JPH1021358A - Magnetic card and its forgery preventing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the recording and reproducing of new information to a used magnetic card by including thermoplastic resin irreversibly changing its shape by heating to not lower than a prescribed temperature in the magnetic layer of a magnetic card. SOLUTION: The magnetic card is provided with a substrate 10 consisting of resin and a thermoplastic magnetic layer 40. The layer 40 includes a magnetic material for magnetically recording/reproducing information and thermoplastic resin irreversibly changing its shape by heating to not less than the prescribed temperature. At the time of recording initial information and then successively recording new information to this magnetic card, a part corresponding to a part for which reproducing, etc., is not to be executed again, etc., among the layer 40 including thermoplastic resin is shape-changed each time of using. Namely by heating the part for which reproducing, etc., is not to be executed again, among the layer 40 including thermoplastic resin, it is made impossible to reproduce information at the part and to re-record it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a magnetic card for recording / reproducing information, and more particularly to an improvement of a forgery prevention technique.

[0002]

2. Description of the Related Art A magnetic card used as a so-called cash voucher such as a ticket, a telephone card, a prepaid card, or the like is used by a predetermined device every time the magnetic card is used. It is used by rewriting predetermined information such as the balance. In order to prevent forgery, these magnetic cards are provided with a protective layer on the magnetic recording layer, a multilayered magnetic recording layer, or a punched hole in the card for each use. .

[0003]

By the way, with the spread of magnetic cards, device technology for recording / reproducing information on magnetic cards has also been developed. As a result, information recorded on magnetic cards is read, and further information is read. Writing is easy to do.

[0004] Basically, a magnetic card is
This is a recording format in which all information including new information is rewritten so as to overwrite old information. Therefore, if there is a device for recording / reproducing information on the magnetic card,
Information can be easily rewritten. As a result, the forgery of the card can be easily performed, and the forgery of the magnetic card in recent years has been significantly increased.

[0005] This is because the used magnetic card is only supposed to be unable to use the recorded information, and the reproduction and re-recording of the information of the magnetic card itself are substantially possible.

[0006] It is an object of the present invention to provide a magnetic card in which recording / reproduction of new information on a used magnetic card is disabled and a method for preventing forgery thereof.

[0007]

According to the present invention, there is provided a magnetic card having a magnetic layer formed on a substrate and for magnetically recording / reproducing information, wherein the magnetic layer has a temperature higher than a predetermined temperature. A magnetic card containing a thermoplastic resin whose shape changes irreversibly when heated is obtained.

[0008] According to the present invention, also formed on a substrate,
In a magnetic card having a magnetic layer for magnetically recording / reproducing information and a protective layer formed on the magnetic layer to protect the magnetic layer, the magnetic card includes a magnetic layer and a protective layer. A magnetic card is obtained, characterized in that at least one of the magnetic cards contains a thermoplastic resin which changes its shape irreversibly when heated above a predetermined temperature.

According to the present invention, when the magnetic card is used, at least a portion of the layer containing the thermoplastic resin corresponding to a portion of the magnetic layer not to be reproduced again is heated to a predetermined temperature or higher. A method for preventing forgery of a magnetic card, characterized by having a heating step.

According to the present invention, in the heating step,
A method for preventing forgery of the magnetic card, characterized in that the corresponding portion is heated by a laser.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a magnetic card according to an embodiment of the present invention and a method for preventing forgery of a magnetic card using the same will be described.

The forgery prevention method according to the present invention makes it impossible to use at least specific information among information already recorded, that is, makes reproduction and re-recording impossible.

In the forgery prevention method, when new information is sequentially recorded after the initial information is recorded, at least a portion of the layer containing the thermoplastic resin which is not to be reproduced again at every use is used. Change the shape of the corresponding part. That is,
By heating at least a portion of the layer containing the thermoplastic resin corresponding to a portion where reproduction and the like are not performed again, the information of the portion is made unreproducible and re-recording is not possible.

The magnetic card according to the present invention is preferably a magnetic card in which the layer containing a thermoplastic resin changes its form, and the electrical characteristics when magnetically recorded information is read greatly change. Examples of the morphological change of the layer containing the thermoplastic resin include deformation and removal of the layer. Furthermore, when two or more layers are each made of a thermoplastic resin, mixing of adjacent layers can be considered. In any of these morphological changes, the layer containing the thermoplastic resin whose morphology has been changed by heating on the substrate significantly changes the electrical characteristics during recording / reproduction. Thus, information magnetically recorded on the layer containing the thermoplastic resin is generally detected only as noise when the information is reproduced. On the other hand, during recording, noise is superimposed, and so accurate recording cannot be performed. Furthermore, since this morphological change is irreversible, it is not possible to reconstitute the layer containing the thermoplastic resin.

As the thermoplastic resin contained in the layer containing the thermoplastic resin of the magnetic card of the present invention, a resin whose thermal softening temperature is lower than the deformation temperature of the substrate and higher than the operating temperature range of the card is used. Appropriate. In addition, the more excellent the fluidity of the resin, the greater the morphological change after heating.
This is preferable because the change in electrical characteristics during reproduction is large. As a heating method of the layer containing the thermoplastic resin, there are a heater heating and a laser heating. However, it is possible to heat the layer to a desired temperature in a short time. Heating is preferred.

[0016]

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

FIGS. 1A to 1D are longitudinal sectional views showing the structure of a magnetic card according to each embodiment of the present invention. In the drawings, the same or similar parts as those of the other embodiments are denoted by the same reference numerals.

Embodiment 1 Referring to FIG. 1A, a magnetic card according to Embodiment 1 of the present invention has a substrate 1 made of resin.
0, and a thermoplastic magnetic layer 40 formed on the substrate 10. The thermoplastic magnetic layer 40 contains a magnetic material for magnetically recording / reproducing information, and a thermoplastic resin which changes its shape irreversibly when heated to a predetermined temperature or higher.

Next, a method of manufacturing the magnetic card will be described.

BaCo ₃ and Fe ₂ O ₃ were mixed and pulverized using a ball mill, and the obtained powder was subjected to a heat treatment to obtain a Ba-M type ferrite.

The obtained powdery Ba-M type ferrite, polystyrene (thermosoftening temperature: about 80 ° C.) as a thermoplastic resin, and a solvent were mixed to obtain a thermoplastic magnetic paint.

The obtained thermoplastic magnetic paint is coated on a substrate 10 made of polyethylene terephthalate (PET).
Coating was performed so as to have a thickness of 20 μm, and further drying was performed to form a thermoplastic magnetic layer 40 on the substrate 10, thereby manufacturing a magnetic card. A plurality of such magnetic cards were manufactured.

When a conventional reader / writer (recording magnetic field: 5 kG) was used to record and reproduce data from each of the manufactured magnetic cards, a good recording signal was detected in each of the cards.

Next, the thermoplastic magnetic layer 40 of each magnetic card
Are respectively 70, 80, 90,
Heated to 100 ° C. Thereafter, when the information recorded as described above was reproduced by the reader / writer, the magnetic card heated to 70 ° C. could reproduce the information. The magnetic card heated to 80 ° C. was able to reproduce information although the noise was slightly increased. In the magnetic card heated to 90 or 100 ° C., only noise was detected in the heated portion, and information could not be reproduced and re-recorded. Further, as a result of re-recording and reproduction of each magnetic card, the magnetic card heated to 70 or 80 ° C. could reproduce information by re-recording. But 90, 1
In the magnetic card heated to 00 ° C., only noise was detected in the heated portion, and information could not be reproduced and re-recorded.

From the experimental results, it can be seen that in the above embodiment, the heating temperature of the magnetic card is preferably 90 ° C. or higher.

[Embodiment 2] Referring to FIG. 1 (b), a magnetic card according to Embodiment 2 of the present invention has a substrate 1 made of resin.
A magnetic layer 20 formed on the substrate 10 and containing a magnetic material for magnetically recording / reproducing information;
And a thermoplastic protective layer 50 formed thereon.
The thermoplastic protective layer 50 contains a resin material for protecting the magnetic layer 20 and a thermoplastic resin that changes its shape irreversibly when heated to a predetermined temperature or higher.

BaCo ₃ and Fe ₂ O ₃ were mixed and pulverized using a ball mill, and the obtained powder was subjected to a heat treatment to obtain a Ba-M type ferrite. Powder B obtained
An a-M ferrite, a resin, and a solvent were mixed to obtain a magnetic paint.

Also, a thermoplastic resin (polystyrene),
The solvent and the powder for the protective layer were mixed to obtain a thermoplastic protective coating.

The obtained magnetic paint was applied on a substrate 10 made of PET so as to have a thickness of 20 μm, and dried to form a magnetic layer 20 on the substrate 10. further,
On the magnetic layer 20, a 10 μm thick thermoplastic protective coating is applied.
, And dried to form a thermoplastic protective layer 50, thereby producing a magnetic card. A plurality of such magnetic cards were manufactured.

When a conventional reader / writer (recording magnetic field: 5 kG) was used to record and reproduce each of the manufactured magnetic cards by the FM method, good recording signals were detected in any of the cards.

Next, a part of the magnetic recording portion of the magnetic layer 20 of each magnetic card was heated to 90 ° C. through the corresponding thermoplastic protective layer 50. Thereafter, when the information recorded as described above was reproduced by the reader / writer, only noise was detected in the heated portion, and the information could not be reproduced and re-recorded. Further, as a result of re-recording and reproducing the data on the card, only noise was detected in the heated portion, and information could not be reproduced and re-recorded.

Third Embodiment Referring to FIG. 1C, a magnetic card according to a third embodiment of the present invention has a substrate 1 made of resin.
0, a thermoplastic magnetic layer 40 formed on the substrate 10,
And a protective layer 30 formed on the thermoplastic magnetic layer 40. The thermoplastic magnetic layer 40 records / records information magnetically.
It contains a magnetic material to be regenerated and a thermoplastic resin whose shape changes irreversibly when heated to a predetermined temperature or higher.

BaCo ₃ and Fe ₂ O ₃ were mixed and ground using a ball mill, and the resulting powder was subjected to a heat treatment to obtain a Ba-M type ferrite. Powder B obtained
The aM type ferrite, polystyrene (thermosoftening temperature: about 80 ° C.) as a thermoplastic resin, and a solvent were mixed to obtain a thermoplastic magnetic paint.

Further, a resin, a solvent, and a powder for a protective layer were mixed to obtain a protective coating.

The obtained thermoplastic magnetic paint is applied on a substrate 10 made of PET so as to have a thickness of 20 μm, and is further dried.
Was formed. Further, a protective paint was applied on the thermoplastic magnetic layer 40 so as to have a thickness of 10 μm, and was further dried to form the protective layer 30, thereby producing a magnetic card. A plurality of such magnetic cards were manufactured.

When a conventional reader / writer (recording magnetic field: 5 kG) was used to record and reproduce each of the manufactured magnetic cards by the FM method, good recording signals were detected in any of the cards.

Next, the thermoplastic magnetic layer 40 of each magnetic card
A part of the magnetic recording portion was heated to 90 ° C. through the protective layer 30. Thereafter, when the information recorded as described above was reproduced by the reader / writer, only noise was detected in the heated portion, and the information could not be reproduced and re-recorded. Further, as a result of re-recording and reproducing the data on the card, only noise was detected in the heated portion, and information could not be reproduced and re-recorded.

Fourth Embodiment Referring to FIG. 1D, a magnetic card according to a fourth embodiment of the present invention has a substrate 1 made of resin.
0, a thermoplastic magnetic layer 40 formed on the substrate 10,
Thermoplastic protective layer 50 formed on thermoplastic magnetic layer 40
And The thermoplastic magnetic layer 40 contains a magnetic material for magnetically recording / reproducing information, and a thermoplastic resin which changes its shape irreversibly when heated to a predetermined temperature or higher. Further, the thermoplastic protective layer 50 includes a resin material for protecting the thermoplastic magnetic layer 40 and a thermoplastic resin whose shape is irreversibly changed when heated to a predetermined temperature or higher.

BaCo ₃ and Fe ₂ O ₃ were mixed and pulverized using a ball mill, and the obtained powder was subjected to a heat treatment to obtain a Ba-M type ferrite. Powder B obtained
The aM type ferrite, polystyrene (thermosoftening temperature: about 80 ° C.) as a thermoplastic resin, and a solvent were mixed to obtain a thermoplastic magnetic paint.

Further, a thermoplastic resin (polystyrene)
The solvent and the powder for the protective layer were mixed to obtain a thermoplastic protective coating.

The obtained thermoplastic magnetic paint is applied on a substrate 10 made of PET so as to have a thickness of 20 μm, and further dried, and a thermoplastic magnetic layer 40 is formed on the substrate 10.
Was formed. Further, a thermoplastic protective paint was applied on the magnetic layer 20 so as to have a thickness of 10 μm, and dried to form a thermoplastic protective layer 50, thereby producing a magnetic card. A plurality of such magnetic cards were manufactured.

When a conventional reader / writer (recording magnetic field: 5 kG) was used to record and reproduce each of the manufactured magnetic cards according to the FM method, good recording signals were detected in any of the cards.

Next, the thermoplastic magnetic layer 40 of each magnetic card
A part of the magnetic recording portion of FIG.
Heated to 0 ° C. Thereafter, when the information recorded as described above was reproduced by the reader / writer, only noise was detected in the heated portion, and the information could not be reproduced and re-recorded. In addition, as a result of re-recording and playback on the card,
Only noise was detected in the heated portion, and information could not be reproduced and re-recorded.

Fifth Embodiment A magnetic card according to a fifth embodiment of the present invention has the same structure as that of the fourth embodiment. That is, referring to FIG. 1D, a substrate 10 made of resin and a substrate 1
0, and a thermoplastic protective layer 50 formed on the thermoplastic magnetic layer 40. The thermoplastic magnetic layer 40 contains a magnetic material for magnetically recording / reproducing information, and a thermoplastic resin which changes its shape irreversibly when heated to a predetermined temperature or higher. In addition, the thermoplastic protective layer 50 is
And a thermoplastic resin which changes its shape irreversibly when heated to a predetermined temperature or higher.

As in the case of the fourth embodiment, a thermoplastic magnetic paint is applied to a thickness of 20 μm on a PET substrate 10 and then dried to form a thermoplastic magnetic layer 40. On top of thermoplastic protective paint 10μ thick
m, and then dried to form a thermoplastic protective layer 5
0 was formed to produce a magnetic card. A plurality of such magnetic cards were manufactured. When a conventional reader / writer (recording magnetic field: 5 kG) was used to record and reproduce each of the manufactured magnetic cards by the FM method, good recording signals were detected in any of the cards.

Next, the thermoplastic magnetic layer 40 of each magnetic card
A portion of the magnetic recording portion was laser-heated through a thermoplastic protective layer 50 using a laser irradiation device. Thereafter, when the information recorded as described above was reproduced by the reader / writer, only noise was detected in the heated portion, and the reproduction and re-recording of the information could not be performed. Further, as a result of re-recording and reproducing the data on the card, only noise was detected in the heated portion, and information could not be reproduced and re-recorded.

When the cross section including the laser-heated portion of the magnetic card was magnified and observed, the portion containing the thermoplastic resin (the thermoplastic magnetic layer 40 and the thermoplastic protective layer 5) was observed at that portion.
0) was less than half the film thickness of 30 μm before heating.

[0048]

According to the magnetic card of the present invention, at least one of the magnetic layer and the protective layer contains a thermoplastic resin which changes its shape irreversibly when heated to a predetermined temperature or higher. Since it is impossible to record / reproduce new information on an already-used magnetic card, it is impossible to write information for forgery, which is industrially useful.

Further, in the method for preventing forgery of a magnetic card according to the present invention, when the magnetic card is used, at least a portion of a layer containing a thermoplastic resin corresponding to at least a portion of the magnetic layer which is not to be reproduced is determined. It has a heating step of heating to a temperature higher than the temperature, and has an effect that forgery of the magnetic card can be prevented with a simple process.

[Brief description of the drawings]

FIGS. 1A to 1D are longitudinal sectional views each showing a structure of a magnetic card according to each embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Substrate 20 Magnetic layer 30 Protective layer 40 Thermoplastic magnetic layer 50 Thermoplastic protective layer

Claims (4)

[Claims] 1. A magnetic card formed on a substrate and having a magnetic layer for magnetically recording / reproducing information,
A magnetic card, wherein the magnetic layer contains a thermoplastic resin which changes its shape irreversibly when heated to a predetermined temperature or higher. A magnetic layer formed on the substrate for magnetically recording / reproducing information; and a magnetic layer formed on the magnetic layer.
In a magnetic card having a protective layer for protecting the magnetic layer, at least one of the magnetic layer and the protective layer has a thermoplastic resin irreversibly changing its shape when heated to a predetermined temperature or higher. A magnetic card comprising a resin. 3. The use of the magnetic card according to claim 1, wherein at least a portion of the layer containing the thermoplastic resin corresponding to a portion of the magnetic layer not to be reproduced again is at a predetermined temperature or higher. A method for preventing forgery of a magnetic card, comprising a heating step of heating the magnetic card. 4. The method for preventing forgery of a magnetic card according to claim 3, wherein in the heating step, the corresponding portion is heated by a laser.