JPH06338050A - Magnetic recording medium and manufacturing method thereof - Google Patents

Abstract

PURPOSE:To prevent unauthorized use by forming a discontinuous pattern by a required system in a thin magnetic layer disposed on a magnetic recording layer and using this pattern as unauthorized use preventing information. CONSTITUTION:A magnetic layer 2 of a magnetic substance having 200-5,000 Oe coercive force, an adhesion assisting layer 3, a thin magnetic layer 4 and a protective layer 5 are laminated on a nonmagnetic substrate 1. The layers 4, 5 are then destructed by irradiation at a high temp. of >=300 deg.C to form a discontinuous pattern 7 of ID information. This ID information is made difficult to erase or rewrite and the objective magnetic recording medium capable of easily and satisfactorily preventing unauthorized use is produced.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a magnetic card such as a shopping card, a savings card, a commuter pass, a ticket, a coupon, a prepaid card, a cash card, a credit card, an identification card, a medical examination card, a magnetic sheet, a magnetic sheet. The present invention relates to a magnetic recording medium used for roll paper and the like and a method for manufacturing the same.

[0002]

2. Description of the Related Art Recently, magnetic recording cards or magnetic recording media such as magnetic roll paper have been widely used. The basic structure is that a magnetic layer is provided on a non-magnetic substrate and magnetized. In such a magnetic recording medium, it is necessary to prevent illegal use due to duplication or falsification of magnetic information, and therefore various illegal use preventing measures have been taken. Typical methods for preventing unauthorized use are roughly classified into a method of making it difficult to record and reproduce magnetic recording information and a method of providing the magnetic recording medium itself with authenticity determination information. The former is a method that hides the recorded legitimate magnetic information and makes it difficult to tamper with or duplicate the magnetic information by making it difficult to write or read the information. This is a method of preventing forgery and alteration by inserting identification information for determining whether or not the magnetic card itself.

[0003]

More specifically, the former known measure for preventing unauthorized use by making it difficult to record / reproduce magnetic recording information has a multilayer magnetic recording layer. This makes it impossible to read the legitimate information by making it unreadable or superimposing dummy information to make it difficult to analyze the legitimate information.However, if the legitimate information and the dummy information are recorded on the same track, the Since the dummy information is sometimes superimposed on the legitimate information, the legitimate information cannot be read by a normal method. However, there are drawbacks such as a complicated recording and reading device, and
Once the details of the method for reading the legitimate information are known, a person who is familiar with magnetic recording can read and analyze the information, which causes a problem that a large number of magnetic recording media can be duplicated. Have. On the other hand, the latter magnetic recording medium is, for example, a magnetic card in which authenticity determination information is applied to the magnetic card itself, a magnetically readable bar code is provided, and the authenticity of the information is determined by the bar code information. However, it is difficult to duplicate a large amount of medium and illegally use it because the medium itself has the information for determining whether the magnetic recording medium is legitimate, but rewriting the information on the legitimate medium, etc. Unauthorized use of can not be dealt with.

[0004]

The magnetic recording medium according to the present invention has been made to solve the problems of the prior art described above, and is characterized in that a magnetic thin film layer is formed on the magnetic recording layer. To do. According to the invention of claim 1, 200 oersteds to 500 are provided on a substrate made of a non-magnetic material.
A magnetic recording medium is characterized in that a magnetic recording layer and a magnetic thin film layer made of a magnetic material having a coercive force of 0 Oersted are sequentially laminated, and a patterned discontinuous portion is formed in the magnetic thin film layer. According to the second aspect of the present invention, in manufacturing the magnetic recording medium according to the first aspect, a magnetic paint or a magnetic ink made of a magnetic substance having a coercive force of 200 Oersted to 5000 Oersted is applied or coated on a substrate made of a non-magnetic substance. After printing and drying to form a magnetic recording layer, a magnetic thin film layer is laminated on the magnetic recording layer by at least one method selected from vapor deposition, sputtering, and plating, and then the magnetic thin film layer is formed. A method of manufacturing a magnetic recording medium, characterized in that a pattern-shaped discontinuous portion is formed by an electric discharge recording method.

The present invention will be described in more detail below. In the magnetic recording medium according to the present invention, a magnetic recording layer is provided on a substrate made of a non-magnetic material, and a magnetic thin film layer is further laminated on the magnetic recording layer. In a magnetic recording medium in which a pattern-shaped discontinuous portion is formed in a thin film layer and used as information (fixed information) for preventing unauthorized use, the fixed information portion is formed in a bar code pattern, for example. The fixed information portion is formed by breaking the magnetic thin film layer into a pattern by the discharge recording method.

As a means for destroying the magnetic thin film layer, there is a method of melting by a thermal recording system using a thermal head system, a laser system or the like. The magnetic thin film layer has a melting point of 300.
Higher than ℃, it cannot be easily melted. When the electric discharge recording method is used, the magnetic thin film layer is easily destroyed by heat and electric energy generated by electric discharge, and a discontinuous portion can be formed.

Since the pattern-shaped discontinuous portion formed in the magnetic thin film layer is formed by the discharge recording method, in the final magnetic recording medium, for example, when issuing a magnetic card, each card is It is possible to give different ID information to each. This ID information is for card 1
It can be used as fingerprint information for each sheet, and is optimal information for preventing forgery of cards. Further, since the discharge recording method is used, it is possible to dramatically increase the amount of information as compared with the conventional unauthorized use prevention information. In addition, a pattern-shaped discontinuous portion is additionally formed by a discharge recording method according to the usage status of the magnetic recording medium, whereby the usage history of the medium can be recorded. Since the use history forms a discontinuous portion by destroying the magnetic thin film layer and serves as recorded information, it is impossible to erase the recorded information afterwards. That is, for example, if the usage history of a magnetic card is recorded by this method, it is possible to prevent the card once used from being altered and used.

According to the present invention, information that can be added but cannot be erased, that is, write-once information, can be added to a magnetic recording medium as high density and complicated information, and it is possible to prevent unauthorized use of the magnetic recording medium. It is possible to provide the optimum method. On the other hand, it goes without saying that normal printing and recording of characters, numbers, figures, etc. can be performed by a discharge recording method in a portion other than the range where the unauthorized use prevention information is provided. Further, in the present invention, since the layer formed on the magnetic recording layer is a magnetic thin film layer and is very thin, it has almost no adverse effect on normal magnetic recording performed on a portion other than the range where the unauthorized use prevention information is provided. Never.

The present invention will be described below with reference to the drawings.
FIG. 1 is a plan view of a magnetic card which is a magnetic recording medium according to the present invention. FIG. 2 is a cross-sectional view taken along line XX ′ of FIG. 1, in which a magnetic recording layer 2, an adhesion auxiliary layer 3, and a magnetic layer 2 made of a magnetic material having a coercive force of 200 Oersted to 5000 Oersted are formed on a substrate 1 made of a nonmagnetic layer. The thin film layer 4 and the protective layer 5 are formed. A printed layer of letters, numbers, figures, etc. may be provided on the protective layer 5. The above-mentioned adhesion auxiliary layer 3 is provided between the magnetic recording layer 2 and the magnetic thin film layer 4 so as to improve the adhesive force between them and the discharge recording sensitivity when destroying the magnetic thin film layer by the discharge recording method. It also plays a role in improving. The protective layer 5 is intended to enhance the discharge recording characteristics and the environmental resistance characteristics of the magnetic recording medium of the present invention. The adhesion auxiliary layer 3 and the protective layer 5 may be omitted in some cases.

Reference numeral 6 in FIG. 1 is visible information consisting of characters, numbers, figures, etc. printed by the discharge recording method in a portion other than the range for providing the unauthorized use prevention information. As the visible information, for example, when the magnetic recording medium is a magnetic card such as a prepaid card, it is used to display the date of use, the balance, and the like. Reference numeral 7 in FIG. 1 denotes a pattern-like discontinuous portion as unauthorized use prevention information, which is formed by destroying the magnetic thin film layer by an electric discharge recording method. Reference numeral 8 in FIG. 2 is a cross section of this pattern-shaped discontinuous portion, and the magnetic thin film layer is eliminated in the pattern portion, and the discontinuous portion is formed in the magnetic thin film layer. This portion can be detected magnetically, for example, by a magnetic head while applying a DC bias magnetic field.

Next, materials constituting the magnetic recording medium of the present invention will be described. First of all, as the base made of non-magnetic material,
A sheet-shaped non-magnetic material such as a polyester film having a thickness of 150 μm to 1 mm, a vinyl chloride film, a synthetic paper, a wood pulp paper, a laminated paper, a metal sheet, or a ceramic such as glass can be applied. The magnetic substance used for the magnetic recording layer 2 laminated adjacent to the substrate 1 has a coercive force of 2
00-5000 Oersted ferromagnet, for example, γ-
Fine powders of iron oxide, cobalt-doped γ-iron oxide, chromium oxide, barium ferrite, strontium ferrite and the like are applied. In this case, if it is less than 200 Oersted, it is difficult to maintain the magnetic recording, while 500
When it exceeds 0 Oersted, magnetic recording cannot be stably performed by a normal magnetic head. Vinyl chloride
Disperse with a binder such as vinyl acetate vinyl acetate, vinyl chloride / vinyl acetate / vinyl alcohol copolymer, polyurethane resin, polyester resin, epoxy resin, etc., alone or in combination with additives such as pigments other than magnetic materials. A magnetic paint or ink, which is applied or printed on the substrate 1,
The magnetic recording layer 2 can be formed by drying. A hardener such as an isocyanate hardener may be used in combination with the magnetic paint. The magnetic recording layer 2 may be subjected to a magnetic field orientation treatment before the magnetic paint or ink is dried.

Examples of the material of the adhesion auxiliary layer include polystyrene, acrylic resins such as polymethylmethacrylate (PMMA), and cellulose acetate propionate (C).
Cellulosic resins such as AP), vinyl chloride-vinyl acetate copolymer resins, thermoplastic resins such as polyester resins, epoxy resins and urethane resins, photo-curable resins, electron beam curable resins are used. Further, in order to control the thermoplasticity of the thermoplastic resin, additives such as a plasticizer, wax and inorganic pigment may be added to the adhesion auxiliary layer.

Materials for forming the magnetic thin film layer include, for example, magnetic metals such as Ni, Co and Fe, Sendust alloys which are Fe-Al-Si alloys, Fe-Al alloys and Fe- alloys.
Si-based alloy, Fe-Ni-based permalloy, Ni-Fe-M
Alloys such as o-based supermalloys, transition metals and transition metals-
Amorphous metalloid alloy, γ-iron oxide, magnetic metal compounds such as barium ferrite, Zn ferrite, Mn
-Soft magnetic ferrite such as Zn ferrite is applied to the present invention. When selecting these magnetic materials, a magnetic material having a smaller coercive force than that of the magnetic recording layer is preferable for the present invention. Particularly preferably, it is 20 oersted or less. When the coercive force of the magnetic thin film layer is larger than that of the magnetic recording layer,
In normal magnetic recording performed on the magnetic recording layer, when recording, erasing, and overwriting are repeated,
This causes problems such as the loss of information. If the coercive force is 20 oersted or less, the above condition is always satisfied, and the pattern portion is not magnetized even after reading with the magnetic head while applying the DC bias magnetic field. Since it is not possible to confirm the existence of the pattern by observation, it is more preferable for the purpose of preventing unauthorized use.

Further, as the protective layer 5 which is provided as required, cellulose-based, polyester-based, urethane-based, epoxy-based, acrylic-based resins or the like can be used. These resins can be used alone or in combination. It may be used, or may be used in combination with a curing agent such as an isocyanate curing agent. Further, an ultraviolet curable resin or an electron beam curable resin made of an acrylic resin, a polyester resin, an epoxy resin, a phosphazene resin, or the like may be used, and a wax or an inorganic pigment or a resin may be used in these resin systems in order to enhance discharge recording characteristics. Silicon type,
Fluorine compounds may be added alone or in combination.

Regarding the step of providing the magnetic recording layer on the substrate by the coating method of the magnetic paint in the manufacturing method of the present invention,
More detailed description is as shown in FIG. That is, the substrate 1 made of a non-magnetic material is delivered from the delivery reel 11 and guided to the coating device 12 for coating the coating material for the magnetic recording layer for coating. The substrate 1 applied by the coating head 13 passes through the roll 14, the magnetic field orientation device 15, the drying part 16, and the roll 17, and is then wound around the winding reel 18. The wound roll is a raw material coated with only the magnetic recording layer.
Although not shown in the drawings for forming the magnetic recording layer by a printing method, a similar original sheet can be formed by a screen printing method, a gravure printing method, an offset printing method, or the like.

[0016]

EXAMPLES The present invention will be described in detail below based on examples. In addition, all parts represented by the material composition are parts by weight. After the mixture prepared by the following composition was dispersed by a ball mill for 8 hours, 5 parts of a polyisocyanate curing agent was added,
Further, dispersion was carried out for 1 hour to obtain a magnetic coating material for magnetic recording layer. The coating material was applied by a reverse roll coater to one side of a substrate made of a white polyester film having a thickness of 188 μm 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 orientation treatment by a magnetic field orientation device before being dried. 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 copies

Next, the coating thickness for the adhesion auxiliary layer prepared by the following composition on the surface of the magnetic recording layer is 2 after drying.
It was applied with a reverse roll coater so as to have a thickness of μm. Aqueous polyolefin resin 100 parts Fine powder silica 5 parts Trimethylolpropane tri-β-azirinyl propionate 1 part 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 600Å as measured by a crystal oscillator. Further, a coating material for a protective layer prepared by the following composition was applied on the obtained magnetic thin film layer by a reverse roll coater to obtain a desired raw material for a magnetic recording medium. Aqueous polyolefin resin 5 parts Fine powder silica 1 part Isopropyl alcohol 3 parts Water 20 parts A magnetic card of JIS size is punched out from the magnetic recording medium stock thus obtained to obtain a magnetic card, which is subsequently discharged to the card. A bar code pattern shown in 7 of FIG. 1 was printed using a recording device to form a discontinuous portion, and a magnetic recording medium of the present invention was obtained.

Next, the following evaluation was performed on the obtained magnetic recording medium. That is, when a magnetic head was used to read information while applying a bias magnetic field of 500 Gauss to a bar code pattern discontinuous portion formed on the magnetic thin film layer by electric discharge recording, a fixed information pattern was obtained. The pulse signal could be read out. Moreover, when a magnetic recording / reproducing apparatus for a card having a coercive force of up to 3000 Oersted on the same track was used for normal magnetic recording, reproduction and erasing, it could be used without any problem. Furthermore, 500
When information was read from the barcode pattern while applying a Gaussian bias magnetic field, the information by the barcode pattern was not erased even after direct current demagnetization on the track with the barcode pattern. It could be read as information independent of the magnetic recording layer. This information could be used as magnetic card ID information to prevent unauthorized use. Moreover, when magnetic recording / reproducing apparatus for a card having a coercive force of up to 3000 Oersted was used to repeat normal magnetic recording, reproduction, and erasing in a portion of this card where fixed information was not formed, no problem was found. I was able to use it. Furthermore, when a character pattern such as numbers and Chinese characters was printed on the part of this card where the fixed information was not formed using an electric discharge recording device, it could be printed and recorded in the same manner as a normal electric discharge recording card. did it.

[0020]

As described above, the magnetic recording medium of the present invention is
It has magnetically detectable fixed information for preventing unauthorized use by a simple method of forming a magnetic thin film layer on the magnetic recording layer and forming a pattern-shaped discontinuous portion on the magnetic thin film layer by a discharge recording method. . Further, the illegal use can be made different ID information (fingerprint information) depending on individual magnetic recording medium products. Furthermore, the magnetic recording medium of the present invention has an unprecedented function and effect that it is possible to print and record on the magnetic thin film layer on which the fixed information is formed by the discharge recording method. The method of manufacturing a magnetic recording medium of the present invention applies 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, and thus is almost free from unauthorized use. It has an effect that a possible magnetic recording medium can be easily manufactured.

[Brief description of drawings]

FIG. 1 is a plan view of a magnetic recording medium of the present invention.

FIG. 2 is a state diagram of magnetism after magnetization in a cross-sectional view taken along line XX ′ of FIG.

FIG. 3 is a process diagram of a step of providing a magnetic recording layer

[Explanation of symbols]

 1 Substrate made of non-magnetic material 2 Magnetic recording layer 3 Adhesion auxiliary layer 4 Magnetic thin film layer 5 Protective layer 6 Visible information 7 Patterned discontinuous portion 8 Cross section of patterned discontinuous portion 11 Delivery reel 12 Paint coating device 13 Coating head 14 Roll 15 Magnetic field orienting device 16 Drying part 17 Roll 18 Take-up reel

Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location G11B 5/84 Z 7303-5D

Claims (2)

[Claims] 1. A magnetic recording layer and a magnetic thin film layer made of a magnetic substance having a coercive force of 200 Oersted to 5000 Oersted are sequentially laminated on a substrate made of a non-magnetic substance, and the magnetic thin film layer is discontinuous in a pattern. A magnetic recording medium having a portion formed. 2. In manufacturing the magnetic recording medium according to claim 1, a magnetic paint or a magnetic ink made of a magnetic material having a coercive force of 200 Oersted to 5000 Oersted is applied on a substrate made of a non-magnetic material or dried after printing. After forming the magnetic recording layer, 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, and a discharge recording method is applied to the magnetic thin film layer. A method of manufacturing a magnetic recording medium, characterized in that a pattern-shaped discontinuous portion is formed by the method.