JP2005091572A - Particle supply method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a particle supply method of efficiently and uniformly charging particles between opposite substrates. <P>SOLUTION: A particle supply device 30 includes a hopper 34 filled with mixed particles 32 and a vibration exciter 36 fitted to the hopper 34, and a mesh-shaped particle supply opening 38 is provided at the lower portion of the hopper 34. A mask member 40 is mounted on a substrate 14 where a spacer 16 is formed and while the vibration exciter 36 excites the whole hopper 34, the substrate 14 where the spacer 16 is formed is moved at a fixed speed. Consequently, the mixed particles 32 fall in a recessed part 42 formed of the spacer 16 and substrate 14 from the particle supply opening 38 and the recessed part is filled with the particle. Then mixed particles 32 left on the mask member 40 is made to fall in the recessed part 42 by means of a blade 44. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a particle supply method, and more particularly to a particle supply method in the manufacture of an image display medium that displays an image by moving colored particles by applying a voltage according to an image between substrates.

  2. Description of the Related Art Conventionally, an electronic paper technique for displaying a desired image on a display element using an electric force is known. Such electronic paper technology is roughly classified into liquid display elements or liquids in which solid display elements are dispersed, such as those using electrophoresis, thermal rewritable technology, liquid crystal, electrochromy, and the like. Conductive particles and insulating particles having different colors as display elements are enclosed between a substrate encapsulated between opposing substrates and a pair of substrates in which an electrode and a dielectric layer are sequentially stacked on a support substrate. There is a configuration. Among these, in the latter display medium, due to the electric field applied between the substrates, one of the conductive particles and the frictionally charged particles moves to one of the pair of substrates, and the other moves to the other of the pair of substrates. An image is formed by the contrast of the colors. This image is retained even when the application of the electric field between the substrates is stopped. Further, the image formation can be repeated by switching the applied electric field.

  2. Description of the Related Art Generally, a manufacturing method of electronic paper having a configuration in which a display liquid in which liquid display elements or display elements are dispersed in a liquid is sealed between the opposite substrates is known. For example, a liquid crystal display is produced by evacuating a substrate and sucking a display liquid in which liquid display elements or display elements are dispersed in the liquid between the substrates.

  However, the latter method is similar to the above-described method for manufacturing electronic paper in which a powdery display element such as toner is enclosed between opposing substrates, that is, vacuum is drawn by dispersing powder in a dispersion medium. Even if an attempt is made to apply a method of evaporating the dispersion medium after being injected between the substrates, it is difficult and impractical to completely evaporate the dispersion medium filled between the substrates.

  For this reason, in Patent Document 1, as a method of enclosing powder display particles between opposing substrates, the substrate is charged, and the particles charged with the opposite polarity are electrostatically attracted and applied to the substrate side. How to do is described.

Patent Document 2 introduces a method of sieving using a screen as a method of enclosing two kinds of mixed particles at once between substrates.
JP 2001-92388 A JP 2002-72257 A

  However, in the technique described in Patent Document 1, in the case of two types of particles having different charging characteristics, it is difficult to precisely align the charged particle values for electrostatic coating, and electrostatic coating is repeated twice. There was a problem that it was necessary.

  Further, with the technique described in Patent Document 2, it is difficult to enclose uniform particles unless the method of spreading and sieving particles on the screen is precisely controlled. In addition, there is a method of supplying mixed particles in a sprayed state to a closed booth and dropping and filling the substrate, but in the case of insulating particles, adhesion to the booth inner wall is more noticeable than filling. There was a problem.

  The present invention has been made in view of the above problems, and an object thereof is to provide a particle supply method capable of supplying particles uniformly and efficiently onto a substrate.

  In order to solve the above-described problem, the invention according to claim 1 is characterized in that the pair of substrates are arranged so as to be movable, and the pair of substrates are movable in accordance with an electric field formed by a voltage applied between the pair of substrates. An image including a plurality of types of particle groups having different colors and charging characteristics enclosed between substrates, and a gap member that holds a gap between the pair of substrates and partitions the pair of substrates into a plurality of cells. A particle supply method in manufacturing a display medium, wherein the particle group is dropped from the particle supply port while vibrating a filling unit filled with the plurality of types of particle groups and provided with a particle supply port at a lower portion. Thus, the plurality of types of particle groups are supplied onto one of the pair of substrates on which the gap member is formed.

  The present invention relates to particles in the manufacture of an image display medium having a structure in which a plurality of types of particles having different colors and charging characteristics are enclosed in a cell formed by a pair of substrates and a gap member provided between the substrates. It is a supply method.

  An image display medium is manufactured by forming a gap member on one of a pair of substrates, supplying a group of particles into a recess formed by the one substrate and the gap member, and bonding the other substrate together. can do.

  According to the present invention, in the step of supplying the particle group onto the one substrate on which the gap member is formed, the filling means in which a plurality of types of particle groups are filled and the particle supply port is provided below is vibrated. The particle group is supplied into the recess by dropping the particle group from the particle supply port.

  In this way, by supplying the particle group onto the substrate by dropping the particle while oscillating the filling means filled with the particle group, the particle is efficiently and uniformly applied to the substrate without requiring a complicated process. Can be supplied on top.

  In addition, as described in claim 2, after supplying the plurality of types of particle groups into a recess formed by the one substrate and the gap member, the particle groups remaining on the gap member are separated by a blade. It is preferable to drop into the recess.

  Thus, by dropping the particle group remaining on the gap member into the recess, the amount of the particle group filled in the recess can be made closer to the predetermined amount to be supplied.

  According to a third aspect of the present invention, after the mask member having substantially the same shape as the gap member is placed on the gap member, the plurality of types of particle groups are supplied onto the one substrate. May be.

  The mask member has a shape that is substantially the same shape as the gap member when viewed in plan, that is, a shape in which the shape of the opening portion is the same shape. When the mask member is placed on the gap member, it is preferable that the gap member is completely hidden when viewed in plan. Thereby, the particles fall on the mask member, and no particles remain on the gap member. Accordingly, it is possible to prevent the image display medium having the display performance from being deteriorated by bonding the other substrate while the particles remain on the gap member.

  According to a fourth aspect of the present invention, the particle supply port is preferably composed of a plurality of openings having a predetermined shape. Thus, particles can be supplied more uniformly by making the particle supply port mesh-shaped.

  According to the present invention, there is an effect that particles can be efficiently and uniformly supplied onto a substrate.

  Embodiments of the present invention will be described below.

  As shown in FIG. 1, the image display medium 10 includes a pair of substrates 12, 14 disposed opposite to each other, a spacer 16 formed on the substrate 14, and an interior between the substrates 12, 14 and the spacer 16. For example, positively charged black particles 18 and negatively charged white particles 20 are included in the space.

  The substrate 12 includes a transparent support base 12A, a transparent electrode 12B formed thereon, and a dielectric film 12C formed on the transparent electrode 12B, and is light transmissive.

  The substrate 14 includes a support base 14A, an electrode 14B formed thereon, and a dielectric film 14C formed on the electrode 14B. The transparent electrode 12B and the electrode 14B can have, for example, a simple matrix structure or an active matrix structure, and are connected to voltage application means (not shown).

  For example, as shown in FIG. 2, the spacer 16 has a lattice-like shape when seen in a plan view, and the spacer 16 holds the substrate 12 and the substrate 14 at a constant distance. The space is divided into a plurality of cells 22.

  In this image display medium 10, after preparing a substrate 12, forming an electrode 14B on a support base 14A, a spacer 16 is formed on the electrode 14B using a dry film, and the portion other than the portion where the spacer 16 of the electrode 14B is formed A dielectric film 14C is formed on the portion of the substrate, black particles 18 and white particles 20 are supplied to a space formed by the spacer 16 and the substrate 14, an adhesive is applied on the spacer 16, and then the substrate 12 is attached to the spacer. 16 and can be produced by solidifying or curing the adhesive. A method for supplying particles will be described later.

  In such an image display medium 10, for example, by applying a predetermined positive voltage to the transparent electrode 12 </ b> B with reference to the electrode 14 </ b> B by a voltage applying unit (not shown), the negatively charged white particles 20 move to the substrate 12 side. At the same time, the positively charged black particles 18 move toward the substrate 14 and are displayed in white. Note that the substrate 12 and the substrate 14 themselves may be provided externally without providing electrodes.

  Further, by applying a predetermined negative voltage to the transparent electrode 12B with the electrode 14B as a reference, the positively charged black particles 18 move to the substrate 12 side, and the negatively charged white particles 20 move to the substrate 14 side. And it is displayed in black.

  Therefore, by applying a voltage according to the image between the substrates, the particles can be moved according to the image and a desired image can be displayed.

  Even after the application of the voltage is stopped, the particles remain attached to the substrate due to the mirror image force and the display is maintained.

  Next, an example of the material of each part constituting the image display medium 10 will be described.

  Examples of the transparent support base 12A and the support base 14A include glass and plastics such as polycarbonate resin, acrylic resin, polyimide resin, and polyester resin.

  The transparent electrode 12B and the electrode 14B include oxides such as indium, tin, cadmium and antimony, composite oxides such as ITO, metals such as gold, silver, copper and nickel, and organic conductive materials such as polypyrrole and polythiophene. Etc. can be used. These can be used as a single layer film, a mixed film, or a composite film, and can be formed by vapor deposition, sputtering, coating, or the like. The thickness is usually 100 to 2000 angstroms according to the vapor deposition method and the sputtering method. The electrodes can be formed in a desired pattern, for example, a matrix by a conventionally known means such as etching of a conventional liquid crystal display element or a printed board.

  As the dielectric films 12C and 14C, polycarbonate, polyester, polyimide, epoxy, polyisocyanate, polyamide, polyvinyl alcohol, polybutadiene, polymethyl methacrylate, copolymer nylon, ultraviolet curable acrylic resin, amorphous Teflon (R), or the like is used. be able to. Since the dielectric film may affect the charging characteristics and fluidity of the particles, it is appropriately selected according to the composition of the particles. Since the substrate 12 needs to transmit light as a substrate on the display side, it is preferable to use a transparent material among the above materials.

  An anchor coating agent may be used for improving adhesion to the substrate. Examples of the anchor coating agent include polyurethane, polyamide, polyethyleneimine, amorphous polyester, hydrophilic polyester, ionic polymer complex, and alkyl titanate resin. These may be used alone or in combination. Moreover, these copolymers can also be used.

  The spacer 16 is formed of an insulating material. Specifically, the spacer 16 can be formed of a thermoplastic resin, a thermosetting resin, an electron beam curable resin, a photocurable resin, rubber, or the like. Among these, a photopolymerizable layer, a support layer, and, if necessary, an electron beam curable resin such as a dry film resist composed of a protective layer, and a photo curable resin can be suitably used. High precision spacers can be created. For the development of a dry film resist, a case of using an alkaline solution and a case of using a solvent are known, and both can be used in the present invention. The thickness of the film is generally 50 to 300 μm.

  As the two types of black particles 18 and white particles 20 having different colors, volume resistivity and charging characteristics used in the present invention, a combination of conductive particles and insulating particles, positively charged insulating particles and negative particles are used. The combination with the insulating particle | grains to charge is mentioned.

  The conductive particles include metal particles such as carbon black, nickel, silver, gold, and tin, conductive metal oxide particles such as ferrite, ITO, indium oxide, zinc oxide, and antimony oxide-doped tin oxide, and insulating particles. Examples thereof include those having a surface coated with a metal or a conductive metal oxide, carbon black, metal particles or particles containing a conductive metal oxide in a thermoplastic or thermosetting resin.

  Insulating particles include glass beads, insulating metal oxide particles such as alumina and titanium oxide, thermoplastic or thermosetting resin particles, those having a colorant fixed on the surface of these resin particles, heat Examples thereof include particles containing an insulating colorant in a plastic or thermosetting resin.

  Examples of the thermoplastic resin used in the production of particles include styrenes such as styrene and chlorostyrene, monoolefins such as ethylene, propylene, butylene, and isoprene, vinyls such as vinyl acetate, vinyl propionate, vinyl benzoate, and vinyl butyrate. Α-methylene aliphatic monocarboxylic acid such as ester, methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dodecyl methacrylate Homopolymers or copolymers of vinyl ethers such as acid esters, vinyl methyl ether, vinyl ethyl ether, vinyl butyl ether, vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, vinyl isopropenyl ketone It can be exemplified. In addition, as thermosetting resins used for the production of particles, crosslinked resins mainly composed of divinylbenzene and crosslinked resins such as crosslinked polymethyl methacrylate, phenol resins, urea resins, melamine resins, polyester resins, silicones Examples thereof include resins. Particularly representative binder resins include polystyrene, styrene-alkyl acrylate copolymer, styrene-alkyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer. Examples thereof include a polymer, polyethylene, polypropylene, polyester, polyurethane, epoxy resin, silicone resin, polyamide, modified rosin, and paraffin wax.

  As the colorant, organic or inorganic pigments, oil-soluble dyes, etc. can be used, magnetic powders such as magnetite and ferrite, carbon black, titanium oxide, magnesium oxide, zinc oxide, phthalocyanine copper-based cyan colorant, Known colorants such as an azo yellow color material, an azo magenta color material, a quinacridone magenta color material, a red color material, a green color material, and a blue color material can be given. Specifically, aniline blue, calcoil blue, chrome yellow, ultramarine blue, DuPont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green oxalate, lamp black, rose bengal, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 57: 1, C.I. I. Pigment yellow 97, C.I. Blue 15: 1, C.I. I. Pigment Blue 15: 3, etc. can be exemplified as typical ones. Also, porous sponge-like particles or hollow particles enclosing air can be used as white particles. These are selected so that the two types of particles have different color tones.

  The shape of the particle is not particularly limited, but in the case of a true sphere, the contact between the particles is almost a point contact, and the contact between the particle and the inner surface of the substrate is almost a point contact. The adhesion force based on the van der Walls force with the surface is small. Therefore, even if there is a dielectric film on the inside of the substrate, the charged particles can be smoothly moved in the substrate by the electric field. In order to form spherical particles, suspension polymerization, emulsion polymerization, dispersion polymerization or the like can be used.

  The primary particle size of the particles is generally 1-1000 μm, preferably 5-50 μm, but is not limited thereto. In order to obtain a high contrast, it is preferable that the particle diameters of the two types of particles are substantially the same. In this way, a situation in which large particles are surrounded by small particles and the original color density of the large particles is reduced is avoided.

  If necessary, an external additive may be attached to the surface of the insulating particles. The color of the external additive is preferably white or transparent so as not to affect the color of the particles.

  As the external additive, inorganic fine particles such as metal oxides such as silicon oxide (silica), titanium oxide, and alumina are used. In order to adjust the chargeability, fluidity, environment dependency, etc. of the fine particles, these can be surface-treated with a coupling agent or silicone oil.

  Coupling agents include positively chargeable ones such as aminosilane coupling agents, aminotitanium coupling agents, nitrile coupling agents, and silanes that do not contain nitrogen atoms (consisting of atoms other than nitrogen). There are negatively charged ones such as coupling agents, titanium-based coupling agents, epoxy silane coupling agents, and acrylic silane coupling agents. Similarly, silicone oil includes positively chargeable ones such as amino-modified silicone oil, dimethyl silicone oil, alkyl-modified silicone oil, α-methylsulfone-modified silicone oil, methylphenyl silicone oil, chlorophenyl silicone oil, fluorine-modified. Examples include negatively chargeable ones such as silicone oil. These are selected according to the desired resistance of the external additive.

Among such external additives, well-known hydrophobic silica and hydrophobic titanium oxide are preferable, and in particular, TiO (OH) ₂ described in JP-A-10-3177 and a silane coupling agent are used. Titanium compounds obtained by reaction with silane compounds are preferred. As the silane compound, any of chlorosilane, alkoxysilane, silazane, and a special silylating agent can be used. This titanium compound is produced by reacting TiO (OH) ₂ produced in a wet process with a silane compound or silicone oil and drying it. Since it does not pass through the firing step of several hundred degrees, strong bonds between Ti are not formed, there is no aggregation, and the fine particles are almost in the state of primary particles. Furthermore, since the silane compound or silicone oil reacts directly with TiO (OH) ₂ , the treatment amount of the silane compound or silicone oil can be increased, and the charging characteristics can be controlled by adjusting the treatment amount of the silane compound. The charging ability that can be imparted and can be imparted can be significantly improved over that of conventional titanium oxide.

  The primary particles of the external additive are generally 5 to 100 nm, preferably 10 to 50 nm, but are not limited thereto.

  The blending ratio of the external additive and the particles is appropriately adjusted based on the balance between the particle size of the particles and the particle size of the external additive. If the amount of the external additive added is too large, a part of the external additive is liberated from the particle surface and adheres to the surface of the other particle, so that desired charging characteristics cannot be obtained. In general, the amount of the external additive is 0.01 to 3 parts by weight, more preferably 0.05 to 1 part by weight with respect to 100 parts by weight of the particles.

  When two types of insulating particles are used, the composition of the particles to be combined, the mixing ratio of the particles, the presence or absence of the external additive, the composition of the external additive, and the like are selected so that the desired charging characteristics can be obtained.

  The contrast depends not only on the particle size of the two types of particles but also on the mixing ratio of these particles. In order to obtain a high contrast, it is desirable to determine the mixing ratio so that the surface areas of the two types of particles are the same. If the ratio deviates greatly from this ratio, the color of particles having a large ratio is emphasized. However, this is not the case when the color tone of the two types of particles is changed to a dark color tone and a light color tone of similar colors, or when a color produced by mixing two types of particles is used for an image.

  The black particles 18 and the white particles 20 are enclosed in a cell 22 as an internal space formed by the pair of substrates 12 and 14 and the spacer 16, and the cell 22 is sealed. As a sealing method, the spacer 16 is formed on one substrate 14 of a pair of substrates and fixed to the other substrate 12 with a resin, and the outer surface of the spacer 16 and the pair of substrates 12 and 14 are formed. A method of filling the space with resin, a method of pushing the elastic member into the space formed by the outer surface of the spacer 16 and the pair of substrates, and forming the spacer 16 on one substrate 14 of the pair of substrates. For example, a method of sandwiching an elastic member between an end of the spacer 16 on the other substrate 12 side and the other substrate 14 may be used.

  In order to form the spacer 16 on the substrate 14, a dry resist film is thermocompression-bonded on the electrode 14B on the support base 14A using a hot laminator or the like, a mask pattern is overlaid on the dry resist film, and then exposed. A method of peeling the support layer of the film and developing with a developer can be used. This method may be repeated until the spacer 16 has the desired thickness. After the formation of the spacer 16, the dielectric film 14C is formed on a portion other than the portion on the electrode 14B where the spacer 16 is formed.

  The resin used for sealing is preferably a moisture-resistant resin, and specifically includes a thermoplastic resin, a thermosetting resin, an electron beam curable resin (for example, an ultraviolet curable resin), a photocurable resin, and the like. These may be used alone or in combination. Two or more types of resins (for example, thermoplastic resins) may be used.

  Examples of thermoplastic resins include polyolefins such as polypropylene, polyethylene, and ethylene-propylene copolymers, polyesters, polyamides, ionomers, polyvinyl acetates, vinyl resins such as ethylene-vinyl acetate copolymers, acrylic acid esters, and methacrylic acid esters. Acrylic resins, polyvinyl acetals, phenols, modified epoxy resins, amorphous polyesters, and copolymers and mixtures thereof. Among these, a polymer containing 60 mol% or more of at least one component among acrylonitrile component, vinyl alcohol component, vinyl butyral component, cellulose-based component, aramid component, and vinylidene halide component, and a mixture thereof are preferable.

  Examples of the polymer having acrylonitrile as a monomer include polyacrylonitrile and acrylonitrile-butadiene copolymer. Polyvinyl alcohol etc. are mentioned as a polymer which uses vinyl alcohol as a monomer. Examples of the polymer having vinyl butyral as a monomer include polyvinyl butyral. Polyvinyl butyral may be used in combination with an epoxy resin. Examples of the polymer having vinylidene halide as a monomer include PVDC (polyvinylidene chloride), PVDC-VC (vinyl chloride) copolymer, PVDC-acrylonitrile copolymer, PVDC-acrylic acid ester copolymer, and vinylidene chloride. Examples thereof include multi-component copolymers containing several kinds of polymerizable monomers and PTFE.

  Examples of thermosetting resins include epoxy resins; guanamine resins; diallyl phthalate resins, vinyl ester resins, maleic acid resins, polyester resins such as unsaturated polyester resins; polyurethanes; polyimides; melamine resins; urea resins; acrylic resins; Examples thereof include alkyd resins; phenol resins; xylene resins; silicone resins; phenoxy ether-based crosslinked resins; and copolymers and mixtures thereof.

  Electron curable resins include epoxy resins such as epoxy acrylate, urethane acrylate, polyester acrylate, multifunctional acrylate, polyether acrylate, silicon acrylate, polybutadiene acrylate, unsaturated polyester / styrene, polyene / thiol, polystyryl methacrylate, UV Cured lacquers and their oligomers, copolymers and mixtures are preferably used.

  Examples of the photo-curing resin include an epoxy resin, a silicone resin, and an acrylic resin.

Among the electron beam curable resin and the photo curable resin, an epoxy resin is preferably used. The epoxy resin may be either a one-component type that cures with only one type of component or a two-component type that cures by mixing two types of components. In the case of a two-component type, two types of adhesive components are mixed. After tempering, it is necessary to remove air bubbles by degassing at a vacuum degree of 5.33 × 10 ³ Pa (400 mmHg) or less for 15 to 30 minutes.

  These resins can be supplied on the spacer 16 or between the spacer 16 and the substrate 12 by screen printing or dispenser.

  Further, in the present invention, a polymerization initiator chain transfer agent, a photosensitizer, a dye, a crosslinking agent, and the like can be appropriately added to the spacer 16 and the resin used for sealing.

  When an elastic member is used, a sealing member such as an O-ring can be used, and the materials include butyl rubber, nitrile rubber, chloroprene rubber, neoprene rubber, ethylene-propylene copolymer rubber, urethane rubber, silicone rubber, and fluoro rubber. (Viton) etc. are mentioned, but it is not limited to these.

  Moreover, when using an elastic member, the fixing means for fixing a pair of board | substrates 12 and 14 is used. Examples of the fixing means include a combination of a bolt and a nut, a clamp, a clip, a frame for fixing the substrate, and the like.

  Next, a method for supplying particles will be described.

  FIG. 3A shows a schematic configuration of the particle supply device 30. As shown in FIG. 3A, the particle supply device 30 includes a hopper 34 filled with mixed particles 32 including black particles 18 and white particles 20, a vibration device 36 attached to the top of the hopper 34, It is comprised including.

  In the lower part of the hopper 34, a particle supply port 38 for dropping the filled internal particles below the hopper 34 is provided.

  The particle supply port 38 depends on the particle diameter of the particle, but when the particle diameter is 5 to 50 μm, which is a preferable range as described above, one side is 10 to 200 μm, that is, one side has a particle diameter of 2 to 2. Although it is preferable to use a mesh member provided with a plurality of square-shaped openings having a length of 440 times, the present invention is not limited to this. The shape of the opening of the particle supply port 38 is not limited to a square, and may be a circle or a rectangle. Further, it is preferable that one side of the longer outer shape of the particle supply port 38 is longer than at least one side of the shorter side of the substrate 14. Thereby, the particles can be supplied onto the substrate by moving the particle supply device 30 only once on the substrate.

  Further, when the particles are supplied, if the particles adhere to the upper surface of the spacer 16 and the substrate 12 is fixed as it is, the display performance deteriorates. Therefore, as shown in FIG. It is preferable to supply particles by placing them on the surface.

  For example, when viewed in plan, the mask member 40 has a shape in which an opening that is slightly smaller than the opening of the spacer 16 is provided corresponding to the opening of the spacer 16. Thereby, since the upper surface of the spacer 16 is concealed by the mask member 40, it is possible to prevent particles from being placed on the upper surface of the spacer 16 when supplying the particles.

  The material of the hopper 34, the particle supply port 38, and the mask member 40 is preferably a conductive material, and may be a conductive resin in addition to a metal such as stainless steel, aluminum, or copper.

  When the particles are supplied onto the substrate 14 on which the spacer 16 is formed by the particle supply device 30 as described above, first, as shown in FIG. 3A, the mask member 40 is mounted on the substrate 14 on which the spacer 16 is formed. And a hopper 34 filled with the mixed particles 32 is disposed at a position 3 mm to 100 mm above.

  Then, the substrate 14 is moved at a constant speed in the direction of the arrow in the figure while the entire hopper 34 is vibrated by the vibration device 36 attached to the upper portion of the hopper 34. As a result, the hopper 34 vibrates and the mixed particles 32 sequentially drop from one end of the substrate 14 to the other end from the particle supply port 38, and are formed by the spacer 16 and the substrate 14. Particles are supplied to the recess 42.

  In this way, particles are dropped from the mesh-shaped particle supply port 38 while being supplied with the hopper 34 and supplied onto the substrate, so that solidification of the particles can be eliminated and the particles can be supplied uniformly. Further, since the mask member 40 is placed on the substrate 14, the particles that have not been supplied to the recess 42 remain only on the mask member 40, and no particles remain on the upper portion of the spacer 16.

  The moving speed of the hopper 34 is set to a speed at which a predetermined amount of the mixed particles 32 can be supplied to the concave portion. Further, instead of moving the substrate 14, the hopper 34 may be moved, or the substrate 14 and the hopper 34 may be relatively moved.

  Further, the strength of vibration applied to the hopper 34 by the vibration device 36 depends on the particle size, chargeability, fluidity of the mixed particles 32, and the amount of particles filled in the hopper 34. For example, the vibration frequency is 50 to 150 Hz, the impact The force is set to about 20 to 1000 N, but is not limited to this.

  After supplying the mixed particles 32 onto the substrate 14 in this way, as shown in FIG. 3B, the blade 44 is moved to the mask member 40 so as to drop the mixed particles 32 remaining on the mask member 40 into the recesses 42. The substrate 14 is moved in the direction of the arrow in the figure from one end of the substrate 14 toward the other end in a state of being in contact with the substrate 14 at a predetermined angle. Thereby, the particle | grains on the mask member 40 can be dropped in the recessed part 42, and the predetermined amount of particle | grains which should be supplied in the recessed part 42 can be supplied reliably.

  The blade 44 is preferably made of rubber such as silicone or viton. Further, the moving direction of the blade 44 may be either the wiper blade direction or the doctor blade direction, but the wiper blade direction is preferable. The moving speed of the blade 44 can be used at any speed, but is preferably in the range of 1 to 1000 mm / min.

  As described above, in the present embodiment, the particles are dropped from the mesh-shaped particle supply port 38 onto the substrate while vibrating the hopper 34 filled with the particles, so that the spacer 16 and the substrate 14 are formed. The particles are supplied into the recesses 42, and the blades 44 are further moved to drop the particles remaining on the mask member 40 into the recesses 42. For this reason, a predetermined amount of particles can be efficiently and uniformly supplied into each recess 42.

  Examples of the present invention will be described below. Unless otherwise specified, parts are parts by weight.

(Example 1)
After dissolving ilmenite in sulfuric acid, the iron content was separated, and the resulting TiOSO ₄ was hydrolyzed by adding water to produce TiO (OH) ₂ . Subsequently, 50 parts of isopropyltrimethoxysilane was added dropwise to 100 parts of TiO (OH) ₂ prepared in the above manner and dispersed in 500 cm ^{3 of} water while stirring at room temperature. Subsequently, the fine particles in the obtained liquid mixture were filtered, and washing with water was repeated. The titanium compound surface-treated with isopropyltrimethoxysilane thus obtained was dried at 150 ° C. and pulverized for 2 minutes using a sample mill to obtain an external additive having an average particle size of 30 nm.

  Volume average particles obtained by classifying 0.4 parts by weight of the above external additive into spherical particles of titanium oxide-containing crosslinked polymethylmethacrylate (manufactured by Sekisui Plastics Co., Ltd., Techpolymer MBX-20-White). In addition to 100 parts by weight of particles having a diameter of 20 μm, stirring was performed to obtain white particles 20.

  Further, as the black particles 18, particles having a volume average particle diameter of 20 μm obtained by classifying spherical particles of carbon-containing crosslinked polymethyl methacrylate (manufactured by Sekisui Plastics Co., Ltd., Techpolymer MBX-20-Black) are used. used.

  A transparent electrode 12B is formed by sputtering ITO on a transparent transparent support substrate 12A made of rectangular transparent glass having a thickness of 2 mm. Further, a polycarbonate resin (PC-made by Mitsubishi Gas Chemical Co., Ltd.) is added to 45 parts by weight of monochlorobenzene. Z) A solution having 5 parts by weight dissolved therein was dip coated and dried to form a dielectric film 12C having a thickness of 5 μm, and a substrate 12 was prepared.

A copper electrode was bonded to one surface of a rectangular epoxy support base 14A having a thickness of 5 mm to form an electrode 14B. A dry resist film (manufactured by Hitachi Chemical Co., Ltd., Photec H-9050, photosensitive layer 50 μm) was thermocompression bonded onto this electrode 14B using a hot laminator having a roll temperature of 110 ° C. On this dry resist film, a rectangular mask having a rectangular opening at the center and having the same size as the support base 14A was overlaid, and exposed to an irradiation energy of 100 mJ / cm ² with an ultrahigh pressure mercury lamp. Next, after the support layer of the dry resist film was peeled off, the film was developed with a sodium hydroxide solution to remove unexposed portions. This operation was repeated 6 times to form a uniform spacer 16 having a height of 300 μm and a width of 200 μm. Next, a portion of the copper electrode other than the portion where the spacer 16 is formed is dip-coated with a solution in which 5 parts by weight of a polycarbonate resin (PC-Z, manufactured by Mitsubishi Gas Chemical Company) is dissolved in 45 parts by weight of monochlorobenzene and dried. Then, a dielectric film 14C having a thickness of 5 μm was formed, and a substrate 14 was formed.

  The white particles 20 and the black particles 18 were mixed at a weight ratio of 2: 1, and the obtained mixed particles 32 were placed in a hopper 34 installed 10 mm above the substrate 14. A vibration device 36 having a vibration frequency of 100 Hz and an impact force of 500 N is attached above the hopper 34, and a stainless mesh having a square shape with a side of 40 μm as a particle supply port 38 is provided below the hopper 34. Attached.

A stainless steel mask member 40 is placed on the spacer 16, the substrate 14 is moved horizontally at a moving speed of 300 mm / min, and the excitation device 36 is activated when the end of the substrate 14 moves to the position of the particle supply port 38. did. As a result, vibration is applied to the hopper 34 with a vibration frequency of 100 Hz and an impact force of 500 N by the vibration device 36, and the mixed particles 32 in the hopper 34 are 6.7 mg / cm in the recess 42 formed by the substrate 14 and the spacer 16. Shake off at a rate of ² .

(Example 2)
After the mixed particles 32 are dropped and filled into the recesses 42 on the substrate 14 as in the first embodiment, a silicone blade 44 installed in the wiper direction with respect to the substrate 14 is brought into contact with the mask member 40. The mixture particles 32 were moved at a moving speed of 300 mm / min, and the mixed particles 32 remaining on the mask member 40 were dropped into the recesses 42.

(Comparative Example 1)
In the same manner as in Example 1, a substrate 14 on which a spacer 16 was formed and two kinds of particles were prepared.

  For supplying the particles, a conventionally known spray coating apparatus 100 as shown in FIG. 4 was used. The spray coating apparatus 100 includes a particle tank 102, a cyclone 104, an air pump 106, a sealed booth 108, and a nitrogen gas line 110.

  The particle tank 102 is filled with insulating mixed particles 32 in advance, and the mixed particles 32 are sucked through the cyclone 104 by the air pump 106 and supplied into the sealed booth 108.

  The cyclone 104 has a function of removing defective particles, dust, and the like from the sucked mixed particles 32. As a result, only normal particles are supplied into the sealed booth 108.

  Nitrogen is supplied into the sealed booth 108 through a nitrogen gas line 110. As a result, the mixed particles 32 supplied into the sealed booth 108 by the air pump 106 are in a sprayed state.

  Using such a spray coating apparatus 100, first, the substrate 14 on which the spacer 16 is formed is placed in the sealed booth 108, the air pump 106 is driven, and the mixed particles 32 are supplied into the sealed booth 108. The nitrogen gas line 110 was driven so that the supplied mixed particles 32 were in a sprayed state.

  Then, the driving of the air pump 106 and the nitrogen gas line 110 was stopped, and the mixed particles 32 in the sprayed state in the sealed booth 108 were naturally dropped onto the substrate 14, thereby filling the mixed particles 32 in the recess 42.

  For each of Examples 1 and 2 and Comparative Example 1, 10 substrates 14 filled with mixed particles 32 are prepared, and the mixed particles 32 filled in a predetermined measurement region of each substrate are collected by a suction nozzle. The weight was measured with a precision balance. The measurement area was a square area with a side of 2 cm, and five locations at the four corners and the center of the substrate 14 were used.

The measurement results are shown in FIG. In FIG. 5, the average value (mg / cm ² ) represents the average value of the filling amounts of all the measurement regions of the ten substrates, and the target value of the average value is 4 (mg / cm ² ). The target range of the variation was set to an average value ± 5%. The variation (%) represents the variation in the average value of the filling amount of each substrate, and the target value was set to 5% or less.

  As shown in FIG. 5, in the first and second embodiments, the average value of the filling amount and the variation in the filling amount between the substrates are closer to the target value. It was excellent. On the other hand, in Comparative Example 1, most of the particles were electrostatically attached to the inner wall of the sealed booth 108 and were hardly filled on the substrate, making measurement impossible.

It is sectional drawing of an image display medium. It is a top view of a spacer. It is a figure for demonstrating the particle | grain supply method. It is a schematic block diagram of the spray coating apparatus which concerns on a comparative example. It is a table | surface showing the measurement result in each Example.

Explanation of symbols

10 Image Display Medium 12 Substrate 12A Transparent Support Base 12B Transparent Electrode 12C Dielectric Film 14 Substrate 14A Support Base 14B Electrode 14C Dielectric Film 16 Spacer (Gap Member)
18 Black particle 20 White particle 22 Cell 30 Particle supply device 32 Mixed particle 34 Hopper (filling means)
36 Exciting device 38 Particle supply port 40 Mask member 42 Recess 44 Blade 100 Spray coating device 102 Particle tank 104 Cyclone 106 Air pump 108 Sealed booth 110 Nitrogen gas line

Claims (4)

A plurality of types having different colors and charging characteristics enclosed between the pair of substrates movably in response to an electric field formed by a pair of substrates arranged opposite to each other and a voltage applied between the pair of substrates. A particle supply method in the manufacture of an image display medium, comprising: a particle group; and a gap member that holds a gap between the pair of substrates and partitions the pair of substrates into a plurality of cells,
The pair of particles in which the gap member is formed by dropping the particle group from the particle supply port while oscillating a filling means filled with the plurality of types of particle groups and provided with a particle supply port in the lower part. A particle supply method comprising supplying the plurality of types of particle groups onto one of the substrates.   The particle group remaining on the gap member is dropped into the recess by a blade after the plurality of types of particle groups are supplied into the recess formed by the one substrate and the gap member. Item 2. A method of supplying particles according to Item 1.   3. The plurality of types of particle groups are supplied onto the one substrate after a mask member having substantially the same shape as the gap member is placed on the gap member. Particle supply method.   The particle supply method according to any one of claims 1 to 3, wherein the particle supply port includes a plurality of openings having a predetermined shape.

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