JPH09160511A - Magnetic recording medium and its recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recording medium capable of displaying an image of high resolution and visibility and excellent stability and displaying a reversible and multicolor display by permitting magnetically impressed and unimpressed portions to be different in brightness. SOLUTION: This magnetic recording medium comprises the laminate of a pattern forming layer 12, which consists of patterns with yellow (Y), magenta (M), cyan (C), and black (B), and a magnetic storage layer 13, which comprises microcapsules 15 distributed within a binder 16, each of the microcapsules 15 enclosing at least flaked magnetic particles and a dispersion medium formed by the dispersion of the particles and showing a solid-phase state at room temperature. For every pattern consisting of a color corresponding to the color of picture elements forming as image, the microcapsules 15 in the magnetic storage layer 13 are heated to melt the dispersion medium, and the flaked magnetic particles are oriented by application of magnetism in the horizontal or vertical direction, thereby forming a full-color image corresponding to each of the colors of the pattern forming layer 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording medium capable of displaying and erasing a pattern such as an image by applying magnetism with heating and a recording method therefor, and in particular, color display is possible, and resolution and image The present invention relates to a reversible display magnetic recording body having excellent stability and a recording method thereof.

[0002]

2. Description of the Related Art Conventionally, as a magnetic recording medium utilizing magnetism, a magnetic field is applied to a suspension in which magnetic particles are dispersed in a coloring dispersion medium, as described in, for example, JP-A-48-56393. By doing so, a method is known in which the magnetic particles are moved to change the color of the colored dispersion medium and display is performed.

However, in such a magnetic recording medium, when the suspension is sealed between two substrates and one of the substrates draws characters and patterns with a magnetic pen to apply magnetism, the magnetic particles of the suspension are attracted. Although the characters and patterns are obtained as they are, since the specific gravity of the magnetic particles is much larger than that of the dispersion medium, the attracted magnetic particles have the drawback that the characters and patterns cannot be retained for a long time because they settle with time. .

Further, since all the magnetic particles magnetized by the magnetic pen are attracted to the magnetic pen, the magnetic particles existing apart from the magnetic pen are also attracted, so that only unclear characters and patterns are obtained. It also had drawbacks. In order to prevent sedimentation of magnetic particles, for example, if the magnetic particles are made finer or the magnetic particles are coated with a polymer having a low specific gravity, and the apparent specific gravity of the magnetic particles approximates that of the dispersion medium, the magnetic particles Since the force becomes extremely small, it becomes difficult to be sucked by the magnetic pen, which causes a defect that it is not possible to obtain a clear character or pattern with high density.

Further, if the apparent specific gravity of the magnetic particles is approximated to that of the dispersion medium, the magnetic particles are difficult to be attracted to the opposite side of the substrate even when characters and patterns are erased, and the particles cannot be completely erased. Repeatedly, it turned black overall, which was not practical.

As a mode for solving these drawbacks, for example, Japanese Patent Publication No. 57-27463 and Japanese Patent Laid-Open No. 62-53.
As described in Japanese Patent No. 359, as a dispersion medium,
By using a liquid that has a yield value of a certain value or more, or by using a thickener, clear and high-contrast characters and images without blur can be displayed, and the display can be kept stable for a long time, and erasure can be completed completely. There are known magnetic recording media that can be neatly cleaned.

However, this magnetic recording medium is formed by forming honeycomb cells each having a side and a depth of about 2 mm on the entire surface of a transparent plastic sheet, and the magnetic particles and the white pigment are contained in the cells. The suspension was injected into a dispersion medium, and the suspension was sealed with a transparent sheet, which had the following drawbacks. That is, since the image is formed by moving the magnetic particles from the back surface to the front surface in the honeycomb-shaped cell, it is impossible to make the resolution of the image smaller than that of the honeycomb-shaped cell. Further, it is difficult to form honeycomb cells, to make the honeycomb cells large or very small, and to inject a suspension into the honeycomb cells.

As another mode, for example, Japanese Patent Laid-Open No. 2-14
As described in JP-A No. 6082 and JP-A-4-233581, unlike a magnetic recording medium in which magnetic particles and a pigment are sealed in a honeycomb cell as described above, magnetic particles are encapsulated in microcapsules. A magnetic recording medium is known in which this is coated on a support. According to this method, the resolution can be increased by controlling the particle size of the microcapsules, and the manufacturing process is easy. Further, various films and the like can be selected as the substrate on which the microcapsules are applied, and the shape and size can be freely selected.

However, the image formation shown here is performed by the following method. First, the permanent magnet attracts the light-absorbing magnetic particles in the microcapsule to the back surface side of the magnetic recording medium, and the light-reflecting non-magnetic particles remain on the surface of the magnetic recording medium. It becomes the color of non-magnetic particles and is in an erased state. Then, by applying and recording magnetism from the surface of the magnetic recording medium by a permanent magnet, the light-absorbing magnetic particles are magnetically attracted to the surface, and desired characters and images are formed. Therefore, in such image formation, it takes a long time to attract the magnetic particles, resulting in a magnetic recording material having poor sensitivity.

Further, as another embodiment utilizing the microcapsules, for example, JP-A-1145637, JP-A-63-153197, JP-B-4-7518, JP-A-6-79986 and JP-A-6-79986. 6-9206
No. 8, or Eyne S. Trumble
P. S. & E. 7 213 (1963), there is known a magnetic recording medium in which light-absorbing magnetic particles and light-reflecting non-magnetic particles are encapsulated in microcapsules.

In the image forming method of this embodiment, first, when the magnetic recording medium is manufactured, the magnetic particles in the coated capsules are orientated in advance in parallel with the plane of the magnetic recording medium so that all the incident light is reflected to make it appear bright. Next, magnetic recording causes magnetic particles to rotate and scatter incident light.
It becomes absorbed, and contrast is generated, and a black image is formed.

However, the magnetic recording material 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. Furthermore, since the magnetic recording medium can be easily printed and erased by magnetic force, the image may be fogged in the unprinted portion or the image may be erased by just touching the magnet. It has the drawback of poor stability.

Further, as a magnetic recording medium capable of color display, for example, the N and S poles of the magnetic particles described in JP-A-1-63991 are colored in different colors, and the magnetic particles are rotated by applying a magnetic force. A magnetic recording body for color display, and magnetic particles having different magnetic properties described in JP-A-4-175196 are colored in different colors,
2. Description of the Related Art There is known a magnetic recording body that controls a magnetic field strength to perform color display.

In the former case, however, the magnetic recording medium for color display is manufactured by spraying a coloring dye solution on fine magnetic particles to color the magnetic recording particles. For example, the N and S poles of the magnetic particles have different colors. It is difficult to color fine magnetic particles when colored in the background, and the color coding of each pole is incomplete. In the latter case, it is difficult to control the magnetic field strength at the time of display, and there is ambiguity in controlling the magnetic field. However, both of them have a drawback that clear color display cannot be performed, and since only one color is color-displayed, multi-color display cannot be performed.

[0015]

As described above, it is difficult to display a high-resolution image in the conventional magnetic recording body using the magnetic body as the display means, and the image displayed due to the influence of external magnetism. The problem that images cannot be stably recorded due to partial or unreadable state of images or fogging of unprinted parts, and clear color display is difficult and multicolor display is impossible There is no magnetic recording medium which has the mobility of the magnetic particles contained therein, that is, has both good reactivity in recording and stability of recorded image. Therefore, the present invention provides a reversible and multicolor color displayable magnetic recording medium which shows different contrast between a magnetically applied portion and a non-applied portion, has a high resolution, is clear, and has excellent image stability. The purpose is to provide.

[0016]

The present invention has been made to achieve the above object, and the invention according to claim 1 provides a yellow (Y) layer on a support made of a non-magnetic material.
A pattern forming layer having a pattern in which each color of magenta (M), cyan (C), and black (Bk) is arranged; at least flake-shaped magnetic particles and a dispersion medium which is in a solid state at room temperature and is formed by dispersing the magnetic particles. And a magnetic recording layer in which microcapsules encapsulating are dispersed and arranged in a binder.

According to a second aspect of the present invention, in a binder, microcapsules containing at least flake-shaped magnetic particles and a dispersion medium that is in a solid state at room temperature and is dispersed in a binder are formed on a support made of a non-magnetic material. And a magnetic recording layer dispersedly arranged on the magnetic recording layer and a pattern forming layer having a pattern in which colors of yellow (Y), magenta (M), cyan (C), and black (Bk) are arranged. And a magnetic recording medium.

The invention of claim 3 is claim 1 or claim 2.
In the magnetic recording material described in [1], the pattern is yellow (Y), magenta (M), cyan (C), black (B
It is characterized by arranging patterns formed by forming each color of k) as one unit.

According to a fourth aspect of the present invention, there is provided the first or second aspect.
In the magnetic recording material according to the item 1, the melting point of the dispersion medium is 35 ° C.
It is characterized by being an organic compound in the range of 100 ° C. or lower.

The invention of claim 5 is claim 1 or claim 2.
In the magnetic recording material described in the item [1], the average particle diameter of the microcapsules is between 10 μm and 1000 μm.

The invention of claim 6 is claim 1 or claim 2.
In the magnetic recording material described in (1), the flaky magnetic particles have an average major axis of 5 μm to 30 μm and an average thickness of 0.1 μm to 5 μm.

The invention of claim 7 is claim 1 or claim 2.
The magnetic recording medium described in the above item 1 is characterized in that a protective layer is formed on the magnetic recording layer.

According to an eighth aspect of the invention, a support made of a non-magnetic material and a pattern forming layer on which a pattern of each color of yellow (Y), magenta (M), cyan (C) and black (Bk) is formed, A recording method of a magnetic recording body having a magnetic recording layer, wherein microcapsules containing flake-shaped magnetic particles and a dispersion medium that is in a solid state at room temperature and is dispersed in a binder are disposed. For the magnetic recording layer obtained by orienting the flaky magnetic particles in the microcapsules in the entire region in the horizontal or vertical direction,
Visible information is recorded by partially heating and melting the dispersion medium of the magnetic recording layer in each pattern unit of each color forming the pattern forming layer and applying magnetic force vertically or horizontally to orient the flaky magnetic particles in different directions. This is a method for recording on a magnetic recording medium, which is characterized by being performed.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. 1 is a plan view showing an embodiment of the magnetic recording medium of the first invention, FIG. 2 is a sectional view taken along line XX of FIG. 1, and FIG. 3 is a magnetic recording medium of the second invention. FIG. 4 is a plan view showing an embodiment, FIG. 4 is a sectional view taken along line YY of FIG. 3, and FIG. 5 shows an embodiment of microcapsules used in the magnetic recording layer of the magnetic recording body of the present invention. 7 is a sectional view, FIG. 6 is an enlarged plan view obtained by partially enlarging the arrangement pattern of the pattern forming layer of the magnetic recording medium of the present invention, and FIG.
FIG. 8 is a sectional view showing the unrecorded state of the magnetic recording body of the present invention, and FIG. 8 is a sectional view of the magnetic recording body of the present invention during recording.

FIG. 1 is a plan view of a magnetic recording body 1 according to the first aspect of the present invention, and a pattern observed on an upper surface thereof by an image formed by the pattern forming layer 12 and the magnetic recording layer 13. There is an image A. FIG. 2 shows a cross-sectional structure of the magnetic recording medium 1, which includes a support 11 and a pattern forming layer 12 having a pattern in which colors of yellow (Y), magenta (M), cyan (C), and black (Bk) are arranged. The binder 1 is a microcapsule 15 containing flaky magnetic particles and the like.
Magnetic recording layer 13 to which the coating material dispersed in 6 is applied,
The protective layer 14 is sequentially stacked. The magnetic recording layer 1
In No. 3, a large number of microcapsules containing flake-shaped magnetic particles and a dispersion medium that is in a solid state at room temperature and are dispersed and arranged randomly in the magnetic recording layer 13. Although the microcapsules and the microcapsules arranged according to the pattern of the pattern forming layer 12 are described here for the sake of description, the microcapsules that are actually fine particles are randomly arranged and the size of each pattern is large. Since there is no limitation, one microcapsule 15 is not necessarily arranged for each one of the patterns of the pattern forming layer 12.

FIG. 7 is a plan view of the magnetic recording medium 2 according to the second aspect of the present invention. On the upper surface of the magnetic recording medium 2, an image of the magnetic recording layer 12 is observed through the pattern forming layer 13 to form a pattern image. B. FIG. 8 shows a cross-sectional structure of the magnetic recording body 2. The magnetic recording layer 13 is coated with a coating material in which a support 11 and microcapsules 15 containing flaky magnetic particles are dispersed in a binder 16, a yellow (Y ), Magenta (M), cyan (C), and black (Bk). The pattern forming layer 12 and the protective layer 14 are sequentially stacked. As described above, the microcapsules and the pattern forming layer 12 are described here for the sake of explanation.
Although it is described as arranged according to the pattern of
Actually, the microcapsules, which are fine particles, are randomly arranged, and the size of each pattern is not limited. Therefore, one microcapsule 15 is necessarily arranged for each pattern of the pattern forming layer 12. Not a thing.

FIG. 5 is a sectional view showing an embodiment of the microcapsules 15 used in the magnetic recording layer 13 of the magnetic recording bodies 1 and 2 of the present invention. The microcapsule 15 includes a flake-shaped magnetic particle 22, a core substance 21 mainly composed of suspension dispersed in a dispersion medium (eg, an organic compound such as wax) 23 that is in a solid state at room temperature, and a shell made of a polymer or the like. It is a structure in which the substance 24 is encapsulated.

The flaky magnetic particles 22 are made of, for example, iron, nickel, iron / nickel, stainless steel such as iron / nickel / chromium, fine particles of cobalt, cobalt / aluminum, samarium / cobalt alloy, or the like by an atomizer or a hammer mill. Flakes can be used. In particular, in order to enhance the affinity of the magnetic particles with an organic solvent or the like, it is preferable to carry out a higher ester treatment, a silane coupling treatment, a titanate coupling treatment or the like. The size of the flake-shaped magnetic particles 22 in the present invention is 5 μm to 30 μm and has a thickness of 0. 1 in consideration of easiness of rotation in a microcapsule due to application of magnetism and image contrast of the magnetic recording layer 13. 1 μm to 3
It is preferably between μm.

The dispersion medium 23 is at room temperature (about 10-35).
It should be solid (in the range of ° C) (in a solid state) and be in a fluid state when heated to a temperature higher than room temperature (in the range of approximately 40 to 100 ° C), such as an organic compound. Naturally known or synthetic waxes such as paraffin wax and carnauba wax, naturally occurring or synthetic resins, carboxylic acid esters and the like which are generally known and satisfy the above conditions can be used alone or in combination.

The core substance 21 containing the above-mentioned flaky magnetic particles 22, the dispersion medium 23 and the like as main components is covered with a shell substance 24 such as a polymer to be microencapsulated. This shell substance 2
Examples of the resin used as 4 include commonly used resins such as acrylic resin, methacrylic resin, polystyrene, polyester resin, polyurethane resin, polyurea resin, polyamide resin, epoxy resin, and natural resin. It is also possible to use them alone or in combination of two or more.

Microcapsules 1 having the above shell material
The method for producing 5 includes a phase separation method in which a concentrated phase of the polymer is separated around the core substance dispersed in the polymer solution, and a liquid for curing the polymer around the core substance in the polymer solution with a curing test agent for the polymer or the like. Medium-cure coating method, in-situ polymerization method in which the surface of the core material is covered with a polymer by supplying a monomer or a polymerization catalyst from either one of the emulsion in which the core material is dispersed, or the external phase, and the emulsion in which the core material is dispersed. A microencapsulation technique such as an interfacial polymerization method in which a monomer is supplied from both the internal phase and the external phase is suitable, but the method is not limited to these methods.

In particular, the flake-shaped magnetic particles 22 as the core substance 21 are uniformly dispersed in the dispersion medium 23, and the particles are produced by the in-situ polymerization method in which the monomer is supplied from the outer phase of the suspension, or the phase separation method. It is possible to manufacture the microcapsules 15 having uniform diameters and in which the flake-shaped magnetic particles 22 can be easily moved. The polymerizable monomer used here is preferably acrylic acid ester, methacrylic acid ester, styrene and its derivatives, isocyanate, various amines, compounds having an epoxy group, and the like.

Next, FIG. 6 is a partially enlarged plan view of an arrayed pattern of the pattern forming layer 12 provided in the magnetic recording bodies 1 and 2 of the present invention. (A) Yellow (Y) / magenta (M) A pattern forming layer 12 formed by arranging a pattern in which each color of cyan (C) and black (Bk) is formed in a square shape, and repeating this array in the vertical and horizontal directions, respectively.
a, (b) Yellow (Y) and magenta (M) in the shape of a field
Pattern formation layers 12b, (c) yellow (Y), magenta (M), which are formed by arranging patterns in which cyan (C) and black (Bk) colors are respectively formed and sequentially repeating this arrangement in the vertical and horizontal directions. There is a pattern forming layer 12c formed by sequentially arranging patterns in which each color of cyan (C) and black (Bk) is formed in a row. As the base of the pattern forming layer 12, for example, polyvinyl chloride resin, polyester resin, polymethyl methacrylate resin, polystyrene resin, synthetic resin such as polyethylene terephthalate, natural resin, synthetic paper having a flat surface should be used. Which is dyed or colored in each color of yellow (Y), magenta (M), cyan (C), and black (Bk). Specifically, yellow (Y) is an azo type, Anthraquinone-based dyes,
Azo lake-based, quinacridone-based organic pigments, or yellow lead-like inorganic pigments as magenta (M), azo-based, condensed methine-based dyes, azo lake-based, anthraquinone-based organic pigments, and cyan (C) Benzodifuranone-based dyes, phthalocyanine-based, thioindico-based organic pigments and the like can be used. The pattern forming layer 12 is formed with a pattern of each color of yellow (Y), magenta (M), cyan (C), and black (Bk), and a multicolor image can be visually recognized by a combination of these colors.

Recording on the further laminated magnetic recording layer 13, that is, the movement (orientation) of the flake-shaped magnetic particles 22 in the microcapsules by heating and magnetic application controls the light transmission amount of the magnetic recording layer 13 (brightness and contrast of contrast). Image is formed, and heating / magnetic is performed for each pattern of each color of yellow (Y), magenta (M), cyan (C), and black (Bk) corresponding to the constituent pixels of the image to be recorded. By providing a mark or the like that serves as a reference point for determining the position when applying the voltage, accurate position control for image recording becomes possible. For example, the pattern formation layer 1
In the case of 2a, the arrangement consisting of patterns of each color of yellow (Y), magenta (M), cyan (C), and black (Bk) is arranged as one unit in the vertical and horizontal directions,
A mark 17 serving as a reference point is provided at the start point of each line of the vertical direction and / or the horizontal direction (and also at the end point if necessary) by using one pattern for the vertical direction and the horizontal direction as one line, A position detection control means (not shown) that recognizes the mark 17 by an optically detectable sensor and detects the position is used to control the movement of the heating / magnetism applying means to a predetermined position. In this case, the heating / magnetism applying means is moved to a position serving as a start point, and the heating / magnetism applying means sequentially moves in the vertical and horizontal directions line by line, and the pattern on the line corresponding to each pixel of the recorded image. To heat and apply magnetism. By adopting a mechanism that sequentially moves for each line, it is possible to perform highly accurate recording by only detecting the positions of the start point, the start point and the end point of the line.

Next, the magnetic recording medium 1 of the first invention of the present invention
As shown in FIG. 2, the pattern forming layer 12 having the above-mentioned constitution is formed on the support 11, and the microcapsules 15 having the above-mentioned constitution are applied together with the binder 16 to form the magnetic recording layer 13 and further protected. It is made by laminating layers 14. In the magnetic recording medium 2 of the second invention of the present invention, as shown in FIG. 8, the microcapsules 15 having the above-mentioned structure are coated on the support 11 together with the binder 16 to form the magnetic recording layer 13, and It is produced by forming the pattern forming layer 12 having the above structure and further laminating the protective layer 14.

The support 11 is a synthetic resin such as polyvinyl chloride, polyester, polycarbonate, polymethylmethacrylate, polystyrene, polyethylene terephthalate, natural resin, paper, synthetic paper, metal, ceramics, etc., alone or in combination. Can be used. Further, its shape can be selected in accordance with the application such as a card shape or a sheet shape, a film shape, and further physical properties required according to the application, for example, light reflectivity, strength, rigidity, concealability,
It can be appropriately selected from the above materials in consideration of light opacity and the like.

As the binder 16 in which the microcapsules 15 are dispersed, a water-based binder, a solvent-based binder, an emulsion-based binder or the like is appropriately used.
Further, as the protective layer 14, an epoxy resin, tetrafluoroethylene or the like, or a synthetic resin such as polyvinyl chloride, polyester, polycarbonate, polymethylmethacrylate, polystyrene or polyethylene terephthalate,
Natural resin or the like can be used. The protective layer 14 needs to hold the microcapsules 15 formed on the support 11 and have a light-transmitting property so that the flaky magnetic particles 22 in the microcapsules 15 can be seen from the outside. Any material can be used as long as it satisfies necessary conditions such as strength.

The magnetic recording layer 13 and the protective layer 14 are formed by a known printing method such as offset printing, gravure printing, silk screen printing, or roll coating or knife edge coating. Method, a transfer method using a transfer sheet having a transfer layer containing the microcapsules 15 described above, an ink jet method in which ink containing a plurality of types of microcapsules 15 according to the colorant described above is sprayed on a substrate, and a support 11 It can be formed by a forming method such as a method of filling a solution in which the above-mentioned microcapsule 15 is mixed between the protective layer 14 and the protective layer 14, and can be appropriately selected from the above methods according to the use and quantity of the information recording medium to be produced. can do. In addition, the pattern forming layer 1
2 can be formed by a dyeing method, a printing method, or the like in which a support is colored with a binder containing a dye or a pigment,
The method can be appropriately selected from the above methods according to the use and quantity of the information recording medium to be manufactured.

Next, a method of forming a display image on the magnetic recording medium of the present invention will be described. The magnetic recording medium 1 of the first invention shown in FIG. 2 will be described and the case of the magnetic recording medium 2 of the second invention will be omitted, but the recording operation is the same. FIG.
Is formed by laminating a sheet-shaped pattern forming layer 12 on a support 11, and further applying microcapsules 15 containing a suspension in which the flake-shaped magnetic particles 22 shown in FIG. 5 are dispersed in an organic solvent as a dispersion medium 23. FIG. 3 is a sectional view of a magnetic recording body 1 of the present invention which is At the beginning of manufacture, the flake-shaped magnetic particles 22 are fixed in the dispersion medium 23 in a state of being uniformly dispersed in the microcapsules 15.

FIG. 3 generally shows a state in which an image is not recorded, that is, a state in which the image is erased or unrecorded, and the microcapsule 15 is horizontal to the magnetic recording layer 13.
It is explanatory drawing which shows the state formed by orienting the flake-shaped magnetic particle 22 inside. In this case, when the magnetic recording layer 13 is heated at a temperature slightly higher than the melting point of the dispersion medium 23 by the heat / magnetic recording head 30 which is a heating / magnetic applying means, the dispersion medium 23 in all the microcapsules is melted. Becomes
The flaky magnetic particles 22 can be oriented or moved (rotated). Then, by applying magnetism, the orientation state becomes the same as the direction of magnetism application. Therefore, in the figure, the magnetic recording layer 13 is heated uniformly and the magnetic field applied in the horizontal direction causes the flaky magnetic particles 2 in the microcapsules 15 to be dispersed.
2 is oriented horizontally in the magnetic recording layer 13. This allows
On the surface of the magnetic recording medium, incident light is mostly reflected by the flake-shaped magnetic particles 22 as a non-image portion, and the lower pattern forming layer 12 is hidden.

FIG. 4 is a sectional view of the magnetic recording medium 1 of the present invention during recording. The thermal / magnetic recording head is aligned with the mark 17 serving as a reference point by using the position detection control means (not shown) described above. Magnetic recording layer 13 of magnetic recording body 1 according to 30
On the other hand, at a temperature slightly higher than the melting point of the dispersion medium 23, the recorded image is color-separated into each color of yellow (Y), magenta (M), cyan (C), and black (Bk). The magnetic recording layer 13 is partially heated, the dispersion medium 23 in the heated microcapsules 15 is brought into a molten state, and the flake-shaped magnetic particles 22 become movable (rotatable). It is the same as the direction of magnetic application. Therefore, in the figure, the dispersion medium 23 is heated to a molten state, and the microcapsules 15 of the magnetic recording layer 13 are heated.
The horizontally oriented flaky magnetic particles 22 in the
The magnetic field applied in the vertical direction causes the magnetic recording layer 13 to be oriented in the vertical direction, so that the incident light is reflected by the surface of the support 11 without being reflected by the flake-shaped magnetic particles 22 as an image portion, and the pattern is formed. The color of the yellow pattern portion of the forming layer 13 is observed from above the magnetic recording body 1.
Therefore, the image to be recorded is separated into each color of yellow (Y), magenta (M), cyan (C), and black (Bk), and the thermal / magnetic recording head 30 is sequentially or simultaneously formed according to the pixels of each color. After moving to a predetermined position, an image is formed by heating and magnetic application, and a multicolor color image is created by the pixels of each color.

The image to be recorded may be color-separated in advance, or may be color-separated while scanning an original or the like during recording and simultaneously recorded on the magnetic recording medium. The thermal / magnetic head 30 used for recording the magnetic recording medium 1 of the present invention is, for example, a method in which heat is applied only to the recording portion after forming a uniform magnetic field over the entire area, and recording is performed uniformly over the entire area. There is a method of recording by applying a magnetic field only to the recording portion after applying the magnetic field. (1) Specifically, an optical head capable of thermal conversion such as laser light and magnetic field formation capable of applying a uniform magnetic field. Means, (2) a magnetic field forming means capable of applying a uniform magnetic field to the thermal head, and (3) a heat applying means capable of applying uniform heat to the magnetic head, and also scans the heat and the magnetic field linearly. The configuration may be selected, and can be appropriately selected depending on the application. In particular, the heating means for applying heat may have a heating capacity for melting the above-mentioned dispersion medium 23 such as wax or organic compound.

By the way, in the case of the magnetic recording medium 2 of the second invention shown in FIG. 8, the magnetic particles 2 in the microcapsules 15 are used.
2 The surface is made to absorb or scatter light, and the support 11 is made to reflect light. Conversely, the magnetic particles 22 in the microcapsules 15 are made to reflect light, and the support 11 is made of a black-based material. In some cases, for example, in the non-image area, the flake-shaped magnetic particles 22 in the microcapsules 15 are oriented in the horizontal direction so that the light is absorbed or scattered. The image part where a certain dark color is recorded while the image is recorded is the microcapsule 1
5 orients the flaky magnetic particles 22 in the vertical direction,
By making the reflected light of the irradiation light from the support visible through the pattern of the pattern forming layer 12, it is possible to recognize the image from the contrast due to the brightness. In the latter, for example, in the non-image area, the flake-shaped magnetic particles 22 in the microcapsules 15 are vertically oriented, whereby the irradiation light is in a dark color in a state of being absorbed or scattered by the support, while an image is recorded. In the image portion, the flake-shaped magnetic particles 22 in the microcapsules 15 are oriented in the horizontal direction, and the reflected light from the flaked magnetic particles 22 in the horizontal direction of the irradiation light is visually observed through the pattern of the pattern forming layer 12. By setting the light color state, the image can be recognized from the contrast due to the brightness. It should be noted that both of them may have a positive / negative relationship in which the states of the image portion and the non-image portion are reversed, and in this case, the lightness and darkness described above are reversed.

Since these image formations are simple due to heat with low energy to the extent that magnetism and the viscosity of the dispersion medium are lowered, recording is easy, and the resolution can be improved by controlling the particle size of the microcapsules. Higher image formation is possible. In addition, the image formed by the thermal / magnetic head is in a fixed state at the same time when the dispersion medium returns to room temperature, so that the recording stability is good, and since the image formation only by magnetism cannot be performed except in the melted state, No fogging caused by touching the magnet. The magnetic recording medium according to the present invention has the mobility (rotation) of the contained flake-like colored magnetic particles during recording, that is, both good recording reactivity and stable recorded image.

Furthermore, since the microcapsules can be made into a coating liquid by mixing with a binder, they can be applied to various supports and can be processed into various shapes, and the manufacturing process is simple. Therefore, the range of applications can be expanded.

The image recorded on the magnetic recording medium of the present invention is various visible information such as letters, numbers, marks, patterns, pictures, photographs, etc., and the pattern is formed by transmitting incident light through the magnetic recording layer and reflecting on the surface of the support. An image composed of colors through the forming layer 12,
The recorded image can be visually recognized by the contrast with the color of the flaky magnetic particles oriented in the horizontal direction, and a clear multicolor image can be obtained. The entire surface of the magnetic recording layer can be completely or partially erased by heating the entire surface of the magnetic recording layer with a heat / magnetic recording head at a temperature slightly higher than the melting point of the dispersion medium and applying magnetic force in the vertical direction. Reversible recording and erasing can be repeated.

[0047]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to specific embodiments. <Example 1> 30 parts by weight of silane coupling-treated flake-shaped nickel powder was uniformly dispersed in 80 parts by weight of paraffin wax having a melting point of 80 ° C which was heated to 80 ° C and melted. Using 200 parts by weight of 10% aqueous gelatin solution heated to 1, a homogenizer was used to obtain an average particle size of about 5 μm at a rotation speed of 2000 rpm.
Dispersed for minutes. 200 parts by weight of a 10% aqueous solution of gum arabic was mixed with the obtained dispersion liquid, 1000 parts by weight of water was further added, the temperature was kept at 40 ° C., and a 10% aqueous solution of acetic acid was added dropwise.
The pH was adjusted to 4. After that, the liquid temperature was cooled to 7 ° C. and 3
10 parts by weight of 0% formalin aqueous solution was added, and 10% aqueous sodium hydroxide solution was added dropwise to adjust the pH to 9 to prepare gelatin-arabic gum wall microcapsules.

Next, a pattern corresponding to each color of yellow (Y), magenta (M), cyan (C), and black (Bk) is printed on a white polyethylene terephthalate (PET) film by a printing method (yellow (Y ) ・ Magenta (M) ・ Cyan (C) ・ Black (B
A pattern forming layer is formed by printing 4 colors in the order of k), and a coating liquid in which the above-obtained microcapsules are evenly dispersed in a polyvinyl alcohol aqueous solution is applied to provide a magnetic recording layer, which is further made of an acrylic resin. A protective film was laminated to obtain a magnetic recording material of the present invention.

The entire surface of this magnetic recording medium is heated to 90 ° C.,
A horizontal magnetic field was applied to the magnetic recording layer from the outside to orient the flaky magnetic particles in the microcapsules to be horizontal with respect to the surface of the magnetic recording layer, thereby leaving the magnetic recording layer in an unrecorded state. Next, the entire surface of the magnetic recording layer or a portion thereof is heated to 90 ° C. according to the image information to be recorded, and a magnetic field is applied in the perpendicular direction of the magnetic recording layer so that the flaky magnetic particles become perpendicular to the magnetic recording layer. Then, the image was recorded.

By the above operation, it is possible to form a bright and clear image of multicolor full color.

Example 2 A coating solution prepared by uniformly dispersing the same microcapsules as in Example 1 in an aqueous solution of polyvinyl alcohol was coated on a black polyethylene terephthalate (PET) film to form a magnetic recording layer, and a yellow ( Y), magenta (M), cyan (C), black (B
The pattern corresponding to each color of k) is printed by a printing method (four colors of yellow (Y), magenta (M), cyan (C), and black (Bk) are sequentially printed by offset printing) to form a pattern forming layer, which is formed from an acrylic resin. The following protective film was laminated to obtain a magnetic recording body of the present invention.

The entire surface of this magnetic recording medium was heated to 90 ° C.,
A magnetic field perpendicular to the magnetic recording layer was applied from the outside to orient the flake-shaped magnetic particles in the microcapsules so as to be perpendicular to the surface of the magnetic recording layer, thereby leaving the magnetic recording layer in an unrecorded state. Next, the entire surface of the magnetic recording layer or a part thereof is heated to 90 ° C. according to the image information to be recorded, and a magnetic field is applied in the horizontal direction of the magnetic recording layer so that the flake-shaped magnetic particles become horizontal to the magnetic recording layer. Then, the image was recorded. Although not shown, the magnetic recording medium of the present invention can be fitted to the concave portion of another substrate so that it can be seen from the outside, and can be used for another information recording medium as a display means including the magnetic recording portion. is there.

[0053]

According to the magnetic recording medium and the recording method of the magnetic recording medium of the present invention, a pattern formed by arranging each color of yellow (Y), magenta (M), cyan (C) and black (Bk) A forming layer, a magnetic recording layer in which microcapsules containing flake-shaped magnetic particles and a dispersion medium in which the flaky magnetic particles are dispersed and exhibit a solid state at room temperature are dispersed and arranged in a binder are provided. For each pattern consisting of each color according to the color, the flaky magnetic particles of these microcapsules are oriented horizontally with respect to the magnetic recording layer,
Alternatively, an image is recorded by the contrast of reflected light by orienting vertically, and multicolor color display can be performed by combining each color of yellow (Y), magenta (M), cyan (C), and black (Bk), and a clear image can be obtained. Color display is possible. In particular, a magnetic recording medium that has a clear contrast (brightness and darkness) so that a portion to which magnetism is applied and a portion to which no magnetism is applied is clear, has a high resolution, is clear, and has excellent image stability, and which can be repeatedly recorded and erased. Is.

Further, the magnetic recording medium of the present invention can easily form an image by heating at a low temperature and applying a magnetism, so that the energy consumption is low, and by using the microcapsule for the recording layer, the microcapsule can be used. The resolution can be increased by controlling the particle size of the. Moreover, since the magnetic particles are dispersed in the dispersion medium that is in a solid state at room temperature in the microcapsule and are fixed except during recording and erasing, even if external magnetism is applied after recording the information, the inside of the microcapsule remains Stable recording can be obtained without causing movement of the magnetic particles. Since the movement (orientation) of the magnetic particles can be substantially limited only to the portion to which heating / magnetism is applied, the stability of the image is excellent by using a dispersion medium having a high resolution and showing a solid state at room temperature.

Further, since the step of applying the coating liquid containing the microcapsules can be carried out, the manufacturing step of the magnetic recording body can be simplified.

[Brief description of the drawings]

FIG. 1 is a plan view of an embodiment of a magnetic recording body of the first invention of the present invention.

FIG. 2 is a cross-sectional view taken along line XX of FIG.

FIG. 3 is a cross-sectional view showing an unrecorded state of the magnetic recording body of the first invention of the present invention.

FIG. 4 is a sectional view of the magnetic recording medium of the first invention of the present invention during recording.

FIG. 5 is a cross-sectional view showing an example of microcapsules used in the magnetic recording layer of the magnetic recording medium of the present invention.

FIG. 6 is an enlarged plan view in which an arrangement pattern of a pattern forming layer of the magnetic recording medium of the present invention is partially enlarged.

FIG. 7 is a plan view showing an embodiment of the magnetic recording medium of the second invention of the present invention.

8 is a cross-sectional view taken along line YY of FIG.

[Explanation of symbols]

 1, 2 Magnetic recording medium 11 Support 12 Pattern forming layer 13 Magnetic recording layer 14 Protective layer 15 Microcapsule 16 Binder 17 Mark 21 Core substance 22 Flake magnetic particles 23 Dispersion medium 24 Shell substance 30 Thermal / magnetic head A, B image

Claims (8)

[Claims] 1. Yellow (Y), magenta (M), cyan (C), black (B) on a support made of a non-magnetic material.
The microcapsules enclosing at least a flake-shaped magnetic particle and a dispersion medium that is in a solid state at room temperature and is dispersed in a binder are dispersed and arranged in a binder. And a magnetic recording layer formed by laminating the magnetic recording layer. 2. Microcapsules containing at least flake-shaped magnetic particles and a dispersion medium which is in a solid phase state at room temperature and is dispersed in a binder on a support made of a non-magnetic material. And a pattern forming layer formed of a pattern in which colors of yellow (Y), magenta (M), cyan (C), and black (Bk) are arranged. . 3. The pattern according to claim 1, wherein the pattern is formed by arranging each color of yellow (Y), magenta (M), cyan (C), and black (Bk) as one unit. 2. The magnetic recording material according to 2. 4. The melting point of the dispersion medium is 35 ° C. or higher and 100 ° C.
The magnetic recording medium according to claim 1 or 2, which is an organic compound within the following range. 5. The average particle size of the microcapsules is 10 μm.
The magnetic recording medium according to claim 1 or 2, wherein the magnetic recording medium has a thickness of between m and 1000 µm. 6. The average major axis of the flaky magnetic particles is 5 μm.
3. The magnetic recording medium according to claim 1, wherein the magnetic recording medium has a thickness of m to 30 μm and an average thickness of 0.1 μm to 5 μm. 7. The magnetic recording medium according to claim 1, wherein a protective layer is formed on the magnetic recording layer. 8. A support made of a non-magnetic material, and yellow (Y) / magenta (M) / cyan (C) / black (B).
(k) A magnetic layer formed by dispersing and arranging a pattern forming layer in which a pattern of each color is formed, microcapsules containing flake-shaped magnetic particles and a dispersion medium that is in a solid phase state at room temperature in a binder. A method for recording a magnetic recording medium having a recording layer, wherein the pattern forming layer is formed on the magnetic recording layer obtained by orienting the flaky magnetic particles in the microcapsules in the entire region in a horizontal or vertical direction. Visible information is recorded by partially heating and melting the dispersion medium of the magnetic recording layer in each pattern unit of each color to be formed and magnetically applying in a vertical or horizontal direction to orient the flake-shaped magnetic particles in different directions. A recording method for a magnetic recording body, which is characterized in that