin, hydrolyzed product thereof, synthetic or natural rubber such as SBR rubber, butadiene rubber, thermosetting resin such as unsatd. polyester resin, polyurethane resin. Thus, a liquid crystal utilizing-device having high reliability and flexibility, being capable of providing a large area, is obtd. easily and inexpensively.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to devices using liquid crystals.

[Background Art/Problems to be Solved by the Invention] Devices using liquid crystals are used not only as information display devices but also as filters that freely adjust the amount of light.

These devices hold fluid liquid crystals within an extremely narrow gap of several to several tens of rho and have a uniform thickness.
Since the liquid crystal layer is driven by applying a voltage to it, it is necessary to make the liquid crystal layer uniform in thickness. is necessary.

However, in order to manufacture a large-area device using liquid crystal using this method, it is necessary to form a gap with a uniform thickness over a large area, which is not easy to achieve.

Particularly in cases such as liquid crystal display devices, where it is not only necessary to simply change the orientation of the liquid crystal, but also to accurately display the desired object after changing the orientation of the liquid crystal, it is not easy to do so. do not have.

Furthermore, since glass is used, it is heavy, but also weak in strength, which is one of the reasons for hindering the wide range of applications of devices using liquid crystals.

In order to solve these drawbacks, a method has been proposed in which a liquid crystal encapsulated in a capsule is used in a capsule medium (Japanese Patent Application Laid-Open No. 62-48789).
However, the disadvantages include that the optical characteristics are affected by variations in the diameter of the capsule, and that the driving voltage becomes high.

[Means for Solving the Problems] The present invention improves the drawbacks in configuring the above-mentioned device using a large-area liquid crystal, and provides a device using a liquid crystal that can be easily and inexpensively made into a large-area device with high reliability and has flexibility. This invention relates to a device using a liquid crystal, characterized in that a liquid crystal dispersion film in which a matrix material is dispersed to form a sponge-like structure is used as the liquid crystal layer of the device.

[Example] In the present invention, a matrix material film in which liquid crystals are dispersed (hereinafter also referred to as a liquid crystal dispersion film) is used in place of the liquid crystal layer of devices using liquid crystals such as liquid crystal display devices and light amount adjustment filters.

Specific examples of the matrix material constituting the liquid crystal dispersion film include vinyl chloride resin, carbonate resin, methacrylate resin, vinyl acetate resin,
Hydrolyzed products thereof, thermoplastic resins such as cellulose resins, linear polyester resins, styrene resins, amide resins, nitrile resins, acetal resins, SBR rubber, butadiene rubber, butylene rubber, isoprene rubber, etc. Rubber, synthetic rubber such as acrylic rubber, nitrile rubber, urethane rubber, fluorine rubber, chloroprene rubber, silicone rubber, natural rubber, unsaturated polyester resin, urethane resin, urea resin, melamine resin, phenolic resin Examples include, but are not limited to, curable resins such as epoxy resins, alkyd resins, and crosslinked thermoplastic resins.

Since these matrix materials are used as a matrix for optical films, 50% or even 80%
It is preferable to have a light transmittance of the above value. Further, it is preferable that the refractive index of the liquid crystal and the matrix material be close to each other, and it is recommended that the difference is 0.5 or less, preferably 0.3 or less.

These matrix materials may be used alone or in combination of two or more. Further, if necessary, a heat stabilizer, a light stabilizer, an antioxidant, a lubricant, a surfactant, a trace amount of an inorganic filler, etc. may be included.

The liquid crystal dispersed in the liquid crystal dispersion film is not particularly limited, and when mixed with a matrix material, the matrix material phase and the liquid crystal F exist as different phases, and these phases are mixed with each other. It can be used as long as it exists in a state in which it has a nematic alignment, cholesteric alignment, or smectic alignment at the operating temperature, and can be used as a liquid crystal for a device using a liquid crystal.

Specific examples of the liquid crystal include 4-methoxybenzylidene-4°-butylaniline (MI3BA), 4-methoxybenzylidene-4°-butylaniline (MI3BA), and
Ethoxybenzylidene-4'-butylaniline (EBB)
Chemical formula represented by A): (In the formula, n and m are positive integers, the same shall apply hereinafter) is an alkoxybenzylidene alkylaniline liquid crystal compound, 4-butylbenzylidene-4'-cyanoaniline, etc. Schiff base liquid crystals such as alkoxybenzylidene cyanoaniline liquid crystal compounds represented by the chemical formula: 4-pentyloxybenzylidene-4°-cyanoaniline, etc.; Butyl-4°
-Methoxyazoxybenzene, 4-hexyl-4-butoxyazoxybenzene, etc. Chemical formula: Azoxy liquid crystal compound represented by 4-pentyl-4
An azo liquid crystal compound represented by the chemical formula represented by °-methoxyazobenzene, etc., 4-octyloxy-
4-pentyloxyphenylbenzoate, 4-pentyl-4-methoxyphenylbenzoate, 4-hebutyl-4-cyanophenylbenzoate, 4-cyanobenzene-4-butylphenylbenzoate, 4-pentylbenzene-4-butylphenylbenzoate, etc. Phenylbenzoate liquid crystal compounds represented by 4-cyano-
4-pentylbiphenyl, 4-cyano-4-heptyloxybiphenyl, 4-cyano-4-n-propyl-p-
Biphenyl liquid crystal compounds represented by terphenyl, 4-cyano-4°-octylbiphenyl, 4-cyano-4°-octyloxybiphenyl, 4-hexyl-4
゛-Butylcyclohexylcarboxybenzoate, 4
Cyclohexylcarboxylic acid represented by -bentroxy-4'-pentylcyclohexylcarboxybenzoate, 4-cyano-4'-propylcyclohexylcarboxybenzoate, 4-cyanobenzene-4'-ethylcyclo, xylcarboxybenzoate, etc. Acid ester liquid crystal compound, 4-propyl-1-(4-cyanophenyl)cyclohexane, 4-pentyl-1-(4-cyanobiphenyl)cyclohexane, 4-propyl-1-(
Phenylcyclohexane- and biphenylcyclohexane-based liquid crystal compounds such as 4°-ethoxyphenyl)cyclohexane, 4-pentyl-1-(4°-ethylphenyl)cyclohexane, and 4-pentyl-1-(4
-cyanophenyl)-pyridine, 4-cyano-1-(4
phenylpyridine liquid crystal compounds represented by °-pentoxyphenyl)-pyridine, 4-butyl-1-(4
Phenyldioxane liquid crystal compounds, such as 4-ethyl-1-(4°-cyanophenyl) dioxane, etc.
-cyanocyclohexyl) cyclohexane, cyclohexylcyclohexane-based and cyclohexylcyclohexane ester-based liquid crystal compounds represented by 4-propyl-4'-propylcyclohexyl-cyclohexanoate, 4-propylcyclohexyl-4°- Examples include cyclohexylethane liquid crystal compounds represented by ethoxyphenylethane, 4-pentylcyclohexyl-4°-cyanophenylethane, and the like. These may be used alone or in combination of two or more.

Preferably 60% or more, more preferably 70% or more of the volume of the liquid crystal dispersed in the matrix material communicates with at least one of the front and back sides of the liquid crystal dispersion film, and the matrix material forms a sponge-like structure. The liquid crystal is dispersed in the gaps.

The sponge-like structure refers to a state in which the matrix material forms a continuous phase in the form of a network, while the liquid crystal exists in the voids (pores or independent voids) surrounded by the matrix material. It is preferable that all the voids are connected from the front to the back of the liquid crystal film, or to one side of the front and back, but some of the voids may be independent islands (capsule-like). It's okay if it's true. Usually, the ratio of liquid crystal in a film made of these matrix materials/liquid crystals is 10 to 95% (by weight, hereinafter the same), preferably 20 to 80%. If the ratio is less than 105, most of the liquid crystal will dissolve in the matrix material, or even if it is dispersed as a liquid crystal phase, it will often exist as independently dispersed particles, such as in the liquid crystal dispersion film used in the present invention. A film in which the matrix material has a spongy structure is difficult to obtain. On the other hand, if it exceeds 95%, it tends to be difficult to form a liquid crystal dispersion film, making it difficult to achieve the object of the present invention.

The thickness of liquid crystal dispersion film is usually 2 to 1000! and
It is preferably 5 to 100 times. The thickness is t o o o
, the drive voltage becomes high and the material cost also increases, and when the stay is less than 2 nights, the influence of thickness variations tends to become large.

The void area created in a film-like matrix material by dispersing liquid crystal (i.e., the liquid crystal area)
Although it includes some encapsulated parts, most of it is internally connected, so it is difficult to define its size, but for convenience, we will use the short axis of the pore as seen on the cut surface of the film. When the length of is defined as the average diameter, it is preferably 11,000 μm or less, and more preferably 5 to 100 μm. The preferable range of this average diameter also differs depending on the thickness of the liquid crystal dispersion film, and for boat fishing, it is preferable that the thinner the film thickness is, the smaller the average diameter is. The average diameter does not need to be a uniform size, and may have a wide distribution, or may have a plurality of distributions such as large, medium, and small diameters.

Such films are produced using a casting method or water surface development using a composition prepared by adding a solvent and various additives to adjust the viscosity and handling properties of the composition to a composition consisting of a matrix material and liquid crystal. It can be formed by a method such as a method, a doctor blade method, a roll coating method, a dipping method, a spray method, or an electrostatic coating method.

For example, in the case of a casting method, a film is formed by preparing a solution or dispersion of a matrix material using a solvent, and casting the liquid crystal dispersed or dissolved in this solution.

The solvent for dissolving the matrix substance is preferably one that has a high solubility for the substance used, but it is also preferable to select it appropriately depending on the type of liquid crystal.

In addition, in the case of a water surface spreading method, a liquid crystal dispersion film having a desired thickness can be formed by spreading a solution containing a matrix material and a liquid crystal on a non-solvent surface.

Examples of additives added to the composition comprising the matrix material and liquid crystal include azo, methine, and merocyanine additives that are added to enable color display.
Dichroic dyes such as anthraquinone; dopants added to widen the temperature range, lower drive voltage, and lower viscosity; liquid crystal; life-enhancing agents to improve the life of liquid crystal display elements;

The liquid crystal dispersion film may be produced as a single film, but since the required thickness of the film is preferably 5 to 100 mm, handling may be difficult. In such a case, it may be formed directly on an electrode of a protective substrate or on an alignment film that serves as a thin film electrode when manufacturing a device using a liquid crystal.

Furthermore, depending on the purpose, in order to control the initial alignment state of liquid crystal molecules in the liquid crystal dispersion film, a polymer film such as polyimide resin or polyvinyl alcohol may be formed on the surface of the glass or polymer film serving as the substrate, or lecithin, polyvinyl alcohol, etc. By depositing hexadecylamine, myristic acid complex, chromium complex, silane coupling agent, etc., various oxides,
Surface treatment by oblique evaporation of fluoride or metal or ion shower, grating by photo etching or replica, or mechanical alignment treatment by rubbing may be used in some cases.

When the liquid crystal dispersion film formed in this way is used in place of the liquid crystal layer of a device using liquid crystal, the adhesion area between the alignment film and the liquid crystal is smaller than when the liquid crystal is dispersed in islands in a polymer film. Since it is wider and the amount of liquid crystal used can be increased, it can be driven at a lower voltage. moreover,
Since the liquid crystal dispersion film used in the present invention has a constant thickness, it can be used as a display layer having a uniform thickness over a wide area without using a spacer, like conventional liquid crystal dispersion films.

Next, a liquid crystal device using the liquid crystal dispersion film used in the present invention will be explained.

The device using liquid crystal may be of any conventional type, such as DS type, TN type, Ge1 type, PC type, ECB type, etc.

Further, depending on the above method, it may be used in combination with a polarizing plate, a light reflecting/diffusing plate, etc., as in conventional liquid crystal devices. Further, various filters such as an ultraviolet cut filter, a color filter for color display, a surface antireflection filter, etc. can be used in combination depending on the purpose.

There is no particular restriction on the connection method between the liquid crystal device of the present invention and the driving electronic circuit, and any conventional connection method such as a pin connector, an elastic connector, or a flexible connector may be used.

When used as a transmissive liquid crystal element, an incandescent light bulb, a white halogen light bulb, a fluorescent lamp, an electroluminescent lamp, a light emitting diode, a plasma light emitting panel, etc. can be used as a backlighting light source.

A typical liquid crystal device consists of, for example, a transparent conductive film and a transparent substrate provided on one side of a liquid crystal layer, a transparent conductive film and a transparent substrate provided on the other side, or a thin film electrode and a substrate. Alternatively, an alignment film and/or an insulating film may be formed between the thin film electrode and the liquid crystal layer, and a polarizing plate or the like may be further attached.

The alignment film may be a commonly used plastic film made of polyester, polyamide, polyimide amide, polyvinyl alcohol, etc., rubbed by a conventional method, or a film made by diagonally depositing silica on a transparent substrate.

This alignment film has a great effect on the performance of devices using liquid crystals, and it is important to decide whether to provide it on both sides or one side of the liquid crystal dispersion film, whether to use the same or different materials for the front and back alignment films, and the direction of rubbing. It is preferable to select the appropriate method depending on the material of the alignment film, the liquid crystal used, the matrix material, the balance of these alignment materials, etc.
Although this cannot be said in general, - in the case of nematic alignment in the film, it is advantageous to provide the liquid crystal dispersion film with the same alignment direction on both sides, and in the case of smectic alignment, By changing the material of the alignment films on both sides of the film,
It tends to be better to rub on one side, but it is not limited to this.

In the liquid crystal device of the present invention, a film in which liquid crystal is dispersed in a matrix material in a specific state is used instead of the conventional liquid crystal layer. Therefore, when using a conventional liquid crystal layer, two substrates are required to hold it, and a spacer is required to hold the two substrates at a certain distance. Moreover, it is possible to replace devices using liquid crystals, which solves the problem that it is difficult to replace especially large-area display devices because the thickness tends to warp.

The liquid crystal device of the present invention can be suitably used for large-area display devices and dimming filters.

Next, the apparatus of the present invention will be explained based on examples.

Example I On a 100-thick polyester sheet on which ITO was formed, 40 parts of polyvinyl chloride (manufactured by Mitsui Toatsu Chemical Co., Ltd., Vinicron 4000M), 4-cyano-4°-pentylbiphenyl (manufactured by BD11 Co., Ltd., K) 15) 60 parts of a 40% solution of natrahydrofuran was applied and dried at 70° C. for 1 hour to form a liquid crystal dispersed film having a thickness of 10−. A polyester sheet with a thickness of 1'OO on which patterned ITO was formed on this laminate film was vacuum laminated with the ITO layer facing the liquid crystal dispersion film.
A press sheet measuring 100111 x 10 cm was produced.

The obtained device was cloudy as it was due to light scattering by the liquid crystal, but when a voltage of 80 V was applied between the two electrodes, only the area between the patterned electrodes became transparent and the pattern was displayed. Even when the device was wrapped around a cylindrical object with a radius of curvature of 10 cm and the voltage was applied, the same pattern was displayed.

Example 2 An apparatus similar to that of Example 1 was made using the polymer shown below in place of the polyvinyl chloride of Example 1, and when operated in the same manner, the same results were obtained.

(1) Polybutadiene rubber (manufactured by Japan Synthetic Rubber, J
SRBROI) (2) Styrene-butadiene copolymer rubber (manufactured by Japan Synthetic Rubber, JSI? SBI? 1502) (3)
Acrylonitrile-butadiene copolymer rubber (manufactured by Japan Synthetic Rubber ■, JSRN2208) (4) Ethylene-propylene copolymer rubber (manufactured by Nippon Synthetic Rubber ■, EP912)
P) (5) Isoprene-isobutylene copolymer rubber (manufactured by Nippon Gosei Rubber ■, Butyl 0Ei5) (6) Polyvinylidene fluoride (manufactured by Benwall I Co., Ltd., KYN
AR720) ('7) Epoxy resin (manufactured by Shell Chemical Co., Ltd.) (8)
Ethylene-vinyl acetate copolymer (manufactured by Mitsui DuPont Polychemical ■, #33) (9) Polyvinyl carbazole (manufactured by Kanto Chemical ■) [
10) Polyparaphenylene terephthalamide (manufactured by DuPont) al) Polymethyl methacrylate (Kanebuchi Chemical Industry ■
TA) OZ polycarbonate (manufactured by Idemitsu Kosan ■, 8-Example 3 A device similar to Example 1 was made using the liquid crystal compound shown below instead of 4-cyano-4-pentylbiphenyl in Example 1, When the same operation was performed, the same results as in Example 1 were obtained.

However, the test temperature was selected to be optimal for each liquid crystal compound.

(114-cyano-4-n-hebutoxybiphenyl (2
) 4-cyano-4-n-pentyl-p-terphenyl (3) 4-butyl-4-methoxyazoxybenzene (4
) 4-pentyl-4-methoxyazobenzene (5)
4-Hebutyl-4-cyanophenylbenzoate (6) 4-propyl-1-(4°-cyanophenyl)cyclohexane (7) 4-propyl-1-(4-ethoxyphenyl)cyclohexane (8) 4-cyano- 1-(4'-pen!xyphenyl)pyridine f9) 4-cyano-4-pentylthiophenylbenzoate 00) 4-cyano-4-ethylcyclohexylcyclohexane Example 4 and Comparative Example 1 Height: 500 squares, Width: 500 m11. 3 mtx thick ITO
A liquid crystal dispersion film with a thickness of 10 mm is formed on the float glass plate on which the layers have been formed in the same manner as in the example work, and the above float glass is laminated and integrated on top of this, and the film between the float glass plates is A conventional liquid crystal element (Comparative Example 1) was prepared by inserting a polyethylene terephthalate spacer with a width of 10 m + s around it and injecting only 4-cyano-4°-pentylbiphenyl inside the spacer. We compared the changes.

In Example 1, the cell thicknesses at the ends and the center were equal;
Transparency during voltage application was uniform over the entire area.

However, in Comparative Example 1, the cell thickness at the center was significantly reduced compared to the cell thickness at the ends, and bending of the upper glass plate was observed. Therefore, the transparency during voltage application was non-uniform with turbidity observed in the center.

In this way, a liquid crystal device using a liquid crystal dispersion film makes it possible to enlarge the area of a liquid crystal element.

[Effects of the Invention] In the liquid crystal device of the present invention, a specific liquid crystal dispersion film is used in place of the liquid crystal layer, so that it is possible to easily form and maintain an inter-electrode gap of uniform thickness. As a result, it is possible to manufacture a device using a liquid crystal that is large in area, lightweight, and can have a curved surface. Such a liquid crystal device has high moisture resistance and can be driven at a lower voltage than a liquid crystal device using a conventional liquid crystal dispersion film.

Patent applicant Chisato Kajiyama and 2 others

Claims (1)

[Scope of Claims] 1. A device using a liquid crystal, characterized in that a liquid crystal dispersion film in which a matrix material disperses liquid crystal in a sponge-like manner is used as a liquid crystal layer of the device using a liquid crystal. 2. The device according to claim 1, wherein most of the liquid crystal in the liquid crystal dispersion film is in communication from the front to the back of the film. 3. Claim 1, wherein the matrix material is a rubber-like elastic material.
The device described. 4. The device of claim 1, wherein the matrix material is a thermoplastic resin. 5. The device of claim 1, wherein the matrix material is a curable resin.