JP2007079532A - Display medium, display element using same, and display method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display medium which makes memory property possible; a display element using the same which has the memory property, high resolution and enable full color display; and a display method. <P>SOLUTION: The display medium has a dimmer function layer that contains mobile fine particles showing coloration in a dispersion state. The display medium has a plurality of dimmer function unit cells containing the dimmer function layer and each dimmer function unit cell is laminated on the surface of substrates or arranged in parallel with the surface of substrates. The plurality of dimmer function unit cells include dimmer function unit cells showing red color, green color and blue color. The mobile fine particles are dispersed in a polymer resin and charged mobile fine particles. In addition, the mobile fine paraticles are metal colloidal particles having plasmon coloring functions. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a display medium using mobile fine particles that can be widely used as an optical element such as a light control glass, a light control element, and a display element, and a display element and display method using the display medium. , Magnetism, etc.) which used a metal colloid with various properties such as reversible color change, adjusting the amount of transmitted and reflected light in a wide wavelength range, presenting various colors, and displaying various patterns. The present invention relates to an optical element.

  With the advancement of an advanced information society, there is an increasing need for electronic paper systems, color display systems, and large area display systems. Display technologies such as CRT, liquid crystal, EL, LED, and plasma have been developed as technologies for realizing these. In addition to these self-luminous systems, the development of a reflective display system with low power consumption and less discomfort to the human eye is being considered. As a reflection type display system, a reflection type liquid crystal technology and the like are prominent.

On the other hand, there is a great need for the next-generation electronic paper display system, but at present, no promising technology has been established. As candidate methods, an electrophoresis method, a liquid crystal method, an organic EL method, and the like are known.
Since the liquid crystal method is a filter method, it is difficult to reduce the thickness and weight of the medium, and the organic EL method is self-luminous and therefore has no memory and limits the range of applications. was there.

On the other hand, the following technologies are disclosed for display elements using the electrophoresis method.
For example, a method of delivering a microcapsule in which a dispersion medium and electrophoretic particles are sealed between a pair of electrodes is disclosed (for example, see Patent Document 1). In addition, a magnetophoresis method using a microcapsule containing a magnetic fluid has been reported (for example, see Patent Document 2).
Furthermore, a method of disposing a plurality of colored particles in a mixed state in a single microcapsule and selectively driving the particles is disclosed (for example, see Patent Document 3).
However, since either method uses a microcapsule, it is difficult to display fine dots or full color. In Patent Document 1, the number of colors that can be displayed simultaneously is two, and multicolor display is difficult. In Patent Document 3, it is theoretically difficult to selectively drive particles.

Further, the charged electrophoretic particles are arranged in almost equal amounts in a plurality of sections divided along the surfaces of the pair of substrates arranged with a predetermined gap therebetween, and the dispersion medium is blue and the charged electrophoretic particles are black. It has been reported that the configuration is described and display quality can be improved (for example, see Patent Document 4).
However, in this configuration, it is difficult to achieve full color, and when trying to stack, color reproduction by subtractive color mixing combined with particles in each layer cannot be performed, so there is a problem that the apparatus must be parallel and complicated. Had.

Further, although a method of performing color display by arranging cells or microcapsules expressing a plurality of colors in parallel is disclosed (for example, refer to Patent Document 5), since it is arranged in parallel, high resolution is disclosed. Is difficult to obtain, and sufficient contrast cannot be obtained.
In addition, a method of laminating two or more electrophoretic parts containing light-transmitting particles / medium in the longitudinal direction is disclosed (for example, see Patent Document 6), but a dye is used to color the particles. Used, and sufficient color density cannot be obtained.

  Furthermore, although a method of providing a plurality of storage units for storing the electrophoresed fine particles is disclosed (for example, refer to Patent Document 7), when performing color display, particles having different colors must be arranged in parallel. Therefore, there is no color reproducibility and high contrast cannot be obtained.

  Furthermore, a method is disclosed in which cells including two display electrodes arranged at overlapping positions, two collect electrodes, and two kinds of translucent colored particles are stacked or arranged in parallel (for example, , See Patent Document 8), since relatively large particles colored with a dye are used, a sufficient color density cannot be obtained, and the stability of the colorant is a problem.

As described above, also in the electrophoresis method, there is a problem of achieving both high resolution and colorization, and this solution has been demanded.
In addition, in the conventional electrophoresis method, particles that have moved to the vicinity of the electrode due to voltage application may diffuse when the voltage is turned off, and the retention property (memory property) may not be sufficient. It was.
JP-A 64-86116 JP-A-4-199085 US Patent No. 6017584 JP 2000-32004 A JP 2000-35598 A Japanese Patent Laid-Open No. 2002-333643 JP 2002-162649 A JP 2004-20818 A

  SUMMARY OF THE INVENTION An object of the present invention is to provide a display medium and a display method using the display medium capable of memory and having the memory, high resolution and full color display.

In view of the above circumstances, the present inventors have conducted intensive research and found that the above problem can be solved by using mobile fine particles that exhibit color developability in a dispersed state, particularly by using plasmon color formation of metal colloid particles. The present invention has been completed.
That is, the present invention is achieved by the following means.

<1> A display medium comprising a light control layer containing mobile fine particles exhibiting color developability in a dispersed state.
<2> The display medium according to <1>, wherein a plurality of light control unit cells including the light control layer are provided, and each of the light control unit cells is stacked on a substrate surface.

<3> The display medium according to <1>, wherein the display medium includes a plurality of dimming unit cells including the dimming layer, and each of the dimming unit cells is arranged in parallel to a substrate surface. .
<4> The above <2> or <3, wherein the plurality of dimming unit cells include a dimming unit cell that exhibits red, a dimming unit cell that exhibits green, and a dimming unit cell that exhibits blue. The display medium according to>.

<5> The display medium according to <1>, wherein the mobile fine particles are dispersed in a polymer resin.
<6> The display medium according to <1>, wherein the mobile microparticle is a charge mobile microparticle.

<7> The display medium according to <1>, wherein the mobile fine particles are dispersed in a medium whose physical and chemical properties are changed by an external stimulus.
<8> The display medium according to <7>, wherein the external stimulus is an electric field.

<9> The display medium according to <7>, wherein the physical and chemical property is viscosity.
<10> The display medium according to <6>, wherein the charge transferable fine particles have a volume average particle diameter of 1 to 100 nm.

<11> The display according to <6>, wherein the particle size distribution of the charge transferable fine particles has one or more maximum peaks, and at least one of the maximum peaks satisfies the following formula (1): Medium.
Formula (1) Pp (± 30) / Pp (T) ≦ 0.5
[In the formula (1), Pp (T) means the maximum peak height of the maximum peak, and Pp (± 30) is the particle diameter of the charge-transferring fine particles at the maximum peak height of ± 30%. It means the peak height in particle diameter. ]

<12> The display medium according to <6>, wherein the charge transferable fine particles are metal colloid particles having a plasmon coloring function.
<13> The display medium according to <12>, wherein the metal colloid particles are gold or silver metal fine particles.

<14> The display medium according to <12>, wherein in the particle size distribution of the metal colloid particles, one peak position (particle diameter) of the maximum peak is 1 to 100 nm.
<15> The display medium according to <14>, wherein in the particle size distribution of the metal colloid particles, one peak position (particle diameter) of the maximum peak is 2 to 70 nm.

<16> A display element comprising a light control layer containing mobile fine particles exhibiting color developability in a dispersed state, and fine particle moving means provided in the vicinity of the light control layer.
<17> The display element according to <16>, wherein the fine particle moving means is a pair of electrodes connected to the light control layer.

<18> The display element according to <17>, wherein a pair of electrodes connected to the light control layer is provided at a part of an outer peripheral end portion of the light control layer.
<19> The display element according to <16>, wherein the display element includes a plurality of light control unit cells including the light control layer, and the plurality of light control unit cells are stacked on a substrate surface.

<20> The display element according to <17>, wherein the display element includes a plurality of dimming unit cells including the dimming layer, and each of the dimming unit cells is arranged in parallel to a substrate surface. .
<21> The above <19> or <20, wherein the plurality of dimming unit cells include a dimming unit cell that exhibits red, a dimming unit cell that exhibits green, and a dimming unit cell that exhibits blue The display element according to>.

<22> The display element according to <16>, wherein the mobile fine particles are dispersed in a polymer resin.
<23> The display element according to <16>, wherein the mobile fine particles are charge mobile fine particles.

<24> The display element according to <16>, wherein the mobile fine particles are dispersed in a medium whose physical and chemical properties are changed by an external stimulus.
<25> The display element according to <24>, wherein the external stimulus is an electric field.

<26> The display element according to <24>, wherein the physical and chemical property is viscosity.
<27> The display element according to <23>, wherein the charge transferable fine particles have a volume average particle diameter of 1 to 100 nm.

<28> The display according to <23>, wherein the particle size distribution of the charge transferable fine particles has one or more maximum peaks, and at least one of the maximum peaks satisfies the following formula (1): element.
Formula (1) Pp (± 30) / Pp (T) ≦ 0.5
[In the formula (1), Pp (T) means the maximum peak height of the maximum peak, and Pp (± 30) is the particle diameter of the charge-transferring fine particles at the maximum peak height of ± 30%. It means the peak height in particle diameter. ]
<29> The display element according to <23>, wherein the charge transferable fine particles are metal colloid particles having a plasmon coloring function.

<30> The display element according to <29>, wherein the metal colloidal particles are gold or silver metal fine particles.
<31> In the particle size distribution of the metal colloidal particles, one peak position (particle diameter) of the maximum peak is 1 to 100 nm. The display element according to the above <29>,

<32> The display element according to <31>, wherein in the particle size distribution of the metal colloid particles, one peak position (particle diameter) of the maximum peak is 2 to 70 nm.
<33> A display method using a display medium having a light control layer containing mobile fine particles exhibiting color developability in a dispersed state, wherein the light control layer develops color according to the dispersed state of mobile fine particles, A display method, wherein the optical layer includes a step of transmitting light in a non-dispersed state of the mobile fine particles, and at least one of these steps is selected for display.

<34> The display method according to <33>, wherein the light control layer is disposed on a substrate, and the light control layer exhibits a color of the substrate due to a non-dispersed state of mobile fine particles.
<35> A display method using a display medium having a light control layer containing mobile fine particles exhibiting color developability in a dispersed state, wherein the light control layer is disposed on a substrate, and the light control layer is mobile fine particles The display method according to <33>, wherein the display is switched by moving in a direction parallel to the substrate surface.

<36> The display method according to <33>, wherein the mobile fine particles are charge-transfer fine particles.
<37> The display method according to <36>, wherein the charge transferable fine particles have a volume average particle diameter of 1 to 100 nm.

<38> The display according to <36>, wherein the particle size distribution of the charge transferable fine particles has one or more maximum peaks, and at least one of the maximum peaks satisfies the following formula (1): Method.
Formula (1) Pp (± 30) / Pp (T) ≦ 0.5
[In the formula (1), Pp (T) means the maximum peak height of the maximum peak, and Pp (± 30) is the particle diameter of the charge-transferring fine particles at the maximum peak height of ± 30%. It means the peak height in particle diameter. ]

<39> The display method according to <36>, wherein the charge transferable fine particles are metal colloid particles having a plasmon coloring function.
<40> The display method according to <39>, wherein the metal colloidal particles are metal fine particles of gold or silver.

<41> The display method according to <39>, wherein in the particle size distribution of the metal colloid particles, one peak position (particle diameter) of the maximum peak is 1 to 100 nm.
<42> The display method according to <41>, wherein in the particle size distribution of the metal colloid particles, one peak position (particle diameter) of the maximum peak is 2 to 70 nm.

  According to the present invention, it is possible to provide a display medium and a display method that have a memory property, a memory property, a high resolution, a full color display, and an excellent display device using the same.

Hereinafter, the present invention will be described in detail.
<Display medium and display method using the same>
The display medium of the present invention is characterized by having a light control layer containing mobile fine particles exhibiting color developability in a dispersed state.
Further, the display method of the present invention is a display method using the display medium of the present invention, wherein the light control layer develops color depending on the dispersion state of the mobile fine particles, and the light control layer is non-movable fine particles. And a step of transmitting light in a dispersed state, and at least one of these steps is selected and displayed.
With the display method having the above-described configuration, color display is possible.
Furthermore, in the display method of the present invention, it is preferable that the light control layer is disposed on a substrate, and the light control layer switches the display by moving the movable fine particles in a direction parallel to the substrate surface.

Next, the display medium of the present invention and the display method using the same will be specifically described.
When the display medium of the present invention and the display method using the display medium are in a state where the mobile fine particles are dispersed in the light control layer, the color of the mobile fine particles exhibiting color developability is displayed. Moreover, when the movable fine particles in the light control layer are in a non-dispersed state, a color in a state of transmitting light can be displayed.
For example, when the display medium of the present invention is in a state where the light control layer is in front of the viewer and the substrate (for example, white) is in the back of the display medium, various color displays are possible.
In the display method of the present invention, the dimming layer is disposed on the substrate, and the dimming layer moves the movable fine particles in a direction parallel to the substrate surface, whereby the color display can be switched. .
Here, the term “move in the direction parallel to the substrate surface” means that the movable fine particles move to the side surface different from the substrate side surface of the light control layer and the surface side facing the substrate with respect to the substrate surface. It will be referred to as a non-dispersed state, or conversely, a movement that becomes a dispersed state by translating the entire light control layer, and all movements that involve movement in the parallel direction.
For example, when an observer observes the light control layer in a state where the back is a substrate, (1) the mobile fine particles move to at least one side of the left and right to be in a non-dispersed state or vice versa. In addition, (2) by moving the movable fine particles from one side of the left and right to the entire light control layer, the color of the substrate in the case of (1) and the dispersed state in the case of (2) It suffices if the color of the particles can be observed, it is only necessary to be accompanied by a parallel movement, and it does not exclude the case where the movement is different from the parallel movement.
Details of the light control layer and the like constituting the display medium of the present invention will be described together when the following display element of the present invention is described.

<Display element>
The display element of the present invention is characterized by having a light control layer containing mobile fine particles exhibiting color developability in a dispersed state, and fine particle moving means provided in the vicinity of the light control layer.
By adopting the above structure, the display element of the present invention can be an excellent element capable of high-resolution and full-color display.

(Light control layer)
The light control layer in this invention is a structure containing the movement microparticles | fine-particles which exhibit color developability in a dispersed state. It is preferable that the mobile fine particles are further charge mobile fine particles. In addition, an insulating liquid, a polymer resin, a high molecular weight pigment dispersant and the like can be added as necessary.

The phrase “exhibiting color developability in a dispersed state” means that the mobile fine particles exhibit a hue that can be visually observed while being dispersed in a medium.
The hue can be varied by changing the metal of the mobile fine particles, particularly the metal colloidal particles, and the shape and particle diameter (volume average particle diameter) thereof.
The color development by the metal colloid such as the gold colloid is caused by electron plasma vibration and is caused by a color development mechanism called plasmon absorption. Color development due to this plasmon absorption is said to be because free electrons in the metal are shaken by the photoelectric field, electric charges appear on the particle surface, and nonlinear polarization occurs.
The coloration by this metal colloid has high saturation and light transmittance, and is excellent in durability.
In addition, plasmon-colored metal colloidal particles have a greater coloring power than conventional pigments, dyes, and the like, and have a high saturation, color purity, sharpness, and light transmittance. It can also be said that the dispersibility therein is good, sedimentation and aggregation are unlikely to occur, and the durability and the like are excellent.
Such color formation by the metal colloid is observed in so-called nanoparticles having a particle size of about several nm to several tens of nm, and the colorant is advantageously a colloid having a narrow particle size distribution.

(Migrating fine particles)
The mobile fine particles in the present invention are not particularly limited as long as they are fine particles that exhibit color developability in a dispersed state and have mobility by applying an external stimulus. Examples of the external stimulus include an electric field and a magnetic field, and among them, an electric field and a magnetic field are preferable from the viewpoints of dispersibility and mobility, and controllability thereof. Examples of such mobile microparticles include charge mobile microparticles that exhibit mobility by applying an electric field (voltage), and magnetic mobile microparticles that exhibit mobility by applying magnetism.
In the present invention, from the viewpoint of dispersibility and mobility, charge transferable fine particles and magnetic transferable fine particles are preferable.

-Charge transfer fine particles-
Any charge transferable fine particles can be used as long as they are used in electrophoresis. Among these, metal colloid particles having the above-described plasmon coloring function are preferable from the viewpoint of colorability and stability.
Hereinafter, metal colloid particles will be described as an example, but the present invention is not limited thereto.
Examples of the metal of the metal colloidal particles include noble metals, copper and the like (hereinafter collectively referred to as “metals”), and the noble metals are not particularly limited. For example, gold, silver, ruthenium, rhodium, palladium, osmium , Iridium, platinum and the like. Among the metals, gold, silver, and platinum are preferable, and gold or silver is more preferable.

The metal colloidal particles can be prepared by a chemical method of reducing metal ions to form nanoparticles through metal atoms and metal clusters, or by using a cold trap to remove the metal that has become fine particles by evaporating bulk metal in an inert gas. A physical method is known in which a metal thin film is formed by trapping or vacuum deposition on a polymer thin film and then heated to break the metal thin film and disperse the metal fine particles in the polymer in a solid state. The chemical method does not require the use of a special apparatus and is advantageous for the preparation of the metal colloidal particles of the present invention. Therefore, general examples will be described later, but the present invention is not limited thereto.
The metal colloidal particles are formed from the metal compound. The metal compound is not particularly limited as long as it contains the metal, for example, chloroauric acid, silver nitrate, silver carboxylate, silver acetate, silver perchlorate, chloroplatinic acid, potassium chloroplatinate, Examples include copper (II) chloride, copper (II) acetate, and copper (II) sulfate.

The metal colloid particles can be obtained as a dispersion of metal colloid particles protected by a dispersant by dissolving the metal compound in a solvent and then reduced to a metal. It can also be obtained in the form of a solid sol. Any form other than these may be used.
When the metal compound is dissolved, a high molecular weight pigment dispersant described later can be used. By using a polymer pigment dispersant, it can be obtained as stable metal colloidal particles protected with the dispersant.

When using the metal colloidal particles in the present invention, it can be used as a dispersion of the metal colloidal particles obtained above, or the solid sol from which the solvent has been removed can be redispersed in a solvent. The invention is not particularly limited.
When used as a dispersion of the metal colloidal particles, the solvent used for the preparation is preferably an insulating liquid described later. When the solid sol is redispersed and used, any solvent can be used as the solvent for preparing the solid sol, and is not particularly limited. The solvent for redispersion is preferably an insulating liquid described later.

The volume average particle diameter of the charge transfer fine particles is preferably 1 to 100 nm, more preferably 2 to 50 nm, and particularly preferably 5 to 50 nm.
The metal colloidal particles can be colored in various colors depending on the type and shape of the metal and the volume average particle diameter. Therefore, by using the charge transferable fine particles whose metal type, shape, and volume average particle diameter are controlled, various hues including RGB coloring can be obtained, and the display element of the present invention is a color display element. be able to. Furthermore, an RGB full-color display element can be obtained by controlling the shape and particle size of the metal and the resulting metal colloidal particles.

  The volume average particle size of the metal colloidal particles for exhibiting R, G, and B colors in the RGB method depends on the metal used, the preparation conditions, the shape, etc. of the particles, and thus cannot be particularly limited. For example, in the case of colloidal gold particles, as the volume average particle size increases, R color development, G color development, and B color development tend to be exhibited.

As a method for measuring the volume average particle diameter in the present invention, a laser diffraction scattering method is employed in which a particle group is irradiated with laser light and the average particle diameter is measured from the intensity distribution pattern of diffraction and scattered light emitted therefrom.
For example, the value measured with the Nikkiso Co., Ltd. micro track particle size distribution measuring device MT3300EX was adopted.

The particle size distribution of the charge transferable fine particles of the present invention preferably has one or more maximum peaks, and at least one of the maximum peaks satisfies the following formula (1).
Formula (1) Pp (± 30) / Pp (T) ≦ 0.5
[However, in formula (1), Pp (T) means the maximum peak height of the maximum peak (the height of the peak of the maximum peak), and Pp (± 30) indicates the metal fine particle at the maximum peak height. It means the peak height at a particle diameter of ± 30%. ]

By satisfying the above formula (1), the plasmon absorption peak becomes sharper and a clearer color display becomes possible, and the particle size distribution becomes narrower, so that the particle charge amount also becomes narrower. There is a tendency that the variation in speed is reduced and the response time at the time of display switching is quickened.
By the above, the contrast of the image displayed using the display element and display method using the display medium of the present invention becomes larger, and the sharpness can be further improved.

  Among the above ranges, Pp (T) / Pp (T) in the formula (1) is more preferably 0.4 or less, and particularly preferably 0.3 or less.

  Furthermore, in the particle size distribution of the metal colloid particles, at least one maximum peak position (particle diameter) of the maximum peak, that is, the particle diameter of the so-called metal colloid particles is 1 to 100 nm, although it depends on the type of metal constituting the metal colloid particles. Is preferably in the range of 2-70 nm, more preferably in the range of 3-70 nm.

  The color development wavelength in plasmon color development depends on the particle size of the metal fine particles. For example, when the metal fine particles are made of Au, the color is colored red when the particle size is around 15 nm and blue when the particle size is 45 nm.

The particle size distribution measurement of the metal colloid particles (metal fine particles) and the measurement of at least one maximum peak position (particle diameter) of the maximum peak of the particle size distribution in the present invention can be performed as follows.
The particle diameter (maximum peak position) and particle size distribution of the metal colloid particles are determined by dropping several drops of the dispersion containing the metal colloid particles on a glass plate, drying, and scanning electron microscope (FE-SEM, manufactured by Hitachi: S-5500), and a method of obtaining an image captured at a magnification of 100,000 times by image analysis using an image analyzer (manufactured by Nireco: Luzex AP).
The number of metal fine particles sampled during the image analysis is 100. As the particle diameter (maximum peak position), the equivalent circle diameter converted from the area was used.

  A suitable combination of the volume average particle size, particle size distribution, and maximum peak position of the metal colloid particles in the present invention is more preferred.

  The content (% by mass) of the charge transfer fine particles with respect to the total mass in the light control layer is not particularly limited as long as the desired hue can be obtained, and the content depends on the thickness of the light control layer. Adjustment is effective as a display element. That is, in order to obtain a desired hue, the content is small when the light control layer is thick, and the content can be increased when the light control layer is thin. Generally, it is 0.01-50 mass%.

  The colloidal metal particles can be prepared, for example, by a general preparation method described in the document “Synthesis / Preparation of Metal Nanoparticles, Control Technology and Application Development” (Technical Information Society Publishing, 2004). Can be prepared. One example will be described below, but the present invention is not limited to this.

-Solid sol-
Hereinafter, an example of a solid sol of metal in the preparation of the metal colloid particles will be described.
In the metal solid sol of the present invention, from the viewpoint of colorability, the metal colloidal particles are preferably contained in an amount of 50 mmol or more per 1 kg of the high molecular weight pigment dispersant described later. When the metal colloidal particles are less than 50 mmol, the colorability is insufficient. More preferably, it is 100 mmol or more.

  In the metal solid sol in the present invention, the metal colloidal particles preferably have a volume average particle diameter of 1 to 100 nm. When it is less than 1 nm, the coloring power is low, and when it exceeds 100 nm, the saturation is low. In addition, the solid sol of metal in the present invention preferably exhibits a narrow particle size distribution. A wide particle size distribution is not preferable because the saturation is lowered.

  The metal solid sol in the present invention has high chroma and contains metal colloidal particles at a high concentration, and therefore has good colorability. In addition, the solid sol of metal in the present invention has good compatibility with a polymer resin (binder) such as a resin, and even when added to such a polymer resin (binder), it is stable and does not aggregate. Have good colorability. Other additives may be added as necessary. Furthermore, the form which melt | dissolved in the appropriate solvent and made it hydrosol or organosol can also be used.

-Method for producing solid sol-
An example of the method for producing the metal solid sol will be described below, but is not limited thereto. That is, after dissolving a metal compound in a solvent and adding a high molecular weight pigment dispersant, the metal compound is reduced to form metal colloidal particles protected with the high molecular weight pigment dispersant, and then the solvent is removed. By doing so, a solid sol is obtained.

  In the production method, the metal compound is used after being dissolved in a solvent. The solvent is not particularly limited as long as it can dissolve the metal compound, and examples thereof include water-soluble organic solvents such as water, acetone, methanol, and ethylene glycol. These may be used alone or in combination of two or more. In the present invention, it is preferable to use water and a water-soluble organic solvent in combination.

  When the solvent is a mixed solvent composed of water and a water-soluble organic solvent, it is preferable to first dissolve the metal compound in water and then add the water-soluble organic solvent to form a solution. At this time, the metal compound is preferably dissolved in water so as to be 50 mM or more. If it is less than 50 mM, a solid sol containing a high proportion of metal colloidal particles cannot be obtained. More preferably, it is 100 mM or more.

  When silver is used as the metal, the aqueous solution preferably has a pH of 7 or less. When the pH exceeds 7, for example, when silver nitrate is used as the silver compound, a by-product such as silver oxide is generated when silver ions are reduced, and the solution becomes cloudy. When the pH of the aqueous solution exceeds 7, it is preferable to adjust the pH to 7 or less by adding, for example, about 0.1 N nitric acid or the like.

  The water-soluble organic solvent is preferably added so that the volume ratio is 1.0 or more with respect to the water in which the metal compound is dissolved. If it is less than 1.0, the water-insoluble high molecular weight pigment dispersant does not dissolve. More preferably, it is 5.0 or more.

  In preparing the metal colloidal particles in the present invention, it is also effective to add a high molecular weight pigment dispersant to the solution of the metal compound. The high molecular weight pigment dispersant is preferably water-insoluble when the solvent is a mixed solvent composed of water and a water-soluble organic solvent. When it is water-soluble, it is difficult to deposit colloidal particles when a water-soluble organic solvent is removed to obtain a solid sol. Examples of the water-insoluble high molecular weight pigment dispersant include Dispersic 161, Dispersic 166 (manufactured by BYK Chemie), Solsperse 24000, Solsperse 28000 (manufactured by Geneca) and the like.

  The amount of the high molecular weight pigment dispersant added is preferably 20 to 1000 parts by weight with respect to 100 parts by weight of the metal. When the amount is less than 20 parts by weight, the dispersibility of the metal colloidal particles is insufficient. When the amount exceeds 1000 parts by weight, the high molecular weight pigment dispersant is mixed into the binder resin when blended in a paint or resin molding. The amount increases, and the physical properties and the like are liable to occur. More preferably, it is 50 to 650 parts by weight.

  In the preparation of the metal colloidal particles in the present invention, the high molecular weight pigment dispersant is added to the solution of the metal compound, and then the metal ions are reduced. The reduction method is not particularly limited, and examples thereof include a method of chemical reduction by adding a compound and a method of reduction by light irradiation using a high-pressure mercury lamp.

  The above compound is not particularly limited. For example, alkali metal borohydride salts such as sodium borohydride conventionally used as a reducing agent; hydrazine compounds; citric acid or a salt thereof, succinic acid or a salt thereof, and the like are used. can do. In the present invention, an amine can be used in addition to the reducing agent.

  The amine is reduced to a metal near room temperature by adding the amine to the metal compound solution and stirring and mixing the amine. By using the above-mentioned amine, it is not necessary to use a reducing agent having high risk and harmfulness, and it is about 5 to 100 ° C., preferably 20 to 80 ° C. without using heating or a special light irradiation device. The metal compound can be reduced at about the reaction temperature.

  The amine is not particularly limited. For example, propylamine, butylamine, hexylamine, diethylamine, dipropylamine, dimethylethylamine, diethylmethylamine, triethylamine, ethylenediamine, N, N, N ′, N′-tetramethylethylenediamine, Aliphatic amines such as 1,3-diaminopropane, N, N, N ′, N′-tetramethyl-1,3-diaminopropane, triethylenetetramine, tetraethylenepentamine; piperidine, N-methylpiperidine, piperazine, Cycloaliphatic amines such as N, N′-dimethylpiperazine, pyrrolidine, N-methylpyrrolidine and morpholine; Aromatic amines such as aniline, N-methylaniline, N, N-dimethylaniline, toluidine, anisidine and phenetidine; , N- methylbenzylamine, N, N- dimethylbenzylamine, phenethylamine, xylylenediamine, N, N, N ', an aralkyl amine such as N'- tetramethyl xylylene diamine. Examples of the amine include methylaminoethanol, dimethylaminoethanol, triethanolamine, ethanolamine, diethanolamine, methyldiethanolamine, propanolamine, 2- (3-aminopropylamino) ethanol, butanolamine, hexanolamine, dimethylamino. Mention may also be made of alkanolamines such as propanol. Of these, alkanolamines are preferred.

  The addition amount of the amine is preferably 1 to 50 mol with respect to 1 mol of the metal compound. When the amount is less than 1 mol, the reduction is not sufficiently performed. When the amount exceeds 50 mol, the stability of the produced colloidal particles against aggregation is lowered. More preferably, it is 2-8 mol.

  Moreover, when using the said sodium borohydride as said reducing agent, since it can reduce | restor at normal temperature, it is not necessary to use a heating or a special light irradiation apparatus.

  The amount of sodium borohydride added is preferably 1 to 50 mol with respect to 1 mol of the metal compound. When the amount is less than 1 mol, the reduction is not sufficiently performed. When the amount exceeds 50 mol, the stability of the produced colloidal particles against aggregation is lowered. More preferably, it is 1.5-10 mol.

  When citric acid or a salt thereof is used as the reducing agent, metal ions and the like can be reduced by heating to reflux in the presence of alcohol. As the citric acid or a salt thereof, sodium citrate is preferably used.

  The addition amount of the citric acid or a salt thereof is preferably 1 to 50 mol with respect to 1 mol of the metal compound. When the amount is less than 1 mol, the reduction is not sufficiently performed. When the amount exceeds 50 mol, the stability of the produced colloidal particles against aggregation is lowered. More preferably, it is 1.5-10 mol.

  In the preparation of the metal colloidal particles in the present invention, after the metal ions are reduced, the metal colloidal particles protected with the high molecular weight pigment dispersant are precipitated, and then the solvent is removed. When water and a water-soluble organic solvent are used as the solvent, the solvent can be removed according to the following method depending on the properties of the high molecular weight pigment dispersant used.

  When the high molecular weight pigment dispersant is water-insoluble, first, the water-soluble organic solvent is removed by evaporation or the like to precipitate metal colloidal particles protected with the high molecular weight pigment dispersant, It is preferred to remove water. Since the high molecular weight pigment dispersant is insoluble in water, the removal of the water-soluble organic solvent precipitates the metal colloidal particles protected by the high molecular weight pigment dispersant.

  In this case, the water-soluble organic solvent preferably has a higher evaporation rate than water. When the evaporation rate is smaller than that of water, when the water-insoluble one is used as the high molecular weight pigment dispersant, the water-soluble organic solvent may be removed first when the solvent is removed to form a solid sol. The colloidal particles of metal cannot be precipitated.

  When the high molecular weight pigment dispersant is of a solvent type, an excessive amount of a nonpolar organic solvent that does not dissolve the high molecular weight pigment dispersant is added to precipitate colloidal particles of metal protected by the high molecular weight pigment dispersant. Then, the solvent can be removed by decantation or the like.

  The metal colloidal particles protected with the high molecular weight pigment dispersant may be washed with ion-exchanged water after removing the solvent and the metal colloidal particles protected with the high molecular weight pigment dispersant. When the metal colloidal particles protected with the high molecular weight pigment dispersant are precipitated by an excessive amount of the nonpolar solvent, the metal colloidal particles can be washed with the nonpolar organic solvent.

  In the method for producing a metal solid sol in the present invention, the obtained metal solid sol has a colloid average particle size of 1 to 100 nm and a narrow particle size distribution, so that it is dark and highly saturated.

  The method for producing a metal solid sol according to the present invention is a process in which the metal compound is dissolved in a solvent to form a solution, the high molecular weight pigment dispersant is added, the metal compound is reduced, and then the solvent is removed. In addition, it is possible to produce a metal solid sol having high saturation and containing metal colloidal particles at a higher concentration than conventional metal solid sols. In particular, by using alkanolamine, it can be easily produced under mild conditions of about 20 to 80 ° C.

Although the metal colloidal particles can be prepared by the above method, commercially available metal colloidal particles can be used as the metal colloidal particles in the present invention as long as the particles exhibit color development in a dispersed state.
Furthermore, although the said metal colloid particle can be specifically prepared by using the following method (1)-(4), it is not limited to this.

-Preparation method of metal colloidal particle dispersion-
As a method for preparing the dispersion of the metal colloid particles in the present invention, it can be prepared in either an aqueous or nonpolar solvent system. For example, a dispersion of metal colloidal particles using gold and silver can be prepared by the following preparation method, but is not limited thereto.

(1) After dissolving a metal compound (for example, tetrachlorogold (III) acid tetrahydrate) in an insulating liquid (for example, water), it is 1.5 times higher in weight than the metal (for example, gold). An aqueous solution containing a molecular weight pigment dispersant (for example, Solsperse 20000) is mixed and stirred.
An aliphatic amine (for example, dimethylaminoethanol) is added to this mixed solution to initiate a reduction reaction of gold ions, followed by filtration and concentration to obtain a colloidal gold particle solution.

(2) After dissolving a metal compound (for example, tetrachloroauric (III) acid tetrahydrate) in water, a high molecular weight pigment dispersant (for example, 1.5 times the weight of the metal (for example, gold)) A solution obtained by dissolving Solsperse 24000 in a nonpolar organic solvent (for example, acetone) is mixed and stirred.
An aliphatic amine (for example, dimethylaminoethanol) is added to this mixed solution to initiate a reduction reaction of gold ions, and then the nonpolar solvent is evaporated to obtain a solid sol composed of colloidal gold particles and a high molecular weight pigment dispersant. . Thereafter, the solid sol is washed with water by decantation, and a nonpolar organic solvent (for example, ethanol) is added to obtain a colloidal gold particle solution.

(3) After dissolving a metal compound (for example, silver nitrate (I)) in water, an aqueous solution containing a high molecular weight pigment dispersant (for example, Solsperse 20000) that is 1.5 times the weight of the metal (for example, silver). Mix and stir. An aliphatic amine (for example, dimethylaminoethanol) is added to the mixed solution to start a silver ion reduction reaction, followed by filtration and concentration to obtain an aqueous silver colloidal particle solution.

(4) After dissolving a metal compound (for example, silver (I) nitrate) in water, a high molecular weight pigment dispersant (for example, Solsperse 24000) having a weight 1.5 times that of the metal (for example, silver) is added to the nonpolar organic solvent. A solution dissolved in (for example, acetone) is mixed and stirred. An aliphatic amine (for example, dimethylaminoethanol) is added to the mixed solution to initiate a silver ion reduction reaction, and then the nonpolar solvent is evaporated to obtain a solid sol composed of silver colloid particles and a high molecular weight pigment dispersant. Thereafter, the solid sol is washed with water by decantation, and a nonpolar organic solvent (for example, toluene) is added to obtain a solvent-based silver colloid particle solution.

  As the metal colloid particles and their solutions, those described in JP-A-11-76800 [0071] to [0103] can be suitably used.

−Insulating liquid−
The dispersion medium for the metal colloid particles in the present invention is preferably an insulating liquid.
Specific examples of the insulating liquid include hexane, cyclohexane, toluene, xylene, decane, hexadecane, kerosene, paraffin, isoparaffin, silicone oil, dichloroethylene, trichloroethylene, perchloroethylene, high-purity petroleum, ethylene glycol, and alcohols. , Ethers, esters, dimethylformamide, dimethylacetamide, dimethylsulfoxide, N-methylpyrrolidone, 2-pyrrolidone, N-methylformamide, acetonitrile, tetrahydrofuran, propylene carbonate, ethylene carbonate, benzine, diisopropylnaphthalene, olive oil, isopropanol, trichloro Trifluoroethane, tetrachloroethane, dibromotetrafluoroethane, etc. and mixtures thereof are preferred. It can be used for.
Moreover, water (so-called pure water) can also be suitably used by removing impurities so that the following volume resistance value is obtained. The volume resistance value is preferably 10 ³ Ωcm or more, more preferably 10 ⁷ Ωcm to 10 ¹⁹ Ωcm, and further preferably 10 ¹⁰ to 10 ¹⁹ Ωcm. By setting such a volume resistance value, the generation of bubbles due to the electrolysis of the liquid due to the electrode reaction is more effectively suppressed, and the electrophoretic characteristics of the particles are not impaired every time energization is achieved. Repeatable stability can be imparted.
The insulating liquid can be added with an acid, alkali, salt, dispersion stabilizer, stabilizer for the purpose of anti-oxidation or UV absorption, antibacterial agent, preservative, etc., if necessary. It is preferable to add so that it may become the range of the specific volume resistance value shown above.

-Polymer resin-
In the present invention, the charge transfer fine particles (metal colloid particles) are also preferably dispersed in a polymer resin. The polymer resin is preferably a polymer gel, a network polymer, or the like.
Examples of the polymer resin include agarose, agaropectin, amylose, sodium alginate, propylene glycol ester of alginate, isolikenan, insulin, ethyl cellulose, ethyl hydroxyethyl cellulose, curdlan, casein, carrageenan, carboxymethyl cellulose, carboxymethyl starch, callose, agar, chitin , Chitosan, silk fibroin, gar gum, quince seed, crown gall polysaccharide, glycogen, glucomannan, keratan sulfate, keratin protein, collagen, cellulose acetate, gellan gum, schizophyllan, gelatin, elephant palm mannan, tunisin, dextran, dermatan sulfate, starch , Tragacanth gum, nigeran, hyaluronic acid, hydroxyethyl cellulose, hydroxy In addition to polymer gels derived from natural polymers such as propyl cellulose, pustulan, funolan, decomposed xyloglucan, pectin, porphyran, methylcellulose, methyl starch, laminaran, lichenan, lentinan, locust bean gum, and synthetic polymers Includes almost all polymer gels.
In addition, polymers containing functional groups of alcohol, ketone, ether, ester, and amide in the repeating unit are exemplified. For example, polyvinyl alcohol, poly (meth) acrylamide and derivatives thereof, polyvinyl pyrrolidone, polyethylene oxide, and the like. Mention may be made of copolymers containing molecules.
Among these, gelatin, polyvinyl alcohol, poly (meth) acrylamide and the like are preferably used from the viewpoints of production stability, electrophoretic characteristics and the like.
These polymer resins are preferably used together with the insulating liquid.

-Media whose physical and chemical properties change due to external stimuli-
The mobile fine particles (particularly metal colloid particles) in the present invention are preferably dispersed in a medium whose physical and chemical properties are changed by an external stimulus from the viewpoint of mobility and memory properties.
As described above, the external stimulus is an electric field, a magnetic field, or the like, and is not particularly limited, but is preferably an electric field and a magnetic field, and more preferably an electric field.
The physical and chemical properties include viscosity, elasticity, hardness, molecular weight, polarization, magnetization, strain, phase transition and the like, and are not particularly limited. From the viewpoint of mobility, viscosity and hardness are preferred, and viscosity is particularly preferred.

  Examples of the medium in which the external stimulus is an electric field and the viscosity changes as a physical and chemical property include colloidal solutions, liquid crystals, or J.P. A. C. S, 2004, 126, p. Examples of the redox-reactive compound described in 12282-12283 include, specifically, silica gel, cellulose, starch, aluminum oxide, ion-exchange resin and the like as particles contained in the colloidal solution, and a redox-reactive compound. Examples thereof include ferrocene compounds such as 11-ferrocenylundecyl) trimethylammonium bromide.

  Examples of the medium in which the external stimulus is a magnetic field and the viscosity changes as a physical and chemical property include a colloidal solution in which fine particles of ferromagnetic material are dispersed.

-High molecular weight pigment dispersant-
Although it does not specifically limit as said high molecular weight pigment dispersant, What is demonstrated below can be used conveniently. Ie;
(1) Comb-like polymer having a pigment affinity group in the main chain and / or a plurality of side chains and having a plurality of side chains constituting a solvation part (2) From a pigment affinity group in the main chain A polymer having a plurality of pigment-affinity moieties (3) a linear polymer having a pigment-affinity moiety comprising a pigment affinity group at one end of the main chain

  Here, the pigment affinity group refers to a functional group having a strong adsorptive power to the pigment surface. For example, in an organosol, a complex having a tertiary amino group, a quaternary ammonium, or a basic nitrogen atom. In the hydrosol, a phenyl group, a lauryl group, a stearyl group, a dodecyl group, an oleyl group, and the like can be given. In the present invention, the pigment affinity group exhibits a strong affinity for metal. The high molecular weight pigment dispersant can exhibit sufficient performance as a protective colloid of metal by having the pigment affinity group.

  The comb-shaped polymer (1) has a structure in which a plurality of side chains constituting a solvation portion are bonded to a main chain together with a plurality of side chains having the pigment affinity group. It is connected to the main chain like a comb tooth. In the present specification, the above structure is referred to as a comb structure. In the comb-shaped polymer (1), the pigment affinity group may be present not only at the end of the side chain but also in the middle of the side chain or in the main chain. In addition, the said solvation part is a part which has affinity to a solvent, Comprising: A hydrophilic or hydrophobic structure is said. The solvation part is composed of, for example, a water-soluble polymer chain, a lipophilic polymer chain, and the like.

  The comb-shaped polymer (1) is not particularly limited, and has, for example, one or more poly (carbonyl-C3-C6-alkyleneoxy) chains disclosed in JP-A-5-177123, Poly (ethyleneimine) having a structure in which each chain has 3 to 80 carbonyl-C3 to C6-alkyleneoxy groups and bonded to poly (ethyleneimine) by an amide or salt bridging group or an acid salt thereof Comprising a reaction product of a poly (lower alkylene) imine disclosed in JP-A-54-37082 and a polyester having a free carboxylic acid group, and each poly (lower alkylene) imine chain A combination of at least two polyester chains; disclosed in JP-B-7-24746 The amount of the epoxy compound, and pigment dispersing agent obtained by reacting a carboxyl group-containing prepolymer of the amine compound having a number average molecular weight from 300 to 7000 concurrently or in any order.

  The comb-shaped polymer (1) is preferably one having 2 to 3000 pigment affinity groups in one molecule. If it is less than 2, the dispersion stability is not sufficient, and if it exceeds 3000, the viscosity is too high and handling becomes difficult, and the particle size distribution of the colloidal particles becomes wide and the saturation is lowered. More preferably, it is 25 to 1500.

  The comb-shaped polymer (1) is preferably one in which 2 to 1000 side chains constituting the solvation portion are present in one molecule. If it is less than 2, the dispersion stability is not sufficient, and if it exceeds 1000, the viscosity is too high and handling becomes difficult, and the particle size distribution of the colloidal particles becomes wide and the saturation is lowered. More preferably, it is 5-500.

  The comb-shaped polymer (1) preferably has a number average molecular weight of 2,000 to 1,000,000. If it is less than 2,000, the dispersion stability is not sufficient, and if it exceeds 1,000,000, the viscosity is too high and handling becomes difficult, and the particle size distribution of the colloidal particles becomes wide and the saturation is lowered. More preferably, it is 4000-500000.

  The copolymer (2) having a plurality of pigment-affinity moieties composed of pigment-affinity groups in the main chain is one in which a plurality of pigment-affinity groups are arranged along the main chain. For example, it is pendant to the main chain. In the present specification, the pigment affinity portion refers to a portion that has one or more pigment affinity groups and functions as an anchor that is adsorbed on the pigment surface.

  Examples of the copolymer (2) include a polyisocyanate disclosed in JP-A-4-210220, a mixture of a monohydroxy compound and a monohydroxymonocarboxylic acid or monoaminomonocarboxylic acid compound, and at least Reaction product of one basic ring nitrogen and a compound having an isocyanate reactive group; disclosed in JP-A-60-16631, JP-A-2-612, and JP-A-63-24410 A polymer in which a plurality of tertiary amino groups or groups having a basic cyclic nitrogen atom are pendant on a main chain made of polyurethane / polyurea; a water-soluble poly (oxyalkylene) disclosed in JP-A-1-279919 A copolymer comprising a steric stabilizing unit having a chain, a structural unit and an amino group-containing unit, and containing an amine group A unit containing a tertiary amino group or a group of an acid addition salt thereof or a quaternary ammonium group, and containing 0.025 to 0.5 milliequivalent amino group per gram of the copolymer. A polymer; a main chain composed of an addition polymer disclosed in JP-A-6-1000064, and a stabilizer unit composed of at least one C1-C4 alkoxy polyethylene or polyethylene-copropylene glycol (meth) acrylate; An amphiphilic copolymer having a weight average molecular weight of 2500 to 20000, the main chain comprising up to 30% by weight of non-functional structural units and a total of up to 70% by weight of stabilizer Units and functional units, the functional units being substituted or unsubstituted styrene-containing units, hydroxyl group-containing units and carboxylic acids. The ratio of hydroxyl group and carboxyl group, hydroxyl group and styrene group, and hydroxyl group and propyleneoxy group or ethyleneoxy group is 1: 0.10 to 26.1; 1: 0. Examples include amphiphilic polymers such as 28 to 25.0; 1: 0.80 to 66.1.

  The copolymer (2) preferably has 2 to 3000 pigment affinity groups in one molecule. If it is less than 2, the dispersion stability is not sufficient, and if it exceeds 3000, the viscosity is too high and handling becomes difficult, and the particle size distribution of the colloidal particles becomes wide and the saturation is lowered. More preferably, it is 25 to 1500.

  The copolymer (2) preferably has a number average molecular weight of 2000 to 1000000. If it is less than 2,000, the dispersion stability is not sufficient, and if it exceeds 1,000,000, the viscosity is too high and handling becomes difficult, and the particle size distribution of the colloidal particles becomes wide and the saturation is lowered. More preferably, it is 4000-500000.

  The linear polymer (3) having a pigment affinity part composed of a pigment affinity group at one end of the main chain has a pigment affinity part composed of one or more pigment affinity groups only at one end of the main chain. However, it has sufficient affinity for the pigment surface.

  The linear polymer (3) is not particularly limited, and for example, an AB block type polymer, one of which is basic disclosed in JP-A-46-7294; US Pat. No. 4,656,226 AB block type polymer in which an aromatic carboxylic acid is introduced into the A block disclosed in the specification of U.S. Pat. No. 4,032,698, one end of which is a basic functional group Block type polymer: AB block type polymer having one end of an acidic functional group disclosed in US Pat. No. 4,070,388; US Pat. No. 4,656,226 disclosed in JP-A-1-204914 What improved the weather yellowing of AB block type polymer which introduce | transduced aromatic carboxylic acid into A block as described in a specification etc. can be mentioned.

  The linear polymer (3) preferably has 2 to 3000 pigment affinity groups in one molecule. If it is less than 2, the dispersion stability is not sufficient, and if it exceeds 3000, the viscosity is too high and handling becomes difficult, and the particle size distribution of the colloidal particles becomes wide and the saturation is lowered. More preferably, it is 5 to 1500.

  The linear polymer (3) preferably has a number average molecular weight of 1,000 to 1,000,000. If it is less than 1000, the dispersion stability is not sufficient, and if it exceeds 1000000, the viscosity is too high and handling becomes difficult, and the particle size distribution of the colloidal particles becomes wide and the saturation is lowered. More preferably, it is 2000-500000.

  As the high molecular weight pigment dispersant, commercially available ones can also be used. Examples of the commercial products include Solsperse 20000, Solsperse 24000, Solsperse 26000, Solsperse 27000, Solsperse 28000 (manufactured by Zeneca); Dispersic 160, Dispersic 161, Dispersic 162, Dispersic 163, Dispersic 166, Dispersic 170, Dispersic 180, Dispersic 182, Dispersic 184, Dispersic 190 (manufactured by BYK Chemie); EFKA-46, EFKA-47, EFKA-48, EFKA-49 (manufactured by EFKA Chemical); polymer 100, polymer 120 , Polymer 150, polymer 400, polymer 401, polymer 402, polymer 403, polymer 450, polymer 451, polymer 45 , Polymer 453 (manufactured by EFKA Chemical Co., Ltd.); Ajisper PB711, Ajisper PA111, Ajisper PB811, Azisper PW911 (manufactured by Ajinomoto Co., Inc.); 700, Floren TG-720W (manufactured by Kyoeisha Chemical Co., Ltd.) and the like.

  The high molecular weight pigment dispersant has a graft structure in which a pigment affinity group is present in a side chain and has a side chain constituting a solvation part [the comb structure polymer (1)]; Since it has a group [the copolymer (2) and the linear polymer (3)], the dispersibility of the colloidal particles is good, and it is suitable as a protective colloid for metal colloidal particles. By using the high molecular weight pigment dispersant, a metal colloidal particle dispersion containing a high concentration of metal colloidal particles can be obtained.

  In the present invention, the high molecular weight pigment dispersant preferably has a softening temperature of 30 ° C. or higher. When the temperature is lower than 30 ° C., the obtained solid sol of metal is blocked during storage. More preferably, it is 40 ° C. or higher.

  The content of the high molecular weight pigment dispersant is preferably 20 to 1000 parts by weight with respect to 100 parts by weight of the metal. When the amount is less than 20 parts by weight, the dispersibility of the metal colloidal particles is insufficient. When the amount exceeds 1000 parts by weight, the high molecular weight pigment dispersant is mixed into the binder resin when blended in a paint or resin molding. The amount increases, and problems such as physical properties tend to occur. More preferably, it is 50 to 650 parts by weight.

-Magnetic mobility particles-
Any magnetically mobile fine particles can be used without limitation as long as they can be used in magnetophoresis. From the viewpoint of color display, it is preferable to use magnetically mobile fine particles obtained by coloring magnetic particles in a desired color. Specific examples of magnetically mobile fine particles colored in a desired color are the magnetic particles described in JP-A-4-175196, page 2, lower right column, line 29 to page 3, lower left column, line 5 (each color). Magnetic particles) can be used.

  The volume average particle diameter of the magnetically mobile fine particles used in the present invention is preferably 1 to 50 μm, and particularly preferably 5 to 20 μm, from the viewpoint of color developability.

  Further, the content (% by mass) of the magnetically mobile fine particles with respect to the total mass in the light control layer is not particularly limited as long as the desired hue can be obtained, and is contained depending on the thickness of the light control layer. It is effective to adjust the amount. That is, in order to obtain a desired hue, the content is small when the light control layer is thick, and the content can be increased when the light control layer is thin. Generally, it is specifically 1 to 50% by mass.

In the case of using charge transferable fine particles in the light control layer in the present invention, it is preferable to have a configuration in which the charge transferable fine particles are movably held in a gap between a pair of opposed transparent substrates. That is, in this case, the fine particle moving means provided in the vicinity of the light control layer is preferably a pair of electrodes connected to the light control layer, and the pair of electrodes is further provided at the outer peripheral end of the light control layer. It is preferable from the viewpoint of manufacturability of the light control layer that the electric field can be efficiently applied.
As a pair of transparent substrates, polyester (for example, polyethylene terephthalate), polyimide, polymethyl methacrylate, polystyrene, polypropylene, polyethylene, polyamide, nylon, polyvinyl chloride, polyvinylidene chloride, polycarbonate, polyether sulfone, silicone resin, Polymer films such as polyacetal resins, fluororesins, cellulose derivatives, and polyolefins, plate substrates, glass substrates, metal substrates, ceramic substrates, and other inorganic substrates are preferably used. The transparent substrate preferably has a light transmittance (visible light) of at least 50%.
Further, the distance between the transparent substrates (the thickness of the light control layer) is appropriately determined depending on the size and weight of the light control element to be manufactured, the color developability, and the like. Generally, it is about 2-1000 micrometers.

  A pair of electrodes is formed on the light control layer in the present invention, and the charge transferable fine particles are electrophoresed by an electric field generated by the electrodes. In particular, at least one of the pair of electrodes is preferably provided at a part of the outer peripheral end of the light control layer. The charge transferable fine particles move toward the electrode provided at a part of the outer peripheral end of the light control layer, whereby the dispersed state of the charge transferable fine particles, that is, the colored state is eliminated.

As such an electrode, a transparent electrode having a light transmittance (visible light) of at least 50% or more is used. Specifically, a metal oxide layer represented by tin oxide-indium oxide (ITO), tin oxide, zinc oxide, or the like is preferably used. Moreover, the electrode may be formed using these materials independently, and may laminate | stack several types of materials.
Various thicknesses and sizes of the electrodes can be used depending on the display element, and are not particularly limited.

In addition, when using the magnetically mobile fine particles in the light control layer in the present invention, it is preferable to have a configuration in which the above-mentioned magnetically mobile fine particles are movably held in a gap between a pair of substrates arranged opposite to each other. A magnetic force generator such as a magnet is preferably used as the fine particle moving means provided in the vicinity of the light control layer.
The magnetic force generator used as the fine particle moving means is appropriately determined depending on the amount of mobile fine particles in the light control layer, the mobility, and the like.

The display element of the present invention is preferably composed of a plurality of dimming unit cells including a dimming layer. Specifically, for example, it is preferable that the plurality of dimming unit cells include a dimming unit cell that exhibits one of red, green, and blue. In order to enable full color display, a plurality of dimming unit cells are preferable. It is preferable that the dimming unit cell includes at least three types: a dimming unit cell that exhibits red (R), a dimming unit cell that exhibits green (G), and a dimming unit cell that exhibits blue (B). It is.
Such a plurality of dimming unit cells may be configured to be stacked on the substrate surface (FIGS. 4 and 7 described later), or may be configured to be arranged in parallel on the substrate surface. Preferred (FIGS. 8 and 9 described later)
The size of the dimming unit cell is closely related to the resolution of the display element, and the smaller the cell, the higher the resolution display element can be manufactured. The size of the light control unit cell is usually about 10 μm to 1 mm, preferably 20 μm to 1 mm, and more preferably 80 μm to 1 mm.

(Display element)
Hereinafter, the display element of the present invention will be described with reference to FIGS. In addition, the same code | symbol is provided to the member which has the same function through all the drawings, and the description is abbreviate | omitted.
Further, the mobile fine particles contained in the light control layer are as described above.

FIG. 1 is a schematic configuration diagram showing an example of a display element of the present invention and a process for manufacturing the same.
The display element shown in FIG. 1C has a first electrode 2 on the entire surface of the first substrate 1, an insulating layer 5 on the upper layer, and a line-shaped second electrode on one side of the first substrate 1. 4 and a partition wall 6, another partition wall 6 is provided opposite to the partition wall 6 on the other side, and a second substrate 8 is provided to face the first substrate 1 to form one cell. It has become the composition.
That is, the first electrode and the second electrode are stacked on one side of the substrate with the horizontal and vertical positions shifted with respect to the substrate surface, and the second electrode overlaps the first electrode in the horizontal direction It has composition which has.
In the cell, a dispersion liquid containing charge transferable fine particles 10 and an insulating liquid 9 is enclosed. The joint surface between the partition wall 6 and the second substrate 8 is bonded by a heat-fusible adhesive layer 7. The front side and the back side in FIG. 1C are partition walls (not shown) with other cells.
FIG. 1D is a schematic configuration diagram of a display element that can apply a voltage by applying voltage applying means to FIG.

The operation of the display element of the present invention will be described below with reference to FIGS. 1 (c) and 1 (d).
When no voltage is applied, the charge transferable fine particles 10 are uniformly dispersed in the cell as shown in FIG. 1C, and the color of the charge transferable fine particles 10 is observed as a cell color (for example, red). The On the other hand, when the voltage is applied, the charge-moving fine particles 10 that are negatively charged move to the positive electrode (second electrode 4) side, so the color of the first substrate (for example, white) through the transparent electrode Appears and the display element is observed as a white display.
Here, the movement of the charge-moving fine particles 10 when a voltage is applied is parallel to the surfaces of the substrates 1 and 8.

  Examples of the substrates 1 and 8 include polyester (for example, polyethylene terephthalate), polyimide, polymethyl methacrylate, polystyrene, polypropylene, polyethylene, polyamide, nylon, polyvinyl chloride, polyvinylidene chloride, polycarbonate, polyether sulfone, and silicone resin. , Polymer films such as polyacetal resins, fluororesins, cellulose derivatives, polyolefins, and inorganic substrates such as plate substrates, glass substrates, metal substrates, ceramic substrates, etc. are preferably used, and at least one of the substrates is light-transmitting It is preferable. When used as a transmissive optical element, a substrate having a light transmittance of at least 50% is preferably used.

As the material of the first and second electrodes 2 and 4, a material in which a metal oxide layer represented by tin oxide-indium oxide (ITO), tin oxide, zinc oxide or the like is formed is preferably used. A transparent electrode having a light transmittance of at least 50% is preferably used. In the case of a reflective optical element application, as an electrode material used for the electrode 2 far from the viewing direction, metal oxides typified by the tin oxide-indium oxide (ITO), tin oxide, zinc oxide and the like are used. In addition to the physical layer, a conductive polymer or a metal layer typified by carbon, copper, aluminum, gold, silver, nickel, platinum, or the like can be used.
As materials for the first and second electrodes, these materials may be used alone or a plurality of types of materials may be laminated.
When both the electrodes 2 and 4 are transparent electrodes, they can also be used as transmissive display elements.
Various thicknesses and sizes of the first electrode and the second electrodes 2 and 4 can be used depending on the display element, and are not particularly limited.
The height of the partition wall 6 is not particularly limited, and is usually about 2 μm to 1 mm, preferably 5 μm to 1 mm, and more preferably 10 μm to 1 mm.
The width of the partition wall 6 is not particularly limited, but generally a smaller width is more effective from the viewpoint of the resolution of the display element, and is usually about 1 μm to 1 mm, preferably 2 μm to 1 mm, more preferably 5 μm to 1 mm.

The material of the adhesive layer 7 is not particularly limited, and a thermosetting resin, an ultraviolet light curable resin, or the like can be used. However, the material for the partition and the material constituting the element such as the insulating liquid can be used. Materials that do not affect are selected.
The material of the insulating layer 5 is not particularly limited, and a known insulating material can be used. For example, an acrylic resin, a polyimide resin, an amorphous fluorine resin, or the like can be used.
The material of the partition 6 is not particularly limited, and a known photosensitive resin can be used.
Further, as shown in FIG. 3 to be described later, when an electrode having a function of a partition is used as the partition, it coincides with the electrode material.

Subsequently, the display element of FIG. 2B will be described.
In the second (b) display element, the first electrode 2 and the second electrode 4 are provided in a line shape on both sides of the first substrate 1, that is, provided in parallel to the substrate surface. A partition wall 6 is provided thereon, and a second substrate 8 facing the first substrate 1 is further provided to form one cell. Furthermore, in FIG. 2 (c), it has the structure which has a voltage application means to both electrodes.
In the cell, a dispersion liquid containing charge transferable fine particles 10 and an insulating liquid 9 is enclosed.

The line width of the electrodes is not particularly limited, but is usually about 2 μm to 1 mm, preferably 5 μm to 1 mm, and more preferably 10 μm to 1 mm.
The thickness of both electrodes is not particularly limited, but is usually about 10 nm to 5 μm, preferably about 10 nm to 1 μm, and more preferably 20 nm to 600 nm.
The height of the partition wall 6 is not particularly limited, but is usually about 2 μm to 1 mm, preferably about 5 μm to 1 mm, and more preferably 10 μm to 1 mm.
Although it does not specifically limit as a width | variety of the said partition 6, Usually, it is 1 micrometer-1 mm, Preferably it is about 2 micrometer-1 mm, More preferably, it is 5 micrometers-1 mm.
The front side and the back side in FIG. 2B are partition walls (not shown) with other cells.
The operation of the display element in FIG. 2B is the same as that in FIG.

In the display element of FIG. 3B, the first electrode 2 and the second electrode 4 are provided in a line shape on both sides of the first substrate 1, and the second substrate 8 is provided opposite to the first substrate 1. Only one cell is formed. In the cell, a dispersion liquid containing charge transferable fine particles 10 and an insulating liquid 9 is enclosed. The joint surfaces of the electrodes 2 and 4 having the function of partition walls and the second substrate 8 are bonded by a heat-bonding adhesive layer 7. The front side and the back side of FIG. 3B are partition walls (not shown) with other cells.
The line width of the electrodes 2 and 4 is not particularly limited, but is usually 2 μm to 1 mm, preferably about 5 μm to 1 mm, and more preferably 10 μm to 1 mm.
Although the height of both the electrodes 2 and 4 is not specifically limited, It is about 2 micrometers-1 mm, Preferably it is about 5 micrometers-1 mm, More preferably, it is 10 micrometers-1 mm.
The operation of the display element in FIG. 3 is the same as that in FIG.

4C has a three-layer structure in which three cells shown in FIG. 2 are stacked vertically. In other words, a plurality of light control unit cells (light control layers) are stacked so that their light control surfaces overlap each other.
The lowermost red (R) dimming unit cell is prepared in the same manner as in FIG. 2, followed by the middle layer green (G) dimming unit cell, and finally the uppermost blue (B) dimming unit cell. By creating the color display element, a color display element having a laminated structure can be created.
As another production method, RGB light control unit cells can be produced separately and combined to form a color display element having a laminated structure.
The materials, sizes, and the like of the substrates 1 and 8, the electrodes 2 and 4, and the partition wall 6 used are the same as those in FIGS.
The multilayer color display element of the present invention operates as shown in FIG. 4D when a voltage of 40 V is applied to the first and third layer electrodes.
First, since the dispersed particles are negatively charged, the movement of the particles to the positive electrode is observed when a DC voltage is applied. Thereby, the particles of the first layer and the third layer move to the positive electrode side, and only the particles of the second layer are in a dispersed state. As a result, when observed from above the element, the color of the second layer particles (green) ) Is observed.
Similar operations, for example, when a voltage is applied to the first layer and the second layer, the color (blue) of the particles of the third layer is observed, and when a voltage is applied to the second layer and the third layer, the first The color (red) of the particles in the layer is observed, and a full color display is observed by controlling the voltage application of these three layers.

FIG. 5 is a schematic configuration diagram showing an example of the display element of the present invention and its operation state.
The structure of the display element structure shown in FIGS. 5A and 5B and the structure of the display element structure shown in FIGS. 1C and 1D are the same and can be manufactured in the same manner.
FIG. 6 is a schematic configuration diagram showing an example of the display element of the present invention and its operation state.
The structure of the display element structure shown in FIGS. 6A and 6B and the structure of the display element structure shown in FIGS. 2B and 2C are the same and can be manufactured in the same manner. .
FIG. 7 is a schematic configuration diagram showing an operation state of an example of the display element of the present invention.
The structure of the display element structure shown in FIG. 7 and the structure of the display element structure shown in FIG. 4D are the same and can be manufactured in the same manner.

An example of the display element of the present invention will be described with reference to FIG.
FIG. 8 is a schematic configuration diagram showing an example of the display element of the present invention.
The display element shown in FIG. 8 has a partition wall 6 having partition walls formed on a rear substrate 1 on which a whitened thin film 1a is formed, and further has ITO electrodes 2 and 4 on the side surfaces of the partition wall 6, 6 is filled with the mixed solution of red, green, and blue, and a heat-fusible adhesive layer formed on the bonding surface between the partition wall 6 and the second substrate 8 is used as the second substrate. The display device is configured by adhering 8 to 8 and dimming unit cells of three colors RGB in parallel.

The operation of the display element thus manufactured will be described below.
When a voltage is applied to the electrodes 2.4 of the red light control unit cell R and the blue light control unit cell B, the dispersed R particles 10 and B particles 12 move to the positive electrode side of the respective light control unit cells. In this state, only the G particles 11 in the green dimming unit cell G are dispersed. As a result, when the element is observed from above the display element, the color of the green dimming unit cell G is observed as a green element. Is done.
After that, even when the voltage application is stopped, the movement of the particles is not observed, and is kept in the positive electrode (memory property), and the element continues to display green.

FIG. 9 is a schematic configuration diagram showing an example of the display element of the present invention and its operating state.
The structure of the structure of the display element shown in FIG. 9B and the structure of the structure of the display element shown in FIG. 8 are the same and can be manufactured in the same manner. FIG. 9B shows a form of a display device produced by changing the colloidal gold solution used in FIG. 8 as shown in Example 10 described later.

FIG. 10 is a schematic configuration diagram showing an example of the display element of the present invention and its operation state. Here, a case where magnetic force is used as an external stimulus and magnetic particles are used as mobile fine particles will be described below.
In the display element shown in FIG. 10B, a partition wall 6 is formed on a substrate 1 on which a whitened thin film 1a is formed, and then heat fusion is performed on a bonding surface between the partition wall 6 and the second substrate 8. After the adhesive adhesive layer is provided, the concave portion surrounded by the partition walls 6 is filled with a mixed liquid in which magnetic particles are dispersed, and then the second substrate 8 is heated and pasted. Further, a magnetic field generating means (for example, a magnet) capable of turning on and off the magnetic field generation is provided on one side of the partition wall 6.

The operation of the display element will be described below with reference to FIGS. 10 (a) and 10 (b).
First, when no magnetic force is applied, as shown in FIG. 10A, the display element is formed, and when the display element is observed from above the element, the color exhibited by the magnetic particles is observed. . On the other hand, when a magnetic force is applied, as shown in FIG. 10B, the magnetic particles in the dimming unit cell are affected by the magnetic field and move to the magnet side of the element. The color of the substrate, ie white, is observed.
By replacing the color exhibited by the magnetic particles with another color, a variety of display elements can be obtained. In addition, as the RGB three-color dimming unit cells, a color display element can be obtained by adopting a parallel configuration as shown in FIG.
The manufacturing method of the display element using these magnetic forces can be manufactured by the same method as the above method in the case of using a voltage as an external stimulus.
Further, the magnetic particles and the like are the same as those described in the section of the magnetic mobile fine particles.

  In the display element of the present invention, a driving switching element such as a wiring, a thin film transistor, a diode having a metal / insulating layer / metal structure, a variable capacitor, or a ferroelectric may be formed on the substrate according to the application. .

  Hereinafter, the present invention will be described more specifically with reference to examples. However, these examples do not limit the present invention.

Example 1
An example of the display element of the present invention will be described with reference to FIG.
First, an ITO film having a thickness of 50 nm was formed as a first electrode 2 on a first substrate 1 made of polyethylene terephthalate (PET) having a thickness of 200 μm by a sputtering method and patterned into a line shape (line width: 300 μm). . Next, an acrylic resin layer (thickness: 0.1 μm) was formed as the insulating layer 5 (see FIG. 1A).
Next, aluminum was deposited as the second electrode 4 to a thickness of 50 nm by a vacuum deposition method, and patterned in a line shape by a photolithography method and a dry etching method. The line width was about 30 μm (see FIG. 1B).

Subsequently, after a layer for partition walls was applied using a photosensitive polyimide varnish, exposure and wet etching were performed to form partition walls 6 having a height of 50 μm and a width of 20 μm.
After the heat-bonding adhesive layer 7 is formed on the bonding surface between the partition wall 6 and the second substrate 8, the colloidal gold particles 10 (Finesphere Gold, manufactured by Nippon Paint Co., Ltd., volume average particle diameter) are formed in the partition wall 6. After filling with water 9 containing 20 nm), heat was applied to the second substrate 8 made of PET, and a display element was manufactured (see FIG. 1C). In this case, since the particles (metal colloidal particles) 10 show red in a dispersed state, the display element is observed as red when viewed from above the display element.

  Using the display element thus produced, a voltage of 80 V was applied to both electrodes so that the second electrode was positive. Since the dispersed particles were negatively charged, the movement of the particles to the positive electrode was observed when a voltage was applied. Thus, when the first electrode is on the negative side and the second electrode is on the positive side, the particles move to the second electrode side, the white first substrate appears through the transparent first electrode, and the display element is Observed as a white display. By applying an alternating voltage to the electrode of the element displaying white, the particles returned to their original dispersed state and displayed red.

(Example 2)
An example of the display element of the present invention will be described with reference to FIG.
First, an ITO film having a thickness of 50 nm is formed on a first substrate 1 made of polyethylene terephthalate (PET) having a thickness of 200 μm by sputtering, patterned into a line shape, and a first electrode 2 and a second electrode 4. Formed. The line width was about 30 μm (see FIG. 2A).
Subsequently, a layer for partition walls was applied using a photosensitive polyimide varnish, and then exposure and wet etching were performed to form partition walls 6 having a height of 50 μm and a width of 20 μm.
After the heat-bonding adhesive layer 7 is formed on the bonding surface between the partition wall 6 and the second substrate 8, the colloidal gold particles 10 (Finesphere Gold, manufactured by Nippon Paint Co., Ltd., volume average particle diameter) are formed in the partition wall 6. After filling with water 9 containing 20 nm), the second substrate 8 made of PET was applied with heat to produce a display element (see FIGS. 2B and 2C).

  In this case, since the particles (metal colloidal particles) 10 show red in a dispersed state, the display element is observed as red when viewed from above the display element. Using the display element thus fabricated, a voltage of 40 V was applied to both electrodes so that the first electrode was positive. Since the dispersed particles were negatively charged, the movement of the particles to the positive electrode was observed when a voltage was applied. As a result, when the first electrode is set to the plus side and the second electrode is set to the minus side, the particles move to the first electrode side, and the white first substrate appears through the transparent insulating solvent. Was observed as a white display. By applying an alternating voltage to the electrode of the element displaying white, the particles returned to their original dispersed state and displayed red.

(Example 3)
An example of the display element of the present invention will be described with reference to FIG.
A first electrode 2 and a second electrode 4 having a function of a partition wall are formed by depositing gold on a first substrate 1 made of a glass substrate having a thickness of 700 μm to a thickness of 50 μm by plating and then patterning in a line shape. Formed. The line width was about 10 μm (see FIG. 3A).
Next, after the heat-bonding adhesive layer 7 is formed on the bonding surface of the partition walls (both electrodes 2 and 4) with the second substrate, the partition wall is filled with an aqueous dispersion containing gold colloid particles 10. A display element was manufactured by applying heat to the second substrate 8 made of PET (see FIG. 1B). In this case, since the particles show red in a dispersed state, the display element is observed as red.

  Using the display element thus fabricated, a voltage of 40 V was applied to both electrodes 2 and 4 so that the first electrode was positive. Since the dispersed particles were negatively charged, the movement of the particles to the positive electrode was observed when a voltage was applied. As a result, when the first electrode is set to the plus side and the second electrode is set to the minus side, the particles move to the first electrode side, and the white first substrate appears through the transparent insulating solvent. Was observed as a white display. By applying an alternating voltage to the electrode of the element displaying white, the particles returned to their original dispersed state and displayed red.

Example 4
In Example 3, a display element was produced in the same manner as in Example 3 except that gelatin was used instead of the water. The gelatin was dissolved in water, and then colloidal gold particles were added and stirred to prepare gelatin containing colloidal gold particles, which was applied to the cells surrounded by the partition walls by an ink jet method.
Similar to Example 3, the movement of particles was observed by applying a voltage. In addition, by applying an alternating voltage to the electrode of the element displaying white, the particles returned to the original dispersed state and displayed red.

(Example 5)
An example of the display element of the present invention will be described with reference to FIG.
First, an ITO film having a thickness of 50 nm is formed on a first substrate 1 made of polyethylene terephthalate (PET) having a thickness of 200 μm by sputtering, patterned into a line shape, and a first electrode 2 and a second electrode 4. Formed. The line width was about 30 μm (see FIG. 4A).
Subsequently, after a layer for partition walls was applied using a photosensitive polyimide varnish, exposure and wet etching were performed to form partition walls 6 having a height of 50 μm and a width of 20 μm.
After the heat-bonding adhesive layer 7 is formed on the bonding surface between the partition wall 6 and the second substrate 8, gold colloidal particles (red) 10 (fine sphere gold, Nippon Paint ( After filling with water 9 containing a volume average particle size of 20 nm), gold colloidal particles (red) were dispersed by applying heat to the second substrate 8 made of PET on which ITO was formed. A red light control unit cell was produced (see FIG. 4B).

Subsequently, green and blue dimming unit cells were produced on the second substrate 8 as follows.
Instead of using the gold colloid particles (red) in the “process from the formation of the partition walls 6 to the bonding of the second substrate” in the production of the red light control unit cell, the gold colloid particles (green) prepared by the following method are used. A green dimming unit cell was produced on the second substrate 8 of the red dimming unit cell by performing the same operation except that. The green gold colloid aqueous solution was prepared by adding 4 ml of 1% by weight citric acid (manufactured by Tokyo Chemical Industry) to a mixed solution of 1 ml of 1% by weight chloroauric acid (manufactured by Wako Pure Chemical Industries) and 79 ml of pure water, and heated to 60 ° C. Thereafter, 0.01 ml of 0.01% by mass tannic acid was added to obtain a volume average particle size of 30 nm.

Further, in the “process from the formation of the partition wall 6 to the bonding of the second substrate” in the production of the red light control unit cell, the second substrate on which ITO is not formed is used instead of using the second substrate having ITO formed thereon. The same procedure as in the above red dimming unit cell was performed except that the substrate 8 was used and gold colloid particles (blue) prepared by the following method were used instead of gold colloid particles (red). Thus, a blue dimming unit cell was produced. The blue gold colloid aqueous solution was prepared by adding 4 ml of 1% by weight citric acid (manufactured by Tokyo Kasei) to a mixed solution of 1 ml of 1% by weight chloroauric acid (manufactured by Wako Pure Chemical Industries) and 79 ml of pure water, and heated to 60 ° C. Then, 0.0002 mass% tannic acid 0.01ml was added, and the volume average particle diameter of 50 nm was obtained.
Thus, a display element having a laminated structure in which each layer (light control unit cell) is composed of three colors of RGB was obtained.

  A voltage of 40 V was applied to the first and third layer electrodes using the display element thus fabricated. Since the dispersed particles were negatively charged, the movement of the particles to the positive electrode was observed when a voltage was applied. Thereby, the particles of the first layer and the third layer move to the positive electrode side, and only the particles of the second layer are in a dispersed state. As a result, when observed from above the element, the color of the second layer particles (green) ) Was observed.

(Example 6)
An example of the display element of the present invention will be described with reference to FIG.
An ITO film having a thickness of 100 nm was formed as a first electrode 2 on a PET substrate 1 having a thickness of 0.2 mm by sputtering, and was patterned in a line shape by photolithography and dry etching (line width 500 μm). ). Next, an acrylic resin layer (thickness: 0.1 μm) was formed as the insulating layer 5.
Next, aluminum was deposited as a second electrode 4 to a thickness of 50 nm by vacuum deposition, and patterned in a line shape by photolithography and dry etching (line width 50 μm).

Subsequently, after a layer for partition walls was applied using a photosensitive polyimide varnish, the partition walls 6 having a height of 50 μm and a width of 20 μm were formed by performing exposure and wet etching.
A heat-fusible adhesive layer was formed on the joint surface between the partition wall 6 and the second substrate 8.

On the other hand, 1,1-Ferrocenylmethyldecylammonium bromide aqueous solution 100 mM, sodium salicylate aqueous solution 20 mM, NaBr 0.2M were mixed, and an aqueous solution of gold particles (Finesphere Gold, Nippon Paint Co., Ltd., volume average particle diameter 15 nm) was added. Stir.
This mixed liquid was filled in the concave portion surrounded by the partition wall 6 formed in advance, and heat was applied to the second substrate 8 made of PET having a thickness of 0.2 mm to produce a display element.
In this case, since the particles show red in a dispersed state, the display element was observed as red when viewed from above the display element.

  Using the display element thus manufactured, a voltage of 80 V was applied so that the second electrode 4 was positive. Since the dispersed particles were negatively charged, the movement of the particles to the positive electrode was observed when a voltage was applied. Thus, when the first electrode 2 is set to the negative side and the second electrode 4 is set to the positive side, the particles move to the second electrode side, and the white first substrate 1 appears through the transparent first electrode. The display element was observed as a white display. Thereafter, even when the voltage application was stopped, the movement of the particles was not observed, and the particles were held on the second electrode side.

(Example 7)
An example of the display element of the present invention will be described with reference to FIG.
An ITO film having a thickness of 80 nm is formed on a PET substrate 1 having a thickness of 0.2 mm by sputtering, and is patterned into a line shape by photolithography and dry etching. The first electrode 2 and the second electrode 4 was formed (line width 40 μm).

Subsequently, after a layer for partition walls was applied using a photosensitive polyimide varnish, the partition walls 6 having a height of 50 μm and a width of 20 μm were formed by performing exposure and wet etching.
After forming a heat-fusible adhesive layer on the bonding surface between the partition wall 6 and the second substrate 8, the partition wall 6 was filled with the mixed liquid containing the gold particles produced in Example 6, and then the thickness was reduced to 0. A display element was manufactured by applying heat to the second substrate 8 made of 2 mm PET and applying the heat to the second substrate 8.
In this case, since the particles show red in a dispersed state, the display element was observed as red when viewed from above the display element.

  Using the display element thus fabricated, a voltage of 40 V was applied so that the first electrode 2 was positive. Since the dispersed particles were negatively charged, the movement of the particles toward the positive electrode side was observed when a voltage was applied. Thus, when the second electrode 4 is set to the minus side and the first electrode 2 is set to the plus side, the particles move to the first electrode side, the white first substrate 1 appears, and the display element is observed as a white display. It was. Thereafter, even when the voltage application was stopped, the movement of the particles was not observed, and the particles were held on the first electrode side.

(Example 8)
An example of the display element of the present invention will be described with reference to FIG.
An ITO film having a thickness of 50 nm is formed on a PET substrate 1 having a thickness of 0.2 mm by sputtering, and is patterned into a line shape by photolithography and dry etching. The first electrode 2 and the second electrode 4 was formed (line width 30 μm).

Subsequently, after a layer for partition walls was applied using a photosensitive polyimide varnish, the partition walls 6 having a height of 50 μm and a width of 20 μm were formed by performing exposure and wet etching.
After a heat-fusible adhesive layer is formed on the bonding surface between the partition wall 6 and the second substrate 8, the cell surrounded by the partition wall 6 is filled with the mixed solution containing the gold particles prepared in Example 6. Then, heat was applied to the second substrate 8 made of PET on which the ITO film was formed, and bonded together to produce a red light control unit cell in which the gold particles 10 (red) were dispersed.

Subsequently, green and blue dimming unit cells were produced on the second substrate 8 as follows.
Instead of using the mixed solution prepared in Example 6 in the “process from the formation of the partition wall 6 to the bonding of the second substrate 8” in the preparation of the red light control unit cell, the green mixed solution prepared as follows is used. A green dimming unit cell was produced on the second substrate 8 of the red dimming unit cell by performing the same operation except that was used.
The green mixed solution was subjected to the same operation except that gold particles having a volume average particle size of 35 nm were used instead of the gold particles having a volume average particle size of 15 nm used in the step of preparing the red mixed solution in Example 6, A green mixture was prepared.

Further, in the “process from the formation of the partition wall 6 to the bonding of the second substrate 8” in the production of the red light control unit cell, ITO is not deposited instead of using the second substrate having the deposited ITO. The blue dimming unit cell was prepared in the same manner as the red dimming unit cell except that the blue mixed liquid prepared as follows was used instead of using the two substrates. Was made.
The blue mixed solution was subjected to the same operation except that gold particles having a volume average particle size of 55 nm were used in place of the gold particles having a volume average particle size of 15 nm used in the preparation step of the red mixed solution in Example 6. A mixed solution was prepared.

A voltage of 40 V was applied to the pair of electrodes of the first layer R and the third layer B using the display element thus manufactured. The dispersed particles move to the positive electrode, and only the particles of the second layer G are dispersed. As a result, when the element is observed from above the display element, the color of the particles of the second layer, that is, green It was observed as an element.
Thereafter, even when the voltage application was stopped, the movement of the particles was not observed, and the particles were held on the plus side electrode, and the element continued to display green.

Example 9
An example of the display element of the present invention will be described with reference to FIG.
Photosensitive on a back substrate formed by forming a white polyethylene terephthalate (PET) thin film 1a whitened by mixing titanium oxide fine particles on a glass substrate 1 having a thickness of 0.7 mm (# 1737 manufactured by Corning). After applying a layer for the partition 6 using a polyimide varnish, the partition 6 having a height of 50 μm and a width of 20 μm and a partition interval of 1 mm was formed by exposure and wet etching.
Thereafter, ITO electrodes 2 and 4 were formed by a photolithography process and a sputtering process so that ITO was formed on the side surfaces of the partition walls 6.
Thereafter, a heat-bonding adhesive layer is formed on the bonding surface between the partition wall 6 and the second substrate 8, and then red and green produced in the same manner as in Examples 6 and 8 in the recess surrounded by the partition wall 6. Then, after filling the blue mixed solution as shown in FIG. 8, the second substrate 8 was heated and pasted to produce a light control layer in which three colors of RGB were arranged in parallel.

A voltage of 40 V was applied to the electrodes of the red dimming unit cell R and the blue dimming unit cell B using the display element thus fabricated. The dispersed R particles 10 and B particles 12 move to the positive electrode side of each dimming unit cell, and only the G particles 11 in the green dimming unit cell G are dispersed. As a result, display is performed. When the element was observed from above the element, the color of the particles of the green light control unit cell G, that is, a green element was observed.
Thereafter, even when the voltage application was stopped, the movement of the particles was not observed, and the particles were held on the plus side electrode, and the element continued to display green.

(Example 10)
An example of the display element of the present invention will be described with reference to FIG.
After applying a layer for the partition wall 6 to a glass substrate 1 having a thickness of 0.7 mm (Corning Corporation # 1737) using a photosensitive polyimide varnish, the height and width are 20 μm and 20 μm by exposure and wet etching, A partition wall 6 having a partition wall spacing of 1 mm was formed.
Thereafter, ITO electrodes 2 and 4 were formed by a photolithography process and a sputtering process so that an ITO film was formed on the side surface of the partition wall 6 (see FIG. 9A).
Thereafter, a heat-fusible adhesive layer is formed on the bonding surface between the partition wall 6 and the second substrate 8, and then three types of gold colloids that respectively color red, green, and blue in the recesses surrounded by the partition wall 6. After filling with an aqueous solution (volume average particle diameters of 20 nm, 30 nm, and 50 nm, respectively), heat was applied to the second substrate 8 to form a light control layer in which three colors of RGB were arranged in parallel.

The three types of aqueous colloidal gold solutions that develop red, green, and blue, respectively, were prepared as follows.
The red gold colloid aqueous solution was prepared by adding 4 ml of 1% by weight citric acid (manufactured by Tokyo Kasei) to a mixed solution of 1 ml of 1% by weight chloroauric acid (manufactured by Wako Pure Chemical Industries) and 79 ml of pure water, and heated to 60 ° C. Thereafter, it was obtained by adding 0.01 ml of 1% by mass tannic acid.
In addition, in the green and blue gold colloid aqueous solutions, 0.01 mass% tannic acid or 0.0001 mass% tannic acid was used in place of the 1 mass% tannic acid used in the preparation of the red gold colloid aqueous solution. Except for the above, the same operations as in the preparation of the red gold colloid aqueous solution were performed to obtain respective green and blue gold colloid aqueous solutions.

A voltage of 40 V was applied to the electrodes of the red dimming unit cell R and the blue dimming unit cell B using the display element thus fabricated. The dispersed R particles 10 and B particles 12 move to the positive electrode side of each dimming unit cell, and only the G particles 11 in the green dimming unit cell G are dispersed. As a result, display is performed. When the element was observed from above the element, it was observed as the color of the particles of the cell G, that is, as a green element.
Thereafter, by applying an AC voltage to the electrodes of the cell R and the cell B, the R particles and the B particles returned to the original dispersed state.
The time from the green element in which the color of the particle of the cell G was observed until the mixed color of the color of the particle of the cell R, the cell G, and the cell B was observed, the optical density of the transmittance, USB2000 manufactured by Ocean Optics It was 5.2 seconds when the density change time was calculated.

(Example 11)
An example of the display element of the present invention will be described with reference to FIG.
Pentacarbonyl iron (USP 4,803,143) was spray-dried at 250 ° C. to prepare iron powder having a particle diameter of 4 μm (saturated magnetization 150 Am ² / Kg). Next, titanium oxide was added to a solution of 0.3 g of an antioxidant (product name: L-ascorbic acid, manufactured by Wako Pure Chemical Industries, Ltd.) and ethylene-vinyl acetate copolymer resin (30 g) in 500 g of THF. (Product name: Taibake CR-50, manufactured by Ishihara Sangyo Co., Ltd.) 12 g, 18 g of copper phthalocyanine and 90 g of the above iron powder are dispersed, and this dispersion is spray-dried at 50 ° C. to obtain blue magnetic particles having a particle diameter of 10 μm (saturated) Magnetization 60 Am ² / Kg) was obtained.

A layer for partition walls 6 using a photosensitive polyimide varnish on a glass substrate (first substrate 1) having a thickness of 1 mm on which a polyethylene terephthalate (PET) thin film 1a whitened by mixing fine titanium oxide particles is formed. Then, exposure and wet etching were performed to form partition walls 6 having a height of 300 μm and a thickness of 200 μm, with an interval of 1 mm.
Thereafter, a heat-fusible adhesive layer is provided on the bonding surface between the partition wall 6 and the second substrate 8, and the recess surrounded by the partition wall 6 is filled with an isoparaffin mixed liquid in which the blue magnetic particles are dispersed. The second substrate 8 made of this was heated to form a laminated display element.

The display element thus fabricated was observed as blue when observed from above the display element.
After that, by bringing an external magnet (magnetic flux density of 0.3 T) closer to one side of the partition wall 6 of the display element, the blue magnetic particles are affected by the magnetic field and move to the magnet side of the element. The color of the substrate, ie white, was observed.

(Example 12)
Another example of the display element of the present invention will be described with reference to FIG.
After applying a layer for the partition wall 6 to a glass substrate 1 having a thickness of 0.7 mm (Corning Corporation # 1737) using a photosensitive polyimide varnish, the height and width are 20 μm and 20 μm by exposure and wet etching, A partition wall 6 having a partition wall spacing of 1 mm was formed. Thereafter, ITO electrodes 2 and 4 were formed by a photolithography process and a sputtering process so that an ITO film was formed on the side surface of the partition wall 6 (see FIG. 9A).
Then, after forming a heat-fusible adhesive layer (not shown) on the bonding surface between the partition wall 6 and the second substrate 8, red, green, Three types of gold colloidal particle aqueous solutions that color each blue color (volume average particle diameter and maximum peak position coincide at 20 nm, 30 nm, and 50 nm, respectively, and the particle size distribution is Pp (± 30) / Pp ( T) = 0.4 is satisfied, and the second substrate 8 is heated and pasted to produce a light control layer in which three colors of RGB are arranged in parallel (see FIG. 9B). ).

The three aqueous gold colloid particle aqueous solutions that develop red, green, and blue colors, respectively, were prepared as follows. The red gold colloid aqueous solution was prepared by adding 4 ml of 1% by weight citric acid (manufactured by Tokyo Chemical Industry) to a mixed solution of 1 ml of 1% by weight chloroauric acid (manufactured by Wako Pure Chemical Industries) and 69 ml of pure water, and heated to 60 ° C. Thereafter, it was obtained by adding 0.05 ml of 1% by mass tannic acid.
In addition, as the green and blue gold colloid aqueous solutions, 0.01 mass% tannic acid or 0.0001 mass% tannic acid was used in place of the 1 mass% tannic acid used in the preparation of the red gold colloid aqueous solution. Except for the above, the same operations as in the preparation of the red gold colloid aqueous solution were performed to obtain respective green and blue gold colloid aqueous solutions.

The volume average particle size was measured with a Nikkiso Microtrac particle size distribution analyzer MT3300EX.
The particle size distribution measurement and the maximum peak position (particle diameter) were measured by dropping a dispersion containing metal colloidal particles on a glass plate, drying, and then scanning electron microscope (FE-SEM, Hitachi: S -5500), an image captured at a magnification of 100,000 times was obtained by image analysis using an image analyzer (manufactured by Nireco: Luzex AP).
The number of metal fine particles sampled during image analysis was 100, and the particle diameter (maximum peak position) was an equivalent circle diameter converted from the area.

A voltage of 40 V was applied to the electrodes of the cell R and the cell B using the display element thus manufactured. The dispersed R particles 4 and B particles 6 move to the positive electrode side of each cell, and only the G particles 7 in the cell G are dispersed. As a result, when the element is observed from above the display element, The color of the particles in the cell G, ie, a green element was observed. Thereafter, by applying an AC voltage to the electrodes of the cell R and the cell B, the R particles and the B particles returned to the original dispersed state.
The time from the green element in which the color of the particle of the cell G was observed until the mixed color of the color of the particle of the cell R, the cell G, and the cell B was observed, the optical density of the transmittance, USB2000 manufactured by Ocean Optics The concentration change time was calculated to be 4.9 seconds.

It is a schematic diagram which shows an example of the structure which is one aspect | mode of the display element of this invention, and the process which manufactures it with the display element manufactured in Example 1. FIG. (A) is an electrode, a substrate on which an insulating layer is formed, (b) is a substrate in which an electrode is further formed on (a), (c) is a display element, (d) is provided with voltage applying means, Represents a display element. It is a schematic diagram which shows the structure which is another aspect of the display element of this invention by the display element manufactured in Example 2. FIG. (A) is a board | substrate with which a pair of electrode was formed, (b) is a display element, (c) is provided with a voltage application means, and represents the display element of a voltage application state. It is a schematic diagram which shows the structure which is another aspect of the display element of this invention by the display element manufactured in Example 3. FIG. (A) is a board | substrate with which a pair of electrode was formed, (b) is a display element, (c) is provided with a voltage application means, and represents the display element of a voltage application state. It is a schematic diagram which shows the structure which has the laminated structure which is another aspect of the display element of this invention with the display element manufactured in Example 5. FIG. (A) is a substrate on which a pair of electrodes are formed, (b) is a display dimming unit cell in which a pair of electrodes are further formed on a display dimming unit cell, and (c) is a stack of display dimming unit cells. A display element (d) represents a display element in a voltage application state in which voltage application means is provided in (c). It is a schematic diagram which shows the structure which is another aspect of the display element of this invention by the display element manufactured in Example 6. FIG. (A) is a display element, (b) is a display element in which a voltage application means is provided in (a) and a voltage is applied. It is a display element manufactured in Example 7, and is a schematic diagram showing a configuration which is still another aspect of the display element of the present invention. (A) is a display element, (b) is a display element in which a voltage application means is provided in (a) and a voltage is applied. It is a schematic diagram which shows the structure which has the laminated structure which is another aspect of the display element of this invention with the display element manufactured in Example 8. FIG. RGB display dimming unit cells are stacked, voltage application means is provided, and the display element is in a voltage application state. It is a schematic diagram which shows the structure which has the parallel structure which is another aspect of the display element of this invention with the display element manufactured in Example 9. FIG. RGB display dimming unit cells are arranged in parallel, provided with voltage application means, and represents a display element in a voltage application state. It is a schematic diagram which shows the structure which has the parallel structure which is another aspect of the display element of this invention with the display element manufactured in Example 10. FIG. (A) is a substrate on which partition walls and electrodes for RGB display dimming unit cells are formed, and (b) is an RGB display dimming unit cell arranged in parallel, provided with voltage applying means, and displaying voltage application state. Represents an element. It is a schematic diagram which shows the structure which is another aspect of the display element of this invention by the display element manufactured in Example 11. FIG. (A) is a display element that shows a dispersed state (blue display) using magnetic particles as mobile fine particles, and (b) is a display element that is provided with magnetic force application means and is in a magnetic force application state (white display).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st board | substrate 1a Thin film 2 1st electrode 4 2nd electrode 5 Insulating layer 6 Partition 7 Adhesion layer 8 2nd board | substrate 9 Insulating liquid 10 Metal colloid particle (R)
11 Metal colloidal particles (G)
12 Metal colloidal particles (B)
20 Magnet 21 Magnetically mobile fine particles

Claims (42)

A display medium comprising a light control layer containing mobile fine particles exhibiting color developability in a dispersed state. The display medium according to claim 1, comprising a plurality of light control unit cells including the light control layer, each of the light control unit cells being stacked on a substrate surface. The display medium according to claim 1, wherein the display medium includes a plurality of dimming unit cells including the dimming layer, and each of the dimming unit cells is arranged in parallel to the substrate surface. The display medium according to claim 2, wherein the plurality of dimming unit cells include a dimming unit cell that exhibits red, a dimming unit cell that exhibits green, and a dimming unit cell that exhibits blue. . The display medium according to claim 1, wherein the mobile fine particles are dispersed in a polymer resin. The display medium according to claim 1, wherein the mobile fine particles are charge mobile fine particles. The display medium according to claim 1, wherein the mobile fine particles are dispersed in a medium whose physical and chemical properties are changed by an external stimulus. The display medium according to claim 7, wherein the external stimulus is an electric field. The display medium according to claim 7, wherein the physical and chemical property is viscosity. The display medium according to claim 6, wherein the charge transferable fine particles have a volume average particle diameter of 1 to 100 nm. The display medium according to claim 6, wherein a particle size distribution of the charge transferable fine particles has one or more maximum peaks, and at least one of the maximum peaks satisfies the following formula (1).
Formula (1) Pp (± 30) / Pp (T) ≦ 0.5
[In the formula (1), Pp (T) means the maximum peak height of the maximum peak, and Pp (± 30) is the particle diameter of the charge-transferring fine particles at the maximum peak height of ± 30%. It means the peak height in particle diameter. ] The display medium according to claim 6, wherein the charge transferable fine particles are metal colloid particles having a plasmon coloring function. The display medium according to claim 12, wherein the metal colloidal particles are gold or silver metal fine particles. 13. The display medium according to claim 12, wherein in the particle size distribution of the metal colloid particles, one peak position (particle diameter) of the maximum peak is 1 to 100 nm. 15. The display medium according to claim 14, wherein in the particle size distribution of the metal colloid particles, one peak position (particle diameter) of the maximum peak is 2 to 70 nm. A display element comprising: a light control layer containing mobile fine particles exhibiting color developability in a dispersed state; and fine particle moving means provided in the vicinity of the light control layer. The display element according to claim 16, wherein the fine particle moving means is a pair of electrodes connected to the light control layer. The display element according to claim 17, wherein a pair of electrodes connected to the light control layer is provided at a part of an outer peripheral end portion of the light control layer. The display element according to claim 16, comprising a plurality of light control unit cells including the light control layer, wherein the plurality of light control unit cells are stacked on a substrate surface. The display element according to claim 17, comprising a plurality of dimming unit cells including the dimming layer, wherein each of the dimming unit cells is arranged in parallel to the substrate surface. 21. The display element according to claim 19, wherein the plurality of dimming unit cells include a dimming unit cell that exhibits red, a dimming unit cell that exhibits green, and a dimming unit cell that exhibits blue. . The display element according to claim 16, wherein the mobile fine particles are dispersed in a polymer resin. The display element according to claim 16, wherein the mobile fine particles are charge-transfer fine particles. The display element according to claim 16, wherein the mobile fine particles are dispersed in a medium whose physical and chemical properties are changed by an external stimulus. The display element according to claim 24, wherein the external stimulus is an electric field. The display device according to claim 24, wherein the physical and chemical property is viscosity. 24. The display element according to claim 23, wherein the charge transporting fine particles have a volume average particle diameter of 1 to 100 nm. 24. The display element according to claim 23, wherein the particle size distribution of the charge transferable fine particles has one or more maximum peaks, and at least one of the maximum peaks satisfies the following formula (1).
Formula (1) Pp (± 30) / Pp (T) ≦ 0.5
[In the formula (1), Pp (T) means the maximum peak height of the maximum peak, and Pp (± 30) is the particle diameter of the charge-transferring fine particles at the maximum peak height of ± 30%. It means the peak height in particle diameter. ] 24. The display element according to claim 23, wherein the charge transferable fine particles are metal colloid particles having a plasmon coloring function. 30. The display element according to claim 29, wherein the metal colloidal particles are gold or silver metal fine particles. 30. The display element according to claim 29, wherein in the particle size distribution of the metal colloid particles, one peak position (particle diameter) of the maximum peak is 1 to 100 nm. 32. The display element according to claim 31, wherein in the particle size distribution of the metal colloid particles, one peak position (particle diameter) of the maximum peak is 2 to 70 nm. A display method using a display medium having a light control layer containing mobile fine particles exhibiting color developability in a dispersed state, wherein the light control layer is colored by the dispersion state of mobile fine particles, and the light control layer includes And a step of transmitting light in a non-dispersed state of the mobile fine particles, and at least one of these steps is selected and displayed. The display method according to claim 33, wherein the light control layer is disposed on a substrate, and the light control layer exhibits a color of the substrate due to a non-dispersed state of mobile fine particles. A display method using a display medium having a light control layer containing mobile fine particles exhibiting color developability in a dispersed state, wherein the light control layer is disposed on a substrate, and the light control layer displaces the mobile fine particles on a substrate surface. 34. The display method according to claim 33, wherein the display is switched by moving in a direction parallel to the display. The display method according to claim 33, wherein the mobile fine particles are charge-transfer fine particles. 37. The display method according to claim 36, wherein the charge transferable fine particles have a volume average particle diameter of 1 to 100 nm. The display method according to claim 36, wherein the particle size distribution of the charge transferable fine particles has one or more maximum peaks, and at least one of the maximum peaks satisfies the following formula (1).
Formula (1) Pp (± 30) / Pp (T) ≦ 0.5
[In the formula (1), Pp (T) means the maximum peak height of the maximum peak, and Pp (± 30) is the particle diameter of the charge-transferring fine particles at the maximum peak height of ± 30%. It means the peak height in particle diameter. ] The display method according to claim 36, wherein the charge transferable fine particles are metal colloidal particles having a plasmon coloring function. 40. The display method according to claim 39, wherein the metal colloidal particles are gold or silver metal fine particles. 40. The display method according to claim 39, wherein in the particle size distribution of the metal colloid particles, one peak position (particle diameter) of the maximum peak is 1 to 100 nm. 42. The display method according to claim 41, wherein in the particle size distribution of the metal colloid particles, one peak position (particle diameter) of the maximum peak is 2 to 70 nm.

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