JPH02199428A - Light control laminated body - Google Patents

Abstract

PURPOSE:To obtain the light control laminated body which allows arbitrary control of the see-through property of a window and is stable over a long period of time by disposing a liquid crystal material layer between the respective transparent conductive film sides of 1st and 2nd transparent conductive substrates, which films consist mainly of an indium oxide and are disposed to face each other, thereby forming the laminated body. CONSTITUTION:The liquid crystal material layer is disposed on the transparent conductive film of the 1st transparent conductive substrate constituted by forming the crystalline transparent conductive film mainly consisting of the indium oxide on a transparent supporting substrate. Further, the 2nd transparent conductive substrate is disposed thereon in such a manner that the transparent conductive film side faces the liquid crystal material layer side. The transparent conductive film of the 2nd transparent conductive substrate is the crystalline transparent conductive film mainly consisting of the indium oxide like with the 1st transparent conductive substrate. Namely, the laminated body disposed with the transparent supporting substrate, the transparent conductive film, the liquid crystal material layer, the transparent conductive film and the transparent supporting substrate in this order is formed. The light control laminated body which allows the arbitrary control of the transmittance of light and is stable over a long period of time is thereby obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application] The present invention relates to a light control laminate. Liquid crystal materials can control the transmission of light by applying an electric field or heat, so they are used in things such as calculator display elements and television screens. In recent years, windows in buildings have become larger in area, so if the transparency of windows can be controlled arbitrarily, a wide range of applications for safety, livability, and other purposes are expected. However, the conventional liquid crystal material-containing devices developed for the above-mentioned applications are completely unsuitable for achieving the above-mentioned objectives.

The present inventors have conducted intensive research to obtain a structure using a liquid crystal material suitable for the above purpose, and have arrived at the present invention.

[Components of the invention The above objects are achieved by the invention as follows.

In other words, the present invention provides a first transparent conductive substrate in which a crystalline transparent conductive film mainly made of indium oxide is formed on a transparent support substrate, and a liquid crystal disposed on the transparent conductive film. This is a light control laminate including a material layer and a second transparent conductive substrate disposed on the material layer so that the transparent conductive film side faces the liquid crystal material layer side.

The present invention will be explained in detail below.

The transparent supporting substrate used in the first and second transparent conductive substrates of the present invention is a plate glass or a flexible transparent film.

The flexible transparent film is mainly composed of an organic polymer film, but the organic polymer compound is not particularly limited as long as it is a transparent organic polymer compound that has heat resistance. Normally, heat resistance is preferably 100
℃ or higher, particularly preferably 130℃ or higher,
For example, polyimide.

Including polyether sulfone, polysulfone, polyparabanic acid, polyhydrane 1, polyethylene terephthalate 1, polyethylene-2,6-natsutale dicarboxylene 1 to 1. Examples include polyester resins such as polydiallylphthalate and polycarbonate, polyolefin resins such as stretched rigid vinyl chloride, stretched polypropylene, and polyethylene, aromatic polyamides, and cellulose triacetate-1.

Of course, these can also be used as homopolymers and copolymers, alone or in blends.

The shape of the molded product of the organic polymer compound is not particularly limited, but it is usually preferable to have a sheet shape or a film shape, and among them, a film shape can be rolled up and can be continuously produced. Therefore, it is particularly preferable. Furthermore, when a film is used, the thickness of the film is preferably 6 to 500 μm, more preferably 12 to 12 μm.
5 μm is preferred.

Pigments may be added to these films or sheets to the extent that transparency is not impaired, or surface treatments such as sand matting may be applied.

Further, these films or sheets may be used alone or in a laminated manner.

Further, an intermediate layer may be formed on the film before forming the transparent conductive film in order to improve the adhesion with the transparent conductive film formed thereon. As the intermediate layer, a layer produced by hydrolysis of an organometallic compound such as an organosilicon compound, a dithane alkyl ester, or a zirconium alkyl ester is preferably used. The intermediate layer may have a multilayer structure.

After the intermediate layer is coated on the film, it is dried and cured by heating, ion bombardment, or radiation such as ultraviolet rays, β rays, and γ rays.

The intermediate layer may be coated using a known coating machine such as a doctor knife, bar coater, gravure roll coater, curtain coater, or knife coater, depending on the shape and properties of the transparent film and coating solution. A spray method, a dipping method, etc. are used.

The thickness of the intermediate layer is preferably 100 to 100 OA, particularly preferably 200 to 900 OA. If there are fewer than 100 people, no continuous layer is formed and there is no effect of improving adhesion. Moreover, if the number of people exceeds 1000, cracks and peeling may occur, which is not preferable.

The transparent conductive film used in the first transparent conductive substrate of the present invention is a crystalline film mainly made of indium oxide.

In addition, a crystalline transparent conductive film mainly composed of indium oxide is one in which the Xm diffraction pattern of the transparent conductive film exhibits the [222] peak of indium oxide, or the Xm diffraction pattern is centered around 2θ-32°. It exhibits the broad peak of , and the [222] peak of indium oxide at the same time, and preferably also exhibits the [400] peak or the [440] peak at the same time. [222], [
When the peaks of [400] and [440] are exhibited at the same time, resistance stability, durability, etc. are particularly excellent.

The method for forming a transparent conductive film having an X-ray diffraction pattern according to the present invention is not limited to vacuum evaporation, but may be any known PVD method such as sputtering or ion blasting. Preferred application examples are shown below.

■ First, a layer containing mainly amorphous indium lower oxide is formed by a conventionally known method such as vacuum evaporation, sputtering, or ion blating at a temperature of 100°C or less for the polymer molded product, and then oxygen 100 under atmosphere
It is converted into a crystalline transparent conductive film by heat treatment at a temperature of ~250°C.

(2) With the polymer molded product heated to 100 to 250° C., a crystalline transparent conductive film is formed by a conventionally known method such as vacuum evaporation, sputtering, or ion blating.

The point is to experimentally determine the conditions under which the X-ray diffraction pattern of the present invention can be obtained depending on the properties of the polymer molded product.

In the vacuum evaporation method, an alloy containing indium as a main component or a molded product containing indium oxide as a main component can be used. In the former method, reactive gas such as oxygen gas is introduced into a vacuum chamber to perform reactive vapor deposition. In the latter case, a trace amount of a reactive gas such as oxygen gas is introduced into the vacuum chamber, or vapor deposition is performed without introducing any gas.

As a heating means for the vapor deposition material, known methods such as a resistance heating method, a high frequency heating method, an electron beam heating method, etc. can be applied.

An electron beam heating method is preferable as a method for forming a film at high speed and without compositional deviation.

In the sputtering method, an alloy containing indium as a main component or a sintered body containing indium oxide as a main component can be used as a target. In the former, an inert gas such as argon and a reactive gas such as oxygen gas are introduced into a vacuum chamber to perform reactive sputtering. In the latter case, sputtering is performed using an inert gas such as argon alone or a mixture of an inert gas such as argon and a trace amount of a reactive gas such as oxygen gas. As the sputtering method, known methods such as direct current or high frequency bipolar sputtering, direct current or high frequency magnetron sputtering, and ion beam sputtering can be applied. Among these, the magnetron method is preferable because it causes less plasma impact on the substrate and allows high-speed film formation.

Further, in the ion blating method, an alloy containing indium as a main component or a molded product containing indium oxide as a main component can be used. In the former case, reactive ion blating is performed by introducing a reactive gas such as oxygen gas alone or a mixed gas of a reactive gas and an inert gas such as argon into the vacuum chamber. In the latter case, an inert gas such as argon alone or a mixture of an inert gas and a trace amount of a reactive gas such as oxygen gas is used.

Here, the ion blating method is a method of forming a film while ionizing part of the evaporated particles and/or introduced gas, and ionization methods include direct current, alternating current, high frequency,
There is a method of applying microwaves or the like. There is also a method that does not require the installation of an ionization electrode near the evaporation source or the introduction of gas.

The transparent conductive film used in the present invention is a film mainly containing indium oxide. The indium oxide layer is originally a transparent electrical insulator, but it becomes a semiconductor when (1) it contains trace amounts of impurities, (2) it is slightly oxygen deficient, etc. Preferred semiconductor metal oxides include, for example, indium oxide containing tin or fluorine as an impurity. Particularly preferably, tin oxide is 2N20wt%
It is a film of indium oxide containing

In order to obtain sufficient conductivity, the thickness of the transparent conductive film mainly made of indium oxide used in the present invention must be 3.
It is preferably 0 Å or more, and more preferably 50 Å or more. Further, in order to obtain a film with sufficiently high transparency, the thickness is preferably 500 Å or less, more preferably 400 Å or less.

The first transparent conductive substrate in the present invention is formed by forming the above-mentioned transparent conductive film on the above-mentioned transparent support substrate.

Further, in the transparent conductive substrate of the present invention, a protective layer may be laminated on a transparent conductive film made of, for example, indium oxide for the purpose of so-called surface protection to improve scratch resistance.

Kakaru protective layer and Shiteha, Ti 02, Sn 02
.

Transparent oxides such as Si 02 , Zr 02 , Zn 2 O, etc.

Nitride such as Si 3 N 4 and Ti 2 N, or acrylonitrile resin, styrene resin, acrylate resin.

Transparent organic compound polymer such as polyester resin or
Organometallic compounds such as organosilicon compounds, titanium alkyl esters, zirconium alkyl esters, etc. can be used.

The thickness of such a protective film can be set arbitrarily within a range that does not deteriorate the characteristics of the transparent conductive film.

Furthermore, the transparent conductive substrate of the present invention may have a structure in which transparent conductive films are laminated on both sides of an organic polymer film via an intermediate layer as necessary, or a transparent conductive film may be laminated on one side of the organic polymer film as necessary. In a structure in which a transparent conductive film is laminated via an intermediate layer, adhesiveness 2 is used to improve the surface hardness, optical properties, etc. of the surface opposite to the surface on which the transparent conductive film is laminated, to the extent that transparency is not impaired. , for example, a layer of the same type as the above-mentioned intermediate layer, an oxide layer, a nitride layer, or a sulfide layer.

A carbide layer or an organic layer may also be provided.

The liquid crystal of the liquid crystal material layer in the present invention may be of nematic type, cholesteric type, or smectic type.

Nematic types include poly(p-phenylene terephthalamide) and poly(p-benzamide).

Poly(p-phenylenebenzobisoxazole).

Polymer liquid crystals such as poly(p-phenylenebenzobisthiazole), or 4'-methoxybenzylidene-4'-
Examples include compounds such as butylaniline, 4-cyano-4'hexoxybiphenyl, cyanobiphenyl compounds, cyanophenylcyclohexane compounds, and cyanocyclohexylcyclohexane compounds.

These compounds are often used in combination in order to adjust driving characteristics, stability, etc. In addition, many products containing these mixtures are commercially available, and these can also be applied.

Cholesteric types include cholesteryl lylate, cholesteryl oleate, and cellulose.

Examples include cellulose derivatives, DNA, RNA, and polypeptides.

Examples of the smectic type include polyester.

The liquid crystal in the present invention is preferably a nematic liquid crystal with positive dielectric anisotropy.

In the liquid crystal material layer of the present invention, these liquid crystals can be used as they are, or can be incorporated into a solid substance such as a polymer compound. A method of incorporating the liquid crystal is to simply mix the polymer compound and the liquid crystal together with a solvent, etc., apply the mixture to a plastic film substrate equipped with electrodes, and then remove the solvent and place the polymer compound containing the liquid crystal on the substrate film. There are several methods, including a method of forming a film, a method of microcapsulating liquid crystal in advance and then mixing it with a polymer compound and a solvent, coating and drying, and a method of impregnating a porous polymer film with liquid crystal. selected. In this case, the thickness of the liquid crystal material layer is several μm to several hundred μm.
Although the film thickness can be arbitrarily selected within the range of , a film thickness of several tens of micrometers is preferable from the viewpoint of cost and transparency.

Among the above, liquid crystals are a few micrometers deep in solid materials such as polymer materials.
It is preferable that it be contained in a spherical shape with a size of . As is well known, when no voltage is applied to the electrodes in this state, the liquid crystal material layer scatters incident light because the liquid crystal is randomly aligned as a whole. Then, the electrode is given a predetermined value, for example, 50~
When a DC or AC voltage of 100 V is applied, the dielectric anisotropy of the liquid crystal causes the liquid crystal to align parallel to the electric field and transmit incident light without scattering. Due to this phenomenon, a light control film with a laminated structure can adjust the amount of light transmitted by turning the voltage on or off, and can be used as a light control window, light control curtain, etc.

The second transparent conductive substrate in the present invention is formed by forming a transparent conductive film on a transparent support substrate, similarly to the first transparent conductive substrate.

Here, the transparent support substrate is as described above. The transparent conductive film used in the second transparent conductive substrate is preferably the crystalline transparent conductive film mainly composed of indium oxide used in the first transparent conductive substrate; And/or it may be made of a metal oxide thin film.

Moreover, this can be a metal thin film alone, a metal oxide thin film alone, or a combination thereof.

More specifically, the following can be mentioned.

■ Single or alloy metal thin films such as gold, copper, silver, aluminum, palladium, etc.; ■ Metal oxide thin films such as indium oxide, tin Mide, etc.; ■ By combining the metal thin film (■) and the metal oxide thin film (■), To improve transparency in a certain wavelength range: Particularly typical of the structures mentioned in (1) above are Bi2O3/AU/Bf formed using, for example, vacuum evaporation, reactive evaporation, chemical coating method or sputtering method. 20
3. Zn S/A (1/Zn S.

King l 02 /A! + /Tf 02, S! 02
/ (AU and/or A(1)/S! 02, Zr
02 /AgCU /Zr 02 , In 203/A
(1-CU/In 203, T! 02/A(
+ -CLI /T! 02 is mentioned. Further, the metal oxide thin film may be formed on only one side of the metal thin film.

The thickness of these metal thin films and metal oxide thin films is usually in the range of tens to thousands of layers, depending on whether they are used only as driving electrodes for the liquid crystal material or whether they also have infrared reflective ability to serve as heat insulation. Film thickness is different.

In the case of (1) and (2) above, in which a metal thin film is used in the shell, the thickness of the film is usually about 50 to 100 if it functions only as a drive electrode, and about 100 to 200 if infrared reflective ability is also required.

In the case of only metal oxide (2), 150 to 300 people if it functions only as a drive electrode, and 0.2 to 300 people if it also has infrared reflectivity.
The average thickness is about 0.5 μm.

In case (2), the metal oxide only has a function related to light interference, so conductivity is not required and the film thickness is about 100 to 300 mm.

A metal thin film can exhibit conductivity and infrared reflection functions with a small thickness, and is suitable as an electrode material on the substrate film side. However, as the film thickness increases, the transparency decreases, so it is preferable to increase the transmittance by layering metal oxides, as shown in the example (2).

Furthermore, it is also possible to form one or more layers in which the metal layer is sandwiched between the metal oxides.

In the light control laminate of the present invention, the transparent support substrate, the transparent conductive film, and the liquid crystal material layer described above are
The transparent conductive film/liquid crystal material layer/transparent conductive film/transparent support substrate are arranged in this order.

The use of the light control laminate of the present invention has the following advantages.

The durability of the liquid crystal material layer in the light control laminate is improved, and it is possible to obtain a light control laminate that is stable over a long period of time.

This will be explained in more detail below with reference to Examples.

[Examples 1 to 3 and Comparative Example 1] Butanol, an organosilicon compound, was added to a 100 μm thick biaxially stretched polyethylene terephthalate film.

Isopropanol mixed alcohol solution (11 degrees 0.6
% by weight) using a bar coater and dried at 120° C. for 1 minute. The thin film after drying was 200 people.

The film was fixed to a substrate holder in a DC magnetron sputtering device, and the vacuum chamber was evacuated to a vacuum level of 1×10 −5 Torr. After that, Ar102 mixed gas (02
20%) into the premises, and the vacuum level was set to 1 x 1 O-2 Torr.
After maintaining the temperature at r, transparent conductive films of Examples 1 to 3 and Comparative Example 1 were produced by reactive sputtering using a target made of In 2 /Sn alloy (Sn 5% by weight) while changing the substrate temperature.

The crystallinity of the transparent conductive film was measured using an X-ray diffraction device (RO manufactured by Rigaku Denki).
Cu- was examined using α-rays using taflX).

The results are shown in Table 1.

The X-ray diffraction pattern of the transparent conductive film of the present invention exhibited a [222] peak of indium oxide.

On the other hand, the [222] peak of indium oxide was not present in the X-ray diffraction pattern of the transparent conductive film of Comparative Example 1.

Next, acrylic resin (Mitsubishi Rayon LR574) and liquid crystal (B D l
-1 company E-37> mixture (1: solid content)
After applying the methyl ethyl ketone solution of 1.5),
It was dried at 0° C. for 2 minutes to form a liquid crystal material layer with a thickness of 15 μm.

Thereafter, a light control laminate was created by bonding together the transparent conductive film surfaces of the first transparent conductive film and the same second transparent conductive film.

The light control laminate has a transmittance of 5% when no voltage is applied.

It exhibited excellent light control ability with a transmittance of 60% when voltage was applied.

In order to check the durability during voltage application, an AC voltage of 100 V was applied, and ON-OFF cycles were repeated at 1-second intervals. The results are shown in Table 1.

In the light control laminate using the transparent conductive film of the present invention, no change in transmittance was observed when voltage was applied. On the other hand, in the light control laminate using the transparent conductive film of Comparative Example 1, the transmittance gradually decreased and the durability was poor.

Table 1

Claims (2)

[Claims] (1) a first transparent conductive substrate formed by forming a crystalline transparent conductive film mainly made of indium oxide on a transparent support substrate; a liquid crystal material layer disposed on the transparent conductive film; A light control laminate comprising a second transparent conductive substrate disposed thereon so that the transparent conductive film side faces the liquid crystal material layer side. (2) The light control laminate according to claim 1, wherein the transparent conductive film in the second transparent conductive substrate is a crystalline transparent conductive film mainly composed of indium oxide.