JPH075503A - Particle dispersion type light control element - Google Patents

Abstract

PURPOSE:To provide the particle dispersion type light control element having excellent UV resistance by using polarizable particles consisting of complex crystals composed of the cations of a polycyclic arom. compd. and tri-iodine anions. CONSTITUTION:This light control element is constituted by sealing the complex crystals 6 composed of the cations of the polycyclic arom. compd. having at least one nitrogen atoms and an arom. ring condensed with at least three rings and the tri-iodine anions between a pair of glass substrates 1 and 2. A UV shielding film 11 is formed on at least one surface of the glass substrate on at least the side where light is made incident. The irradiation of the complex crystals with UV rays is prevented by this UV shielding film and the life of the plate is prolonged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a particle-dispersed light control device having polarizing particles as a main constituent element. This particle-dispersed light control element is used for a light valve, light control glass, and the like.

[0002]

2. Description of the Related Art Light control glass is a glass having a function of controlling the amount of light passing through, and a glass having the function itself and a substance having the function are interposed between two pieces of glass. Two types of things are known. It is known that the former glass itself has such a function that contains a photochromic material on the glass surface or inside,
It is used for sunglasses. This utilizes the property of a photochromic material that is colored by light and shielded from light, and disappears and disappears when light disappears.

As an example of the latter, there is known a light control glass in which a liquid crystal is sealed between two glass substrates and configured with a polarizing plate, which is used for an antiglare mirror of an automobile. This utilizes the property that the orientation of the liquid crystal changes due to the application of a voltage. Further, in recent years, attempts have been made to disperse particles in a dispersion medium and orient the particles by an electric field to control optical characteristics such as transmittance, reflectance, and scattering rate. The particles used here are those disclosed in
46-4464 publication and U.S. Pat.
Mica, graphite, and herapatite have been reported frequently. Especially to control the transmittance in the colored state,
As described in JP-A-53-144893, polarizing particles such as herapatite and dihydrocinchonidine sulfate periodate are suitable.

[0004]

In order to apply polarizing particles such as herapatite and dihydrocinchonidine sulfate periodate as a light control element, the polarizing particles are dispersed in a dispersion medium, and a pair of glass is used. It is necessary to have a structure in which it is sealed between the substrates, or to mix it in resin to form a film-shaped element.

However, since the above-mentioned polarizing particles are poor in water resistance and heat resistance, there is a problem that they are deteriorated by water contained in a dispersion medium or a resin or decomposed by heating when forming a laminated glass. Therefore, the inventors of the present application have previously proposed, as a polarizing particle having sufficient water resistance and heat resistance, a polarizing particle composed of a complex crystal composed of a cation of a polycyclic aromatic compound and a triiodine anion. It is being developed (Japanese Patent Application No. 4-325592). By using this polarizing particle, a long-life particle-dispersion type light control element can be formed.

However, even with such polarizing particles, it is necessary to anticipate that they will be exposed to sunlight or the like for a long period of time in their use state.
Further measures against discoloration due to ultraviolet rays of nm or less are desired. The present invention has been made in view of such circumstances, and an object of the present invention is to provide a particle-dispersed light control device excellent in ultraviolet resistance by using the polarizing particles.

[0007]

In a particle-dispersed light control device of the present invention for solving the above problems, at least one nitrogen atom and at least three rings are provided between a pair of glass substrates facing each other with a predetermined distance. A particle-dispersed light control device, in which a complex crystal composed of a cation of a polycyclic aromatic compound having a condensed aromatic ring and a triiodine anion is enclosed, at least a side on which light is incident. An ultraviolet shielding film is provided on at least one surface of the glass substrate.

At least one nitrogen atom and at least 3
As the polycyclic aromatic compound having an aromatic ring in which two rings are condensed, for example, acridine, phenanthridine, 1,
7-phenanthroline, 1,10-phenanthroline, 4,7-phenanthroline, phenazine, phenoxazine, phenothiazine, carbazole, iminostilbene, and the above nitrogen-containing polycyclic aromatic compound or at least three rings containing no nitrogen atom are condensed To the polycyclic aromatic compound
Examples thereof include compounds in which a group containing a nitrogen atom such as an amino group, an amide group, a hydrazide group, an imino group, and a guanidyl group is bonded.

Further, the polycyclic aromatic compound has a halogen substituent as a derivative of the above compound, a hydrocarbon substituent having 10 or less carbon atoms, or a substituent in which these are bonded via a sulfur atom or an oxygen atom. Also includes those with. Examples of the substituent bonded via a sulfur atom or an oxygen atom include a methoxy group, an ethoxy group, a phenoxy group, a methylthio group, an ethylthio group and a phenylthio group.

In order to form a complex crystal as a polarizing particle, an acid is added to the above polycyclic aromatic compound to neutralize a base based on a nitrogen atom, and an aqueous solution is prepared as a water-soluble neutral salt. By adding and mixing an aqueous solution containing a mixture of iodine and potassium iodide and containing potassium ions and iodine ions, a complex exhibiting charge transfer is precipitated as crystals.

As the ultraviolet ray shielding film, known ultraviolet ray shielding films such as those using titanium oxide or cerium oxide described in JP-A-63-104028 can be used. It is particularly preferable to use a complex oxide of cerium oxide and an oxide of a metal having a higher valence than cerium, which is described in Japanese Patent Application No. 4-149883 filed by the present applicant.

[0012]

In the complex crystal as the polarizing particle used in the present invention, the large spread of the polycyclic aromatic compound covers the 3 iodide anions forming the complex and protects the complex structure from attack of water and oxygen. At the same time, it stabilizes the entire molecule stereochemically. Therefore, this complex crystal has stability, heat resistance,
Excellent water resistance.

This complex crystal has a structure in which polycyclic aromatic compound cations and triiodine anions are regularly arranged in a plane structure, and thereby exhibits polarization. Also, this 2
Depending on the type of ion, a charge-transfer complex in which electrons easily move is formed, so that polarizability is increased. Therefore, in the light control device of the present invention using this complex crystal, the complex crystal is oriented in the direction perpendicular to the glass substrate by applying a voltage between the two glass substrates, so that the transmittance of incident light is increased. Also,
When the application of the voltage is stopped, the orientation of the complex crystal becomes random, and the incident light is absorbed and reflected, so that the transmittance decreases and the color tone of the complex crystal itself appears.

It is considered that this complex crystal is colored by arranging iodine ions in a straight line. Then, it is considered that the structure of the crystal composed of iodine ions and polycyclic aromatic compound ions is changed by irradiating the iodine ions with ultraviolet rays. Therefore, in the light control element of the present invention,
This complex crystal is included as polarizing particles, and an ultraviolet shielding film is provided on one surface of the glass substrate on the side where light is incident. Therefore, since the complex crystal is prevented from being irradiated with ultraviolet rays, deterioration of decoloring due to ultraviolet rays is prevented, and the light control element has a long life.

[0015]

EXAMPLES The present invention will be specifically described below with reference to examples. (Embodiment) FIG. 1 shows a schematic sectional view of a light control element according to an embodiment of the present invention. This light control element has a thickness that is located on the light incident side.
1.1mm first glass substrate 1 and thickness on the viewing side 1.
The second glass substrate 2 of 1 mm faces in parallel with the sealing epoxy adhesive 3 and the spacer 4 at a predetermined interval of 100 μm. Transparent conductive films 10 and 20 made of ITO, SnO ₂ or the like and having a thickness of 1500 Å are formed on the surfaces of the first glass substrate 1 and the second glass substrate 2 which face each other. Further, on the outer surface of the first glass substrate 1, a transparent ultraviolet shielding film 11 made of a complex oxide mainly composed of cerium oxide is formed.

In a closed space formed between a pair of glass substrates 1 and 2, a dispersion medium 5 made of ditridecyl phthalate and polarizing particles 6 made of phenanthroline complex crystals dispersed in the dispersion medium. A dispersion liquid consisting of is enclosed. This dispersion was formed as follows. Five-
1.16 g of methoxy-1,10-phenanthroline was dissolved in a mixed solution of 21 g of water and 0.138 g of concentrated sulfuric acid to prepare a first solution.
Next, 0.708 g of iodine and 0.468 g of potassium iodide were dissolved in a mixed solution of 14 g of water and 3.5 g of ethanol to prepare a second solution. Then mix the first solution and the second solution at once,
After stirring for 1 hour, the resulting precipitate was filtered, washed with water, and vacuum dried to obtain 2.13 g of dark green fibrous crystals.

This crystal was analyzed by X-ray diffraction, elemental analysis, Raman spectrum and infrared absorption method to give 5-methoxy-1,10-
It was confirmed to be a complex crystal of phenanthroline periodate. According to the DSC method, the melting point of this complex crystal is 22.
It was 9.5 ° C. 10 g of ethanol to 0.2 g of this complex crystal
Was added and the product was washed with an ultrasonic cleaner for 10 minutes. Then, 10 g of ditridecyl phthalate was added to 0.2 g of the isolated polarizing particles 6 (complex crystal), and dispersed with an ultrasonic cleaner for 1 hour.
Then, the mixture was treated in a vacuum atmosphere to remove volatile components such as ethanol and obtain a blue dispersion liquid.

The dispersion was heat-treated at 130 ° C. for 10 hours, but no discoloration was observed before and after heating. The ultraviolet shielding film 11 was formed as follows. Commercially available cerium acetylacetonate (III) [Ce
_{(CH 3 COCHCOCH 3) 3 ·} 3H 2 O ] 100 parts by weight, pentaethoxyniobium [Nb (OC ₂ H _{5) 5]} 19.5 parts by weight, diethanolamine _{[HN (CH 2 CH 2 OH)} 2 ] 89.5 parts by weight n - butyl alcohol _{[CH 3 (CH 2) 2 CH} 2 OH ] 890.0 advance by mixing parts by weight, were added 23.3 parts by weight pentaethoxyniobium thereto.

This mixed solution was placed in a flask and heated to 130-140
Refluxing was carried out at 0 ° C for 2 hours to obtain a dark brown solution. This solution was coated on one surface of the first glass substrate 1 by spin coating. After that, it was dried in a dryer at 120 ° C. for 10 minutes and further baked in air at 500 ° C. for 20 minutes to obtain an ultraviolet shielding film 11. When the film thickness obtained by one film formation was small, the film formation was repeated several times to make the film thickness about 1000Å.

FIG. 2 shows the result of measuring the transmittance of each wavelength light of the ultraviolet shielding film 11. From Figure 2, 4% at 365 nm
It can be seen that the transmittance is about the same, and most of the ultraviolet rays with a wavelength of 365 nm or less are blocked. When an AC voltage of 50 V is applied using the pair of transparent conductive films 10 and 20 of this light control element as electrodes, the polarizing particles 6 are vertically aligned with respect to the glass substrates 1 and 2 as shown in FIG. Becomes higher. On the other hand, when the voltage application is stopped, the orientation of the polarizing particles 6 becomes random as shown in FIG. 1, so that the transmittance decreases due to absorption and reflection of light, and the polarizing particles 6 themselves appear to be colored blue. . (Test) As a comparative example, a light control element similar to that of the example except that the ultraviolet light shielding film 11 was not provided was prepared and subjected to a weather resistance test. The weather resistance test uses a Sunshine weather meter (SWM) manufactured by Suga Test Instruments, and the black panel temperature is 63 ° C.
The conditions were 100 hours. The results are shown in Fig. 4.

In the light control device of the comparative example, the transmittance changed from 38 to 80% as shown in FIG. 4, and the blue one became completely colorless at first. However, SWM contains light of various wavelengths from the ultraviolet region to the infrared region, and it is unclear which wavelength region the light influences. Therefore, we conducted an experiment by irradiating with light of various wavelengths and found that it was weak in the wavelength of the ultraviolet region, and when irradiated with an ultraviolet lamp centered on a wavelength of 365 nm, it was 30
After 0 hours of irradiation, the transmittance became 80%.

On the other hand, in the light control element of the example, a weather resistance test was conducted by irradiating from the surface side of the first glass substrate 1 with the SWM in the same manner as above, and as shown in FIG. Is 50% or less, and although not shown, it was found that when an AC voltage of 50 V was applied, the transmittance was improved to 80%, and there was no practical problem. From the comparison with the comparative example, it is clear that the small change in the transmittance of the light control device of the example is due to the fact that it has the ultraviolet shielding film 11 that almost shields ultraviolet rays of 365 nm or less.

In this embodiment, the ultraviolet shielding film 11 is formed only on the outer surface of the first glass substrate 1, but the present invention is not limited to this, and it is formed only on the inner surface of the first glass substrate 1. It may be formed on both the outer and inner surfaces. When it is formed on the inner surface, it may be formed on the surface of the transparent conductive film 10.

[0024]

That is, the particle-dispersed light control device of the present invention is excellent in durability because it is excellent in ultraviolet resistance.
Further, if the ultraviolet shielding film is formed on the inner surface of the transparent conductive film, the ultraviolet shielding film is an insulating film, so that a short circuit can be prevented.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a particle dispersion type light control device of one embodiment of the present invention when no voltage is applied.

FIG. 2 is a graph showing the relationship between the wavelength and the transmittance of the ultraviolet shielding film formed in the particle dispersion type light control device of one embodiment of the present invention.

FIG. 3 is a schematic cross-sectional view of a particle-dispersed light control device of one example of the present invention when a voltage is applied.

FIG. 4 is a graph showing the relationship between light resistance test time and transmittance in the light control elements of the example and the comparative example.

[Explanation of symbols]

1: First glass substrate 2: Second glass substrate 3: Adhesive for sealing 4: Spacer 5: Dispersion medium 6: Polarizing particles (complex crystal) 10, 20: Transparent conductive film 11: Ultraviolet shielding film

Front Page Continuation (72) Inventor Toshiro Okamoto 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Kazuo Tojima 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Invention Person Akira Usuki Ari 41, Nagachote-cho, Aichi-gun, Aichi Prefecture 1 41, Yokomichi, Toyota Central Research Institute, Inc. (72) Inventor Hisato Takeuchi 1 41, Yokochi, Nagakute-machi, Aichi-gun, Aichi Prefecture, Ltd. Toyota Central Research Institute (72) Inventor Akane Okada 1 of 41, Yokochi, Nagakute-cho, Aichi-gun, Aichi-gun

Claims (1)

[Claims] 1. A cation of a polycyclic aromatic compound having at least one nitrogen atom and an aromatic ring formed by condensing at least three rings between a pair of glass substrates facing each other with a predetermined distance and triiodine. A particle-dispersed light control device encapsulating a complex crystal composed of anions, characterized in that an ultraviolet shielding film is provided on at least one surface of the glass substrate on which at least light is incident. Particle dispersion type light control element.