JP3322425B2 - Magnetic recording medium and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a magnetic recording medium and a method of manufacturing the same, and more particularly, to a magnetic recording medium having a permanent magnetic pattern formed thereon and a method of manufacturing the same.

[0002]

2. Description of the Related Art In a magnetic recording medium such as a magnetic card,
There is known a magnetic card or the like in which a permanent magnetic pattern is formed for identification. Conventionally, as a method of forming such a permanent magnetic recording pattern, a method of forming a magnetic pattern by printing such as a MICR character or a magnetic bar code, an opening of a punched hole in a magnetic layer, a laser of a magnetic layer, a needle, etc. There has been a method of forming a magnetic pattern by destruction by a magnetic field.

[0003]

However, in the case of the former method, it is necessary to form a nonmagnetic dummy pattern in order to prevent the pattern from being visually identified, and this dummy pattern is formed of the same ink as the magnetic pattern. If not, there is a problem that the magnetic pattern can be easily determined.

[0004] In the latter case, there is a problem that the magnetic pattern can be easily identified because the pattern is formed by destruction of the magnetic layer.

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic recording medium which solves the above-mentioned problems of the conventional magnetic pattern and makes it more difficult to determine the magnetic pattern, and a method of manufacturing the same.

[0006]

According to the present invention, there is provided a base material, a thermoplastic magnetic layer formed on the base material and magnetically oriented in a predetermined direction, and a heat resistant material formed on the magnetic layer. Between the protective layer and the substrate and the magnetic layer, or between the protective layer and the magnetic layer.
Sensitizing buff formed in at least one of the layers
The magnetic layer is such that a portion heated via the protective layer is disturbed in magnetic orientation and is magnetically oriented in a certain direction except for the heated portion.

Further, according to the present invention, a method for manufacturing a magnetic recording medium having a permanent magnetic pattern formed thereon comprises applying a magnetic paint containing magnetic powder to a base material, magnetically orienting the base material in a certain direction, and then drying. Forming a thermoplastic magnetic layer by
The magnetic layer, forming a highly heat-resistant protective layer, group
Between the material and the magnetic layer or between the protective layer and the magnetic layer.
Forming a buffer layer for sensitization on at least one side,
A step of partially heating the magnetic layer from the surface of the protective layer via the protective layer, melting the heated portion of the magnetic layer to make the magnetic orientation random, and cooling the magnetic layer to form a random magnetic orientation. Fixing step.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a magnetic recording medium according to the present invention.

One embodiment of the magnetic recording medium according to the present invention is shown in FIG. As shown in the figure, in the magnetic recording medium, magnetic layers 14 and 15 are sequentially formed on a base material 12, and a concealing layer 20 and a protective layer 22 are sequentially formed on the magnetic layer 15. The magnetic layer 15 is a thermoplastic magnetic layer made of a magnetic powder and a thermoplastic binder, and has a fixed direction except for a portion heated by a thermal head via the protective layer 22. Magnetic orientation. In the portion 15a of the magnetic layer 15 heated by the thermal head, the magnetic orientation is disturbed by the heating, the magnetization direction becomes random, and the magnetic orientation is not fixed in a certain direction.

As described above, in the magnetic recording medium, the permanent magnetic pattern is formed on the magnetic layer 15 in response to heating by the thermal head. Note that the magnetic layer 14 may be omitted.

Next, a method for manufacturing such a magnetic recording medium will be described.

First, as shown in FIG. 2A, a magnetic layer 14 is formed by applying a magnetic paint containing a magnetic powder and a binder on a base material 12 such as a PET film. As shown, magnetic orientation is performed in a fixed direction A. As the magnetic paint, a two-pack type with a hardener added is usually used.

Next, as shown in FIG. 2B, a magnetic layer 15 is formed by applying a magnetic paint having thermoplasticity in the same manner as described above, and the magnetic layer 15 is oriented in a certain direction similarly to the magnetic layer 14. A is magnetically oriented. Further, a protective layer 22 is formed on the magnetic layer 15.

Thereafter, when the magnetic layer 15 is partially heated from above the protective layer 22 by a thermal head (not shown),
As shown in FIG. 2C, the heated hatched portion 15a of the magnetic layer 15 is in a state where the thermoplastic binder is melted by heating and the orientation of the magnetic powder is disturbed. Thereafter, when cooled, the magnetic layer 15 is solidified, and a magnetic recording medium is manufactured.

According to such a magnetic recording medium, the portion of the magnetic layer 15 melted by the heating of the thermal head is disturbed in the orientation, and the other portions are magnetically oriented in a certain direction. Since these orientation patterns are not changed by subsequent printing or the like, they can be used as permanent magnetic patterns. When the magnetic recording medium thus manufactured as shown in FIG. 3 is magnetized by a predetermined magnetic field (the rightward magnetization is plus), the magnetization of the magnetic layer 15 is heated as shown in FIG. Only the portion 15a in which the magnetic orientation is disturbed has a small degree of magnetization. Therefore, a magnetic pattern can be identified by detecting the degree of such magnetization using magnetic detection means.

According to the magnetic recording medium manufactured by the above method, since it is difficult to visually discriminate the permanent magnetic pattern, illegal use can be effectively prevented.

The orientation of the magnetic layers 14 and 15 is parallel to the surface of the substrate 12 in the above embodiment, but may be perpendicular.

The case where the method for manufacturing a magnetic recording medium according to the present invention is applied to the manufacture of a magnetic card will be described in detail with reference to a more specific example.

First, as the base material 12, for example, a thickness 188
μm white PET film, E-22 manufactured by Toray Industries, Inc.
E-24 or the like is prepared. As the substrate 12, a material used as a substrate in an ordinary card, for example, high-quality paper, resin-impregnated paper, laminated paper, synthetic paper, polyester, or the like can be used.

Next, a magnetic layer 14 is formed by coating a magnetic paint. For example, a magnetic ink having the following composition can be used. Magnetic powder Barium ferrite powder manufactured by Toda Kogyo Co., Ltd. MC-127 100 parts Dispersant Toho Kagaku product name Phosphanol RE-960 3 parts Binder Union Car Band Co., Ltd. VAGH 12.5 parts Nippon Polyurethane N-2304 35.7 parts (NV 35% MEK solution) Antistatic agent Brand name VULCAN XC72 3 parts Solvent Cyclohexanone 67 parts Toluene 33 parts Methyl ethyl ketone 10 parts

The above composition is made into ink in advance, and the following curing agent is added immediately before coating. Curing agent N-3041, 8 parts, made by Nippon Polyurethanes (NV50%)

Further, as the above-mentioned magnetic powder, a magnetic powder usually used for a magnetic recording medium can be used.
BaFe ₁₂ O ₁₉ , γ-Fe ₂ O ₃ , α-Fe, Co-γ-Fe ₂
Magnetic powders such as O ₃ , Fe ₃ O ₄ , and CrO ₂ can be used.

In this embodiment, the coating method is a reverse roll method, but other coating methods such as a gravure method and a wire bar method can be used.

At the time of coating, the magnetic field is oriented in the film flow direction. In this example, a horizontal magnetic field of 5000 Oe by a permanent magnet was used as the orientation magnetic field.
The orientation may be any direction such as a vertical direction and an oblique direction, but is preferably a horizontal direction (longitudinal direction of the card) or a vertical direction.

The coating was performed at a speed of 20 m / min. After the coating, the coating was dried at 100 ° C. for 2 minutes. The obtained coating film had a dry film thickness of 8 μm and a residual magnetic flux of 1.1 Mx / c.
m, the squareness ratio was 0.90, and the coercive force was 2,750 Oersteds. The magnetic layer 14 was sufficiently aged and cured to have heat resistance.

Next, a magnetic paint is coated to form a magnetic layer 15. As this magnetic ink, the one having the following composition can be used similarly to the ink for forming the magnetic layer 14 described above. However, the above-mentioned curing agent is not added to make it thermoplastic. Magnetic powder Barium ferrite powder manufactured by Toda Kogyo Co., Ltd. MC-127 100 parts Dispersant Toho Kagaku product name Phosphanol RE-960 3 parts Binder Union Car Band Co., Ltd. VAGH 12.5 parts Nippon Polyurethane N-2304 35.7 parts (NV 35% MEK solution) Antistatic agent Brand name VULCAN XC72 3 parts Solvent Cyclohexanone 67 parts Toluene 33 parts Methyl ethyl ketone 10 parts

Further, as the above-mentioned magnetic powder, a magnetic powder usually used for a magnetic recording medium can be used.
BaFe ₁₂ O ₁₉ , γ-Fe ₂ O ₃ , α-Fe, Co-γ-Fe ₂
Magnetic powders such as O ₃ , Fe ₃ O ₄ , and CrO ₂ can be used.

The coating method is the same as that of the magnetic ink. As the orientation magnetic field, 5000
Oersted's horizontal magnetic field was used. 20 coatings
m / min, and after coating,
Dried for minutes. The obtained coating film had a dry film thickness of 4 μm, a residual magnetic flux of 0.5 Mx / cm, a squareness ratio of 0.89, and a coercive force of 27.
00 Oersted.

After drying, the sheet is cut. This length is arbitrary. In this case, since the hardening agent is not added to the magnetic layer 15, the magnetic layer 15 is thermoplastic and has poor heat resistance. When the sheet is cut, as shown in FIG. 2A, a magnetic pole is generated in a cross section in the longitudinal direction of the sheet. In the case of the figure, the N pole is generated at the right end and the S pole is generated at the left end. However, depending on the direction of the aligning magnetic field, it may be generated in the opposite direction.

Although the magnetic layers 14 and 15 are formed over the entire length of the card in the above embodiment, they may be formed partially.

Further, a protective layer 22 is formed on the magnetic layer 15. As a material of the protective layer 22, those conventionally used as a protective layer in this type of magnetic recording medium, for example, a cellulose resin, a urethane resin, a polyester resin, a vinyl resin, an epoxy resin, an acrylic resin, Silicone resin, fluorine resin, or the like can be used. Silicones, waxes and the like can be added to impart lubricity. As an extender, Ca
CO ₃ , MgCO ₃ , BaSO ₄ , SiO ₂ , Al ₂ O ₃ , diatomaceous earth, talc, etc. may be added. Further, an antistatic agent may be added to prevent charging. In addition, an ultraviolet curable resin or an electron beam curable resin can also be used, and acrylic resin, epoxy resin, polyester resin, or the like can be used as the ultraviolet curable resin.

In this embodiment, the protective layer 22 is formed by printing. As the ink used for the protective layer 22, a commonly used ink is used, for example, a UV anchor ink, a UV anchor No. manufactured by T & K TOKA. 7
Is UV-printed to a thickness of 1 μm, then UVOP
Ink, T & K TOKA UV peel wet OP
The varnish UP-2 is similarly subjected to UV offset printing to a thickness of 1 μm to form a protective layer 22 having a total thickness of 2 μm. Thereafter, the card is punched by a punching machine into a predetermined size of the card, for example, a size specified in JIS X-6311, to obtain a magnetic card.

In order to perform permanent magnetic recording, the magnetic layer 15 is partially heated to a desired pattern via the protective layer 22 by, for example, a thermal head. The thermal head preferably has a higher resolution, and is 8 dots / mm rather than 6 dots / mm.
Is better. Heating printing energy is 1mJ / dot
However, if the temperature is too high, it is not preferable because the life of the thermal head is shortened and the protective layer is damaged.

When heated by the thermal head, the magnetic layer 15
The heated portion 15a is melted. Therefore, as shown in FIG. 6, the orientation of the magnetic powder in this portion is disturbed, and the direction of magnetization is random. In the portion that is not heated, the direction of magnetization is aligned in the longitudinal direction. Such a difference in the direction of magnetization is detected by the detecting means as a difference in the saturation magnetization value, as shown in FIG. 4 described above, so that the magnetic pattern can be identified.

Thereafter, the magnetic layer 15 is solidified by cooling. As a result, the oriented part and the disordered part are hardened and fixed, respectively.

The magnetic card manufactured in this manner is
When read by the magnetic head 30 as shown in FIG. 7, a detection voltage e as shown in FIG. 7 is obtained. That is, when the card is transported in the longitudinal direction and the magnetic head 30 is arranged at the position of the magnetic track 24 shown in FIG. 5, a detection voltage e is obtained. As can be seen from FIG. 5, the unheated portion is DC magnetized and the heated portion is not magnetized, so that output pulses as shown in FIG. 5 are obtained at both ends of the heated portion.

As described above, since the detection voltage e corresponding to the heating pattern is obtained, the permanent magnetic pattern can be detected. The output pulse is easier to detect if the azimuth of the magnetic head and the inclination of the edge of the heating pattern are matched.

In such a magnetic card, digital data can be formed by changing the position and width of the heating pattern in various ways and can be used as security data of the card. The portion without a pattern is used for normal magnetic recording.

FIG. 8 shows another embodiment of the magnetic recording medium according to the present invention. In this embodiment, the substrate 12
A buffer layer 28 is provided between the magnetic layer 15 and the magnetic layer 15. The buffer layer 28 is a sensitizing layer made of a thermoplastic resin, and can increase the sensitivity at the time of heating by the thermal head. Examples of the material of the buffer layer 28 include an acrylic resin, a polyester resin, a vinyl chloride resin, a vinyl acetate resin, a polystyrene resin,
A thermoplastic resin such as a polybutyral resin can be used. The thickness of the buffer layer 28 is, for example, 0.5 to 8
It is about μm.

The buffer layer 28 may be provided between the magnetic layer 15 and the protective layer 22, or may be provided between the base 12 and the magnetic layer 15 and between the magnetic layer 15 and the protective layer 22. The buffer layer 28 may be provided on both sides.

Further, if necessary, other layers such as a concealing layer and a printing layer may be provided.

[0042]

According to the present invention, a permanent magnetic pattern whose magnetic pattern is difficult to determine can be formed. Further, since the magnetic pattern is formed by heating with the thermal head, the formation of the magnetic pattern is easy. Furthermore, since there is provided a heat-resistant protective layer, the protective layer is not deformed by heat can not irregularities on the surface of the protective layer, also has established a thermoplastic magnetic layer, the substrate and the magnetic layer Or between the protective layer and the magnetic layer
Forming a buffer layer for sensitization on at least one of
High sensitivity when heating with a thermal head
The magnetic pattern can be easily formed without impairing the smoothness of the protective layer. Further, an arbitrary magnetic pattern unique to the magnetic recording medium can be given at the time of issuing (rowing) the magnetic recording medium.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a magnetic recording medium according to the present invention.

FIG. 2 is a sectional view showing a manufacturing process of the magnetic recording medium according to the present invention.

FIG. 3 is a cross-sectional view illustrating a process of manufacturing a magnetic recording medium according to the present invention.

FIG. 4 is a diagram showing an example of a magnetization characteristic of a magnetic recording medium according to the present invention.

FIG. 5 is a diagram showing an embodiment in which the magnetic recording medium according to the present invention is applied to a magnetic card.

FIG. 6 is a diagram showing a state of magnetic orientation in a process of manufacturing a magnetic recording medium according to the present invention.

FIG. 7 is a diagram showing an example of output characteristics of a magnetic recording medium according to the present invention.

FIG. 8 is a sectional view showing another embodiment of the magnetic recording medium according to the present invention.

[Explanation of symbols]

 Reference Signs List 12 base material 14 magnetic layer 15 magnetic layer 22 protective layer 24 magnetic track 28 buffer layer 30 magnetic head

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI G11B 5/80 G11B 5/84 Z 5/84 G06K 19/00 B

Claims (2)

(57) [Claims] And 1. A base material is formed on the substrate, a thermoplastic magnetic layer is magnetically oriented in a predetermined direction, are formed on the magnetic layer, and a highly heat-resistant protective layer, wherein the group Between the material and the magnetic layer or in front of the protective layer
Sensitizing layer formed on at least one of the magnetic layers.
A buffer layer, wherein the magnetic layer has a portion heated via the protective layer disturbed in the magnetic orientation and is magnetically oriented in the fixed direction except for the heated portion. Characteristic magnetic recording medium. 2. A method for manufacturing a magnetic recording medium having a permanent magnetic pattern formed thereon, comprising: applying a magnetic coating material containing magnetic powder to a base material; A step of forming a thermoplastic magnetic layer, a step of forming a heat-resistant protective layer on the magnetic layer, and between the base and the magnetic layer or before the protective layer.
A buffer layer for sensitization in at least one of the magnetic layers
Forming, and partially heating the magnetic layer from the surface of the protective layer via the protective layer, and melting the heated portion of the magnetic layer to randomize the magnetic orientation, Cooling the magnetic layer and fixing the random magnetic orientation.