WO2013133047A1 - Particle dispersion for display, image display device, electronic appliance, medium for exhibition, and card medium - Google Patents

Particle dispersion for display, image display device, electronic appliance, medium for exhibition, and card medium Download PDF

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Publication number
WO2013133047A1
WO2013133047A1 PCT/JP2013/054578 JP2013054578W WO2013133047A1 WO 2013133047 A1 WO2013133047 A1 WO 2013133047A1 JP 2013054578 W JP2013054578 W JP 2013054578W WO 2013133047 A1 WO2013133047 A1 WO 2013133047A1
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Prior art keywords
display
particles
white
particle
dispersion
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PCT/JP2013/054578
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French (fr)
Japanese (ja)
Inventor
大谷　薫明
多田隈　芳夫
淳 川原
弘志 萱嶋
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富士フイルム株式会社
富士ゼロックス株式会社
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Publication of WO2013133047A1 publication Critical patent/WO2013133047A1/en

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    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/165—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on translational movement of particles in a fluid under the influence of an applied field
    • G02F1/166—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on translational movement of particles in a fluid under the influence of an applied field characterised by the electro-optical or magneto-optical effect
    • G02F1/167—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on translational movement of particles in a fluid under the influence of an applied field characterised by the electro-optical or magneto-optical effect by electrophoresis
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/165—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on translational movement of particles in a fluid under the influence of an applied field
    • G02F1/1675—Constructional details
    • G02F2001/1678—Constructional details characterised by the composition or particle type

Definitions

  • the present invention relates to a display particle dispersion used in an image display device capable of multicolor display, and an image display device having the same.
  • the present invention also relates to an electronic device including an image display device, a display medium, and a card medium.
  • a display technique using electrophoresis has been proposed as a display technique that can be rewritten repeatedly.
  • a display technique for example, an image display device having a configuration in which a dispersion liquid is sealed between a pair of substrates and particle groups made of charged particles are dispersed in the dispersion liquid is known.
  • a voltage corresponding to an image is applied between the substrates to move the charged particles and display the image as the color contrast of the particles (for example, Japanese Patent Application Laid-Open No. 2004-2004). No. 333589, JP 2005-107146, JP 2005-128141, and JP 2003-005228).
  • composite particles containing pigments such as titanium oxide particles as display white particles (see, for example, Japanese Patent Application Laid-Open Nos. 2007-041078 and 2007-033630).
  • the present invention has been made to solve the above-described problem, and a display particle dispersion having a high white display reflectance and suppressing the precipitation of display white particles, and an image display apparatus including the same. It is an issue to provide. Moreover, this invention makes it a subject to provide an electronic device provided with this image display apparatus, a display medium, and a card
  • Means for achieving the above object are as follows. ⁇ 1> A white particle for display containing a white pigment and a resin, wherein the content of the white pigment (mass of the white pigment / (total mass of the white pigment and the resin)) is 30% by mass or more and 90% by mass.
  • White particles for display having a volume average particle size of 100 nm to 500 nm and satisfying the following formula (1): Display colored particles that move in response to an electric field, two or more types of display colored particles excluding white, A dispersion medium for dispersing the display colored particles and the display white particles; It is a particle dispersion for display which has.
  • Formula (1) 400 ⁇ 6 kT / ( ⁇ d 3 ( ⁇ p ⁇ s) g) ⁇ 30
  • k represents the Boltzmann coefficient (J ⁇ K ⁇ 1 )
  • T represents the absolute temperature 298 (K)
  • d represents the volume average particle diameter (nm) of the white particles for display.
  • ⁇ p is . ⁇ s showing a specific gravity (g / cm 3) of the display for white particles exhibit specific gravity (g / cm 3) .g showing a gravity acceleration (m / s 2) of the dispersion medium.)
  • ⁇ 2> The display particle dispersion according to ⁇ 1>, wherein the white pigment is titanium oxide.
  • a moving speed ratio (moving speed Vw of the white particles for display / moving speed Vc of the colored particles for display) that moves according to the electric field between the white particles for display and the colored particles for display is 0.
  • ⁇ 4> The display particle dispersion according to any one of ⁇ 1> to ⁇ 3>, wherein the dispersion medium has a viscosity of 5 mPa ⁇ s or less.
  • ⁇ 5> The display particle dispersion according to any one of ⁇ 1> to ⁇ 4>, wherein the dispersion medium is silicone oil.
  • ⁇ 6> The display particle dispersion according to any one of ⁇ 1> to ⁇ 5>, wherein the white particles for display have a specific gravity of 2.1 g / cm 3 or more and 4.3 g / cm 3 or less.
  • ⁇ 7> The display particle dispersion according to any one of ⁇ 1> to ⁇ 6>, wherein the specific gravity of the dispersion medium is 0.6 g / cm 3 or more and 1.2 g / cm 3 or less.
  • ⁇ 8> a pair of substrates at least one of which has translucency;
  • ⁇ 9> An electronic device including the image display device according to ⁇ 8>.
  • ⁇ 10> An exhibition medium including the image display device according to ⁇ 8>.
  • ⁇ 11> A card medium including the image display device according to ⁇ 8>.
  • a display particle dispersion that has a high white display reflectance and suppresses settling of display white particles, and an image display device including the same.
  • an electronic device, an exhibition medium, and a card medium including the image display device can be provided.
  • FIG. 1 is a schematic configuration diagram of an image display apparatus according to an embodiment of the present invention.
  • FIG. 2 is a diagram schematically showing a relationship between an applied voltage and a moving amount (display density) of display colored particles in the image display apparatus according to the embodiment of the present invention. It is explanatory drawing which shows typically the voltage aspect applied between the board
  • the display particle dispersion of the present invention is a display white particle, a display colored particle that moves in response to an electric field, and two or more types of display colored particles excluding white, and a display A dispersion medium for dispersing the colored particles and the white particles for display.
  • the white particles for display are white particles for display containing a white pigment and a resin, and the content of the white pigment (mass of white pigment / (total mass of white pigment and resin)) is 30% by mass or more and 90% by mass or less.
  • the volume average particle size is 100 nm or more and 500 nm or less, and the following formula (1) is satisfied.
  • the white reflectance of the white particles for display is realized.
  • the display white particles satisfy the formula (1), the diffusion due to the Brownian motion of the display white particles and the sedimentation due to its own weight are in an equilibrium state, and apparently become a floating state in the dispersion.
  • the display particle dispersion of the present invention in the display white particles containing the white pigment and the resin, the content of the white pigment and the volume average particle diameter of the display white particles are within the above ranges, By satisfying 1), the reflectance of white display is high and the sedimentation of white particles for display can be suppressed. Further, in the display particle dispersion of the present invention, since the precipitation of the display white particles is suppressed and the dispersion stability is increased, it is considered difficult to prevent the movement of the display colored particles. Also improves.
  • Display colored particles are two or more types of display colored particles that move in response to an electric field, and are display colored particles excluding white.
  • the colored particles for display are, for example, positively or negatively charged, and can move in the dispersion medium by forming an electric field that is equal to or higher than a predetermined electric field strength.
  • the two or more kinds of display colored particles are particles having different colors and different charging characteristics. The difference in the charging characteristics indicates that the charging polarity or the charging amount of the particles is different, or that both the charging polarity and the charging amount are different.
  • the change in display color in the image display device is caused by the movement of the display colored particles in the dispersion medium.
  • composition of display colored particles examples include resin particles, those obtained by fixing a colorant on the surface of the resin particles, and particles containing a colorant in the resin.
  • Other examples of the colored particles for display include insulating metal oxide particles (for example, particles such as glass beads, alumina, and titanium oxide) or metal colloid particles having a plasmon coloring function.
  • Thermoplastic resins used for colored particles for display include, for example, styrenes such as styrene and chlorostyrene; monoolefins such as ethylene, propylene, butylene, and isoprene; vinyl acetate, vinyl propionate, vinyl benzoate, and butyric acid Vinyl esters such as vinyl; ⁇ - such as methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dodecyl methacrylate Methylene aliphatic monocarboxylic acid esters; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl butyl ether; or vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and vinyl isopropenyl
  • thermosetting resin used for the colored particles for display examples include cross-linked copolymers mainly composed of divinylbenzene and cross-linked resins such as cross-linked polymethyl methacrylate, phenol resins, urea resins, melamine resins, polyester resins, and silicones. Examples thereof include resins.
  • Representative resins used for the display colored particles include, for example, polystyrene resins, styrene-alkyl acrylate copolymers, styrene-alkyl methacrylate copolymers, styrene-acrylonitrile copolymers, and styrene-butadiene copolymers.
  • Styrene-maleic anhydride copolymer polyethylene resin, polypropylene resin, polyester resin, polyurethane resin, epoxy resin, silicone resin, polyamide resin, modified rosin, paraffin wax and the like.
  • a resin having a chargeable group (hereinafter referred to as “polymer having a chargeable group”) is preferably used in order to impart charge to the particles.
  • the polymer having a chargeable group is, for example, a polymer having a cationic group or an anionic group.
  • the cationic group as the charging group include an amine group and a quaternary ammonium group (including salts of these groups), and a positively charged polarity is imparted to the particles by the cationic group.
  • examples of the anionic group as the chargeable group include a carboxyl group, a carboxylate group, a sulfonate group, a sulfonate group, a phosphate group, and a phosphate group. Charge polarity is imparted.
  • polymer having a chargeable group examples include, for example, a homopolymer of a monomer having a chargeable group, a monomer having a chargeable group, and another monomer (having no chargeable group). Monomer).
  • Examples of the monomer having a charging group include a monomer having a cationic group (hereinafter referred to as a cationic monomer) and a monomer having an anionic group (hereinafter referred to as an anionic monomer). It is done.
  • Examples of the cationic monomer include the following. Specifically, N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-dibutylaminoethyl (meth) acrylate, N, N-hydroxyethylaminoethyl (meta) ), Acrylate, N-ethylaminoethyl (meth) acrylate, N-octyl-N-ethylaminoethyl (meth) acrylate, N, N-dihexylaminoethyl (meth) acrylate and other aliphatic amino groups (meth) Acrylates: N-methylacrylamide, N-octylacrylamide, N-phenylmethylacrylamide, N-cyclohexylacrylamide, N-phenylacrylamide, Np-methoxy-phenylacrylamide, N, N
  • Preferred examples of the cationic monomer include nitrogen-containing heterocyclic compounds, among which pyrroles such as N-vinylpyrrole; N-vinyl-2-pyrroline, N-vinyl-3-pyrroline, etc. Pyrrolines; N-vinyl pyrrolidine, vinyl pyrrolidine amino ether, pyrrolidines such as N-vinyl-2-pyrrolidone; imidazoles such as N-vinyl-2-methylimidazole; imidazolines such as N-vinyl imidazoline; N- Indoles such as vinyl indole; Indolines such as N-vinylindoline; N-vinylcarbazole, carbazoles such as 3,6-dibromo-N-vinylcarbazole; 2-vinylpyridine, 4-vinylpyridine, 2-methyl- Pyridines such as 5-vinylpyridine; (meth) acrylic piperidine, N-vinylpiperidine Piperidines such as N-vinyl
  • examples of the anionic monomer include a carboxylic acid monomer, a sulfonic acid monomer, and a phosphoric acid monomer.
  • examples of the carboxylic acid monomer include, for example, (meth) acrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, and citraconic acid, and anhydrides thereof, monoalkyl esters thereof, carboxyethyl vinyl ether, or carboxy Examples thereof include vinyl ethers having a carboxyl group such as propyl vinyl ether, and salts thereof.
  • sulfonic acid monomer examples include styrene sulfonic acid, 2-acrylamido-2-methylpropane sulfonic acid, 3-sulfopropyl (meth) click acid ester, bis- (3-sulfopropyl) -itaconic acid ester, and the like.
  • the salt is mentioned.
  • sulfonic acid monomer examples include sulfuric acid monoesters of 2-hydroxyethyl (meth) acrylic acid and salts thereof.
  • Examples of phosphoric acid monomers include vinyl phosphonic acid, vinyl phosphate, acid phosphoxyethyl (meth) acrylate, acid phosphooxypropyl (meth) acrylate, bis (methacryloxyethyl) phosphate, diphenyl-2-methacryloyloxyethyl phosphate Diphenyl-2-acryloyloxyethyl phosphate, dibutyl-2-methacryloyloxyethyl phosphate, dibutyl-2-acryloyloxyethyl phosphate, dioctyl-2- (meth) acryloyloxyethyl phosphate, and the like.
  • Examples of other monomers that may be used in combination with the monomer having a chargeable group include water-soluble monomers (for example, monomers having a hydroxyl group). Specifically, for example, , Hydroxyethyl (meth) acrylate, hydroxybutyl (meth) acrylate, a monomer having an ethylene oxide unit (eg, (oxy) alkyloxyoligoethylene glycol (meth) acrylate such as tetraethylene glycol monomethyl ether (meth) acrylate), or one end of polyethylene glycol (Meth) acrylate), (meth) acrylic acid and salts thereof, maleic acid, (meth) acrylamido-2-methylpropanesulfonic acid and salts thereof, vinylsulfonic acid and salts thereof, and vinylpyrrolidone.
  • Examples of other monomers include other well-known nonionic monomers.
  • (Meth) acryl is a notation for both “acryl” and “methacryl”.
  • (Meth) acrylo is a notation for both “acrylo” and “methacrylo”.
  • (Meth) acrylate is a notation for both “acrylate” and “methacrylate”.
  • colorant used for the colored particles for display examples include organic or inorganic pigments and oil-soluble dyes.
  • examples of the colorant include magnetic powder such as magnetite and ferrite, and carbon black, titanium oxide, magnesium oxide, zinc oxide, phthalocyanine copper-based cyan color material, azo-based yellow color material, azo-based magenta color material, and quinacridone-based material.
  • Known colorants such as a magenta color material, a red color material, a green color material, and a blue color material can be used.
  • colorant examples include aniline blue, calcoyl 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 122C. I. Pigment red 57: 1, C.I. I. Pigment yellow 97, C.I. Blue 15: 1, C.I. I. Pigment Blue 15: 3 is a typical example.
  • the content of the colorant is, for example, from 10% by mass to 99% by mass and preferably from 30% by mass to 99% by mass with respect to the resin that is a component of the colored particles for display.
  • the colored particles for display may contain a charge control agent as necessary.
  • the charge control agent include known ones used for toner materials for electrophotography.
  • cetylpyridyl chloride, BONTRON P-51, BONTRON P-53, BONTRON E-84, BONTRON E-81 above, Quaternary ammonium salts such as Orient Chemical Industry Co., Ltd., salicylic acid metal complexes, phenol condensates, tetraphenyl compounds, metal oxide particles, and metal oxide particles surface-treated with various coupling agents.
  • an external additive may be attached to the surface of the display colored particles.
  • the color of the external additive is preferably transparent so as not to affect the color of the colored particles for display.
  • the external additive include inorganic particles such as metal oxides such as silicon oxide (silica), titanium oxide, and alumina.
  • the external additive may be surface-treated with a coupling agent or silicone oil in order to adjust the charging property, fluidity, environment dependency, etc. of the colored particles for display.
  • coupling agents include positively chargeable coupling agents such as aminosilane coupling agents, aminotitanium coupling agents, and nitrile coupling agents, and no nitrogen atoms (consisting of atoms other than nitrogen).
  • silicone oils include positively charged silicone oils such as amino-modified silicone oils, and dimethyl silicone oils, alkyl-modified silicone oils, ⁇ -methylsulfone modified silicone oils, methylphenyl silicone oils, chlorophenyl silicone oils, and Examples include negatively charged silicone oils such as fluorine-modified silicone oils. These coupling agents or silicone oils are selected according to the desired resistance of the external additive.
  • the primary particle size of the external additive is, for example, preferably from 1 nm to 100 nm, and preferably from 5 nm to 50 nm, but is not limited thereto.
  • the external addition amount of the external additive is, for example, preferably 0.01 parts by mass or more and 3 parts by mass or less, and preferably 0.05 parts by mass or more and 1 part by mass or less with respect to 100 parts by mass of the display colored particles. It is.
  • the external addition amount of the external additive is preferably adjusted based on the balance between the particle diameter of the colored particles for display and the particle diameter of the external additive. When the amount of the external additive is within the above range, at least a part of the external additive is released from the surface of the display colored particles, and this adheres to the surface of the other display colored particles, so that desired charging characteristics are obtained. This is advantageous in that it is easily prevented from being obtained.
  • the external additive may be added to any one of a plurality of types of display coloring particles, or may be externally added to a plurality of types or all types of display coloring particles.
  • the external additive When adding external additives to the surface of all kinds of colored particles for display, the external additive is applied to the surface of the colored particles for display with impact force or the surface of the colored particles for display is heated to display the external additive. It is preferable to firmly adhere to the colored particle surface. Thereby, the external additive is released from the colored particles for display, and the external additive of different polarity is firmly aggregated to prevent formation of an aggregate of the external additive that is difficult to dissociate with an electric field, As a result, it is advantageous in that image quality deterioration is easily prevented.
  • the volume average particle size of the colored particles for display is, for example, preferably from 0.05 ⁇ m to 20 ⁇ m, and preferably from 0.1 ⁇ m to 1 ⁇ m.
  • size of the colored particle for a display does not have a restriction
  • the concentration of the display colored particles in the display particle dispersion is not particularly limited as long as a desired display color can be obtained.
  • the concentration is 0.01% by mass or more and 50% by mass or less. Is good.
  • the concentration of the colored particles for display is preferably within the above range as the concentration in the display particle dispersion in a state of being enclosed between a pair of substrates of the image display device. Further, it is effective to adjust the concentration of the display colored particles by the distance between the pair of substrates of the image display device. In order to obtain a desired hue, the particle concentration decreases as the distance between the pair of substrates of the image display device increases, and the particle concentration increases as the distance decreases.
  • Manufacturing method of colored particles for display Any conventionally known method may be used as a method of manufacturing the colored particles for display. Specifically, the method shown below is mentioned, for example. 1) As described in JP-A-7-325434, the resin, the pigment and, if necessary, the charge control agent are weighed to the desired mixing ratio, the resin is heated and melted, and then the pigment is added and mixed A method of producing colored particles for display after being dispersed and cooled, and then by a pulverizer such as a jet mill, a hammer mill, or a turbo mill.
  • a pulverizer such as a jet mill, a hammer mill, or a turbo mill.
  • a method for producing colored particles for display by polymerization methods such as suspension polymerization, emulsion polymerization, dispersion polymerization, or coacervation, melt dispersion, or emulsion aggregation.
  • the resin has plasticity, the dispersion medium does not boil, and the resin, the colorant, and the dispersion are at a temperature lower than the decomposition point of at least one of the resin, the colorant, and if necessary, the charge control agent.
  • a method of producing particles by dispersing and kneading the medium and, if necessary, the raw material of the charge control agent (specifically, for example, a meteor mixer, a kneader, etc.
  • the above raw materials are put into a suitable container equipped with granular media for dispersion and kneading, for example a heated vibration mill such as an attritor or a heated ball mill, and the container is placed in a preferred temperature range, for example 80 ° C.
  • the granular media for example, steel such as stainless steel and carbon steel, alumina, zirconia, silica and the like are desirably used.
  • the raw material previously fluidized is further dispersed in the container by granular media, and then the dispersion medium is cooled to contain the colorant from the dispersion medium. It is better to precipitate the resin. It is preferable that the granular media generate shear and / or impact while maintaining the motion state during and after cooling, and reduce the particle size of the resulting colored particles for display.
  • the white particles for display satisfy the following formula (1). From the viewpoint of high white display reflectivity and suppression of settling of the white particles for display, the formula (1-2) is preferable. More preferably, the particles satisfy (1-3).
  • k represents the Boltzmann coefficient (J ⁇ K ⁇ 1 )
  • T represents the absolute temperature 298 (K)
  • d represents the volume average particle diameter of the white particles for display ( . ⁇ p showing a nm) is . ⁇ s showing a specific gravity (g / cm 3) of the display white particles exhibit specific gravity of the dispersion medium (g / cm 3) shows the .g is a gravitational acceleration (m / s 2). )
  • the volume average particle diameter of the display white particles and the specific gravity of the display white particles (that is, the white pigment and the resin contained in the particles) are used. This is realized by adjusting the specific gravity of the dispersion medium.
  • the display white particles include a white pigment and a resin.
  • the display white particles have a configuration in which the surface of the pigment is coated with a resin, for example.
  • the resin is not particularly limited, and examples thereof include resins used for display colored particles. However, in order to make the moving speed of the white particles for display sufficiently slow or not to move substantially according to the electric field, it is preferable to use a resin having a reduced chargeable group amount.
  • the white pigment examples include arbitrary white pigments such as zinc oxide, basic lead carbonate, basic lead sulfate, ritbon, zinc sulfide, titanium oxide, zirconia oxide, antimony oxide, and barium sulfate.
  • the white pigment titanium oxide and zirconia oxide are preferable, and titanium oxide is most preferable from the viewpoint of achieving both high reflectance of display white particles and suppression of sedimentation.
  • the titanium oxide particles may be produced by any method such as a sulfuric acid method, a chlorine method, or a gas phase method.
  • the crystal system of titanium oxide may be an anatase type, a rutile type, or a brookite type, but the rutile type is preferred.
  • the titanium oxide particles preferably contain aluminum oxide, aluminum hydroxide, silicon oxide or the like from the viewpoint of suppressing photocatalytic properties.
  • the volume average particle diameter of the white pigment is, for example, preferably from 1 nm to 500 nm, preferably from 10 nm to 200 nm, and more preferably from 20 nm to 150 nm.
  • the volume average particle diameter of the white pigment is in the above range, it is advantageous in that sedimentation is easily suppressed while increasing the white reflectance of the white particles for display.
  • the content of the white pigment in the white particles for display (that is, the mass of the white pigment / (total mass of the white pigment and the resin)) is 30% by mass to 90% by mass, and 40% by mass to 70% by mass. Preferably, 40 mass% or more and 60 mass% or less are more preferable.
  • the white reflectance of the white particles for display can be increased by setting the content of the white pigment to 30% by mass or more, while the white reflectance of the white particles for display is increased by setting the content to 90% by mass or less. However, sedimentation is suppressed.
  • the volume average particle size of the display white particles is from 100 nm to 500 nm, and preferably from 150 nm to 300 nm.
  • the volume average particle size of the white particles for display is 100 nm or more, the white reflectance of the white particles for display can be increased.
  • the volume average particle size is set to 500 nm or less, the white reflectance of the white particles for display is increased. However, sedimentation is suppressed.
  • Specific gravity of the display white particles is preferably from 2.4 g / cm 3 or more 3.6 g / cm 3 or less 2.1 g / cm 3 or more 4.3 g / cm 3, 2.4 g / Cm 3 or more and 3.3 g / cm 3 or less is more preferable. Setting the specific gravity of the display white particles in the above range is advantageous in that the white reflectance of the display white particles is increased and sedimentation is easily suppressed.
  • the white particles for display have a charge characteristic of opposite polarity to that of the colored particles for display, or have a low charge amount and display a moving speed that moves according to electrolysis. Particles that are sufficiently lower than the colored particles for use are preferable, and in particular, particles that do not substantially move in response to an electric field are preferable.
  • the display white particles have a moving speed ratio (that is, the moving speed Vw of the white particles for display / the moving speed Vc of the colored particles for display) that moves according to the electric field with the colored particles for display is 0. .2 or less, preferably 0.1 or less, more preferably 0.05 or less.
  • the moving speed ratio is in the above range, it is advantageous in that a good display contrast due to the colored particles for display is easily realized. Further, it is advantageous in that a decrease in display response due to the movement of the display colored particles being hindered by the movement of the display white particles is easily suppressed.
  • grain is the value measured by the method measured using the cell for a measurement mentioned later.
  • the moving speed ratio of the white particles for display and the colored particles for display moving according to the electric field is the same as the moving speed of the white particles for display and the display for both particles dispersed in the display particle dispersion. It is a ratio with the moving speed of the particles having the slowest moving speed among the colored particles.
  • the concentration of the white particles for display is preferably, for example, 1% by volume to 50% by volume, and preferably Is 2% by volume or more and 30% by volume or less.
  • concentration of the white particles for display is within the above range, the increase in the viscosity of the dispersion medium due to the dispersion of the white particles for display is suppressed while increasing the reflectance of white display, and the decrease in display responsiveness due to the colored particles for display is easily suppressed. This is advantageous.
  • the concentration of the white particles for display is preferably in the above range as the concentration in the display particle dispersion in a state of being enclosed between a pair of substrates of the image display device. It is also effective to adjust the concentration of the display white particles by the distance between the pair of substrates of the image display device. In order to obtain a desired hue, the particle concentration decreases as the distance between the pair of substrates of the image display device increases, and the particle concentration increases as the distance decreases.
  • the display white particles can be produced by a method similar to the method for producing the display colored particles.
  • the dispersion medium is preferably an insulating liquid.
  • “insulating” indicates that the volume resistivity value is 10 11 ⁇ cm or more.
  • Specific examples of the insulating liquid include hexane, cyclohexane, toluene, xylene, decane, hexadecane, kerosene, paraffin, isoparaffin, silicone oil, high-purity petroleum, ethylene glycol, alcohols, ethers, esters, dimethylformamide.
  • silicone oil is preferably used as the dispersion medium.
  • Specific examples of the silicone oil include silicone oils in which a hydrocarbon group is bonded to a siloxane bond (for example, dimethyl silicone oil, diethyl silicone oil, methyl ethyl silicone oil, methyl phenyl silicone oil, diphenyl silicone oil, etc.).
  • dimethyl silicone is particularly preferable.
  • the dispersion medium may contain acids, alkalis, salts, dispersion stabilizers, stabilizers for the purpose of preventing oxidation or ultraviolet absorption, antibacterial agents, preservatives, and the like. Although it is good, it is preferable to add so that it may become the range of the specific volume specific resistance value shown above.
  • anionic surfactants for dispersion media, anionic surfactants, cationic surfactants, amphoteric surfactants, nonionic surfactants, fluorosurfactants, silicone surfactants, metal soaps, alkyl phosphates as charge control agents Esters and succinimides may be added and used.
  • these surfactants include the following.
  • nonionic surfactants include Polyoxyalkylene alkylphenol ethers such as polyoxyethylene nonylphenol ether and polyoxyethylene octylphenyl ether; Polyoxyalkylene ethers such as polyoxyethylene cetyl ether and polyoxypropylene ether; Glycols such as monool type polyoxyalkylene glycol, diol type polyoxyalkylene glycol, triol type polyoxyalkylene glycol; Alkyl alcohol ethers such as primary linear alcohol ethoxylates such as octylphenol ethoxylate and secondary linear alcohol ethoxylates; Polyoxyalkylene alkyl esters such as polyoxyethylene lauryl ester; Sorbitan fatty acid esters such as sorbitan monolaurate, sorbitan dilaurate, sorbitan sesquipalmitate; Polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan dilaurate, polyoxyethylene sorbitan sesquil
  • anionic surfactants include Carboxylates such as polycarboxylic acid type polymer activators and rosin soaps; alcoholic sulfuric acid such as castor oil sulfate ester salt, lauryl alcohol sulfate ester Na salt, lauryl alcohol sulfate ester amine salt, higher alcohol sulfate ester Na salt Ester salts, sulfate amine amine of lauryl alcohol ether, sulfate ester Na salt of lauryl alcohol ether, sulfate ester amine salt of synthetic higher alcohol ether, sulfate ester Na salt of synthetic higher alcohol ether, alkyl polyether sulfate amine salt, Alkyl polyether sulfate sodium salt, natural alcohol EO (ethylene oxide) addition system sulfate amine salt, natural alcohol EO (ethylene oxide) addition system sulfate sodium salt, synthetic alcohol EO Ethylene oxide) addition system sulfate ester amine salt, synthetic alcohol EO
  • amphoteric surfactants examples include various betaine surfactants.
  • the content of these charge control agents in the display particle dispersion is, for example, based on the total solid content of all the particles (that is, the display colored particles and the display white particles). It is good that it is 0.01 mass% or more, Preferably it is 20 mass% or less, More preferably, it is 0.05 mass% or more and 10 mass% or less.
  • the content of the charge control agent is 0.01% by mass or more, it is advantageous in that the desired charge control effect is sufficiently exhibited, and when it is 20% by mass or less, an excessive increase in conductivity of the dispersion medium is achieved. Is advantageous in that it is easily suppressed.
  • the dispersion medium may be added with a polymer.
  • the polymer is preferably a polymer gel or a polymer.
  • the specific gravity of the dispersion medium is, for example, preferably 0.6 g / cm 3 or more and 1.2 g / cm 3 or less, and 0.7 g / cm 3 or more and 1.1 g in an environment at a temperature of 25 ° C. / Cm 3 or less is preferable, and 0.7 g / cm 3 or more and 1.0 g / cm 3 or less is more preferable. Setting the specific gravity of the display white particles in the above range is advantageous in that the precipitation of the display white particles is easily suppressed.
  • the viscosity of the dispersion medium is, for example, preferably from 0.1 mPa ⁇ s to 100 mPa ⁇ s, preferably from 0.1 mPa ⁇ s to 50 mPa ⁇ s in an environment of a temperature of 20 ° C. More preferably, it is s or more and 20 mPa ⁇ s or less. In particular, the viscosity of the dispersion medium is preferably 5 mPa ⁇ s or less.
  • the viscosity of the dispersion medium is 5 mPa ⁇ s or less, the display responsiveness of the colored particles for display is improved, and even when the viscosity is 5 mPa ⁇ s or less, the white particles for display have the above characteristics, so that the sedimentation is suppressed. It is advantageous in that it becomes easy.
  • the viscosity of the dispersion medium can be adjusted, for example, by adjusting the molecular weight, structure, composition, etc. of the dispersion medium.
  • the display dispersion liquid of the present invention may be encapsulated by a capsule wall. That is, the capsule particles may contain display white particles, display colored particles, and a dispersion medium.
  • gelatin As the main material constituting the capsule wall, gelatin, formalin resin and urethane resin can be preferably used, but gelatin is most preferable.
  • Gelatin includes so-called alkali-treated gelatin with treatment with lime in the process of induction from collagen, so-called acid-treated gelatin with treatment with hydrochloric acid, oxygen-treated gelatin with treatment with hydrolase, etc., contained in gelatin molecules
  • treated and modified amino group, imino group, hydroxyl group or carboxyl group as a functional group with a reagent having one group capable of reacting with them, such as phthalated gelatin, succinylated gelatin, trimethrylated gelatin, etc.
  • gelatin derivatives and modified gelatin include those commonly used in the industry described in JP-A-62-215272, page 222, lower left column, line 6 to page 225, upper left column.
  • JP 2005-522313 describes the use of a cross-linking reaction by an enzyme (transglutaminase or the like), and examples thereof include an enzyme that causes such a cross-linking reaction.
  • crosslinking agent examples include epoxy resins, 2-hydroxyalkylamides, tetramethoxymethyl glyceryl, polyaziridine, polycarbodiimide, isocyanates, blocked isocyanates, drying oils (described in JP-T-2009-531532) For example, triglycerides, glycerol epoxy esters, fatty acid triesters, etc.), aliphatic amines, phenols, polyisocyanates, amines, urea, carboxylic acids, alcohols, polyethers, urea formaldehyde, melamines, Examples include aldehydes and salts of polyvalent anions.
  • the crosslinking agent may be used in combination with a catalyst that promotes the crosslinking reaction.
  • a catalyst that promotes the crosslinking reaction.
  • the catalyst include alcohols, phenols, weak acids, amines, metal salts, urethanes described in JP-T-2009-531532. Chelates, organometallic materials, photoinitiators, free radical initiators, onium salts of strong acids.
  • crosslinking agent and / or catalyst thereof is added to the aqueous phase and used, or whether the crosslinking agent and the catalyst are added to the inner phase oil phase to cause the crosslinking reaction in the organic solvent can be appropriately selected.
  • examples of the emulsifying and dispersing apparatus used in the emulsifying and dispersing step for forming the capsule wall include ordinary emulsifying means such as a high-speed stirrer (dissolver), a homogenizer, and an in-line mixer, and in particular, a microreactor or a micromixer. Is preferably used.
  • ordinary emulsifying means such as a high-speed stirrer (dissolver), a homogenizer, and an in-line mixer, and in particular, a microreactor or a micromixer. Is preferably used.
  • the normal emulsification means has a region where shear force necessary for emulsification is limited to the vicinity of the emulsifying blade, so the shearing force becomes uneven near the emulsifying blade, and the particle size distribution of the dispersed droplets There was a problem of widening. Ultrasonic dispersers are used in laboratories or small-scale industrial production scales, but in production systems that demand high productivity, there are issues in controlling production volume, cost, and particle size distribution. Remains.
  • Japanese Patent No. 2630501 discloses an emulsification method using a so-called cylindrical mill as an emulsification method for solving the problem of the particle size distribution caused by using the emulsification means as described above.
  • This emulsification method is an emulsification method in which an inner cylinder is rotated in a fixed outer cylinder, and an emulsion is obtained by passing a mixture of a dispersion medium and a dispersion into a gap between the inner cylinder and the outer cylinder. Is supplied from the side of one end of the outer cylinder from the tangential direction along the circumference so that a uniform shear force is applied over the length of the inner cylinder while the mixture moves while rotating through the gap between the inner and outer cylinders.
  • an emulsified liquid having an extremely narrow particle size distribution can be obtained, but the size of the droplet particle size obtained by this method depends on the size of the gap between the inner cylinder and the outer cylinder. It is difficult to obtain emulsified particles having a particle size below a certain limit, and the particle size of droplets obtained by this method is usually about 10 ⁇ m, and it is difficult to obtain droplets with a particle size of several ⁇ m or less. It is.
  • microreactors have been used in the fields of fine chemicals, biochemicals, etc., and have recently been greatly developed (W. Ehrfeld, V. Hessel, H. Lowe, " Microreactor”, 1Ed. (2000), WILEY-VCH).
  • a microreactor is a general term for reaction devices having a plurality of microscale flow paths (channels). For example, two types of liquids contact each other as extremely thin liquid films while passing through different flow paths. In the meantime, mass transfer takes place through the interface of the layers and a reaction takes place.
  • the microreactor is used not only for a chemical reaction but also for mixing or separating two or more liquids.
  • a microreactor used for mixing is called a micromixer, which forms liquid films of different liquids to be mixed in a laminated structure, and mixes them by passing through narrow passages.
  • An emulsified dispersion can be prepared by using an oil phase liquid and an aqueous phase liquid.
  • WO 00/62913 proposes a disperser (micromixer) that performs dispersion using such a microreactor. This disperser is divided into spatially divided liquid layers (liquid films) by separately passing the liquid flows of liquid A and liquid B through micro-scale flow paths (channels), and then divided. In this method, the liquid A or the liquid B is dispersed into fine droplets by combining the liquid flow and passing through a narrow passage, and at that time, droplet formation is promoted using a mechanical oscillator.
  • Image display device The image display device according to the present embodiment has a pair of substrates, at least one of which has translucency, a display particle dispersion encapsulated between the pair of substrates, and a strength for moving the display colored particles.
  • Electric field generating means for applying an electric field between the pair of substrates.
  • the display particle dispersion according to the embodiment of the present invention is applied as the display particle dispersion.
  • FIG. 1 is a schematic configuration diagram illustrating an image display apparatus according to an embodiment of the present invention.
  • the image display device 10 according to an embodiment of the present invention uses the display medium according to the present embodiment as a particle dispersion liquid including the colored particle group 34, the white particle group 36, and the dispersion medium 50 of the display medium 12.
  • a particle dispersion is applied.
  • a group of display colored particles is applied as the colored particle group 34
  • display white particles are applied as the white particle group 36.
  • the image display apparatus 10 includes a display medium 12, a voltage application unit 16 (an example of an electric field generating unit), and a control unit 18, as shown in FIG.
  • the display medium 12 holds a display substrate 20 as a display surface, a back substrate 22 facing the display substrate 20 with a gap, and a gap between these substrates at a predetermined interval. And a gap member 24 that partitions the substrate 20 and the back substrate 22 into a plurality of cells.
  • the cell refers to a region surrounded by the display substrate 20, the back substrate 22, and the gap member 24.
  • a colored particle group 34, a white particle group 36, and a dispersion medium 50 for dispersing these particle groups are enclosed.
  • the colored particle group 34 and the white particle group 36 are dispersed in the dispersion medium 50, and the colored particle group 34 moves between the display substrate 20 and the back substrate 22 in accordance with the electric field strength formed in the cell.
  • a surface layer 25 is provided on the inner surface of each gap member 24.
  • the gap member 24 is provided so as to correspond to each pixel when an image is displayed on the display medium 12, and cells are formed so as to correspond to each pixel, whereby the display medium 12 displays the color for each pixel. May be configured to be possible.
  • a plurality of types of colored particle groups 34 having different colors are dispersed in the dispersion medium 50 of the display medium 12.
  • the plurality of types of colored particle groups 34 are particles that can be electrophoresed between the substrates, and the absolute value of the voltage required to move in accordance with the electric field is different for each color particle group.
  • the display substrate 20 has a configuration in which a surface electrode 40 and a surface layer 42 are sequentially laminated on a support substrate 38.
  • the back substrate 22 has a structure in which a back electrode 46 and a surface layer 48 are sequentially laminated on a support substrate 44.
  • Examples of the material of the support substrate 38 and the support substrate 44 include glass and plastic, for example, polycarbonate resin, acrylic resin, polyimide resin, polyester resin, epoxy resin, polyether sulfone resin, and the like.
  • Examples of materials for the front electrode 40 and the back electrode 46 include oxides such as indium, tin, cadmium and antimony, composite oxides such as ITO, metals such as gold, silver, copper and nickel, organics such as polypyrrole and polythiophene. Materials and the like.
  • the front electrode 40 and the back electrode 46 may be any of these single layer films, mixed films, or composite films, and are formed by, for example, vapor deposition, sputtering, coating, or the like.
  • the film thicknesses of the surface electrode 40 and the back electrode 46 are adjusted as appropriate so as to obtain a desired conductivity, but are generally 10 nm or more and 1 ⁇ m or less.
  • the back electrode 46 and the front electrode 40 are formed in a desired pattern, for example, a matrix shape or a stripe shape that enables passive matrix driving, by a conventionally known means such as etching of a conventional liquid crystal display element or a printed board.
  • the surface electrode 40 may be embedded in the support substrate 38.
  • the back electrode 46 may be embedded in the support substrate 44.
  • the back electrode 46 and the surface electrode 40 may be separated from the display substrate 20 and the back substrate 22 and disposed outside the display medium 12.
  • the support substrate 38 and the support substrate 44 are provided with active elements such as TFT (Thin Film Transistor), TFD (Thin Film Diode), MIM (Metal-Insulator-Metal) element, and varistor for each pixel. May be provided.
  • the active elements are preferably formed not on the display substrate 20 but on the back substrate 22 because wiring can be easily stacked and components can be easily mounted.
  • the surface electrode 40 and the back electrode 46 are formed on the support substrate 38 and the support substrate 44, respectively, the electrodes between the electrodes that cause the damage of the surface electrode 40 and the back electrode 46 and the fixation of the particles of the colored particle group 34 are formed.
  • the surface layer 42 and the surface layer 48 as dielectric films on the surface electrode 40 and the back electrode 46, respectively, as necessary.
  • the surface layers each of the surface layer 42 and the surface layer 48
  • the display substrate 20 and the back substrate 22 are described. The structure provided only in either one of these opposing surfaces may be sufficient. These surface layers may be made of different materials.
  • Examples of the material of the surface layer 42 and the surface layer 48 include polyolefins such as polyethylene and polypropylene, polycarbonate, polyester, polystyrene, polyimide, polyurethane, polyamide, polymethyl methacrylate, copolymer nylon, epoxy resin, ultraviolet curable acrylic resin, A silicone resin, a fluororesin, etc. are mentioned.
  • polyolefins such as polyethylene and polypropylene, polycarbonate, polyester, polystyrene, polyimide, polyurethane, polyamide, polymethyl methacrylate, copolymer nylon, epoxy resin, ultraviolet curable acrylic resin, A silicone resin, a fluororesin, etc. are mentioned.
  • the dispersion medium 50 is a silicone oil
  • the high molecular compound which has a silicone chain is mentioned suitably from a viewpoint of adhesion prevention of particle
  • the polymer compound having a silicone chain for example, a copolymer containing the following structural unit (A) and the following structural unit (B) can be applied.
  • X represents a group containing a silicone chain.
  • Ra 1 represents a hydrogen atom or a methyl group.
  • Ra 2 represents a hydrogen atom, a methyl group, or a halogen atom (for example, a chlorine atom).
  • Rb 2 represents a hydrogen atom, an alkyl group, an alkenyl group, a cyano group, an aromatic group, a heterocyclic group, or —C ( ⁇ O) —O—Rc 2 (where Rc 2 represents an alkyl group, a hydroxyalkyl group, Represents a polyoxyalkyl group (-(C x H 2x -O) n -H [x, n is an integer of 1 or more]), an amino group, a monoalkylamino group, or a dialkylamino group.) n1 and n2 represent mol% of each structural unit with respect to the entire copolymer, and represent 0 ⁇ n1 ⁇ 50 and 0 ⁇ n2 ⁇ 80. n represents a natural number of 1 or more and 3 or less.
  • the group containing a silicone chain represented by X is, for example, a group containing a linear or branched silicone chain (a siloxane chain in which two or more Si—O bonds are linked), Preferably, it includes a dimethylsiloxane chain in which two or more dimethylsiloxane structures (—Si (CH 3 ) 2 —O—) are connected, and a part thereof (part of —CH 3 ) may be substituted. It is a group.
  • Specific examples of the group containing a silicone chain represented by X include a group represented by the following structural formula (X1) or (X2).
  • R 1 represents a hydroxyl group, a hydrogen atom, or an alkyl group having 1 to 10 carbon atoms.
  • n represents an integer of 1 to 10.
  • a dimethyl silicone monomer having a (meth) acrylate group at one end for example, Silasplain FM manufactured by Chisso Corporation
  • a dimethyl silicone monomer having a (meth) acrylate group at one end for example, Silasplain FM manufactured by Chisso Corporation
  • -0711, FM-0721, FM-0725, etc. all trade names
  • Silaplane FM-0711, FM-0721, FM-0725, etc. are preferable.
  • Examples of the monomer of the structural unit (B) include (meth) acrylonitrile, (meth) acrylic acid alkyl esters such as methyl methacrylate and butyl methacrylate, (meth) acrylamide, ethylene, propylene, butadiene, isoprene, and isobutylene.
  • the polymer compound having a silicone chain may contain a crosslinking unit in addition to the structural units (A) and (B).
  • a crosslinking unit for example, a monomer containing an epoxy group, an oxazoline group, an isocyanate group, or the like can be used.
  • the weight average molecular weight of the polymer compound having a silicone chain is preferably from 100 to 1,000,000, more preferably from 400 to 1,000,000.
  • the weight average molecular weight is measured by a static light scattering method or size exclusion column chromatography, and the numerical values described in this specification are measured by the method.
  • the thickness of the surface layer (surface layer 42 or surface layer 48) containing a polymer compound having a silicone chain is, for example, 0.001 ⁇ m or more and 10 ⁇ m or less, and preferably 0.01 ⁇ m or more and 1 ⁇ m or less.
  • an insulating material containing a charge transporting substance may be used.
  • Inclusion of a charge transport material improves particle chargeability by injecting particles into the particle, and when the charge amount of the particle becomes extremely large, the charge of the particle is leaked and the charge amount of the particle is stabilized. An effect is obtained.
  • Examples of charge transport materials include hole transport materials such as hydrazone compounds, stilbene compounds, pyrazoline compounds, and arylamine compounds, electron transport materials such as fluorenone compounds, diphenoquinone derivatives, pyran compounds, and zinc oxide, and polyvinylcarbazole. Examples thereof include resins having charge transport properties such as
  • the gap member 24 is a member for holding a gap between the display substrate 20 and the back substrate 22 and is formed so as not to impair the transparency of the display substrate 20, and is made of a thermoplastic resin, a thermosetting resin, an electronic device. It is formed of a line curable resin, a photo curable resin, rubber, metal, or the like.
  • a surface layer 25 is provided on the inner surface of the gap member 24. The material and thickness of the surface layer 25 are the same as those of the surface layers 42 and 48 described above.
  • the gap member 24 includes a cell type and a particle type. Examples of the cellular shape include a net or a sheet having holes formed in a matrix shape by etching or laser processing.
  • the gap member 24 may be integrated with either the display substrate 20 or the back substrate 22, and the support substrate 38 or the support substrate 44 is etched or laser processed, or a prefabricated mold is used and pressed.
  • the support substrate 38 or the support substrate 44 having a cell pattern of any size and the gap member 24 are manufactured by processing or printing.
  • the gap member 24 can be fabricated on either the display substrate 20 side, the back substrate 22 side, or both.
  • the gap member 24 may be colored, but is preferably colorless and transparent so as not to adversely affect the display image displayed on the display medium 12.
  • the voltage application unit 16 is electrically connected to the front electrode 40 and the back electrode 46. In this embodiment, the case where both the front electrode 40 and the back electrode 46 are electrically connected to the voltage application unit 16 will be described. However, one of the front electrode 40 and the back electrode 46 is grounded. The other may be connected to the voltage application unit 16.
  • the voltage application unit 16 is a voltage application device (for example, a power supply) for applying a voltage to the surface electrode 40 and the back electrode 46, and applies a voltage between the surface electrode 40 and the back electrode 46 according to the control of the control unit 18. To do.
  • the control unit 18 is connected to the voltage application unit 16 so as to be able to exchange signals.
  • the control unit 18 includes a CPU (Central Processing Unit) that controls the operation of the entire apparatus, a RAM (Random Access Memory) that temporarily stores various data, and a control program and processing routine that control the entire apparatus.
  • a microcomputer including a ROM (Read Only Memory) in which various programs including the program shown are stored in advance.
  • the display medium 12 displays different colors by changing the applied voltage (V) applied between the display substrate 20 and the back substrate 22.
  • V applied voltage
  • the colored particles move in accordance with the electric field formed between the display substrate 20 and the back substrate 22, so that each pixel corresponding to each pixel of the display medium 12 is assigned to each pixel of the image data. A corresponding color can be displayed.
  • the colored particle group 34 moves for each color according to the electric field when electrophoresis is performed between the substrates. Therefore, the absolute value of the voltage required for each is different.
  • the colored particle group 34 for each color has a voltage range necessary for moving the colored particle group 34 for each color, and the voltage range is different. In other words, the absolute value of the voltage has the voltage range, and the voltage range is different for each color of the colored particle group 34.
  • the magenta magenta particle group 34M, the cyan cyan particle group 34C, and the yellow color yellow particle group 34Y are used as absolute values of voltages when the three color particle groups start moving. It is assumed that 34M is
  • Absolute value of a value between Vtc and Vdc
  • absolute value of a value between Vtm and Vdm
  • yellow The absolute value of the voltage range necessary to move the particle group 34M
  • of the maximum voltage for moving almost all of the cyan particle groups 34M is within the voltage range necessary for moving the magenta particle group 34M.
  • (Vty to Vdy) Is set to be smaller than the absolute value).
  • of the maximum voltage for moving almost all of the magenta particle group 34M is equal to the absolute value
  • the color particle groups 34 of each color are driven independently by setting the voltage ranges necessary for moving the color particle groups 34 of each color so as not to overlap.
  • the “voltage range necessary for moving the colored particle group 34” means the voltage necessary for the particle to start moving and the change in display density even if the voltage and voltage application time are further increased from the start of movement. Indicates a voltage range until the display density is saturated.
  • the “maximum voltage necessary for moving almost all the colored particle groups 34” means that even if the voltage and voltage application time are further increased from the start of the above movement, the display density does not change and the display density is saturated. Indicates the voltage to be used.
  • “almost all” means that there are variations in the characteristics of some of the colored particle groups 34 of each color, so that some of the characteristics of the colored particle groups 34 do not contribute to the display characteristics. That is, even if the voltage and the voltage application time are further increased from the start of the movement described above, the display density does not change and the display density is saturated.
  • the voltage applied between the substrates is gradually increased by applying a voltage from 0 V between the front substrate 20 and the rear substrate 22 to increase the voltage value of the applied voltage.
  • the display density starts to change due to the movement of the cyan particle group 34C in the display medium 12. Further, when the voltage value is increased and the voltage applied between the substrates becomes + Vdc, the change in display density due to the movement of the cyan particle group 34 in the display medium 12 stops.
  • the display medium 12 displays magenta.
  • a change in display density due to the movement of the particle group 34M begins to appear.
  • the absolute value of the voltage value is further increased and the voltage applied between the front substrate 20 and the rear substrate 22 becomes ⁇ Vdm, the change in display density due to the movement of the magenta particle group 34M in the display medium 12 stops. .
  • the display medium 12 displays yellow. Changes in the display density begin to appear due to the movement of the particle group 34Y.
  • the absolute value of the voltage value is further increased and the voltage applied between the substrates becomes ⁇ Vdy, the change in display density due to the movement of the yellow particle group 34C in the display medium 12 stops.
  • the voltages applied between the substrates are within the range of ⁇ Vtc to Vtc (voltage range
  • a voltage equal to or higher than the absolute values of the voltage + Vtc and the voltage ⁇ Vtc is applied between the substrates, a change occurs in the display density of the display medium 12 for the cyan particle group 34C among the three color particle groups 34.
  • the display density starts to change only when a certain amount of particle movement starts to occur, and when a voltage higher than the voltage ⁇ Vdc and the absolute value
  • the display when a voltage is applied between the front substrate 20 and the rear substrate 22 so that the voltage applied between the substrates is within the range of ⁇ Vty to Vty (voltage range
  • the yellow particle group 34Y starts to move and display a particle that causes a change in the display density of the display medium 12.
  • the density starts to change and a voltage equal to or higher than the absolute value
  • a voltage ⁇ Vdy is applied between the display substrate 20 and the rear substrate 22. Thereby, all of the magenta particle group 34M, the cyan particle group 34C, and the yellow particle group 34Y are positioned on the back substrate 22 side (see FIG. 3A).
  • the yellow particle group 34Y having the highest movement start voltage is moved or left as it is.
  • the voltage + Vdy is applied, all of the magenta particle group 34M, the cyan particle group 34C, and the yellow particle group 34Y move to the display substrate 20 side and display black (K) (see FIG. 3B).
  • the voltage + Vty is applied, the magenta particle group 34M and the cyan particle group 34C move to the display substrate 20 side, but the yellow particle group 34Y remains as it is and remains on the back substrate 22 side as blue (B). Display is made (see FIG. 3C).
  • the voltage is greater than or equal to + Vty and less than or equal to + Vdy, a part of the yellow particle group 34Y moves, so that a halftone can be obtained.
  • magenta particle group 34M having the second highest movement start voltage is moved or left as it is.
  • the voltage ⁇ Vdm is applied, the magenta particle group 34M moves to the back substrate 22 side.
  • the voltage ⁇ Vtm is applied, the magenta particle group 34M remains on the display substrate 20 side.
  • the cyan particles 34C whose movement start voltage is lower than the magenta particles 34M move to the back substrate 22 side in any case.
  • the yellow particles 34Y whose movement start voltage is higher than the magenta particles 34M maintain the previous state (for example, the state of FIG. 3A or the state of FIG. 3B) in any case.
  • the voltage is ⁇ Vtm or more and ⁇ Vdm or less, a part of the magenta particle group 34M moves, so that a halftone can be obtained.
  • the cyan particle 34C having the lowest movement start voltage is moved or left as it is.
  • the cyan particle group 34C moves to the display substrate 20 side.
  • the voltage + Vtc is applied, the cyan particle group 34C remains on the back substrate 22 side.
  • the magenta particles 34M and the yellow particles 34Y whose movement start voltage is higher than that of the cyan particle group 34C maintain the previous state in any case. Therefore, when the voltage + Vtc is applied, the previous display color is maintained.
  • the voltage is greater than or equal to + Vtc and less than or equal to + Vdc, part of the cyan particle group 34C moves, so that a halftone can be obtained.
  • any color display can be performed by selectively moving desired particles by applying a voltage corresponding to the particle group between the substrates in order from each colored particle group 34 having a high movement start voltage. It becomes.
  • the image display device of the present invention is provided in an electronic device, an exhibition medium, a card medium, and the like.
  • the image display device of the present invention includes, for example, an electronic bulletin board capable of storing and rewriting images, an electronic circulation version, an electronic blackboard, an electronic advertisement, an electronic signboard, a flashing sign, electronic paper, an electronic newspaper, and an electronic book.
  • Electronic document sheets that can be shared with copiers and printers, portable computers, tablet computers, mobile phones, smart cards, signature devices, watches, shelf labels, flash drives, etc.
  • volume average particle size of the particles was measured using a Coulter Multisizer-type II (trade name; manufactured by Beckman-Coulter) with an aperture diameter of 50 ⁇ m. At this time, the measurement is performed after the particles are dispersed in an electrolyte aqueous solution (Isoton aqueous solution, manufactured by Beckman Coulter, Inc.) and dispersed by ultrasonic waves for 30 seconds or more.
  • Coulter Multisizer-type II trade name; manufactured by Beckman-Coulter
  • a measurement method 0.5 mg to 50 mg of a measurement sample is added to 2 ml of a 5% aqueous solution of a surfactant (sodium alkylbenzene sulfonate) as a dispersant, and this is added to 100 ml to 150 ml of an electrolytic solution.
  • the electrolytic solution in which the measurement sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 minute, and the particle size distribution of the particles is measured.
  • the number of particles to be measured is 50,000.
  • a cumulative distribution is drawn from the smaller diameter side with respect to the divided particle size range (channel), and the particle size at which 50% is accumulated is defined as the volume average particle size.
  • the specific gravity of the particles was calculated from the content of the pigment contained therein, the specific gravity of the pigment, and the specific gravity of the resin.
  • the specific gravity of the pigment and the resin was measured according to a known solid density and specific gravity measurement method (for example, JIS Z8807).
  • the specific gravity of the dispersion medium was measured in accordance with a known method for measuring density and specific gravity of liquid (for example, JIS Z8804).
  • the glass transition temperature is based on JIS K7121-1987 (corresponding to ISO 3146-1985) using a differential scanning calorimeter (DSC-50 manufactured by Shimadzu Corporation; trade name). And measured. The melting point of a mixture of indium and zinc was used for temperature correction of the detection part of this apparatus, and the heat of fusion of indium was used for correction of heat quantity.
  • the particles were put in an aluminum pan as they were, and an aluminum pan containing particles and an empty aluminum pan for control were set, and measurement was performed at a heating rate of 10 ° C./min.
  • the glass transition temperature was defined as the temperature at the intersection of the extension line of the base line and the rising line in the endothermic part of the DSC curve obtained by the measurement.
  • Example 1 Production of CRW Mixed Cyan Particles C1 1) Production of Core Particles Preparation of Dispersed Phase The following components were mixed while heating to 60 ° C., the ink solid content concentration was 15%, and the pigment concentration after drying was 50 The disperse phase was prepared to be%.
  • Styrene acrylic polymer X345 (trade name; manufactured by Seiko PMC): 7.2 g -Cyan pigment PB15: 3 aqueous dispersion: 18.8 g (Emacol SF Blue H524F (trade name; manufactured by Sanyo Dye Co., Ltd., solid content: 26% by mass)) ⁇ Distilled water: 24.1 g
  • Particle preparation 50 g of the above dispersed phase and 350 g of the above continuous phase are mixed, and emulsified for 10 minutes at a rotational speed of 10,000 rpm and a temperature of 30 ° C. using an internal tooth tabletop dispersing machine ROBOMICS (trade name; manufactured by Tokushu Kika Kogyo Co., Ltd.) Went.
  • ROBOMICS trade name; manufactured by Tokushu Kika Kogyo Co., Ltd.
  • the obtained particle suspension was centrifuged at 6,000 rpm for 15 minutes, the supernatant was removed, and the washing step of redispersing with silicone oil KF-96-2CS was repeated three times. In this way, 6 g of core particles were obtained. As a result of SEM image analysis, the average particle size was 0.6 ⁇ m.
  • the product was purified and dried using cyclohexane as a reprecipitation solvent to obtain a shell resin. 2 g of this shell resin was dissolved in 20 g of t-butanol solvent to prepare a shell resin solution.
  • Particle coating with shell resin 1 g of the above core particles was placed in a 200 mL eggplant flask, 15 g of silicone oil KF-96-2cs was added, and the mixture was stirred and dispersed while applying ultrasonic waves. To this, 7.5 g of t-butanol, 22 g of the above shell resin solution, and 12.5 g of silicone oil KF-96-2cs (trade name; manufactured by Shin-Etsu Chemical Co., Ltd.) were sequentially added. The input speed was all 2 mL / s.
  • the eggplant flask was connected to a rotary evaporator, and t-butanol was removed at a vacuum of 20 mbar and a water bath temperature of 50 ° C. for 1 hour.
  • Dispersion A-1B The following components were mixed, and finely pulverized with a ball mill in the same manner as described above to obtain a calcium carbonate dispersion A- 1B was prepared. ⁇ Calcium carbonate: 40g ⁇ Water: 60g
  • Quaternary ammoniumation treatment The obtained particles were dispersed in silicone oil KF96-1cs (manufactured by Shin-Etsu Chemical Co., Ltd.), and dodecyl bromide (quaternizing agent) was used to prepare particles 2- (diethylamino) methacrylate. An equimolar amount with ethyl was added, and the mixture was heated at 90 ° C. for 6 hours. After cooling, this dispersion was washed with a large amount of silicone oil and dried under reduced pressure to obtain red particles R1. The glass transition temperature of the resin contained in the particles was 145 ° C.
  • Preparation of white particles W1 1) Preparation of core particle solution A1 (continuous phase) The following materials were mixed and a polymer dispersant E1 was synthesized by radical solution polymerization (at 55 ° C. for 6 hours).
  • Methacrylic acid manufactured by Aldrich
  • Silicone oil KF-96-2cs manufactured by Shin-Etsu Chemical Co., Ltd.
  • 40g ⁇ Polymerization initiator V-65 (manufactured by Wako Pure Chemical Industries): 0.06 g
  • the product was diluted with silicone oil KF-96-2cs (manufactured by Shin-Etsu Chemical Co., Ltd.) so that the amount of the polymerization anti-soluble component was 3 g, and a solution A1 (continuous phase) containing the polymer dispersant E1
  • solution B1 (dispersed phase) A mixture of 10 g of styrene acrylic resin X-1202L (trade name; manufactured by Seiko PMC), 10 g of titanium dioxide TTO-55A (trade name; manufactured by Ishihara Sangyo Co., Ltd.), and 90 g of distilled water Zirconia beads were added to the mixture, and dispersion treatment was performed for 1 hour with a rocking mill to obtain dispersed phase B1.
  • the obtained emulsion is put into an eggplant flask, water is removed by heating and reducing to 65 ° C. and 10 mPa with an evaporator while stirring, and a particle dispersion in which titanium dioxide particles are dispersed in silicone oil is obtained. Obtained.
  • the obtained dispersion was sedimented using centrifugation, the supernatant was removed, and toluene was added to prepare a particle solid concentration of 20% by mass to obtain a particle toluene dispersion C1.
  • Shell resin 10g -Particle toluene dispersion C1 (particle solid content concentration 20% by mass): 50 g
  • Each material was mixed with the above composition, and 200 g of silicone oil KF-96L-2cs (manufactured by Shin-Etsu Chemical Co., Ltd.) was added dropwise to deposit a shell resin.
  • the dispersion liquid of the white particle W1 which consists of a titanium oxide coat
  • the volume average particle diameter of the white particles W1 was 250 nm.
  • the titanium oxide content (pigment content) of the white particles W1 was 40% by mass.
  • the resulting particle suspension is centrifuged at 8,000 rpm for 10 minutes, the supernatant is removed, and the washing process is performed three times by re-dispersing with silicone oil KF-96-2cs (manufactured by Shin-Etsu Chemical Co., Ltd.). Repeated. Finally, the particle solid content concentration was adjusted to 40% by mass with silicone oil to obtain a dispersion of white particles W13.
  • the volume average particle diameter of the white particles W9 was 398 nm.
  • Display Particle Dispersions 1 to 13 (CRW Mixed Particle Dispersion) Cyan particles C1, red particles R1, and white particles W1 are solid particles of cyan particles C1 of 0.1 g, red particles R1 of 1.3 g, Weigh and mix so that white particle W1 is 2.0 g, add silicone oil KF-96L-2cs (manufactured by Shin-Etsu Chemical Co., Ltd.) so that the liquid volume is 10 g, and ultrasonically stir to display particles. Dispersion 1 was prepared. Similarly, display particle dispersions 2 to 13 were prepared using white particles W2 to W13 in place of the white particles W1, respectively. The viscosity of “silicone oil KF-96L-2cs (manufactured by Shin-Etsu Chemical Co., Ltd.)” corresponding to the dispersion medium was 2 mPa ⁇ s.
  • the resulting product was purified using hexane as a reprecipitation solvent and dried to obtain polymer compound A.
  • the polymer compound A was dissolved in IPA (isopropyl alcohol) so that the solid content concentration was 4 wt%.
  • a solution of the polymer compound A is spin-coated on a glass substrate on which ITO (indium tin oxide) having a thickness of 50 nm is formed as an electrode by a sputtering method, and dried at 130 ° C. for 1 hour. A surface layer was formed.
  • Two ITO substrates with a surface layer thus prepared were prepared and used as a display substrate and a back substrate.
  • a Teflon (registered trademark) sheet having a thickness of 50 ⁇ m as a spacer the display substrate was superimposed on the back substrate with the surface layers facing each other, and fixed with clips.
  • An evaluation cell 1 was produced by injecting the display particle dispersion 1 into the empty cell for evaluation thus produced.
  • evaluation cells 2 to 13 were produced using the display particle dispersions 2 to 13 instead of the display particle dispersion 1, respectively.
  • the evaluation cells are listed below in Table 1.
  • Table 1 the calculation of the “6 kT / ( ⁇ d 3 ( ⁇ p ⁇ s) g)” value of the general formula (1) is based on the volume average particle diameter of the white particles applied to each evaluation cell, the specific gravity of the white particles, And the specific gravity of silicone oil as a dispersion medium.
  • the specific gravity of the white particles, titanium oxide content, specific gravity of 4.26 g / cm 3 of titanium oxide was calculated from the specific gravity of 1.2 g / cm 3 of resin.
  • the specific gravity of silicone oil was calculated as 0.878 g / cm 3 .
  • the dispersed positively charged cyan particles and positively charged red particles moved to the negative electrode, that is, the surface electrode side, and when observed from the display substrate side, black was observed.
  • the reflection density at this time was measured with a spectrocolorimeter (X-Rite 939 manufactured by X-Rite Co., Ltd.) to obtain Dmax.
  • X-Rite 939 manufactured by X-Rite Co., Ltd.
  • Example 2 Preparation of YMCW mixed system yellow particles Y1
  • Preparation of dispersion A-1A The following components were mixed and ball milling was performed for 20 hours with zirconia balls having a diameter of 10 mm to prepare dispersion A-1A.
  • Dispersion A-1B The following components were mixed and finely pulverized with a ball mill in the same manner as described above to prepare a calcium carbonate dispersion A-1B.
  • the particles were filtered, and the obtained particle powder was dispersed in ion-exchanged water, and calcium carbonate was decomposed with hydrochloric acid water, followed by filtration. After washing with sufficient distilled water, the openings were passed through nylon sieves having a mesh size of 15 ⁇ m and 10 ⁇ m to make the particle sizes uniform. The obtained particles had a volume average particle size of 13 ⁇ m.
  • Quaternary ammoniumation treatment The obtained particles were dispersed in silicone oil KF96-1cs (manufactured by Shin-Etsu Chemical Co., Ltd.), and dodecyl bromide (quaternizing agent) was used to prepare particles 2- (diethylamino) methacrylate. An equimolar amount with ethyl was added, and the mixture was heated at 90 ° C. for 6 hours. After cooling, this dispersion was washed with a large amount of silicone oil and dried under reduced pressure to obtain yellow particles Y1. The glass transition temperature of the resin contained in the particles was 145 ° C.
  • Preparation of magenta particles M1 1) Preparation of core particles Preparation of dispersed phase The following components were mixed while heating to 60 ° C., and the dispersed phase was adjusted so that the ink solid content concentration was 15% and the pigment concentration after drying was 50%.
  • Styrene acrylic polymer X345 (trade name, manufactured by Seiko PMC): 7.2 g -Aqueous dispersion of magenta pigment PR122, Emacol SF Blue H502F (trade name, manufactured by Sanyo Color Co., Ltd., solid content: 21% by mass): 20 g ⁇ Distilled water: 22.8 g
  • Particle Preparation 50 g of the above dispersed phase and 350 g of the above continuous phase are mixed, and emulsified for 10 minutes at a rotational speed of 10,000 rpm and a temperature of 30 ° C. using an internal tooth tabletop dispersing machine ROBOMICS (trade name, manufactured by Tokushu Kika Kogyo Co., Ltd.). Went.
  • ROBOMICS trade name, manufactured by Tokushu Kika Kogyo Co., Ltd.
  • the obtained particle suspension was centrifuged at 6,000 rpm for 15 minutes, the supernatant was removed, and the washing step of redispersing with silicone oil KF-96-2CS was repeated three times. In this way, 6 g of core particles were obtained. As a result of SEM image analysis, the average particle size of the core particles was 0.6 ⁇ m.
  • the cyan particles C1, the magenta particles M1, the yellow particles Y1, and the white particles W1 are solid particles of cyan particles C1 of 0.1 g, magenta particles M1 of 0.1 g, yellow particles Y1 of 1.3 g, and white particles W1 of 2 Weigh and mix to 0.0 g, add silicone oil KF-96L-2cs (manufactured by Shin-Etsu Chemical Co., Ltd.) to a liquid volume of 10 g, and ultrasonically stir to give display particle dispersion 2-1 Prepared.
  • display particle dispersions 2-2 to 2-13 were prepared using white particles W2 to W9 instead of the white particles W1, respectively.
  • Evaluation cells were produced in the same manner as in the evaluation cell 1 (Example 1) except that the display particle dispersions 1-2 to 2-13 were used. And about each obtained evaluation cell, when the white display reflectance and response time were evaluated similarly to Example 1, it has confirmed that the same result was obtained.
  • Example 3 In the white particles W1, according to Table 3, the amount of monomer species was changed to synthesize a shell resin. Except for using this shell resin, white particles W14 to W17 were obtained in the same manner as the white particles W1. Further, display particle dispersions 14 to 17 were obtained. Evaluation cells 14 to 17 were prepared in the same manner as in the evaluation cell 1 (1) except that the display particle dispersions 14 to 17 were used, and the same evaluation as in Example 1 was performed. In the white particles W14 to W17 and the display particle dispersions 14 to 17, the titanium oxide content, the value of “6 kT / ( ⁇ d 3 ( ⁇ p ⁇ s) g)” in the general formula (1), The same as the display particle dispersion 1.
  • An empty cell for measuring speed was prepared by forming two counter electrodes horizontally facing each other at a distance of 300 ⁇ m on a glass substrate, and each of them was filled with display particle dispersions 10-13, A cell for speed measurement was produced. Then, a potential difference of 0.3 V / ⁇ m was applied between the counter electrode of the velocity measuring cell to move the particles, and the situation was photographed using an optical microscope with a high-speed camera. The time required for the particle group to move between the counter electrode was measured, and the moving speed was calculated. Specifically, with the particles to be measured moved to one of the counter electrodes, a potential difference is applied between the counter electrodes, and more than half of the particles move to the other of the counter electrodes at the center between the counter electrodes.
  • the time required for the measurement was measured, and the moving speed of the particles was calculated from the time and the distance between the counter electrodes (300 ⁇ m).
  • the measurement object is cyan particles having a slow moving speed among white particles and colored particles.
  • the moving speed of cyan particles (Vc: ⁇ m / sec), the moving speed of white particles (Vw: ⁇ m / sec), and The ratio (Vw / Vc) was determined.
  • the particle moving speed was measured in the same manner.

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Abstract

Provided are a particle dispersion for display which gives white displays having a high reflectance and in which the white particles for display are inhibited from sedimenting and an image display device equipped with the particle dispersion. The particle dispersion for display comprises: white particles for display which comprise a white pigment and a resin, have a white pigment content of 30-90 mass% and a volume-average particle diameter of 100-500 nm, and satisfy relationship (1): 400≥6kT/(πd3(ρp-ρs)g)≥30; colored particles for display which are of two or more kinds other than white and which move in accordance with an electric field; and a dispersion medium. In relationship (1), k indicates the Boltzmann constant, T indicates the absolute temperature, 298 (K), d indicates the volume-average particle diameter of the white particles for display, ρp indicates the specific gravity of the white particles for display, ρs indicates the specific gravity of the dispersion medium, and g indicates the gravitational acceleration.

Description

表示用粒子分散液、画像表示装置、電子機器、展示用媒体、及びカード媒体Display particle dispersion, image display device, electronic device, display medium, and card medium
　本発明は、多色表示が可能な画像表示装置に利用される表示用粒子分散液、及びそれを有する画像表示装置に関する。
　また、本発明は、画像表示装置を備える電子機器、展示用媒体、及びカード媒体に関する。 The present invention relates to a display particle dispersion used in an image display device capable of multicolor display, and an image display device having the same.
The present invention also relates to an electronic device including an image display device, a display medium, and a card medium.
　従来から、繰り返し書換えの可能な表示技術として、電気泳動を用いた表示技術が提案されている。このような表示技術としては、例えば、一対の基板間に、分散液を封入すると共に、この分散液内に帯電した粒子からなる粒子群を分散した構成の画像表示装置が知られている。 Conventionally, a display technique using electrophoresis has been proposed as a display technique that can be rewritten repeatedly. As such a display technique, for example, an image display device having a configuration in which a dispersion liquid is sealed between a pair of substrates and particle groups made of charged particles are dispersed in the dispersion liquid is known.
　このような画像表示装置では、画像に応じた電圧を基板間に印加することにより、帯電した粒子を移動させて、粒子の色のコントラストとして画像の表示を行っている（例えば、特開２００４－３３３５８９号公報、特開２００５－１０７１４６号公報、特開２００５－１２８１４１号公報、及び特開２００３－００５２２８号公報を参照）。また、表示用白色粒子として酸化チタン粒子などの顔料を含む複合粒子を用いることが知られている（例えば、特開２００７－０４１０７８号公報及び特開２００７－０３３６３０号公報を参照）。 In such an image display device, a voltage corresponding to an image is applied between the substrates to move the charged particles and display the image as the color contrast of the particles (for example, Japanese Patent Application Laid-Open No. 2004-2004). No. 333589, JP 2005-107146, JP 2005-128141, and JP 2003-005228). In addition, it is known to use composite particles containing pigments such as titanium oxide particles as display white particles (see, for example, Japanese Patent Application Laid-Open Nos. 2007-041078 and 2007-033630).
　しかしながら、白表示の反射率が高い表示用白色粒子を調製し、表示用着色粒子の移動により表示可能とする画像表示装置を作製したところ、表示用白色粒子の沈降が発生してしまう一方で、表示用白色粒子の沈降の発生を抑えようとすると、白表示の反射率が低下してしまうのが現状である。 However, when white display particles having a high white display reflectance are prepared and an image display device that can be displayed by moving the display colored particles is produced, sedimentation of the display white particles occurs. At present, the reflectance of white display is lowered when it is attempted to suppress the precipitation of the white particles for display.
　そこで、本発明は、上記問題を解決するためになされたものであり、白表示の反射率が高く、且つ表示用白色粒子の沈降を抑制した表示用粒子分散液、及びそれを備える画像表示装置を提供することを課題とする。
　また、本発明は、この画像表示装置を備える電子機器、展示用媒体、及びカード媒体を提供することを課題とする。 Accordingly, the present invention has been made to solve the above-described problem, and a display particle dispersion having a high white display reflectance and suppressing the precipitation of display white particles, and an image display apparatus including the same. It is an issue to provide.
Moreover, this invention makes it a subject to provide an electronic device provided with this image display apparatus, a display medium, and a card | curd medium.
　上記課題を達成するための手段は下記のとおりである。
　＜１＞　白色顔料及び樹脂を含む表示用白色粒子であって、前記白色顔料の含有量（前記白色顔料の質量/（前記白色顔料及び前記樹脂の総質量））が３０質量％以上９０質量％以下であり、体積平均粒径が１００ｎｍ以上５００ｎｍ以下であり、且つ下記式（１）を満たす表示用白色粒子と、
　電界に応じて移動する表示用着色粒子であって、白色を除く２種以上の表示用着色粒子と、
　前記表示用着色粒子及び前記表示用白色粒子を分散する分散媒と、
　を有する表示用粒子分散液である。
・式（１）　４００≧６ｋＴ/（πｄ３（ρｐ－ρｓ）ｇ）≧３０
（式（１）中、ｋはボルツマン係数（Ｊ・Ｋ－１）を示す。Ｔは絶対温度２９８（Ｋ）を示す。ｄは前記表示用白色粒子の体積平均粒径（ｎｍ）を示す。ρｐは前記表示用白色粒子の比重（ｇ／ｃｍ３）を示す。ρｓは前記分散媒の比重（ｇ／ｃｍ３）を示す。ｇは重力加速度（ｍ／ｓ２）を示す。） Means for achieving the above object are as follows.
<1> A white particle for display containing a white pigment and a resin, wherein the content of the white pigment (mass of the white pigment / (total mass of the white pigment and the resin)) is 30% by mass or more and 90% by mass. White particles for display having a volume average particle size of 100 nm to 500 nm and satisfying the following formula (1):
Display colored particles that move in response to an electric field, two or more types of display colored particles excluding white,
A dispersion medium for dispersing the display colored particles and the display white particles;
It is a particle dispersion for display which has.
Formula (1) 400 ≧ 6 kT / (πd 3 (ρp−ρs) g) ≧ 30
(In formula (1), k represents the Boltzmann coefficient (J · K −1 ), T represents the absolute temperature 298 (K), and d represents the volume average particle diameter (nm) of the white particles for display. ρp is .ρs showing a specific gravity (g / cm 3) of the display for white particles exhibit specific gravity (g / cm 3) .g showing a gravity acceleration (m / s 2) of the dispersion medium.)
　＜２＞　前記白色顔料が、酸化チタンである前記＜１＞に記載の表示用粒子分散液である。 <2> The display particle dispersion according to <1>, wherein the white pigment is titanium oxide.
　＜３＞　前記表示用白色粒子と前記表示用着色粒子との電界に応じて移動する移動速度比（前記表示用白色粒子の移動速度Ｖｗ／前記表示用着色粒子の移動速度Ｖｃ）が、０．２以下である前記＜１＞又は＜２＞に記載の表示用粒子分散液である。 <3> A moving speed ratio (moving speed Vw of the white particles for display / moving speed Vc of the colored particles for display) that moves according to the electric field between the white particles for display and the colored particles for display is 0. The particle dispersion for display according to <1> or <2>, which is 2 or less.
　＜４＞　前記分散媒の粘度が、５ｍＰａ・ｓ以下である前記＜１＞～＜３＞のいずれか１つに記載の表示用粒子分散液である。 <4> The display particle dispersion according to any one of <1> to <3>, wherein the dispersion medium has a viscosity of 5 mPa · s or less.
　＜５＞　前記分散媒が、シリコーンオイルである前記＜１＞～＜４＞のいずれか１つに記載の表示用粒子分散液である。 <5> The display particle dispersion according to any one of <1> to <4>, wherein the dispersion medium is silicone oil.
　＜６＞　前記表示用白色粒子の比重が２．１ｇ／ｃｍ３以上４．３ｇ／ｃｍ３以下である前記＜１＞～＜５＞のいずれか１項に記載の表示用粒子分散液。
　＜７＞　前記分散媒の比重が０．６ｇ／ｃｍ３以上１．２ｇ／ｃｍ３以下である前記＜１＞～＜６＞のいずれか１項に記載の表示用粒子分散液。 <6> The display particle dispersion according to any one of <1> to <5>, wherein the white particles for display have a specific gravity of 2.1 g / cm 3 or more and 4.3 g / cm 3 or less.
<7> The display particle dispersion according to any one of <1> to <6>, wherein the specific gravity of the dispersion medium is 0.6 g / cm 3 or more and 1.2 g / cm 3 or less.
　＜８＞　少なくとも一方が透光性を有する一対の基板と、
　前記一対の基板間に封入された前記＜１＞～＜７＞のいずれか１つに記載の表示用粒子分散液と、
　前記一対の基板間に、前記表示用着色粒子を移動させる強度の電界を付与する電界発生手段と、
　を備えた画像表示装置である。 <8> a pair of substrates at least one of which has translucency;
The display particle dispersion according to any one of <1> to <7>, which is sealed between the pair of substrates;
An electric field generating means for applying an electric field having an intensity for moving the display colored particles between the pair of substrates;
It is an image display apparatus provided with.
　＜９＞　前記＜８＞に記載の画像表示装置を備えた電子機器である。
　＜１０＞　前記＜８＞に記載の画像表示装置を備えた展示用媒体である。
　＜１１＞　前記＜８＞に記載の画像表示装置を備えたカード媒体である。 <9> An electronic device including the image display device according to <8>.
<10> An exhibition medium including the image display device according to <8>.
<11> A card medium including the image display device according to <8>.
　本発明の一態様によれば、白表示の反射率が高く、且つ表示用白色粒子の沈降を抑制した表示用粒子分散液、及びそれを備える画像表示装置を提供することができる。
　また、本発明の別の態様によれば、この画像表示装置を備える電子機器、展示用媒体、及びカード媒体を提供することができる。 According to one embodiment of the present invention, it is possible to provide a display particle dispersion that has a high white display reflectance and suppresses settling of display white particles, and an image display device including the same.
In addition, according to another aspect of the present invention, an electronic device, an exhibition medium, and a card medium including the image display device can be provided.
図１は、本発明の一実施形態に係る画像表示装置の概略構成図である。FIG. 1 is a schematic configuration diagram of an image display apparatus according to an embodiment of the present invention. 図２は、本発明の一実施形態に係る画像表示装置における、印加する電圧と表示用着色粒子の移動量（表示濃度）との関係を模式的に示す線図である。FIG. 2 is a diagram schematically showing a relationship between an applied voltage and a moving amount (display density) of display colored particles in the image display apparatus according to the embodiment of the present invention. 本実施形態に係る画像表示装置の基板間へ印加する電圧態様と、表示用着色粒子の移動態様とを模式的に示す説明図である。It is explanatory drawing which shows typically the voltage aspect applied between the board | substrates of the image display apparatus which concerns on this embodiment, and the movement aspect of the colored particle for a display.
　以下、本発明について詳細に説明する。 Hereinafter, the present invention will be described in detail.
表示用粒子分散液
　本発明の表示用粒子分散液は、表示用白色粒子と、電界に応じて移動する表示用着色粒子であって、白色を除く２種以上の表示用着色粒子と、表示用着色粒子及び表示用白色粒子を分散する分散媒と、を有する。
　表示用白色粒子は、白色顔料及び樹脂を含む表示用白色粒子であって、白色顔料の含有量（白色顔料の質量/（白色顔料及び樹脂の総質量））が３０質量％以上９０質量％以下であり、体積平均粒径が１００ｎｍ以上５００ｎｍ以下であり、且つ下記式（１）を満たすものである。 Display Particle Dispersion The display particle dispersion of the present invention is a display white particle, a display colored particle that moves in response to an electric field, and two or more types of display colored particles excluding white, and a display A dispersion medium for dispersing the colored particles and the white particles for display.
The white particles for display are white particles for display containing a white pigment and a resin, and the content of the white pigment (mass of white pigment / (total mass of white pigment and resin)) is 30% by mass or more and 90% by mass or less. The volume average particle size is 100 nm or more and 500 nm or less, and the following formula (1) is satisfied.
　ここで、白色顔料の含有量及び表示用白色粒子の体積平均粒径を上記範囲とすることにより、表示用白色粒子が高い白反射率が実現される。一方で、表示用白色粒子が式（１）を満たすことにより、表示用白色粒子のブラウン運動による拡散と自重による沈降とが平衡状態となり、見かけ上、分散液中で浮遊状態となる。 Here, by setting the content of the white pigment and the volume average particle diameter of the white particles for display within the above ranges, the white reflectance of the white particles for display is realized. On the other hand, when the display white particles satisfy the formula (1), the diffusion due to the Brownian motion of the display white particles and the sedimentation due to its own weight are in an equilibrium state, and apparently become a floating state in the dispersion.
　このため、本発明の表示用粒子分散液では、白色顔料及び樹脂を含む表示用白色粒子において、白色顔料の含有量及び表示用白色粒子の体積平均粒径を上記範囲とした上で、式（１）を満たすようにすることにより、白表示の反射率が高く、且つ表示用白色粒子の沈降を抑制することができる。
　また、本発明の表示用粒子分散液では、表示用白色粒子の沈降が抑制され、分散安定性が増すことから、表示用着色粒子の移動を妨げ難くなると考えられ、表示用着色粒子の表示応答性も向上する。 Therefore, in the display particle dispersion of the present invention, in the display white particles containing the white pigment and the resin, the content of the white pigment and the volume average particle diameter of the display white particles are within the above ranges, By satisfying 1), the reflectance of white display is high and the sedimentation of white particles for display can be suppressed.
Further, in the display particle dispersion of the present invention, since the precipitation of the display white particles is suppressed and the dispersion stability is increased, it is considered difficult to prevent the movement of the display colored particles. Also improves.
　以下、本発明の表示用粒子分散液の各構成要素について説明する。 Hereinafter, each component of the display particle dispersion of the present invention will be described.
表示用着色粒子
　表示用着色粒子は、電界に応じて移動する２種以上の表示用着色粒子であって、白色を除く表示用着色粒子である。そして、表示用着色粒子は、例えば、正又は負に帯電されており、予め定められた電界強度以上の電界が形成されることで分散媒中を移動可能なものである。また、２種以上の表示用着色粒子は、互いに色が異なると共に、帯電特性が異なる粒子である。この帯電特性が異なるとは、互いの粒子の帯電極性若しくは帯電量が異なること、又は、帯電極性及び帯電量の双方が異なることを示している。
　なお、画像表示装置における表示色の変化は、この表示用着色粒子の分散媒中の移動によって生じる。 Display colored particles Display colored particles are two or more types of display colored particles that move in response to an electric field, and are display colored particles excluding white. The colored particles for display are, for example, positively or negatively charged, and can move in the dispersion medium by forming an electric field that is equal to or higher than a predetermined electric field strength. Further, the two or more kinds of display colored particles are particles having different colors and different charging characteristics. The difference in the charging characteristics indicates that the charging polarity or the charging amount of the particles is different, or that both the charging polarity and the charging amount are different.
The change in display color in the image display device is caused by the movement of the display colored particles in the dispersion medium.
表示用着色粒子の組成
　表示用着色粒子としては、例えば、樹脂粒子、樹脂粒子の表面に着色剤を固定したもの、又は樹脂中に着色剤を含有する粒子が挙げられる。表示用着色粒子としては、その他、絶縁性の金属酸化物粒子（例えばガラスビーズ、アルミナ、酸化チタン等の粒子）、又はプラズモン発色機能を有する金属コロイド粒子等も挙げられる。 Composition of display colored particles Examples of the display colored particles include resin particles, those obtained by fixing a colorant on the surface of the resin particles, and particles containing a colorant in the resin. Other examples of the colored particles for display include insulating metal oxide particles (for example, particles such as glass beads, alumina, and titanium oxide) or metal colloid particles having a plasmon coloring function.
樹脂
　表示用着色粒子に使用する熱可塑性樹脂としては、例えば、スチレン、クロロスチレン等のスチレン類；エチレン、プロピレン、ブチレン、イソプレン等のモノオレフィン類；酢酸ビニル、プロピオン酸ビニル、安息香酸ビニル、酪酸ビニル等のビニルエステル類；アクリル酸メチル、アクリル酸エチル、アクリル酸ブチル、アクリル酸ドデシル、アクリル酸オクチル、アクリル酸フェニル、メタクリル酸メチル、メタクリル酸エチル、メタクリル酸ブチル、メタクリル酸ドデシル等のα－メチレン脂肪族モノカルボン酸エステル類；ビニルメチルエーテル、ビニルエチルエーテル、ビニルブチルエーテル等のビニルエーテル類；又は、ビニルメチルケトン、ビニルヘキシルケトン、ビニルイソプロペニルケトン等のビニルケトン類の単独重合体、又はこれらの共重合体からなる樹脂が挙げられる。
　表示用着色粒子に使用する熱硬化性樹脂としては、例えば、ジビニルベンゼンを主成分とする架橋共重合体や架橋ポリメチルメタクリレート等の架橋樹脂、フェノール樹脂、尿素樹脂、メラミン樹脂、ポリエステル樹脂、シリコーン樹脂等が挙げられる。 Resin Thermoplastic resins used for colored particles for display include, for example, styrenes such as styrene and chlorostyrene; monoolefins such as ethylene, propylene, butylene, and isoprene; vinyl acetate, vinyl propionate, vinyl benzoate, and butyric acid Vinyl esters such as vinyl; α- such as methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dodecyl methacrylate Methylene aliphatic monocarboxylic acid esters; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl butyl ether; or vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and vinyl isopropenyl ketone Polymer, or resin made of a copolymer thereof.
Examples of the thermosetting resin used for the colored particles for display include cross-linked copolymers mainly composed of divinylbenzene and cross-linked resins such as cross-linked polymethyl methacrylate, phenol resins, urea resins, melamine resins, polyester resins, and silicones. Examples thereof include resins.
　表示用着色粒子に使用する代表的な樹脂としては、例えば、ポリスチレン樹脂、スチレン－アクリル酸アルキル共重合体、スチレン－メタクリル酸アルキル共重合体、スチレン－アクリロニトリル共重合体、スチレン－ブタジエン共重合体、スチレン－無水マレイン酸共重合体、ポリエチレン樹脂、ポリプロピレン樹脂、ポリエステル樹脂、ポリウレタン樹脂、エポキシ樹脂、シリコーン樹脂、ポリアミド樹脂、変性ロジン、パラフィンワックス等が挙げられる。 Representative resins used for the display colored particles include, for example, polystyrene resins, styrene-alkyl acrylate copolymers, styrene-alkyl methacrylate copolymers, styrene-acrylonitrile copolymers, and styrene-butadiene copolymers. Styrene-maleic anhydride copolymer, polyethylene resin, polypropylene resin, polyester resin, polyurethane resin, epoxy resin, silicone resin, polyamide resin, modified rosin, paraffin wax and the like.
　特に、表示用着色粒子に使用する樹脂としては、粒子に帯電を持たせるために帯電性基を有する樹脂（以下、「帯電性基を有する高分子」と称する）が好ましく用いられる。
　帯電性基を有する高分子は、例えば、カチオン性基又はアニオン性基を有する高分子である。帯電性基としてのカチオン性基は、例えば、アミン基、４級アンモニウム基が挙げられ（これら基の塩も含む）、このカチオン基により粒子に正帯電極性が付与される。一方、帯電性基としてのアニオン性基としては、例えば、カルボキシル基、カルボン酸塩基、スルホン酸基、スルホン酸塩基、リン酸基、及びリン酸塩基が挙げられ、このアニオン性基により粒子に負帯電極性が付与される。 In particular, as the resin used for the colored particles for display, a resin having a chargeable group (hereinafter referred to as “polymer having a chargeable group”) is preferably used in order to impart charge to the particles.
The polymer having a chargeable group is, for example, a polymer having a cationic group or an anionic group. Examples of the cationic group as the charging group include an amine group and a quaternary ammonium group (including salts of these groups), and a positively charged polarity is imparted to the particles by the cationic group. On the other hand, examples of the anionic group as the chargeable group include a carboxyl group, a carboxylate group, a sulfonate group, a sulfonate group, a phosphate group, and a phosphate group. Charge polarity is imparted.
　帯電性基を有する高分子として、具体的には、例えば、帯電性基を有する単量体の単独重合体、帯電性基を有する単量体と他の単量体（帯電性基を持たない単量体）との共重合体が挙げられる。 Specific examples of the polymer having a chargeable group include, for example, a homopolymer of a monomer having a chargeable group, a monomer having a chargeable group, and another monomer (having no chargeable group). Monomer).
　帯電性基を有する単量体としては、例えば、カチオン性基を有する単量体（以下、カチオン性単量体）、アニオン性基を有する単量体（以下、アニオン性単量体）が挙げられる。 Examples of the monomer having a charging group include a monomer having a cationic group (hereinafter referred to as a cationic monomer) and a monomer having an anionic group (hereinafter referred to as an anionic monomer). It is done.
　カチオン性単量体としては、例えば、以下のものが挙げられる。具体的には、Ｎ，Ｎ－ジメチルアミノエチル（メタ）アクリレート、Ｎ，Ｎ－ジエチルアミノエチル（メタ）アクリレート、Ｎ，Ｎ－ジブチルアミノエチル（メタ）アクリレート、Ｎ，Ｎ－ヒドロキシエチルアミノエチル（メタ）アクリレート、Ｎ－エチルアミノエチル（メタ）アクリレート、Ｎ－オ クチル－Ｎ－エチルアミノエチル（メタ）アクリレート、Ｎ，Ｎ－ジヘキシルアミノエチル（メタ）アクリレート等の脂肪族アミノ基を有する（メタ）アクリレート類；Ｎ－メチルアクリルアミド、Ｎ－オクチルアクリルアミド、Ｎ－フェニルメチルアクリルアミド、Ｎ－シクロヘキシルアクリルアミド、Ｎ－フェニルアクリルアミド、Ｎ－ｐ－メトキシ－フェニルアクリルアミド、Ｎ，Ｎ－ジメチルアクリルアミド、Ｎ，Ｎ－ジブチルアクリルアミド、Ｎ－メチル－Ｎ－フェニルアクリルアミド等の（メタ）アクリルアミド類；ジメチルアミノスチレン、ジエチルアミノスチレン、ジメチルアミノメチルスチレン、ジオクチルアミノスチレン等の含窒素基を有する芳香族置換エチレン系単量体類；ビニル－Ｎ－エチル －Ｎ－フェニルアミノエチルエーテル、ビニル－Ｎ－ブチル－Ｎ－フェニルアミノエチルエーテル、トリエタノールアミンジビニルエーテル、ビニルジフェニルアミノエチルエーテル、Ｎ－ビニルヒドロキシエチルベンズアミド、ｍ－アミノフェニルビニルエーテル等の含窒素ビニルエーテル単量体類；等が挙げられる。 Examples of the cationic monomer include the following. Specifically, N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-dibutylaminoethyl (meth) acrylate, N, N-hydroxyethylaminoethyl (meta) ), Acrylate, N-ethylaminoethyl (meth) acrylate, N-octyl-N-ethylaminoethyl (meth) acrylate, N, N-dihexylaminoethyl (meth) acrylate and other aliphatic amino groups (meth) Acrylates: N-methylacrylamide, N-octylacrylamide, N-phenylmethylacrylamide, N-cyclohexylacrylamide, N-phenylacrylamide, Np-methoxy-phenylacrylamide, N, N-dimethylacrylamide, N, N-dibutyla (Meth) acrylamides such as rilamide and N-methyl-N-phenylacrylamide; aromatic substituted ethylene monomers having a nitrogen-containing group such as dimethylaminostyrene, diethylaminostyrene, dimethylaminomethylstyrene, and dioctylaminostyrene; Vinyl-N-ethyl -N-phenylaminoethyl ether, vinyl-N-butyl-N-phenylaminoethyl ether, triethanolamine divinyl ether, vinyl diphenylaminoethyl ether, N-vinylhydroxyethylbenzamide, m-aminophenyl vinyl ether Nitrogen-containing vinyl ether monomers such as;
　カチオン単量体の例としては、含窒素複素環式化合物類も好適に挙げられるが、このうちＮ－ビニルピロール等のピロール類；Ｎ－ビニル－２－ピロリン、Ｎ－ビニル－３－ピロリン等のピロリン類；Ｎ－ビニルピロリジン、ビニルピロリジンアミノエーテル、Ｎ－ビニル－２－ピロリドン等のピロリジン類；Ｎ－ビニル－２－メチルイミダゾール等のイミダゾール類；Ｎ－ビニルイミダゾリン等のイミダゾリン類；Ｎ－ビニルインドール等のインドール類；Ｎ－ビニルインドリン等のインドリン類；Ｎ－ビニルカルバゾール、３，６－ジブロム－Ｎ－ビニルカルバゾール等のカルバゾール類；２－ビニルピリジン、４－ビニルピリジン、２－メチル－５－ビニルピロジン等のピリジン類；（メタ）アクリルピペリジン、Ｎ－ビニルピペリドン、Ｎ－ビニルピペラジン等のピペリジン類；２－ビニルキノリン、４－ビニルキノリン等のキノリン類；Ｎ－ビニルピラゾール、Ｎ－ビニルピラゾリン等のピラゾール類；２－ビニルオキサゾール等のオキサゾール類；４－ビニルオキサジン、モルホリノエチル（メタ）アクリレート等のオキサジン類；などが特に好ましい。 Preferred examples of the cationic monomer include nitrogen-containing heterocyclic compounds, among which pyrroles such as N-vinylpyrrole; N-vinyl-2-pyrroline, N-vinyl-3-pyrroline, etc. Pyrrolines; N-vinyl pyrrolidine, vinyl pyrrolidine amino ether, pyrrolidines such as N-vinyl-2-pyrrolidone; imidazoles such as N-vinyl-2-methylimidazole; imidazolines such as N-vinyl imidazoline; N- Indoles such as vinyl indole; Indolines such as N-vinylindoline; N-vinylcarbazole, carbazoles such as 3,6-dibromo-N-vinylcarbazole; 2-vinylpyridine, 4-vinylpyridine, 2-methyl- Pyridines such as 5-vinylpyridine; (meth) acrylic piperidine, N-vinylpiperidine Piperidines such as N-vinylpiperazine; quinolines such as 2-vinylquinoline and 4-vinylquinoline; pyrazoles such as N-vinylpyrazole and N-vinylpyrazoline; oxazoles such as 2-vinyloxazole; 4-vinyl Oxazines such as oxazine and morpholinoethyl (meth) acrylate;
　一方、アニオン性単量体としては、例えば、カルボン酸モノマー、スルホン酸モノマー、リン酸モノマー等が挙げられる。
　カルボン酸モノマーとしては、例えば、例えば、(メタ)アクリル酸、クロトン酸、イタコン酸、マレイン酸、フマール酸、及びシトラコン酸、並びに、それらの無水物、そのモノアルキルエステル、カルボキシエチルビニルエーテル、又はカルボキシプロピルビニルエーテルの如きカルボキシル基を持つビニルエーテル類、及びその塩等が挙げられる。
　スルホン酸モノマーとしては、例えば、スチレンスルホン酸、２－アクリルアミド－２－メチルプロパンスルホン酸、３－スルホプロピル（メタ）アクリックアシッドエステル、ビス－（３－スルホプロピル）－イタコニックアシッドエステル等及びその塩が挙げられる。また、スルホン酸モノマーの例としては、その他２－ヒドロキシエチル（メタ）アクリル酸の硫酸モノエステル及びその塩も挙げられる。
　リン酸モノマーの例としては、ビニルホスホン酸、ビニルホスフェート、アシッドホスホキシエチル（メタ）アクリレート、アシッドホスホキシプロピル（メタ）アクリレート、ビス（メタクリロキシエチル）ホスフェート、ジフェニル－２－メタクリロイロキシエチルホスフェート、ジフェニル－２－アクリロイロキシエチルホスフェート、ジブチル－２－メタクリロイロキシエチルホスフェート、ジブチル－２－アクリロイロキシエチルホスフェート、ジオクチル－２－（メタ）アクリロイロキシエチルホスフェート等が挙げられる。 On the other hand, examples of the anionic monomer include a carboxylic acid monomer, a sulfonic acid monomer, and a phosphoric acid monomer.
Examples of the carboxylic acid monomer include, for example, (meth) acrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, and citraconic acid, and anhydrides thereof, monoalkyl esters thereof, carboxyethyl vinyl ether, or carboxy Examples thereof include vinyl ethers having a carboxyl group such as propyl vinyl ether, and salts thereof.
Examples of the sulfonic acid monomer include styrene sulfonic acid, 2-acrylamido-2-methylpropane sulfonic acid, 3-sulfopropyl (meth) click acid ester, bis- (3-sulfopropyl) -itaconic acid ester, and the like. The salt is mentioned. Examples of the sulfonic acid monomer include sulfuric acid monoesters of 2-hydroxyethyl (meth) acrylic acid and salts thereof.
Examples of phosphoric acid monomers include vinyl phosphonic acid, vinyl phosphate, acid phosphoxyethyl (meth) acrylate, acid phosphooxypropyl (meth) acrylate, bis (methacryloxyethyl) phosphate, diphenyl-2-methacryloyloxyethyl phosphate Diphenyl-2-acryloyloxyethyl phosphate, dibutyl-2-methacryloyloxyethyl phosphate, dibutyl-2-acryloyloxyethyl phosphate, dioctyl-2- (meth) acryloyloxyethyl phosphate, and the like.
　帯電性基を有する単量体と併用してもよい他の単量体としては、例えば、水溶性単量体（例えばヒドロキシル基を有する単量体等）が挙げられ、具体的には、例えば、ヒドロキシエチル（メタ）アクリレート、ヒドロキシブチル（メタ）アクリレート、エチレンオキシドユニットを持つモノマー（例えばテトラエチレングリコールモノメチルエーテル（メタ）アクリレートなどのアルキルオキシオリゴエチレングリコールの（メタ）アクリレート、又はポリエチレングリコールの片末端（メタ）アクリレート）、（メタ）アクリル酸及びその塩、マレイン酸、（メタ）アクリルアミド－２－メチルプロパンスルホン酸及びその塩、ビニルスルホン酸及びその塩、並びにビニルピロリドンなどが挙げられる。
　他の単量体の例としては、その他周知の非イオン性の単量体が挙げられる。 Examples of other monomers that may be used in combination with the monomer having a chargeable group include water-soluble monomers (for example, monomers having a hydroxyl group). Specifically, for example, , Hydroxyethyl (meth) acrylate, hydroxybutyl (meth) acrylate, a monomer having an ethylene oxide unit (eg, (oxy) alkyloxyoligoethylene glycol (meth) acrylate such as tetraethylene glycol monomethyl ether (meth) acrylate), or one end of polyethylene glycol (Meth) acrylate), (meth) acrylic acid and salts thereof, maleic acid, (meth) acrylamido-2-methylpropanesulfonic acid and salts thereof, vinylsulfonic acid and salts thereof, and vinylpyrrolidone.
Examples of other monomers include other well-known nonionic monomers.
　なお、「（メタ）アクリル」は「アクリル」及び「メタクリル」の双方の表記である。「（メタ）アクリロ」は「アクリロ」及び「メタクリロ」の双方の表記である。「（メタ）アクリレート」は「アクリレート」及び「メタクリレート」の双方の表記である。 “(Meth) acryl” is a notation for both “acryl” and “methacryl”. “(Meth) acrylo” is a notation for both “acrylo” and “methacrylo”. “(Meth) acrylate” is a notation for both “acrylate” and “methacrylate”.
着色剤
　表示用着色粒子に使用する着色剤としては、有機若しくは無機の顔料や、油溶性染料等が挙げられる。
　着色剤としては、例えば、マグネタイト、フェライト等の磁性紛、並びに、カーボンブラック、酸化チタン、酸化マグネシウム、酸化亜鉛、フタロシアニン銅系シアン色材、アゾ系イエロー色材、アゾ系マゼンタ色材、キナクリドン系マゼンタ色材、レッド色材、グリーン色材、ブルー色材等の公知の着色剤が挙げられる。
　着色剤として具体的には、例えば、アニリンブルー、カルコイルブルー、クロムイエロー、ウルトラマリンブルー、デュポンオイルレッド、キノリンイエロー、メチレンブルークロリド、フタロシアニンブルー、マラカイトグリーンオキサレート、ランプブラック、ローズベンガル、Ｃ．Ｉ．ピグメント・レッド４８：１、Ｃ．Ｉ．ピグメント・レッド１２２Ｃ．Ｉ．ピグメント・レッド５７：１、Ｃ．Ｉ．ピグメント・イエロー９７、Ｃ．ブルー１５：１、Ｃ．Ｉ．ピグメント・ブルー１５：３、等が代表的なものとして挙げられる。 Colorant Examples of the colorant used for the colored particles for display include organic or inorganic pigments and oil-soluble dyes.
Examples of the colorant include magnetic powder such as magnetite and ferrite, and carbon black, titanium oxide, magnesium oxide, zinc oxide, phthalocyanine copper-based cyan color material, azo-based yellow color material, azo-based magenta color material, and quinacridone-based material. Known colorants such as a magenta color material, a red color material, a green color material, and a blue color material can be used.
Specific examples of the colorant include aniline blue, calcoyl 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 122C. I. Pigment red 57: 1, C.I. I. Pigment yellow 97, C.I. Blue 15: 1, C.I. I. Pigment Blue 15: 3 is a typical example.
　着色剤の含有量は、例えば、表示用着色粒子の構成成分である樹脂に対し、１０質量％以上９９質量％以下がよく、好ましくは３０質量％以上９９質量％以下である。 The content of the colorant is, for example, from 10% by mass to 99% by mass and preferably from 30% by mass to 99% by mass with respect to the resin that is a component of the colored particles for display.
その他成分
　表示用着色粒子には、必要に応じて、帯電制御剤を含んでもよい。帯電制御剤としては、電子写真用トナー材料に使用される公知のものが挙げられ、例えば、セチルピリジルクロライド、ＢＯＮＴＲＯＮ　Ｐ－５１、ＢＯＮＴＲＯＮ　Ｐ－５３、ＢＯＮＴＲＯＮ　Ｅ－８４、ＢＯＮＴＲＯＮ　Ｅ－８１（以上、オリエント化学工業社製）等の第４級アンモニウム塩、サリチル酸系金属錯体、フェノール系縮合物、テトラフェニル系化合物、酸化金属粒子、各種カップリング剤により表面処理された酸化金属粒子が挙げられる。 Other Components The colored particles for display may contain a charge control agent as necessary. Examples of the charge control agent include known ones used for toner materials for electrophotography. For example, cetylpyridyl chloride, BONTRON P-51, BONTRON P-53, BONTRON E-84, BONTRON E-81 (above, Quaternary ammonium salts such as Orient Chemical Industry Co., Ltd., salicylic acid metal complexes, phenol condensates, tetraphenyl compounds, metal oxide particles, and metal oxide particles surface-treated with various coupling agents.
　表示用着色粒子の表面には、必要に応じて、外添剤を付着させてもよい。外添剤の色は、表示用着色粒子の色に影響を与えないように、透明であることが好ましい。
　外添剤の例としては、酸化ケイ素（シリカ）、酸化チタン、アルミナ等の金属酸化物等の無機粒子が挙げられる。外添剤は、表示用着色粒子の帯電性、流動性、又は環境依存性等を調整するために、カップリング剤やシリコーンオイルで表面処理してもよい。
　カップリング剤の例としては、アミノシラン系カップリング剤、アミノチタン系カップリング剤、ニトリル系カップリング剤等の正帯電性のカップリング剤、並びに、窒素原子を含まない（窒素以外の原子で構成される）シラン系カップリング剤、チタン系カップリング剤、エポキシシランカップリング剤、アクリルシランカップリング剤等の負帯電性のカップリング剤が挙げられる。
　シリコーンオイルの例としては、アミノ変性シリコーンオイル等の正帯電性のシリコーンオイル、並びに、ジメチルシリコーンオイル、アルキル変性シリコーンオイル、α－メチルスルホン変性シリコーンオイル、メチルフェニルシリコーンオイル、クロルフェニルシリコーンオイル、及びフッ素変性シリコーンオイル等の負帯電性のシリコーンオイルが挙げられる。
　なお、これらカップリング剤又はシリコーンオイルは、外添剤の所望の抵抗に応じて選択される。 If necessary, an external additive may be attached to the surface of the display colored particles. The color of the external additive is preferably transparent so as not to affect the color of the colored particles for display.
Examples of the external additive include inorganic particles such as metal oxides such as silicon oxide (silica), titanium oxide, and alumina. The external additive may be surface-treated with a coupling agent or silicone oil in order to adjust the charging property, fluidity, environment dependency, etc. of the colored particles for display.
Examples of coupling agents include positively chargeable coupling agents such as aminosilane coupling agents, aminotitanium coupling agents, and nitrile coupling agents, and no nitrogen atoms (consisting of atoms other than nitrogen). And negatively chargeable coupling agents such as silane coupling agents, titanium coupling agents, epoxy silane coupling agents, and acrylic silane coupling agents.
Examples of silicone oils include positively charged silicone oils such as amino-modified silicone oils, and dimethyl silicone oils, alkyl-modified silicone oils, α-methylsulfone modified silicone oils, methylphenyl silicone oils, chlorophenyl silicone oils, and Examples include negatively charged silicone oils such as fluorine-modified silicone oils.
These coupling agents or silicone oils are selected according to the desired resistance of the external additive.
　外添剤の一次粒子径は、例えば、１ｎｍ以上１００ｎｍ以下であることがよく、好ましくは５ｎｍ以上５０ｎｍ以下であるが、これに限定されない。 The primary particle size of the external additive is, for example, preferably from 1 nm to 100 nm, and preferably from 5 nm to 50 nm, but is not limited thereto.
　外添剤の外添量は、例えば、表示用着色粒子１００質量部に対して、０．０１質量部以上３質量部以下であることがよく、好ましくは０．０５質量部以上１質量部以下である。
　外添剤の外添量は、表示用着色粒子の粒径と外添剤の粒径の兼ね合いから調整することがよい。そして、外添剤の外添量を上記範囲にすると、表示用着色粒子表面から外添剤の少なくとも一部が遊離し、これが他方の表示用着色粒子の表面に付着して、所望の帯電特性が得られなくなるのが防止され易くなる点で有利である。 The external addition amount of the external additive is, for example, preferably 0.01 parts by mass or more and 3 parts by mass or less, and preferably 0.05 parts by mass or more and 1 part by mass or less with respect to 100 parts by mass of the display colored particles. It is.
The external addition amount of the external additive is preferably adjusted based on the balance between the particle diameter of the colored particles for display and the particle diameter of the external additive. When the amount of the external additive is within the above range, at least a part of the external additive is released from the surface of the display colored particles, and this adheres to the surface of the other display colored particles, so that desired charging characteristics are obtained. This is advantageous in that it is easily prevented from being obtained.
　外添剤は、複数種類の表示用着色粒子の何れか１種にだけ添加してもよいし、複数種又は全種類の表示用着色粒子へ外添してもよい。全種類の表示用着色粒子の表面に外添剤を添加する場合は、表示用着色粒子表面に外添剤を衝撃力で打込んだり、表示用着色粒子表面を加熱して外添剤を表示用着色粒子表面に強固に固着したりすることが好ましい。これにより、外添剤が表示用着色粒子から遊離し、異極性の外添剤が強固に凝集して、電界で解離させることが困難な外添剤の凝集体を形成することが防止され、ひいては画質劣化が防止され易くなる点で有利である。 The external additive may be added to any one of a plurality of types of display coloring particles, or may be externally added to a plurality of types or all types of display coloring particles. When adding external additives to the surface of all kinds of colored particles for display, the external additive is applied to the surface of the colored particles for display with impact force or the surface of the colored particles for display is heated to display the external additive. It is preferable to firmly adhere to the colored particle surface. Thereby, the external additive is released from the colored particles for display, and the external additive of different polarity is firmly aggregated to prevent formation of an aggregate of the external additive that is difficult to dissociate with an electric field, As a result, it is advantageous in that image quality deterioration is easily prevented.
表示用着色粒子の特性
　表示用着色粒子の体積平均粒径は、例えば、０．０５μｍ以上２０μｍ以下であることがよく、好ましくは０．１μｍ以上１μｍ以下である。なお、表示用着色粒子の大きさは、特に制限はなく、用途に応じて、好ましい範囲を決定することができる。 Characteristics of Displayed Colored Particles The volume average particle size of the colored particles for display is, for example, preferably from 0.05 μm to 20 μm, and preferably from 0.1 μm to 1 μm. In addition, the magnitude | size of the colored particle for a display does not have a restriction | limiting in particular, A preferable range can be determined according to a use.
　表示用粒子分散液中での表示用着色粒子の濃度は、所望の表示色が得られる濃度であれば特に限定されるものではなく、例えば、０．０１質量％以上５０質量％以下であることがよい。
　なお、表示用着色粒子の濃度は、画像表示装置の一対の基板間に封入された状態での表示用粒子分散液中の濃度としても上記範囲であることがよい。また、表示用着色粒子の濃度は、画像表示装置の一対の基板間の距離により調整することが有効である。所望の色相を得るために、画像表示装置の一対の基板間の距離が大きくなるほど粒子濃度は少なくなり、当該距離が小さくほど粒子濃度は多くなる。 The concentration of the display colored particles in the display particle dispersion is not particularly limited as long as a desired display color can be obtained. For example, the concentration is 0.01% by mass or more and 50% by mass or less. Is good.
The concentration of the colored particles for display is preferably within the above range as the concentration in the display particle dispersion in a state of being enclosed between a pair of substrates of the image display device. Further, it is effective to adjust the concentration of the display colored particles by the distance between the pair of substrates of the image display device. In order to obtain a desired hue, the particle concentration decreases as the distance between the pair of substrates of the image display device increases, and the particle concentration increases as the distance decreases.
表示用着色粒子の製造方法
　表示用着色粒子を製造する方法としては、従来公知のどの方法を用いてもよい。具体的には、例えば、以下に示す方法が挙げられる。
　１）特開平７－３２５４３４公報記載のように、樹脂、顔料及び必要に応じて帯電制御剤を目的とする混合比になるように計量し、樹脂を加熱溶融させた後に顔料を添加して混合、分散させ、冷却した後、ジェットミル、ハンマーミル、又はターボミル等の粉砕機により、表示用着色粒子を製造する方法。
　２）懸濁重合、乳化重合、分散重合等の重合法、又はコアセルベーション、メルトディスパージョン、もしくはエマルジョン凝集法により、表示用着色粒子を製造する方法。
　３）樹脂が可塑性を有している場合、分散媒が沸騰せず、かつ、樹脂、着色剤及び必要に応じて帯電制御剤の少なくとも一方の分解点よりも低温で、樹脂、着色剤、分散媒及び必要に応じて帯電制御剤の原材料を分散及び混錬して、粒子を製造する方法（具体的には、例えば、流星型ミキサー、ニーダー等で樹脂、着色剤、及び必要に応じて帯電制御剤を分散媒中で加熱溶融し、樹脂の溶媒溶解度の温度依存性を利用して、溶融混合物を撹拌しながら冷却し、凝固及び／又は析出させて、表示用着色粒子を製造する方法）。
　４）分散及び混練のための粒状メディアを装備した適当な容器、例えばアトライター又は加熱したボールミル等の加熱された振動ミル中に上記の原材料を投入し、この容器を好ましい温度範囲、例えば８０℃以上１６０℃以下で分散及び混練して、粒子を作製する方法。
　なお、粒状メディアとしては、例えば、ステンレス鋼、炭素鋼等の鋼、アルミナ、ジルコニア、シリカ等が望ましく用いられる。粒状メデイアを利用した方法によって、表示用着色粒子を製造するには、あらかじめ流動状態にした原材料をさらに粒状メデイアによって容器内に分散させた後、分散媒を冷却して分散媒から着色剤を含む樹脂を沈殿させることがよい。粒状メデイアは、冷却中及び冷却後にも引き続き運動状態を保ちながら、剪断及び／又は、衝撃を発生させ、得られる表示用着色粒子の粒径を小さくすることがよい。 Manufacturing method of colored particles for display Any conventionally known method may be used as a method of manufacturing the colored particles for display. Specifically, the method shown below is mentioned, for example.
1) As described in JP-A-7-325434, the resin, the pigment and, if necessary, the charge control agent are weighed to the desired mixing ratio, the resin is heated and melted, and then the pigment is added and mixed A method of producing colored particles for display after being dispersed and cooled, and then by a pulverizer such as a jet mill, a hammer mill, or a turbo mill.
2) A method for producing colored particles for display by polymerization methods such as suspension polymerization, emulsion polymerization, dispersion polymerization, or coacervation, melt dispersion, or emulsion aggregation.
3) When the resin has plasticity, the dispersion medium does not boil, and the resin, the colorant, and the dispersion are at a temperature lower than the decomposition point of at least one of the resin, the colorant, and if necessary, the charge control agent. A method of producing particles by dispersing and kneading the medium and, if necessary, the raw material of the charge control agent (specifically, for example, a meteor mixer, a kneader, etc. A method of producing colored particles for display by heating and melting a control agent in a dispersion medium, cooling the molten mixture while stirring, solidifying and / or precipitating using the temperature dependence of the solvent solubility of the resin) .
4) The above raw materials are put into a suitable container equipped with granular media for dispersion and kneading, for example a heated vibration mill such as an attritor or a heated ball mill, and the container is placed in a preferred temperature range, for example 80 ° C. A method of producing particles by dispersing and kneading at 160 ° C. or lower.
As the granular media, for example, steel such as stainless steel and carbon steel, alumina, zirconia, silica and the like are desirably used. In order to produce colored particles for display by a method using granular media, the raw material previously fluidized is further dispersed in the container by granular media, and then the dispersion medium is cooled to contain the colorant from the dispersion medium. It is better to precipitate the resin. It is preferable that the granular media generate shear and / or impact while maintaining the motion state during and after cooling, and reduce the particle size of the resulting colored particles for display.
表示用白色粒子
　表示用白色粒子は、下記式（１）を満たす粒子であり、白表示の反射率が高く、且つ表示用白色粒子の沈降を抑制する観点から、好ましくは式（１－２）、より好ましくは（１－３）を満たす粒子である。 White particles for display The white particles for display satisfy the following formula (1). From the viewpoint of high white display reflectivity and suppression of settling of the white particles for display, the formula (1-2) is preferable. More preferably, the particles satisfy (1-3).
・式（１）　４００≧６ｋＴ/（πｄ３（ρｐ－ρｓ）ｇ）≧３０
・式（１－２）　２００≧６ｋＴ/（πｄ３（ρｐ－ρｓ）ｇ）≧４０
・式（１－３）　１００≧６ｋＴ/（πｄ３（ρｐ－ρｓ）ｇ）≧４０
（式（１）～（１－３）中、ｋはボルツマン係数（Ｊ・Ｋ－１）を示す。Ｔは絶対温度２９８（Ｋ）を示す。ｄは表示用白色粒子の体積平均粒径（ｎｍ）を示す。ρｐは表示用白色粒子の比重（ｇ／ｃｍ３）を示す。ρｓは分散媒の比重（ｇ／ｃｍ３）を示す。ｇは重力加速度（ｍ／ｓ２）を示す。） Formula (1) 400 ≧ 6 kT / (πd 3 (ρp−ρs) g) ≧ 30
Formula (1-2) 200 ≧ 6 kT / (πd 3 (ρp−ρs) g) ≧ 40
Formula (1-3) 100 ≧ 6 kT / (πd 3 (ρp−ρs) g) ≧ 40
(In the formulas (1) to (1-3), k represents the Boltzmann coefficient (J · K −1 ), T represents the absolute temperature 298 (K), and d represents the volume average particle diameter of the white particles for display ( .ρp showing a nm) is .ρs showing a specific gravity (g / cm 3) of the display white particles exhibit specific gravity of the dispersion medium (g / cm 3) shows the .g is a gravitational acceleration (m / s 2). )
　式（１）中、「６ｋＴ/（πｄ３（ρｐ－ρｓ）ｇ）」を３０以上にすると、表示用白色粒子の沈降を抑えられる一方、４００以下にすると、表示用白色粒子の沈降を抑えつつ、表示用白色粒子の白反射率を高くすることができる。 In the formula (1), when “6 kT / (πd 3 (ρp−ρs) g)” is set to 30 or more, the settling of the white particles for display can be suppressed. On the other hand, when set to 400 or less, the settling of the display white particles is suppressed. Meanwhile, the white reflectance of the display white particles can be increased.
　なお、表示用白色粒子が上記式（１）を満たすようにするには、例えば、表示用白色粒子の体積平均粒径、表示用白色粒子（つまり、粒子に含まれる白色顔料及び樹脂）の比重、分散媒の比重を調整することにより実現される。 In order to satisfy the above formula (1), for example, the volume average particle diameter of the display white particles and the specific gravity of the display white particles (that is, the white pigment and the resin contained in the particles) are used. This is realized by adjusting the specific gravity of the dispersion medium.
表示用白色粒子の組成
　表示用白色粒子は、白色顔料と樹脂とを含む。具体的には、表示用白色粒子は、例えば、顔料の表面を樹脂で被覆された構成を有する。 Composition of Display White Particles The display white particles include a white pigment and a resin. Specifically, the display white particles have a configuration in which the surface of the pigment is coated with a resin, for example.
　樹脂としては、特に制限はなく、例えば、表示用着色粒子で使用される樹脂が挙げられる。但し、表示用白色粒子の移動速度を十分遅くする、又は実質的に電界に応じて移動しなくするため、帯電性基量を低減した樹脂を用いることがよい。 The resin is not particularly limited, and examples thereof include resins used for display colored particles. However, in order to make the moving speed of the white particles for display sufficiently slow or not to move substantially according to the electric field, it is preferable to use a resin having a reduced chargeable group amount.
　白色顔料としては、例えば、酸化亜鉛、塩基性炭酸鉛、塩基性硫酸鉛、リトボン、硫化亜鉛、酸化チタン、酸化ジルコニア、酸化アンチモン、硫酸バリウムなど、任意の白色顔料が挙げられる。
　これらの中でも、白色顔料としては、表示用白色粒子の高反射率と沈降抑制とを両立させる観点から、酸化チタン、酸化ジルコニアが好ましく、酸化チタンが最も好ましい。
　ここで、酸化チタン粒子は、硫酸法、塩素法、気相法等いずれの方法により製造されたものでもよい。酸化チタンの結晶系は、アナターゼ型、ルチル型、又はブルカイト型いずれの結晶系のものでもよいが、ルチル型が好ましい。酸化チタン粒子は、光触媒性を抑制する観点から、酸化アルミニウム、水酸化アルミニウム、酸化ケイ素などを含有していることが好ましい。 Examples of the white pigment include arbitrary white pigments such as zinc oxide, basic lead carbonate, basic lead sulfate, ritbon, zinc sulfide, titanium oxide, zirconia oxide, antimony oxide, and barium sulfate.
Among these, as the white pigment, titanium oxide and zirconia oxide are preferable, and titanium oxide is most preferable from the viewpoint of achieving both high reflectance of display white particles and suppression of sedimentation.
Here, the titanium oxide particles may be produced by any method such as a sulfuric acid method, a chlorine method, or a gas phase method. The crystal system of titanium oxide may be an anatase type, a rutile type, or a brookite type, but the rutile type is preferred. The titanium oxide particles preferably contain aluminum oxide, aluminum hydroxide, silicon oxide or the like from the viewpoint of suppressing photocatalytic properties.
　白色顔料の体積平均粒径は、例えば、１ｎｍ以上５００ｎｍ以下であることがよく、１０ｎｍ以上２００ｎｍ以下が好ましく、２０ｎｍ以上１５０ｎｍ以下がより好ましい。
　白色顔料の体積平均粒径を上記範囲にすると、表示用白色粒子の白反射率を高くしつつ、沈降が抑制され易くなる点で有利である。 The volume average particle diameter of the white pigment is, for example, preferably from 1 nm to 500 nm, preferably from 10 nm to 200 nm, and more preferably from 20 nm to 150 nm.
When the volume average particle diameter of the white pigment is in the above range, it is advantageous in that sedimentation is easily suppressed while increasing the white reflectance of the white particles for display.
　表示用白色粒子における白色顔料の含有量（すなわち、白色顔料の質量/（白色顔料及び樹脂の総質量））は、３０質量％以上９０質量％以下であり、４０質量％以上７０質量％以下が好ましく、４０質量％以上６０質量％以下がより好ましい。
　白色顔料の含有量を３０質量％以上とすることにより、表示用白色粒子の白反射率を高くすることができる一方、９０質量％以下とすることにより、表示用白色粒子の白反射率を高くしつつ、沈降が抑制される。 The content of the white pigment in the white particles for display (that is, the mass of the white pigment / (total mass of the white pigment and the resin)) is 30% by mass to 90% by mass, and 40% by mass to 70% by mass. Preferably, 40 mass% or more and 60 mass% or less are more preferable.
The white reflectance of the white particles for display can be increased by setting the content of the white pigment to 30% by mass or more, while the white reflectance of the white particles for display is increased by setting the content to 90% by mass or less. However, sedimentation is suppressed.
表示用白色粒子の特性
　表示用白色粒子の体積平均粒径は、１００ｎｍ以上５００ｎｍ以下であり、１５０ｎｍ以上３００ｎｍ以下が好ましい。
　表示用白色粒子の体積平均粒径を１００ｎｍ以上とすることにより、表示用白色粒子の白反射率を高くすることができる一方、５００ｎｍ以下とすることにより、表示用白色粒子の白反射率を高くしつつ、沈降が抑制される。 Characteristics of Display White Particles The volume average particle size of the display white particles is from 100 nm to 500 nm, and preferably from 150 nm to 300 nm.
By setting the volume average particle size of the white particles for display to 100 nm or more, the white reflectance of the white particles for display can be increased. On the other hand, by setting the volume average particle size to 500 nm or less, the white reflectance of the white particles for display is increased. However, sedimentation is suppressed.
　表示用白色粒子の比重は、例えば、２．１ｇ／ｃｍ３以上４．３ｇ／ｃｍ３以下であることがよく、２．４ｇ／ｃｍ３以上３．６ｇ／ｃｍ３以下が好ましく、２．４ｇ／ｃｍ３以上３．３ｇ／ｃｍ３以下がより好ましい。
　表示用白色粒子の比重を上記範囲にすると、表示用白色粒子の白反射率を高くしつつ、沈降が抑制され易くなる点で有利である。 Specific gravity of the display white particles, for example, well, is preferably from 2.4 g / cm 3 or more 3.6 g / cm 3 or less 2.1 g / cm 3 or more 4.3 g / cm 3, 2.4 g / Cm 3 or more and 3.3 g / cm 3 or less is more preferable.
Setting the specific gravity of the display white particles in the above range is advantageous in that the white reflectance of the display white particles is increased and sedimentation is easily suppressed.
　表示用白色粒子は、表示用着色粒子による良好な表示コントラストを得る観点から、表示用着色粒子と逆極性の帯電特性を有するか、又は帯電量が低く、電解に応じて移動する移動速度が表示用着色粒子よりも十分低い粒子であることが好ましく、特に、実質的に、電界に応じて移動しない粒子であることがよい。
　具体的には、表示用白色粒子は、表示用着色粒子との電界に応じて移動する移動速度比（すなわち、表示用白色粒子の移動速度Ｖｗ／表示用着色粒子の移動速度Ｖｃ）が、０．２以下であることがよく、好ましくは０．１以下、より好ましくは０．０５以下である。
　この移動速度比を上記範囲にすると、表示用着色粒子による良好な表示コントラストが実現され易くなる点で有利である。また、表示用白色粒子の移動により表示用着色粒子の移動が阻害されることに起因する表示応答性の低下も抑制され易くなる点で有利である。
　なお、各粒子の移動速度は、後述する測定用セルを用いて測定した方法により測定された値である。 From the viewpoint of obtaining a good display contrast due to the colored particles for display, the white particles for display have a charge characteristic of opposite polarity to that of the colored particles for display, or have a low charge amount and display a moving speed that moves according to electrolysis. Particles that are sufficiently lower than the colored particles for use are preferable, and in particular, particles that do not substantially move in response to an electric field are preferable.
Specifically, the display white particles have a moving speed ratio (that is, the moving speed Vw of the white particles for display / the moving speed Vc of the colored particles for display) that moves according to the electric field with the colored particles for display is 0. .2 or less, preferably 0.1 or less, more preferably 0.05 or less.
When the moving speed ratio is in the above range, it is advantageous in that a good display contrast due to the colored particles for display is easily realized. Further, it is advantageous in that a decrease in display response due to the movement of the display colored particles being hindered by the movement of the display white particles is easily suppressed.
In addition, the moving speed of each particle | grain is the value measured by the method measured using the cell for a measurement mentioned later.
　なお、表示用白色粒子と表示用着色粒子との電界に応じて移動する移動速度比は、両粒子が表示用粒子分散液中に分散された状態において、表示用白色粒子の移動速度と表示用着色粒子のうち最も移動速度が遅い粒子の移動速度との比である。 Note that the moving speed ratio of the white particles for display and the colored particles for display moving according to the electric field is the same as the moving speed of the white particles for display and the display for both particles dispersed in the display particle dispersion. It is a ratio with the moving speed of the particles having the slowest moving speed among the colored particles.
　表示用白色粒子の濃度（画像表示装置の一対の基板間に封入された状態での表示用粒子分散液中の濃度）は、例えば、１体積％以上５０体積％以下であることがよく、好ましくは２体積％以上３０体積％以下である。
　表示用白色粒子の濃度を上記範囲にすると、白表示の反射率を高めつつ、表示用白色粒子の分散による分散媒の粘度上昇を抑え、表示用着色粒子による表示応答性の低下も抑制され易くなる点で有利である。
　なお、表示用白色粒子の濃度は、画像表示装置の一対の基板間に封入された状態での表示用粒子分散液中の濃度としても上記範囲であることがよい。また、表示用白色粒子の濃度は、画像表示装置の一対の基板間の距）により調整することが有効である。所望の色相を得るために、画像表示装置の一対の基板間の距離が大きくなるほど粒子濃度は少なくなり、当該距離が小さくほど粒子濃度は多くなる。 The concentration of the white particles for display (concentration in the display particle dispersion in a state enclosed between a pair of substrates of the image display device) is preferably, for example, 1% by volume to 50% by volume, and preferably Is 2% by volume or more and 30% by volume or less.
When the concentration of the white particles for display is within the above range, the increase in the viscosity of the dispersion medium due to the dispersion of the white particles for display is suppressed while increasing the reflectance of white display, and the decrease in display responsiveness due to the colored particles for display is easily suppressed. This is advantageous.
The concentration of the white particles for display is preferably in the above range as the concentration in the display particle dispersion in a state of being enclosed between a pair of substrates of the image display device. It is also effective to adjust the concentration of the display white particles by the distance between the pair of substrates of the image display device. In order to obtain a desired hue, the particle concentration decreases as the distance between the pair of substrates of the image display device increases, and the particle concentration increases as the distance decreases.
表示用白色粒子の製造方法
　表示用白色粒子は、表示用着色粒子の製造方法と同様に手法により製造することができる。 Method for Producing Display White Particles The display white particles can be produced by a method similar to the method for producing the display colored particles.
分散媒
　分散媒は、絶縁性液体であることが好ましい。ここで、「絶縁性」とは、体積固有抵抗値が１０１１Ωｃｍ以上であることを示している。
　絶縁性液体として具体的には、例えば、ヘキサン、シクロヘキサン、トルエン、キシレン、デカン、ヘキサデカン、ケロセン、パラフィン、イソパラフィン、シリコーンオイル、高純度石油、エチレングリコール、アルコール類、エーテル類、エステル類、ジメチルホルムアミド、ジメチルアセトアミド、ジメチルスルホキシド、１－メチル－２－ピロリドン、Ｎ－メチルホルムアミド、アセトニトリル、テトラヒドロフラン、プロピレンカーボネート、エチレンカーボネート、ベンジン、ジイソプロピルナフタレン、オリーブ油、トリクロロトリフルオロエタン、テトラクロロエタン、ジブロモテトラフルオロエタンなどや、それらの混合物が好適に挙げられる。 Dispersion medium The dispersion medium is preferably an insulating liquid. Here, “insulating” indicates that the volume resistivity value is 10 11 Ωcm or more.
Specific examples of the insulating liquid include hexane, cyclohexane, toluene, xylene, decane, hexadecane, kerosene, paraffin, isoparaffin, silicone oil, high-purity petroleum, ethylene glycol, alcohols, ethers, esters, dimethylformamide. , Dimethylacetamide, dimethylsulfoxide, 1-methyl-2-pyrrolidone, N-methylformamide, acetonitrile, tetrahydrofuran, propylene carbonate, ethylene carbonate, benzine, diisopropylnaphthalene, olive oil, trichlorotrifluoroethane, tetrachloroethane, dibromotetrafluoroethane, etc. Moreover, a mixture thereof is preferably mentioned.
　これらの中でも、分散媒としては、シリコーンオイルを適用することがよい。
　シリコーンオイルとして具体的には、シロキサン結合に炭化水素基が結合したシリコーンオイル（例えば、ジメチルシリコーンオイル、ジエチルシリコーンオイル、メチルエチルシリコーンオイル、メチルフェニルシリコーンオイル、ジフェニルシリコーンオイル等）が挙げられる。これらの中も、ジメチルシリコーンが特に好ましい。 Of these, silicone oil is preferably used as the dispersion medium.
Specific examples of the silicone oil include silicone oils in which a hydrocarbon group is bonded to a siloxane bond (for example, dimethyl silicone oil, diethyl silicone oil, methyl ethyl silicone oil, methyl phenyl silicone oil, diphenyl silicone oil, etc.). Among these, dimethyl silicone is particularly preferable.
分散媒の添加剤
　分散媒には、必要に応じて、酸、アルカリ、塩、分散安定剤、酸化防止もしくは紫外線吸収などを目的とした安定剤、抗菌剤、又は防腐剤などを添加してもよいが、上記で示した特定の体積固有抵抗値の範囲となるように添加することが好ましい。 Dispersion medium additives If necessary, the dispersion medium may contain acids, alkalis, salts, dispersion stabilizers, stabilizers for the purpose of preventing oxidation or ultraviolet absorption, antibacterial agents, preservatives, and the like. Although it is good, it is preferable to add so that it may become the range of the specific volume specific resistance value shown above.
　分散媒には、帯電制御剤として、陰イオン界面活性剤、陽イオン界面活性剤、両性界面活性剤、ノニオン界面活性剤、フッ素系界面活性剤、シリコーン系界面活性剤、金属石鹸、アルキルリン酸エステル類、コハク酸イミド類等を添加して使用してもよい。
　これら界面活性剤としては、以下のものが挙げられる。 For dispersion media, anionic surfactants, cationic surfactants, amphoteric surfactants, nonionic surfactants, fluorosurfactants, silicone surfactants, metal soaps, alkyl phosphates as charge control agents Esters and succinimides may be added and used.
Examples of these surfactants include the following.
　ノニオン系界面活性剤の例としては、
　ポリオキシエチレンノニルフェノールエーテル、ポリオキシエチレンオクチルフェニルエーテル等のポリオキシアルキレンアルキルフェノールエーテル類；
　ポリオキシエチレンセチルエーテル、ポリオキシプロピレンエーテル等のポリオキシアルキレンエーテル類；
　モノオールタイプのポリオキシアルキレングリコール、ジオールタイプのポリオキシアルキレングリコール、トリオールタイプのポリオキシアルキレングリコール等のグリコール類；
　オクチルフェノールエトキシレート等の第１級直鎖アルコールエトキシレート及び、第２級直鎖アルコールエトキシレート等のアルキルアルコールエーテル類；
　ポリオキシエチレンラウリルエステル等のポリオキシアルキレンアルキルエステル類；
　ソルビタンモノラウレイト、ソルビタンジラウレイト、ソルビタンセスキパルミテート等のソルビタン脂肪酸エステル類；
　ポリオキシエチレンソルビタンモノラウレイト、ポリオキシエチレンソルビタンジラウレイト、ポリオキシエチレンソルビタンセスキラウレイト、等のポリオキシエチレンソルビタンエステル類；
　飽和脂肪酸ステアリルエステル、不飽和脂肪酸ステアリルエステル、ステアリン酸ポリエチレングリコールエステル等の脂肪酸エステル類；
　ステアリン酸、オレイン酸等の脂肪酸類及び、これら脂肪酸のアミド化化合物類；
　ポリオキシエチレンアルキルアミン類、高級脂肪酸モノエタノールアミド類、高級脂肪酸ジエタノールアミド類、アミド化合物類及び、アルカノールアミド類が挙げられる。 Examples of nonionic surfactants include
Polyoxyalkylene alkylphenol ethers such as polyoxyethylene nonylphenol ether and polyoxyethylene octylphenyl ether;
Polyoxyalkylene ethers such as polyoxyethylene cetyl ether and polyoxypropylene ether;
Glycols such as monool type polyoxyalkylene glycol, diol type polyoxyalkylene glycol, triol type polyoxyalkylene glycol;
Alkyl alcohol ethers such as primary linear alcohol ethoxylates such as octylphenol ethoxylate and secondary linear alcohol ethoxylates;
Polyoxyalkylene alkyl esters such as polyoxyethylene lauryl ester;
Sorbitan fatty acid esters such as sorbitan monolaurate, sorbitan dilaurate, sorbitan sesquipalmitate;
Polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan dilaurate, polyoxyethylene sorbitan sesquilaurate, and other polyoxyethylene sorbitan esters;
Fatty acid esters such as saturated fatty acid stearyl ester, unsaturated fatty acid stearyl ester, and stearic acid polyethylene glycol ester;
Fatty acids such as stearic acid and oleic acid, and amidated compounds of these fatty acids;
Examples include polyoxyethylene alkylamines, higher fatty acid monoethanolamides, higher fatty acid diethanolamides, amide compounds, and alkanolamides.
　アニオン系界面活性剤の例としては、
　ポリカルボン酸型高分子活性剤、ロジン石鹸等のカルボン酸塩類；ヒマシ油硫酸エステル塩、ラウリルアルコールの硫酸エステルＮａ塩、ラウリルアルコールの硫酸エステルアミン塩、高級アルコール硫酸エステルＮａ塩等のアルコール系硫酸エステル塩類及び、ラウリルアルコールエーテルの硫酸エステルアミン塩、ラウリルアルコールエーテルの硫酸エステルＮａ塩、合成高級アルコールエーテルの硫酸エステルアミン塩、合成高級アルコールエーテルの硫酸エステルＮａ塩、アルキルポリエーテル硫酸エステルアミン塩、アルキルポリエーテル硫酸エステルＮａ塩、天然アルコールＥＯ（エチレンオキシド）付加体系硫酸エステルアミン塩、天然アルコールＥＯ（エチレンオキシド）付加体系硫酸エステルＮａ塩、合成アルコールＥＯ（エチレンオキシド）付加体系硫酸エステルアミン塩、合成アルコールＥＯ（エチレンオキシド）付加体系硫酸エステルＮａ塩、アルキルフェノールＥＯ（エチレンオキシド）付加体系硫酸エステルアミン塩、アルキルフェノールＥＯ（エチレンオキシド）付加体系硫酸エステルＮａ塩、ポリオキシエチレンノニルフェニルエーテル硫酸エステルアミン塩、ポリオキシエチレンノニルフェニルエーテル硫酸エステルＮａ塩、ポリオキシエチレン多環フェニルエーテル硫酸エステルアミン塩、ポリオキシエチレン多環フェニルエーテル硫酸エステルＮａ塩等の硫酸エステル塩類；
　各種アルキルアリルスルホン酸アミン塩、各種アルキルアリルスルホン酸Ｎａ塩、ナフタレンスルホン酸アミン塩、ナフタレンスルホン酸Ｎａ塩、各種アルキルベンゼンスルホン酸アミン塩、各種アルキルベンゼンスルホン酸Ｎａ塩、ナフタレンスルホン酸縮合物、ナフタレンスルホン酸ホルマリン縮合物等のスルホン酸塩類；
　ポリオキシエチレンノニルフェニルエーテルスルホン酸アミン塩、ポリオキシエチレンノニルフェニルエーテルスルホン酸Ｎａ塩などのポリオキシアルキレン系スルホン酸塩類が挙げられる。 Examples of anionic surfactants include
Carboxylates such as polycarboxylic acid type polymer activators and rosin soaps; alcoholic sulfuric acid such as castor oil sulfate ester salt, lauryl alcohol sulfate ester Na salt, lauryl alcohol sulfate ester amine salt, higher alcohol sulfate ester Na salt Ester salts, sulfate amine amine of lauryl alcohol ether, sulfate ester Na salt of lauryl alcohol ether, sulfate ester amine salt of synthetic higher alcohol ether, sulfate ester Na salt of synthetic higher alcohol ether, alkyl polyether sulfate amine salt, Alkyl polyether sulfate sodium salt, natural alcohol EO (ethylene oxide) addition system sulfate amine salt, natural alcohol EO (ethylene oxide) addition system sulfate sodium salt, synthetic alcohol EO Ethylene oxide) addition system sulfate ester amine salt, synthetic alcohol EO (ethylene oxide) addition system sulfate ester Na salt, alkylphenol EO (ethylene oxide) addition system sulfate ester amine salt, alkylphenol EO (ethylene oxide) addition system sulfate ester Na salt, polyoxyethylene nonyl Sulfate esters such as phenyl ether sulfate amine salt, polyoxyethylene nonylphenyl ether sulfate Na salt, polyoxyethylene polycyclic phenyl ether sulfate amine salt, polyoxyethylene polycyclic phenyl ether sulfate Na salt;
Various alkyl allyl sulfonic acid amine salts, various alkyl allyl sulfonic acid Na salts, naphthalene sulfonic acid amine salts, naphthalene sulfonic acid Na salts, various alkyl benzene sulfonic acid amine salts, various alkyl benzene sulfonic acid Na salts, naphthalene sulfonic acid condensates, naphthalene sulfone Sulfonates such as acid formalin condensates;
Examples thereof include polyoxyalkylene sulfonates such as polyoxyethylene nonylphenyl ether sulfonate amine salt and polyoxyethylene nonylphenyl ether sulfonate Na salt.
　カチオン系界面活性剤の例としては、
　アルキルトリメチルアミン系４級アンモニウム塩類；テトラメチルアミン系塩、テトラブチルアミン塩等の４級アンモニウム塩類；（ＲＮＨ３）（ＣＨ３ＣＯＯ）〔Ｒ＝ステアリル、セチル、ラウリル、オレイル、ドデシル、テトラデシル、ヘキサデシル、又はリノレイル等〕で表される酢酸塩類；ラウリルジメチルベンジルアンモニウム塩（ハロゲン塩又はアミン塩等）、ステアリルジメチルベンジルアンモニウム塩（ハロゲン塩又はアミン塩等）、ドデシルジメチルベンジルアンモニウム塩（ハロゲン塩又はアミン塩等）等のベンジルアミン系４級アンモニウム塩類；
　Ｒ（ＣＨ３）Ｎ（Ｃ２Ｈ４Ｏ）ｍＨ（Ｃ２Ｈ４Ｏ）ｎ・Ｘ〔Ｒ＝ステアリル、セチル、ラウリル、オレイル、ドデシル、ヤシ油、大豆油、又は牛脂等；Ｘ＝ハロゲン又はアミン等〕で表されるポリオキシアルキレン系４級アンモニウム塩類が挙げられる。 Examples of cationic surfactants include
Alkyltrimethylamine quaternary ammonium salts; quaternary ammonium salts such as tetramethylamine salts and tetrabutylamine salts; (RNH 3 ) (CH 3 COO) [R = stearyl, cetyl, lauryl, oleyl, dodecyl, tetradecyl, hexadecyl, Or linoleyl, etc.]; lauryldimethylbenzylammonium salt (halogen salt or amine salt), stearyldimethylbenzylammonium salt (halogen salt or amine salt), dodecyldimethylbenzylammonium salt (halogen salt or amine salt) Benzylamine-based quaternary ammonium salts such as
R (CH 3 ) N (C 2 H 4 O) m H (C 2 H 4 O) n × X [R = stearyl, cetyl, lauryl, oleyl, dodecyl, coconut oil, soybean oil, beef tallow, etc .; X = Polyoxyalkylene-based quaternary ammonium salts represented by [halogen or amine].
　両性系界面活性剤の例としては、各種ベタイン型界面活性剤等が挙げられる。 Examples of amphoteric surfactants include various betaine surfactants.
　表示用粒子分散液におけるこれら帯電制御剤の含有量（複数種使用する場合は総含有量）は、例えば、全粒子（すなわち、表示用着色粒子及び表示用白色粒子）の総固形分に対して０．０１質量％以上であることがよく、好ましくは２０質量％以下、より好ましくは０．０５質量％以上１０質量％以下である。
　帯電制御剤の含有量を０．０１質量％以上にすると、希望とする帯電制御効果が十分発揮され易くなる点で有利であり、２０質量％以下にすると、分散媒の過度な電導度の上昇が抑制され易くなる点で有利である。 The content of these charge control agents in the display particle dispersion (the total content when multiple types are used) is, for example, based on the total solid content of all the particles (that is, the display colored particles and the display white particles). It is good that it is 0.01 mass% or more, Preferably it is 20 mass% or less, More preferably, it is 0.05 mass% or more and 10 mass% or less.
When the content of the charge control agent is 0.01% by mass or more, it is advantageous in that the desired charge control effect is sufficiently exhibited, and when it is 20% by mass or less, an excessive increase in conductivity of the dispersion medium is achieved. Is advantageous in that it is easily suppressed.
　分散媒は、高分子が添加されていてもよい。この高分子としては、高分子ゲル、高分子ポリマー等であることも好ましい。 The dispersion medium may be added with a polymer. The polymer is preferably a polymer gel or a polymer.
分散媒の特性
　分散媒の比重は、例えば、温度２５℃の環境下において、０．６ｇ／ｃｍ３以上１．２ｇ／ｃｍ３以下であることがよく、０．７ｇ／ｃｍ３以上１．１ｇ／ｃｍ３以下が好ましく、０．７ｇ／ｃｍ３以上１．０ｇ／ｃｍ３以下がより好ましい。
　表示用白色粒子の比重を上記範囲にすると、表示用白色粒子の沈降が抑制され易くなる点で有利である。 Characteristics of Dispersion Medium The specific gravity of the dispersion medium is, for example, preferably 0.6 g / cm 3 or more and 1.2 g / cm 3 or less, and 0.7 g / cm 3 or more and 1.1 g in an environment at a temperature of 25 ° C. / Cm 3 or less is preferable, and 0.7 g / cm 3 or more and 1.0 g / cm 3 or less is more preferable.
Setting the specific gravity of the display white particles in the above range is advantageous in that the precipitation of the display white particles is easily suppressed.
　分散媒の粘度は、例えば、温度２０℃の環境下において、０．１ｍＰａ・ｓ以上１００ｍＰａ・ｓ以下であることよく、０．１ｍＰａ・ｓ以上５０ｍＰａ・ｓ以下であることが望ましく、０．１ｍＰａ・ｓ以上２０ｍＰａ・ｓ以下であることがより好ましい。
　特に、分散媒の粘度は、５ｍＰａ・ｓ以下であることがよい。分散媒の粘度を５ｍＰａ・ｓ以下にすると、表示用着色粒子の表示応答性も向上し、５ｍＰａ・ｓ以下であっても、表示用白色粒子が上記特性を持つことから、その沈降が抑制され易くなる点で有利である。
　なお、分散媒の粘度の調整は、例えば、分散媒の分子量、構造、組成等を調整することによって行うことができる。 The viscosity of the dispersion medium is, for example, preferably from 0.1 mPa · s to 100 mPa · s, preferably from 0.1 mPa · s to 50 mPa · s in an environment of a temperature of 20 ° C. More preferably, it is s or more and 20 mPa · s or less.
In particular, the viscosity of the dispersion medium is preferably 5 mPa · s or less. When the viscosity of the dispersion medium is 5 mPa · s or less, the display responsiveness of the colored particles for display is improved, and even when the viscosity is 5 mPa · s or less, the white particles for display have the above characteristics, so that the sedimentation is suppressed. It is advantageous in that it becomes easy.
The viscosity of the dispersion medium can be adjusted, for example, by adjusting the molecular weight, structure, composition, etc. of the dispersion medium.
表示用粒子分散液のその他態様
　本発明の表示用分散液は、カプセル壁で内包されていてもよい。つまり、カプセル粒子中に、表示用白色粒子、表示用着色粒子、及び分散媒が含有されていてもよい。 Other Embodiments of Display Particle Dispersion Liquid The display dispersion liquid of the present invention may be encapsulated by a capsule wall. That is, the capsule particles may contain display white particles, display colored particles, and a dispersion medium.
　カプセル壁を構成する主たる材料は、ゼラチン、ホルマリン樹脂、ウレタン樹脂を好ましく用いることができるが、ゼラチンであることが最も好ましい。
　ゼラチンとしては、コラーゲンからの誘導過程で石灰などによる処理を伴う所謂アルカリ処理ゼラチン、同じく塩酸などによる処理を伴う所謂酸処理ゼラチン、加水分解酵素などの処理を伴う酸素処理ゼラチン、ゼラチン分子中に含まれる官能基としてのアミノ基、イミノ基、ヒドロキシル基またはカルボキシル基をそれらと反応しうる基を一個持った試薬で処理、改質した例、例えばフタル化ゼラチン、コハク化ゼラチン、トリメトリト化ゼラチン等の所謂ゼラチン誘導体、変性ゼラチン等、例えば特開昭６２－２１５２７２号２２２頁左下欄６行目から２２５頁左上欄末行目などに記載される当業界内で一般に用いられているものが挙げられる。 As the main material constituting the capsule wall, gelatin, formalin resin and urethane resin can be preferably used, but gelatin is most preferable.
Gelatin includes so-called alkali-treated gelatin with treatment with lime in the process of induction from collagen, so-called acid-treated gelatin with treatment with hydrochloric acid, oxygen-treated gelatin with treatment with hydrolase, etc., contained in gelatin molecules Examples of treated and modified amino group, imino group, hydroxyl group or carboxyl group as a functional group with a reagent having one group capable of reacting with them, such as phthalated gelatin, succinylated gelatin, trimethrylated gelatin, etc. Examples of so-called gelatin derivatives and modified gelatin include those commonly used in the industry described in JP-A-62-215272, page 222, lower left column, line 6 to page 225, upper left column.
　ゼラチン等の高分子電解質をカプセル壁に用いた場合に使用される架橋剤としては、例えば、グリオキサール、グルタルアルデヒド、スクシンアルデヒド、ジカルボン酸（例えば例えば、シュウ酸、コハク酸、フマル酸、マレイン酸、リンゴ酸、グルタル酸、アジピン酸、２，３－Ｏ－イソプロピリデン酒石酸等）、二酸塩化物（例えばスクシニルクロリド、フマリルクロリド、グルタリルクロリド、アジポイルクロリド等）、トリカルボン酸（例えばクエン酸、１，２，３－プロパントリカルボン酸、ヘミメリット酸、トリメリット酸、トリメシン酸等）が挙げられる。
　架橋剤としては、例えば、特表２００５－５２２３１３に、酵素（トランスグルタミナーゼなど）による架橋反応を用いることが記載されており、この様な架橋反応を生じさせる酵素も挙げられる。
　架橋剤としては、例えば、特表２００９－５３１５３２記載に記載された、エポキシ樹脂、２－ヒドロキシアルキルアミド類、テトラメトキシメチルグリセリル、ポリアジリジン、ポリカルボジイミド、イソシアネート類、ブロック化イソシアネート類、乾性油（例えばトリグリセリド類、グリセロールエポキシエステル類、脂肪酸のトリエステル類等）、脂肪族アミン類、フェノール類、ポリイソシアネート類、アミン類、尿素、カルボン酸類、アルコール類、ポリエーテル類、尿素ホルムアルデヒド、メラミン類、アルデヒド類、多価アニオン類の塩も挙げられる。
　架橋剤は、その架橋反応を促進する触媒と併用してもよく、触媒としては、特表２００９－５３１５３２記載に記載された、アルコール類、フェノール類、弱酸類、アミン類、金属塩類、ウレタン類、キレート類、有機金属材料、光開始剤、フリーラジカル開始剤、強酸類のオニウム塩類が挙げられる。 Examples of the crosslinking agent used when a polymer electrolyte such as gelatin is used for the capsule wall include glyoxal, glutaraldehyde, succinaldehyde, and dicarboxylic acid (for example, oxalic acid, succinic acid, fumaric acid, maleic acid). , Malic acid, glutaric acid, adipic acid, 2,3-O-isopropylidene tartaric acid, etc.), diacid chlorides (eg succinyl chloride, fumaryl chloride, glutaryl chloride, adipoyl chloride etc.), tricarboxylic acids (eg Citric acid, 1,2,3-propanetricarboxylic acid, hemimellitic acid, trimellitic acid, trimesic acid and the like.
As the cross-linking agent, for example, JP 2005-522313 describes the use of a cross-linking reaction by an enzyme (transglutaminase or the like), and examples thereof include an enzyme that causes such a cross-linking reaction.
Examples of the crosslinking agent include epoxy resins, 2-hydroxyalkylamides, tetramethoxymethyl glyceryl, polyaziridine, polycarbodiimide, isocyanates, blocked isocyanates, drying oils (described in JP-T-2009-531532) For example, triglycerides, glycerol epoxy esters, fatty acid triesters, etc.), aliphatic amines, phenols, polyisocyanates, amines, urea, carboxylic acids, alcohols, polyethers, urea formaldehyde, melamines, Examples include aldehydes and salts of polyvalent anions.
The crosslinking agent may be used in combination with a catalyst that promotes the crosslinking reaction. Examples of the catalyst include alcohols, phenols, weak acids, amines, metal salts, urethanes described in JP-T-2009-531532. Chelates, organometallic materials, photoinitiators, free radical initiators, onium salts of strong acids.
　なお、架橋剤及び／又はその触媒を水相中に添加して用いるか、あるいは内相油相中に添加して有機溶媒中から架橋反応を起こさせるかについては、適宜選択することができる。 It should be noted that whether the crosslinking agent and / or catalyst thereof is added to the aqueous phase and used, or whether the crosslinking agent and the catalyst are added to the inner phase oil phase to cause the crosslinking reaction in the organic solvent can be appropriately selected.
　ここで、カプセル壁を形成のための乳化分散工程において用いられる乳化分散装置として、高速撹拌機（ディゾルバー）、ホモジナイザー、インラインミキサー等の通常の乳化手段が挙げられるが、特に、マイクロリアクター又はマイクロミキサーを利用することが好適である。 Here, examples of the emulsifying and dispersing apparatus used in the emulsifying and dispersing step for forming the capsule wall include ordinary emulsifying means such as a high-speed stirrer (dissolver), a homogenizer, and an in-line mixer, and in particular, a microreactor or a micromixer. Is preferably used.
　通常の乳化手段は、乳化に必要な剪断力の働く領域が、乳化翼の極く近傍に限られているため、剪断力が乳化翼の遠近で不均一になり、分散液滴の粒子径分布が広くなる問題があった。また超音波分散装置は実験室スケールないし小規模での工業生産スケールで用いられる場面があるが、高度の生産性を訴求した生産システムにおいては生産量、コスト、及び粒子径分布の制御などに課題が残っている。 The normal emulsification means has a region where shear force necessary for emulsification is limited to the vicinity of the emulsifying blade, so the shearing force becomes uneven near the emulsifying blade, and the particle size distribution of the dispersed droplets There was a problem of widening. Ultrasonic dispersers are used in laboratories or small-scale industrial production scales, but in production systems that demand high productivity, there are issues in controlling production volume, cost, and particle size distribution. Remains.
　この点に関して、特許第２６３０５０１号明細書には、前記のような乳化手段を用いることにより生ずる粒径分布の問題を解決する乳化方法として、いわゆるシリンドリカルミルを用いる乳化方法が開示されている。この乳化方法は、固定した外側円筒の中で内側円筒を回転させて、内側円筒と外側円筒との間隙に分散媒と分散液との混合液を通して乳濁液を得る乳化方法であり、混合液を外側円筒の一端部の側面より円周に沿って接線方向から供給し、混合液が内外円筒間の間隙を回転しつつ移動する間、内側円筒の長さにわたって均一な剪断力を働かせるようにして充分に乳化させる方法である。この乳化方法によると、極めて狭い粒径分布を有する乳化液が得られるが、この方法で得られる液滴粒径の大きさは、内側円筒と外側円筒との間隙の大きさに依存するので、ある限度以下の粒径の乳化粒子を得にくく、この方法で得られる液滴の粒径は、通常１０μｍ程度が限度で、数μｍ以下の粒径の液滴を得ることはでき難いのが現状である。 In this regard, Japanese Patent No. 2630501 discloses an emulsification method using a so-called cylindrical mill as an emulsification method for solving the problem of the particle size distribution caused by using the emulsification means as described above. This emulsification method is an emulsification method in which an inner cylinder is rotated in a fixed outer cylinder, and an emulsion is obtained by passing a mixture of a dispersion medium and a dispersion into a gap between the inner cylinder and the outer cylinder. Is supplied from the side of one end of the outer cylinder from the tangential direction along the circumference so that a uniform shear force is applied over the length of the inner cylinder while the mixture moves while rotating through the gap between the inner and outer cylinders. And fully emulsified. According to this emulsification method, an emulsified liquid having an extremely narrow particle size distribution can be obtained, but the size of the droplet particle size obtained by this method depends on the size of the gap between the inner cylinder and the outer cylinder. It is difficult to obtain emulsified particles having a particle size below a certain limit, and the particle size of droplets obtained by this method is usually about 10 μm, and it is difficult to obtain droplets with a particle size of several μm or less. It is.
　これに対して、いわゆるマイクロリアクターと称される装置が、ファインケミカル分野、バイオケミカル分野等で用いられるようになり、最近大きな発展を遂げている（W.Ehrfeld, V.Hessel, H.Lowe, "Microreactor", 1Ed.(2000), WILEY-VCHを参照）。
　マイクロリアクターは、マイクロスケールの複数の流路（チャンネル）を有する反応装置を一般に総称するものであり、たとえば二種類の液体が異なる流路を通る間に、極めて薄い液膜として互いに接触するもので、その間に層の界面を通して物質移動が行われ、反応が生ずる。
　マイクロリアクターは、化学反応だけでなく、２種以上の液体を混合したりあるいは分離を行うことにも利用される。特に、混合のために用いるマイクロリアクターはマイクロミキサーと称され、混合すべき互いに異なる液体の液膜を積層構造に作り、これを狭い通路を通すことにより相互に混合するものであり、例えば、液体として油相液と水相液を用いることにより乳化分散液を調製することができる。ＷＯ００／６２９１３号公報には、このようなマイクロリアクターを用いて分散を行わせる分散機（マイクロミキサー）が提案されている。この分散機は、液体Ａおよび液体Ｂの液流をそれぞれ、マイクロスケールの流路（チャンネル）に別々に通すことによって、空間的に分割された液層（液膜）に分割し、次いで分割した液流を結合し狭い通路を通すことにより液体Ａまたは液体Ｂを細かい液滴に分散させ、その際、機械的なオシレーターを用いて液滴化を促進する方法である。 In contrast, so-called microreactors have been used in the fields of fine chemicals, biochemicals, etc., and have recently been greatly developed (W. Ehrfeld, V. Hessel, H. Lowe, " Microreactor ", 1Ed. (2000), WILEY-VCH).
A microreactor is a general term for reaction devices having a plurality of microscale flow paths (channels). For example, two types of liquids contact each other as extremely thin liquid films while passing through different flow paths. In the meantime, mass transfer takes place through the interface of the layers and a reaction takes place.
The microreactor is used not only for a chemical reaction but also for mixing or separating two or more liquids. In particular, a microreactor used for mixing is called a micromixer, which forms liquid films of different liquids to be mixed in a laminated structure, and mixes them by passing through narrow passages. An emulsified dispersion can be prepared by using an oil phase liquid and an aqueous phase liquid. WO 00/62913 proposes a disperser (micromixer) that performs dispersion using such a microreactor. This disperser is divided into spatially divided liquid layers (liquid films) by separately passing the liquid flows of liquid A and liquid B through micro-scale flow paths (channels), and then divided. In this method, the liquid A or the liquid B is dispersed into fine droplets by combining the liquid flow and passing through a narrow passage, and at that time, droplet formation is promoted using a mechanical oscillator.
　このようなマイクロチャンネルを有するマイクロリアクター又はマイクロミキサーを用いた乳化分散によりカプセル壁を作製する技術については特開２００２－２８２６７８及び特開２００２－２８２６７９に詳述されており、本発明ではこれを利用することがよい。 Techniques for producing capsule walls by emulsification and dispersion using a microreactor or micromixer having such a microchannel are described in detail in JP-A Nos. 2002-282678 and 2002-282679, and the present invention uses this technique. It is good to do.
画像表示装置
　本実施形態に係る画像表示装置は、少なくとも一方が透光性を有する一対の基板と、一対の基板間に封入された表示用粒子分散液と、表示用着色粒子を移動させる強度の電界を一対の基板間に付与する電界発生手段と、を備える。
　そして、表示用粒子分散液として、上記本発明の実施形態に係る表示用粒子分散液が適用される。 Image display device The image display device according to the present embodiment has a pair of substrates, at least one of which has translucency, a display particle dispersion encapsulated between the pair of substrates, and a strength for moving the display colored particles. Electric field generating means for applying an electric field between the pair of substrates.
The display particle dispersion according to the embodiment of the present invention is applied as the display particle dispersion.
　以下、図面を参照しつつ、本発明の一実施形態に係る画像表示装置について説明する。
　図１は、本発明の実施形態に係る画像表示装置を示す概略構成図である。
　なお、本発明の一実施形態に係る画像表示装置１０は、その表示媒体１２の着色粒子群３４と白色粒子群３６と分散媒５０とを含む粒子分散液として、上記本実施形態に係る表示用粒子分散液を適用する形態である。つまり、着色粒子群３４として表示用着色粒子の群を適用し、白色粒子群３６として表示用白色粒子を適用した形態である Hereinafter, an image display apparatus according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram illustrating an image display apparatus according to an embodiment of the present invention.
The image display device 10 according to an embodiment of the present invention uses the display medium according to the present embodiment as a particle dispersion liquid including the colored particle group 34, the white particle group 36, and the dispersion medium 50 of the display medium 12. In this mode, a particle dispersion is applied. In other words, a group of display colored particles is applied as the colored particle group 34, and display white particles are applied as the white particle group 36.
　本実施形態に係る画像表示装置１０は、図１に示すように、表示媒体１２と、電圧印加部１６（電界発生手段の一例）と、制御部１８と、を含む。 The image display apparatus 10 according to the present embodiment includes a display medium 12, a voltage application unit 16 (an example of an electric field generating unit), and a control unit 18, as shown in FIG.
表示媒体
　表示媒体１２は、図１に示すように、表示面とされる表示基板２０と、表示基板２０に間隙をもって対向する背面基板２２と、これらの基板間を所定間隔に保持すると共に、表示基板２０と背面基板２２との間を複数のセルに区画する間隙部材２４と、を含む。
　ここで、上記セルとは、表示基板２０と、背面基板２２と、間隙部材２４と、によって囲まれた領域を示している。このセル中には、着色粒子群３４と、白色粒子群３６と、それら粒子群を分散する分散媒５０と、が封入されている。着色粒子群３４及び白色粒子群３６はこの分散媒５０中に分散され、着色粒子群３４はセル内に形成された電界強度に応じて表示基板２０と背面基板２２との間を移動する。各間隙部材２４の、セルの内側の表面には表面層２５が設けられている。 Display Medium As shown in FIG. 1, the display medium 12 holds a display substrate 20 as a display surface, a back substrate 22 facing the display substrate 20 with a gap, and a gap between these substrates at a predetermined interval. And a gap member 24 that partitions the substrate 20 and the back substrate 22 into a plurality of cells.
Here, the cell refers to a region surrounded by the display substrate 20, the back substrate 22, and the gap member 24. In this cell, a colored particle group 34, a white particle group 36, and a dispersion medium 50 for dispersing these particle groups are enclosed. The colored particle group 34 and the white particle group 36 are dispersed in the dispersion medium 50, and the colored particle group 34 moves between the display substrate 20 and the back substrate 22 in accordance with the electric field strength formed in the cell. A surface layer 25 is provided on the inner surface of each gap member 24.
　なお、この表示媒体１２に画像を表示したときの各画素に対応するように間隙部材２４を設け、各画素に対応するようにセルを形成することで、表示媒体１２を、画素毎の色表示が可能となるように構成してもよい。
　そして、表示媒体１２の分散媒５０中には、互いに色が異なる複数種類の着色粒子群３４が分散されている。複数種類の着色粒子群３４は、基板間を電気泳動可能な粒子であり、電界に応じて移動するために必要な電圧の絶対値が各色の粒子群でそれぞれ異なる。 It is to be noted that the gap member 24 is provided so as to correspond to each pixel when an image is displayed on the display medium 12, and cells are formed so as to correspond to each pixel, whereby the display medium 12 displays the color for each pixel. May be configured to be possible.
A plurality of types of colored particle groups 34 having different colors are dispersed in the dispersion medium 50 of the display medium 12. The plurality of types of colored particle groups 34 are particles that can be electrophoresed between the substrates, and the absolute value of the voltage required to move in accordance with the electric field is different for each color particle group.
表示基板及び背面基板
　表示基板２０は、支持基板３８上に、表面電極４０及び表面層４２を順に積層した構成を有している。背面基板２２は、支持基板４４上に、背面電極４６及び表面層４８を順に積層した構成となっている。 Display Substrate and Back Substrate The display substrate 20 has a configuration in which a surface electrode 40 and a surface layer 42 are sequentially laminated on a support substrate 38. The back substrate 22 has a structure in which a back electrode 46 and a surface layer 48 are sequentially laminated on a support substrate 44.
　支持基板３８及び支持基板４４の材料の例としては、ガラスや、プラスチック、例えば、ポリカーボネート樹脂、アクリル樹脂、ポリイミド樹脂、ポリエステル樹脂、エポキシ樹脂、ポリエーテルサルフォン樹脂等が挙げられる。 Examples of the material of the support substrate 38 and the support substrate 44 include glass and plastic, for example, polycarbonate resin, acrylic resin, polyimide resin, polyester resin, epoxy resin, polyether sulfone resin, and the like.
　表面電極４０及び背面電極４６の材料の例としては、インジウム、スズ、カドミウム、アンチモン等の酸化物、ＩＴＯ等の複合酸化物、金、銀、銅、ニッケル等の金属、ポリピロールやポリチオフェン等の有機材料等が挙げられる。表面電極４０及び背面電極４６は、これらの単層膜、混合膜又は複合膜のいずれであってもよく、例えば、蒸着法、スパッタリング法、塗布法等で形成される。 Examples of materials for the front electrode 40 and the back electrode 46 include oxides such as indium, tin, cadmium and antimony, composite oxides such as ITO, metals such as gold, silver, copper and nickel, organics such as polypyrrole and polythiophene. Materials and the like. The front electrode 40 and the back electrode 46 may be any of these single layer films, mixed films, or composite films, and are formed by, for example, vapor deposition, sputtering, coating, or the like.
　表面電極４０及び背面電極４６の膜厚は、所望の導電率が得られるように適宜調整されるが、一般には、１０ｎｍ以上１μｍ以下である。
　背面電極４６及び表面電極４０は、従来の液晶表示素子あるいはプリント基板のエッチング等従来公知の手段により、所望のパターン、例えば、マトリックス状、又はパッシブマトリックス駆動を可能とするストライプ状に形成される。 The film thicknesses of the surface electrode 40 and the back electrode 46 are adjusted as appropriate so as to obtain a desired conductivity, but are generally 10 nm or more and 1 μm or less.
The back electrode 46 and the front electrode 40 are formed in a desired pattern, for example, a matrix shape or a stripe shape that enables passive matrix driving, by a conventionally known means such as etching of a conventional liquid crystal display element or a printed board.
　表面電極４０を支持基板３８に埋め込んでもよい。同様に、背面電極４６を支持基板４４に埋め込んでもよい。背面電極４６及び表面電極４０各々を表示基板２０及び背面基板２２と分離させ、表示媒体１２の外部に配置してもよい。 The surface electrode 40 may be embedded in the support substrate 38. Similarly, the back electrode 46 may be embedded in the support substrate 44. The back electrode 46 and the surface electrode 40 may be separated from the display substrate 20 and the back substrate 22 and disposed outside the display medium 12.
　なお、上記では、表示基板２０と背面基板２２の双方に電極（表面電極４０及び背面電極４６）を備える場合を説明したが、何れか一方にのみ設けるようにしてもよい。
　また、アクティブマトリックス駆動を可能にするために、支持基板３８及び支持基板４４は、画素毎にＴＦＴ（薄膜トランジスタ）、ＴＦＤ（薄膜ダイオード）、ＭＩＭ（Ｍｅｔａｌ－Ｉｎｓｕｌａｔｏｒ－Ｍｅｔａｌ）素子、バリスタなどの能動素子を備えていてもよい。配線の積層化及び部品実装が容易であることから、能動素子は表示基板２０ではなく背面基板２２に形成することが好ましい。 In the above description, the case where both the display substrate 20 and the back substrate 22 are provided with the electrodes (the front electrode 40 and the back electrode 46) has been described.
In order to enable active matrix driving, the support substrate 38 and the support substrate 44 are provided with active elements such as TFT (Thin Film Transistor), TFD (Thin Film Diode), MIM (Metal-Insulator-Metal) element, and varistor for each pixel. May be provided. The active elements are preferably formed not on the display substrate 20 but on the back substrate 22 because wiring can be easily stacked and components can be easily mounted.
　表面電極４０及び背面電極４６が、各々支持基板３８及び支持基板４４上に形成されている場合、表面電極４０及び背面電極４６の破損や、着色粒子群３４の各粒子の固着を招く電極間のリークの発生を防止するため、必要に応じて表面電極４０及び背面電極４６各々上に誘電体膜としての表面層４２及び表面層４８を形成することが好ましい。
　なお、本実施形態では、表示基板２０と背面基板２２の対向面の双方に表面層（表面層４２及び表面層４８各々）が設けられている場合を説明するが、表示基板２０と背面基板２２の対向面の何れか一方にのみ設けられた構成であってもよい。また、これらの表面層は異なる材質で作製されていてもよい。 When the surface electrode 40 and the back electrode 46 are formed on the support substrate 38 and the support substrate 44, respectively, the electrodes between the electrodes that cause the damage of the surface electrode 40 and the back electrode 46 and the fixation of the particles of the colored particle group 34 are formed. In order to prevent the occurrence of leakage, it is preferable to form the surface layer 42 and the surface layer 48 as dielectric films on the surface electrode 40 and the back electrode 46, respectively, as necessary.
In the present embodiment, the case where the surface layers (each of the surface layer 42 and the surface layer 48) are provided on both the opposing surfaces of the display substrate 20 and the back substrate 22 will be described. However, the display substrate 20 and the back substrate 22 are described. The structure provided only in either one of these opposing surfaces may be sufficient. These surface layers may be made of different materials.
　表面層４２及び表面層４８の材料の例としては、ポリエチレン、ポリプロピレン等のポリオレフィン類、ポリカーボネート、ポリエステル、ポリスチレン、ポリイミド、ポリウレタン、ポリアミド、ポリメチルメタクリレート、共重合ナイロン、エポキシ樹脂、紫外線硬化アクリル樹脂、シリコーン樹脂、フッ素樹脂等が挙げられる。 Examples of the material of the surface layer 42 and the surface layer 48 include polyolefins such as polyethylene and polypropylene, polycarbonate, polyester, polystyrene, polyimide, polyurethane, polyamide, polymethyl methacrylate, copolymer nylon, epoxy resin, ultraviolet curable acrylic resin, A silicone resin, a fluororesin, etc. are mentioned.
　表面層４２及び表面層４８の材料の例としては、分散媒５０がシリコーンオイルである場合、粒子の固着防止の観点から、シリコーン鎖を有する高分子化合物が好適に挙げられる。
　シリコーン鎖を持つ高分子化合物としては、例えば、下記構成単位（Ａ）と下記構成単位（Ｂ）とを含む共重合体が適用できる。 As an example of the material of the surface layer 42 and the surface layer 48, when the dispersion medium 50 is a silicone oil, the high molecular compound which has a silicone chain is mentioned suitably from a viewpoint of adhesion prevention of particle | grains.
As the polymer compound having a silicone chain, for example, a copolymer containing the following structural unit (A) and the following structural unit (B) can be applied.
Figure JPOXMLDOC01-appb-C000001
Figure JPOXMLDOC01-appb-C000001
　構成単位（Ａ）及び（Ｂ）中、Ｘは、シリコーン鎖を含む基を表す。
　Ｒａ１は、水素原子、又はメチル基を表す。
　Ｒａ２は、水素原子、メチル基、又はハロゲン原子（例えば塩素原子）を表す。
　Ｒｂ２は、水素原子、アルキル基、アルケニル基、シアノ基、芳香族基、複素環基、又は－Ｃ（＝Ｏ）－Ｏ－Ｒｃ２（但し、Ｒｃ２は、アルキル基、ヒドロキシアルキル基、ポリオキシアルキル基（－（ＣｘＨ２ｘ－Ｏ）ｎ－Ｈ［ｘ，ｎ＝１以上の整数］）、アミノ基、モノアルキルアミノ基、又はジアルキルアミノ基を表す。）
　ｎ１、及びｎ２は、共重合体全体に対するそれぞれの構成単位のモル％を示し、０＜ｎ１＜５０、０＜ｎ２＜８０を表す。ｎは、１以上３以下の自然数を表す。 In the structural units (A) and (B), X represents a group containing a silicone chain.
Ra 1 represents a hydrogen atom or a methyl group.
Ra 2 represents a hydrogen atom, a methyl group, or a halogen atom (for example, a chlorine atom).
Rb 2 represents a hydrogen atom, an alkyl group, an alkenyl group, a cyano group, an aromatic group, a heterocyclic group, or —C (═O) —O—Rc 2 (where Rc 2 represents an alkyl group, a hydroxyalkyl group, Represents a polyoxyalkyl group (-(C x H 2x -O) n -H [x, n is an integer of 1 or more]), an amino group, a monoalkylamino group, or a dialkylamino group.)
n1 and n2 represent mol% of each structural unit with respect to the entire copolymer, and represent 0 <n1 <50 and 0 <n2 <80. n represents a natural number of 1 or more and 3 or less.
　構成単位（Ａ）中、Ｘが表すシリコーン鎖を含む基は、例えば、直鎖状、又は分枝状のシリコーン鎖（Ｓｉ－Ｏ結合が２つ以上連なったシロキサン鎖）を含む基であり、好適には、ジメチルシロキサン構造（－Ｓｉ（ＣＨ３）２－Ｏ－）が２以上連なった、置換基で一部（－ＣＨ３の一部）が置換されていてもよいジメチルシロキサン鎖を含む基である。　Ｘが表すシリコーン鎖を含む基として具体的には、例えば、下記構造式（Ｘ１）、又は（Ｘ２）で示される基が挙げられる。 In the structural unit (A), the group containing a silicone chain represented by X is, for example, a group containing a linear or branched silicone chain (a siloxane chain in which two or more Si—O bonds are linked), Preferably, it includes a dimethylsiloxane chain in which two or more dimethylsiloxane structures (—Si (CH 3 ) 2 —O—) are connected, and a part thereof (part of —CH 3 ) may be substituted. It is a group. Specific examples of the group containing a silicone chain represented by X include a group represented by the following structural formula (X1) or (X2).
Figure JPOXMLDOC01-appb-C000002
Figure JPOXMLDOC01-appb-C000002
　構造式（Ｘ１）及び（Ｘ２）中、Ｒ１は、水酸基、水素原子、又は炭素数１以上１０以下のアルキル基を表す。ｎは、１以上１０以下の整数を表す。 In Structural Formulas (X1) and (X2), R 1 represents a hydroxyl group, a hydrogen atom, or an alkyl group having 1 to 10 carbon atoms. n represents an integer of 1 to 10.
　シリコーン鎖を持つ高分子化合物において、構造単位（Ａ）の単量体として具体的には、例えば、片末端に（メタ）アクリレート基を持ったジメチルシリコーンモノマー（例えば、チッソ社製：サイラプレーンＦＭ－０７１１，ＦＭ－０７２１，ＦＭ－０７２５等（全て商品名）、信越化学工業（株）：Ｘ－２２－１７４ＤＸ，Ｘ－２２－２４２６，Ｘ－２２－２４７５等（全て商品名））等が挙げられる。これらの中でも、サイラプレーンＦＭ－０７１１、ＦＭ－０７２１、ＦＭ－０７２５等が好ましい。 In the polymer compound having a silicone chain, as a monomer of the structural unit (A), specifically, for example, a dimethyl silicone monomer having a (meth) acrylate group at one end (for example, Silasplain FM manufactured by Chisso Corporation) -0711, FM-0721, FM-0725, etc. (all trade names), Shin-Etsu Chemical Co., Ltd .: X-22-174DX, X-22-2426, X-22-2475, etc. (all trade names)) Can be mentioned. Among these, Silaplane FM-0711, FM-0721, FM-0725, etc. are preferable.
　構成単位（Ｂ）の単量体としては、例えば、（メタ）アクリロニトリル、メタクリル酸メチル、メタクリル酸ブチルなどの（メタ）アクリル酸アルキルエステル、（メタ）アクリルアミド、エチレン、プロピレン、ブタジエン、イソプレン、イソブチレン、Ｎ－ジアルキル置換（メタ）アクリルアミド、スチレン、ビニルカルバゾール、スチレン、スチレン誘導体、ポリエチレングリコールモノ（メタ）アクリレート、塩化ビニル、塩化ビニリデン、イソプレン、ブタジエン、ビニルピロリドン、ヒドロキシエチル(メタ)アクリレート、ヒドロキシブチル(メタ)アクリレートなどが挙げられる。なお、これらの表記において、「（メタ）アクリレート」等の記述は、「アクリレート」および「メタクリレート」等のいずれをも含む表現である。 Examples of the monomer of the structural unit (B) include (meth) acrylonitrile, (meth) acrylic acid alkyl esters such as methyl methacrylate and butyl methacrylate, (meth) acrylamide, ethylene, propylene, butadiene, isoprene, and isobutylene. , N-dialkyl-substituted (meth) acrylamide, styrene, vinyl carbazole, styrene, styrene derivatives, polyethylene glycol mono (meth) acrylate, vinyl chloride, vinylidene chloride, isoprene, butadiene, vinyl pyrrolidone, hydroxyethyl (meth) acrylate, hydroxybutyl Examples include (meth) acrylate. In these notations, the description such as “(meth) acrylate” is an expression including both “acrylate” and “methacrylate”.
　シリコーン鎖を持つ高分子化合物は、構造単位（Ａ）及び（Ｂ）以外に架橋単位を含んでもよい。架橋単位としては、例えば、エポキシ基、オキサゾリン基、又はイソシアネート基などを含む単量体が利用できる。 The polymer compound having a silicone chain may contain a crosslinking unit in addition to the structural units (A) and (B). As the crosslinking unit, for example, a monomer containing an epoxy group, an oxazoline group, an isocyanate group, or the like can be used.
　シリコーン鎖を持つ高分子化合物の重量平均分子量は、１００以上１００万以下が望ましく、より好ましくは４００以上１００万以下である。なお、重量平均分子量は静的光散乱法又はサイズ排除カラムクロマトグラフィーにより測定され、本明細書に記載の数値は当該方法によって測定されたものである。 The weight average molecular weight of the polymer compound having a silicone chain is preferably from 100 to 1,000,000, more preferably from 400 to 1,000,000. The weight average molecular weight is measured by a static light scattering method or size exclusion column chromatography, and the numerical values described in this specification are measured by the method.
　シリコーン鎖を持つ高分子化合物を含む表面層（表面層４２、又は表面層４８）の厚みは、例えば、０．００１μｍ以上１０μｍ以下がよく、好ましくは０．０１μｍ以上１μｍ以下である。 The thickness of the surface layer (surface layer 42 or surface layer 48) containing a polymer compound having a silicone chain is, for example, 0.001 μm or more and 10 μm or less, and preferably 0.01 μm or more and 1 μm or less.
　表面層４２及び表面層４８の材料としては、上記した絶縁材料の他に、絶縁性材料中に電荷輸送物質を含有させたものも使用され得る。電荷輸送物質を含有させることにより、粒子への電荷注入による粒子帯電性の向上や、粒子の帯電量が極度に大きくなった場合に粒子の電荷を漏洩させ、粒子の帯電量を安定させるなどの効果が得られる。
　電荷輸送物質としては、例えば、正孔輸送物質であるヒドラゾン化合物、スチルベン化合物、ピラゾリン化合物、アリールアミン化合物等や、電子輸送物質であるフルオレノン化合物、ジフェノキノン誘導体、ピラン化合物、酸化亜鉛等や、ポリビニルカルバゾールなどの電荷輸送性を有する樹脂が挙げられる。 As the material for the surface layer 42 and the surface layer 48, in addition to the above-described insulating material, an insulating material containing a charge transporting substance may be used. Inclusion of a charge transport material improves particle chargeability by injecting particles into the particle, and when the charge amount of the particle becomes extremely large, the charge of the particle is leaked and the charge amount of the particle is stabilized. An effect is obtained.
Examples of charge transport materials include hole transport materials such as hydrazone compounds, stilbene compounds, pyrazoline compounds, and arylamine compounds, electron transport materials such as fluorenone compounds, diphenoquinone derivatives, pyran compounds, and zinc oxide, and polyvinylcarbazole. Examples thereof include resins having charge transport properties such as
間隙部材
　間隙部材２４は、表示基板２０と背面基板２２との間隙を保持するための部材であり、表示基板２０の透明性を損なわないように形成され、熱可塑性樹脂、熱硬化性樹脂、電子線硬化樹脂、光硬化樹脂、ゴム、又は金属等で形成される。間隙部材２４の、セルの内側となる表面に表面層２５が設けられている。表面層２５の材料及び厚みについては、前述の表面層４２及び４８と同じである。
　間隙部材２４には、セル状のものと、粒子状のものがある。セル状のものとしては、例えば、網や、エッチングやレーザー加工等によりマトリックス状に穴を開けたシートが挙げられる。
　間隙部材２４は表示基板２０及び背面基板２２の何れか一方と一体化されてもよく、支持基板３８又は支持基板４４をエッチング処理、もしくはレーザー加工したり、又は予め作製した型を使用し、プレス加工もしくは印刷等によって、任意のサイズのセルパターンを有する支持基板３８又は支持基板４４、及び間隙部材２４が作製される。この場合、間隙部材２４は、表示基板２０側、背面基板２２側のいずれか、又は双方に作製し得る。間隙部材２４は有色でもよいが、表示媒体１２に表示される表示画像に悪影響を及ぼさないように無色透明であることが好ましい。 Gap Member The gap member 24 is a member for holding a gap between the display substrate 20 and the back substrate 22 and is formed so as not to impair the transparency of the display substrate 20, and is made of a thermoplastic resin, a thermosetting resin, an electronic device. It is formed of a line curable resin, a photo curable resin, rubber, metal, or the like. A surface layer 25 is provided on the inner surface of the gap member 24. The material and thickness of the surface layer 25 are the same as those of the surface layers 42 and 48 described above.
The gap member 24 includes a cell type and a particle type. Examples of the cellular shape include a net or a sheet having holes formed in a matrix shape by etching or laser processing.
The gap member 24 may be integrated with either the display substrate 20 or the back substrate 22, and the support substrate 38 or the support substrate 44 is etched or laser processed, or a prefabricated mold is used and pressed. The support substrate 38 or the support substrate 44 having a cell pattern of any size and the gap member 24 are manufactured by processing or printing. In this case, the gap member 24 can be fabricated on either the display substrate 20 side, the back substrate 22 side, or both. The gap member 24 may be colored, but is preferably colorless and transparent so as not to adversely affect the display image displayed on the display medium 12.
電圧印加部
　電圧印加部１６は、表面電極４０及び背面電極４６に電気的に接続されている。なお、本実施の形態では、表面電極４０及び背面電極４６の双方が、電圧印加部１６に電気的に接続されている場合を説明するが、表面電極４０及び背面電極４６の一方が接地されており、他方が電圧印加部１６に接続されていてもよい。
　電圧印加部１６は、表面電極４０及び背面電極４６に電圧を印加するための電圧印加装置（例えば電源）であり、制御部１８の制御に応じた電圧を表面電極４０及び背面電極４６間に印加する。 Voltage Application Unit The voltage application unit 16 is electrically connected to the front electrode 40 and the back electrode 46. In this embodiment, the case where both the front electrode 40 and the back electrode 46 are electrically connected to the voltage application unit 16 will be described. However, one of the front electrode 40 and the back electrode 46 is grounded. The other may be connected to the voltage application unit 16.
The voltage application unit 16 is a voltage application device (for example, a power supply) for applying a voltage to the surface electrode 40 and the back electrode 46, and applies a voltage between the surface electrode 40 and the back electrode 46 according to the control of the control unit 18. To do.
制御部
　制御部１８は、電圧印加部１６に信号授受可能に接続されている。
　制御部１８は、図示しないが、装置全体の動作を司るＣＰＵ（中央処理装置）と、各種データを一時的に記憶するＲＡＭ（Random　Access　Memory）と、装置全体を制御する制御プログラムや処理ルーチンによって示されるプログラムを含む各種プログラムが予め記憶されたＲＯＭ（Read Only Memory）と、を含むマイクロコンピュータである。 Control Unit The control unit 18 is connected to the voltage application unit 16 so as to be able to exchange signals.
Although not shown, the control unit 18 includes a CPU (Central Processing Unit) that controls the operation of the entire apparatus, a RAM (Random Access Memory) that temporarily stores various data, and a control program and processing routine that control the entire apparatus. A microcomputer including a ROM (Read Only Memory) in which various programs including the program shown are stored in advance.
駆動方法
　本実施形態に係る画像表示装置１０では、表示媒体１２において、表示基板２０と背面基板２２との間に印加する印加電圧（Ｖ）を変えることによって、異なる色を表示する。
　表示媒体１２では、表示基板２０と背面基板２２との間に形成された電界に応じて着色粒子が移動することによって、表示媒体１２の各画素に対応するセル毎に、画像データの各画素に応じた色を表示することができる。 Driving Method In the image display apparatus 10 according to the present embodiment, the display medium 12 displays different colors by changing the applied voltage (V) applied between the display substrate 20 and the back substrate 22.
In the display medium 12, the colored particles move in accordance with the electric field formed between the display substrate 20 and the back substrate 22, so that each pixel corresponding to each pixel of the display medium 12 is assigned to each pixel of the image data. A corresponding color can be displayed.
　ここで、表示媒体１２において、上述のように、図２に示すように、着色粒子群３４においては、各色毎に、着色粒子群３４が基板間を電気泳動する際の電界に応じて移動するために必要な電圧の絶対値がそれぞれ異なる。そして、各色の着色粒子群３４は、各色毎に各色の着色粒子群３４を移動させるために必要な電圧範囲を有し、当該電圧範囲がそれぞれ異なる。言い換えれば、当該電圧の絶対値は、当該電圧範囲を有し、着色粒子群３４の各色毎に当該電圧範囲がそれぞれ異なる。 Here, in the display medium 12, as described above, as shown in FIG. 2, in the colored particle group 34, the colored particle group 34 moves for each color according to the electric field when electrophoresis is performed between the substrates. Therefore, the absolute value of the voltage required for each is different. The colored particle group 34 for each color has a voltage range necessary for moving the colored particle group 34 for each color, and the voltage range is different. In other words, the absolute value of the voltage has the voltage range, and the voltage range is different for each color of the colored particle group 34.
　なお、本実施形態では、表示媒体１２の同一セル内に封入されている着色粒子群３４としては、図１に示すように、マゼンタ色のマゼンタ粒子群３４Ｍ、シアン色のシアン粒子群３４Ｃ、及びイエロー色のイエロー粒子群３４Ｙの３色の着色粒子群３４が封入されているとして説明する。 In the present embodiment, as the colored particle group 34 enclosed in the same cell of the display medium 12, as shown in FIG. 1, a magenta magenta particle group 34M, a cyan cyan particle group 34C, and The description will be made assuming that the three colored particles 34 of the yellow yellow particle group 34Y are enclosed.
　マゼンタ色のマゼンタ粒子群３４Ｍ、シアン色のシアン粒子群３４Ｃ、及びイエロー色のイエロー粒子群３４Ｙの３色の粒子群各々が移動を開始するときの電圧の絶対値として、マゼンタ色のマゼンタ粒子群３４Ｍが｜Ｖｔｍ｜、シアン色のシアン粒子群３４Ｃが｜Ｖｔｃ｜、イエロー色のイエロー粒子群３４Ｙが｜Ｖｔｙ｜であるとして説明する。また、各色の着色粒子群３４のゼンタ色のマゼンタ粒子群３４Ｍ、シアン色のシアン粒子群３４Ｃ、及びイエロー色のイエロー粒子群３４Ｙの３色の粒子群各々をほぼ全て移動させるための最大電圧の絶対値として、マゼンタ色のマゼンタ粒子群３４Ｍが｜Ｖｄｍ｜、シアン色のシアン粒子群３４Ｃが｜Ｖｄｃ｜、イエロー色のイエロー粒子群３４Ｙが｜Ｖｄｙ｜であるとして説明する。 The magenta magenta particle group 34M, the cyan cyan particle group 34C, and the yellow color yellow particle group 34Y are used as absolute values of voltages when the three color particle groups start moving. It is assumed that 34M is | Vtm |, the cyan cyan particle group 34C is | Vtc |, and the yellow yellow particle group 34Y is | Vty |. Further, the maximum voltage for moving almost all of the three color particle groups of the magenta particle group 34M, the cyan cyan particle group 34C, and the yellow yellow particle group 34Y of the colored particle group 34 of each color is set. As absolute values, it is assumed that the magenta magenta particle group 34M is | Vdm |, the cyan cyan particle group 34C is | Vdc |, and the yellow yellow particle group 34Y is | Vdy |.
　以下で説明するＶｔｃ、－Ｖｔｃ、Ｖｄｃ、－Ｖｄｃ、Ｖｔｍ、－Ｖｔｍ、Ｖｄｍ、－Ｖｄｍ、Ｖｔｙ、－Ｖｔｙ、Ｖｄｙ、及び－Ｖｄｙの絶対値は、｜Ｖｔｃ｜＜｜Ｖｄｃ｜＜｜Ｖｔｍ｜＜｜Ｖｄｍ｜＜｜Ｖｔｙ｜＜｜Ｖｄｙ｜の関係であるとして説明する。
　具体的には、図２に示すように、例えば、着色粒子群３４はすべて同極性に帯電され、シアン粒子群３４Ｃを移動させるために必要な電圧範囲の絶対値｜Ｖｔｃ≦Ｖｃ≦Ｖｄｃ｜（ＶｔｃからＶｄｃの間の値の絶対値）、マゼンタ粒子群３４Ｍを移動させるために必要な電圧範囲の絶対値｜Ｖｔｍ≦Ｖｍ≦Ｖｄｍ｜（ＶｔｍからＶｄｍの間の値の絶対値）、及びイエロー粒子群３４Ｍを移動させるために必要な電圧範囲の絶対値｜Ｖｔｙ≦Ｖｙ≦Ｖｄｙ｜（ＶｔｙからＶｄｙの間の値の絶対値）が、この順で重複することなく、大きくなるように設定されている。 The absolute values of Vtc, −Vtc, Vdc, −Vdc, Vtm, −Vtm, Vdm, −Vdm, Vty, −Vty, Vdy, and −Vdy described below are expressed as | Vtc | <| Vdc | <| Vtm | In the following description, it is assumed that the relationship is <| Vdm | <| Vty | <| Vdy |.
Specifically, as shown in FIG. 2, for example, all the colored particle groups 34 are charged to the same polarity, and the absolute value of the voltage range necessary to move the cyan particle group 34C | Vtc ≦ Vc ≦ Vdc | ( Absolute value of a value between Vtc and Vdc), absolute value of voltage range necessary to move the magenta particle group 34M | Vtm ≦ Vm ≦ Vdm | (absolute value of a value between Vtm and Vdm), and yellow The absolute value of the voltage range necessary to move the particle group 34M | Vty ≦ Vy ≦ Vdy | (the absolute value of the value between Vty and Vdy) is set so as to increase without overlapping in this order. ing.
　また、各色の着色粒子群３４を独立駆動するために、シアン粒子群３４Ｍをほぼ全て移動させるための最大電圧の絶対値｜Ｖｄｃ｜が、マゼンタ粒子群３４Ｍを移動させるために必要な電圧範囲の絶対値｜Ｖｔｍ≦Ｖｍ≦Ｖｄｍ｜（ＶｔｍからＶｄｍの間の値の絶対値）、及びイエロー粒子群３４Ｍを移動させるために必要な電圧範囲の絶対値｜Ｖｔｙ≦Ｖｙ≦Ｖｄｙ｜（ＶｔｙからＶｄｙの間の値の絶対値）よりも小さく設定されている。また、マゼンタ粒子群３４Ｍをほぼ全て移動させるための最大電圧の絶対値｜Ｖｄｍ｜が、イエロー粒子群３４Ｍを移動させるために必要な電圧範囲の絶対値｜Ｖｔｙ≦Ｖｙ≦Ｖｄｙ｜（ＶｔｙからＶｄｙの間の値の絶対値）よりも小さく設定されている。 Further, in order to independently drive the colored particle groups 34 of the respective colors, the absolute value | Vdc | of the maximum voltage for moving almost all of the cyan particle groups 34M is within the voltage range necessary for moving the magenta particle group 34M. Absolute value | Vtm ≦ Vm ≦ Vdm | (absolute value between Vtm and Vdm), and absolute value of voltage range necessary to move yellow particle group 34M | Vty ≦ Vy ≦ Vdy | (Vty to Vdy) Is set to be smaller than the absolute value). Further, the absolute value | Vdm | of the maximum voltage for moving almost all of the magenta particle group 34M is equal to the absolute value | Vty ≦ Vy ≦ Vdy | (Vty to Vdy) of the voltage range necessary for moving the yellow particle group 34M. Is set to be smaller than the absolute value).
　即ち、本実施形態では、各色の着色粒子群３４を移動させるために必要な電圧範囲が重ならないように設定することによって、各色の着色粒子群３４が独立駆動されるようにしている。
　なお、「着色粒子群３４を移動させるために必要な電圧範囲」とは、粒子が移動開始するために必要な電圧と移動開始からさらに電圧及び電圧印加時間を増加させても、表示濃度の変化が生じなくなり、表示濃度が飽和するまでの電圧範囲を示す。
　また、「着色粒子群３４をほぼ全て移動させるために必要な最大電圧」とは上記の移動開始からさらに電圧及び電圧印加時間を増加させても、表示濃度の変化が生じなくなり、表示濃度が飽和する電圧を示す。 That is, in this embodiment, the color particle groups 34 of each color are driven independently by setting the voltage ranges necessary for moving the color particle groups 34 of each color so as not to overlap.
The “voltage range necessary for moving the colored particle group 34” means the voltage necessary for the particle to start moving and the change in display density even if the voltage and voltage application time are further increased from the start of movement. Indicates a voltage range until the display density is saturated.
The “maximum voltage necessary for moving almost all the colored particle groups 34” means that even if the voltage and voltage application time are further increased from the start of the above movement, the display density does not change and the display density is saturated. Indicates the voltage to be used.
　また、「ほぼ全て」とは、各色の着色粒子群３４の特性ばらつきがあるため、一部の着色粒子群３４の特性が表示特性に寄与しない程度異なるものがあることを表す。すなわち上述した移動開始からさらに電圧及び電圧印加時間を増加させても、表示濃度の変化が生じなくなり、表示濃度が飽和した状態である。 In addition, “almost all” means that there are variations in the characteristics of some of the colored particle groups 34 of each color, so that some of the characteristics of the colored particle groups 34 do not contribute to the display characteristics. That is, even if the voltage and the voltage application time are further increased from the start of the movement described above, the display density does not change and the display density is saturated.
　また、「表示濃度」は、表示面側における色濃度を光学濃度（Ｏｐｔｉｃａｌ　Ｄｅｎｓｉｔｙ＝０Ｄ）の反射濃度計Ｘ－ｒｉｔｅ社の反射濃度計で測定しながら、表示面側と背面側との間に電圧を印加して且つこの電圧を測定濃度が増加する方向に徐々に変化（印加電圧を増加又は減少）させて、単位電圧あたりの濃度変化が飽和し、且つその状態で電圧及び電圧印加時間を増加させても濃度変化が生じず、濃度が飽和したときの濃度を示している。
　そして、本実施形態に係る表示媒体１２では、表面基板２０と背面基板２２との基板間に０Ｖから電圧を印加して除々に印加電圧の電圧値を上昇させて、基板間に印加された電圧が＋Ｖｔｃを超えると、表示媒体１２においてシアン粒子群３４Ｃの移動により表示濃度に変化が現れ始める。さらに、電圧値を上昇させて、基板間に印加された電圧が＋Ｖｄｃとなると、表示媒体１２においてシアン粒子群３４の移動による表示濃度の変化が止まる。 The “display density” is a color density on the display surface side measured with a reflection densitometer of an optical density (Optical Density = 0D) reflection densitometer of X-rite. Apply a voltage and gradually change this voltage in the direction of increasing the measured concentration (increase or decrease the applied voltage) to saturate the concentration change per unit voltage, and in that state, adjust the voltage and voltage application time. Even when the density is increased, the density does not change, and the density is shown when the density is saturated.
In the display medium 12 according to this embodiment, the voltage applied between the substrates is gradually increased by applying a voltage from 0 V between the front substrate 20 and the rear substrate 22 to increase the voltage value of the applied voltage. When the value exceeds + Vtc, the display density starts to change due to the movement of the cyan particle group 34C in the display medium 12. Further, when the voltage value is increased and the voltage applied between the substrates becomes + Vdc, the change in display density due to the movement of the cyan particle group 34 in the display medium 12 stops.
　さらに、電圧値を上昇させて、表面基板２０と背面基板２２との基板間に印加された電圧が＋Ｖｔｍを超えると、表示媒体１２においてマゼンタ粒子群３４Ｍの移動による表示濃度の変化が現れ始める。さらに電圧値を上昇させて、表面基板２０と背面基板２２との基板間に印加された電圧が＋Ｖｄｍとなると、表示媒体１２においてマゼンタ粒子群３４Ｍの移動による表示濃度の変化が止まる。 Further, when the voltage value is increased and the voltage applied between the front substrate 20 and the rear substrate 22 exceeds + Vtm, a change in display density due to the movement of the magenta particle group 34M starts to appear in the display medium 12. When the voltage value is further increased and the voltage applied between the front substrate 20 and the rear substrate 22 becomes + Vdm, the change in display density due to the movement of the magenta particle group 34M in the display medium 12 stops.
　さらに、電圧値を上昇させて、基板間に印加された電圧が＋Ｖｔｙを超えると、表示媒体１２においてイエロー粒子群３４Ｙの移動による表示濃度の変化が現れ始める。さらに電圧値を上昇させて、基板間に印加された電圧が＋Ｖｄｙとなると、表示媒体１２においてイエロー粒子群３４Ｙの移動による表示濃度の変化が止まる。
　反対に、表面基板２０と背面基板２２との基板間に０Ｖからマイナス極の電圧を印加して除々に電圧の絶対値を上昇させ、基板間に印加された電圧－Ｖｔｃの絶対値を超えると、表示媒体１２においてイエロー粒子群３４Ｃの基板間の移動により表示濃度に変化が現れ始める。さらに、電圧値の絶対値を上昇させ、表面基板２０と背面基板２２との基板間に印加された電圧が－Ｖｄｃ以上となると、表示媒体１２においてシアン粒子群３４Ｃの移動による表示濃度の変化が止まる。 Further, when the voltage value is increased and the voltage applied between the substrates exceeds + Vty, a change in display density due to the movement of the yellow particle group 34Y starts to appear in the display medium 12. When the voltage value is further increased and the voltage applied between the substrates becomes + Vdy, the change in display density due to the movement of the yellow particle group 34Y in the display medium 12 stops.
On the other hand, when the negative voltage from 0V is applied between the front substrate 20 and the rear substrate 22 to gradually increase the absolute value of the voltage and the absolute value of the voltage −Vtc applied between the substrates is exceeded. In the display medium 12, the display density starts to change due to the movement of the yellow particle group 34C between the substrates. Further, when the absolute value of the voltage value is increased and the voltage applied between the front substrate 20 and the rear substrate 22 becomes −Vdc or more, the display density changes due to the movement of the cyan particle group 34C in the display medium 12. Stop.
　さらに、電圧値の絶対値を上昇させてマイナス極の電圧を印加し、表面基板２０と背面基板２２との基板間に印加される電圧が－Ｖｔｍの絶対値を超えると、表示媒体１２においてマゼンタ粒子群３４Ｍの移動による表示濃度の変化が現れ始める。さらに電圧値の絶対値を上昇させて、表面基板２０と背面基板２２との基板間に印加された電圧が－Ｖｄｍとなると、表示媒体１２においてマゼンタ粒子群３４Ｍの移動による表示濃度の変化が止まる。 Further, when the negative voltage is applied by increasing the absolute value of the voltage value and the voltage applied between the front substrate 20 and the rear substrate 22 exceeds the absolute value of −Vtm, the display medium 12 displays magenta. A change in display density due to the movement of the particle group 34M begins to appear. When the absolute value of the voltage value is further increased and the voltage applied between the front substrate 20 and the rear substrate 22 becomes −Vdm, the change in display density due to the movement of the magenta particle group 34M in the display medium 12 stops. .
　さらに、電圧値の絶対値を上昇させてマイナス極の電圧を印加し、表面基板２０と背面基板２２との基板間に印加される電圧が－Ｖｔｙの絶対値を超えると、表示媒体１２においてイエロー粒子群３４Ｙの移動により表示濃度に変化が現れ始める。さらに電圧値の絶対値を上昇させて、基板間に印加された電圧が－Ｖｄｙとなると、表示媒体１２においてイエロー粒子群３４Ｃの移動による表示濃度の変化が止まる。 Further, when the negative voltage is applied by increasing the absolute value of the voltage value and the voltage applied between the front substrate 20 and the rear substrate 22 exceeds the absolute value of −Vty, the display medium 12 displays yellow. Changes in the display density begin to appear due to the movement of the particle group 34Y. When the absolute value of the voltage value is further increased and the voltage applied between the substrates becomes −Vdy, the change in display density due to the movement of the yellow particle group 34C in the display medium 12 stops.
　すなわち、本実施形態では、図２に示すように、基板間に印加される電圧が－ＶｔｃからＶｔｃの範囲内（電圧範囲｜Ｖｔｃ｜以下）となるような電圧が表面基板２０と背面基板２２との基板間に印加された場合には、表示媒体１２の表示濃度に変化が発生する程度の着色粒子群３４（シアン粒子群３４Ｃ、マゼンタ粒子群３４Ｍ、及びイエロー粒子群３４Ｙ）の粒子の移動は生じていないといえる。そして、基板間に、電圧＋Ｖｔｃ及び電圧－Ｖｔｃの絶対値以上の電圧が印加されると、３色の着色粒子群３４の内のシアン粒子群３４Ｃについて表示媒体１２の表示濃度に変化が発生する程度の粒子の移動が生じはじめて表示濃度に変化が生じはじめ、電圧－Ｖｄｃ及び電圧Ｖｄｃの絶対値｜Ｖｄｃ｜以上の電圧が印加されると、単位電圧あたりの表示濃度に変化は生じなくなる。 That is, in the present embodiment, as shown in FIG. 2, the voltages applied between the substrates are within the range of −Vtc to Vtc (voltage range | Vtc | or less), so that the front substrate 20 and the rear substrate 22 Are applied between the substrates, the movement of the particles of the colored particle group 34 (the cyan particle group 34C, the magenta particle group 34M, and the yellow particle group 34Y) to the extent that the display density of the display medium 12 changes. Is not occurring. When a voltage equal to or higher than the absolute values of the voltage + Vtc and the voltage −Vtc is applied between the substrates, a change occurs in the display density of the display medium 12 for the cyan particle group 34C among the three color particle groups 34. The display density starts to change only when a certain amount of particle movement starts to occur, and when a voltage higher than the voltage −Vdc and the absolute value | Vdc | of the voltage Vdc is applied, the display density per unit voltage does not change.
　さらに、基板間に印加される電圧が－ＶｔｍからＶｔｍの範囲内（電圧範囲｜Ｖｔｍ｜以下）となるような電圧が表面基板２０と背面基板２２との基板間に印加された場合には、表示媒体１２の表示濃度に変化が発生する程度のマゼンタ粒子群３４Ｍ及びイエロー粒子群３４Ｙの粒子の移動は生じていないといえる。そして、基板間に、電圧＋Ｖｔｍ及び電圧－Ｖｔｍの絶対値以上の電圧が印加されると、マゼンタ粒子群３４Ｍ及びイエロー粒子群３４Ｙの内のマゼンタ粒子群３４Ｍについて、表示媒体１２の表示濃度に変化が発生する程度の粒子の移動が生じはじめて単位電圧あたりの表示濃度に変化が生じはじめ、電圧－Ｖｄｍ及び電圧Ｖｄｍの絶対値｜Ｖｄｍ｜以上の電圧が印加されると、表示濃度に変化は生じなくなる。 Further, when a voltage is applied between the front substrate 20 and the rear substrate 22 such that the voltage applied between the substrates is in the range of −Vtm to Vtm (voltage range | Vtm | or less), It can be said that the movement of the particles of the magenta particle group 34M and the yellow particle group 34Y to the extent that the display density of the display medium 12 changes does not occur. When a voltage greater than the absolute value of the voltage + Vtm and the voltage −Vtm is applied between the substrates, the display density of the display medium 12 is changed for the magenta particle group 34M and the magenta particle group 34M of the yellow particle group 34Y. The display density per unit voltage starts to change to the extent that particles are generated, and when a voltage greater than the absolute value | Vdm | of the voltage −Vdm and the voltage Vdm is applied, the display density changes. Disappear.
　さらに、基板間に印加する電圧が－ＶｔｙからＶｔｙの範囲内（電圧範囲｜Ｖｔｙ｜以下）となるような電圧が表面基板２０と背面基板２２との基板間に印加された場合には、表示媒体１２の表示濃度に変化が発生する程度のイエロー粒子群３４Ｙの粒子の移動は生じていないといえる。そして、基板間に、電圧＋Ｖｔｙ及び電圧－Ｖｔｙの絶対値以上の電圧が印加されると、イエロー粒子群３４Ｙについて、表示媒体１２の表示濃度に変化が発生する程度の粒子の移動が生じ始めて表示濃度に変化が生じはじめ、電圧－Ｖｄｙ及び電圧Ｖｄｙの絶対値｜Ｖｄｙ｜以上の電圧が印加されると、表示濃度に変化は生じなくなる。 Further, when a voltage is applied between the front substrate 20 and the rear substrate 22 so that the voltage applied between the substrates is within the range of −Vty to Vty (voltage range | Vty | or less), the display It can be said that the movement of the particles of the yellow particle group 34Y to the extent that the display density of the medium 12 changes does not occur. When a voltage higher than the absolute value of the voltage + Vty and the voltage −Vty is applied between the substrates, the yellow particle group 34Y starts to move and display a particle that causes a change in the display density of the display medium 12. When the density starts to change and a voltage equal to or higher than the absolute value | Vdy | of the voltage −Vdy and the voltage Vdy is applied, the display density does not change.
　次に、図３を参照して、本実施形態に係る画像表示装置１０において、表示媒体１２に画像を表示するときの駆動方法を説明する。 Next, a driving method for displaying an image on the display medium 12 in the image display apparatus 10 according to the present embodiment will be described with reference to FIG.
　はじめに、表示基板２０と背面基板２２との間に電圧－Ｖｄｙを印加する。これにより、マゼンタ粒子群３４Ｍ、シアン粒子群３４Ｃ、及びイエロー粒子群３４Ｙの全てが背面基板２２側に位置される（図３（Ａ）参照）。 First, a voltage −Vdy is applied between the display substrate 20 and the rear substrate 22. Thereby, all of the magenta particle group 34M, the cyan particle group 34C, and the yellow particle group 34Y are positioned on the back substrate 22 side (see FIG. 3A).
　つぎに、もっとも移動開始電圧が高いイエロー粒子群３４Ｙを移動させるか、そのままの状態とするかを選択する。電圧＋Ｖｄｙを印加した場合は、マゼンタ粒子群３４Ｍ、シアン粒子群３４Ｃ、及びイエロー粒子群３４Ｙの全てが表示基板２０側に移動して黒（Ｋ）表示となる（図３（Ｂ）参照）。一方、電圧＋Ｖｔｙを印加した場合は、マゼンタ粒子群３４Ｍ、シアン粒子群３４Ｃは表示基板２０側に移動するが、イエロー粒子群３４Ｙはそのままの状態となって背面基板２２側に残り青色（Ｂ）表示となる（図３（Ｃ）参照）。電圧が＋Ｖｔｙ以上、＋Ｖｄｙ以下の場合には、イエロー粒子群３４Ｙの一部が移動するので、中間調を得ることができる。 Next, it is selected whether the yellow particle group 34Y having the highest movement start voltage is moved or left as it is. When the voltage + Vdy is applied, all of the magenta particle group 34M, the cyan particle group 34C, and the yellow particle group 34Y move to the display substrate 20 side and display black (K) (see FIG. 3B). On the other hand, when the voltage + Vty is applied, the magenta particle group 34M and the cyan particle group 34C move to the display substrate 20 side, but the yellow particle group 34Y remains as it is and remains on the back substrate 22 side as blue (B). Display is made (see FIG. 3C). When the voltage is greater than or equal to + Vty and less than or equal to + Vdy, a part of the yellow particle group 34Y moves, so that a halftone can be obtained.
　つぎに、２番目に移動開始電圧が高いマゼンタ粒子群３４Ｍを移動させるか、そのままの状態とするかを選択する。電圧－Ｖｄｍを印加した場合は、マゼンタ粒子群３４Ｍは背面基板２２側へ移動し、一方、電圧－Ｖｔｍを印加した場合は、マゼンタ粒子群３４Ｍは表示基板２０側に残る。移動開始電圧がマゼンタ粒子３４Ｍより低いシアン粒子３４Ｃは、いずれの場合も背面基板２２側へ移動する。一方、移動開始電圧がマゼンタ粒子３４Ｍより高いイエロー粒子３４Ｙは、いずれの場合もそれ以前の状態（例えば、図３（Ａ）の状態又は図３（Ｂ）の状態）を維持する。電圧が－Ｖｔｍ以上、－Ｖｄｍ以下の場合には、マゼンタ粒子群３４Ｍの一部が移動するので、中間調を得ることができる。 Next, it is selected whether the magenta particle group 34M having the second highest movement start voltage is moved or left as it is. When the voltage −Vdm is applied, the magenta particle group 34M moves to the back substrate 22 side. On the other hand, when the voltage −Vtm is applied, the magenta particle group 34M remains on the display substrate 20 side. The cyan particles 34C whose movement start voltage is lower than the magenta particles 34M move to the back substrate 22 side in any case. On the other hand, the yellow particles 34Y whose movement start voltage is higher than the magenta particles 34M maintain the previous state (for example, the state of FIG. 3A or the state of FIG. 3B) in any case. When the voltage is −Vtm or more and −Vdm or less, a part of the magenta particle group 34M moves, so that a halftone can be obtained.
　したがって、図３（Ｂ）の状態で電圧－Ｖｄｍを印加した場合は、イエロー粒子３４Ｙは表示基板２０側に残ったままで、マゼンタ粒子３４Ｍとシアン粒子３４Ｃが背面電極２２側へ移動して、結果として黄色（Ｙ）表示となる（図３（Ｄ）参照）。
　図３（Ｂ）の状態で電圧－Ｖｔｍを印加した場合は、イエロー粒子３４Ｙとマゼンタ粒子３４Ｍが表示基板２０側に残ったままで、シアン粒子３４Ｃが背面電極２２側へ移動して、結果として赤色（Ｒ）表示となる（図３（Ｅ）参照）。
　図３（Ｃ）の状態で電圧－Ｖｄｍを印加した場合は、イエロー粒子３４Ｙは背面基板２２側に残ったままで、マゼンタ粒子３４Ｍとシアン粒子３４Ｃが背面電極２２側へ移動して、結果として白色（Ｗ）表示となる（図３（Ｆ）参照）。
　図３（Ｃ）の状態で電圧－Ｖｔｍを印加した場合は、イエロー粒子３４Ｙは背面基板２２側に残ったまま、マゼンタ粒子３４Ｍは表示基板２０側に残ったままで、シアン粒子３４Ｃが背面電極２２側へ移動して、結果としてマゼンタ（Ｍ）表示となる（図３（Ｇ）参照）。 Therefore, when the voltage −Vdm is applied in the state of FIG. 3B, the yellow particles 34Y remain on the display substrate 20 side, and the magenta particles 34M and the cyan particles 34C move to the back electrode 22 side. As yellow (Y) display (see FIG. 3D).
When the voltage −Vtm is applied in the state of FIG. 3B, the cyan particles 34C move to the back electrode 22 side while the yellow particles 34Y and the magenta particles 34M remain on the display substrate 20 side, resulting in a red color. (R) is displayed (see FIG. 3E).
When the voltage −Vdm is applied in the state of FIG. 3C, the yellow particles 34Y remain on the back substrate 22 side, and the magenta particles 34M and cyan particles 34C move to the back electrode 22 side, resulting in white (W) is displayed (see FIG. 3F).
When the voltage −Vtm is applied in the state of FIG. 3C, the yellow particles 34Y remain on the back substrate 22 side, the magenta particles 34M remain on the display substrate 20 side, and the cyan particles 34C remain on the back electrode 22. As a result, the display becomes magenta (M) (see FIG. 3G).
　最後に、移動開始電圧がもっとも低いシアン粒子３４Ｃを移動させるか、そのままの状態とするかを選択する。電圧＋Ｖｄｃを印加した場合は、シアン粒子群３４Ｃは表示基板２０側へ移動し、一方、電圧＋Ｖｔｃを印加した場合は、シアン粒子群３４Ｃは背面基板２２側に残る。移動開始電圧がシアン粒子群３４Ｃよりも高いマゼンタ粒子３４Ｍとイエロー粒子３４Ｙは、いずれの場合もそれ以前の状態を維持する。それゆえ、電圧＋Ｖｔｃを印加した場合は、それ以前の表示色を維持する。電圧が＋Ｖｔｃ以上、＋Ｖｄｃ以下の場合には、シアン粒子群３４Ｃの一部が移動するので、中間調を得ることができる。 Finally, it is selected whether the cyan particle 34C having the lowest movement start voltage is moved or left as it is. When the voltage + Vdc is applied, the cyan particle group 34C moves to the display substrate 20 side. On the other hand, when the voltage + Vtc is applied, the cyan particle group 34C remains on the back substrate 22 side. The magenta particles 34M and the yellow particles 34Y whose movement start voltage is higher than that of the cyan particle group 34C maintain the previous state in any case. Therefore, when the voltage + Vtc is applied, the previous display color is maintained. When the voltage is greater than or equal to + Vtc and less than or equal to + Vdc, part of the cyan particle group 34C moves, so that a halftone can be obtained.
　したがって、図３（Ｄ）の状態で電圧＋Ｖｄｃを印加した場合は、シアン粒子群３４Ｃは表示基板２０側へ移動し、イエロー粒子３４Ｙは表示基板２０側に、マゼンタ粒子３４Ｍが背面電極２２側に残ったままで、結果として緑色（Ｇ）表示となる（図３（Ｈ）参照）。
　図３（Ｅ）の状態で電圧＋Ｖｄｃを印加した場合は、シアン粒子群３４Ｃは表示基板２０側へ移動し、イエロー粒子３４Ｙとマゼンタ粒子３４Ｍは表示基板２０側に残ったままで、結果として黒色（Ｋ）表示となる（図３（Ｉ）参照）。
　図３（Ｆ）の状態で電圧＋Ｖｄｃを印加した場合は、シアン粒子群３４Ｃは表示基板２０側へ移動し、イエロー粒子３４Ｙはとマゼンタ粒子３４Ｍ背面電極２２側に残ったままで、結果としてシアン（Ｃ）表示となる（図３（Ｊ）参照）。
　図３（Ｇ）の状態で電圧＋Ｖｄｃを印加した場合は、シアン粒子群３４Ｃは表示基板２０側へ移動し、イエロー粒子３４Ｙは背面電極２２側に、とマゼンタ粒子３４Ｍは表示基板２０側に残ったままで、結果として青色（Ｂ）表示となる（図３（Ｋ）参照）。 Therefore, when the voltage + Vdc is applied in the state of FIG. 3D, the cyan particle group 34C moves to the display substrate 20 side, the yellow particles 34Y move to the display substrate 20 side, and the magenta particles 34M move to the back electrode 22 side. As a result, green (G) is displayed (see FIG. 3H).
When the voltage + Vdc is applied in the state of FIG. 3E, the cyan particle group 34C moves to the display substrate 20 side, and the yellow particles 34Y and the magenta particles 34M remain on the display substrate 20 side, resulting in black ( K) is displayed (see FIG. 3I).
When the voltage + Vdc is applied in the state of FIG. 3F, the cyan particle group 34C moves to the display substrate 20 side, and the yellow particles 34Y remain on the magenta particle 34M back electrode 22 side, resulting in cyan ( C) Display is made (see FIG. 3J).
When the voltage + Vdc is applied in the state of FIG. 3G, the cyan particle group 34C moves to the display substrate 20 side, the yellow particles 34Y remain on the back electrode 22 side, and the magenta particles 34M remain on the display substrate 20 side. As a result, blue (B) display is obtained (see FIG. 3K).
　このように、移動開始電圧が高い各着色粒子群３４から順に、その粒子群に応じた電圧を基板間に印加することで、所望の粒子を選択的に移動させて、任意のカラー表示が可能となる。 In this way, any color display can be performed by selectively moving desired particles by applying a voltage corresponding to the particle group between the substrates in order from each colored particle group 34 having a high movement start voltage. It becomes.
画像表示装置を備えた電子機器等
　本発明の画像表示装置は、電子機器、展示用媒体、カード媒体等に備えられる。
　具体的には、本発明の画像表示装置は、例えば、画像の保存及び書換えが可能な電子掲示板、電子回覧版、電子黒板、電子広告、電子看板、点滅標識、電子ペーパー、電子新聞、電子書籍、複写機・プリンタと共用できる電子ドキュメントシート、ポータブルコンピューター、タブレットコンピューター、携帯電話、スマートカード、署名機器、時計、棚ラベル、フラッシュドライブ等に備えられる。 Electronic device provided with image display device, etc. The image display device of the present invention is provided in an electronic device, an exhibition medium, a card medium, and the like.
Specifically, the image display device of the present invention includes, for example, an electronic bulletin board capable of storing and rewriting images, an electronic circulation version, an electronic blackboard, an electronic advertisement, an electronic signboard, a flashing sign, electronic paper, an electronic newspaper, and an electronic book. Electronic document sheets that can be shared with copiers and printers, portable computers, tablet computers, mobile phones, smart cards, signature devices, watches, shelf labels, flash drives, etc.
　以下に本発明を実施例を挙げてより詳細に説明するが、本発明は以下の実施例にのみ限定されるものではない。以下の実施例において特に言及しない限り、「％」は「質量％」である。
　なお、本実施例における各測定方法は、以下の通りである。 EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples. Unless otherwise specified in the following examples, “%” is “mass%”.
In addition, each measuring method in a present Example is as follows.
測定方法
粒子の体積平均粒径の測定
　粒子の体積平均粒径は、コールターマルチサイザー－ＩＩ型（商品名；ベックマン－コールター社製）を用いて、５０μｍのアパーチャー径で測定した。この時、測定は粒子を電解質水溶液（アイソトン水溶液、ベックマン－コールター社製）に分散させ、超音波により３０秒以上分散させた後に行う。
　測定法としては、分散剤として界面活性剤（アルキルベンゼンスルホン酸ナトリウム）の５％水溶液２ｍｌ中に、測定試料を０．５ｍｇ～５０ｍｇ加え、これを電解液１００ｍｌ～１５０ｍｌ中に添加する。この測定試料を懸濁させた電解液を超音波分散器で約１分間分散処理を行い、粒子の粒度分布を測定する。測定する粒子数は５０，０００である。
　測定された粒度分布を、分割された粒度範囲（チャンネル）に対し、体積について小径側から累積分布を描き、累積５０％となる粒径を体積平均粒径と定義する。 Measuring Method Measurement of Volume Average Particle Size of Particles The volume average particle size of the particles was measured using a Coulter Multisizer-type II (trade name; manufactured by Beckman-Coulter) with an aperture diameter of 50 μm. At this time, the measurement is performed after the particles are dispersed in an electrolyte aqueous solution (Isoton aqueous solution, manufactured by Beckman Coulter, Inc.) and dispersed by ultrasonic waves for 30 seconds or more.
As a measurement method, 0.5 mg to 50 mg of a measurement sample is added to 2 ml of a 5% aqueous solution of a surfactant (sodium alkylbenzene sulfonate) as a dispersant, and this is added to 100 ml to 150 ml of an electrolytic solution. The electrolytic solution in which the measurement sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 minute, and the particle size distribution of the particles is measured. The number of particles to be measured is 50,000.
For the measured particle size distribution, a cumulative distribution is drawn from the smaller diameter side with respect to the divided particle size range (channel), and the particle size at which 50% is accumulated is defined as the volume average particle size.
粒子の顔料含有量の測定
　粒子の分散液を１２０℃で１．５時間乾燥させた後の質量をｗａ、さらに５５０℃で１時間燃焼させた後の質量をｗｂとし、（ｗａ－ｗｂ／ｗａ）×１００から顔料含有量を求めた。 Measurement of the pigment content of particles The mass after drying the particle dispersion at 120 ° C. for 1.5 hours is wa, and the mass after burning at 550 ° C. for 1 hour is wb, and (wa−wb / wa The pigment content was determined from x100.
粒子の比重の測定
　粒子の比重は、それに含まれる顔料の含有量、顔料の比重、及び樹脂の比重から算出した。
　そして、顔料及び樹脂の比重は、公知の固体の密度及び比重の測定方法（例えば、ＪＩＳ　Ｚ８８０７）に準じて測定した。 Measurement of specific gravity of particles The specific gravity of the particles was calculated from the content of the pigment contained therein, the specific gravity of the pigment, and the specific gravity of the resin.
The specific gravity of the pigment and the resin was measured according to a known solid density and specific gravity measurement method (for example, JIS Z8807).
分散媒の比重の測定
　分散媒の比重は、公知の液体の密度及び比重の測定方法（例えば、ＪＩＳ　Ｚ８８０４）に準じて測定した。 Measurement of specific gravity of dispersion medium The specific gravity of the dispersion medium was measured in accordance with a known method for measuring density and specific gravity of liquid (for example, JIS Z8804).
分散媒の粘度の測定
　分散媒の粘度は、東京計器製Ｂ－８Ｌ型粘度計（商品名）を用いて測定した（測定温度２０℃）。 Measurement of viscosity of dispersion medium The viscosity of the dispersion medium was measured using a B-8L viscometer (trade name) manufactured by Tokyo Keiki Co., Ltd. (measurement temperature: 20 ° C.).
粒子に含まれる樹脂のガラス転移温度の測定
　ガラス転移温度は、示差走査熱量計（島津製作所製のＤＳＣ－５０；商品名）を用い、ＪＩＳ　Ｋ７１２１－１９８７（ＩＳＯ　３１４６－１９８５に相当する）に準拠して測定した。この装置の検出部の温度補正にはインジウムと亜鉛との混合物の融点を用い、熱量の補正にはインジウムの融解熱を用いた。
　粒子をそのままアルミニウム製パンに入れ、粒子の入ったアルミニウム製パンと対照用の空のアルミニウム製パンとをセットし、昇温速度１０℃／ｍｉｎで測定を行った。
　測定により得られたＤＳＣ曲線の吸熱部におけるベースラインと立ち上がりラインとの延長線の交点の温度をもってガラス転移温度とした。 Measurement of glass transition temperature of resin contained in particle The glass transition temperature is based on JIS K7121-1987 (corresponding to ISO 3146-1985) using a differential scanning calorimeter (DSC-50 manufactured by Shimadzu Corporation; trade name). And measured. The melting point of a mixture of indium and zinc was used for temperature correction of the detection part of this apparatus, and the heat of fusion of indium was used for correction of heat quantity.
The particles were put in an aluminum pan as they were, and an aluminum pan containing particles and an empty aluminum pan for control were set, and measurement was performed at a heating rate of 10 ° C./min.
The glass transition temperature was defined as the temperature at the intersection of the extension line of the base line and the rising line in the endothermic part of the DSC curve obtained by the measurement.
実施例１：ＣＲＷ混合系
シアン粒子Ｃ１の作製
１）コア粒子の作製
分散相の調製
　下記成分を６０℃に加温しながら混合し、インク固形分濃度が１５％、乾燥後の顔料濃度が５０％となるように分散相を調製した。
・スチレンアクリル系ポリマーＸ３４５（商品名；星光ＰＭＣ社製）：　７．２ｇ
・シアン顔料ＰＢ１５：３の水分散液：　１８．８ｇ
　（Ｅｍａｃｏｌ　ＳＦ　Ｂｌｕｅ　Ｈ５２４Ｆ（商品名；山陽色素社製、固形分２６質量％））
・蒸留水：　２４．１ｇ Example 1 Production of CRW Mixed Cyan Particles C1 1) Production of Core Particles Preparation of Dispersed Phase The following components were mixed while heating to 60 ° C., the ink solid content concentration was 15%, and the pigment concentration after drying was 50 The disperse phase was prepared to be%.
Styrene acrylic polymer X345 (trade name; manufactured by Seiko PMC): 7.2 g
-Cyan pigment PB15: 3 aqueous dispersion: 18.8 g
(Emacol SF Blue H524F (trade name; manufactured by Sanyo Dye Co., Ltd., solid content: 26% by mass))
・ Distilled water: 24.1 g
連続相の調製
　下記成分を混合して連続相を準備した。
・界面活性剤ＫＦ－６０２８（商品名；信越化学工業社製）：　３．５ｇ
・シリコンオイルＫＦ－９６－２ｃｓ（商品名；信越化学工業社製）：　３４６．５ｇ Preparation of continuous phase The following components were mixed to prepare a continuous phase.
Surfactant KF-6028 (trade name; manufactured by Shin-Etsu Chemical Co., Ltd.): 3.5 g
・ Silicon oil KF-96-2cs (trade name; manufactured by Shin-Etsu Chemical Co., Ltd.): 346.5 g
粒子作製
　上記分散相５０ｇと、上記連続相３５０ｇとを混合し、内歯式卓上分散機ＲＯＢＯＭＩＣＳ（商品名；特殊機化工業社製）を用い回転数１０，０００ｒｐｍ、温度３０℃で１０分間乳化を行った。その結果、乳化液滴径が約２μｍの乳化液を得た。これをロータリーエバポレーターにより真空度２０ｍｂａｒ、水浴温度４０℃で１８時間乾燥を行った。
　得られた粒子懸濁液を６，０００ｒｐｍで１５分間遠心分離し，上澄み液を除去した後、シリコーンオイルＫＦ－９６－２ＣＳを用いて再分散させる洗浄工程を３回繰り返した。このようにしてコア粒子６ｇを得た。ＳＥＭ画像解析した結果、平均粒径は０．６μｍであった。 Particle preparation 50 g of the above dispersed phase and 350 g of the above continuous phase are mixed, and emulsified for 10 minutes at a rotational speed of 10,000 rpm and a temperature of 30 ° C. using an internal tooth tabletop dispersing machine ROBOMICS (trade name; manufactured by Tokushu Kika Kogyo Co., Ltd.) Went. As a result, an emulsified liquid having an emulsified droplet diameter of about 2 μm was obtained. This was dried by a rotary evaporator at a vacuum of 20 mbar and a water bath temperature of 40 ° C. for 18 hours.
The obtained particle suspension was centrifuged at 6,000 rpm for 15 minutes, the supernatant was removed, and the washing step of redispersing with silicone oil KF-96-2CS was repeated three times. In this way, 6 g of core particles were obtained. As a result of SEM image analysis, the average particle size was 0.6 μm.
２）シェル形成（コアセルベーション法）
シェル樹脂の合成
　下記成分を混合し、窒素下で７０℃、６時間重合を行なった。
・サイラプレーン(SILAPLANE) ＦＭ－０７２１（商品名；チッソ社製）：　５０ｇ
・ヒドロキシエチルメタクリレート（アルドリッチ社製）：　３２ｇ
・フェノキシ基を含むモノマーＡＭＰ－１０Ｇ（商品名；新中村化学社製）：　１８ｇ
・ブロックイソシアネート基を含むモノマー：　２ｇ
　（カレンズＭＯＩ－ＢＰ（登録商標；昭和電工社製））
・イソプロピルアルコール（関東化学社製）：　２００ｇ
・重合開始剤ＡＩＢＮ：　０．２ｇ
　（２，２’－アゾビスイソブチロニトリル、商品名、アルドリッチ社製） 2) Shell formation (coacervation method)
Synthesis of Shell Resin The following components were mixed and polymerized at 70 ° C. for 6 hours under nitrogen.
・ SILAPLANE FM-0721 (trade name; manufactured by Chisso Corporation): 50g
・ Hydroxyethyl methacrylate (Aldrich): 32g
Monomer AMP-10G containing a phenoxy group (trade name; manufactured by Shin-Nakamura Chemical Co., Ltd.): 18 g
・ Monomer containing a blocked isocyanate group: 2 g
(Karenz MOI-BP (registered trademark; manufactured by Showa Denko))
・ Isopropyl alcohol (Kanto Chemical Co., Inc.): 200g
-Polymerization initiator AIBN: 0.2g
(2,2'-azobisisobutyronitrile, trade name, manufactured by Aldrich)
　そして、生成物を、シクロヘキサンを再沈殿溶媒として精製及び乾燥しシェル樹脂を得た。このシェル樹脂２ｇをｔ－ブタノール溶媒２０ｇに溶解し、シェル樹脂溶液を作製した。 The product was purified and dried using cyclohexane as a reprecipitation solvent to obtain a shell resin. 2 g of this shell resin was dissolved in 20 g of t-butanol solvent to prepare a shell resin solution.
シェル樹脂による粒子被覆
　上記コア粒子１ｇを２００ｍＬのナスフラスコに取り、シリコンオイルＫＦ－９６－２ｃｓを１５ｇ加え、超音波を加えながら撹拌分散した。これに、ｔ－ブタノールを７．５ｇ、上記シェル樹脂溶液２２ｇ、シリコンオイルＫＦ－９６－２ｃｓ（商品名；信越化学工業社製）１２．５ｇを順次加えた。投入速度は全て２ｍＬ／ｓとした。上記ナスフラスコをロータリーエバポレーターに接続し、真空度２０ｍｂａｒ、水浴温度５０℃で１時間、ｔ－ブタノール除去を行った。 Particle coating with shell resin 1 g of the above core particles was placed in a 200 mL eggplant flask, 15 g of silicone oil KF-96-2cs was added, and the mixture was stirred and dispersed while applying ultrasonic waves. To this, 7.5 g of t-butanol, 22 g of the above shell resin solution, and 12.5 g of silicone oil KF-96-2cs (trade name; manufactured by Shin-Etsu Chemical Co., Ltd.) were sequentially added. The input speed was all 2 mL / s. The eggplant flask was connected to a rotary evaporator, and t-butanol was removed at a vacuum of 20 mbar and a water bath temperature of 50 ° C. for 1 hour.
　これをさらに撹拌しながらオイルバス中で加温した。まず１００℃で１時間加温し、残留水分と残留するｔ－ブタノールを除いた後、続けて１３０℃で１．５時間の加熱を行い、ブロックイソシアネート基のブロック基を脱離させ、シェル樹脂の架橋反応を行った。
　冷却後、得られた粒子懸濁液を６，０００ｒｐｍで１５分間遠心分離し，上澄み液を除去した後、シリコーンオイルＫＦ－９６－２ｃｓ（信越化学工業社製）を用いて再分散させる洗浄工程を３回繰り返した。このようにしてシアン粒子Ｃ１を０．６ｇ得た。 This was further heated in an oil bath with stirring. First, after heating at 100 ° C. for 1 hour to remove residual moisture and residual t-butanol, heating was continued at 130 ° C. for 1.5 hours to remove the blocking group of the blocked isocyanate group, and the shell resin The crosslinking reaction was performed.
After cooling, the resulting particle suspension is centrifuged at 6,000 rpm for 15 minutes, the supernatant is removed, and then re-dispersed using silicone oil KF-96-2cs (manufactured by Shin-Etsu Chemical Co., Ltd.). Was repeated three times. In this way, 0.6 g of cyan particles C1 was obtained.
赤色粒子Ｒ１の作製
分散液Ａ－１Ａの調製
　下記成分を混合し、１０ｍｍΦのジルコニアボールにてボールミル粉砕を２０時間実施
して分散液Ａ－１Ａを調製した。
・メタクリル酸メチル（アルドリッチ社製）：　５３ｇ
・メタクリル酸２－（ジエチルアミノ）エチル（アルドリッチ社製）：　０．３ｇ
・赤色顔料Ｒｅｄ３０９０（商品名；山陽色素社製）：　１．５ｇ Preparation of Red Particle R1 Preparation of Dispersion A-1A The following components were mixed and ball milled with 10 mmφ zirconia balls for 20 hours to prepare Dispersion A-1A.
・ Methyl methacrylate (Aldrich): 53g
-2- (Diethylamino) ethyl methacrylate (manufactured by Aldrich): 0.3 g
-Red pigment Red 3090 (trade name; manufactured by Sanyo Dye): 1.5 g
分散液Ａ－１Ｂの調製
　下記成分を混合し、上記と同様にボールミルにて微粉砕して炭酸カルシウム分散液Ａ－
１Ｂを調製した。
・炭酸カルシウム：　４０ｇ
・水：　６０ｇ Preparation of Dispersion A-1B The following components were mixed, and finely pulverized with a ball mill in the same manner as described above to obtain a calcium carbonate dispersion A-
1B was prepared.
・ Calcium carbonate: 40g
・ Water: 60g
混合液Ａ－１Ｃの調製
　下記成分を混合し、超音波機で脱気を１０分間おこない、ついで乳化機で攪拌して混合
液Ａ－１Ｃを調製した。
・炭酸カルシウム分散液Ａ－１Ｂ：　４ｇ
・２０％食塩水：　６０ｇ Preparation of liquid mixture A-1C The following components were mixed, degassed with an ultrasonic machine for 10 minutes, and then stirred with an emulsifier to prepare liquid mixture A-1C.
・ Calcium carbonate dispersion A-1B: 4g
・ 20% saline solution: 60g
着色粒子の調製
　下記成分を混合後、超音波機で脱気を１０分行った。
・分散液Ａ－１Ａ：　２０ｇ
・ジメタクリル酸エチレングリコール：　０．６ｇ
・重合開始剤Ｖ６０１：　０．２ｇ
　（Ｄｉｍｅｔｈｙｌ　２，２’－ａｚｏｂｉｓ（２－ｍｅｔｈｙｌｐｒｏｐｉｏｎａｔｅ）；商品名、和光純薬工業社製） Preparation of colored particles After mixing the following components, deaeration was performed with an ultrasonic machine for 10 minutes.
・ Dispersion A-1A: 20 g
・ Ethylene glycol dimethacrylate: 0.6g
-Polymerization initiator V601: 0.2g
(Dimethyl 2,2′-azobis (2-methylpropionate); trade name, manufactured by Wako Pure Chemical Industries, Ltd.)
　これを混合液Ａ－１Ｃに加え、乳化機で乳化を実施した。次にこの乳化液をフラスコにいれ、減圧脱気を充分行い、窒素ガスで封入した。次に６５℃で１５時間反応させ粒子を調製した。冷却後、粒子を濾過し、得られた粒子粉をイオン交換水中に分散させ、塩酸水で炭酸カルシウムを分解させ、ろ過を行った。充分な蒸留水で洗浄し、目開き：１５μｍ、１０μｍのナイロン篩にかけ、粒度を揃えた。得られた粒子は、体積平均粒径１３μｍであった。 This was added to the mixed solution A-1C and emulsified with an emulsifier. Next, this emulsified liquid was put into a flask, sufficiently degassed under reduced pressure, and sealed with nitrogen gas. Next, it was reacted at 65 ° C. for 15 hours to prepare particles. After cooling, the particles were filtered, and the obtained particle powder was dispersed in ion-exchanged water, and calcium carbonate was decomposed with hydrochloric acid water, followed by filtration. After washing with sufficient distilled water, the openings were passed through nylon sieves having a mesh size of 15 μm and 10 μm to make the particle sizes uniform. The obtained particles had a volume average particle size of 13 μm.
４級アンモニウム化処理
　得られた粒子をシリコーンオイルＫＦ９６－１ｃｓ（信越化学工業社製）に分散し、臭化ドデシル（４級化剤）を、粒子の調整に用いたメタクリル酸２－（ジエチルアミノ）エチルと等モル量加え、９０℃で６時間加熱した。
　冷却後、この分散液を多量のシリコーンオイルにて洗浄し、減圧乾燥させることにより
赤色粒子Ｒ１を得た。この粒子に含まれる樹脂のガラス転移温度は１４５℃であった。 Quaternary ammoniumation treatment The obtained particles were dispersed in silicone oil KF96-1cs (manufactured by Shin-Etsu Chemical Co., Ltd.), and dodecyl bromide (quaternizing agent) was used to prepare particles 2- (diethylamino) methacrylate. An equimolar amount with ethyl was added, and the mixture was heated at 90 ° C. for 6 hours.
After cooling, this dispersion was washed with a large amount of silicone oil and dried under reduced pressure to obtain red particles R1. The glass transition temperature of the resin contained in the particles was 145 ° C.
白色粒子Ｗ１の作製
１）コア粒子の作製
溶液Ａ１（連続相）の調製
　以下の材料を混合し、ラジカル溶液重合（５５℃で６時間）にて高分子分散剤Ｅ１を合成した。
・サイラプレーンＦＭ－０７１１：　３６ｇ
　（商品名；チッソ社製、重量平均分子量Ｍｎ＝１，０００）
・メタクリル酸（アルドリッチ社製）：　０．３５ｇ
・シリコーンオイルＫＦ－９６－２ｃｓ（信越化学工業社製）：　４０ｇ
・重合開始剤Ｖ－６５（和光純薬工業社製）：　０．０６ｇ
　生成物を重合反溶成分が３ｇなるようにシリコーンオイルＫＦ－９６－２ｃｓ（信越化学工業社製）を用いて希釈し、高分子分散剤Ｅ１を含む溶液Ａ１（連続相）を調整した。 Preparation of white particles W1 1) Preparation of core particle solution A1 (continuous phase) The following materials were mixed and a polymer dispersant E1 was synthesized by radical solution polymerization (at 55 ° C. for 6 hours).
・ Silaplane FM-0711: 36g
(Product name: manufactured by Chisso Corporation, weight average molecular weight Mn = 1,000)
・ Methacrylic acid (manufactured by Aldrich): 0.35 g
・ Silicone oil KF-96-2cs (manufactured by Shin-Etsu Chemical Co., Ltd.): 40g
・ Polymerization initiator V-65 (manufactured by Wako Pure Chemical Industries): 0.06 g
The product was diluted with silicone oil KF-96-2cs (manufactured by Shin-Etsu Chemical Co., Ltd.) so that the amount of the polymerization anti-soluble component was 3 g, and a solution A1 (continuous phase) containing the polymer dispersant E1 was prepared.
溶液Ｂ１（分散相）の調製
　スチレンアクリル系樹脂Ｘ－１２０２Ｌ（商品名；星光ＰＭＣ社製）１０ｇ、二酸化チタンＴＴＯ－５５Ａ（商品名；石原産業社製）１０ｇ、および蒸留水９０ｇを混合したものにジルコニアビーズを加え、ロッキングミルで１時間分散処理を行い、分散相Ｂ１とした。 Preparation of solution B1 (dispersed phase) A mixture of 10 g of styrene acrylic resin X-1202L (trade name; manufactured by Seiko PMC), 10 g of titanium dioxide TTO-55A (trade name; manufactured by Ishihara Sangyo Co., Ltd.), and 90 g of distilled water Zirconia beads were added to the mixture, and dispersion treatment was performed for 1 hour with a rocking mill to obtain dispersed phase B1.
乳化および液中乾燥工程
　溶液Ａ１（連続相）８０ｇと、溶液Ｂ１（分散相）２０ｇとを混合して、オムニホモジナイザーＧＬＨ－１１５（商品名；ヤマト科学（株）製）を用いて２０，０００ｒｐｍで１０分間乳化を行い乳化液を調製した。
　次に、得られた乳化液をナスフラスコに入れ、撹拌しながらエバポレーターにて６５℃、１０ｍＰａに加熱減圧することで水を除去し、二酸化チタン粒子がシリコーンオイル中に分散された粒子分散液を得た。得られた分散液を遠心分離を用いて沈降させ、上澄みを除去し、トルエンを加えて粒子固形分濃度２０質量％となるように調製し、粒子トルエン分散液Ｃ１を得た。 Emulsification and Submerged Drying Step 80 g of solution A1 (continuous phase) and 20 g of solution B1 (dispersed phase) are mixed and 20,000 rpm using an omni homogenizer GLH-115 (trade name; manufactured by Yamato Scientific Co., Ltd.). Was emulsified for 10 minutes to prepare an emulsion.
Next, the obtained emulsion is put into an eggplant flask, water is removed by heating and reducing to 65 ° C. and 10 mPa with an evaporator while stirring, and a particle dispersion in which titanium dioxide particles are dispersed in silicone oil is obtained. Obtained. The obtained dispersion was sedimented using centrifugation, the supernatant was removed, and toluene was added to prepare a particle solid concentration of 20% by mass to obtain a particle toluene dispersion C1.
２）シェル化工程
シェル樹脂の合成
・スチレン（和光純薬社製）：　７０ｇ
・サイラプレーンＦＭ－０７２１：　２５ｇ
　（商品名；チッソ社製、重量平均分子量Ｍｗ＝５０００）
・メタクリル酸（東京化成品工業社製）：　５ｇ
・ラウロイルパーオキサイド（アルドリッチ社製）：　１ｇ
・トルエン（関東化学社製）：　１００ｇ
　上記組成で各材料を混合し、７５℃で６時間加熱した後、イソプロピルアルコール（関東化学社製）中に滴下し、再沈殿法により精製し、白色の固体を得た。得られた樹脂の重量平均分子量分子量Ｍｗ＝３００００であった。 2) Shelling process Synthesis of shell resin / Styrene (Wako Pure Chemical Industries): 70 g
・ Silaplane FM-0721: 25g
(Product name: manufactured by Chisso Corporation, weight average molecular weight Mw = 5000)
・ Methacrylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.): 5g
・ Lauroyl peroxide (manufactured by Aldrich): 1 g
・ Toluene (Kanto Chemical Co., Inc.): 100g
After mixing each material with the said composition and heating at 75 degreeC for 6 hours, it was dripped in isopropyl alcohol (made by Kanto Chemical Co., Inc.), and refine | purified by the reprecipitation method, and white solid was obtained. The obtained resin had a weight average molecular weight and a molecular weight Mw of 30000.
シェル樹脂による粒子被覆
・上記シェル樹脂：　１０ｇ
・粒子トルエン分散液Ｃ１（粒子固形分濃度２０質量％）：　５０ｇ
　上記組成で各材料を混合し、それにシリコーンオイルＫＦ－９６Ｌ－２ｃｓ（信越化学工業社製）を２００ｇ滴下しシェル樹脂を析出させた。その後、エバポレーターを用いて６０℃、２０ｍｂａｒ下でトルエンを除去することで、シェル樹脂で被覆された酸化チタンよりなる、白色粒子Ｗ１の分散液を得た。
　白色粒子Ｗ１の体積平均粒径は２５０ｎｍであった。白色粒子Ｗ１の酸化チタン含有量（顔料含有量）は４０質量％であった。 Particle coating with shell resin ・ Shell resin: 10g
-Particle toluene dispersion C1 (particle solid content concentration 20% by mass): 50 g
Each material was mixed with the above composition, and 200 g of silicone oil KF-96L-2cs (manufactured by Shin-Etsu Chemical Co., Ltd.) was added dropwise to deposit a shell resin. Then, the dispersion liquid of the white particle W1 which consists of a titanium oxide coat | covered with shell resin was obtained by removing toluene using an evaporator under 60 degreeC and 20 mbar.
The volume average particle diameter of the white particles W1 was 250 nm. The titanium oxide content (pigment content) of the white particles W1 was 40% by mass.
白色粒子Ｗ２～Ｗ１０の作製
　白色粒子Ｗ１の作製において、表１に従って、溶液Ｂ１（分散相）に加えるスチレンアクリル系樹脂Ｘ－１２０２Ｌ（商品名；星光ＰＭＣ社製）と、二酸化チタンＴＴＯ－５５Ａ（商品名；石原産業社製）の比を変えることにより、白色粒子中の酸化チタン含有量を調整した。また、オムニホモジナイザーの回転数および分散時間を変更することで、得られる白色粒子の体積平均粒径を調整した。
　このようにして、白色粒子Ｗ２～Ｗ８の分散液を得た。 Preparation of white particles W2 to W10 In preparation of white particles W1, in accordance with Table 1, styrene acrylic resin X-1220L (trade name; manufactured by Seiko PMC) to be added to solution B1 (dispersed phase) and titanium dioxide TTO-55A ( The titanium oxide content in the white particles was adjusted by changing the ratio of the trade name (made by Ishihara Sangyo Co., Ltd.). Moreover, the volume average particle diameter of the white particles obtained was adjusted by changing the rotation speed and dispersion time of the omnihomogenizer.
In this way, a dispersion of white particles W2 to W8 was obtained.
白色粒子Ｗ１１～Ｗ１２の作製
　白色粒子Ｗ１の作製において、溶液Ｂ１（分散相）に加えるスチレンアクリル系樹脂Ｘ－１２０２Ｌ（商品名；星光ＰＭＣ社製）をスチレンアクリル系樹脂Ｘ－３４５（商品名；星光ＰＭＣ社製）、ポリビニルピロリドン（和光純薬工業社製、商品名；ＰＶＰ　Ｋ３０）にそれぞれ変更することで白色粒子Ｗ１１～Ｗ１２の分散液の分散液を得た。 Production of white particles W11 to W12 In production of white particles W1, styrene acrylic resin X-1202L (trade name; manufactured by Seiko PMC) added to solution B1 (dispersed phase) was replaced with styrene acrylic resin X-345 (trade name; The dispersion liquid of white particles W11 to W12 was obtained by changing to Starlight PMC) and polyvinylpyrrolidone (trade name; PVP K30, manufactured by Wako Pure Chemical Industries, Ltd.), respectively.
白色粒子Ｗ１３の作製
　還流冷却管を取り付けた５００ｍｌ三口フラスコに、２－ビニルナフタレン（新日鐵化学社製）を４５ｇ、サイラプレーンＦＭ－０７２１（商品名；チッソ社製）を４５ｇ、シリコーンオイルＫＦ　－９６Ｌ－１ｃｓ（商品名；信越化学工業社製）を２４０ｇ加えた。混合液を６５℃に昇温した後、窒素ガスによるバブリングを１５分間行い、開始剤として過酸化ラウロイル（アルドリッチ社製）を２．３ｇ投入した。窒素雰囲気下にて６５℃、２４時間の重合を行った。
　得られた粒子懸濁液を８，０００ｒｐｍで１０分間遠心分離し，上澄み液を除去した後尾，シリコーンオイルＫＦ－９６－２ｃｓ（信越化学工業社製）を用いて再分散させる洗浄工程を３回繰り返した。最後にシリコーンオイルにて粒子固形分濃度４０質量％に調製して、白色粒子Ｗ１３の分散液を得た。白色粒子Ｗ９の体積平均粒径は３９８ｎｍであった。 Production of white particles W13 In a 500 ml three-necked flask equipped with a reflux condenser, 45 g of 2-vinylnaphthalene (manufactured by Nippon Steel Chemical Co., Ltd.), 45 g of Silaplane FM-0721 (trade name; manufactured by Chisso Corporation), silicone oil KF 240 g of -96L-1cs (trade name; manufactured by Shin-Etsu Chemical Co., Ltd.) was added. After raising the temperature of the mixture to 65 ° C., bubbling with nitrogen gas was performed for 15 minutes, and 2.3 g of lauroyl peroxide (manufactured by Aldrich) was added as an initiator. Polymerization was performed at 65 ° C. for 24 hours under a nitrogen atmosphere.
The resulting particle suspension is centrifuged at 8,000 rpm for 10 minutes, the supernatant is removed, and the washing process is performed three times by re-dispersing with silicone oil KF-96-2cs (manufactured by Shin-Etsu Chemical Co., Ltd.). Repeated. Finally, the particle solid content concentration was adjusted to 40% by mass with silicone oil to obtain a dispersion of white particles W13. The volume average particle diameter of the white particles W9 was 398 nm.
表示用粒子分散液１～１３（ＣＲＷ混合粒子分散液）の調製
　シアン粒子Ｃ１と赤色粒子Ｒ１と白色粒子Ｗ１とを、固形分でシアン粒子Ｃ１が０．１ｇ、赤色粒子Ｒ１が１．３ｇ、白色粒子Ｗ１が２．０ｇとなるように秤量して混合し、液量が１０ｇとなるようにシリコーンオイルＫＦ－９６Ｌ－２ｃｓ（信越化学工業社製）を加え、超音波撹拌して表示用粒子分散液１を調製した。
　同様に、白色粒子Ｗ１に代えて、白色粒子Ｗ２～Ｗ１３を用いて、各々表示用粒子分散液２～１３を調製した。
　なお、分散媒に相当する「シリコーンオイルＫＦ－９６Ｌ－２ｃｓ（信越化学工業社製）」の粘度は、２ｍＰａ・ｓであった。 Preparation of Display Particle Dispersions 1 to 13 (CRW Mixed Particle Dispersion) Cyan particles C1, red particles R1, and white particles W1 are solid particles of cyan particles C1 of 0.1 g, red particles R1 of 1.3 g, Weigh and mix so that white particle W1 is 2.0 g, add silicone oil KF-96L-2cs (manufactured by Shin-Etsu Chemical Co., Ltd.) so that the liquid volume is 10 g, and ultrasonically stir to display particles. Dispersion 1 was prepared.
Similarly, display particle dispersions 2 to 13 were prepared using white particles W2 to W13 in place of the white particles W1, respectively.
The viscosity of “silicone oil KF-96L-2cs (manufactured by Shin-Etsu Chemical Co., Ltd.)” corresponding to the dispersion medium was 2 mPa · s.
評価セル１～１３の作製
高分子化合物Ａの合成
　下記成分を、窒素下で７０℃、６時間重合を行なった。
・サイラプレーンＦＭ－０７２１：　５ｇ
　（商品名；チッソ社製、重量平均分子量Ｍｗ＝５０００）
・フェノキシエチレングリコールアクリレート：　５ｇ
　（ＮＫエステルＡＭＰ－１０Ｇ（商品名、新中村化学社製））
・ヒドロキシエチルメタクリレート（和光純薬社製）：　９０ｇ
・イソプロピルアルコール（ＩＰＡ）：　３００ｇ
・ＡＩＢＮ（２，２－アゾビスイソブチルニトリル）：　１ｇ Preparation of Evaluation Cells 1 to 13 Synthesis of Polymer Compound A The following components were polymerized under nitrogen at 70 ° C. for 6 hours.
・ Silaplane FM-0721: 5g
(Product name: manufactured by Chisso Corporation, weight average molecular weight Mw = 5000)
・ Phenoxyethylene glycol acrylate: 5g
(NK ester AMP-10G (trade name, manufactured by Shin-Nakamura Chemical Co., Ltd.))
・ Hydroxyethyl methacrylate (Wako Pure Chemical Industries, Ltd.): 90g
・ Isopropyl alcohol (IPA): 300 g
AIBN (2,2-azobisisobutylnitrile): 1 g
　得られた生成物を、ヘキサンを再沈殿溶媒として精製、乾燥し高分子化合物Ａを得た。 The resulting product was purified using hexane as a reprecipitation solvent and dried to obtain polymer compound A.
評価用セルの作製
　上記高分子化合物Ａを固形分濃度が４ｗｔ％になるようにＩＰＡ（イソプロピルアルコール）に溶解した。電極として厚さ５０ｎｍのＩＴＯ（酸化スズインジウム）をスパッタリング法で成膜したガラス基板上に、上記高分子化合物Ａの溶液をスピンコートして、１３０℃で１時間乾燥させて、膜厚が１００ｎｍの表面層を形成した。 Preparation of Evaluation Cell The polymer compound A was dissolved in IPA (isopropyl alcohol) so that the solid content concentration was 4 wt%. A solution of the polymer compound A is spin-coated on a glass substrate on which ITO (indium tin oxide) having a thickness of 50 nm is formed as an electrode by a sputtering method, and dried at 130 ° C. for 1 hour. A surface layer was formed.
　このようにして作製した表面層付きＩＴＯ基板を２枚用意し、表示基板及び背面基板
とした。厚さ５０μｍのテフロン（登録商標）シートをスペーサーとして、互いの表面層を対向させて背面基板上に表示基板を重ね合わせて、クリップにて固定した。このようにして作製した評価用の空セルに表示用粒子分散液１を注入して、評価セル１を作製した。
　同様に、表示用粒子分散液１に代えて、表示用粒子分散液２～１３を用いて、各々評価セル２～１３を作製した。 Two ITO substrates with a surface layer thus prepared were prepared and used as a display substrate and a back substrate. Using a Teflon (registered trademark) sheet having a thickness of 50 μm as a spacer, the display substrate was superimposed on the back substrate with the surface layers facing each other, and fixed with clips. An evaluation cell 1 was produced by injecting the display particle dispersion 1 into the empty cell for evaluation thus produced.
Similarly, evaluation cells 2 to 13 were produced using the display particle dispersions 2 to 13 instead of the display particle dispersion 1, respectively.
　以下、各評価セルについて、表１に一覧にして示す。
　なお、表１において、一般式（１）の「６ｋＴ/（πｄ３（ρｐ－ρｓ）ｇ）」値の計算は、各評価セルに適用した白色粒子の体積平均粒径、白色粒子の比重、及び分散媒としてのシリコーンオイルの比重から算出した。
　なお、白色粒子の比重は、酸化チタンの含有量、酸化チタンの比重４．２６ｇ／ｃｍ３、及び樹脂の比重１．２ｇ／ｃｍ３から算出した。また、シリコーンオイルの比重は０．８７８ｇ／ｃｍ３として計算した。 The evaluation cells are listed below in Table 1.
In Table 1, the calculation of the “6 kT / (πd 3 (ρp−ρs) g)” value of the general formula (1) is based on the volume average particle diameter of the white particles applied to each evaluation cell, the specific gravity of the white particles, And the specific gravity of silicone oil as a dispersion medium.
Incidentally, the specific gravity of the white particles, titanium oxide content, specific gravity of 4.26 g / cm 3 of titanium oxide, and was calculated from the specific gravity of 1.2 g / cm 3 of resin. The specific gravity of silicone oil was calculated as 0.878 g / cm 3 .
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
白表示反射率および応答時間の評価
　作製した評価用セルを用いて、表面電極がプラスとなるように電極間に１５Ｖの電位差を５秒間印加したところ、正帯電のシアン粒子と正帯電の赤色粒子はマイナス側電極、すなわち、背面電極側へ移動し、表示基板側から観察すると白色が観察される。この時の反射濃度を分光測色計（Ｘ－Ｒｉｔｅ社製Ｘ－Ｒｉｔｅ９３９（商品名））により測定し、白表示の反射率とした。
　次に、表面電極がマイナスとなるように電極間に１５Ｖの電位差を５秒間印加した。分散された正帯電のシアン粒子と正帯電の赤色粒子はマイナス側電極、すなわち、表面電極側へ移動し、表示基板側から観察すると黒色が観察された。この時の反射濃度を分光測色計（Ｘ－Ｒｉｔｅ社製Ｘ－Ｒｉｔｅ９３９）により測定し、Ｄｍａｘとした。白表示から黒表示に切り替えた際に、反射濃度が変化する様子を各次時間で測定し、Ｄｍａｘの９０％の濃度に達する時間を応答時間とした。 Evaluation of white display reflectance and response time Using the prepared evaluation cell, a potential difference of 15 V was applied between the electrodes so that the surface electrode was positive, and positively charged cyan particles and positively charged red particles were applied. Moves to the negative side electrode, that is, the back electrode side, and when viewed from the display substrate side, white is observed. The reflection density at this time was measured with a spectrocolorimeter (X-Rite 939 (trade name) manufactured by X-Rite) to obtain the reflectance of white display.
Next, a potential difference of 15 V was applied between the electrodes for 5 seconds so that the surface electrode was negative. The dispersed positively charged cyan particles and positively charged red particles moved to the negative electrode, that is, the surface electrode side, and when observed from the display substrate side, black was observed. The reflection density at this time was measured with a spectrocolorimeter (X-Rite 939 manufactured by X-Rite Co., Ltd.) to obtain Dmax. When switching from white display to black display, the state of reflection density changing was measured at each next time, and the time to reach a density of 90% of Dmax was taken as the response time.
白色粒子沈降の評価
　白色粒子を固形分で０．５ｇとなるように秤量し、液量が１０ｇとなるようにシリコーンオイルＫＦ－９６Ｌ－２ｃｓ（信越化学工業社製）を加え、超音波撹拌した沈降評価用分散液を調製した。評価用セルの表示用粒子分散液を沈降評価用分散液に変更した沈降評価セルを作製した。これらセルを縦置きにし、５日放置後の白色粒子の沈降に様子を観察し評価した。
Ａ：白色粒子の沈降なし
Ｂ：上部の液がわずかに薄くなっている
Ｃ：白色粒子が沈降し、白部と透明部に明確に分離している Evaluation of white particle sedimentation White particles were weighed to a solid content of 0.5 g, and silicone oil KF-96L-2cs (manufactured by Shin-Etsu Chemical Co., Ltd.) was added so that the liquid volume was 10 g, followed by ultrasonic stirring. A dispersion for sedimentation evaluation was prepared. A sedimentation evaluation cell was prepared by changing the display particle dispersion of the evaluation cell to a dispersion for sedimentation evaluation. These cells were placed vertically, and the appearance of white particles settled after standing for 5 days was observed and evaluated.
A: No sedimentation of white particles B: The upper liquid is slightly thinner C: White particles settle and are clearly separated into white and transparent portions
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000004
　表２の結果から、白色粒子において顔料（酸化チタン）含有量を増やすことで、反射率は高くなるが、沈降安定性および応答速度が悪化してしまうことがわかる。
　また、表示用粒子分散液において、白色粒子の体積平均粒径及び顔料（酸化チタン）含有量を所定範囲とした上で、一般式（１）を満たすことにより、優れた高白表示反射率、優れた白色粒子の沈降安定性が実現されることがわかる。また、迅速な表示応答速度を実現できることもわかる。
　また、分散媒に相当する「シリコーンオイルＫＦ－９６Ｌ－２ｃｓ（信越化学工業社製）」の粘度が５ｍＰａ・ｓ以下と低粘度であっても、優れた白色粒子の沈降安定性が実現されることがわかる。 From the results in Table 2, it can be seen that increasing the pigment (titanium oxide) content in the white particles increases the reflectivity but deteriorates the sedimentation stability and response speed.
Further, in the display particle dispersion, the volume average particle size of the white particles and the pigment (titanium oxide) content are within the predetermined ranges, and by satisfying the general formula (1), an excellent high white display reflectance, It can be seen that excellent white particle sedimentation stability is achieved. It can also be seen that a quick display response speed can be realized.
Further, even when the viscosity of “silicone oil KF-96L-2cs (manufactured by Shin-Etsu Chemical Co., Ltd.)” corresponding to the dispersion medium is as low as 5 mPa · s or less, excellent sedimentation stability of white particles is realized. I understand that.
実施例２：ＹＭＣＷ混合系
黄色粒子Ｙ１の作製
分散液Ａ－１Ａの調製
　下記成分を混合し、１０ｍｍΦのジルコニアボールにてボールミル粉砕を２０時間実施して分散液Ａ－１Ａを調製した。
・メタクリル酸メチル：　５３ｇ
・メタクリル酸２－（ジエチルアミノ）エチル：　０．３ｇ
・黄色顔料（ＦＹ７４１６：商品名、山陽色素社製）：　１．５ｇ Example 2: Preparation of YMCW mixed system yellow particles Y1 Preparation of dispersion A-1A The following components were mixed and ball milling was performed for 20 hours with zirconia balls having a diameter of 10 mm to prepare dispersion A-1A.
・ Methyl methacrylate: 53g
・ 2- (diethylamino) ethyl methacrylate: 0.3 g
・ Yellow pigment (FY7416: trade name, manufactured by Sanyo Color Co., Ltd.): 1.5 g
分散液Ａ－１Ｂの調製
　下記成分を混合し、上記と同様にボールミルにて微粉砕して炭酸カルシウム分散液Ａ－１Ｂを調製した。
・炭酸カルシウム：　４０ｇ
・水：　６０ｇ Preparation of Dispersion A-1B The following components were mixed and finely pulverized with a ball mill in the same manner as described above to prepare a calcium carbonate dispersion A-1B.
・ Calcium carbonate: 40g
・ Water: 60g
混合液Ａ－１Ｃの調製
　下記成分を混合し、超音波機で脱気を１０分間行い、ついで乳化機で攪拌して混合液Ａ－１Ｃを調製した。
・炭酸カルシウム分散液Ａ－１Ｂ：　４ｇ
・２０％食塩水：　６０ｇ Preparation of liquid mixture A-1C The following components were mixed, degassed with an ultrasonic machine for 10 minutes, and then stirred with an emulsifier to prepare liquid mixture A-1C.
・ Calcium carbonate dispersion A-1B: 4g
・ 20% saline solution: 60g
着色粒子の調製
　下記成分を混合後、超音波機で脱気を１０分行った。
・分散液Ａ－１Ａ：　２０ｇ
・ジメタクリル酸エチレングリコール：　０．６ｇ
・重合開始剤Ｖ６０１：　０．２ｇ
　（商品名、和光純薬工業社製；Ｄｉｍｅｔｈｙｌ　２，２’－ａｚｏｂｉｓ（２－ｍｅｔｈｙｌｐｒｏｐｉｏｎａｔｅ）
　これを混合液Ａ－１Ｃに加え、乳化機で乳化を実施した。次にこの乳化液をフラスコにいれ、減圧脱気を充分行い、窒素ガスで封入した。次に６５℃で１５時間反応させ粒子を調製した。冷却後、粒子を濾過し、得られた粒子粉をイオン交換水中に分散させ、塩酸水で炭酸カルシウムを分解させ、ろ過を行った。充分な蒸留水で洗浄し、目開き：１５μｍ、１０μｍのナイロン篩にかけ、粒度を揃えた。得られた粒子は、体積平均粒径１３μｍであった。 Preparation of colored particles After mixing the following components, deaeration was performed with an ultrasonic machine for 10 minutes.
・ Dispersion A-1A: 20 g
・ Ethylene glycol dimethacrylate: 0.6g
-Polymerization initiator V601: 0.2g
(Trade name, manufactured by Wako Pure Chemical Industries, Ltd .; Dimethyl 2,2'-azobis (2-methylpropionate)
This was added to the mixed solution A-1C and emulsified with an emulsifier. Next, this emulsified liquid was put into a flask, sufficiently degassed under reduced pressure, and sealed with nitrogen gas. Next, it was reacted at 65 ° C. for 15 hours to prepare particles. After cooling, the particles were filtered, and the obtained particle powder was dispersed in ion-exchanged water, and calcium carbonate was decomposed with hydrochloric acid water, followed by filtration. After washing with sufficient distilled water, the openings were passed through nylon sieves having a mesh size of 15 μm and 10 μm to make the particle sizes uniform. The obtained particles had a volume average particle size of 13 μm.
４級アンモニウム化処理
　得られた粒子をシリコーンオイルＫＦ９６－１ｃｓ（信越化学工業社製）に分散し、臭化ドデシル（４級化剤）を、粒子の調整に用いたメタクリル酸２－（ジエチルアミノ）エチルと等モル量加え、９０℃で６時間加熱した。
　冷却後、この分散液を多量のシリコーンオイルにて洗浄し、減圧乾燥させることにより
黄色粒子Ｙ１を得た。この粒子に含まれる樹脂のガラス転移温度は１４５℃であった。 Quaternary ammoniumation treatment The obtained particles were dispersed in silicone oil KF96-1cs (manufactured by Shin-Etsu Chemical Co., Ltd.), and dodecyl bromide (quaternizing agent) was used to prepare particles 2- (diethylamino) methacrylate. An equimolar amount with ethyl was added, and the mixture was heated at 90 ° C. for 6 hours.
After cooling, this dispersion was washed with a large amount of silicone oil and dried under reduced pressure to obtain yellow particles Y1. The glass transition temperature of the resin contained in the particles was 145 ° C.
マゼンタ粒子Ｍ１の作製
１）コア粒子の作製
分散相の調製
　下記成分を６０℃に加温しながら混合し、インク固形分濃度が１５％、乾燥後の顔料濃度が５０％となるように分散相を調製した。
・スチレンアクリル系ポリマーＸ３４５（商品名、星光ＰＭＣ社製）：　７．２ｇ
・マゼンタ顔料ＰＲ１２２の水分散液Ｅｍａｃｏｌ　ＳＦ　Ｂｌｕｅ　Ｈ５０２Ｆ　（商品名、山陽色素社製、固形分２１質量％）：　２０ｇ
・蒸留水：２２．８ｇ Preparation of magenta particles M1 1) Preparation of core particles Preparation of dispersed phase The following components were mixed while heating to 60 ° C., and the dispersed phase was adjusted so that the ink solid content concentration was 15% and the pigment concentration after drying was 50%. Was prepared.
Styrene acrylic polymer X345 (trade name, manufactured by Seiko PMC): 7.2 g
-Aqueous dispersion of magenta pigment PR122, Emacol SF Blue H502F (trade name, manufactured by Sanyo Color Co., Ltd., solid content: 21% by mass): 20 g
・ Distilled water: 22.8 g
連続相の調製
　下記成分を混合して連続相を準備した。
・界面活性剤ＫＦ－６０２８（商品名、信越化学工業社製）：　３．５ｇ
・シリコンオイルＫＦ－９６－２ｃｓ（商品名、信越化学工業社製）：　３４６．５ｇ Preparation of continuous phase The following components were mixed to prepare a continuous phase.
Surfactant KF-6028 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.): 3.5g
Silicone oil KF-96-2cs (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.): 346.5 g
粒子作製
　上記分散相５０ｇと、上記連続相３５０ｇとを混合し、内歯式卓上分散機ＲＯＢＯＭＩＣＳ（商品名、特殊機化工業社製）を用い回転数１０，０００ｒｐｍ、温度３０℃で１０分間乳化を行った。その結果、乳化液滴径が約２μｍの乳化液を得た。これをロータリーエバポレーターを用いて真空度２０ｍｂａｒ、水浴温度４０℃で１８時間乾燥を行った。
　得られた粒子懸濁液を６，０００ｒｐｍで１５分間遠心分離し、上澄み液を除去した後、シリコーンオイルＫＦ－９６－２ＣＳを用いて再分散させる洗浄工程を３回繰り返した。このようにしてコア粒子６ｇを得た。ＳＥＭ画像解析した結果、コア粒子の平均粒径は０．６μｍであった。 Particle Preparation 50 g of the above dispersed phase and 350 g of the above continuous phase are mixed, and emulsified for 10 minutes at a rotational speed of 10,000 rpm and a temperature of 30 ° C. using an internal tooth tabletop dispersing machine ROBOMICS (trade name, manufactured by Tokushu Kika Kogyo Co., Ltd.). Went. As a result, an emulsified liquid having an emulsified droplet diameter of about 2 μm was obtained. This was dried using a rotary evaporator at a vacuum degree of 20 mbar and a water bath temperature of 40 ° C. for 18 hours.
The obtained particle suspension was centrifuged at 6,000 rpm for 15 minutes, the supernatant was removed, and the washing step of redispersing with silicone oil KF-96-2CS was repeated three times. In this way, 6 g of core particles were obtained. As a result of SEM image analysis, the average particle size of the core particles was 0.6 μm.
２）シェル形成（コアセルベーション法）
シェル樹脂の合成
　下記成分を混合し、窒素下で７０℃、６時間重合を行なった。
・サイラプレーンＦＭ－０７２１（商品名；チッソ社製）：　５０ｇ
・ヒドロキシエチルメタクリレート（アルドリッチ社製）：　３２ｇ
・メタクリル酸（アルドリッチ社製）：　１４ｇ
・１Ｈ，１Ｈ，５Ｈ－オクタフルオロペンチルメタクリレート：　４ｇ
　（アルドリッチ社製）
・ブロックイソシアネート基を含むモノマー：　２ｇ
　（カレンズＭＯＩ－ＢＰ（商品名、昭和電工社製））
・イソプロピルアルコール（関東化学社製）：　２００ｇ
・重合開始剤ＡＩＢＮ：　０．２ｇ
　（２，２’－アゾビス（イソブチロニトリル））（アルドリッチ社製）
　生成物をシクロヘキサンを再沈殿溶媒として精製及び乾燥しシェル樹脂を得た。このシェル樹脂２ｇをｔ－ブタノール溶媒２０ｇに溶解し、シェル樹脂溶液を作製した。 2) Shell formation (coacervation method)
Synthesis of Shell Resin The following components were mixed and polymerized at 70 ° C. for 6 hours under nitrogen.
-Silaplane FM-0721 (trade name; manufactured by Chisso Corporation): 50 g
・ Hydroxyethyl methacrylate (Aldrich): 32g
・ Methacrylic acid (manufactured by Aldrich): 14g
・ 1H, 1H, 5H-octafluoropentyl methacrylate: 4g
(Aldrich)
・ Monomer containing a blocked isocyanate group: 2 g
(Karenz MOI-BP (trade name, manufactured by Showa Denko))
・ Isopropyl alcohol (Kanto Chemical Co., Inc.): 200g
-Polymerization initiator AIBN: 0.2g
(2,2′-azobis (isobutyronitrile)) (manufactured by Aldrich)
The product was purified and dried using cyclohexane as a reprecipitation solvent to obtain a shell resin. 2 g of this shell resin was dissolved in 20 g of t-butanol solvent to prepare a shell resin solution.
－シェル樹脂による粒子被覆－
　上記コア粒子１ｇを２００ｍＬのナスフラスコに取り、シリコンオイルＫＦ－９６－２ｃｓを１５ｇ加え、超音波を加えながら撹拌分散した。これに、ｔ－ブタノール７．５ｇ、上記シェル樹脂溶液２２ｇ、シリコンオイルＫＦ－９６－２ｃｓ（信越化学工業社製）１２．５ｇを順次加えた。投入速度は全て２ｍＬ／ｓとした。上記ナスフラスコをロータリーエバポレーターに接続し、真空度２０ｍｂａｒ、水浴温度５０℃で１時間、ｔ－ブタノール除去を行った。 -Particle coating with shell resin-
1 g of the above core particles was placed in a 200 mL eggplant flask, 15 g of silicon oil KF-96-2cs was added, and the mixture was stirred and dispersed while applying ultrasonic waves. To this, 7.5 g of t-butanol, 22 g of the above shell resin solution, and 12.5 g of silicone oil KF-96-2cs (manufactured by Shin-Etsu Chemical Co., Ltd.) were sequentially added. The input speed was all 2 mL / s. The eggplant flask was connected to a rotary evaporator, and t-butanol was removed at a vacuum of 20 mbar and a water bath temperature of 50 ° C. for 1 hour.
　これをさらに撹拌しながらオイルバス中で加温した。まず１００℃で１時間加温し、残留水分と残留するｔ－ブタノールを除いた後、続けて１３０℃で１．５時間の加熱を行い、ブロックイソシアネート基のブロック基を脱離させ、シェル樹脂の架橋反応を行った。
　冷却後、得られた粒子懸濁液を６，０００ｒｐｍで１５分間遠心分離し，上澄み液を除去した後，シリコーンオイルＫＦ－９６－２ＣＳを用いて再分散させる洗浄工程を３回繰り返した。このようにしてマゼンタ粒子Ｍ１を０．６ｇを得た。 This was further heated in an oil bath with stirring. First, after heating at 100 ° C. for 1 hour to remove residual moisture and residual t-butanol, heating was continued at 130 ° C. for 1.5 hours to remove the blocking group of the blocked isocyanate group, and the shell resin The crosslinking reaction was performed.
After cooling, the obtained particle suspension was centrifuged at 6,000 rpm for 15 minutes, the supernatant was removed, and the washing step of redispersing with silicone oil KF-96-2CS was repeated three times. In this way, 0.6 g of magenta particles M1 was obtained.
（表示用粒子分散液２－１～２－１３（ＣＲＷ混合粒子分散液）の調製）
　シアン粒子Ｃ１とマゼンタ粒子Ｍ１と黄色粒子Ｙ１と白色粒子Ｗ１とを、固形分でシアン粒子Ｃ１が０．１ｇ、マゼンタ粒子Ｍ１が０．１ｇ、黄色粒子Ｙ１が１．３ｇ、白色粒子Ｗ１が２．０ｇとなるように秤量・混合し、液量が１０ｇとなるようにシリコーンオイルＫＦ－９６Ｌ－２ｃｓ（信越化学工業社製）を加え、超音波撹拌して表示用粒子分散液２－１を調製した。
　同様に、白色粒子Ｗ１に代えて、白色粒子Ｗ２～Ｗ９を用いて、各々表示用粒子分散液２－２～２－１３を調製した。 (Preparation of display particle dispersions 2-1 to 2-13 (CRW mixed particle dispersion))
The cyan particles C1, the magenta particles M1, the yellow particles Y1, and the white particles W1 are solid particles of cyan particles C1 of 0.1 g, magenta particles M1 of 0.1 g, yellow particles Y1 of 1.3 g, and white particles W1 of 2 Weigh and mix to 0.0 g, add silicone oil KF-96L-2cs (manufactured by Shin-Etsu Chemical Co., Ltd.) to a liquid volume of 10 g, and ultrasonically stir to give display particle dispersion 2-1 Prepared.
Similarly, display particle dispersions 2-2 to 2-13 were prepared using white particles W2 to W9 instead of the white particles W1, respectively.
評価セルの作製及び評価
　表示用粒子分散液１－２～２－１３を用いた以外は、評価セル１（実施例１）と同様にして、各々評価セルを作製した。
　そして、得えられた各評価セルについて、実施例１と同様に、白表示反射率および応答時間の評価を行ったところ、同じ結果が得られたことが確認できた。 Production and evaluation of evaluation cells Evaluation cells were produced in the same manner as in the evaluation cell 1 (Example 1) except that the display particle dispersions 1-2 to 2-13 were used.
And about each obtained evaluation cell, when the white display reflectance and response time were evaluated similarly to Example 1, it has confirmed that the same result was obtained.
実施例３
　白色粒子Ｗ１において、表３に従って、モノマー種の配合量を変更してシェル樹脂を合成し、このシェル樹脂を用いた以外は、白色粒子Ｗ１と同様にして、各々白色粒子Ｗ１４～Ｗ１７を得て、さらに、各々表示用粒子分散液１４～１７を得た。
　そして、表示用粒子分散液１４～１７を用いた以外は、評価セル１（１）と同様にして、評価セル１４～１７を作製し、実施例１と同様の評価を行った。
　なお、白色粒子Ｗ１４～Ｗ１７及び表示用粒子分散液１４～１７において、酸化チタン含有量、一般式（１）の「６ｋＴ/（πｄ３（ρｐ－ρｓ）ｇ）」値は、白色粒子Ｗ１及び表示用粒子分散液１と同じである。 Example 3
In the white particles W1, according to Table 3, the amount of monomer species was changed to synthesize a shell resin. Except for using this shell resin, white particles W14 to W17 were obtained in the same manner as the white particles W1. Further, display particle dispersions 14 to 17 were obtained.
Evaluation cells 14 to 17 were prepared in the same manner as in the evaluation cell 1 (1) except that the display particle dispersions 14 to 17 were used, and the same evaluation as in Example 1 was performed.
In the white particles W14 to W17 and the display particle dispersions 14 to 17, the titanium oxide content, the value of “6 kT / (πd 3 (ρp−ρs) g)” in the general formula (1), The same as the display particle dispersion 1.
粒子の移動速度の測定
　ガラス基板上に３００μｍの間隔で水平対向する２つの対向電極を形成した速度測定用の空セルを作製し、これに各々表示用粒子分散液１０～１３を封入して、速度測定用セルを作製した。
　そして、速度測定用セルの対向極電極間に０．３Ｖ／μｍの電位差を与えて粒子を移動させ、その様子を高速カメラ付き光学顕微鏡を用いて動画撮影した。対向極電極間を粒子群が移動するのに要する時間を計測し、移動速度を算出した。
　具体的には、測定対象となる粒子を対向電極の一方に移動させた状態で、対向電極間に電位差を与え、対向電極間の中央部で、対向電極の他方に半数以上の粒子が移動するまでに要する時間を計測し、その時間と対向極電極間距離（３００μｍ）とから、粒子の移動速度を算出した。
　なお、測定対象は白色粒子と着色粒子のうち移動速度の遅いシアン粒子とし、それぞれ、シアン粒子の移動速度（Ｖｃ：μｍ／ｓｅｃ）、白色粒子の移動速度（Ｖｗ：μｍ／ｓｅｃ）、及びその比（Ｖｗ／Ｖｃ）を求めた。
　なお、表示用粒子分散液１についても、同様にして、粒子の移動速度を測定した。 Measurement of moving speed of particles An empty cell for measuring speed was prepared by forming two counter electrodes horizontally facing each other at a distance of 300 μm on a glass substrate, and each of them was filled with display particle dispersions 10-13, A cell for speed measurement was produced.
Then, a potential difference of 0.3 V / μm was applied between the counter electrode of the velocity measuring cell to move the particles, and the situation was photographed using an optical microscope with a high-speed camera. The time required for the particle group to move between the counter electrode was measured, and the moving speed was calculated.
Specifically, with the particles to be measured moved to one of the counter electrodes, a potential difference is applied between the counter electrodes, and more than half of the particles move to the other of the counter electrodes at the center between the counter electrodes. The time required for the measurement was measured, and the moving speed of the particles was calculated from the time and the distance between the counter electrodes (300 μm).
The measurement object is cyan particles having a slow moving speed among white particles and colored particles. The moving speed of cyan particles (Vc: μm / sec), the moving speed of white particles (Vw: μm / sec), and The ratio (Vw / Vc) was determined.
For the display particle dispersion 1, the particle moving speed was measured in the same manner.
Figure JPOXMLDOC01-appb-T000005
Figure JPOXMLDOC01-appb-T000005
Figure JPOXMLDOC01-appb-T000006
Figure JPOXMLDOC01-appb-T000006
　表４の結果から、Ｖｗ／Ｖｃが０．２以下となる評価セルがより、表示応答速度に優れていることがわかる。 From the results in Table 4, it can be seen that the evaluation cell having Vw / Vc of 0.2 or less is more excellent in display response speed.
　日本国特許出願２０１２－０４９２６５号の開示はその全体が参照により本明細書に取り込まれる。
　本明細書に記載された全ての文献、特許出願、および技術規格は、個々の文献、特許出願、および技術規格が参照により取り込まれることが具体的かつ個々に記された場合と同程度に、本明細書中に参照により取り込まれる。 The disclosure of Japanese Patent Application No. 2012-049265 is incorporated herein by reference in its entirety.
All documents, patent applications, and technical standards mentioned in this specification are to the same extent as if each individual document, patent application, and technical standard were specifically and individually described to be incorporated by reference, Incorporated herein by reference.

Claims (11)

  1. 　白色顔料及び樹脂を含む表示用白色粒子であって、前記白色顔料の含有量（前記白色顔料の質量/（前記白色顔料及び前記樹脂の総質量））が３０質量％以上９０質量％以下であり、体積平均粒径が１００ｎｍ以上５００ｎｍ以下であり、且つ下記式（１）を満たす表示用白色粒子と、
    　電界に応じて移動する表示用着色粒子であって、白色を除く２種以上の表示用着色粒子と、
    　前記表示用着色粒子及び前記表示用白色粒子を分散する分散媒と、
    　を有する表示用粒子分散液。
    　式（１）　４００≧６ｋＴ/（πｄ３（ρｐ－ρｓ）ｇ）≧３０
    （式（１）中、ｋはボルツマン係数（Ｊ・Ｋ－１）を示す。Ｔは絶対温度２９８（Ｋ）を示す。ｄは前記表示用白色粒子の体積平均粒径（ｎｍ）を示す。ρｐは前記表示用白色粒子の比重（ｇ／ｃｍ３）を示す。ρｓは前記分散媒の比重（ｇ／ｃｍ３）を示す。ｇは重力加速度（ｍ／ｓ２）を示す。）     White particles for display containing a white pigment and a resin, wherein the content of the white pigment (mass of the white pigment / (total mass of the white pigment and the resin)) is 30% by mass or more and 90% by mass or less. White particles for display having a volume average particle size of 100 nm to 500 nm and satisfying the following formula (1):
    Display colored particles that move in response to an electric field, two or more types of display colored particles excluding white,
    A dispersion medium for dispersing the display colored particles and the display white particles;
    A particle dispersion for display.
    Formula (1) 400 ≧ 6 kT / (πd 3 (ρp−ρs) g) ≧ 30
    (In formula (1), k represents the Boltzmann coefficient (J · K −1 ), T represents the absolute temperature 298 (K), and d represents the volume average particle diameter (nm) of the white particles for display. ρp is .ρs showing a specific gravity (g / cm 3) of the display for white particles exhibit specific gravity (g / cm 3) .g showing a gravity acceleration (m / s 2) of the dispersion medium.)
  2. 　前記白色顔料が、酸化チタンである請求項１に記載の表示用粒子分散液。 The display particle dispersion according to claim 1, wherein the white pigment is titanium oxide.
  3. 　前記表示用白色粒子と前記表示用着色粒子との電界に応じて移動する移動速度比（前記表示用白色粒子の移動速度Ｖｗ／前記表示用着色粒子の移動速度Ｖｃ）が、０．２以下である請求項１又は２に記載の表示用粒子分散液。 The moving speed ratio (moving speed Vw of the white particles for display / moving speed Vc of the colored particles for display) that moves according to the electric field between the white particles for display and the colored particles for display is 0.2 or less. The display particle dispersion according to claim 1 or 2.
  4. 　前記分散媒の粘度が、５ｍＰａ・ｓ以下である請求項１～３のいずれか１項に記載の表示用粒子分散液。 The display particle dispersion according to any one of claims 1 to 3, wherein the dispersion medium has a viscosity of 5 mPa · s or less.
  5. 　前記分散媒が、シリコーンオイルである請求項１～４のいずれか１項に記載の表示用粒子分散液。 The display particle dispersion according to any one of claims 1 to 4, wherein the dispersion medium is silicone oil.
  6. 　前記表示用白色粒子の比重が２．１ｇ／ｃｍ３以上４．３ｇ／ｃｍ３以下である請求項１～５のいずれか１項に記載の表示用粒子分散液。 6. The display particle dispersion according to claim 1, wherein the specific gravity of the display white particles is 2.1 g / cm 3 or more and 4.3 g / cm 3 or less.
  7. 　前記分散媒の比重が０．６ｇ／ｃｍ３以上１．２ｇ／ｃｍ３以下である請求項１～６のいずれか１項に記載の表示用粒子分散液。 The display particle dispersion according to claim 1, wherein the specific gravity of the dispersion medium is 0.6 g / cm 3 or more and 1.2 g / cm 3 or less.
  8. 　少なくとも一方が透光性を有する一対の基板と、
    　前記一対の基板間に封入された請求項１～７のいずれか１項に記載の表示用粒子分散液と、
    　前記一対の基板間に、前記表示用着色粒子を移動させる強度の電界を付与する電界発生手段と、
    　を備えた画像表示装置。     A pair of substrates, at least one of which is translucent,
    The display particle dispersion according to any one of claims 1 to 7, which is sealed between the pair of substrates;
    An electric field generating means for applying an electric field having an intensity for moving the display colored particles between the pair of substrates;
    An image display device comprising:
  9. 　請求項８に記載の画像表示装置を備えた電子機器。 An electronic device comprising the image display device according to claim 8.
  10. 　請求項８に記載の画像表示装置を備えた展示用媒体。 An exhibition medium comprising the image display device according to claim 8.
  11. 　請求項８に記載の画像表示装置を備えたカード媒体。 A card medium comprising the image display device according to claim 8.
PCT/JP2013/054578 2012-03-06 2013-02-22 Particle dispersion for display, image display device, electronic appliance, medium for exhibition, and card medium WO2013133047A1 (en)

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