JP2706715B2 - Magnetic recording medium and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic card such as a shopping card, a savings card, a commuter pass, a ticket, a coupon, a pre-paid card, a cash card, a credit card, an identification card, a consultation ticket, a magnetic sheet, and a magnetic roll. The present invention relates to a magnetic recording medium used for paper and the like and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, magnetic recording media such as magnetic recording cards or magnetic roll paper have been increasingly used in various fields. The basic structure is such that a layer of a magnetic material is provided on a substrate made of a non-magnetic material, and this is magnetized. Such magnetic recording media need to prevent unauthorized use due to duplication or falsification of magnetic information, and various measures for preventing unauthorized use have been taken. Typical measures for preventing unauthorized use are roughly classified into a method of making recording and reproduction of magnetic recording information difficult, and a method of providing the magnetic recording medium itself with authenticity determination information. The former is a method of hiding recorded magnetic information and making it difficult to falsify or duplicate magnetic information by making writing and reading of information difficult.
The latter is a method of preventing forgery and falsification by putting identification information for determining whether or not a magnetic card is a legitimate one in the card itself.

[0003]

To describe in more detail, the former known measure for preventing unauthorized use by making recording and reproduction of magnetic recording information difficult is to make the magnetic recording layer multilayer. This makes it difficult to read legitimate information by concealing legitimate information or making it difficult to analyze legitimate information by superimposing dummy information.However, if legitimate information and dummy information are recorded on the same track, Since dummy information is sometimes superimposed on regular information, regular information cannot be read by a normal method. However, there are drawbacks such as a complicated writing / reading device for recording,
Also, once the details of the method of reading the legitimate information are known, anyone familiar with magnetic recording can read the information,
Since analysis is possible, there is a problem that a large amount of magnetic recording media can be copied. On the other hand, in the latter magnetic card itself, which is provided with authenticity determination information, for example, a magnetic recording medium is provided with a barcode that can be read magnetically, and the authenticity of the information is determined based on the barcode information. Since the medium itself has information to determine whether the magnetic recording medium is genuine, it is difficult to duplicate the medium in large quantities and use it improperly. Can not deal with.

[0004]

The magnetic recording medium according to the present invention has the latter function of preventing unauthorized use. However, unlike the conventional magnetic recording medium, different fingerprint information is added to each medium. Is improper to use,
At the same time, the layer formed for imparting the anti-fraud function can also be used as a print recording layer, which is convenient.

The outline of the present invention is as follows. The invention according to claim 1 is characterized in that 20 non-magnetic substrates are provided on the substrate.
A magnetic layer made of a magnetic material having a coercive force of 0 to 5000 Oe and a magnetic thin film layer having a coercive force of 1000 Oe or less are sequentially laminated, and are deposited on the magnetic thin film layer thicker than other portions which cannot be added or erased later. Pattern
A magnetic recording medium characterized by forming fixed information in a shape . According to a second aspect of the present invention, in manufacturing the magnetic recording medium according to the first aspect, a magnetic paint having a coercive force of 200 to 5000 Oe is applied and dried on a nonmagnetic substrate to form a magnetic recording layer .
Thereafter, magnetic recording is performed , and thereafter, a magnetic thin film layer is formed on the magnetic recording layer by at least one method selected from a vapor deposition method, a sputtering method, and a plating method. It is a manufacturing method. According to a third aspect of the present invention, there is provided a magnetic recording medium wherein the magnetic thin film layer of the magnetic recording medium according to the first aspect is printed by a discharge breakdown method.

According to the method of manufacturing a magnetic recording medium of the present invention, magnetic recording is first performed on a magnetic recording layer formed on a nonmagnetic material, and then a magnetic thin film layer is formed thereon. The magnetic metal, magnetic alloy or magnetic compound forming the magnetic thin film layer is deposited thicker on the magnetic flux reversal interface of the magnetic recording layer than other portions to form a pattern. This pattern portion has the same function as a magnetic barcode made of a magnetic metal, a magnetic alloy or a magnetic compound, and can be magnetically detected by a magnetic head or the like. That is, this pattern becomes fixed information that cannot be added or deleted later, and can be used as unauthorized use prevention information of the medium.

In the present invention, the content of the fixed information formed on the non-magnetic thin film is determined by the magnetic recording information performed on the magnetic recording layer. That is, by controlling the magnetic recording information, it becomes possible to add different fixed information to the magnetic recording medium as a final product, for example, for each magnetic card.

Conventionally, such fixed information is formed by a printing method, so that all the same information or limited types of information can be given to each magnetic recording medium. On the other hand, according to the method of the present invention, the recording density of fixed information can be dramatically increased, and more complicated information can be added.

The magnetic information formed in a pattern is preferably used as information for preventing unauthorized use, so that it is preferable that visual confirmation is difficult. In the method of the present invention, it is possible to obtain a sufficient magnetic output even if the fixed information formed in a pattern is extremely thin, and the physical protrusion (thickness) of the pattern portion may be small. It is difficult to visually confirm and concealment is easy. Further, in the method of the present invention, since the layer formed on the magnetic recording layer is a magnetic thin film layer, which is extremely thin, it has almost no adverse effect on ordinary magnetic recording performed on portions other than the fixed information section. There is a feature that there is no. The magnetic thin film layer, apart from that function with a fixed information for formed anti-counterfeiting, in order to also have the functions of printing the recording layer by <br/> electrostatic printing method the magnetic thin film layer is release, For example, it is possible to perform print recording that requires visual observation, such as displaying the balance.

The present invention will be described below with reference to the drawings.
FIG. 1A is a plan view of a magnetic recording medium (card) according to the present invention, and has a magnetic track T. FIG. FIG. 1B is a cross-sectional view taken along the line XX 'of the track T. A magnetic recording layer 2 made of a magnetic material having a coercive force of 200 to 5000 Oe and an adhesion auxiliary layer 3 are formed on a substrate 1 made of a nonmagnetic layer. , 10
It comprises a magnetic thin film layer 4 having a thickness of 00 Oe or less and a protective layer 5 provided as required. A portion T in FIG. 1A is a track of magnetic recording performed on the magnetic recording layer.
P corresponds to the magnetic flux reversal interface of the magnetic recording performed on the magnetic recording layer, and the magnetic thin film layer formed on the magnetic recording layer is thickly deposited on this portion to form a pattern of fixed information. The protective layer 5 may be further printed with graphic characters and the like and a protective film.

Next, the materials constituting the magnetic recording medium of the present invention will be described. First, as a substrate made of a non-magnetic material,
A sheet-like non-magnetic material such as a ceramic film such as a polyester film, a vinyl chloride film, a synthetic paper, a wood pulp paper, a laminated paper, a metal sheet, and a glass having a thickness of 150 μm to 1 mm can be applied. The magnetic material used for the magnetic recording layer laminated adjacent to the substrate is not particularly limited, but is generally a ferromagnetic material having a coercive force of 200 to 5000 Oe, for example, γ-iron oxide, cobalt-doped γ −
Fine powders such as iron oxide, chromium oxide, barium ferrite, and strontium ferrite are used. These magnetic materials are used as binders for vinyl chloride / vinyl acetate copolymers, vinyl chloride / vinyl acetate / vinyl alcohol copolymers, polyurethane resins, polyester resins, epoxy resins, polyisocyanate resins, etc. A magnetic recording layer can be formed by dispersing together with the coating liquid or ink to form a coating liquid or ink and applying or printing the coating liquid or ink on a substrate.
At this time, the magnetic recording layer 2 may be subjected to a magnetic field orientation treatment before the magnetic paint or ink is dried.

The magnetic thin film layer 4 is provided for forming fixed information and performing a function of preventing forgery, and also performing a function of a print recording layer by a discharge printing method. As a material for forming the magnetic thin film layer, the coercive force needs to be 1000 Oe or less, for example, a magnetic metal such as Ni, Co, and Fe; a sendust alloy which is an Fe-Al-Si alloy;
Alloys such as Fe-Al-based alloys, Fe-Si-based alloys, Fe-Ni-based permalloys, Ni-Fe-Mo-based supermalloys, transition metal and transition metal-metalloid amorphous alloys, magnetic properties such as gamma iron oxide and barium ferrite Soft magnetic ferrites such as metal compounds, Zn ferrite, and Mn / Zn ferrite are applied to the present invention. These materials are used to form a magnetic thin film layer using a vapor deposition method, a sputtering method or a plating method. When the coercive force is 1000 Oe or more, it is difficult to concentrate the material constituting the magnetic thin film layer on the magnetic flux reversal interface of the magnetic recording performed on the magnetic recording layer, and it is difficult to form fixed information. .

In the magnetic recording medium of the present invention, it is preferable that an adhesion auxiliary layer 3 is provided between the magnetic recording layer 2 and the magnetic thin film layer 4. The adhesion auxiliary layer 3 is provided between the magnetic recording layer and the magnetic thin film layer to improve the adhesive strength between the two, and also functions to promote the destruction of the magnetic thin film layer 4 during discharge recording and to improve print recording characteristics. have. Examples of the material include acrylic resins such as polystyrene and polymethyl methacrylate (PMMA), and cellulose acetate propionate (C
A thermoplastic resin such as a cellulose resin such as AP), a vinyl chloride-vinyl acetate copolymer resin, a polyester resin, an epoxy resin, and a urethane resin is used. Further, in order to control the thermoplasticity of the thermoplastic resin, additives such as a plasticizer, a wax, and an inorganic pigment may be added to the adhesion auxiliary layer. When the magnetic thin film layer is not used as the discharge print recording layer, a thermosetting resin, for example, a polyester resin, a polyisocyanate-based curing agent, and a two-liquid mixed type resin may be used for the adhesion auxiliary layer. Further, a photocurable resin or an electron beam curable resin made of an acrylic oligomer can be used. When the adhesion between the magnetic recording layer and the magnetic thin film layer is sufficient, it is not necessary to provide an adhesion auxiliary layer. Further, as the protective layer 5 provided as needed, a resin such as a cellulose-based, polyester-based, urethane-based, epoxy-based, or acrylic-based resin can be used. These resins may be used alone or in combination of two or more, or may be used in combination with a curing agent such as an isocyanate-based curing agent. Also acrylic,
An ultraviolet curable resin or an electron beam curable resin made of polyester, epoxy, phosphazene or the like may be used. Waxes, inorganic pigments, or silicon-based or fluorine-based compounds may be added to these resin systems alone or in combination to enhance discharge recording characteristics.

The manufacturing method of the present invention will be described in more detail. For example, as shown in FIG. 2, the substrate 1 made of a non-magnetic material is sent out from a sending reel 11 and guided to a coating device 12 for coating a magnetic recording layer. Apply. Coating head 1
The substrate 1 coated in 3 is wound on a take-up reel 18 via a magnetic field orientation device 15, a drying part 16 and a roll 17 via a roll 14. The roll wound up is a raw material coated with only the magnetic recording layer. Next, an adhesion auxiliary layer is applied to the surface of the magnetic recording layer. The application method is the same as that for the magnetic recording layer described above. At this time, a recording magnetic head is mounted at the position 19 of the coating apparatus, and magnetic recording is performed on the magnetic recording layer. Recording may be performed in the same manner as recording on a magnetic recording medium using a normal magnetic recording device. When the adhesion between the magnetic recording layer and the magnetic thin film layer is sufficient, it is not necessary to provide an adhesion auxiliary layer. In this case, magnetic recording may be performed using a magnetic recording device as shown in FIG. In any case, the situation of the magnetic recording will be described with reference to FIGS. That is, the magnetic raw material 22 having the magnetic recording layer 2 is sent out from the magnetic raw material roll 23 and magnetized by the magnetic head 21 composed of electromagnets connected to a plurality of drive circuits (not shown), and is fixed for forgery prevention. Record the magnetic information that is the source of the information. Reference numeral 25 denotes a magnetic recording track, and the magnetic source 22 is wound around a magnetic-recorded source roll 24. The same reference numerals in each drawing indicate the same parts. In the magnetic recording track 25, a magnetic flux reversal interface 31 is formed in the magnetic recording section 26 as shown in the sectional view 5. Subsequently, a magnetic thin film layer is formed on the magnetic recording layer on which the magnetic recording has been performed, with or without an adhesion auxiliary layer. The magnetic thin film layer is formed by a method such as an evaporation method, a sputtering method, and a plating method. Then, the material constituting the magnetic thin film layer is deposited thickly on the magnetic flux reversal interface 31 as shown in FIG. 6, and the fixed information pattern 32 is formed.

In the above method, the magnetic substance mixed in the magnetic recording layer has the same coercive force as a normal magnetic recording medium of 200 to 5000 Oe.
After the formation of the magnetic recording layer, magnetic recording can be easily performed with a magnetic recording head. In this case, if the magnetic material is less than 250 Oersted, there is a problem that the magnetic material is erased by an external magnetic field for magnetic recording. On the other hand, if the magnetic material is larger than 5000 Oersted, magnetic recording of a magnetic head currently in practical use becomes impossible. When forming the magnetic thin film layer 4, first, magnetic recording is performed on the magnetic recording layer formed first. Recording may be performed at a predetermined recording density using a recording magnetic head as in the case of ordinary magnetic recording. As an example, magnetic recording is performed as follows. Using a digital FM recording method, a pulse current capable of sufficiently saturation recording on a magnetic recording layer is applied to a recording magnetic head. As the recording information, it is sufficient to record information desired to be stored in each recording medium (for example, one magnetic card) as a final product. That is, different recording media may record different, for example, serial number-like information or random fingerprint-like information, or recognition information for each manufacturing lot,
Unified information such as a manufacturer code may be used. These may be combined.

As described above, the magnetic thin film layer 4 is formed by using a sputtering method, a vapor deposition method, or a plating method. The material constituting the magnetic thin film layer is concentrated on the magnetic recording pattern previously applied to the magnetic recording layer and concentrated on the strong magnetic field at the interface of the magnetic field reversal part, and a pattern corresponding to the magnetic recording pattern is formed on the magnetic thin film layer Is fixed. The pattern formed on the magnetic thin film layer is magnetically readable even after erasing the magnetic recording information provided on the magnetic recording layer. For example, if reading is performed with a magnetic head while applying a DC bias magnetic field, an output corresponding to the pattern can be obtained.
If the coercive force of the magnetic thin film layer is 20 Oe or less,
Even after the fixed information is read by the magnetic head while applying a bias magnetic field, the pattern portion is not magnetized,
Since the presence of the pattern cannot be confirmed by observation with a magnetic viewer or the like, it is more preferable to use it for preventing unauthorized use.

The pattern-like fixed information formed on the magnetic thin film layer is formed corresponding to the magnetically recorded information on the magnetic recording layer. Therefore, when changing the fixed information, it is sufficient to change the magnetic recording information performed on the magnetic recording layer in the manufacturing process, and the change can be easily made. When fixed information such as a magnetic barcode is formed using a printing method or the like, a new plate must be created each time the fixed information is changed, but this method is not necessary in this method.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments. In addition, the number of parts represented by the material composition is all parts by weight. After the mixture prepared in the following composition was dispersed in a ball mill for 8 hours, 5 parts of a polyisocyanate curing agent was added,
The dispersion was further performed for one hour to obtain a paint for a magnetic recording layer. The coating material was applied to one surface of a base made of a white polyester film having a thickness of 188 μm using a reverse roll coater so that the coating thickness after drying was 12 μm to form a magnetic recording layer. At this time, the magnetic recording layer was subjected to a magnetic field alignment treatment using a magnetic field alignment apparatus before drying. Barium ferrite (coercive force 2750 Oersted, specific surface area 7 m ² / g) 100 parts Carbon black 3 parts Lecithin 1 part Vinyl chloride / vinyl acetate / vinyl alcohol copolymer 20 parts Polyurethane resin 20 parts Toluene 60 parts Methyl ethyl ketone 60 parts Methyl isobutyl ketone 60 parts

Magnetic recording was performed on the magnetic recording layer thus obtained using a magnetic head. A magnetic head having a head gap of 50 μm was used, and recording was performed with a recording current capable of sufficiently recording a magnetic recording layer. The recording method used was the FM method, and the recording density was 250 bpi.
Then, a coating for an adhesion auxiliary layer prepared with the following composition was applied to the surface of the magnetic recording layer by a reverse roll coater so that the coating thickness after drying was 2 μm. 100 parts of an aqueous polyolefin resin fine powder silica 5 parts of trimethylolpropane-tri-beta-A di lysine sulfonyl propionate 1 parts Isopropyl alcohol 15 parts Water 25 parts

Subsequently, Ni was deposited on the surface of the adhesion auxiliary layer by a vacuum deposition method to form a magnetic thin film layer. The film thickness was adjusted to be 600 ° as measured by a quartz oscillator. Further, a coating material for a protective layer prepared with the following composition was applied on the obtained magnetic thin film layer with a reverse roll coater to obtain a target material for a magnetic recording medium. Aqueous polyolefin resin 5 parts Fine powder silica 1 part Isopropyl alcohol 3 parts Water 20 parts The pattern to be fixed information is to form a metal thin film layer (in this case, a metal deposition layer) after performing magnetic recording on the magnetic recording layer Then, the material (in this case, Ni) constituting the metal thin film layer is formed by being concentrated on the magnetic flux reversal interface of magnetic recording. A JIS size magnetic card was punched out of the magnetic recording medium raw material thus obtained, and the following evaluation was performed.

That is, DC demagnetization was performed on the portion of the magnetic thin film layer where the fixed information was formed under the condition that the magnetic recording performed on the magnetic recording layer could be sufficiently erased. After that, the fixed information was read using a reproducing magnetic head while applying a bias magnetic field of 500 Gauss. As a result, the information corresponding to the fixed information pattern could be read. This information was not erased even after DC demagnetization was performed, and was fixed to the magnetic thin film layer as information independent of the magnetic recording layer. This information can be used as ID information of the magnetic card to prevent unauthorized use. Also, when a magnetic recording / reproducing apparatus for a card having a coercive force up to 3000 Oersted repeatedly performed normal magnetic recording, reproduction and erasing on a portion of the card where fixed information was not formed, no problem was found. Could be used. Further, when a character pattern such as a number and a kanji is printed on a portion of the card where fixed information is not formed by using a discharge recording device, it can be printed and recorded in the same manner as a normal discharge recording card. did it.

[0022]

As described above, in the magnetic recording medium of the present invention, magnetically detectable fixed information for preventing unauthorized use corresponding to the information recorded on the magnetic recording layer is formed on the magnetic thin film layer. . Further, the unauthorized use information can be ID information (fingerprint information) that differs depending on each magnetic recording medium product. Furthermore, the magnetic recording medium of the present invention has an unprecedented effect that it is possible to print and record by a discharge recording method on the magnetic thin film layer on which the fixed information is formed. Further, the method of manufacturing a magnetic recording medium of the present invention,
This is an application of the method used in the conventional method of manufacturing a magnetic recording medium and the magnetic recording itself, and does not require a special device, so that it is possible to easily manufacture a magnetic recording medium that is almost impossible to illegally use. Having.

[Brief description of the drawings]

FIG. 1A is a plan view of a magnetic recording medium of the present invention. FIG. 1B is a magnetic phase diagram after magnetization in a sectional view taken along line XX ′ of FIG.

FIG. 2 is a process diagram of a step of providing a magnetic recording layer.

FIG. 3 is a schematic diagram of a magnetic recording device.

FIG. 4 is a plan view showing the state of magnetic recording.

FIG. 5 is a sectional view near the magnetic reversal interface.

FIG. 6 is a diagram showing a state in which magnetic thin film layers and fixed information are formed.

[Explanation of symbols]

T track P magnetic flux reversal interface 1 base made of non-magnetic material 2 magnetic recording layer 3 adhesion auxiliary layer 4 magnetic thin film layer 5 protective layer 11 delivery reel 12 paint coating device 13 coating head 14 roll 15 magnetic field orientation device 16 drying part REFERENCE SIGNS LIST 17 roll 18 take-up reel 21 magnetic head 22 magnetic source 23 magnetic source roll 24 magnetic-recorded magnetic source roll 25 magnetic recording track 26 magnetic recording part 31 magnetic flux reversal interface 32 fixed information pattern

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-244598 (JP, A) JP-A-6-20264 (JP, A) Japanese Utility Model Application Sho 61-178586 (JP, U)

Claims (3)

(57) [Claims] A magnetic recording layer made of a magnetic material having a coercive force of 200 to 5000 Oe and a magnetic thin film layer made of a coercive force of 1000 Oe or less are sequentially laminated on a base made of a non-magnetic material. Patterns that are thicker than other parts of the layer that cannot be added or erased later
A magnetic recording medium characterized in that the fixed information is formed. 2. A method for manufacturing a magnetic recording medium according to claim 1, wherein a magnetic paint having a coercive force of 200 to 5000 Oe is applied to a nonmagnetic substrate and dried to form a magnetic recording layer. By performing magnetic recording, and then forming a magnetic thin film layer on the magnetic recording layer by at least one method selected from a vapor deposition method, a sputtering method, and a plating method, so that the magnetic thin film layer cannot be added or erased later. A method for manufacturing a magnetic recording medium, comprising forming information on the magnetic thin film layer. 3. A magnetic recording medium according to claim 1, wherein the magnetic thin film layer of the magnetic recording medium according to claim 1 is provided with print recording by a discharge breakdown method.