JPH08324107A - Magnetic display type recycle sheet - Google Patents

Abstract

PURPOSE: To provide a magnetic display type recycle sheet excellent in friction resistance and repeating resistance because non-contact printing can be performed by heat and magnetism, showing clear light and darkness by the difference between a heat and magnetism applied part and a non-applied part, excellent in visibility and image stability and made possible in reversible display. CONSTITUTION: In a magnetic display recycle sheet 10 having a magnetic display layer 12 composed of a rewritable reversible material and capable of repeatedly erasing printing, the magnetic display layer 12 wherein microencapsulated display particles 13 formed by including at least a flaky magnetic powder 15 in a dispersing medium 16 solid at the normal temp. is dispersed in a binder 14 on a support 11 composed of a non-magnetic material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information recording paper on which an image is repeatedly displayed by heat and magnetism. More specifically, it is excellent in repeat resistance, visibility and image stability, and particularly in a paper-like shape. The present invention relates to a reversible magnetic display type recycling sheet.

[0002]

2. Description of the Related Art Conventionally, pressure-sensitive recording paper, heat-sensitive recording paper, electrostatic recording paper and the like have been known as information recording paper.
However, these recording methods cannot repeatedly use the recording paper. Therefore, repetitive use of recording paper, that is, a recording method capable of reversible display of print erasure has attracted attention. So far, as a display method capable of reversible display,
There are known a display method using transparency / opacity due to a phase change of an organic low molecule and a polymer, a method utilizing a chemical change of coloring / decoloring of a leuco dye and a developer / decolorizer, or a display method utilizing magnetism.

First, the method using organic small molecules and polymers is
As described in Japanese Patent Application Laid-Open No. 4-112079, a change in transparency or opacity occurs due to a phase change of an organic low molecule with temperature, and visible information can be displayed.
That is, by controlling the applied temperature, transparent and opaque repeats occur, and repeated printing becomes possible. However, with this display method, the contrast between the recorded visible image and the background is low, heating for a long time is required to erase the visible image, and because direct printing is performed with a thermal head, etc. Had a sex problem.

In addition, coloring with a leuco dye and a developer / decolorizer
A method of displaying by erasing is described in Japanese Patent Laid-Open No. 5-139080
As described in Japanese Patent Laid-Open Publication No. JP-A No. 2004-187, visible information can be displayed by coloring / decoloring the leuco dye due to the difference in chemical change between the leuco dye and the developer / color fading agent depending on the temperature. Repeated printing and decoloring enables repeated printing. However, this display method requires heating for a long time at the time of erasing, and has a defect in light resistance and heat resistance of a recorded visible image.

Further, as a display method utilizing magnetism,
For example, Japanese Patent Laid-Open Nos. 2-146082 and 4-2.
As described in Japanese Patent No. 33581, a display medium is known in which light-absorbing magnetic particles and light-reflecting non-magnetic particles are encapsulated in microcapsules. In the image formation of this form, first, the permanent magnet attracts the light-absorbing magnetic particles in the microcapsules to the back surface side of the display medium, and accordingly, the light-reflecting non-magnetic particles are formed on the surface of the display medium. By remaining, the surface becomes the color of non-magnetic particles,
Erase state. Next, by applying and recording magnetism from the surface of the display medium with a permanent magnet, the light absorbing magnetic particles are magnetically attracted to the surface, and desired characters and images are formed. However, the display medium thus obtained has a magnetic force over a wide range, and therefore has a resolution extremely inferior to that of recording by other heat or light. Further, since the above-mentioned display medium can be easily printed or erased by magnetic force, the stability of the image may be deteriorated such that the fogging of the unprinted portion may occur or the image may be erased just by touching the magnet. Has the disadvantage of being bad.

[0006]

From the above, in order to be used as a repeatedly usable information recording paper, it is necessary to have durability against friction and the like received from the printing means and the sharpness and image stability of the printed image. However, the conventional reversible display method has a problem in abrasion resistance such as dust adhesion due to direct printing of a thermal head, etc. Further, the displayed image is partially affected by heat or magnetism from the outside. Alternatively, it was not possible to perform stable recording because the image was erased in an unreadable state or fogging occurred in the unprinted portion, and the temperature control was difficult at the time of erasing the record. Further, there is a problem in durability against repeated printing and erasing.
Therefore, since the present invention can perform non-contact printing by heat and magnetism, it is excellent in abrasion resistance and repeatability, and the portion to which heat and magnetism is applied has a clear contrast between darkness and darkness as compared to the non-application portion. It is an object of the present invention to provide a magnetic display type recycle sheet capable of reversible display, which is excellent in stability and image stability.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above object, and the invention according to claim 1 is repeated printing erasure provided with a magnetic display layer made of a rewritable rewritable material. In the magnetic display type recording medium capable of achieving the above, the magnetic display layer includes at least a flake-like magnetic powder on a support made of a non-magnetic material and a dispersion medium which is in a solid state at room temperature and is formed by dispersing the magnetic powder. The micro-encapsulated display particles are dispersed in a binder.

The invention according to claim 2 is characterized in that the flaky magnetic powder has an average major axis of 10 to 20 μm and a thickness of 0.1 to 2 μm and a coercive force of 1000 Oe or less. .

According to a third aspect of the present invention, the support is made of an opaque non-magnetic material and a paper or plastic sheet having a thickness of 10 to 100 μm.

The invention according to claim 4 is characterized in that the dispersion medium comprises an organic compound having a melting point of 35 ° C. or higher and 80 ° C. or lower.

According to a fifth aspect of the invention, the binder is
It is characterized by being made of a thermosetting resin.

[0012]

The magnetic display type recycle sheet of the present invention is a recycle sheet which can be repeatedly erased and printed, and in particular has a paper-like shape, and contains a dispersion medium in which flake-like magnetic powder is dispersed and which shows a solid state at room temperature. It has a magnetic display layer containing microencapsulated display particles encapsulated, usually,
The flaky magnetic powder is oriented along the surface of the magnetic display layer and reflects light, so that the surface of the recycled sheet has a uniform color tone of metallic luster. In addition, the flake-shaped magnetic powder is oriented perpendicular to the recycled sheet surface by the action of heat and magnetism for the recording of information, only the oriented portion absorbs light, and the display surface forms a black image in the metallic luster. By doing so, you can read the information.

[0013]

The present invention will be described in detail below with reference to the drawings. FIG. 1 is an explanatory view showing a cross section of an embodiment of the magnetic display type recycling sheet of the present invention. FIG. 2 is an explanatory view showing in cross section the state of the magnetic display type recycled sheet of the present invention during manufacturing, and FIG. 3 shows an unrecorded state by the erasing operation of the magnetic display type recycled sheet of the present invention. FIG. 4 is an explanatory view in cross section, and FIG. 4 is an explanatory view in cross section showing a state of the magnetic display type recycling sheet of the present invention during recording.

FIG. 1 shows the constitution of a magnetic display type recycling sheet (10) of the present invention, in which a microcapsule display particle (13) containing magnetic powder or the like is bound on a support (11) as a binder (14). A magnetic display layer (12) was obtained by applying the coating agent dispersed in the above. Here, the microencapsulated display particles containing the flake-like magnetic powder (15) used in the present invention are obtained by dispersing the flake-like magnetic powder in a dispersion medium (16) (for example, wax) which exhibits a solid state at room temperature. It was prepared by dispersing and encapsulating it in a size of 20 μm or more and 100 μm or less. First, as the flake-shaped magnetic powder (15), magnetic powder alone or a mixture of several magnetic powders can be used. Examples include magnetite, ferrite, and other metals exhibiting soft magnetism such as iron, cobalt, and nickel, alloys containing these elements, and flaky magnetic powders of compounds. In this case, the flaky magnetic powder may be subjected to surface hydrophobizing treatment such as silane coupling treatment in order to enhance affinity with wax or the like. The size of the flake-like magnetic powder is preferably in the range of 10 to 20 μm in major axis and 0.1 to 2 μm in thickness, considering the ease of orientation by magnetism and the image density as recording paper. When the major axis of the flaky magnetic powder is 10 μm or less or 20 μm or more, the contrast between the recording portion and the base becomes low, and the image density as recording paper cannot be obtained. Furthermore, considering the easiness of response to magnetism, the coercive force, which is one of the magnetic characteristics, is 10
It is preferably set to 00 Oe or less. Coercive force is 1000 Oe
If it is above, the response to the perpendicular magnetism or the horizontal magnetism becomes sluggish, and it takes a long time to erase the print.

The dispersion medium (16) is at room temperature (about 10 ° C.).
A solid (in the solid phase state) in the range of up to 35 ° C.,
In addition, it may be in a fluidized state when heated to a temperature higher than room temperature (in the range of about 40 ° C. to 80 ° C.). For example, organic compounds such as synthetic waxes such as paraffin wax and polyethylene wax, and carnauba. Natural waxes such as wax and petrolatum, natural and synthetic resins, butyl stearate, methyl stearate, higher fatty acid esters such as myristyl myristate and stearyl myristate, higher alcohols such as dodecyl alcohol, stearyl alcohol and myristyl alcohol, etc. Those generally known that satisfy the above conditions can be used alone or in combination as appropriate.

As a method for preparing the microencapsulated display particles (13) containing magnetic powder and the like, the above-mentioned flake-like magnetic powder is dispersed in a dispersion medium which is in a solid state at room temperature.
After being dispersed at a temperature equal to or higher than the melting point of the dispersion medium, it is emulsified in a gelatin-arabic gum aqueous solution and microencapsulated to form microencapsulated display particles. The size of the microcapsules is preferably 20 μm or more and 100 μm or less. If the size of the microcapsules is 20 μm or less or 100 μm or more, the contrast between the recording portion and the base becomes low, and the image density as recording paper cannot be obtained.

The binder (14) in which the microencapsulated display particles are dispersedly arranged is a thermosetting water-based emulsion resin, and examples thereof include polyurethane resin, polyester resin and epoxy resin. This binder is required to hold and protect the microencapsulated display particles formed on the support, and to have transparency such that the microencapsulated display particles can be seen from the outside, and necessary conditions such as strength. Any material can be used as long as it satisfies the requirements.

Next, as the support (11) made of an opaque non-magnetic material, for example, polyester film, polypropylene film, polyimide film,
Examples thereof include plastic films such as polyethylene terephthalate film, plain paper, synthetic paper and the like. The thickness of the support is preferably 100 μm or less. When the thickness of the support is 100 μm or more, it becomes difficult to use it as a paper-like recording paper. The surface on which the magnetic display layer is provided is colored black.

Further, the recording on the magnetic display type recycling sheet of the present invention is carried out, for example, by scanning from the surface side with a magnetism generating means having a heating means, and the viscosity is lowered by heat to a dispersion medium in a fluidized state. The dispersed flake-like magnetic powder is oriented along the perpendicular magnetic field, and an image is formed by the flake-like magnetic powder in the microencapsulated display particles. Further, in erasing, the entire surface is heated and horizontal magnetism is given, or the surface is scanned by a magnetism generating means having a heating means, so that the flaky magnetic powder is oriented along the horizontal magnetism, and the visible display portion The surface of is again in uniform color and the image is erased. However, the method is not limited to this. Since this image formation is simple due to heat of low energy enough to reduce the magnetism and the viscosity of the dispersion medium,
Recording is easy, and by controlling the size of microencapsulated display particles in which magnetic powder or the like is dispersed and arranged, it is possible to form an image with high resolution. Furthermore, the image formed by the thermal / magnetic head device with a heating function has good recording stability because the dispersion medium returns to room temperature and becomes fixed at the same time. Since it cannot be formed, no fogging occurs even if the magnet touches it. The magnetic display type recycling sheet according to the present invention has the orientation of the flaky magnetic powder dispersed in the microencapsulated display particles at the time of recording, that is, both the good response of the magnetic recording and the stability of the recorded image. Is. In addition, since the magnetic powder can be oriented only in the portion of the dispersion medium that is in a fluidized state by heating, the contrast between the recorded visible image and the ground is high and the visibility is excellent. Since such a magnetic display type recycling sheet (10) can be repeatedly printed and erased and is paper-like, it is used as, for example, facsimile paper, recording paper for various measuring instruments, printing paper for word processors, etc. Can be reused,
It also reduces paper waste from the office and saves resources.

Next, an image forming method for the magnetic display type recycle sheet of the present invention will be described. FIG. 2 shows a mixed liquid of microencapsulated display particles in which flaky magnetic powder is dispersed in a dispersion medium and a thermosetting resin, which is applied on a support.
It is explanatory drawing which expanded a part of magnetic display part of this invention. At the time of production, the flake-shaped magnetic powder is fixed in the dispersion medium in a state of being uniformly dispersed in the microencapsulated display particles. Further, FIG. 3 is an explanatory diagram showing a state when a normal image is erased or when no image is recorded. For erasing, the entire surface is heated and horizontal magnetism is applied, or the surface is scanned by a magnetism generating means having a heating means, whereby the dispersion medium in the microencapsulated display particles becomes in a molten state and the applied horizontal The flaky magnetic powder is oriented along the magnetism and reflects light, so that the surface of the visible display portion has a uniform color tone of metallic luster. Further, FIG. 4 is an explanatory diagram showing a state in which recording is performed from the surface of the magnetic display type recycle sheet by applying perpendicular magnetism of the magnetism generating means having a heating function. The viscosity of the dispersion medium in the microencapsulated display particles at the portion heated by the heat / magnetic head device, which is a magnetism generating means with a heating function, decreases to a fluid state, and it is dispersed in the dispersion medium along the perpendicular magnetic field. The flaky magnetic powder is oriented and an image is formed. On the other hand, there is no orientation of the flaky magnetic powder in the microencapsulated display particles in the portion that is not heated by the thermal / magnetic head device. Therefore, by heating and magnetically applying the recording portion in accordance with the recording information, a black image can be obtained in the recorded portion in the uniform color tone of the unrecorded portion. In this thermal / magnetic head device, a heating means such as a heater is added to an ordinary magnetic head, and the heating means may have a heating capacity enough to melt the above-mentioned dispersion medium such as wax.

Specific examples will be described below.

Example 1 Flake-like magnetic powder (major axis 10
A soft magnetic iron powder having a thickness of 1 μm and a thickness of 1 μm) was subjected to a silane coupling treatment with trimethoxychlorosilane to make the surface of the magnetic powder hydrophobic. Next, the flaky magnetic powder was sufficiently dispersed in carnauba wax (melting point 55 ° C.) under heating at 70 ° C. After that, it is emulsified in an aqueous solution of gum arabic and mixed with an aqueous solution of gelatin, heated to 40 ° C., acetic acid is added dropwise, the entire reaction system is cooled, formaldehyde is added dropwise to cure the wall material, and the flaky magnetic powder is added. A microcapsule having a size of 30 to 40 μm and containing a dispersion medium was prepared, and microcapsulated display particles were prepared. The microencapsulated display particles were dispersed in a urethane resin / isocyanate emulsion aqueous solution to give a thickness of 20.
Apply it to a thickness of 60 μm on a plain paper of μm, and
It was dried at 0 ° C. for 1 hour to produce a magnetic display type recycled sheet. By heating this magnetic display type recycling sheet and applying horizontal magnetism, the surface of the magnetic display type recycling sheet exhibited a metallic luster color. When a magnetic head having a heating means was used to apply heat and perpendicular magnetism, the magnetic display type recycled sheet could obtain a black image.

Example 2 Flake-shaped magnetic powder (major axis 15)
silane coupling treatment of a soft magnetic iron-nickel alloy having a thickness of 1 μm with trimethoxychlorosilane,
The hydrophobic treatment of the magnetic powder was performed. Next, the flaky magnetic powder was sufficiently dispersed with dodecyl carboxylate (melting point 70 ° C.) under heating at 80 ° C. After that, it is emulsified in an aqueous solution of gum arabic and mixed with an aqueous solution of gelatin, heated to 40 ° C., acetic acid is added dropwise, the entire reaction system is cooled, formaldehyde is added dropwise to cure the wall material, and the flaky magnetic powder is added. A microcapsule having a size of 50 to 60 μm and containing a dispersion medium was prepared, and microcapsulated display particles were produced. The microencapsulated display particles were dispersed in an epoxy / polyamide emulsion aqueous solution to give a thickness of 40 μm.
On synthetic paper of 80μm thickness, 50 ℃
And dried for 1 hour to prepare a magnetic display type recycled sheet. By heating this magnetic display type recycling sheet and applying horizontal magnetism, the surface of the magnetic display type recycling sheet exhibited a metallic luster color. When a magnetic head having a heating means was used to apply heat and perpendicular magnetism, the magnetic display type recycled sheet could obtain a black image.

<Comparative Example 1> Flake-shaped magnetic powder (major axis 15
A soft magnetic nickel powder having a thickness of 1 μm and a thickness of 1 μm was subjected to a silane coupling treatment with trimethoxychlorosilane to hydrophobize the magnetic powder. Next, the flaky magnetic powder was sufficiently dispersed with dodecyl carboxylate (melting point 70 ° C.) under heating at 80 ° C. After that, it is emulsified in an aqueous solution of gum arabic and mixed with an aqueous solution of gelatin, heated to 40 ° C., acetic acid is added dropwise, the entire reaction system is cooled, formaldehyde is added dropwise to cure the wall material, and the flaky magnetic powder is added. A microcapsule having a size of 50 to 80 μm and containing a dispersion medium was prepared, and microcapsulated display particles were produced.
The microencapsulated display particles were dispersed in an aqueous polyester emulsion solution, coated on a synthetic paper having a thickness of 20 μm to a thickness of 100 μm, and dried at 50 ° C. for 1 hour to prepare a magnetic display type recycled sheet. By heating the magnetic display recycled paper and applying horizontal magnetism, the surface of the magnetic display type recycled sheet showed a metallic luster color. When a magnetic head having a heating means was used to apply heat and perpendicular magnetism, the magnetic display type recycled sheet could obtain a black image.

<Comparative Example 2> Flake-like magnetic powder (major axis 30
A soft magnetic iron powder having a thickness of 1 μm and a thickness of 1 μm was subjected to a silane coupling treatment with trimethoxychlorosilane to hydrophobize the magnetic powder. Next, the flaky magnetic powder was sufficiently dispersed with dodecyl carboxylate (melting point 70 ° C.) under heating at 80 ° C. After that, it is emulsified in an aqueous solution of gum arabic and mixed with an aqueous solution of gelatin, heated to 40 ° C., acetic acid is added dropwise, the entire reaction system is cooled, formaldehyde is added dropwise to cure the wall material, and the flaky magnetic powder is added. A microcapsule having a size of 30 to 50 μm containing the dispersion medium was prepared, and microcapsulated display particles were produced. The microencapsulated display particles were dispersed in a urethane / isocyanate emulsion aqueous solution, coated on a synthetic paper having a thickness of 30 μm to a thickness of 80 μm, and dried at 50 ° C. for 1 hour to prepare a magnetic display type recycled sheet. . By heating this magnetic display type recycling sheet and applying horizontal magnetism, the surface of the magnetic display type recycling sheet exhibited a metallic luster color. When a magnetic head having a heating means was used to apply heat and perpendicular magnetism, the magnetic display type recycled sheet could obtain a black image.

<Comparative Example 3> Flake-shaped magnetic powder (major axis 10
A soft magnetic iron powder having a thickness of 1 μm and a thickness of 1 μm) was subjected to a silane coupling treatment with trimethoxychlorosilane to make the surface of the magnetic powder hydrophobic. Next, the flaky magnetic powder was sufficiently dispersed with liquid paraffin under heating at 40 ° C. After that, it is emulsified in an aqueous solution of gum arabic and mixed with an aqueous solution of gelatin, heated to 40 ° C., acetic acid is added dropwise, the entire reaction system is cooled, formaldehyde is added dropwise to cure the wall material, and the flaky magnetic powder is added. A microcapsule having a size of 50 to 80 μm and containing a dispersion medium was prepared, and microcapsulated display particles were produced. The microencapsulated display particles are dispersed in an epoxy / polyamide emulsion aqueous solution, and coated on polyethylene terephthalate (PET) having a thickness of 20 μm so as to have a thickness of 100 μm,
It was dried at 50 ° C. for 1 hour to prepare a magnetic display type recycled sheet. Heating this magnetic display type recycling sheet,
By applying horizontal magnetism, the surface of the magnetic display type recycling sheet showed a metallic luster color. When a magnetic head having a heating means was used to apply heat and perpendicular magnetism, the magnetic display type recycled sheet could obtain a black image.

Comparative Example 4 Flake-like magnetic powder (major axis 10
silane coupling treatment of a soft magnetic iron-nickel alloy having a thickness of 1 μm with trimethoxychlorosilane,
The surface of the magnetic powder was hydrophobized. Next, the flaky magnetic powder was sufficiently dispersed with liquid paraffin under heating at 40 ° C. After that, it is emulsified in an aqueous solution of gum arabic and mixed with an aqueous solution of gelatin, heated to 40 ° C., acetic acid is added dropwise, the entire reaction system is cooled, formaldehyde is added dropwise to cure the wall material, and the flaky magnetic powder is added. A microcapsule having a size of 170 to 200 μm and containing a dispersion medium was prepared, and microcapsulated display particles were produced. The microencapsulated display particles were dispersed in a urethane / isocyanate emulsion aqueous solution, and the thickness was 300 μm on polyethylene terephthalate (PET) having a thickness of 50 μm.
And was dried at 50 ° C. for 1 hour to prepare a magnetic display type recycled sheet. By heating this magnetic display type recycling sheet and applying horizontal magnetism, the surface of the magnetic display type recycling sheet exhibited a metallic luster color. Also,
When a magnetic head having a heating means was used to apply heat and perpendicular magnetism, the magnetic display type recycling sheet could obtain a black image.

<Comparative Example 5> Flake-shaped magnetic powder (major axis 10
silane coupling treatment of a soft magnetic iron-nickel alloy having a thickness of 1 μm with trimethoxychlorosilane,
The surface of the magnetic powder was hydrophobized. Next, the flaky magnetic powder was sufficiently dispersed with liquid paraffin under heating at 40 ° C. After that, it was emulsified in an acrylic resin emulsion aqueous solution, mixed with a gelatin aqueous solution, and heated to 40 ° C.,
Acetic acid was added dropwise, the whole reaction system was cooled, formaldehyde was added dropwise to cure the wall material, and microcapsules of 170 to 200 μm in size containing flake-like magnetic powder and dispersion medium were prepared. Generated display particles. The microencapsulated display particles are dispersed in an epoxy emulsion aqueous solution, coated on a polyethylene terephthalate (PET) having a thickness of 50 μm so as to have a thickness of 300 μm, and dried at 50 ° C. for 1 hour to obtain a magnetic display type recycled sheet. It was made. By heating this magnetic display type recycling sheet and applying horizontal magnetism, the surface of the magnetic display type recycling sheet exhibited a metallic luster color. When a magnetic head having a heating means was used to apply heat and perpendicular magnetism, the magnetic display type recycled sheet could obtain a black image.

<Test> Examples 1 and 2 and Comparative Example 1,
The magnetic display type recycled sheet prepared in Nos. 2, 3, 4 and 5 was used to form a predetermined image by applying heat and magnetism using a magnetic display device, and repeated printing and erasing resistance, image sharpness (recording area Occurrence of fogging, etc.), image stability (effect of external magnetic field), visibility and pressure resistance were tested and evaluated under the following conditions. Test conditions and evaluation (a) For repeated print erasure resistance, print erasure is 5
The process was repeated 0 times and the presence or absence of scratches on the surface of the recycled sheet was evaluated. (B) Regarding the sharpness of the image, the line width of the displayed image was measured, and when the line width was 20% or more thicker than the written line width, it was evaluated as bad, and when the line width was 20% or less, it was evaluated as good. (C) Regarding the image stability, a 1000 Gauss permanent magnet is brought into contact with the displayed image, and if the image is affected by the unreadable state due to the action of this magnetism, it is determined to be defective and the magnetic effect is readable. If not received, it was rated as good. (D) The visibility was measured by an optical densitometer and evaluated by the difference between the density of the base of the display and the density of the image.
When the density difference was 1.0 or more, the contrast was good and was evaluated as good, and when the density difference was 0.9 or less, it was evaluated as poor. (E) Regarding pressure resistance, 200 g / cm on the displayed image
^When the image is legible when ² pressure is applied,
When it was unreadable, it was evaluated as bad. The evaluation results are shown in Table 1.

[0030]

[Table 1]

As shown in Table 1, by reducing the size of the microencapsulated display particles, the particles of Examples 1 and 2 were obtained.
Image was clear and high resolution was obtained. Comparative Examples 4 and 5
Since the recycled sheet of No. 1 has large microencapsulated display particles, it lacked in image clarity. In addition, Comparative Examples 3 and 4
The recycled sheets of Nos. 5 and 5 had fog in the non-recording area. Further, a difference in pressure resistance appeared due to the characteristics of the binder, and the recycled sheets of Comparative Examples 1 and 5 were thermoplastic resins and thus lacked in pressure resistance. Next, when an external magnetic field was applied after image formation, Examples 1 and 2 and Comparative Examples 1 and 2
However, the images of Comparative Examples 3, 4 and 5 were disturbed and the image stability was insufficient.

[0032]

The magnetic display type recycling sheet of the present invention is a magnetic display layer in which microencapsulated particles composed of a dispersion medium in which flaky magnetic powder is dispersed and which is in a solid phase state at room temperature are dispersed in a binder. In the non-recorded state, the flaky magnetic powder is oriented horizontally with respect to the surface of the magnetic display type recycled sheet, and the surface of the magnetic display type recycled sheet shows a uniform color tone of metallic luster. From the surface side of the display type recycling sheet, scanning is performed with a thermal / magnetic head device having a heating means, and the flake-shaped magnetic powder is oriented vertically by the application of heat and perpendicular magnetism, and a black image is formed by the flake-shaped magnetic powder. It Also, erase
By heating the entire surface and applying horizontal magnetism, or by scanning the surface with a magnetism generating means having a heating means, the flaky magnetic powder is oriented along the horizontal magnetism, and the surface of the visible display part is The color tone becomes uniform with metallic luster again, and the image is erased. That is, the magnetic display type recycle sheet of the present invention is clearly bright and dark so that the part to which heat and magnetism are applied is clearly different from the part to which no heat is applied, and the visibility, resolution, image stability and durability are improved. It has an excellent effect on Further, according to the present invention, since image formation can be easily carried out by heating at a low temperature and applying magnetism, the energy consumption is low, and the microencapsulated display particles containing magnetic powder or the like dispersedly arranged in the recording layer. The resolution can be increased by controlling the particle size of the. Furthermore, since heat and magnetism can be applied in a non-contact manner, it has excellent repeatability.
Further, since the dispersion medium in which the flake-like magnetic powder is dispersedly arranged shows a solid state at room temperature and is fixed except during recording, even if magnetism such as a magnet is externally applied after information recording, the flake-like magnetic property is Orientation of powder does not occur, stable recording is obtained, and image stability is excellent. Furthermore, the magnetic display layer can be thinned by controlling the particle size of the microencapsulated display particles and the type of binder, and can be used as a paper-like information recording sheet instead of the information recording paper. Such a magnetic display type recycling sheet can be reused, for example, as facsimile paper, recording paper for various measuring instruments, printing paper for word processors, etc., and can be reused repeatedly to reduce paper dust from the office and save resources. Is also useful. Further, by mixing the microencapsulated display particles in which the flake-like magnetic powder is dispersed in the binder, it is possible to easily form a coating liquid, and the manufacturing process of the magnetic display type recycled sheet can be simplified.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a cross section showing an embodiment of a magnetic display type recycling sheet of the present invention.

FIG. 2 is an explanatory view in cross section showing a state at the time of manufacturing the magnetic display type recycled sheet of the present invention.

FIG. 3 is an explanatory view showing a cross section showing an unrecorded state by an erasing operation of the magnetic display type recycling sheet of the present invention.

FIG. 4 is an explanatory view in cross section showing a state of the magnetic display type recycling sheet of the present invention during recording.

[Explanation of symbols]

 10 ... Magnetic display type recycling sheet 11 ... Support 12 ... Magnetic display layer 13 ... Micro-encapsulated display particles 14 ... Binder 15 ... Flake magnetic powder 16 ... Dispersion medium

Claims (5)

[Claims] 1. A magnetic display type recording medium which can be repeatedly printed and erased by providing a magnetic display layer made of a rewritable rewritable material, wherein the magnetic display layer is at least flakes on a support made of a non-magnetic material. A magnetic display type recycle sheet, characterized in that microencapsulated display particles containing a magnetic powder and a dispersion medium that is in a solid state at room temperature and is dispersed in a binder. 2. The flaky magnetic powder has an average major axis of 10 to 10.
The magnetic display type recycling sheet according to claim 1, wherein the magnetic display type recycling sheet has a thickness of 20 μm, a thickness of 0.1 to 2 μm, and a coercive force of 1000 Oe or less. 3. The magnetic display type recycle sheet according to claim 1, wherein the support is made of an opaque non-magnetic material and has a thickness in the range of 10 to 100 μm. 4. The magnetic display type recycling sheet according to claim 1, wherein the dispersion medium is made of an organic compound having a melting point of 35 ° C. or higher and 80 ° C. or lower. 5. The magnetic display type recycling sheet according to claim 1, wherein the binder is made of a thermosetting resin.