JPH0643502A - Fully solid-state light control device and light control method using this device - Google Patents

Abstract

PURPOSE:To provide the fully solid-state light control device which can be easily produced to a large area by a method, such as screen printing, can control transmittance in multiple stages by using solid-state dispersion media without splashing in the event of leakage or failure of particulate dispersion media and by adjusting the shearing stress acting on the dispersion media and has the higher performance to control the transmittance by being provided with particulate adhesion preventive layers. CONSTITUTION:This light control device consists of a pair of substrates 1, 2 which are provided with the particulate adhesion preventive layers 2 on at least either of the inner sides of the substrates 1, 2 facing each other, viscoelastic bodies or elastic bodies 4 which contain the particulates or particulate assemblages 3 arranged in the specified direction with the substrates 1, 2 between the substrates 1 and 2 and the device for acting the shearing stress on the viscoelastic bodies or elastic bodies 4. This light control method acts the shearing stress on the viscoelastic bodies or elastic bodies 4 by using this fully solid-state light control device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an all-solid-state light control device and a light control method using the same. More specifically, the present invention relates to a novel all-solid-state light control device excellent in light transmittance control performance and a light control method using the same.

[0002]

2. Description of the Related Art In recent years, office buildings have become taller and windows have become larger, and at least 25% of the energy consumption in office buildings comes in or out of windows as light or heat. Therefore, from the viewpoint of effective use of energy, development of a large-area dimmer is desired. Also, with the increase in the number of passenger cars due to the rise of motorization, and in addition to the increase in the number of passenger cars becoming more sophisticated, coolers are now installed in almost all cars, and from the viewpoint of effective use of energy, passenger car windows, especially power consumption, are becoming severe. It is also desired to develop a dimmer suitable for windows of limited electric vehicles.

In order to meet such a demand, a dimmer for the purpose of reducing the cooling and heating load by electrically controlling the absorbance or reflectance of sunlight has been developed. Some electro-magnetic optical elements have also been studied for the purpose of application to a light control device.

As one of the dimming devices that have been conventionally studied, one using an electrochromic element (hereinafter referred to as an EC element) is known (CM Lampert, Solar Energy Material).
(Solar Energy Mater.), Volume 6, Issue 1 (1981)). The light control device using this EC element mainly utilizes the spectral change associated with the electrochemical redox reaction of the tungsten oxide film, that is, the large absorption or reflection of light in the visible-near infrared region of the tungsten bronze. It is a thing.

As another dimmer, a device using a suspension in which anisotropic dipole fine particles are dispersed in a liquid dielectric (hereinafter referred to as a DPS element) is known. This DPS element is basically a suspension of fine particles having a shape anisotropy, such as needles and plates, dispersed in a liquid dielectric, sandwiched between glass substrates with a transparent conductive film. The change in light transmittance due to the difference in the orientation of the dispersed fine particles depending on the presence or absence of is utilized. That is, when an electric field is applied, the fine particles are aligned with their long axes parallel to the electric field and are in a state in which light is well transmitted (open state). On the contrary, when the action of the electric field is released, the Brownian motion releases the restraint of the particles. This is utilized because it is in a disordered orientation and becomes a state where light does not pass (closed state). This change in state of the electro-magnetic optical device is called a switching action.

An electro-magnetic optical device using this DPS element was originally developed from the end of the 1960s for the purpose of application to a display element, and several patents relating to this have been filed (for example, US Pat. 3,257,903
(1966), JP-A-51-69038). As described above, this electro-optical device can be used as a light control device because the light transmittance changes under an electric field.

Although not a light control device, a multi-directional light control film in which main axes are arranged in parallel in a matrix has recently been proposed as a technique related to the present invention (Japanese Patent Laid-Open No. 3-30083).
31804 publication).

[0008]

However, in the light control device using the EC element, since the EC element is a current drive type, an IR drop occurs, and the response speed remarkably decreases when the area is increased. There is a problem. Also, EC
There is also a problem due to the operating principle that the device does not operate substantially at low temperatures.

These problems become a major obstacle when the electro-optical device using the EC element is used in a large area light control device.

On the other hand, the light control device using the DPS element has a large variation range of the light transmittance in the initial stage, and since it is of the electric field driving type, it is relatively easy to increase the area, and the EC element is used. There is no problem that the dimmer has. However, since this element normally disperses fine particles in a liquid, there is a problem that fine particles aggregate and settle, causing color unevenness in the vertical direction, a decrease in light transmittance change width, and deterioration of switching action. is there.

Further, the multi-directional light control film is one in which the arrangement of needles is completely fixed and has an antiglare function, but has a so-called light control function of arbitrarily controlling the light transmittance. I haven't.

[0012]

In view of the problems of the prior art, the present inventors have previously used a viscoelastic body or an elastic body as a fine particle dispersion medium to prevent aggregation and sedimentation of fine particles, and The light transmittance can be adjusted by changing the light transmittance by applying shear stress to the elastic body or the fine particles or fine particle aggregates arranged in a certain direction in the elastic body, and adjusting the stress at that time. We have proposed an all-solid-state dimming device and dimming method with excellent control performance (Japanese Patent Application No. 3-175567).

The inventors of the present invention then conducted further studies, and as a result, by providing a particle adhesion preventing layer inside the pair of substrates, an all-solid-state light control device having further excellent light transmittance control performance was obtained. The present invention has been completed and the present invention has been completed.

That is, according to the present invention, a pair of substrates each having a particulate adhesion preventing layer provided on at least one of the insides of opposing substrates, and a particulate or a particulate aggregate arranged between the substrates in a certain direction with respect to the substrate. An all-solid-state dimmer, characterized by comprising a viscoelastic body or an elastic body containing the same, and a device exerting a shear stress on the viscoelastic body or the elastic body, the viscoelastic body or elastic body of the all-solid-state dimmer The present invention relates to a dimming method characterized by exerting a shear stress with a device exerting a shear stress to control the light transmittance.

[0015]

Since the all-solid-state light control device of the present invention uses a viscoelastic body or an elastic body as a medium containing fine particles, it is possible to increase the area, and the fine particles do not aggregate or settle. Since it is hard to get off, stable operation can be obtained. Further, since the fine particle adhesion preventing layer is provided on at least one of the inner sides of the pair of substrates, the fine particles are prevented from adhering, and a light control device having a wider variation range of the transmittance can be obtained.

In the light control method of the present invention, the transmittance of light can be changed by applying shear stress to change the arrangement direction of the fine particles or the fine particle aggregate, and the light blocking direction can be selected depending on the displacement direction. , The transmittance control performance for light is significantly improved.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the all-solid-state light control device of the present invention will be described below with reference to the drawings, but the present invention is not limited to such embodiments.

FIG. 1 is a diagram showing an example of the all-solid-state light control device of the present invention when no shear stress is exerted. The angle between the substrate and the long axis direction of the fine particles or fine particle aggregates is
The case of 90 ° is shown.

In FIG. 1, 1 is a substrate and 2 is a particle adhesion preventing layer. In this figure, the particle adhesion preventing layers are provided on both sides. Reference numeral 3 indicates a fine particle or a fine particle aggregate, and 4 indicates a viscoelastic body or an elastic body. FIG. 2 is an explanatory diagram when a shear stress is applied to the device of FIG. The fine particles may be a single fine particle, but usually they exist as an aggregate of a plurality of fine particles.

Any material can be used as the material of the substrate 1 as long as it has been conventionally used in a light control device, and it is not particularly limited, but it has a high light transmittance. preferable. This is because the use of a pair of substrates having high transmittance is a necessary condition for a light control device capable of controlling the light transmittance in a wide range.

Examples of the substrate transparent to light are, for example, glass such as soda lime glass, polyethylene terephthalate, polyvinyl butyral, modified ethylene-
Examples thereof include polymers such as vinyl acetate polymers.

The shape, size, etc. of the substrate 1 are appropriately determined depending on the application and other needs.

When the suspension in which the fine particles are dispersed is an electrorheological fluid, when an electric field is applied to the suspension, the fine particles are electrically polarized and a + portion and a − portion are formed to become a dipole. . The particles that have become dipoles move so as to bring the + side and the − side into contact with each other and bond to each other to form a chain of particles in the direction of the electric field.

When the suspension is such an electrorheological fluid, it is effective to apply an electric field in order to arrange the fine particles or the fine particle aggregates 3 perpendicularly to the substrate as shown in FIG. is there. Therefore, it is desirable that the transparent conductive film is provided inside the two substrates 1. Any material can be used as the transparent conductive film as long as it has been conventionally used in a light control device, and it is not particularly limited, but specific examples thereof include, for example, SnO ₂ film and IT.
An example is an O film. The film thickness is also not particularly limited, but a film thickness that is optically adjusted so as to minimize the reflectance of the light control device is preferable. One example is a SnO ₂ film having a thickness of 180 nm.

Further, when the fine particles are conductors, the fine particles and / or the transparent conductive film are made of, for example, SiO ₂ , A.
It is effective to cover with an insulating film such as l ₂ O ₃ or ZrO ₂ .

A particle adhesion preventing layer is provided on at least one of the inside of the substrate and the inside of the conductive film provided on the substrate.

As the fine particle adhesion preventing layer, any layer can be used as long as it can prevent the adhesion of fine particles.
From the viewpoint of the performance of preventing adhesion of fine particles, for example, a monomolecular layer or a polymolecular layer of polyorganosiloxane or polyimide is preferable.

The polyorganosiloxane is not particularly limited, but examples thereof include polydimethylsiloxane and polyphenylsiloxane.

The polyorganosiloxane is fixed to the surface of the substrate by a strong bond. For example, polyorganosiloxane having a hydrolyzable group such as a methoxy group and an ethoxy group at one end can be used for fixing by a chemical bond.

In order to prevent the adhesion of fine particles, it is most important to lower the interfacial free energy between the viscoelastic body or the elastic body and the substrate, and for that purpose, a substance having a surface tension similar to that of the fine particle dispersion medium. Should be fixed to the substrate surface.

Therefore, the polyorganosiloxane film may be a monomolecular layer or a multimolecular layer.

The degree of polymerization of the polyorganosiloxane is not particularly limited for the above reasons, but it is preferably about 10 to 50 from the viewpoint of the performance of preventing adhesion of fine particles.

As the polyimide used for the particle adhesion preventing layer, any polyimide can be used as long as it is used for the surface treatment of the substrate for a liquid crystal display element.

As with the polyorganosiloxane film, the polyimide film just needs to be able to lower the interfacial free energy, and may be a monomolecular layer or a multimolecular layer.

Therefore, the film thickness is not particularly limited.

By providing the fine particle adhesion preventing layer between the substrate and the elastic body or viscoelastic body in this manner, fine particles are prevented from adhering to the surface of the substrate, so that the transmittance is improved when no shear stress is applied. In addition, since the concentration of fine particles relating to the formation of chain-like substances increases, the transmittance upon application of shear stress decreases, and as a result, the range of change in transmittance increases.

The fine particles or the fine particle aggregates 3 are polarized or magnetized by an electric field, and when dispersed in a liquid, the fine particles or fine particle aggregates are arranged in the direction of the electric field or the magnetic field. However, in order to obtain excellent dimming performance, those having a high light absorption or reflectance are preferable.

The fine particles having a high absorbance are preferably those having an extinction coefficient of 1 × 10 ⁴ cm ⁻¹ or more, and the fine particles having a high reflectance are preferably those having a reflectance comparable to that of a metal.

If the absorbance of the fine particles is high, most of the incident light is absorbed, and the transmittance in the closed state decreases. As a result, the transmittance of sunlight can be controlled in a wide range.

When the light reflectance of the fine particles is high, most of the incident light is reflected to reduce the transmittance in the closed state, and as a result, it is possible to control the transmittance of sunlight in a wide range. Become.

Examples of such fine particles include graphite, TiO _x , TiO _x N _y , titanium oxide coated mica, TiO _x coated mica, TiO _x N _y coated mica,
Titanium oxide coated glass flakes, TiO _x coated glass flakes, TiO _x N _y coated glass flakes, γ-iron oxide, metal titanates, iron, cobalt, magnetite, barium ferrite and chromium (IV) dioxide,
Other examples include various metal-coated mica such as gold and silver, and various metal-coated glass flakes using the same metal as described above.

The range of X in the TiO _x is 1 ≦ x
≦ 2 can be used, and more preferably 1.40 ≦ x ≦ 1.80 from the viewpoint of absorption coefficient. When expressed as an absorption coefficient, it is preferably 5 × 10 ³ cm ⁻¹ or more, and more preferably 1 × 10 ⁴ cm ⁻¹ or more.

Further, the range of x + y in TiOx Ny is 1.37≤x + y≤1.95, and the range of y is 0.15≤y≤0.92.
Is preferable from the viewpoint of extinction coefficient. In this composition range, the extinction coefficient reaches 5 × 10 ³ cm ⁻¹ or more.

These fine particles are not necessarily required to have shape anisotropy, and if the anisotropy is small, or even if there is no anisotropy, the suspension thereof exhibits an electrorheological effect or a magnetic viscous effect. As described above, a chain of fine particles (aggregate 3 of fine particles) can be formed and used.

However, when the fine particles have a shape anisotropy, the attractive force between the fine particles when an external field is applied becomes large, so that the chain of fine particles (aggregate 3 of fine particles) can be easily formed. Further, as is clear from the comparison between FIG. 1 and FIG. 2, the light transmittance control range becomes large.

As for the degree of shape anisotropy, its minor axis is 0.
It is preferably 1 μm or less and an aspect ratio of 3 or more.

The viscoelastic body or the elastic body 4 is shear-deformed from submicron to several tens of microns by a force that does not damage the substrate when shear stress is applied (value of d in FIG. 2).
Then, any viscoelastic body or elastic body can be used as long as the original arrangement of the fine particles or the fine particle aggregate can be maintained when the force is released. for that purpose,
The shear modulus (G ') of the viscoelastic body or elastic body when measured at room temperature and a frequency of 1 Hz is 1 × 10 ² ≦ G ′ ≦ 1 × 10 ⁷
dyn / cm ² , and further 1 × 10 ³ ≦ G ′ ≦ 1 × 10 ⁵ dyn
/ Cm ² is preferable.

If the shear modulus is less than 1 × 10 ² dyn / cm ² , the viscoelastic body or elastic body is too soft,
It becomes difficult to maintain the arrangement of the fine particles or the fine particle aggregates.
Further, if it is larger than 1 × 10 ⁷ dyn / cm ² , a very large force is required to displace the substrate, which makes it difficult to use.

Preferred examples of the viscoelastic body or elastic body include, for example, thermosetting polymers, photocurable polymers, electron beam curable polymers, radiation curable polymers, plasma curable polymers or hydrogen bonds, electrostatic bonds or bonds. Examples thereof include cross-linked inorganic polymers or cross-linked organic polymers such as those having a three-dimensional network structure by position bonds, and polymers containing one or more of them.

Specifically, for example, polymers of various vinyl monomers and divinyl compounds, polyacrylic acid, polymethacrylic acid, polyacrylamide, compounds having a hydroxyl group-containing polymer and an aldehyde, mixtures of polyvinyl alcohol and 2-oxazolines, Polyethylene, α-substituted polymer, polyvinylidene fluoride, polytetrafluoroethylene, nylon, polyvinyl fluoride, interpolymer complex of PAA and PVA, polyvinyl alcohol-Cu
²⁺ , polyacrylic acid-Fe ³⁺ , polyacrylic acid-C
^Examples include u ²⁺ and polyorganosiloxane.

When the light control device is used as a window material for construction and vehicles, it is in contact with the external environment directly, so that the range from -20 to
It must operate stably in the temperature range of + 80 ° C. For that purpose, a material having a small temperature dependence of the viscoelastic modulus of the viscoelastic body or the elastic modulus of the elastic body is preferable. From this point of view, among the above viscoelastic materials or elastic materials, polyorganosiloxane, thermosetting polyorganosiloxane, and photocuring polyorganosiloxane are preferable. In addition, polyorganosiloxane is a material having excellent weather resistance, and is particularly preferable as a viscoelastic body or elastic body for a light control device.

As described above, such a viscoelastic body or elastic body is deformed in response to a shear stress, but returns to the original state when the stress is removed with good reproducibility. Can be repeated, improving the repeatability of the dimmer.

Examples of the device that exerts shear stress include an actuator that converts an electric signal into a mechanical signal,
If this is used, an arbitrary shear stress can be obtained by controlling the voltage.

The viscoelastic body or elastic body 4 is made into a viscoelastic body or an elastic body in the state where an electric field or a magnetic field is applied, and the fine particles or the fine particle aggregates 3 therein are slightly different from the substrate. Although there is a deviation in the angle, it is often the case that the aggregate is formed in a state in which it is oriented and aligned in a substantially constant direction.

The fixed direction means not only the case where all the fine particles or the fine particle aggregates are perfectly aligned and aligned in a fixed direction, but also the substantially uniform direction and alignment, and the alignment and alignment in a fixed direction as a whole. It is meant to include the case.

In order to efficiently control the light transmittance when a shear stress is exerted, the fine particle content is preferably 0.07 to 7.0% by volume, more preferably 0.7 to 2.3% by volume,
The thickness of the viscoelastic body or elastic body 4 is preferably 5 to 100 μm, more preferably 10 to 50 μm.

Size of one fine particle or fine particle aggregate 3 (hereinafter referred to as a block) (value of a in FIG. 1)
Is preferably 10 μm or less, more preferably 4 μm or less. Further, the number density of blocks is preferably 2.0 × 10 ⁵ pieces / cm ² or more, more preferably 7.0 × 10 ⁵ pieces / cm ² or more.

The light control device having the above structure can be manufactured to have a size of about 1 m × 2 m square.

The all-solid-state light control device of the present invention uses a solid dispersion medium that does not scatter upon leakage or breakage as a fine particle dispersion medium, and adjusts the shear stress exerted on the dispersion medium in multiple stages. The transmittance can be controlled. In addition, the provision of the particle adhesion preventing layer on at least one of the inside of the substrate further improves the solar energy transmittance control performance.

Next, a method for manufacturing the all-solid-state light control device of the present invention will be described.

There are two methods of arranging the fine particles or the fine particle aggregates 3 in a certain direction with respect to the substrate, a method of applying a voltage and a method of applying a magnetic field, and the manufacturing method differs depending on the method.

First, a method of manufacturing an all-solid-state light control device by applying a voltage will be described.

First, if necessary, an insulating film is formed on the side of the pair of substrates having electrodes formed therein on the side where the electrodes are formed, and a fine particle adhesion preventing layer is further provided on at least one of the insulating films. A method may be mentioned in which a suspension containing fine particles that are polarized by an electric field is sandwiched between substrates, and then the suspension is made viscoelastic or elastic while applying a voltage between the substrates.

As a method for providing the fine particle adhesion preventing layer,
The following methods are available. One way is
Reactive to the surface of the substrate, eg of formula (I):

[0065]

[Chemical 1]

Polydimethylsiloxane derivative such as polydimethylsiloxane having three methoxy groups at one end thereof, polyphenylsiloxane having reactivity with the surface of the substrate, formula (II):

[0067]

[Chemical 2]

A substrate coated with an insulating material such as polyorganosiloxane having the structure of from room temperature to 200
0.5 to 5 in polyorganosiloxane liquid heated to ℃
A method of providing a fine particle adhesion prevention layer by immersing for a time is mentioned.

By the above method, a polyorganosiloxane film having a thickness of 0.001 to 0.05 μm can be obtained.

As another method, for example, there is a method of coating a solution containing 10 to 30% by weight of polyimide in a solvent by a screen printing method.
By the above method, a polyimide film having a thickness of 0.01 to 0.1 μm can be obtained.

Using the substrate provided with the fine particle adhesion preventing layer as described above, first, one or more fine particles are mixed with the viscoelastic material or the raw material liquid of the elastic material, and if necessary, a catalyst or the like is added. Add to make a suspension, the suspension,
It is applied onto the substrate by a method such as screen printing, and is set so as to have a constant space between the pair of substrates. Next, various operations such as heating are performed while applying a voltage to make the suspension viscoelastic or elastic while the fine particles are oriented. Therefore, the thickness of the viscoelastic body or the elastic body is determined by the distance between the set substrates.

As an example of the method of setting the substrates, it is possible to keep the distance between the substrates constant by adding, for example, spherical particles having a uniform particle size to the suspension as spacers. . In this case, the distance between the substrates is determined by the diameter of the spacer.

The applied voltage depends on the viscosity of the dispersion and the chain forming ability of fine particles, but an electric field of 10 ⁴ Vcm ^-1 or more is usually sufficient.

The surface of the substrate is usually insulated with an oxide such as SiO ₂ or Al ₂ O ₃ . Since a large van der Waals force acts between the substrate surface and the fine particles, the fine particles tend to adhere to the substrate surface. By coating the surface of the substrate with a polyorganosiloxane or a polyimide film, the van der Waals force is reduced and a repulsive force is generated when the particles approach each other, so that the adhesion of the particles can be effectively prevented.

The suspension is made viscoelastic or elastic by leaving a suspension containing fine particles sandwiched between a pair of substrates while applying a voltage by electrodes formed on the surfaces of the substrates.
The suspension is made viscoelastic or elastic by heating, light irradiation, electron beam irradiation, radiation irradiation, plasma irradiation, or the like.

In this case, in order to obtain a good adhesive force between the viscoelastic body or the elastic body and the substrate, the suspension is viscoelastic or elastic body is sandwiched between the substrates. Since it needs to be carried out, it is particularly preferable to use a thermosetting or photocurable polymer as the dispersion liquid of the fine particles.

Further, from the viewpoints of the weather resistance and the temperature dependence of the elastic modulus, the thermosetting polyorganosiloxane or the photocuring polyorganosiloxane is particularly preferable.

Next, as a method of manufacturing an all-solid-state light control device by applying a magnetic field, a method similar to the above-mentioned method is used, in which a pair of substrates provided with a particle adhesion preventing layer are provided.
There is a method in which a suspension containing magnetic particles is sandwiched and then the suspension is made viscoelastic or elastic while applying a magnetic field between the substrates, except that a magnetic field is applied to the suspension. Is exactly the same as the manufacturing method of the all-solid-state light control device by the method of applying the voltage.

The manufacturing method of the all-solid-state light control device by applying the magnetic field has an advantage that the angle (θ) formed by the block and the substrate can be arbitrarily set by selecting the direction of the magnetic field. On the other hand, in the method of applying the voltage,
θ inevitably becomes 90 °.

As a method of applying a magnetic field, for example, 2
Two solenoids connected in series may be installed in parallel and the parallel magnetic field generated between them may be used.

In this case, if the angle between the substrate and the magnetic field is selected and then the suspension is made viscoelastic or elastic, fine particles or fine particle aggregates arranged in any direction with respect to the substrate. A viscoelastic body or elastic body containing a body can be obtained.

The strength of the magnetic field varies depending on the type of magnetic particles used, but as an example, in the case of γ-iron oxide, a magnetic field of 5 kOe or more is used to obtain a fine arrangement of fine particles. Needed for.

When forming a chain of fine particles by using a magnetic field, it is possible to prevent the adhesion of fine particles basically by the same principle as when an electric field is used.

The manufacturing method of the all-solid-state light control device of the present invention can easily manufacture a large area device by a method such as screen printing.

Further, a dimming method using the all solid state dimming device will be described. The dimming method uses the all-solid-state dimming device having the above-described configuration, and applies shear stress to the viscoelastic body or elastic body by a device that applies shear stress.

The specific method will be described with reference to FIGS. 1 and 2. FIG. 1 is an explanatory view showing an open state in which no shear stress is exerted in the light control device of the present invention, and FIG. 2 shows the light control device. It is explanatory drawing which shows the closed state which is exerting shear stress. The symbols are as described above. Here, since the fine particles or the fine particle aggregate 3 is often an aggregate of a single fine particle, the fine particles or the fine particle aggregate 3 will be described as an aggregate of fine particles.

In FIG. 1, the fine particles are arranged in the direction perpendicular to the substrate. Therefore, in this case, since the light shielding area of the fine particles is small and the fine particles adhered are smaller than in the conventional case, most of the sunlight is transmitted.

When a shear stress is applied to the viscoelastic body or the elastic body 4 containing the fine particles or fine particle aggregates 3 having the structure as shown in FIG. 1, the fine particles or fine particle aggregates 3 become long as shown in FIG. The axes are arranged parallel to each other with the axes inclined in the shear stress direction.

Since the light control device in this state has a large light-shielding cross-sectional area by the fine particles, most of the light is absorbed when the fine particles having a high absorbance are used. Further, most of the light is reflected when the highly reflective fine particles are used.

In this case, the lateral displacement of the substrate for exerting the shear stress varies depending on the physical properties of the viscoelastic body or the elastic body and the thickness thereof, but the all solid state of the present invention provided with the fine particle adhesion prevention layer. In a dimmer, for example, a thickness of about 20
Displacement of 4 μm or more in the case of μm, transmittance decreases by 20 to 25% when a particle adhesion prevention layer is provided on one side, and decreases by 35 to 40% when particle adhesion prevention layers are provided on both sides. To do.
Further, when the extinction coefficient is sufficiently large, the transmittance change width increases substantially in proportion to the displacement amount.

The displacement amount can be controlled by the voltage using the actuator as described above as the device exerting the shear stress.

When the shear stress is released, the fine particles or the fine particle aggregate 3 returns to the initial state as shown in FIG.

Further, if the initial state is not completely returned due to the stress relaxation of the viscoelastic body or the elastic body, the actuator can forcefully restore the initial state. This point is important in the sense that the switching performance of this device is not affected by the stress relaxation of the viscoelastic body or elastic body.

Since such a light control method is used, the transmittance can be controlled in multiple stages by changing the displacement amount of the substrate, and the light blocking direction can be selected according to the displacement direction. it can.

By the light control method, the change width of the light transmittance can be controlled by about 35 to 40%, and the change width of the light transmittance hardly changes even after using about 10 ⁶ times,
It has a transmittance control performance equivalent to the initial transmittance change width of the liquid DPS element.

The all-solid-state light control device of the present invention can be suitably used in a wide range such as building and automobile window glass.

Next, the present invention will be described in detail based on examples, but the present invention is not limited to such examples.

Example 1 First, ITO having a thickness of 30 ± 10 nm coated with about 500 nm silica.
A film-coated glass substrate (50 mm × 100 mm, thickness 1.1 mm) was used as a substrate, and the substrate was heated to 200 ° C. (I):

[0099]

[Chemical 3]

After dipping in a liquid of polydimer siloxane (n = 18) having 3 methoxy groups at one end represented by the formula (2) for 2 hours, it was pulled up and washed with toluene. Due to the surface treatment, a coating layer having a substantially monomolecular layer was formed on the surface of the substrate.

Next, needle-like TiO _x N _y (x = 0.75, y) coated with a silica insulating film having an absorption coefficient of about 10 ⁵ cm ^-1 , a major axis length of about 0.5 μm, and an aspect ratio of about 6.5. = 0.
75) together with a trace amount of pearl spacers having a diameter of 24 μm, a silicone gel raw material solution (KE1052 manufactured by Shin-Etsu Chemical Co., Ltd., which is composed of two liquids A and B, and the mixing ratio of liquids A and B is 1: 1 (used in a weight ratio)) to prepare a suspension having a fine particle content of about 3% by weight. This was dropped on the glass substrate with the ITO film that had been subjected to the above surface treatment, sandwiched between counter substrates that had been subjected to the same treatment, and heated at about 60 ° C. for 2 hours while applying a voltage of 80 V, and thus gelled. The reaction proceeded.

Observation of the thus obtained all-solid-state light control cell with an optical microscope revealed that needle-like fine particles were oriented and aggregated to form a columnar aggregate perpendicular to the substrate as shown in FIG. Was observed. Size a of the columnar aggregate (Fig. 1
Is about 2 μm and the length is almost equal to the distance between the substrates.
It was found to be μm.

One of the cell substrates was fixed and the other was connected to a probe of an actuator to manufacture an all-solid-state dimmer capable of controlling the displacement amount by voltage.

The relative displacement amount between the substrates is reduced by using the driving device.
FIG. 3 shows spectra of transmitted light before and after applying shear stress when controlled to 30 μm.

Example 2 The same glass substrate as the ITO film used in Example 1 was used, and the substrate was heated to 150 ° C. to obtain formula (II):

[0106]

[Chemical 4]

Three methoxy groups at one end represented by
It is immersed in a liquid of polyorganosiloxane (n = 18) having a trimethylsilyl ester group at the other end and nitrogen is added to 20
It was kept for 2 hours while flowing at 0 ml / min.

After the above surface treatment, it was pulled up and washed with toluene. By the surface treatment, almost a monolayer was formed on the surface of the substrate.

Next, an all-solid-state dimming cell was obtained in the same manner as in Example 1 except that the above-mentioned surface-treated substrate was used.

When the obtained all-solid-state light control cell was observed with an optical microscope, it was observed that plate-like fine particles were oriented and aggregated to form a columnar block perpendicular to the substrate as shown in FIG. It was

An all-solid-state light control device was manufactured by using the above-mentioned cell in the same manner as in Example 1, and the spectra of transmitted light before and after the application of shear stress were similarly measured. The result is shown in FIG.

Comparative Example 1 An all-solid-state light control device was manufactured in the same manner as in Example 1 except that the fine particle adhesion preventing layer was not provided, and the spectra of transmitted light before and after the application of shear stress were measured. The result is shown in FIG.

When any of the solid-state light control devices of Examples 1 and 2 and Comparative Example 1 was used, by applying shear stress between the substrates, a large transmittance was obtained in the visible to near infrared region. It can be seen that is changing. Furthermore, Comparative Example 1
Compared to the all-solid-state dimmer (variation range of sunlight transmittance = 22.2%), the surface treatment with polyorganosiloxane increases the transmittance when no shear stress is applied, and when shear stress is applied. It can be seen that as a result of the decrease in the transmittance of No. 1, the range of change in the sunlight transmittance is significantly increased. The all-solid-state light control device of Example 1 showed a change in sunlight transmittance of 35.6%, and the all-solid-state light control device of Example 2 showed a change in sunlight transmittance of 39.3%. The solar light transmittance change width was calculated from the values obtained by applying the following formula to the solar light transmittance when a shear stress was applied and when no shear stress was applied.

[0114]

[Equation 1]

However, T (λ) is the transmittance of sunlight at the wavelength λ, E (λ) is the sunlight energy at the wavelength λ, and the integral according to the above equation is 0.34 ≦ λ at the wavelength λ.
It was performed in the range of ≦ 2.1 μm.

When the surface of the substrate was observed with a microscope,
As a result of the surface treatment with polyorganosiloxane, it was confirmed that the amount of fine particles adhering to the substrate surface was significantly reduced as compared with the untreated substrate. Therefore, it is considered that the transmittance was increased when no shear stress was applied.

Further, since the surface treatment of the substrate increases the concentration of fine particles involved in the formation of chains, the transmittance at the time of applying the shear stress is reduced as compared with the dimmer cell using the untreated substrate. it is conceivable that.

Example 3 A needle-shaped T coated with a silica insulating film having an extinction coefficient of about 10 ⁵ cm ^-1 , a major axis length of about 0.5 μm and an aspect ratio of about 6.5.
iO _x N _y fine particles (x = 0.75, y = 0.75) with a diameter of 24μ
A small amount of pearl spacers of m together with silicone gel raw material solution (KE1052 manufactured by Shin-Etsu Chemical Co., Ltd.
It consists of two liquids, liquid A and liquid B, and the mixing ratio of liquids A and B is 1: 1
(Used by weight ratio)) to prepare a suspension having a fine particle content of about 3% by weight.

Next, the polyimide film (thickness 0.03 μm) coated by a screen printing method was dropped onto an ITO glass substrate (the same substrate as in Example 1), sandwiched between counter substrates, and a voltage of 80 V was applied. The gelation reaction was allowed to proceed by heating at about 60 ° C. for 2 hours to prepare an all-solid-state light control cell.

An all-solid-state light control device was manufactured using the all-solid-state light control cell, shear stress was applied, and the relative displacement between the substrates was controlled to about 30 μm. The change in transmission spectrum before and after the application of shear stress is shown in FIG. From this, untreated SiO ₂
It can be seen that the width of change in sunlight transmittance is significantly increased (width of change in sunlight transmittance = 42.7%) as compared with the case where the coated ITO glass substrate is used (Comparative Example 1). The solar light transmittance change width was also obtained in the same manner as in Example 1.

Furthermore, when the obtained cell was observed with an optical microscope, the amount of fine particles adhering to the polyimide-coated substrate was found to be
It was confirmed that the amount was remarkably reduced as compared with the untreated substrate.

[0122]

As described above, the light control device of the present invention and the light control method using the same can control the transmittance in multiple stages by changing the displacement amount of the substrate. It has a remarkably high solar energy transmittance control performance that it is possible to control the light shielding direction depending on the direction.

Further, in the present invention, since the particle adhesion preventing layer is provided on at least one of the inside of the substrate, the variation range of the solar light transmittance becomes extremely high at 35 to 40%.

Further, since the viscoelastic body or the elastic body, which is a dispersion medium of fine particles, is a solid or a semi-solid, the operation is stabilized, and the dispersion medium can be prevented from leaking or scattering at the time of breakage. Can be used to improve the reliability and safety.

Further, since the all-solid-state light control device of the present invention can apply a fine particle suspension, which is a raw material of a viscoelastic body or an elastic body, to a substrate by using a screen printing method or the like, it can be used as a large area light control device. Become.

From the above, the all-solid-state light control device of the present invention can be preferably used in a wide range such as window glass for buildings and automobiles.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a high light transmission state (open state) in the absence of shear stress in the all-solid-state light control device of the present invention (where θ = 90 °).

FIG. 2 is an explanatory view showing a low light transmittance state (closed state) in the presence of shear stress in the all-solid-state light control device of the present invention (however, the fine particles or the fine particle aggregates are the light absorbing fine particles). In case of).

FIG. 3 is a graph showing changes in transmitted light spectrum when shear stress is applied and when no all-solid-state dimmers of Example 1, Example 2 and Comparative Example 1 are used.

FIG. 4 is a graph showing changes in transmitted light spectrum when a shear stress is applied and when no shear stress is applied when the all-solid-state light control device of Example 3 is used.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Particle adhesion prevention layer 3 Particles or particle aggregates 4 Viscoelastic body or elastic body

Claims (10)

[Claims] 1. A viscoelastic body comprising a pair of substrates each having a particulate adhesion preventing layer provided on at least one of the insides of opposing substrates, and particulates or particulate aggregates arranged between the substrates in a certain direction with respect to the substrates. Alternatively, an all-solid-state light control device comprising an elastic body and a device that exerts shear stress on the viscoelastic body or the elastic body. 2. The fine particles are light absorbing and / or
The all-solid-state light control device according to claim 1, wherein the all-solid-state light control device is light-reflecting fine particles. 3. The fine particles are graphite or TiO.
_x (1 ≦ x ≦ 2), TiO _x N _y (1.37 ≦ x + y ≦ 1.9
5, 0.15 ≦ y ≦ 0.92), titanium oxide coated mica, TiO
_x coated mica (1 ≦ x <2), TiO _x N _y coated mica (1.37 ≦ x + y ≦ 1.95, 0.15 ≦ y ≦ 0.92), metal coated mica, titanium oxide coated glass flake, TiO _x coated glass flake (1 ≦ x <2), TiO _x N _y coated glass flakes (1.37 ≦ x + y ≦ 1.95, 0.15 ≦ y ≦ 0.92), metal coated glass flakes, γ-iron oxide, metal titanate salt,
The all-solid-state light control device according to claim 1 or 2, which is one or more kinds of fine particles selected from the group consisting of iron, cobalt, magnetite, barium ferrite and chromium (IV) dioxide. 4. The all-solid-state light control device according to claim 1, wherein the fine particles have shape anisotropy. 5. The viscoelastic body or elastic body has a shear modulus (G ′) of 1 × 10 ² ≦ G ′ ≦ 1 × 10 ⁷ dyn / cm at room temperature.
Organic (and / or) in the range of ² (measurement frequency is 1 Hz)
The all-solid-state light control device according to claim 1, which is composed of an inorganic polymer cross-linked body. 6. The viscoelastic body or the main component of the elastic body is polyorganosiloxane.
The all-solid-state light control device described. 7. The all-solid-state light control device according to claim 1, wherein a main component of the viscoelastic body or the elastic body is a thermosetting polyorganosiloxane. 8. The all-solid-state light control device according to claim 1, wherein a main component of the viscoelastic body or the elastic body is a photocurable polyorganosiloxane. 9. The dimming method according to claim 1, wherein a shear stress is exerted on the viscoelastic body or the elastic body of the all-solid-state dimming device by a device that exerts shear stress to control the light transmittance. . 10. The all-solid-state light control device according to claim 1, wherein a device for exerting a shear stress on the viscoelastic body or the elastic body controls the direction of the shear stress to select the transmittance of light in an arbitrary direction. 10. The dimming method according to claim 9, wherein the dimming method is controlled physically.