JP3382532B2 - 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 Conventionally, between two substrates (panels), a multi-cell structure is formed, and in these cells, magnetic particles made of magnetite, ferrite, etc., a dispersion medium, and a colorant which constitutes a background. There is known a magnetophoretic display panel in which a dispersion fluid containing a thickening agent is enclosed if desired.

In this magnetophoretic display panel, when the front substrate surface is traced with a magnetic pen, the magnetic particles attracted by the magnetic force of the magnetic pen migrate from the back substrate to reach the front substrate, and the dispersed fluid is generated. The black and white display is formed by the difference in contrast between the magnetic particles and the magnetic particles.

FIG. 1 shows a part of a conventionally used magnetophoretic display panel 10. Note that (a) is a cross-sectional view and (b) is a plan view. As shown in the figure, the magnetophoretic display panel 10 has two non-magnetic panels 12a and 12b facing each other, the panel 12a being the viewing side and the panel 12b being the non-viewing side. These panels 12
A large number of partition walls 14 are provided between a and 12b,
A large number of honeycomb type cells 16 are formed by the partition walls 14 and the panels 12a and 12b. Normally, the panel 12a has a thickness of 0.2 to 0.3 mm, the partition wall 14 has a height of 0.5 to 1.5 mm, the panel 12b has a thickness of 0.1 mm, and the cell 16 has a maximum width of about 4 mm .

Inside the cell 16, magnetic particles 18
A dispersion fluid 20 composed of a dispersion medium, a colorant forming a background portion, and optionally a thickener is enclosed, and when tracing the surface of the panel 12a on the visual side with a magnetic pen 22,
The magnetic particles 18 are attracted and migrate to reach the back surface of the panel 12a, and due to the difference in color between the colorant forming the background and the magnetic particles, characters or the like traced by the magnetic pen 22 are displayed on the surface of the panel 12a. In general, the ground color of the magnetic particles 18 is black or dark brown, so that the colorant forming the background is made white to display black and white.

Next, in order to erase the characters or the like once displayed, the erasing magnet 24 arranged on the back surface of the panel 12b on the non-viewing side is slid along the surface of the panel 12b. Then, the magnetic particles 18 attracted to the back surface of the panel 12a migrate to the panel 12b this time, and when viewed from the panel 12a side, only the color of the dispersed fluid 20 is visible and the display of characters and the like is erased. It was done. The panel 12a uses an opaque light diffusing plate such as white so that the color of the magnetic particles 18 cannot be seen through when viewed from the viewer side.

In recent years, there is an increasing demand for color display in addition to the black-and-white display, so that magnetic particles of the above-mentioned materials are colored by electro-deposition, vapor deposition or spraying with a pigment or the like for color display. Some have been done.

[0008]

However, when the above-mentioned magnetic particles are used, since these magnetic materials are black to dark brown, they are suitable for obtaining a black-and-white display. Is not suitable for color display. Further, generally, since spherical particles are used as these magnetic particles, the coloring property cannot be said to be sufficient, the coloring agent is easily peeled off, and the response to magnetic force is not always sufficient.

An object of the present invention is to provide a magnetophoretic display panel using magnetic particles that have good responsiveness to magnetic force, good colorability, and do not impair the color of the colorant.

[0010]

In order to solve the above problems, the present invention employs the following means. The magnetophoretic display panel according to claim 1, wherein the two substrates are formed into a multi-cell structure, and the surfaces of the cells are colored in color.
Magnetic particles made of stainless steel particles variants were, and a dispersion medium, a coloring agent constituting a background portion, wherein the encapsulating dispersed fluid comprising the desired thickener.

The magnetophoretic display panel according to claim 2 is
In the invention according to claim 1, the multi-cell structure is a honeycomb
It is characterized by being a mu- type.

The magnetophoretic display panel according to claim 3 is
In the invention described in claim 1, the multi-cell structure is a microcapsule type.

[0013]

With the above arrangement, the response of the magnetophoretic display panel to the magnetic pen is improved. It can be said that this is due to the large surface area of the irregular-shaped magnetic particles. Further, since the magnetic particles are irregular, the colorability of the color paint is good, and the peeling of the paint due to use is small, so that there is the advantage that there is little deterioration over time, and the ground color of stainless steel particles is used. Therefore, the original color of the color paint can be visually recognized as compared with ferrite or magnetite, and vivid color display can be performed.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of the present invention will be described below with reference to the drawings. In addition, the same or equivalent members as those described in the section of the related art will be described with the same reference numerals.

The external appearance of the magnetophoretic display panel 10 according to the present invention is the same as that of the conventional one shown in FIG. 1, and therefore will be described with reference to FIG. As shown in the figure, this magnetophoretic display panel 10 also has two non-magnetic panels 12a and 12b that face each other like the conventional one.
Is the visual side and the panel 12b is the non-visual side. A large number of partition walls 14 are provided between the panels 12a and 12b, and a large number of honeycomb cells 16 are formed by the partition walls 14 and the panels 12a and 12b.

Inside the cell 16, a dispersion fluid 20 composed of magnetic particles 18, a dispersion medium, a colorant forming a background portion, and optionally a thickener is enclosed, and the viewing side panel 12a. When the surface of the magnetic particle 18 is traced with the magnetic pen 22, the magnetic particles 18 are attracted and migrate to reach the back surface of the panel 12a, and due to the color difference between the colorant for displaying the background and the magnetic particles 18, the magnetic pen 18 is applied to the surface of the magnetic pen. The characters and the like traced in 22 are displayed.

Next, the magnetic particles 18 used here
Will be described. The magnetic particles 18 are stainless steel particles, and their components are: carbon C ... 0.03% or less, silicon Si ... 1.5% or less, manganese Mn ... 0.3% or less, phosphorus P ... 0.04% or less Sulfur S ... 0.03% or less, Nickel Ni ... 0.6% or less Chromium Cr ... 11.5 to 13.5% Iron Fe ...

Its shape is as shown in the sectional view of FIG.
It is a variant. Here, the irregular shape means that the shape of particles is not unified into a specific shape such as a spherical shape or a substantially rectangular parallelepiped shape, and each particle has a different shape.
Further, it is preferable that the surface is formed by a complicated uneven surface.

The particle size is measured on the major axis side,
It is distributed in the range of 30 to 100 μm, and the average particle size is 7
It is 0 to 75 μm.

The magnetic particles 18 are made of stainless steel composed of the above-mentioned components. The magnetic particles 18 are manufactured by the water atomizing method in order to make the particles different in shape. The water atomizing method is a method in which high-pressure water is sprayed on molten steel to be powdered. Since the range of the size distribution of the particles produced by this method is wide, in order to determine the range as described above, it is sieved to remove other portions.

Next, color coloring of the magnetic particles 18 will be described. An acrylic resin paint is used as the paint. Polyurethane-based, epoxy-based, or vinyl chloride-based may be used, but acrylic-based is superior in that it is less likely to peel off, has good gloss, and has good water and oil resistance.

Next, the pigment mixed in the paint will be described. The pigment was used for four colors of blue, yellow, green and red. Blue pigment: Fine particles of melamine / toluenesulfonamide resin colored with a fluorescent dye, good solvent resistance and clear color. Yellow pigment: chrome yellow (PbCrO4), an inorganic pigment mainly composed of chrome zinc, and has a large coloring power and hiding power. Green pigment: Chromium oxide (Cr2O3), an inorganic pigment that is highly stable against chemicals. Red pigment: Azo organic pigment. Acetone and toluene were used as the solvent.

The coloring of the magnetic particles 18 is performed by a spray dryer method, the drying temperature is 130 ± 2 ° C., and the drying time is 3 seconds. No pretreatment was performed. As a result, a colored coating film having a thickness of 20 to 30 μm was formed on the surface of the magnetic particles 18. Incidentally, instead of the above pigment, ultramarine blue, aniline blue, DuPont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue,
A pigment or dye such as phthalocyanine green can also be used.

Magnetic particles 18 produced as described above
Since the material is stainless steel, the saturation magnetization is about 10% lower than that of ferrite or the like, but this point can be dealt with by increasing the magnetic force of the magnetic pen by 20%. Since it is made of stainless steel, the background color is light and the colorant color can be displayed without impairing the original color even if it is not covered with a white silvery hiding film or the like. Further, since the magnetic particles 18 are irregularly shaped, the magnetic sensitivity is better than that of the spherical particles, the adhesion of the paint is good, and the rust is less likely to occur. is there.

Further, by coloring the magnetic particles 18 as described above, the heat resistance characteristics are improved.
While the magnetic particles solidify into a mass at a temperature of 0 ° C., such a phenomenon is not observed in the case of the magnetic particles 18 of the present embodiment.

Next, regarding the second embodiment of the present invention,
A description will be given with reference to the drawings. The same or equivalent members as those described in the first embodiment are designated by the same reference numerals.

As shown in FIG. 3, the magnetophoretic display panel 30 according to the second embodiment has two nonmagnetic panels 12a and 12b facing each other. The panel 12a is the viewing side and the panel 12b is the viewing side. It is the non-visual side. These panels 12
A large number of spherical microcapsules 26 are housed between a and 12b, and the microcapsules 26 form a multi-cell structure. Inside the microcapsules 26, the honeycomb- shaped cells 16 in the first embodiment are provided.
The same as that enclosed inside, that is, a dispersion fluid 20 composed of irregularly shaped magnetic particles 18 made of colored stainless steel, a dispersion medium, a colorant forming a background portion, and a thickener if desired. It is enclosed.

The microcapsules 26 are composed of magnetic particles 18
A dispersion fluid 20 comprising a dispersion medium, a colorant forming the background portion, and a thickener if desired, and the dispersion fluid 20.
It is composed of a shell material such as a polymer that covers the. The resin used as the shell material generally includes acrylic resin, methacrylic resin, polystyrene resin, polyester resin, polyurethane resin, polyamide resin, epoxy resin, etc. Alternatively, they are used as a mixture.

The method for producing the microcapsules 26 is a phase separation method in which a concentrated layer of polymer is separated around a dispersion fluid 20 which becomes a core substance dispersed in a polymer solution, and a polymer is dispersed around a core substance in a polymer solution. In-liquid curing coating method, in which the polymer is cured with a curing test agent, etc., an in-situ weight that coats the surface of the core substance with the polymer by supplying the monomer or polymerization catalyst from either the external phase or the emulsion in which the core substance is dispersed. There is legality etc. In particular, the phase separation method,
According to the in-situ polymerization method, the magnetic particles 1 have a uniform particle size.
It is possible to manufacture the microcapsules 26 that can be easily moved.

When the surface of the thus-formed magnetophoretic display panel 30 on the viewing side of the panel 12a is traced with the magnetic pen 22, the magnetic particles 18 are attracted and the microcapsules 2 are attracted.
6 inside, and microcapsules 26 on the side of panel 12a
Colorant and magnetic particles that reach the back side and display the background 1
Characters and the like traced by the magnetic pen 22 are displayed on the surface of the panel 12a due to the difference in color from the color of No. 8. The panel 12a uses an opaque light diffusing plate such as white so that the color of the magnetic particles 18 cannot be seen through when viewed from the viewer side.

Next, in order to erase the characters or the like once displayed, the erasing magnet 24 disposed on the back surface of the non-viewing side panel 12b is slid along the surface of the panel 12b. Then, the magnetic particles 18 attracted to the back surface of the microcapsule 26 on the panel 12a side migrate inside the microcapsule 26 in the direction of the panel 12b, reach the back surface of the microcapsule 26 on the panel 12b side, and reach the panel 12a. When viewed from the side, only the color of the dispersed fluid 20 can be seen, and the display of characters and the like is erased.

[0032]

As described above, according to the present invention,
Magnetophoretic display in which a multi-cell structure is formed between two substrates, and a dispersion fluid consisting of magnetic particles, a dispersion medium, a colorant forming a background portion, and optionally a thickener is enclosed in these cells. In the panel, the magnetic particles are colored on the surface.
-Because colored irregular shaped stainless steel particles are used,
The ground color is lighter than that of ferrite or magnetite, and the original color of the color paint can be visually recognized, and vivid color display can be performed. In addition, since the magnetic particles are irregular, the response to the magnet is good, the adhesion of the color paint is good, and the paint is less likely to rust, so that the paint does not peel off due to use and deterioration over time can be reduced.

[Brief description of drawings]

FIG. 1 shows a part of a magnetophoretic display panel which has been used conventionally and is also a first embodiment of the present invention, (a) is a sectional view, and (b) is a plan view.

FIG. 2 is a cross-sectional view of color-shaped irregular-shaped magnetic particles.

FIG. 3 is a sectional view showing a second embodiment of the present invention.

[Explanation of symbols]

10 Magnetophoretic display panel 12a Viewing side panel 12b Non-visual side panel 14 partitions 16 cells 18 magnetic particles 20 dispersed fluid 22 Magnetic pen 24 permanent magnet 26 macro capsules 30 Magnetophoretic display panel

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G09F 9/37 B43L 1/00

Claims (3)

(57) [Claims] 1. A multi-cell structure is formed between two substrates, and magnetic particles composed of irregularly shaped stainless steel particles having a colored surface are formed in these cells, a dispersion medium, and a background portion. A magnetophoretic display panel, characterized in that a dispersion fluid comprising a colorant and, if desired, a thickener is enclosed. 2. The magnetophoretic display panel according to claim 1, wherein the multi-cell structure is a honeycomb type. 3. The magnetophoretic display panel according to claim 1, wherein the multi-cell structure is a microcapsule type.