JP2001202037A - Image display medium and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image display medium which makes image display by holding microcapsules for display including coloring balls having surfaces composed of >=2 kinds of regions varying in optical characteristics and electrostatic charge characteristics and an insulative liquid on a base and rotating the coloring balls by controlling the electric fields to be applied to the coloring balls and has flexible paper-like characteristics. SOLUTION: The microcapsules formed by coating the coloring balls and the insulative liquid with shells consisting of the resins obtained by an interfacial polymerization method are used. The particle size of the microcapsules is suitably 1.0 to 2.0 times the particle size of the coloring balls.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microcapsule for display having different optical characteristics and charging characteristics.
The present invention relates to a display medium that performs display by rotating a colored ball having a surface composed of at least three types of regions, and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, with the development of information equipment, needs for low power consumption and thin display devices have increased, and research and development of display devices meeting these needs have been actively conducted. Among them, the liquid crystal display device is capable of electrically controlling the arrangement of liquid crystal molecules to change the optical characteristics of the liquid crystal, and has been actively developed and commercialized as a display device capable of meeting the above needs. However, these liquid crystal display devices have not yet sufficiently solved the difficulty in seeing characters on the screen due to the angle at which the screen is viewed or the reflected light, and the visual burden caused by flickering and low brightness of the light source. For this reason, research on a new display device with a small burden on vision is being actively studied.

A new display device is disclosed in US Pat.
No. 3,103, and No. 4,126,854, a particle rotating type for displaying an image using display particles having a configuration in which each hemisphere of a spherical material is color-coded. Displays are known. Microencapsulation of display particles is disclosed in JP-A-8-234686.

This display device uses minute colored balls, one of the colored balls being white and the other hemispherical being black, and the colored balls are arranged in a gap formed in a support. Each space is filled with a high-resistance liquid so that the ball can freely rotate in the liquid. In this case, the black and white hemispherical portions of the ball have different charging states, and by applying an external electric field, the rotation can be controlled so as to face the side where the white or black hemispherical surface of the ball is observed, The intended display can be made. As a manufacturing method, a minute colored ball and silicone rubber are mixed and solidified, and then immersed in silicone oil to swell the silicone rubber to form a space filled with oil around the ball. Next, it is manufactured by being sandwiched between two glass substrates on which electrode patterns are formed. Such a mechanical display method is extremely stable against temperature changes and electrical noise, and does not require power during display because of its memory properties. Furthermore, since the display is performed by using the reflection and scattering of natural light on the ball surface, there is an advantage that eye fatigue caused by flickering of a light source as seen in a liquid crystal device or a cathode ray tube can be suppressed.

On the other hand, portable information devices have recently been developed and spread at a very high speed. In these devices, not only the conventional low power consumption and thin type, but also a lighter and more flexible display device that can be installed to some extent in accordance with the shape of the device is required, and its development is urgently required.

[0006]

However, it has been difficult to produce a display device that satisfies all of the requirements by the conventional method. That is, the colored ball rotating display device has excellent characteristics in terms of low power consumption, thinness, and low eye fatigue, but it has been difficult to be flexible due to the following problems.

In the colored ball rotating type display device, since the silicone rubber is swelled by being immersed in a silicone oil liquid to form a space around the colored ball, two silicone rubbers swollen by the oil are removed. Due to the structure sandwiched between the substrates, the oil causes very poor adhesion between the glass substrate and the silicone rubber. Therefore, when a flexible structure is used by using a polymer film or the like for the substrate, the silicone rubber moves between the flexible substrates due to low adhesion and softness,
A problem arises because the colored balls are unbalanced. Therefore, it was difficult to manufacture a flexible colored ball rotating display device. In order to avoid such difficulties, coating a colored ball with microcapsules is disclosed in
No. 234,686 discloses a capsule manufacturing method called an orifice method in which a mixture of a colored ball and a dielectric liquid is put into a film-forming liquid to form a capsule film. Fine control of the capsule film thickness is not possible, which adversely affects the visibility of the colored ball.

[0008]

In order to solve the above-mentioned problems, the present invention employs the following image display medium and its manufacturing method.

A colored ball having a surface constituted by two or more regions having different optical characteristics and charging characteristics and a display microcapsule containing an insulating liquid are held on a support, and an electric field applied to the colored ball An image display medium for displaying an image by rotating a colored ball by controlling the display ball, wherein the colored ball and the insulating liquid are covered with a resin shell formed by using an interfacial polymerization method. An image display medium characterized by forming a capsule.

A dispersion obtained by dispersing the colored balls in a mixture of the insulating liquid and a first reactive component for forming a resin shell is mixed with the first reactive component by an interfacial polymerization method. By adding to the aqueous solution containing the second reactive component forming a resin coating by the above, to produce a microcapsule for display covering the insulating liquid and the colored ball, the image display medium of Production method.

[0011] The first reactive component is selected from polyhydric isocyanate and / or polybasic acid chloride, and the second reactive component is selected from polyhydric amine and / or polyhydric alcohol. A method for manufacturing an image display medium.

2. The image display medium according to claim 1, wherein the particle diameter of the display microcapsules is 1.0 to 2.0 times the particle diameter of the colored balls.

A display medium is manufactured by sandwiching the display microcapsules together with an adhesive or the like between, for example, two substrates on which electrode patterns are formed. In the present invention, at least one of the two substrates only needs to be light-transmitting. This is because the observer can check the display if light can pass through only the display side film where the observer is located.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The display device of the present invention rotates a colored ball in a display microcapsule at a desired position by applying a voltage to striped electrodes orthogonal to each other formed on upper and lower substrates. Then, white or black display is performed. An image can be displayed by sequentially performing this scanning in the plane.

The colored balls used are made of synthetic resin having good insulating properties, such as polystyrene, polymethyl methacrylate, and polyethylene. In addition, a white material such as titanium oxide, zinc oxide or aluminum oxide may be used in combination with magnesium fluoride and aluminum. Each of the hemispheres has a chargeability and display color, such as a hemisphere coated with a colored material such as a vapor deposition layer or a titanium carbide layer, or vice versa, or a material obtained by laminating a colored material and a white material on a hemisphere portion of a transparent material ball such as glass. However, different balls can be used.

The smaller the particle size of the colored ball, the higher the resolution of image display. However, if the particle size is too small, it is difficult to manufacture the ball and the density of the display color becomes insufficient.
Micron-sized ones are preferably used.

By coating a colored layer on the surface of the colored ball, two surfaces having different optical characteristics such as the color of reflected light and the reflection intensity are created. The coloring layer is preferably a material that is stable in an insulating liquid, has high mechanical strength, and has good adhesion to the ball surface. Further, the color of the colored layer is not limited to white and black,
Yellow, magenta, cyan and the like may be used.

An example of the image display medium of the present invention will be described.
A minute colored ball with a colored layer and a display microcapsule containing an insulating liquid are provided between two substrates on which an electrode pattern is formed together with an adhesive, and the colored ball can be freely placed in the display microcapsule. And a driving means comprising a power supply and an electrode sandwiched on both sides for rotating the colored ball to display a desired colored layer side. This is based on the premise that the present invention is used as a paper-like display.
When using as `` paper '', that is, as a rewritable sheet, it is not necessary to form a special electrode pattern in advance because existing electrostatic latent image forming methods such as laser printer and ion deposition printer can be applied. .

An example of the driving principle of the display device of the present invention will be described. It is known that, in a colored ball in an insulating liquid, electric charges are transferred between the colored ball and the insulating liquid to form an electric double layer, and the particles are positively or negatively charged.
In the colored ball of the present invention, a black colored layer is formed on the surface of the hemisphere, and the other hemisphere is white, so that it has regions composed of two different substances. Therefore, positive ion particles or negative ion particles are specifically adsorbed on the surface of the colored ball from the insulating liquid, and a surface potential is generated on the surface of the colored ball. For this reason, in the insulating liquid, the charging characteristics are different in each region, and the colored ball has a dipole moment in the pole direction. When an electric field is applied to the colored ball, a torque acts on the colored ball to align the pole direction with the electric field direction,
The colored ball aligns any hemisphere in one direction. Assuming that the white microball area is negatively charged and the black layer is positively charged, the white microball side comes to the electrode to which plus is applied by the power source, and the colored layer side to the electrode to which minus is applied. Thus, when the display device of the present invention is observed from above, a white color is seen. If the direction of the electric field is reversed, the minute balls are reversed, and the black layer side is turned to the observation side, and black is seen.

As the liquid used for the insulating liquid, any liquid having a high electrical insulating property may be used, and an organic solvent such as toluene or acetone or water may be used. It is preferable to use a non-volatile liquid so as not to cause such a problem. Particularly, a transparent silicone oil is a liquid having a low content of ions and impurities and a high resistance, and is therefore preferable. Also, the insulating liquid comes into contact with the colored ball,
It has the property of surface-activating the surface of the colored ball to induce two different charged states.

The size of the gap filled with the insulating liquid is preferably slightly larger than the colored ball in order to prevent translation of the colored ball as much as possible and to have a memory property. That is, the average particle size of the display microcapsules is preferably greater than 1.0 times and up to about 2.0 times the average particle size of the colored balls. When the particle size of the microcapsules becomes larger, the difference in the refractive index adversely affects the transparency of the capsule wall due to the insulating liquid interposed between the colored ball and the resin outer shell, impairing the visibility of the colored ball. I do.

Conventionally, microcapsules have been produced by coacervation, in situ polymerization,
An interfacial polymerization method and an orifice method are known. The coacervation method is an encapsulation method that utilizes the phase separation phenomenon of water-soluble polymers such as gelatin, gum arabic, and carboxymethyl cellulose.This method requires a long manufacturing time, complicated processes, and low-concentration capsule dispersion. Since only a liquid can be obtained, and natural polymer materials are used, there are problems such as poor quality stability, spoilage and water resistance. On the other hand, the interfacial polymerization method is a method using a polyurea / polyurethane film obtained by reacting a polyvalent isocyanate with water, a polyamine or a polyhydric alcohol,
It has advantages such as a simple manufacturing process and a high-concentration capsule, and has attracted attention in recent years. Here, the polyurea / polyurethane membrane is a polyvalent isocyanate,
Water, a polyurea chemical structure generated from polyvalent amines and a polyurethane chemical structure generated from polyvalent isocyanate and polyhydric alcohol are used as an encapsulation film.Other reactions between epoxides, hydroxyl groups, amino groups, carboxyl groups, and amino groups A composite compound structure film formed by a reaction with a carboxyl group or a reaction between a (meth) acryloyl group and an amino group. A conventionally known microcapsule formed by the interfacial polymerization method has a relatively thin capsule wall film, and is suitable for the purpose of the present invention.

Next, a method for producing the display microcapsule of the present invention will be described in detail. In order to produce the microcapsules of the present invention, first, an insulating liquid and a first reactive component having compatibility with the insulating liquid, for example,
The colored balls dispersed in a polyvalent isocyanate, a polybasic acid chloride or the like are dispersed by adding an appropriate organic solvent, if necessary, to form an oily substance.

The obtained oily substance (oil phase) is added to an aqueous medium (aqueous phase) containing a second reactive component, for example, a polyol and / or polyamine, and emulsified and dispersed using mechanical force. To form an oil-in-water emulsion in which the oily phase is emulsified and dispersed in the aqueous phase. In this case, the aqueous phase for emulsifying the core substance may contain a protective colloid in advance. As the protective colloid, a water-soluble polymer can be used, and known anionic polymers, cationic polymers,
Although it can be appropriately selected from amphoteric polymers, polyvinyl alcohol, gelatin, cellulose derivatives and the like are particularly preferable. The aqueous phase may contain a surfactant. As the surfactant, an anionic or nonionic surfactant which does not cause precipitation or aggregation by acting on the protective colloid can be appropriately selected and used. Preferred surfactants include sodium alkylbenzene sulfonate (eg, sodium lauryl sulfate), dioctyl sulfosuccinate sodium salt, polyalkylene glycol (eg, polyoxyethylene nonyl phenyl ether), and the like.

As described above, in an emulsion obtained by dispersing an oily substance in an aqueous dispersion medium, an interfacial polymerization reaction easily occurs on the surface of oily droplets by increasing the temperature, and a resin outer shell is formed. You. The polyamine and the polyol compound as the second reaction components in the aqueous phase may be previously present in the aqueous phase, or may be added during the formation of the resin shell.

Examples of the dispersant used in the present invention include natural polysaccharides such as gelatin, gum arabic and sodium alginate; semi-synthetic polysaccharides such as sodium carboxymethylcellulose and lignin sulfonate;
Synthetic water-soluble polymers such as polyvinyl alcohol and polyvinyl pyrrolidone, minerals such as magnesium aluminum silicate, alkylbenzene sulfonates, alkyl phosphates, formalin condensates of naphthalene sulfonates, higher alkyl sulfonates, higher alkyl quaternary Surfactants such as quaternary ammonium salts, higher fatty acids or salts thereof, and higher alkyl carboxylate salts can be used. Among these dispersants, gum arabic or polyvinyl alcohol is preferably used. For example, Gohsenol GL-05 (polyvinyl alcohol manufactured by Nippon Synthetic Chemical Industry, polymerization degree 1000 or less, saponification degree 86.5 to 89 mol%), gohsenol KL-05 (Polyvinyl alcohol manufactured by Nippon Synthetic Chemical Industry, polymerization degree 1000 or less, saponification degree 7
(8.5 to 81.5 mol%). These dispersants may be used alone, or two or more kinds may be mixed at an arbitrary ratio. Further, the amount of the dispersant added in the composition of the present invention may vary depending on the type of dispersant and the type and content of the pesticidal active ingredient, but is usually 0.5 to 20 relative to the total weight of the composition of the present invention. % By weight, preferably 2 to 10% by weight.

When a polyvalent isocyanate is used as a first reactive component for forming a resin coating by an interfacial polymerization reaction, for example, m-phenylenediisocyanate, p-
-Phenylene diisocyanate, 2,6-tolylene diisocyanate, 2,4-tolylene diisocyanate, naphthalene-1,4-diisocyanate, diphenylmethane-4,4'-diisocyanate, 3,3'-dimethoxy-4,4'-biphenyl -Diisocyanate, 3,
3'-dimethylphenylmethane-4,4'-diisocyanate, xylylene-1,4-diisocyanate,
4'-diphenylpropane diisocyanate, trimethylene diisocyanate, hexamethylene diisocyanate, propylene-1,2-diisocyanate, butylene-1,2-diisocyanate, cyclohexylene-1,
Diisocyanates such as 2-diisocyanate and cyclohexylene-1,4-diisocyanate, 4,4 ', 4 "
-Toluphenylmethane triisocyanate, toluene-
Triisocyanates such as 2,4,6-triisocyanate, 4,4'-dimethyldiphenylmethane-2,
Tetraisocyanates such as 2 ', 5,5'-tetraisocyanate, adducts of hexamethylene diisocyanate and trimethylolpropane, adducts of 2,4-tolylenediisocyanate and trimethylolpropane, adducts of xylene diisocyanate and trimethylolpropane And isocyanate prepolymers such as adducts of tolylene diisocyanate and hexanetriol.

When polybasic acid chloride is used as the first reactive component for forming a resin coating by an interfacial polymerization reaction, for example, malonyl dichloride, succinic chloride, glutar dichloride, adipoyl chloride, sebacoyl chloride, Examples include fumaric chloride, fumaryl chloride, itaconyl chloride, terephthalic acid chloride, phthaloyl chloride, isophthaloyl chloride, 1,3-naphthoic acid chloride, and 4,4′-biphenyl-dicarboxylic acid chloride.

As a material for forming the resin outer shell,
Silyl isocyanate can be used in combination. Specific examples of the silyl isocyanate include methylsilyl triisocyanate, dimethylsilyl diisocyanate, trimethylsilyl isocyanate, phenylsilyl triisocyanate, and silyl tetraisocyanate. In addition, a polymer material such as polyester, polycarbonate, epoxy resin, and urea-formaldehyde resin may be used in combination as a component of the resin outer shell.

When a polyol is used as the second reactive component for forming a resin coating by an interfacial polymerization reaction, examples thereof include aliphatic and aromatic polyhydric alcohols, hydroxypolyesters and hydroxypolyalkylene ethers. Further, the following polyols described in JP-A-60-49991 can also be used. Ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, propylene glycol, 3-dihydroxybutane, 1,2-dihydroxybutane, 1,3-dihydroxybutane, 2,2-dimethyl-1,3-propanediol, 2,4-pentanediol, 2,5-hexanediol, 3-methyl- 1,5-pentanediol, 1,4-cyclohexanedimethanol, dihydroxycyclohexane, diethylene glycol, 1,2,6
-Trihydroxyhexane, 2-phenylpropylene glycol, 1,1,1-trimethylolpropane, hexanetriol, pentaerythritol, pentaerythritol ethylene oxide adduct, glycerin ethylene oxide adduct, glycerin, 1,4-di (2- Hydroxyethoxy) benzene, condensation products of aromatic polyhydric alcohols such as resorcinol dihydroxyethyl ether and alkylene oxide, p-xylylene glycol, m-xylylene glycol, α, α'-dihydroxy-p-diisopropylbenzene, 4,4'-dihydroxy-diphenylmethane, 2- (p, p'-dihydroxydiphenylmethyl) benzyl alcohol, ethylene oxide adduct of bisphenol A, propylene oxide of bisphenol A Side additions. The polyol is preferably used in a ratio of 0.02 to 2 mol of the hydroxyl group to 1 mol of the isocyanate group.

As the polyamine, ethylenediamine,
Trimethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, p-phenylenediamine, m-phenylenediamine, piperazine, 2-methylpiperazine, 2,5-dimethylpiperazine, 2-hydroxytrimethylenediamine, diethylenetriamine, triethylenetriamine Examples include ethylenetetramine, diethylaminopropylamine, tetraethylenepentamine, and amine adducts of epoxy compounds.

The surfactant used in the composition of the present invention includes, for example, polyoxyethylene alkyl ether, polyoxyethylene alkyl allyl ether, polyoxyethylene lanolin alcohol, polyoxyethylene alkylphenol formalin condensate, polyoxyethylene sorbitan fatty acid ester , Polyoxyethylene glyceryl monofatty acid ester, polyoxypropylene glycol monofatty acid ester, polyoxyethylene sorbitol fatty acid ester, polyoxyethylene castor oil derivative, polyoxyethylene fatty acid ester, higher fatty acid glycerin ester, sorbitan fatty acid ester,
Nonionic surfactants such as sucrose fatty acid ester, polyoxyethylene polyoxypropylene block polymer, polyoxyethylene fatty acid amide, alkylolamide, and polyoxyethylene alkylamine; alkylamine hydrochloride such as dodecylamine hydrochloride; Quaternary ammonium salts such as quaternary ammonium salts and dodecylalkyltrimethylammonium salts, alkyldimethylbenzylammonium salts, alkylpyridinium salts, alkylisoquinolinium salts, dialkylmorpholinium salts, benzethonium chloride, polyalkylvinylpyridinium salts, etc. Cationic surfactants, sodium fatty acids such as sodium palmitate, and ether carboxylic acids such as sodium polyoxyethylene lauryl ether carboxylate Amino acid condensates of higher fatty acids such as thorium, sodium lauroyl sarcosine, sodium N-lauroyl glutamate, higher alkyl sulfonates such as sodium dodecylbenzene sulfonate, higher fatty acid ester sulfonates such as lauric ester sulfonate, dioctyl sulfo Dialkyl sulfosuccinic acid such as succinate, higher fatty acid amide sulfonic acid such as oleic amide sulfonic acid salt, dodecyl benzene sulfonate, alkyl allyl sulfonate such as diisopropyl naphthalene sulfonate, formalin condensate of alkyl allyl sulfonate Alcohol sulfates such as pentadecane-2-sulfate and polyoxyethylene alkyl ether sulfates such as sodium polyoxyethylene dodecyl ether sulfate. Salts, polyoxyethylene alkyl phosphates such as dipolyoxyethylene dodecyl ether phosphate, styrene-maleic acid copolymer, anionic surfactants such as alkyl vinyl ether-maleic acid copolymer, N-lauryl alanine, N, N, N-trimethylaminopropionic acid,
N, N, N-trihydroxyethylaminopropionic acid, N-hexyl N, N-dimethylaminoacetic acid, 1-
And amphoteric surfactants such as (2-carboxyethyl) pyridinium betaine and lecithin. These surfactants may be used as a mixture of two or more kinds, and the amount used is 0.1 to 10% by weight based on the total weight of the composition of the present invention.

When the microencapsulated material thus obtained is prepared as a solid preparation, it is dried and solidified by freeze-drying, spray-drying, drying under reduced pressure, etc., and if necessary, a solvent, a dispersing agent and the like. , A binder, a surfactant, a carrier, a stabilizer, a fragrance, a dye, and the like. When the microencapsulated product is prepared as a liquid preparation, the microencapsulated product may contain, as necessary, a solvent, a dispersant, a surfactant, a thickener, an antifreezing agent, water, a preservative,
Stabilizers, fragrances, dyes and the like are added.

The composition of the present invention can also be produced by the following method. The dispersant is mixed with water and / or a polyhydric alcohol to prepare an aqueous solution containing the dispersant. Next, a dispersion obtained by dispersing the colored balls in a polyvalent isocyanate and an insulating liquid by mixing a solvent or the like as necessary is added to a dispersant aqueous solution, and deflocculated by a peptizer. Examples of the peptizer used at this time include a high-speed rotating high-shear type agitator / peptizer, a dissolver, a colloid mill, a homogenizer, an ultrasonic peptizer and the like. K. Auto homomixer, T.I. K. Homomic line flow, ultra homomixer, NNK colloid mill and the like can be mentioned. The number of revolutions during peptization varies depending on the type and structure of the peptizer and the type of peptized liquid.
00 to 10000 rpm, preferably 2000 to 800 rpm
0 rpm, and the temperature during peptization is usually 5 to 50 ° C. The peptizing time may vary depending on the type and structure of the peptizer and the type of the deflocculant, but is usually 0.01 to 0.3 hours, preferably 0.02 to 0.15 hours. Also,
The size of the peptized oil droplet particles can be adjusted in the range of about 0.1 to 300 μm, depending on the peptization strength and the amount of the dispersant added, but is preferably adjusted to about 10 to 200 μm. The mixing time at this time is usually 1 to 48 hours, and the mixing temperature is usually 40 to 80 ° C, preferably 50 to 70 ° C. The stirring conditions during mixing are as follows:
rpm, preferably 50 to 150 rpm, and examples of commonly used stirrers include a chemical mixer and a three-one motor.

The microcapsules for display obtained as described above are separated from the aqueous phase, washed with water and dried. This operation for separation and drying can be performed by a conventional method, for example, a method of drying a slurry containing microcapsule-shaped display capsules.

Examples of the binder used in the composition of the present invention include inorganic binders, natural organic binders, semi-synthetic binders, synthetic resin binders, waxes and the like. Examples of the inorganic binder include bentonite, montmorillonite, water glass, and colloidal silica. Examples of the natural organic binder include starch, dextrin, casein, gelatin, glue, agar, gum arabic, corn starch, natural rubber, pulp solution and the like. As a semi-synthetic binder, carboxymethylcellulose, carboxymethylcellulose sodium salt, hydroxypropylmethylcellulose, nitrocellulose, cellulose acetate, methylcellulose,
Cellulose binders such as ethyl cellulose and hydroxypropyl cellulose, and lignin binders such as lignin, sodium ligninsulfonate and ammonium ligninsulfonate. Examples of synthetic resin binders include polyolefins such as high-density polyethylene, low-density polyethylene, and polypropylene; halogenated polyolefins such as polychloroethylene and polychlorinated propylene; acrylic polymers such as polyacrylonitrile and polymethyl methacrylate; polystyrene; acrylonitrile -Polystyrene-butadiene copolymer, polyvinyl chloride, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, vinyl polymers such as chlorinated vinyl chloride, polyvinyl ether, polyvinylidene chloride, ketone-formalin resin, phenoxy resin , Polybutadiene, polyisobutylene, polyisoprene and other synthetic rubbers, silicone resins, polyvinylidene fluoride, polytrifluoroethylene and other fluorocarbon resins, polyacetal and other acetal trees Polyesters such as nylon 6, nylon 66, polyethylene terephthalate, olefin oxides such as polyamide, polyimide, polyethylene oxide and polyphenylene oxide; carbonate resins such as polycarbonate; polysulfone resins; polyurethanes such as polyurethane and polyurethane urea; epoxy resins; Resin, melamine resin, maleic acid resin, urea resin, polyvinylpyrrolidone and the like. Examples of the wax include natural wax, petroleum wax, and synthetic wax. Examples of natural waxes include candelilla wax, carnauba wax, rice wax, wood wax, jojoba oil, beeswax, lanolin, whale wax,
Tallow, ozokerite, ceresin and the like can be mentioned. Examples of the petroleum wax include paraffin wax and microcrystalline wax. Examples of the synthetic wax include montan wax, polyethylene wax, Fischer-Tropsch wax, Sasol wax, hardened castor oil, 12-hydroxystearic acid, stearic acid, stearyl alcohol, laurone,
Examples include stearone, isopropyl myristate, glycerin fatty acid ester, glycol fatty acid ester, and sorbitan fatty acid ester.

When the binder used in the composition of the present invention is water-soluble, it may be dissolved in water and added as an aqueous solution, added as a powder, or melted by heating. It may be used as an emulsion or as an emulsion in which these fine particles are dispersed in water. When the binder is insoluble in water, it is added as an emulsion dispersed in water, used as a melt melted by heating, used as an emulsion in which these fine particles are dispersed in water, or dissolved in an organic solvent. It is preferable to use them. Two or more kinds of binders may be mixed and used in an arbitrary ratio. The amount of the binder may vary depending on the type of the binder, but is usually 0.1 to 40% by weight, preferably 0.5 to 30% by weight based on the total weight of the composition of the present invention.

Further, the electrode used to drive the colored ball needs to be light-transmitting so that the colored layer formed on the surface of the minute ball can be observed from the observation side. For this reason, SnO2, TiO2, ZnO, ITO
And the like.

The substrate (light transmitting film) is not particularly limited as long as it needs to be optically transparent in order to display the colored layer of the colored ball and has sufficient strength as a panel. Although not limited thereto, for example, a hard resin such as polyimide, polycarbonate, acrylic, polyethylene terephthalate, polyethylene, or polystyrene, or silicone rubber can be used.

The image display medium of the present invention can be applied to a light receiving type display device for displaying image information such as a character, a graphic, and a video by utilizing the rotation of a colored ball. Further, the present invention can be applied to a paper display which can be viewed like paper, can be moved like paper, can write an image, can copy an image, can read an image, and can erase an image.

Through the above steps, it is possible to manufacture an image display medium for displaying images by rotating the colored balls.

[0042]

EXAMPLES Examples will be shown below, but the present invention is not limited to these examples. In the examples and comparative examples, “parts” means parts by weight.

Example 1 Diameter of two hemispherical colored black and white colors in a solution obtained by mixing 3 parts of tolylene diisocyanate / 10 parts of adduct of trimethylolpropane and 10 parts of silicone oil with 30 parts of ethyl acetate. A dispersion was prepared by dispersing 4 parts of 50-60 micron zirconia balls. 20 parts of this dispersion was mixed with 120 parts of a 2 wt% aqueous solution of polyvinyl alcohol (degree of polymerization 900) for 2 minutes and emulsified and dispersed to form an oil-in-water emulsion having an average particle size of 60 to 70 μm. To this, 300 parts of a 1% by weight propylamine aqueous solution was added, and the mixture was stirred for 3 hours in a constant temperature bath at 50 ° C. to perform an interfacial polymerization reaction and simultaneously remove the solvent. The aqueous phase was removed from the obtained interfacially polymerized particles using a centrifuge, and instead, washing water was added, followed by stirring and redispersion. This washing operation was performed six times, and the capsule particles were taken out as a powder with a freeze dryer. 10 parts of the capsule particles obtained as above
An image display medium was prepared by dispersing in 50 parts of a 50% aqueous solution of polyvinylpyrrolidone and sandwiching between two film substrates each having a transparent electrode pattern formed thereon. By applying an electric field according to the image signal between the electrodes, the colored ball was rotated and the black portion was visually recognized.

Example 2 Sumidur N-3200 (manufactured by Sumitomo Bayer Urethane,
In a solution in which 6 parts by weight of a burette-type aliphatic isocyanate prepolymer) and 5 parts of Hisol SAS-296 (manufactured by Nippon Petrochemical Co., Ltd., an aromatic high boiling point solvent) are mixed with 40 parts of ethyl acetate, two black and white hemispheres are formed. Color-coded diameter 50 ~
A dispersion was prepared by dispersing 5 parts of zirconia balls of 60 microns. The dispersion 10 was added to 100 parts of a 5% aqueous solution of polyvinyl alcohol GL-05 (manufactured by Nippon Synthetic Chemical Co., Ltd.).
0 parts were emulsified and dispersed to form an oil-in-water emulsion having an average particle size of 70 to 80 µm. To this, 300 parts of a 1% by weight aqueous solution of diethylenetriamine was added, and the mixture was stirred in a thermostat at 60 ° C. for 1 hour to carry out an interfacial polymerization reaction and simultaneously remove the solvent. The aqueous phase was removed from the obtained interfacially polymerized particles using a centrifuge, and instead, washing water was added, followed by stirring and redispersion. This washing operation was performed six times, and the capsule particles were taken out as a powder with a freeze dryer. An image display medium was prepared by dispersing 10 parts of the capsule particles obtained as described above in 50 parts of an aqueous solution of 10% polyvinylpyrrolidone and sandwiching each between two film substrates on which a transparent electrode pattern was formed. . By applying an electric field according to the image signal between the electrodes, the colored ball was rotated and the black portion was visually recognized.

Example 3 10 parts by weight of Takenate 110N (manufactured by Takeda Pharmaceutical, aliphatic isocyanate prepolymer) and Hisol SAS-2
96 (Nippon Petrochemical, aromatic high-boiling solvent) 6 parts 4
A dispersion liquid was prepared by dispersing 5 parts of zirconia balls having a diameter of 50 to 60 microns, which were color-coded in two colors black and white and hemispherical in a solution mixed with 0 parts of ethyl acetate. PH was added to 80 parts of a 5% aqueous solution of polyvinyl alcohol GL-05 (manufactured by Nippon Synthetic Chemical Co., Ltd.) and 20 parts of a 5% aqueous solution of sodium salt of polyacrylic acid (manufactured by Nippon Pure Chemical Industries, Julimer AC-103).
Was adjusted to 8 and emulsified and dispersed to form an oil-in-water emulsion having an average particle size of 90 to 100 μm. 1% by weight diethylenetriamine aqueous solution 3
After adding 00 parts, the mixture was stirred in a thermostat at 60 ° C. for 1 hour to carry out the interfacial polymerization reaction and at the same time to remove the solvent. The aqueous phase was removed from the obtained interfacially polymerized particles using a centrifuge, and instead, washing water was added, followed by stirring and redispersion. This washing operation was performed six times, and the capsule particles were taken out as a powder with a freeze dryer. Capsule particles 10 obtained as described above
An image display medium was prepared by dispersing the portions in 50 parts of a 10% aqueous solution of polyvinylpyrrolidone and sandwiching them between two film substrates each having a transparent electrode pattern formed thereon. By applying an electric field according to the image signal between the electrodes, the colored ball was rotated and the black portion was visually recognized.

COMPARATIVE EXAMPLE 1 In a solution obtained by mixing 40 parts of silicone oil with 10 parts of ethyl acetate, a diameter of 50 to 50 was classified into two black and white colors.
A dispersion was prepared by dispersing 4 parts of 60 micron zirconia balls. On the other hand, the above dispersion was added to 100 parts of a 5% acid-treated gelatin aqueous solution adjusted to pH 9.0 and a temperature of 50 ° C., followed by stirring and emulsification until the particle diameter became about 120 to 130 μm. Next, 50 parts of a 5% gum arabic aqueous solution was added to the above emulsion, and the mixture was stirred at a temperature of 40 ° C.
The 5% acetic acid solution was slowly added until the pH was 4.0. After further lowering the temperature to 5 ° C. and stirring for 4 hours, 3
After adding 4 parts of a 7% aqueous formaldehyde solution, the mixture was stirred for 2 hours to raise the pH to 9, thereby completing the encapsulation. Remove the aqueous phase from the resulting capsule using a centrifuge,
Instead, washing water was added, followed by stirring and redispersion. This washing operation was performed six times, and the capsule particles were taken out as a powder with a freeze dryer. 10 parts of the obtained capsule particles are 10%
An image display medium was prepared by dispersing in 50 parts of an aqueous solution of polyvinylpyrrolidone and sandwiching between two film substrates each having a transparent electrode pattern formed thereon. The colored ball was rotated by applying an electric field according to the image signal between the electrodes, but the black portion could not be clearly recognized because most of the microcapsules were broken.

[0047]

As described in detail above, the present invention has the following functions and effects. 1. By sandwiching the display capsule containing the colored balls between the two film substrates on which the transparent electrode patterns are formed, the flexibility of the display device can be sufficiently maintained. 2. Since the film holding the ball is used in a non-swelled state, it has high strength and is hard to break.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4G005 AA01 AB12 AB15 AB27 BA02 BB05 BB06 BB24 DA01W DA12X DA13W DB06W DB12W DB13W DB16W DB27W DC09W DC12W DC18W DC18Y DC34Y DC42Y DC46Y DC52W DC54W DC61Y DD68DDDYDDDDW DDDD DDW DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DD DE01W DE01Y DE02X DE04W DE05W DE06W EA09 5C094 AA37 AA60 BA09 BA75 BA76 BA84 FB04 FB15 GB10

Claims (4)

[Claims] 1. A colored ball having a surface constituted by two or more regions having different optical characteristics and charging characteristics, and a display microcapsule containing an insulating liquid are held on a support, and added to the colored ball. An image display medium for displaying an image by rotating a colored ball by controlling an applied electric field, wherein the colored ball and the insulating liquid are covered with a resin shell formed by using an interfacial polymerization method. Image display medium characterized by forming microcapsules for use. 2. A dispersion obtained by dispersing the colored balls in a liquid mixture of the insulating liquid and a first reactive component for forming a resin outer shell is used as an interface with the first reactive component. An image display characterized by producing a microcapsule for display covering the insulating liquid and the colored ball by adding it to an aqueous solution containing a second reactive component that forms a resin coating by a polymerization method. The method of manufacturing the medium. 3. The method according to claim 1, wherein the first reactive component is selected from polyhydric isocyanates and / or polybasic acid chlorides, and the second reactive component is selected from polyhydric amines and / or polyhydric alcohols. A method for manufacturing an image display medium. 4. The image display medium according to claim 1, wherein the particle diameter of the display microcapsules is 1.0 to 2.0 times the particle diameter of the colored balls.