JP3472969B2 - Magnetophoretic display panel - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a magnetophoretic display panel.

[0002]

2. Description of the Related Art As shown in FIG. 4, a conventional magnetophoretic display panel 10 has two panels facing each other and a panel 11 on the viewing side.
And a panel 12 on the non-viewing side, and a honeycomb-shaped partition wall 14 as shown in FIG. 5 is provided between the panels 11 and 12, and a large number of cells 1 are formed by the panels 11 and 12 and the partition wall 14.
6 is formed. Inside the cell 16, a dispersion liquid 20 including magnetic particles 18, a dispersion medium, a colorant forming a background portion, and, if desired, an extender is enclosed.

When the magnetic pen 22 is stroked from above the panel 11, the magnetic particles 18 attracted by the magnetic force migrate from the panel 12 side and reach the panel 11 side, and the contrast between the dispersion liquid 20 and the magnetic particles 18 is increased. The black and white display is formed by the difference. An erasing magnet 24 is movably provided on the lower surface of the panel 12.

In addition to the black and white magnetophoretic display panel described above, there is also a magnetophoretic display panel capable of color display. In this case, the magnetic particles 18 of the above material and the color resin are kneaded and pulverized. Since the pulverized granulated particles are irregularly shaped with a large number of acute angles, when they are attracted by the magnetic pen 22, they do not come into surface contact with the panel 11 and there is no gap between the panel 11 and the magnetic powder. It is formed. When this was viewed through the panel 11 on the visual side, there was a defect that color particles could be seen in the inner part of the white color of the dispersion liquid, and a color with a haze appeared, resulting in an unclear color display on the whole.

Further, when coloring black irregular shaped particles,
Since the area of the particles is large, it is necessary to apply a large amount of paint, especially for painting the apex of an acute angle. A large amount of paint results in weakening the magnetic force of the magnetic particles, which has a major drawback that a clear image cannot be obtained.

[0006]

DISCLOSURE OF THE INVENTION The present invention eliminates the above-mentioned conventional drawbacks, and is a magnetophoresis method using magnetic particles, which has good responsiveness to magnetic force, good colorability, and does not impair the color of the colorant. A display panel is provided.

[0007]

The magnetophoretic display panel of the present invention has a multi-cell structure between two substrates, in which magnetic particles, a dispersion medium, a colorant, and optionally an extender are added. In the magnetophoretic display panel in which the dispersion liquid of (1) is enclosed, the color magnetic particles in which the surfaces of spherical stainless steel particles having a particle diameter of 150 μm to 350 μm are colored are used.

In the magnetophoretic display panel of the present invention, spherical stainless steel particles produced by a water atomizing method are used as the color magnetic particles.

Further, the magnetophoretic display panel of the present invention uses color magnetic particles in which the surface of spherical stainless steel particles is color-coated with a complex oxide pigment and a specific gravity of 3.0 to 6.5 CGS pigment. Is.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The magnetophoretic display panel of the present invention has a multi-cell structure between two substrates in the same manner as the conventional type, in which magnetic particles, a dispersion medium, a colorant, and a desired material are contained. A dispersion liquid consisting of a bulking agent is enclosed by. As shown in FIG. 1, color magnetic particles 1 in which a colored layer 3 by coloring is formed on the surface of substantially spherical stainless steel particles 2 are used as magnetic particles in this dispersion liquid.

The stainless steel particles 2 are formed of the following components. Carbon C 0.03% or less Silicon Si 0.1% or less Manganese Mn 0.5% or less Sulfur S 0.03% or less Nickel Ni 0.6% or less Phosphorus P 0.04% or less Chromium Cr 11.0% or less Iron It is Fe residue. The cross-sectional shape of the stainless steel particles 2 is almost spherical as shown in FIG. 1, and it is desirable that the surface is as uneven as possible.

The color magnetic particles 1 have a particle size distribution in the range of 150 to 350 μm on the major axis side and an average particle size of 160 to 250 μm. The reason for limiting this value is, for example, that when particles having a particle size of 150 μm or less are applied, there are particles that can be applied to the entire surface and particles that are applied to spots, and they are scattered and incomplete. Also,
When the particles having a size of 350 μm or more are mixed, a large number of irregularly shaped particles are mixed in, and the irregularly shaped particles have uneven coating, resulting in an incomplete finish. Therefore, the color magnetic particles 1 are 150 to 35
It was set in the range of 0 μm.

Further, by the color magnetic particles 1 to form as described above, when measured by a particle counter, an apparent density of 1.60g ^/ cm ³ ~4.99g ^/ cm 3, and the saturation magnetization is also magnetophoresis Optimal for display panel 150 emu / g ~
It could be in the range of 450 emu / g.

The spherical stainless steel particles 2 forming the color magnetic particles 1 are those produced by a water atomizing method. The water atomization method is a method in which high-pressure water is injected into a molten stainless steel with a large number of injection nozzles, atomized in a water atomizer, and surface tension is caused by the physical properties of the molten metal to form a spherical shape. It should be noted that a sieved product is used to obtain the average particle size.

Next, the colored layer 3 formed on the surface of the substantially spherical stainless steel particles 2 will be described. The reason why the specific gravity of the complex oxide-based pigment is limited to a value of 3.0 to 6.5 CGS is, for example, when the surface of the stainless steel particles 2 is coated with a tumbling flow device, a specific gravity of 3.0 CGS.
The following paints cannot be applied in the tumbling flow device pot because the injected paint does not fly in the air and entangle with the magnetic particles. Further, the coating material having 6.5 CGS or more sinks on the bottom of the pot of the rolling flow device and does not get entangled with the magnetic particles, so that the coating cannot be performed. Therefore, the specific gravity of the composite oxide-based pigment is set in the range of 3.0 to 6.5 CGS. The composite oxide pigment is excellent in oil resistance, water resistance, chemical resistance, and is also difficult in peeling.

Next, the following pigments are used for each color of blue, yellow, green and red mixed in the above paint. That is, yellow pigments ... Cobalt oxide, titanium oxide, and nitrite oxide. Green pigment: Titanium oxide, cobalt oxide, nitrite, zinc oxide. Blue pigment: Cobalt oxide, aluminum oxide. Red pigment: Iron oxide. A clear pigment specific gravity of 3.0 to 6.5 CGS could be obtained with the above physical properties.

In the coating, the stainless steel particles 2 of magnetic particles are put in a rolling fluid device and blown by air in the device to roll. Here, after the magnetic particles have been wetted, they are made into a compact sphere by adsorbing the powder of the coating material. It is dried and then taken out from the tumbling fluidizer. The spray pigment liquid used for the above coating is pigment 2
3%, titanium oxide 2%, resin liquid 37%, water 38%, and a small amount of additives. The coating liquid is 50% resin liquid,
50% water.

Since the color magnetic particles 1 manufactured as described above are made of stainless steel, their saturation magnetization is about 10% lower than that of ferrite or the like. This is because the magnetic force of the magnetic pen is Alternatively, it can be dealt with by increasing the amount by 20% using neodymium iron boron. Further, since it is made of stainless steel, the background color is light, and it is possible to display the colorant without originally impairing it even if it is not covered with the white silver hiding film.

Since the particles of the color magnetic particles 1 are spherical, the surface area is small, the magnetic sensitivity is better than that of the irregular-shaped particles having an acute angle, the adhesion of the paint is good, and the rust is attached. Since it is difficult to remove, there is an advantage that the paint does not peel off due to use and the deterioration with time is small.

FIG. 2 shows a structural example of a magnetophoretic display panel using the color magnetic particles 1 of the present invention. FIG. 3A shows a multi-cell structure between two substrates, in which red dispersion liquid 31 in which red color magnetic particles are mixed, yellow dispersion liquid 32 in which yellow color magnetic particles are mixed, and blue dispersion liquid This is a display panel in which a blue-yellow dispersion liquid 33 containing color magnetic particles and a green dispersion liquid 34 containing green color magnetic particles are arranged side by side in the vertical direction. Similarly, (b) is a red dispersion liquid 31, a yellow dispersion liquid 32, and a blue-yellow dispersion liquid 3
3 shows a configuration example of a display panel in which the green dispersed liquid 34 is arranged side by side in the lateral direction.

FIG. 3 shows the color development when the hiragana "to" is drawn with a magnetic pen on the magnetophoretic display panel of FIG. That is, in (c) of FIG. 3, the letters “to” are displayed, which are color-coded in order from the top, corresponding to the arrangement of each color-dispersed liquid on the display panel. Similarly, in (d), the letters "to" are displayed side by side and color-coded.

[0022]

EXAMPLE The apparent density of the above color magnetic particles is 3.99 g.
/ Cm ³ and the saturation magnetization was 200 emu / g.

[0023]

As described above, according to the magnetophoretic display panel of the present invention, since spherical colored stainless steel particles whose surfaces are colored are used as the magnetic particles, the spherical colored magnetic particles attracted by the magnetic pen are visible. The panels are lined up in order on the back side of the panel without difficulty. As a result, the background color is lighter than that of the conventional one using ferrite or magnetite, and the original color of the color paint can be visually recognized. Also,
Since the color magnetic particles are spherical, the surface area is small, the responsiveness to the magnetic force of the magnetic pen is good, the adhesion of the color paint at the time of painting is good, it is hard to rust, the paint does not peel off due to use, and deterioration over time Can be reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of color magnetic particles used in a magnetophoretic display panel showing an embodiment of the present invention.

FIG. 2 is a plan view showing an arrangement example of color magnetic particles of the magnetophoretic display panel of the present invention.

FIG. 3 is a plan view showing a coloring example of characters drawn on the magnetophoretic display panel of the present invention.

FIG. 4 is a sectional view of a main part of a conventional magnetophoretic display panel.

FIG. 5 is a cross-sectional view of a main part of a partition in a conventional magnetophoretic display panel.

[Explanation of symbols]

1 color magnetic particles 2 spherical stainless steel particles 3 colored layers 10 Magnetophoretic display panel 11 Viewing side panel 12 Non-visual side panel 14 partitions 16 cells 18 magnetic particles 20 dispersion liquid 22 Magnetic pen 24 erasing magnet 31 red dispersion liquid 32 Yellow dispersion liquid 33 Yellow dispersion liquid 34 Green dispersion liquid

Claims (3)

(57) [Claims] 1. A magnetophoretic display panel having a multi-cell structure between two substrates, in which a dispersion liquid composed of magnetic particles, a dispersion medium, a coloring agent, and optionally an extender is enclosed. A magnetophoretic display panel characterized by using colored magnetic particles colored on the surface of spherical stainless steel particles having a particle diameter of 150 μm to 350 μm. 2. The magnetophoretic display panel according to claim 1, wherein spherical magnetic particles made of water are used as the color magnetic particles. 3. The magnetic particles according to claim 1, wherein spherical magnetic particles are used which are colored with a complex oxide pigment and a specific gravity of 3.0 to 6.5 CGS pigment on the surface of spherical stainless steel particles. Electrophoresis display panel.