JP2844888B2 - Discharge breakdown magnetic recording media - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a discharge breakdown magnetic recording medium, in particular, to surely conceal a magnetic recording layer and to form a fine linear uneven pattern group on the magnetic recording layer. Discharge breakdown magnetism that has a fine concavo-convex pattern (an image having an opal effect, hereinafter referred to as an opal image) formed by shaping a plurality of lines by slightly changing the line for each pixel, and capable of performing visual recording. It relates to a recording medium.

<Prior art> Magnetic recording media are easy to write, read, and rewrite information, can be machine-processed, and can be manufactured at low cost.
It is widely used for prepaid cards such as cards, commuter passes, and telephone cards.

In recent years, in addition to recording fixed information or identification information or variable information on the magnetic recording layer, and for the convenience of the card holder,
Information that can be viewed at the time of use (hereinafter referred to as visible information) is recorded on the surface of the card. In particular, in a prepaid card, the same value information as that of magnetic recording can be visually recognized without being read. It has become possible. The conventional thermosensitive recording layer utilizing the thermosensitive coloring effect is provided on a substrate opposite to the magnetic recording layer or does not overlap with the magnetic recording layer as a recording means visible on a magnetic recording medium having a magnetic recording layer. Part was provided. For this reason, when the magnetic recording layer surface occupies a large area, there is a drawback that when printing pre-printed characters, patterns, etc. as visible information, and when the visible information is recorded later with a thermal head or the like, the recording space is restricted. . Therefore, Japanese Patent Laid-Open No. 52-1143
There is a thermosensitive magnetic recording medium in which a thermosensitive recording layer is directly formed on a magnetic recording layer, as described in JP-A-33-339 and JP-A-59-199285.

<Problems to be solved by the invention> However, in a thermosensitive magnetic recording medium in which a thermosensitive recording layer is formed directly on the magnetic recording layer as described above, only magnetic information and print information are present on the magnetic recording layer side. There was no effective means to impart aesthetic and decorative properties to the surface. SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and provides a three-dimensional image information of an image forming body having an opal effect for giving aesthetics and decorativeness by using the same material together with magnetic recording on the same surface side of a substrate. And a magnetic recording medium capable of forming visible information.

<Means for Solving the Problems> According to the present invention, which has been made to achieve the above object, at least a magnetic recording layer, a conductive metal thin film layer, and a conductive resin layer are sequentially laminated on at least a substrate. In the magnetic recording medium, a plurality of fine linear uneven patterns set at a desired angle are combined with each other by changing the direction of each parallel line, and the fine uneven pattern is at least the conductive metal thin film layer having the conductivity. A discharge breakdown magnetic recording medium characterized by being shaped above.

<Operation> According to the present invention, the magnetic recording layer can be reliably concealed by the metal thin film layer, and the three-dimensional image information of the opal image and the discharge breakdown recorded image of the same material formed on the same surface of the recording medium can be obtained. On the other hand, high contrast is obtained for each. Further, by providing the three-dimensional image information of the opal image on the magnetic recording surface, it is possible to design the non-magnetic recording surface on the opposite side, and it is possible to provide a magnetic recording medium having a more decorative effect.

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a partially enlarged cross-sectional view of a discharge breakdown magnetic recording medium (1) of the present invention, wherein at least a magnetic recording layer (3), a conductive metal thin film layer (5), and a conductive layer are formed on a substrate (2). Is provided. The magnetic recording layer (3) may be a part on the substrate (2) or the whole surface. The conductive metal thin film layer (5) may have the same size as the magnetic recording layer (3) or may be larger than the magnetic recording layer (3). Further, each layer can be formed via an adhesive as needed.

As the substrate (2), plastics such as polyvinyl chloride, polyester, polycarbonate, polymethyl methacrylate, and polystyrene, paper, synthetic paper, and the like can be used alone or as a composite. The substrate (2) has physical properties required according to the use of the recording medium, such as a card or a sheet.
For example, it is possible to select from the above materials in consideration of the strength, rigidity, concealing property, light opacity and the like. The magnetic recording layer (3) is made of, for example, γ-Fe ₂ O ₃ , Co-coated γ-Fe ₂ O ₃ , Fe ₃ O ₄ , CrO ₂ , Fe, Fe-Cr, Fe-Co, Co-Cr, Co- N
It is composed of a magnetic fine particle dispersion of i, MnAl, Ba ferrite, Sr ferrite and the like. Generally, a magnetic recording layer (3) used for a magnetic recording medium such as a prepaid card has a holding power of 1500 to 3000.
(Oe), the residual magnetic flux is 1.0 to 2.0 (Maxwell / cm).

The conductive metal thin film layer (5) is preferably a white non-magnetic and conductive metal thin film layer. As this kind of metal, there is aluminum. This layer is formed by a vacuum deposition method, a sputtering method, an ion plating method, or the like, and has a thickness of 0.03 to 0.1 μm.

The conductive resin layer (6) is mainly composed of, for example, an acrylic resin, a urethane resin, a cellulose acetate resin, a nitrocellulose resin, or the like. Disperse to some extent to form an ink, apply by a known coating method such as bar coating, blade coating, air knife coating, gravure coating, solvent coating such as roll coating, or screen printing, and form by drying. 0.5-5μm
And

The stamper used for molding the opal image is formed of a copper plate, and is composed of a group of line-shaped concavo-convex patterns in which the direction, pitch and depth are slightly changed.The embossed surface is nickel-plated, and the pitch of the groove is It is preferable that the depth is about 100 μm and the depth of the unevenness is 10-20 μm. An opal image is formed by heating and pressing the conductive metal thin film layer (5) side using this stamper. This step can be performed before or after providing the conductive resin layer (6). You may go after. Further, a resin layer (4) may be provided between the magnetic recording layer (3) and the conductive metal thin film layer (5) as shown in FIG. 1 in order to further enhance the moldability.

Further, a lubricant can be added to the conductive resin layer (6) for the purpose of improving the suitability for the discharge breakdown head. In consideration of magnetic properties, it is preferable that each layer on the magnetic recording layer (3) is as thin as possible, and the total thickness is desirably 10 μm or less.

Thus, a discharge breakdown magnetic recording medium can be obtained.

Next, a specific example will be described with reference to the following example. In the examples, "parts" indicates "parts by weight".

Example 1 (1) Byron manufactured magnetic recording composition BaO-6Fe ₂ O ₃ 40 parts of salt vinyl resin 10 parts of acetic acid in the magnetic paint (Sekisui Chemical Co., Ltd., S-LEC A) Saturated polyester resin 5 parts (Toyobo Co., 103) Polyurethane elastomer 7 parts (N-2304 manufactured by Nippon Polyurethane Co., Ltd.) Oleic acid 5 parts Toluene 30 parts Ethyl isobutyl ketone 30 parts Isocyanate curing agent 3 parts (Nippon Polyurethane Co., Ltd. Coronate HL) Triethylene diamine 0.5 part ( 2) Composition of coating liquid for conductive resin layer 1 part of zinc stearate 8 parts methacrylic resin 8 parts (Paraloid A-11 manufactured by ROHM & HARAS) 9 parts of toluene 5 parts of silver powder 5 parts on a 188 μm thick white PET sheet (1) Was applied by a gravure coating method to form a magnetic recording layer having a thickness of 15 μm. Next, a urethane-based resin is applied by a gravure coating method to form a resin layer having a thickness of 3 μm, and the resin layer is dried and cured. Then, aluminum is evaporated to a thickness of 0.05 μm by a vacuum evaporation method to form a conductive metal. A thin film layer was formed. Further, a conductive resin layer paint having the composition of the above (2) was applied by a gravure coating method, and dried to form a film having a thickness of 2 μm. On top of this, an opal image was formed at 70 ° C. with an opal image forming stamper having a cross-sectional configuration as shown in FIG. 2 to obtain an opal image having a depth of irregularities of 4 μm, which was used as a discharge breakdown magnetic recording medium of the present invention.

In the discharge breakdown magnetic recording medium having the configuration of the above embodiment, the magnetic recording layer could be reliably concealed by the metal thin film layer. Also,
When discharge recording was performed on the recording medium from the conductive resin layer side, high contrast was obtained for each of the opal image and the discharge breakdown recorded image formed by the metal thin film layer formed on the same surface of the recording medium. When magnetic recording and reading were performed on this recording medium, 4 μm of the opal image was obtained.
There was almost no effect of the unevenness of m on the magnetic properties because the pitch of the grooves of the opal image was around 100 μm.

<Effects of the Invention> According to the present invention, a magnetic recording layer can be reliably concealed by a metal thin film layer, and three-dimensional image information of an opal image and discharge breakdown recording using the same material formed on the same surface of a recording medium. High contrast is obtained for each image. In addition, the provision of the opal image makes it extremely easy to identify the recording medium, enhances aesthetics and decorativeness, and enhances the effect of preventing forgery. Furthermore, by providing the three-dimensional image information of the opal image on the magnetic recording layer, a different design can be applied to the non-magnetic recording surface on the opposite side, and a magnetic recording medium having a more decorative effect can be provided. Can be provided.

[Brief description of the drawings]

FIG. 1 is a partially enlarged sectional view showing the structure of a discharge breakdown magnetic recording medium according to an embodiment of the present invention, and FIG. 2 is a sectional view of an opal stamper. (1) Discharge breakdown magnetic recording medium (2) Substrate (3) Magnetic recording layer (4) Resin layer (5) Conductive metal thin film layer (6) Conductivity Resin layer

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G11B 5/80 B42D 15/10

Claims (1)

(57) [Claims] 1. A magnetic recording medium comprising at least a magnetic recording layer, a conductive metal thin film layer, and a conductive resin layer sequentially laminated on at least a substrate, wherein a fine linear shape set at a desired angle is provided. A discharge characterized in that a fine uneven pattern formed by combining a plurality of uneven pattern groups by changing the direction of each parallel line is formed at least on a conductive metal thin film layer on the magnetic recording layer. Destructive magnetic recording medium.