JP2002169192A - Optical element and modulation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical element which has a large variation of light scattering rate, reflectance or the like, stable repetition characteristics and a constitution which can be manufactured easily, and to provide a modulation method. SOLUTION: The optical element has at least a stimuli-sensitive polymer gel which swells or shrinks by an external stimulus and has redox ability, and a liquid absorbable in the stimuli-sensitive polymer gel between an oxidation reduction electrodes having a transparent electrode and redox ability, and the stimuli-sensitive polymer gel is disposed in the vicinity of the transparent electrode. Moreover, the optical element has at least the stimuli-sensitive polymer gel which swells or shrinks by an external stimulus and has redox ability, and a liquid absorbable in the stimuli-sensitive polymer gel between the oxidation reduction electrodes having the transparent electrode and redox ability, and the stimuli-sensitive polymer gel is brought into contact with the transparent electrode. The modulation method controls the redox state of the stimuli- sensitive polymer gel to control the swelling or the shrinking of the stimuli- sensitive polymer gel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical element and a modulation method capable of controlling the amount of light scattering, the amount of reflection, the amount of light absorption, and the like in accordance with an electric signal, and more particularly to a color display element for displaying images, characters, and the like. The present invention relates to a variable color filter, a light control element, a light control glass, an optical element usable for an interior or a building material, and a modulation method.

[0002]

2. Description of the Related Art An optical element technology utilizing a volume change of a polymer gel is disclosed in Japanese Patent Application Laid-Open Nos. 61-149926 and 61-149926.
-274480. Many of these techniques change the pH of a solution near an electrode by energization to make a polymer electrolyte gel respond. However, since such a pH change is caused by electrolysis of the aqueous electrolyte solution by energization, there is a problem that a gas such as hydrogen or oxygen is generated. A driving system using a conductive polymer as an electrode and generating no gas is disclosed in Japanese Patent Publication No. 7-95172 and Japanese Patent Application Laid-Open No. H11-161203.
No. 6,086,045. Next, these techniques will be described.

The display device disclosed in Japanese Patent Publication No. 7-95172 has a structure in which an electrolyte is contained between an insulating substrate and a transparent substrate, and is further divided by partitions to form pixels. ing. A first electrode is formed on the insulating substrate. A conductive polymer film is provided on the first electrode. Further, one or more gels (particles) are fixed on or close to the conductive polymer film.
A second electrode is formed on the transparent substrate. Then, the external voltage signal is applied between the first electrode and the second electrode.

When a positive voltage is applied to the first electrode as an external voltage signal, the conductive polymer film on the first electrode is doped with anions in the electrolyte. When a negative voltage is applied, anions are undoped from the conductive polymer film. Therefore, the anion concentration in the vicinity of the conductive polymer film in the electrolytic solution changes, the osmotic pressure balance of the gel on the conductive polymer film changes, and the gel swells or contracts. The volume of the gel when it swells is several tens of times the volume when it shrinks, and produces an optically apparent difference that can be visually recognized. Further, in order to sharpen the optical difference, a coloring liquid in which a dye is dissolved or dispersed may be included in the electrolytic solution.

In the display device disclosed in Japanese Patent Application Laid-Open No. H11-161203, a transparent substrate, which is a display-side substrate, is disposed facing a white substrate, and an electrolytic solution is interposed between the white substrate and the transparent substrate. be satisfied. A first conductive film is formed on a white substrate. Further, a plurality of projecting members provided with means for shrinking or swelling the polymer gel are provided.
A second conductive film is formed on the protruding electrode. A polymer gel is fixed on the second conductive film.

[0006] When a voltage is applied between the first conductive film and the second conductive film, the conductive film performs doping and undoping of ions according to the polarity of the applied voltage. The polymer gel can be shrunk or swelled by changing the pH of the nearby electrolyte. It describes that the polymer gel at the time of contraction cannot be visually recognized, but the hue of the polymer gel can be recognized at the time of swelling.

In the optical element disclosed in Japanese Patent Publication No. 7-95172, a material having an ion doping / dedoping ability (conductive polymer or the like) is formed only on one electrode.
The counter electrode has a configuration in which a material having a redox ability is not formed.

[0008] For this reason, in the case of an oxidation-reduction reaction occurring on an electrode having redox ability, the electrode having no oxidation-reduction ability is kept electrically neutral with an electrode having no redox ability. Thus, there is a problem that electrons are exchanged with each other, and the electrolytic solution is electrolyzed and bubbles are generated on the electrodes.

In this optical element, the polymer gel is manufactured by fixing a polymer gel on a conductive polymer electrode. However, most of the conductive polymer do not have an active group necessary for adhesion. It is difficult to stably immobilize a polymer gel on a conductive polymer.

Further, in order to increase the response of the polymer gel, it is required to increase the amount of ion doping / de-doping by a conductive polymer or the like. However, due to the inherent color of the conductive polymer, increasing the film thickness is restricted due to the optical characteristics of the optical element, and there is a problem that the amount of ion doping / undoping cannot be increased.

As disclosed in Japanese Patent Application Laid-Open No. 11-161203, an optical element in which a polymer gel is provided on a protruding conductive polymer electrode can also be fixed on the electrode. Since it is required from the viewpoint of the stability of the dimming repetition, there is a problem in the fixing process as in the above publication.

[0012]

SUMMARY OF THE INVENTION The present invention solves the problems of the prior art, has a large variation in light scattering, reflectance, light absorption, etc., has a stable repetition characteristic, and is novel. An object of the present invention is to provide an optical element and a modulation method which are easy to manufacture.

[0013]

The above object is achieved by the present invention described below. That is, the present invention provides: <1> a stimulus-responsive polymer gel having at least swelling or contracting by an external stimulus and having a redox ability between a transparent electrode and a redox electrode having a redox ability; A liquid that can be absorbed by the stimulus-responsive polymer gel, wherein the stimulus-responsive polymer gel is disposed near the transparent electrode.

<2> A stimulus-responsive polymer gel that swells or contracts by an external stimulus and has a redox ability, at least between a transparent electrode and a redox electrode having a redox ability; A liquid that can be absorbed by the polymer gel, wherein the stimulus-responsive polymer gel is in contact with the transparent electrode.

<3> The optical element according to <1> or <2>, wherein the stimulus-responsive polymer gel swells or contracts due to an oxidation-reduction reaction. <4> The optical element according to any one of <1> to <3>, wherein a light-shielding layer is formed on the surface of the redox electrode.

<5> The stimulus-responsive polymer gel is obtained by crosslinking at least a polymer compound having a functional group having a redox ability. <1> to <4>
> The optical element according to any one of the above.

<6> An interpenetrating network structure in which the stimulus-responsive polymer gel is formed by at least a crosslinked polymer compound having a functional group having a redox ability and another crosslinked polymer compound. <1
> To <4>.

<7> The optical element according to <5> or <6>, wherein a charge state of the functional group is changed by an oxidation-reduction reaction of the functional group having a redox ability.

<8> The ionic concentration of a liquid that can be absorbed by the stimulus-responsive polymer gel is changed by the redox reaction of the functional group having the redox ability. <5> or <6> An optical element according to the item (1).

<9> The stimuli-responsive polymer gel contains a light control material, <1> to <8>.
> The optical element according to any one of the above.

<10> The light modulating material is contained in the stimulus-responsive polymer gel at a concentration of at least a saturated absorption concentration or a saturated scattering concentration at the time of contraction of the stimulus-responsive polymer gel. The optical element according to <9>, wherein

<11> The optical element according to any one of <1> to <10> is energized to control the oxidation-reduction state of the stimuli-responsive polymer gel, thereby swelling the stimuli-responsive polymer gel. , A contraction method.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION The optical element of the present invention swells or contracts at least by an external stimulus between a transparent electrode and a redox electrode having a redox ability, and has a responsiveness to a stimulus having a redox ability. A polymer gel, and a liquid that can be absorbed by the stimulus-responsive polymer gel, wherein the stimulus-responsive polymer gel is disposed near the transparent electrode or is in contact with the transparent electrode. are doing.

FIG. 1 shows a schematic structure of one example of the optical element of the present invention. The optical element includes a stimulus-responsive polymer gel 5 having an oxidation-reduction ability between a transparent electrode 1 and an oxidation-reduction electrode 2 having a material having an oxidation-reduction ability (an oxidation-reduction layer 4) formed on the surface of the electrode 3. And a liquid 6 that can be absorbed in the stimulus-responsive polymer gel 5. The stimulus-responsive polymer gel 5 is in contact with the transparent electrode 1. Further, spacers (particles) 7 are provided in order to provide a certain interval between the electrode substrates.

Stimuli-responsive polymer gel 5 placed between electrodes
Preferably swells or contracts by an oxidation-reduction reaction. The optical density changes according to the swelling or shrinking state.
The stimulus-responsive polymer gel 5 is disposed near the transparent electrode 1 or in contact with the surface of the transparent electrode 1 so that electrons can be exchanged with the transparent electrode 1 by energization.

When the optical element is energized, the stimulus-responsive polymer gel 5 disposed or in contact with or in contact with the transparent electrode 1 is oxidized or reduced by the exchange of electrons with the transparent electrode 1 and is oxidized or reduced. Swells or shrinks depending on the reducing state. At this time, in the opposing redox electrode 2, the redox layer 4 exchanges electrons with the electrode 3, and an oxidation or reduction reaction occurs.

In such an optical element, the redox electrode 2
Electrons are exchanged on both electrodes through the stimulus-responsive polymer gel 5 having a redox ability. Therefore, there is no exchange of electrons accompanying the electrolysis of the liquid 6, the electrical neutral state of the entire optical element can be maintained, and the stimulus-responsive polymer gel 5 can be swollen or contracted.

Since the stimulus-responsive polymer gel 5 greatly changes the optical density according to the swelling or shrinking state,
In the optical element of the present invention, the electrolysis of the liquid 5 does not occur by energization, and the optical density can be largely changed.

The transparent electrode 1 is a current-transmitting electrode having light transmissivity, and preferably comprises at least a substrate member and a current-carrying member. As the substrate member, polyester, polyimide, polymethyl methacrylate, polystyrene, polypropylene, polyethylene, nylon, polyvinyl chloride, polyvinylidene chloride, polycarbonate, a cellulose derivative, a polymer film or substrate such as polyolefin, a glass substrate and the like are preferable. Used.

As the current-carrying member, those forming a metal oxide layer represented by tin oxide-indium oxide (ITO), tin oxide, zinc oxide and the like are preferably used. As the transparent electrode 1, a transparent electrode having a light transmittance of at least 50% or more is preferably used.

It is necessary that the stimulus-responsive polymer gel 5 is disposed near the transparent electrode 1 or is in contact with the transparent electrode 1. If the electrode is too far from the transparent electrode 1, electrons cannot be exchanged with the stimuli-responsive polymer gel 5 having redox ability, and the electrolyte (liquid 6) will be decomposed.
Here, “near” means a distance away from the transparent electrode 1 to such an extent that the electrolyte (liquid 6) is not decomposed by applying a voltage, and more specifically, 0 to 500 μm from the surface of the transparent electrode 1.
Preferably 0 to 100 μm, more preferably 0 to 50 μm
It means up to a distance of about m.

In order to bring the stimulus-responsive polymer gel 5 into contact with the transparent electrode 1, a layer having an active reactive group such as a silane layer is provided on the surface of the transparent electrode 1, and the surface of the layer and the stimulus-responsive polymer What is necessary is just to make the gel 5 react. By providing such a layer, it is difficult to fix the stimulus-responsive polymer gel 5 as in the prior art (refer to Japanese Patent Publication No. 7-95172).
The stimulus-responsive polymer gel 5 can always be stably contacted with the surface of the transparent electrode 1 without fixing on the protruding electrode (Japanese Patent Publication No. 7-95172).

In order to arrange the stimulus-responsive polymer gel 5 in the vicinity of the transparent electrode 1, an electrolytic solution containing the stimulus-responsive polymer gel 5 (liquid 6) is provided between the transparent electrode 1 and the redox electrode 2. ) May be injected and settled down on the electrode.

The redox electrode 2 preferably has at least a redox layer 4 formed of a material having a redox ability on the surface of the electrode 3. As a member for the electrode 3, a metal layer represented by copper, aluminum, gold, silver, nickel, platinum, etc .; tin oxide-indium oxide (IT
O) layer, a metal oxide layer represented by a tin oxide layer; an electrode layer such as a composite material layer of a non-conductive polymer and the above-mentioned metal or metal oxide particles; and the like are preferably used.

The material for forming the redox layer 4 is a material that adsorbs (dopes) or releases (undopes) ions of the liquid 6 filled between the substrates during oxidation and reduction. Inorganic compounds, conductive polymers, and the like applied to electrochromic materials and the like can be preferably used.

The inorganic compounds include lead compounds, manganese compounds, nickel compounds, silver compounds, cadmium compounds, iron compounds, zinc compounds, cobalt compounds, chromium compounds, aluminum compounds, lithium compounds, metal hydrides, tungsten compounds, molybdenum compounds. , Vanadium compounds, indium compounds and the like.

Examples of the conductive polymer include trans-polyacetylene, polypyrrole, polythienylpyrrole, polythiophene, poly (3-methylthiophene), polythienylenevinylene, polyaniline, polyparaphenylene,
Polypyrene, polyazulene, polyfluorene, polyphenylenevinylene, 2,5-diethoxyphenylenevinylene, polyphenylene oxide, polyphenylene sulfide, polynaphthalenevinylene, polyperinaphthalene, polyacrylonitrile, polyoxadiasol, polyacene, poly [Fephthalocyanine (tetrazine) ]
And the like.

As a method of providing such a redox layer 4 made of a metal compound or a conductive polymer on a part of the electrode 3, a chemical, electrochemical, or the like applied in manufacturing an electrode for a secondary battery can be used. Alternatively, a method of depositing these materials on the electrode substrate by a thermal operation, a sputtering method, a vapor deposition method, or the like can be applied.

The oxidation-reduction layer 4 may be formed on the side surface of the projection 11 of the uneven electrode 3 'as shown in FIG. The method of manufacturing the uneven electrode 3 ′ includes, for example, forming an uneven structure on a light-transmitting substrate member by a known method, and forming a conductive layer on the upper surface of the convex portion 11 and the side surface of the convex portion 11. At least a portion of the convex portion on a substrate that has been formed, or a substrate that has a convex electrode formed at a desired portion using a flat substrate having a conductive layer (another electrode, wiring, etc.) formed at a desired portion. A method of forming the oxidation-reduction layer 4 by an electrochemical method, and the like can be given. In such a configuration, the redox electrode 2 can transmit light, so that the optical element of the present invention is of a light transmission type. If the area of the upper surface of the projection 11 is small, the oxidation-reduction layer 4 may also be formed on the upper surface of the projection 11.

Further, as shown in FIG.
It is preferable that the light-shielding layer 8 is formed on the surface. The conductive polymer or the like adopted as a material for the redox layer 4 often has a unique color. No longer be affected by the color of the image. Therefore, a high optical property change can be obtained according to the swelling or shrinking of the stimulus-responsive polymer gel 5.

The material used for the light-shielding layer 8 is preferably made of a transparent material having a high light-scattering property. Specifically, a material composed of a porous membrane or a fibrous membrane as described below, or a composite membrane formed of a membrane in both forms is exemplified. As a method for forming the light-shielding layer 8 on the surface of the redox electrode 2, a porous film, a fibrous film, or a composite film thereof is adhered to the surface of the electrode 3 with an adhesive or the like, or directly formed by a casting method or the like. Can be performed. If a porous membrane, a fibrous membrane, or a composite membrane of these can be brought into close contact with the surface of the redox electrode 2, a step of bonding with an adhesive or the like may not be necessary.

By adjusting the thickness of the porous film, the fibrous film or the composite film thereof, the thickness of the light-shielding layer 8 can be reduced to 0.5%.
It is preferable to set the range of μm to 1 mm. Light shielding layer 8
When the thickness is less than 0.5 μm, the light scattering property decreases,
In some cases, the color of the redox layer 4 cannot be hidden. 1m
When m exceeds m, doping and dedoping of ions in the electrolytic solution to the oxidation-reduction layer 4 due to energization may not be performed efficiently.

Examples of the porous film on which the light-shielding layer 8 can be formed include a stretching method, a two-phase separation method such as a phase change method, a melt cooling method and a polymerization phase separation method, an etching method, and a low molecular extraction method. Extraction methods such as a method, a foaming method such as a blowing agent charging method, a gas injection method, and a mechanical stirring method, a sintering method, a dew condensation method, and various film-like materials prepared by a sol-gel method.

Particularly preferred membranes include, for example, a polytetrafluoroethylene porous membrane in the stretching method, and a cross-linkable polymerizable polymer disclosed in JP-A-10-7835 in the two-phase separation method. Examples thereof include a porous film made of a vinyl monomer, and a polycarbonate film having a large number of through-holes by a phase change method disclosed in Japanese Patent Application Laid-Open No. 9-132667. In addition, in the low-molecular extraction method, a microporous material disclosed in JP-A-10-158429 and the like can be mentioned. In the sol-gel method, ultrafine particles disclosed in JP-A-6-145410 and the like can be used. Dispersed porous materials are exemplified. Furthermore, various porous membranes such as a polypropylene porous membrane, a polyamide porous membrane, a polysulfone porous membrane, and a polyethylene porous membrane which are applied as a separator of a secondary battery can also be preferably used.

These porous films are preferably colorless from the viewpoint of the light control effect of the stimuli-responsive polymer gel 5, but a colored porous film may be used depending on the purpose. Since the light scattering effect (hiding effect) of the porous film is preferably high, a porous film having an average pore diameter in the range of 0.05 to 500 μm, preferably 0.1 to 100 μm is applied. It is also preferable to use a porous film containing a white pigment or the like.

Examples of the fibrous film that can be used as the light-shielding layer 8 include a mere fiber aggregate, a knitted fabric, a net shape, or a woven fabric obtained by knitting a yarn obtained by twisting fibers. Non-woven fabrics in which fibers are partially fused or entangled with each other, such as a film.

The fibers constituting the fibrous membrane include, for example, synthetic fibers such as nylon fibers, acrylic fibers, polyester fibers, polypropylene fibers, polyvinyl chloride fibers, polyamide fibers, and polyurethane fibers; Natural fibers such as wood pulp and cotton and wool; semi-synthetic fibers such as viscose rayon, acetate and cupra; and inorganic fibers such as carbon fiber, titanium fiber and glass fiber. In particular, a fibrous membrane composed of synthetic fibers and semi-synthetic fibers is preferable. Further, a polyethylene nonwoven fabric, a polyamide nonwoven fabric, a polypropylene nonwoven fabric, a polyolefin nonwoven fabric, and the like, which are used as separators for secondary batteries, are also preferable.

The fibers constituting the fibrous membrane are preferably colorless from the viewpoint of the light control effect, similarly to the porous membrane, but colored fibers may be used depending on the purpose. Since the light scattering effect (hiding effect) of the fibrous membrane is preferably high,
Fiber diameter is in the range of 0.1 to 500 μm, preferably 0.2
Use a fibrous membrane in the range of １００100 μm. Further, it is also preferable to apply a fibrous film containing a white pigment or the like.

The light-shielding layer 8 may be colored as shown in FIG. In this case, it is preferable that the electrode portions of the transparent electrode 1 and the redox electrode 2 are formed in a pattern. By patterning the electrodes and applying a current to a specific pattern (segment) electrode 3 ″, the light modulating material of the electrode portion can be changed. As each pattern, any of a division drive type pattern such as a segment and a stripe type can be selected. Further, a driving TFT (thin film transistor) or MIM (Metal)
It is also possible to provide a switching element such as / Insulator / Metal) on the substrate.

Red (R), green (G), and blue (B) light-shielding layers 8a, 8b, and 8c are formed on the surface of the oxidation-reduction layer 4, and the red (R), green (G), Blue (B) light-shielding layer 8
A color image can be displayed by changing the swelling state of the stimulus-responsive polymer gel 5 in contact with the surface of the pattern electrode 1 'of the transparent electrode 1 facing each of a, 8b and 8c. That is, with the configuration shown in FIG. 4, an optical element (color display element) capable of forming a color image can be obtained.

FIG. 4 shows a configuration in which a plurality of stimuli-responsive polymer gels 5 are arranged in contact with one pattern electrode, but one stimulus-responsive polymer gel is applied to one pattern electrode 1 '. The molecular gels 5 may be arranged correspondingly.

The liquid 6 to be filled between the electrodes used in the present invention is required to be a liquid capable of absorbing the stimulus-responsive polymer gel 5, and it is necessary to swell the stimulus-responsive polymer gel 5. Possible liquids are preferred. In particular,
Water; an aqueous electrolyte solution of potassium hydroxide, sodium hydroxide, lithium hydroxide, sodium chloride, potassium chloride, etc .;
Alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol, and butyl alcohol; acetone,
Ketones such as methyl ethyl ketone; esters; ethers; dimethylformamide, dimethylacetamide,
Dimethyl sulfoxide, acetonitrile, propylene carbonate and the like; aromatic solvents such as xylene and toluene and mixtures thereof are preferable. Further, a preferable mixing ratio of the liquid 6 and the stimulus-responsive polymer gel 5 (stimulus-responsive polymer gel: liquid) is 1: 2000 to 1: by weight ratio.
It is one.

The stimulus-responsive polymer gel 5 is preferably a stimulus-responsive polymer gel that absorbs or releases the liquid 6 and changes its volume (swells or contracts) by an oxidation-reduction reaction caused by energization. Further, it is preferable that the ion concentration of the liquid 6 that can be absorbed by the stimulus-responsive polymer gel 5 be changed by the oxidation-reduction reaction.

Examples of the stimuli-responsive polymer gel 5 include a crosslinked product of a compound having a group whose charge state (valence) changes due to a redox reaction and a compound whose solubility changes depending on temperature. Compounds in which a crosslinked body of a polymer compound having a group whose charge state changes due to a redox reaction and a crosslinked body of a polymer compound whose solubility or the like changes with temperature form an interpenetrating network structure, etc. preferable.

Further, a crosslinked product of a compound having a group capable of dissociating ions by an oxidation-reduction reaction and a compound having an ionizable group, and a crosslinked product of a polymer compound having a group capable of dissociating an ion by a redox reaction, A compound in which a crosslinked product of a polymer compound having an ionizable group forms an interpenetrating network structure is also preferable.

Specific examples of the compound having a group whose charge state changes by an oxidation-reduction reaction include at least one selected from a vinyl-substituted ferrocene derivative, a vinyl-substituted nicotinamide derivative, a vinyl-substituted pyridine derivative, and a viologen derivative. No.

Specific examples of the polymer compound whose solubility or the like changes depending on the temperature include N-alkyl-substituted (meth) acrylamides such as N-isopropylacrylamide, N-isopropylacrylamide and the like.
Selected from alkyl-substituted (meth) acrylamide and (meth) acrylic acid and salts thereof, (meth) acrylamide, alkyl (meth) acrylate, vinyl methyl ether, and alkyl-substituted cellulose derivatives such as methyl cellulose, ethyl cellulose, and hydroxypropyl cellulose. Or more.

A compound in which a crosslinked polymer having a group whose charge state changes by an oxidation-reduction reaction and a polymer crosslinked whose solubility and the like change depending on temperature forms an interpenetrating network structure (hereinafter, referred to as a compound). The “interpenetrating network structure” is sometimes referred to as) a cross-linked body of a polyvinyl-substituted ferrocene derivative, a cross-linked body of a polyvinyl-substituted nicotinamide derivative, a cross-linked body of a polyvinyl-substituted pyridine derivative, and poly-N- Crosslinked product of poly N-alkyl-substituted (meth) acrylamide such as isopropylacrylamide, crosslinked product of poly N-alkyl-substituted (meth) acrylamide and (meth) acrylic acid or a salt thereof, poly (meth) acrylamide, poly (meth) acryl Acid alkyl esters, polyvinyl methyl ether, polymethyl cellulose, polyethyl cellulose Scan, and any one or more of the crosslinked products such as an alkyl-substituted cellulose derivatives such as poly hydroxypropyl cellulose, interpenetrating network structure or the like made of the like.

Examples of the polymer compound having a group capable of dissociating ions by a redox reaction include vinyl-substituted pyrazoloquinone derivatives, vinyl-substituted thiol derivatives, vinyl-substituted hydroquinone derivatives, vinyl-substituted naphthoquinone derivatives, vinyl-substituted anthraquinone derivatives, vinyl-substituted isoalloxazine derivatives, At least one or more compounds selected from compounds having a group capable of dissociating ions by an oxidation-reduction reaction, such as a vinyl-substituted phenothiazine derivative, are exemplified.

Examples of the polymer compound having an ionizable group include (meth) acrylic acid or a salt thereof; (meth) acrylic acid, (meth) acrylamide, hydroxyethyl (meth) acrylate, and alkyl (meth) acrylate. Or a salt thereof with any one or more of maleic acid and (meth) acrylamide, hydroxyethyl (meth) acrylate, alkyl (meth) acrylate, etc. Its salt;

Copolymers of polyvinyl sulfonic acid or vinyl sulfonic acid with (meth) acrylamide, hydroxyethyl (meth) acrylate, alkyl (meth) acrylate, etc., and at least one of vinyl benzene sulfonic acid and a salt thereof Vinyl benzene sulfonic acid;
Copolymers and salts thereof with any one or more of (meth) acrylamide, hydroxyethyl (meth) acrylate, alkyl (meth) acrylate and the like; acrylamidoalkylsulfonic acid and its salts; acrylamidoalkylsulfonic acid and (meth) Copolymer with any one or more of acrylamide, hydroxyethyl (meth) acrylate, alkyl (meth) acrylate and the like; and dimethylaminopropyl (meth) acrylamide and its hydrochloride; dimethylaminopropyl (meth) acrylamide And a copolymer of any one or more of (meth) acrylic acid, (meth) acrylamide, hydroxyethyl (meth) acrylate, and alkyl (meth) acrylate, and salts and hydrochlorides thereof; dimethylaminopropyl (meth) ) Acrylamide, Complex with vinyl alcohol and its hydrochloride; Copolymer of vinyl alcohol and (meth) acrylic acid, its salt, carboxyalkylcellulose salt, partially hydrolyzed product of (meth) acrylonitrile and its salt A crosslinked product of a copolymer with at least one or more types of electrolyte polymer that responds to changes in ion concentration, such as a crosslinked product of the above. In addition, "(meta)" means including the compound name in parentheses (the same applies hereinafter).

Compounds in which a crosslinked product of a polymer compound having a group capable of dissociating ions by an oxidation-reduction reaction and a crosslinked product of a polymer compound having an ionizable group form an interpenetrating network structure include: Crosslinked product of polyvinyl substituted pyrazoloquinone derivative, crosslinked product of polyvinyl substituted thiol derivative, crosslinked product of polyvinyl substituted hydroquinone derivative, crosslinked product of polyvinyl substituted naphthoquinone derivative, crosslinked product of polyvinyl substituted anthraquinone derivative, crosslinked product of polyvinyl substituted isoalloxazine derivative, polyvinyl substitution A crosslinked product of at least one selected from a crosslinked product having a group capable of dissociating ions by a redox reaction such as a crosslinked product of a phenothiazine derivative and poly (meth) acrylic acid, or a salt thereof;

Crosslinked product of (meth) acrylic acid and any one or more of (meth) acrylamide, hydroxyethyl (meth) acrylate, alkyl (meth) acrylate and the like, and salts thereof; , (Meta)
Crosslinked product of a copolymer with any one or more of acrylamide, hydroxyethyl (meth) acrylate, alkyl (meth) acrylate and the like, and a salt thereof; Crosslinked product of polyvinylsulfonic acid and vinylsulfonic acid, and (meth) acrylamide , Hydroxyethyl (meth) acrylate,
A crosslinked product of a copolymer with any one or more of alkyl (meth) acrylates and the like; a crosslinked product of polyvinylbenzenesulfonic acid and a salt thereof;

A crosslinked product of a copolymer of vinylbenzene sulfonic acid and one or more of (meth) acrylamide, hydroxyethyl (meth) acrylate, alkyl (meth) acrylate and the like, and salts thereof; polyacrylamide alkyl sulfone Cross-linked products of acids and salts thereof; acrylamidoalkylsulfonic acid and (meth) acrylamide,
Crosslinked product of a copolymer with any one or more of hydroxyethyl (meth) acrylate and alkyl (meth) acrylate and salts thereof; Crosslinked product of polydimethylaminopropyl (meth) acrylamide and hydrochloride thereof; dimethylamino A cross-linked product of a copolymer of propyl (meth) acrylamide with one or more of (meth) acrylic acid, (meth) acrylamide, hydroxyethyl (meth) acrylate, alkyl (meth) acrylate, and a salt thereof; Hydrochloride; cross-linked product of a complex of polydimethylaminopropyl (meth) acrylamide and polyvinyl alcohol and its hydrochloride; polyvinyl alcohol and poly (meth)
Interpenetrating network with at least one selected from a crosslinked product of a complex with acrylic acid and a salt thereof, a crosslinked product of a carboxyalkylcellulose salt, a partially hydrolyzed product of a crosslinked product of poly (meth) acrylonitrile, a salt thereof and the like. Structure.

The stimulus-responsive polymer gel 5 preferably contains a light modulating material. By using a colored stimulus-responsive polymer gel containing a light modulating material in the stimulus-responsive polymer gel 5 described above,
In accordance with the swelling or shrinking of the polymer, a higher change in optical properties can be obtained. Materials for light control include dyes, pigments,
Light scattering materials and the like can be used.

Specific examples of the dye include azo dyes which are black nigrosine dyes and color dyes such as red, green, blue, cyan, magenta and yellow, anthraquinone dyes, indigo dyes, phthalocyanine dyes, and the like. Carbonium dyes, quinone imine dyes, methine dyes, quinoline dyes, nitro dyes, benzoquinone dyes, naphthoquinone dyes, naphthalimide dyes, verinone dyes, and the like,
In particular, those having a high light absorption coefficient are preferable.

For example, C.I. I. Direct Yellow 1,
8, 11, 12, 24, 26, 27, 28, 33, 3,
9, 44, 50, 58, 85, 86, 87, 88, 8
9, 98, 157, C.I. I. Acid Yellow 1, 3,
7, 11, 17, 19, 23, 25, 29, 38, 4
4, 79, 127, 144, 245; I. Basic yellow 1, 2, 11, 34; I. Food yellow 4; I. Reactive Yellow 37; C.I. I.
Solvent Yellow 6, 9, 17, 31, 35, 10
0, 102, 103, 105; I. Direct Red 1, 2, 4, 9, 11, 13, 17, 20, 23, 2
4, 28, 31, 33, 37, 39, 44, 46, 6
2, 63, 75, 79, 80, 81, 83, 84, 8
9, 95, 99, 113, 197, 201, 218, 2
20, 224, 225, 226, 227, 228, 22
9, 230, 231; I. Acid Red 1, 6,
8, 9, 13, 14, 18, 26, 27, 35, 37,
42, 52, 82, 85, 87, 89, 92, 97, 1
06, 111, 114, 115, 118, 134, 15
8, 186, 249, 254, 289,

C. I. Basic Red 1, 2, 9, 1
2, 14, 17, 18, 37; C.I. I. Food red 1
4; I. Reactive Red 23, 180; C.I.
I. Solvent Red 5, 16, 17, 18, 19, 2
2, 23, 143, 145, 146, 149, 150,
151, 157, 158; I. Direct Blue 1, 2, 6, 15, 22, 25, 41, 71, 76, 7
8, 86, 87, 90, 98, 163, 165, 19
9, 202; I. Acid Blue 1, 7, 9, 2
2, 23, 25, 29, 40, 41, 43, 45, 7
8, 80, 82, 92, 93, 127, 249;
I. Basic Blue 1, 3, 5, 7, 9, 22, 2
4, 25, 26, 28, 29; I. Food blue 2; I. Solvent Blue 22, 63, 78, 83
-86, 191, 194, 195, 104; I. Direct Black 2, 7, 19, 22, 24, 32, 3
8, 51, 56, 63, 71, 74, 75, 77, 10
8, 154, 168, 171; I. Acid Black 1, 2, 7, 24, 26, 29, 31, 44, 48,
50, 52, 94; I. Basic Black 2,
8; I. Food black 1, 2; I. Reactive black 31; I. Food violet 2;
C. I. Solvent violet 31, 33, 37;
C. I. Solvent Green 24, 25; C.I. I. Solvent Brown 3, 9; and the like. These dyes may be used alone or in combination with other dyes or pigments described below in order to obtain a desired color.

On the other hand, examples of the pigment include various carbon blacks (such as channel black and furnace black) as black pigments, metal oxides such as titanium oxide as white pigments, and color pigments. Examples of the color pigment include a phthalocyanine cyan pigment, a benzidine yellow pigment, a rhodamine magenta pigment, and other anthraquinone, azo, azo metal complex, phthalocyanine, quinacridone, perylene, and indigo. And various color pigments such as isoindolinone type, quinacridone type and allylamide type.

For example, compounds represented by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds and allylamide compounds are used as yellow pigments. More specifically,
C. I. Pigment Yellow 12, 13, 14, 15,
17, 62, 74, 83, 93, 94, 95, 109,
110, 111, 128, 129, 147, 168 and the like are preferably used.

The magenta pigments include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, lake pigments, naphthol compounds, benzimidazolone compounds, thioindigo compounds,
A perylene compound is used. More specifically, C.I. I.
Pigment Red 2, 3, 5, 6, 7, 23, 48:
2, 48: 3, 48: 4, 57: 1, 81: 1, 14
4, 146, 166, 169, 177, 184, 18
5, 202, 206, 220, 221, 254 are particularly preferred.

As the cyan pigment, copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, lake pigments and the like can be used. Specifically, C.I. I. Pigment Blue 1, 7, 15, 15: 1, 15: 2, 15: 3,
15: 4, 60, 62, 66, etc. can be used particularly preferably.

As more specific examples of the white pigment or the light scattering material, zinc oxide, basic lead carbonate, basic lead sulfate, lead sulfate, lithopone, muscovite, zinc sulfide, titanium oxide, ammonium oxide, lead white, Zirconium oxide, alumina, mycanite, mycarex, quartz, calcium carbonate,
Gypsum, clay, silica, silicic acid, silicon earth, talc, basic magnesium carbonate, alumina white, gloss white, satin white and other inorganic oxides; zinc, alumel, antimony, aluminum, aluminum alloy, iridium,
Indium, osmium, chromium, chromel, cobalt, zirconium, stainless steel, gold, silver, nickel silver, copper,
Bronze, tin, tungsten, tungsten steel, iron, lead,
Nickel, nickel alloy, nickeline,

Metals such as platinum, platinum rhodium, tantalum, duralumin, nichrome, titanium, Krupp austenitic steel, constantan, brass, platinum iridium, palladium, palladium alloy, molybdenum, molybdenum steel, manganese, manganese alloy, rhodium, rhodium alloy, etc. Materials: phenolic resin, furan resin, xylene / formaldehyde resin, urea resin, melamine resin, aniline resin, alkyd resin, unsaturated polyester, epoxy resin, polyethylene, polypropylene, polystyrene, poly-p-xylylene, polyvinyl acetate, acrylic resin ,
Methacrylic resin, polyvinyl chloride, polyvinylidene chloride, fluoroplastic, polyacrylonitrile, polyvinyl ether, polyvinyl ketone, polyether,
Materials composed of polycarbonate, thermoplastic polyester, polyamide, diene plastic, polyurethane plastic, polyphenylene, polyphenylene oxide, polysulfone, aromatic heterocyclic polymer, silicone, natural rubber plastic, cellulosic plastic and other high polymer materials And the like.

The particle size of the light control material such as a pigment used is 0.001 μm to 1 μm in terms of the volume average particle size of the primary particles.
Is preferred, and more preferably 0.01 μm to 0.5 μm. If the volume average particle size is less than 0.001 μm, it will easily flow out of the stimuli-responsive polymer gel, and if it exceeds 1 μm, the coloring properties may be deteriorated.

The light modulating material is contained in the stimulus-responsive polymer gel 5 and must not flow out of the stimulus-responsive polymer gel 5. In order to prevent the light control material from flowing out, the crosslink density of the colored polymer gel is optimized and the light control material is physically confined in the polymer network. It is preferable to take measures such as using a light modulating material having a high physical interaction or using a light modulating material whose surface is chemically modified.

For example, when a dye is used as a light control material, a dye having a structure having a polymerizable group such as an unsaturated double bond group or a so-called reactive dye capable of reacting with the stimulus-responsive polymer gel 5 is used. Are preferably used. When a pigment is used as a light control material, a material having a surface into which a group that chemically bonds to a stimulus-responsive polymer gel 5 such as an unsaturated group such as a vinyl group or an unpaired electron (radical) is introduced. Pigments grafted with a polymer material and the like are preferably used.

When the stimulus-responsive polymer gel 5 shrinks, the light modulating material has a concentration at least equal to or higher than the saturation absorption concentration (in the case of a light scattering material, equal to or higher than the saturation scattering concentration). Is preferably contained.

Here, “above the saturation absorption concentration (above the saturation scattering concentration)” means the relationship between the density of the light control material and the optical density (or the amount of light absorption or light scattering) under a specific optical path length. Indicates a region having a high light-modulating material concentration that is largely separated from the relationship of the primary straight line.

The concentration of the light control material to be contained in the stimulus-responsive polymer gel 5 depends on the light absorption coefficient of the light control material in order to make the concentration higher than the saturation absorption concentration or the saturation scattering concentration. Generally, 3 to 90% by weight is preferable, and 5 to 8% by weight.
0% by weight is more preferred.

If the concentration of the light modulating material is less than 3% by weight, the saturation absorption concentration does not exceed the saturation absorption concentration, and the change in volume of the stimulus-responsive polymer gel 5 causes a sufficient change in reflectance or light absorption. The amount may not appear. If it exceeds 90% by weight, the stimulus response characteristics and volume change of the stimulus-responsive polymer gel 5 may be reduced.

The stimuli-responsive polymer gel 5 containing such a light modulating material is prepared by uniformly dispersing and mixing the light modulating material in the polymer before cross-linking, followed by cross-linking, or a polymer precursor monomer during polymerization. It can be produced by a method of adding a dimming material to the composition and polymerizing the composition.

When a light modulating material is added at the time of polymerization, it is preferable to use a light modulating material having a polymerizable group or an unpaired electron (radical) as described above, and to form a chemical bond.

It is preferable that the light control material is dispersed as uniformly as possible in the stimulus-responsive polymer gel 5. In particular, at the time of dispersion in the stimulus-responsive polymer gel 5, it is preferable to uniformly disperse by using a mechanical kneading method, a stirring method, or a dispersant. The shape of the stimulus-responsive polymer gel 5 may be spherical, cubic, elliptical, polyhedral, porous, fibrous, star-like, needle-like, hollow, or the like.

The preferred size of the stimuli-responsive polymer gel 5 is 0.1 μm in volume average particle size in the contracted state.
５5 mm, more preferably 1１〜500 μm. If the volume average particle diameter is less than 0.1 μm, problems such as difficulty in handling the stimuli-responsive polymer gel 5 and failure to obtain excellent optical properties may occur. If the volume average particle size is larger than 5 mm, there arises a problem that the time required for the volume change required for the stimuli-responsive polymer gel 5 may be significantly increased.

The particles of the stimulus-responsive polymer gel 5 can be obtained by pulverizing the stimulus-responsive polymer gel 5 by a physical pulverization method, or by subjecting the stimulus-responsive polymer gel 5 before crosslinking to a physical pulverization method. Or by a method of crosslinking after forming into particles by a chemical pulverization method, or a general method such as a particle polymerization method such as an emulsion polymerization method, a suspension polymerization method, or a dispersion polymerization method.

Further, in order to make the volume change characteristic of the stimuli-responsive polymer gel 5 faster, the stimuli-responsive polymer gel 5 is made porous to improve the inflow and outflow of liquid, as in the prior art polymer gel. It is also preferable to make it. As a conventional technique, for example, there is a method of freeze-drying the swollen stimuli-responsive polymer gel 5 to make it porous.

The volume change of the stimulus-responsive polymer gel 5 is preferably large. More preferably, it is 15 or more. If the volume ratio is less than 5, the amount of change in reflectance or the amount of change in light absorption may be insufficient.

The color tone and the like can be arbitrarily changed by controlling the swelling and shrinking of the stimuli-responsive polymer gel by applying a current to the optical element having the above-described configuration.

[0090]

The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the present invention is limited thereto.

Example 1 Preparation of Stimuli-Responsive Polymer Gel First, a crosslinked polymer of a polymer having a group whose charge state changes due to an oxidation-reduction reaction was prepared as follows. Note that vinylferrocene was used as a monomer having a group whose charge state changes due to an oxidation-reduction reaction.

10 g of carbon black having a primary particle size of 0.1 μm (volume average particle size) (Showa Cabot Co., Ltd .; Show Black: hereinafter sometimes referred to as “CB”) is used as a surfactant, and Emulgen 909 (made by Kao) as a surfactant. ) Was mixed with 50 ml of distilled water to which 0.3 g was added, and a pigment dispersion solution in which CB was uniformly dispersed was prepared using an ultrasonic dispersing device.

As the monomer species, 3.3 g of N-isopropylacrylamide and 0.2 g of vinyl ferrocene were used.
0.0044 g of N, N'-methylenebisacrylamide (MBA) as a cross-linking agent, 0.1696 g of azobisisobutyronitrile as a polymerization initiator, and 2 g of a CB pigment dispersion solution as a coloring material, in dimethyl sulfoxide. The resultant was dissolved in 3.336 g, and left standing at 60 ° C. for 8 hours under a nitrogen atmosphere to carry out polymerization to prepare a stimuli-responsive polymer gel.

The produced stimuli-responsive polymer gel was pulverized by high-speed stirring for 1 minute by a rotary stirring blade. The pulverized stimulus-responsive polymer gel was sieved with a screening sieve to prepare stimulus-responsive polymer gel particles having a volume average particle size of 50 μm.

—Preparation of Optical Element— Two glass substrates (5 cm × 5 cm × 1 mm, trade name: U film, manufactured by Asahi Glass Co., Ltd.) having an electrode layer of tin oxide formed on the surface are used as electrode substrates for optical elements. And Among these, a transparent electrode was formed from one electrode substrate, and a redox electrode was formed from the other electrode substrate.

On the surface of the tin oxide electrode layer of the redox electrode,
A polypyrrole layer (conductive polymer layer) as described below was provided as a colored electrode, and a porous film was adhered to the surface of the colored electrode as a light-shielding layer.

The polypyrrole layer was formed by using an aqueous pyrrole solution and performing electrolytic polymerization of pyrrole on a redox electrode. Specifically, as a pyrrole aqueous solution, 0.1 mol
1 / l pyrrole and an aqueous solution in which 0.1 mol / l sodium chloride were dissolved were prepared, the working electrode was a redox electrode, the counter electrode was a platinum plate, and the reference electrode (silver / silver chloride) was used. A voltage was applied to the working electrode so that the voltage became 0.9 V, and electrolytic polymerization was performed.

A porous film as a light-shielding layer is disclosed in
It was formed in the following manner by a phase inversion method as described in JP-A-132667 or the like. 14 g of polysulfone,
86 g of dimethylformamide and 10 g of distilled water were mixed and dissolved to prepare a polymer solution. The prepared polymer solution was heated to 40 ° C. A polymer solution at 40 ° C. was heated to 40 ° C. using polyethylene terephthalate (P
ET) cast on a film, and after 2 seconds, immersed in a coagulation bath of methanol at -50 ° C for 60 seconds, and PET in the coagulation bath.
Stripped from film.

Thereafter, the surface (the surface from which the PET film was peeled off) was etched with enzyme plasma to form a porous film. The average pore diameter of this porous membrane was 1 μm, and its thickness was 1 μm. The porous film was adhered to the surface of the polypyrrole layer by bringing the porous film into close contact with the electrode substrate provided with the previously prepared polypyrrole layer and heating it to the glass transition temperature of polysulfone (190 ° C.).

On the other hand, a stimuli-responsive polymer gel was fixed on the surface of the transparent electrode as follows. First, the transparent electrode was surface-treated with a 4 mol / l HCl aqueous solution for 30 minutes, and then immersed in a solution prepared by adding 4 ml of γ-aminopropyltriethoxysilane to 200 ml of an ethanol 95% aqueous solution with stirring for 30 minutes. Was. After immersion, the substrate was lightly washed with methanol and left in an oven at 150 ° C. for 1 hour to form a cured silane layer. On the formed silane layer, after uniformly applying a dispersion solution obtained by dispersing the stimulus-responsive polymer gel particles in an aqueous potassium hydroxide solution,
It was left stationary for 10 hours to immobilize it.

Using a transparent electrode having a stimuli-responsive polymer gel immobilized thereon and an oxidation-reduction electrode having a light-shielding layer formed thereon, an optical element was produced as follows. First, 3 between the electrodes
In order to provide an interval of 00 μm, 300 μm spacer particles were prepared, and the spacer particles were sprayed on the surface of the transparent electrode on which the stimulus-responsive polymer gel was fixed. Thereafter, the surface of the redox electrode on which the light-shielding layer was formed was overlapped so as to face the transparent electrode. Next, the outer peripheral portions of the two superposed electrodes were coated with an ultraviolet curable resin, leaving an opening, cured by irradiating ultraviolet rays, and sealed.

As a liquid that can be absorbed into the stimulus-responsive polymer gel, 0.01 mol / l potassium hydroxide was injected from the above-mentioned opening through a vacuum injection method. After the injection, an ultraviolet curable resin was applied again to the opening, and the opening was sealed by irradiating ultraviolet rays to produce an optical element. At this time, the stimulus-responsive polymer gel is swollen by absorbing the potassium hydroxide aqueous solution. It was found that the entire surface was blackened by the color of the carbon black pigment in the molecular gel.

-Evaluation of Optical Element- The optical element produced above was evaluated as follows. First, the optical element was arranged in an optical density measuring device (manufactured by Xrite). The optical element was wired so that a voltage could be applied using the transparent electrode on which the stimuli-responsive polymer gel was immobilized as the anode and the other redox electrode as the cathode. When a DC voltage of 1.2 V was applied to this wiring, the color of the surface of the optical element on which the stimulus-responsive polymer gel was fixed instantaneously changed from black to almost white. When this color change was evaluated by an optical density measuring device, it was found that the reflection optical density changed from 1.4 to 0.7. When a voltage of opposite polarity was applied, the color of the surface of the optical element on which the stimuli-responsive polymer gel was fixed changed instantaneously and changed from white to black, and the reflection optical density returned to the original value. Although such energization was performed 100 times or more, generation of bubbles due to electrolysis of the swelling liquid of the stimuli-responsive polymer gel was not observed at all, and a stable change in reflection optical density could be obtained.

Example 2 Preparation of Stimuli-Responsive Polymer Gel First, a crosslinked product of a polymer compound having a group capable of dissociating ions by an oxidation-reduction reaction was prepared as follows. In addition,
Vinylhydroquinone was used as a monomer having a group capable of dissociating ions by a redox reaction. The vinyl hydroquinone is available from Makromol. Chem. , 12
3, 223 (1969).

The main monomer is vinylhydroquinone 5
g, methacrylic acid 3.2 g and sodium hydroxide 3 g
, N, N'-methylenebisacrylamide as a crosslinking agent, 0.01 g of tributylborane as a polymerization initiator, and the CB pigment dispersion 10 used in Example 1.
g) was dissolved in 30 g of cyclohexanone, allowed to stand at 35 ° C. for 10 hours under nitrogen substitution to carry out polymerization, to produce a stimuli-responsive polymer gel, and crushed and sieved in the same manner as in Polymerization Example 1. Stimulus-responsive polymer gel particles having a volume average particle size of 50 μm were prepared.

—Preparation of Optical Element— Two glass substrates (5 cm × 5 cm × 1 mm, trade name: U film, manufactured by Asahi Glass Co., Ltd.) having an electrode layer of tin oxide formed on the surface of the electrode substrate of the optical element And Among these, a transparent electrode was formed from one electrode substrate, and a redox electrode was formed from the other electrode substrate.

A silane coupling agent (3-glycidoxypropyltrimethoxysilane) solution was applied to the surface of the tin oxide electrode layer of the transparent electrode, and heated to form a binder layer (silane layer). Then, a paste solution consisting of the stimulus-responsive polymer gel particles and water is prepared, and the paste solution is applied to the surface of the binder layer and heated to chemically react the reactive silane coupling agent and the stimulus-responsive polymer gel. After the reaction, the stimulus-responsive polymer gel particles were immobilized on the surface of the porous membrane.

A transparent electrode having a stimuli-responsive polymer gel immobilized thereon, an oxidation-reduction electrode produced in the same manner as in Example 1,
Was used to produce an optical element as follows. First, in order to provide an interval of 300 μm between the electrode substrates, 3
Prepare spacer particles of 00 μm, the spacer particles,
The stimulus-responsive polymer gel of the transparent electrode was sprayed on the immobilized surface. Thereafter, the surface of the redox layer on which the light-shielding layer was formed was attached so as to oppose the transparent electrode. next,
The outer peripheral portions of the two superposed electrodes were coated with an ultraviolet curable resin, leaving an opening, irradiated with ultraviolet light, cured and sealed.

A 0.001 mol / l aqueous solution of potassium hydroxide was injected from the opening by a reduced pressure injection method as a liquid absorbable into the stimuli-responsive polymer gel. After the injection, an ultraviolet curable resin was applied again to the opening, and the opening was sealed by irradiating ultraviolet rays to produce an optical element.

At this time, the stimuli-responsive polymer gel is swollen by absorbing the potassium hydroxide aqueous solution. When the surface on which the stimuli-responsive polymer gel is fixed is observed from the transparent electrode side, the It was found that the color of the carbon black pigment in the hydrophilic polymer gel was black over the entire surface.

—Evaluation of Optical Element— The optical element produced above was evaluated in the same manner as in Example 1 except that the DC voltage applied to the oxidation-reduction electrode was 1.0 V.
After energization, the color of the surface of the optical element on which the stimuli-responsive polymer gel was immobilized changed instantaneously, and changed from black to almost white. When this color change was evaluated by an optical density measuring device, it was found that the reflection optical density changed from 1.5 to 0.3.
When a voltage of opposite polarity was applied, the color of the surface of the optical element on which the stimuli-responsive polymer gel was fixed changed instantaneously and changed from white to black, and the reflection optical density returned to the original value. Although such energization was performed 100 times or more, generation of bubbles due to electrolysis of the swelling liquid of the stimuli-responsive polymer gel was not observed at all, and a stable change in reflection optical density could be obtained.

(Example 3) -Preparation of stimulus-responsive polymer gel- First, a polymer compound having a group capable of dissociating ions and an electrolyte polymer are cross-linked to form an interpenetrating network structure (IPN body). An IPN gel (stimulus-responsive polymer gel) of polyvinyl hydroquinone and polyacrylic acid was prepared as follows.

A temperature sensor was set in a water bath, and the controller was set at 70 ° C. for heating. At that time, the lower magnetic stirrer was started, and the rotor in the water bath was smoothly rotated. 1.5 g of acrylic acid in a screw tube
, Water 5.5, and 0.0015 g of MBA (N, N'-methylenebisacrylamide), and after sufficient purging with nitrogen, a polymerization initiator APS (ammonium persulfate).
0.006 g was added and mixed uniformly to prepare an acrylic acid solution.

The same CB pigment as in Example 1 and 0.25 g of vinylhydroquinone particles were placed in the acrylic acid solution, sufficiently impregnated, and reacted in a water bath at 70 ° C. for 3 hours. After the reaction, the resultant was poured into pure water and washed, and only a stimulus-responsive polymer gel was separated and collected. The volume average particle diameter of the polymerized IPN gel (stimulus-responsive polymer gel) of polyvinyl hydroquinone and polyacrylic acid was 50 μm.

—Preparation of Optical Element— The prepared stimuli-responsive polymer gel was immobilized on the surface of a transparent electrode in the same manner as in Example 2 to prepare an optical element.

—Evaluation of Optical Element— The optical element produced above was evaluated in the same manner as in Example 2. After energization, the color of the surface of the optical element on which the stimuli-responsive polymer gel was immobilized changed instantaneously, and changed from black to almost white. When this color change was evaluated by an optical density measuring device, it was found that the reflection optical density changed from 1.5 to 0.3. When a voltage of opposite polarity was applied, the color of the surface of the optical element on which the stimuli-responsive polymer gel was fixed changed instantaneously and changed from white to black, and the reflection optical density returned to the original value. Although such energization was performed 100 times or more, generation of bubbles due to electrolysis of the swelling liquid of the colored stimulus-responsive polymer gel was not observed at all, and a stable change in reflection optical density could be obtained.

Comparative Example 1 Preparation of pH-Responsive Polymer Gel (Stimuli-Responsive Polymer Gel without Redox Properties) pH-Responsive Polymer Gels Containing Black Pigment Carbon Black (Redox Properties) Of a stimuli-responsive polymer gel having no) were prepared as follows.

As monomer species, 10 g of acrylic acid,
0.02 g of methylenebisacrylamide as a crosslinking agent
Was dissolved in 20 ml of distilled water, and 6 g of sodium hydroxide was added thereto to prepare an aqueous monomer solution in which acrylic acid was neutralized. This aqueous solution was mixed with the CB dispersion solution prepared in Example 1, and this was placed in a flask, degassed and replaced with nitrogen to prepare a monomer mixture.

A mixture obtained by adding 0.2 g of ammonium persulfate as a polymerization initiator to this monomer mixture was charged into 200 ml of cyclohexane as a dispersion medium, and the mixture was added to a vessel purged with nitrogen and emulsified by high-speed stirring with a homogenizer. . Further, 0.1 ml of tetraethylethylenediamine was added as a polymerization accelerator, and polymerization was performed at 30 ° C. for 5 hours.

Purification was performed by repeatedly charging black particles produced by polymerization into a large amount of distilled water and filtering the same. Thereafter, the particles were dehydrated and dried using a large amount of methanol to prepare particles of a pH-responsive polymer gel.
The particles of the prepared pH-responsive polymer gel were classified to obtain particles of the pH-responsive polymer gel having a volume average particle size of 10 μm when dried.

The water absorption of the obtained pH-responsive polymer gel particles in a 0.0001 mol / l sodium hydroxide aqueous solution was 200 g / l. In addition, by changing the pH, swelling and shrinking can be reversibly performed. Between pH 3.0 (shrinking) and pH 10 (swelling), the volume average particle diameter is 4 times and the volume is 64 times. Had the property of causing

-Preparation of Optical Element- An oxidation-reduction electrode formed only in the polypyrrole layer prepared in the same manner as in Example 1 and a transparent electrode similar to that in Example 1 on which spacer particles of 50 μm are dispersed are superposed. ,
An ultraviolet curable resin was applied to the outer peripheral portion except for the opening, cured by irradiating ultraviolet rays, and sealed.

0.00 containing pH-responsive polymer gel particles
After injecting an aqueous solution of 01 mol / l sodium hydroxide by a reduced pressure encapsulation method in the same manner as in Example 1, the opening was sealed to produce an optical element.

Since the polypyrrole layer is colored black and absorbs most of the incident light, the amount of transmitted light was 0.1%.

-Evaluation of Optical Element- An optical element was evaluated in the same manner as in Example 1. From microscopic observation, it was confirmed that the pH-responsive polymer gel particles were contracted by the application of electricity. However, air bubbles were generated from the counter electrode (transparent electrode) on which the redox layer was not formed during energization, and no change in the amount of transmitted light was observed.

[0126]

The optical element of the present invention has a large variation in light scattering rate, reflectance, light absorption, etc., and has stable repetition characteristics. In addition, the structure is easy in manufacturing, and is useful as a color display element. Further, by using the optical element of the present invention, the color tone can be easily changed to a predetermined color tone.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating an example of an optical element of the present invention.

FIG. 2 is a schematic configuration diagram showing another example of the optical element of the present invention.

FIG. 3 is a schematic configuration diagram showing another example of the optical element of the present invention.

FIG. 4 is a schematic configuration diagram showing another example of the optical element of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Transparent electrode 2 ... Redox electrode 3 ... Electrode 4 ... Redox layer 5 ... Stimuli-responsive polymer gel 6 ... Liquid 7 ... Spacer

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroaki Tsutsui 1600 Takematsu, Minamiashigara-shi, Kanagawa Prefecture Inside Fuji Xerox Co., Ltd. ) Inventor Akashi Kazuro 1600 Takematsu, Minamiashigara-shi, Kanagawa Prefecture Fuji Xerox Co., Ltd.

Claims (11)

[Claims] 1. A stimulus-responsive polymer gel that swells or contracts by an external stimulus and has a redox ability, at least between a transparent electrode and a redox electrode having an oxidation-reduction ability; A liquid that can be absorbed by a molecular gel, wherein the stimulus-responsive polymer gel is arranged near the transparent electrode. 2. A stimulus-responsive polymer gel which swells or shrinks by an external stimulus and has a redox ability, at least between a transparent electrode and a redox electrode having an oxidation-reduction ability; An optical element comprising: a liquid that can be absorbed by a molecular gel; and wherein the stimulus-responsive polymer gel is in contact with the transparent electrode. 3. The optical element according to claim 1, wherein the stimulus-responsive polymer gel swells or contracts due to a redox reaction. 4. The optical element according to claim 1, wherein a light-shielding layer is formed on the surface of the redox electrode. 5. The stimulus-responsive polymer gel according to claim 1, wherein the stimulus-responsive polymer gel is obtained by crosslinking at least a polymer compound having a functional group having a redox ability. Optical element. 6. The interpenetrating network structure formed by at least a crosslinked polymer compound having a functional group having a redox ability and a crosslinked other polymer compound, wherein the stimuli-responsive polymer gel has at least Claim 1 characterized by having
5. The optical element according to any one of 4. 7. The optical element according to claim 5, wherein a charge state of the functional group is changed by an oxidation-reduction reaction of the functional group having a redox ability. 8. The ionic concentration of a liquid that can be absorbed by the stimulus-responsive polymer gel is changed by the redox reaction of the functional group having the redox ability. Optical element. 9. The optical element according to claim 1, wherein the stimulus-responsive polymer gel contains a light modulating material. 10. The stimulus-responsive polymer gel contains the light modulating material at a concentration of at least a saturation absorption concentration or a saturation scattering concentration at the time of contraction of the stimulus-responsive polymer gel. The optical element according to claim 9, wherein: 11. The stimulus-responsive polymer gel is energized to control the oxidation-reduction state of the stimulus-responsive polymer gel to reduce the swelling and shrinkage of the stimulus-responsive polymer gel. A modulation method characterized by controlling.