KR810000777B1 - Electrochromic devices with polymeric electrolytes - Google Patents

Abstract

No content.

Description

Electro optics

The present invention relates to an improved electro-optical device comprising a layer of persistent electrochromic material on one electrode, wherein one electrode of the device is in electrical contact with a special polymer electrolyte while the electrolyte It is in electrical contact. The device works when a current flows between the electrodes through the electrolyte described above. This apparatus includes a device in which an electric field can be applied to an electrode, and a device for changing the light absorption characteristics of the electroreversible discoloration layer by reversing the electric field by reversing the polarity of each electrode. Such devices having various uses have been conventionally disclosed in various types. For example, it relates to electroreversible discoloration apparatus using special gelled electrolyte solution, polyester, vinyl polymer, allyl polymer, polycarbonate, phenolic, amino resin, polyamide, polyimide and cellulose resin. It is not disclosed to use plastics such as the electroreversible discoloration apparatus, to use perfluorinated sulfonic acid as the electrolyte for the electroreversible discoloration apparatus, or to use the polymer in the apparatus.

The present invention is to improve the conventional electroreversible discoloration apparatus using a special polymerization electrolyte to make a longer duration device. As the electrolyte, a copolymer of a vinyl monomer and a monomer containing an acid group was used.

The "continuous electrochromic material" used in the present invention, when applied to an electric field of a given polarity, is absorbable to electromagnetic radiation in a first continuous state which is essentially nonabsorbable to electromagnetic radiation in a given wavelength region in response thereto. Phosphorus is a substance that changes into a secondary persistent state and, when applied to the electric field of opposite polarity in the secondary state, returns to the primary state in response. Some of these materials may return to their initial state even in the absence of a battlefield in response to a short circuit.

The term "persistence" refers to the property that a substance remains in the state of absorption reached after it has been removed, which is different from the instantaneous reduction to the initial state as in the case of the Franz-Keldish effect.

Generally, the material forming the electroreversible discoloration material used in the apparatus is an electrical insulator or a semiconductor. Excludes compounds containing metals, alloys and other metals that are relatively electrical conductors.

Persistent electroreversible discolorants are characterized as inorganic, i.e. they are either pure elements, mixtures or compounds, which are solid under the conditions of use and present in one or more oxidized states besides non-oxidized states, i.e. It contains at least one element of the periodic table. "Oxidation status" is defined in "Inorganic Chemistry", a book by T. Moeller, published by John Wiley & Sons Inc. in 1952.

These are materials containing transition metal elements (including lanthanide and actinium elements) and non-alkali metal elements such as copper, the most selective of which are in the range of +2 to +8 oxidation state. Thin films of transition metal compounds present in, for example, transition metal oxides, transition metal oxygen sulfides, transition metal halides, selenides, tellurides, chromates, molybdates, vanadium salts, niobates, tantalates, thi Carbonates and the like. Particularly optionally used are metal stannate, compounds of group 4B, 5B rust and 6B metals of the periodic table, and lanthanide metal oxides and sulfides. Examples include copper stannate, tungsten oxide, cerium oxide, cobalt tungsten oxide, and molybdenum. Acid metals, metal titanates, metal niobates, and the like.

Although there is no known mechanism for persistent electroreversible discoloration, it has been observed to be colored in the negatively charged electroreversible discoloration layer. In general, the phenomenon of persistent electroreversible discoloration transfers positive ions such as hydrogen or lithium ions to the cathode. Therefore, it is believed that a colored spot is formed in the electroreversible discoloration image layer due to the charge that cancels the electron flow.

When used as a thin film of persistent electro-reversible discoloration material, the preferred thickness range is about 0.1 to 100 microns. However, if there is even a little dislocation, it shows a considerably large electric field strength through the thin film, so a thickness range of 0.1 to 10 microns is better than a thick range.

The optimum thickness is determined by the properties of the specific compound formed by the thin film and the thin film forming method, because the specific compound or thin film forming method is physical (eg, uneven thin film surface) and economical limitations in the fabrication of the device.

When tungsten oxide is used as an electroreversible discoloration imaging material, electric field is applied between the electrodes, which previously was colorless, and the electroreversible discoloration layer was colored blue. In other words, the persistent electroreversible discoloration layer initially surrounded the red part of the visible spectrum. It is absorbed by the large electromagnetic radiation, which causes the image layer to develop in blue. Electroreversible discoloration imaging layers prior to application of the electric field are essentially nonabsorbable and therefore colorless.

The electrode used is any material made of a material that is electrically conductive compared to the electroreversible discoloration film. The electrically conductive material is generally coated on a suitable substrate such as glass, wood, paper, plastic, gypsum, etc., and is transparent, translucent and opaque. To other optical properties may also be used as the substrate. At least one of the electrode and the substrate forming material is transparent and both the electrode and the substrate may be transparent.

Copolymers that can be suitably used in the present invention should be essentially hydrophilic vinyl-based resins, but these resins are ionically conductive because they are combined with a compatible monomer containing an acid group. The copolymer thus prepared is characterized as being hydrophilic and inevitably transparent, having mechanical toughness and stability, proton conductivity and electronic insulation. The copolymer may be optionally crosslinked and may contain a moisturizer to improve the hydrophilicity of the copolymer.

Preferably, the copolymer may be prepared insoluble in water or insoluble in water by a crosslinking method.

Preferred vinyl monomers can be used as hydroxy lower alkyl (C _1-4 ) acrylates or methacrylates or hydroxy lower alkoxy (C _1-4 ) acrylates or methacrylates, for example 2-hydroxyethyl. Acrylate, 2-hydroxyethyl methacrylate, diethylene glycol monomethacrylate, 2-hydroxypropyl acrylate, 2-hydroxy-propyl methacrylate, 3-hydroxypropyl acrylate, 3-hydroxy -Propyl methacrylate, dipropylene glycol monomethacrylate, dipropylene glycol monoacrylate, 2,3-dihydroxypropyl methacrylate, and the like. The most commonly used monomers are hydroxyalkyl acrylates and methacrylates, in particular 2-hydroxyethyl methacrylate.

Also it is used as other than the monomers there is acrylamide, meth acrylamide, N- alkyl (C _1-6) substituted acrylamides and methacrylate amides, amido-substituted alkyl, N- (C _1-6) acrylate and Drew Those belonging to the methacrylamides include N-propyl acrylamide, N-isopropyl acrylamide, N-isopropyl acrylamide, N-propyl methacrylamide, N-butyl acrylamide, N-methyl acrylamide and N- Methylmethacrylamide, diacetoneacrylamide, N- (2-hydroxyethyl) acrylamide, N- (2-hydroxyethyl) methacrylamide, N-vinyl-2-pyrrolidone and N-isobutoxymethyl) Acrylamide and the like.

Other suitable copolymerizable monomers include methyl acrylate, ethyl acrylate, isopropyl acrylate, propyl acrylate, butyl acrylate, sec-butyl acrylate, pentyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate Ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, butyl methacrylate, sec-butyl methacrylate, pentyl methacrylate, aryl acrylates such as benzyl or phenyl acrylate or methacryl Rates, lower alkoxyethyl acrylates and methacrylates such as methoxyethyl acrylate, methoxyethyl methacrylate ethoxyethyl acrylate, ethoxyethyl methacrylate, triethylene glycol monoacrylate, triethylene Glycol Monoethylacrylate, Glycerol And the like furnace acrylate and glycerol mono methacrylate.

Unsaturated amines are also used, such as P-aminostyrene, O-aminostyrene, 2-amino-4-vinyltoluene, alkylaminoalkyl acrylates and methacrylates, and these alkylaminoalkyl acrylates and methacrylates. Diethylaminoethyl acrylate, diethylaminoethyl methacrylate, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, N, N-dimethylaminopropyl methacrylamide, methacryl aminopropyl trimethylammonium halide, t-butylaminoethyl acrylate, t-butylaminoethyl methacrylate, piperidinoethyl acrylate, piperidinoethyl methacrylate, morpholinoethyl acrylate, morpholinoethyl methacrylate, 2-vinyl Pyridine, 3-vinylpyridyl, 4-vinylpyridine, 2-ethyl 5-vinylpyridine, dimethyl Minopropyl acrylate, dimethylaminopropyl methacrylate, dipropylaminoethyl acrylate, dipropylaminoethyl methacrylate, di-n-butylaminoethyl acrylate, di-n-butylaminoethyl methacrylate, di- sec-butylaminoethyl acrylate, di-sec-butylaminoethyl methacrylate, dimethyl aminoethyl vinyl ether, diethylaminoethyl vinyl ether, diethylaminoethyl vinyl sulfide, aminoethyl vinyl ether, aminoethyl vinyl sulfide, mono Methylaminoethyl vinyl sulfide, monomethylamiethyl vinyl ether, N- (gamma-monomethylamino) propyl acrylamide, N- (beta-monomethylamino) ethyl acrylamide, N- (beta-monomethylamino) ethyl meta Acrylamide, 10-aminodecyl vinyl ether, 8-aminotinyl vinyl ether, 5-aminopentyl vinyl ether, 3-aminopropyl vinyl ether , 4-aminobutyl vinyl ether, 2-aminobutyl vinyl ether, monoethylaminoethyl methacrylate, N- (3,5,5-trimethylhexyl) aminoethyl vinyl ether, N-cyclohexylaminoethyl vinyl ether, 2 -(1,1,3,3-tetramethyl butylamino) ethyl methacrylate, Nt-butylaminoethyl vinyl ether, N-methylaminoethyl vinyl ether, N-2-ethylhexylaminoethyl vinyl ether, Nt-butyl Aminoethyl vinyl ether, Nt-octylaminoethyl vinyl ether, 2-pyrrolidinoethyl acrylate, 2-pyrrolidinoethyl methacrylate, 3- (dimethylaminoethyl) 2-hydroxypropyl acrylate, 3- ( Dimethylaminoethyl) -2-hydroxypropyl methacrylate, 2-aminoethyl acrylate, 2-aminoethyl methacrylate, and the like.

Acid group-containing monomers used in the present invention are those which are copolymerized with the above-described vinyl monomers so as to contain acid functional groups, particularly strong acid functional groups such as sulfonic acid or phosphoric acid. Suitable acidic comonomers belonging thereto are 2-acrylicamino-2-methylpropane sulfonic acid, 2-sulfoethyl methacrylate, alpha-cyanoacrylic acid, methacrylic acid acrylic acid, alpha-fluorinated acrylic acid, itaconic acid, Fumaric acid, maleic acid, alpha-brominated acrylic acid, cinnamic acid, alpha-nitroacrylic acid, vinyl acetic acid alpha-vinyl chloride acetic acid, alpha-vinyl fluoride acetic acid, alpha-vinyl bromide acetic acid, 2-vinylpropionic acid, aconitic acid, allyl acetic acid, 2-allyloxypropionic acid, 2-allylphenoxyacetic acid, crotonic acid, allylasonic acid, vinylphosphonic acid, allylphosphonic acid, alpha-propenylphosphonic acid, alpha-styrylphosphonic acid, 2-chloro-3-butyl- 1-phosphonic acid, 2-chloro-1,3-butadienylphosphonic acid, allylphosphonic acid, acrylamidomethylphosphonic acid, 4-vinylsalicylic acid, 2,2-difluoro-3-butenoic acid, and these Derivatives of

Acid-containing monomers have a serviceability of at least 5% by weight, usually at least 10%, but at most 20% up to 80% when used most.

The copolymer may optionally increase at least partially crosslinking to increase the dimensional stability and insolubility of the resulting polymer. Suitable crosslinkers include ethylene glycol diacrylate, ethylene glycol dimethacrylate, 1,2-butylene dimethacrylate, 1,3-butylene dimethacrylate, 1,4-butylene dimethacrylate, propylene Glycol diacrylate, propylene glycol methacrylate, diethylene glycol dimethacrylate, dipropylene glycol dimethacrylate, diethylene glycol diacrylate, dipropylene glycol diacrylate, divinylbenzene, divinyltoluene, di Allyl tartrate, divinyl tartrate, triallyl melamine, N, N'-methylenebis-acrylamide, glycerin trimethacrylate, diallyl millate, divinyl ether, diallyl mono ethylene glycol citrate, ethylene glycol vinyl Allyl citrate, allyl vinyl maleate, diallyl itaconate, ethylene glycol diester of ataconic acid, Vinyl sulfone, hexahydro 1,3,5-triacryloyltriazine, triallyl phosphite, diallyl ester of benzenephosphonic acid, polyester of maleic anhydride and triethylene glycol, polyallyl glucose, for example triallyl Glucose, polyallyl sucrose for example pentaallyl sucrose, sucrose diacrylate, glucose dimethacrylate, pentaerythritol tetraacrylate, sorbitol dimethacrylate, diallyl aconitate, divinylcitraconate , Diallyl fumarate, allyl methacrylate, polyethylene glycol diacrylate, and the like.

The crosslinking agent described above becomes a free radical by heating the polymer in the presence of an ionizing catalyst or during the polymerization reaction. The crosslinking reaction can also be carried out by condensation reaction with nuxamethylolmelamine, hexamethoxymethylmelamine, dimethylolurea, dimethylolhydantoin, formaldehyde, glyoxal and the like.

Other crosslinking agents capable of binding comonomers include glycidal methacrylate, N-methylol acrylamide and isobutoxymethylacrylamide.

When the copolymer is coated by bonding in an electroreversible discoloration apparatus, the polymerization coating may be crosslinked by electron beam, ultraviolet radiation, ionization radiation, or heat treatment.

In order to improve ionic conductivity over a long period of time, it is preferable to add a small amount of a moisturizer of up to about 25%. Suitable moisturizers include glycerol tetraethylene glycol and polyalkylene oxides having other hydroxyl groups as end groups.

Organic solvents which can be prepared in a casting syrup, an aqueous dispersion or a solution in an organic solvent by an aqueous suspension polymerization method include ethyl alcohol, methyl alcohol, propyl alcohol, isopropyl alcohol, formamide, Use dimethyl sulfoxide or other suitable solvent.

The polymerization reaction is carried out at about 20 ° to 150 °, which is often performed in the temperature range of 35 ° or 40 ° to 90 ° C. When the coating is completed, the polymerization is finished. The range of 0.95 to 1 percent of the polymerizable monomer can be polymerized using a free group initiator. Typical initiators include azobisisobutyronitrile, ammonium persulfate, t-butylperoctonate, benzoyl peroxide, isopropyl percarbonate, 2,4-dichlorobenzoyl peroxide, methyl ethyl ketone peroxide, cumin peroxide, and dicumyl peroxide Etc. Irradiation, such as ultraviolet or gamma rays, also initiates polymerization.

The polymer electrolyte is dissolved in a suitable solvent, adhered to the lower layer in the apparatus, and the solvent is evaporated to form a polymer electrolyte formed of a solid membrane. In this way, the polymer electrolyte can be bonded to the electroreversible discoloration apparatus. The electrolyte is usually from about 10,000 kPa to 100,000 kPa or more and the appropriate thickness depends on the type of polymer, the number and type of protective layers, and the application in which the device is used.

One or more supplementary layers in close contact with the polymerized electrolyte were formed to further improve the reverse discoloration apparatus, which is thought to be the electronic insulation between transmission and conduction between the electron conductive layers adjacent to the apparatus and from these layers. The materials suitably used as the insulating layers may be the same or different, but are preferably the same, and silicon oxide, calcium fluoride and magnesium fluoride are used, and other metal oxides or metal sulfides are used. Is oxidized or sulfided so that an insulator is formed directly. Examples of such materials include aluminum oxide and other inorganic insulators, for example, selenides, bisulfides, nitrides, chlorides, fluorides, bromide and carbides in addition to the above materials.

The insulation layer should be thick enough to provide sufficient electronic insulation for the required time, but not so thick as to damage ion transmission or ion conduction.

Generally, a thickness of about 100 to 1500Å is used. The thickness varies depending on the insulation used. In the case of silicon oxide, the preferred thickness is about 350-450 mm 3 and the magnesium fluoride is about 200-300 mm 3. As the thickness becomes thicker beyond this requirement, the switching speed is reduced with a constant drive voltage.

If only one insulation protective layer is used, it should be installed between the polymer electrolyte and the electroreversible discoloration device to prevent unwanted reaction between the polymer and the thin film.

In the case of using the reverse electrode made of gold in the device of the present invention having the insulating layers on both sides of the polymer electrolyte, a thinner nucleation film is provided between the insulating layer and the gold electrode to give a better result. It is a device to be improved.

Suitable materials for the nucleation layer include palladium, platinum, and rhodium, and palladium is used more in consideration of double proton conductivity.

The device of the present invention is convenient to install since one layer can be laminated on the other layer to form the required structure.

Some specific examples which follow are intended to further illustrate the present invention and present specific details and methods thereof, but are not limited to the present examples.

Example 1

10 g of 2-hydroxyethyl methacrylate, 2-glyamide 2-methylpropanesulfonic acid, 1 g of methyl methacrylate, 50 g of ethanol, 30 g of methanol, 0.1 g of azobisisobutyronitrile, 2 g of water, agitator, heating oil The flask with an oil bath and nitrogen gas outlet is charged via a reflux condenser. The mixture was sparged with nitrogen in a flask and heated to 65 ° C. for 10 minutes and then stirred at 65 ° C. for 12 hours in a nitrogen atmosphere. The copolymer solution prepared by diluting the reactant with 30 g of ethanol and 10 g of water and then cooling to 25 ° C. is ready to use an electroreversible discoloration apparatus.

Example 2

12 g of 2-hydroxyethyl methacrylate, 2 g of 2-acrylamido-2-methylpropanesulfonic acid, 0.05 g of ethylene glycol dimethacrylate, 50 g of ethanol, 30 g of methanol, 0.1 g of azobisisobutyronitrile, and 4 g of water Charge the flask with a stirrer, a heated oil bath and a nitrogen extractor through a reflux condenser.

The mixture was sputtered with nitrogen in a flask and heated to 65 ° C. for 10 minutes and then stirred at 65 ° C. for 12 hours in a nitrogen atmosphere. After the reaction was cooled to 25 ° C., 80 g of ethanol and 20 g of water were diluted to prepare the copolymer solution.

[Example 3]

9g of 2-hydroxyethyl methacrylate, 2-glyaclamido-2-methylpropanesulfonic acid, 50g of ethanol, 30g of methanol, 0.07g of azobisisobutyronitrile and a flask with stirrer, heated oil bath and nitrogen soak outlet Charge via reflux condenser.

The mixture was sputtered with nitrogen in a flask and heated to 65 ° C. for 10 minutes and then stirred at 65 ° C. for 12 hours in a nitrogen atmosphere. The copolymer solution prepared by cooling the reaction to 25 ° C. and diluting with 40 g of ethanol was prepared for use in an electroreversible discoloration apparatus.

Example 4

An electroreversible discoloration pane with an area of 14 cm ² is prepared in the following manner.

A copolymer of methacrylic acid (MA) of hydroxyethyl methacrylate (HEM) is prepared in a ratio of 2 parts HEM to 1 part MA, and then dissolved in ethanol to make a 5% solution. A tungsten oxide layer having a thickness of about 5000 mm 3 is attached to the transparent conductive indium oxide layer deposited on the glass. Using a spinner model EC101, a 5% copolymer solution was attached to the tungsten oxide layer by spin coating to dry it, and the dried copolymer layer was about 10-30 microns thick. Next, a transparent gold layer having a thickness of about 125 mm 3 is attached on the polymer layer.

The device was tested through a direct current potential of about 2.0 volts between the indium oxide and the gold layer with the indium oxide thin layer as negative, and the photoconductivity was reduced in a few seconds. As the polarity reversed, the color became transparent, increasing the photoconductivity.

Example 5

An electroreversible mirror with an area of 14 cm 2 was prepared by the following method.

A terpolymer consisting of 1 part of 2-acrylamido-2-methylpropanesulfonic acid (AMPS), 2 parts of hydroxyethyl methacrylate (HEM), and 1 part of methyl methacrylate (MMA) was prepared and dissolved in ethanol. Made in% solution. On the other hand, a tungsten oxide layer is deposited on the glass substrate, and then a reflective palladium layer is deposited thereon, followed by a silicon oxide layer. The AMPS-HEM-MMA polymer was attached to the thin film thus formed in the same manner as in Example 1 to form an embankment electrode.

Tests of the diameter of the palladium layer with a gold layer made of two volts between the palladium layer and the gold layer showed that when the palladium layer was negative, the mirror from the glass side disappeared and the reflectance was reflected when the palladium layer was positive.

Example 6

The electroreversible discoloration information indicator is manufactured as follows.

After preparing the HEM-AMPS copolymer in a ratio of 11: 3 by weight, the polymer was dissolved using a solution of 4 parts of ethanol and 1 part of water to obtain a final concentration of 11%. Next, a white titanium oxide pigment is added to the polymer solution in a ratio of 5 parts of pigment to 1 part of polymer solids and mixed. Tungsten oxide was vacuum-deposited through a mask on a transparent conductive tin oxide ion substrate to form a soda 8 consisting of 5 mm in height and 7 pieces. A white polymer paste was applied onto the glass electrode and a carbon paper electrode was pressed into the paste.壓 入) to complete the assembly. When dried, the paste hardens so that the electrical terminals are bound to the tin oxide layer and the carbon paper electrode. The indicator thus produced was operated for more than 500 cycles.

Example 7

The same weighted monomers are used in the same manner as in Example 6 to obtain the corresponding crosslinked copolymer.

Hydroxyethyl methacrylate 100

2-Acrylamide-2-methylpropanesulfonic acid 50

Nuxamethylolmelamine 1

Coupling the copolymer to the electroreversible discoloration device resulted in operation for more than 700 cycles.

Claims (1)

One electrode, a layer of persistent electro-reversible discoloration material in contact with the electrode, an ion-conducting and hydrophilic vinyl polymer electrolyte in contact with the layer, and an electrical device for selectively applying a reverse polarity electric field between the reverse electrode and the electrodes to the electrolyte. Wherein the electrolyte comprises 95 to 20 weight percent vinyl monomer and 5 to 80 weight percent acid group selected from 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxyethyl acrylate An electro-optical device composed of a copolymer of a monoethylenically unsaturated monomer containing or a partially crosslinked copolymer.