JPH0930163A - Magnetically printed matter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To minimize the influence caused by a change in a machine environment and thereby enable data on a printed matter to be stably read by adding a flat magnetic material with a specific low coercive force, in a magnetically printed matter formed by printing an ink containing the magnetic material. SOLUTION: A magnetically recording medium 1 consists of a base 11, a magnetically recording layer 12 and a magnetically printed matter 2, and has a print layer 13 formed in such a state that both magnetically printed matter 2 and magnetically recording layer 12 are covered by the print layer 13. This magnetically printed matter 2 is formed by printing an ink containing a magnetic material with low coercive force, and the magnetic material with low coercive force to be used is a magnetic alloy material or a metallic material with high permeability, and the coercive force is 20Oe or less. In addition, the magnetic material is flat, and the degree of the flatness is about 5-200 in terms of the aspect ratio of length to thickness, and preferably is about 50-100. The magnetically printed matter 2 has the amount of variation in a magnetic output to a bias current variation, of 10-40%.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a magnetic printed matter,
In particular, the present invention relates to a magnetic printed material that is formed on a substrate or the like and that generates a stable magnetic output without being affected by the mechanical environment.

[0002]

2. Description of the Related Art As a medium having a magnetic recording layer, for example, prepaid cards, commuter tickets, boarding tickets, admission tickets, car tickets, betting tickets, gift certificates, stock certificates, certificates, passbooks, magnetic tags, etc. Various media such as cards, ID cards, cash cards, credit cards, membership cards, and magnetic labels are widely used. In such a medium, a bar code is formed by magnetic printing as a countermeasure against forgery. For example, a magnetic material having a coercive force lower than that of the magnetic material forming the magnetic recording layer is used. Method for forming bar code on top (JP-A-61-161)
77137). In reading a bar code formed using such a magnetic material having a low coercive force, a magnetic field is generated by a bias current, the bar code is magnetized corresponding to the magnetic field strength, and the magnetic output is read by a magnetic head. It is a thing.

[0003]

However, the conventional bar code magnetic printed matter is affected by a change in bias current value (change in magnetic field strength) and an external magnetic field, or an influence of a gap loss due to the thickness of the magnetic printed matter. There is a problem that the magnetic output changes greatly and stable reading cannot be performed.

The present invention has been made in view of the above circumstances, and is a magnetic printed matter whose magnetic output is read after being magnetized by a magnetic field generated by a bias current, and which is affected by changes in the mechanical environment or the like. It is an object of the present invention to provide a magnetic printed material having a very small amount.

[0005]

In order to achieve such an object, the present invention provides a magnetic printed material formed by printing an ink containing a magnetic material, containing a magnetic material having a flat shape and a low coercive force. It was configured to do.

In the present invention, the coercive force of the magnetic material is 2
The structure was such that it was 0 Oe or less, the structure in which the aspect ratio of the magnetic material was in the range of 5 to 200, and the structure in which the magnetic output change amount with respect to the change in bias current was in the range of 10 to 40%.

Since the magnetic printed material of the present invention contains a magnetic material having a low coercive force as the magnetic material, the magnetic printed material is magnetized by the magnetic field generated by the bias current, and the magnetic output can be read by the magnetic head. Moreover, since the above-mentioned magnetic material is magnetically anisotropic due to its flat shape, the magnetic printed matter has a characteristic that the magnetic output is saturated at a certain magnetic field strength or more, and therefore is generated by the bias current. The magnetic output changes very little even if the magnetic field strength changes and the magnetic flux density changes.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a plan view showing an example of a magnetic recording medium provided with the magnetic printed material of the present invention, and FIG. 2 is a longitudinal sectional view taken along line XX of the magnetic recording medium shown in FIG. 1 and 2, the magnetic recording medium 1 includes a substrate 11
And a magnetic recording layer 12 provided on the base 11, and a magnetic printed material 2 formed in a desired pattern on a predetermined portion of the magnetic recording layer 12. The magnetic printed material 2 and the magnetic recording layer 1 are provided.
The print layer 13 is formed so as to cover 2 and 2.

The magnetic printed material 2 of the present invention contained in the above magnetic recording medium 1 is formed by printing an ink containing a low coercive force magnetic material.

As a magnetic material having a low coercive force, Al or S is used.
Examples thereof include magnetic alloy materials made of i, Fe and the like, metal high magnetic permeability materials such as permalloy and sendust, ferrites such as Mn-Zn ferrite, and metal amorphous materials. A magnetic material having a coercive force of 20 Oe or less is used. It is preferable.

Further, the present invention is characterized in that the above magnetic material has a flat shape. This is because the conventional magnetic printed matter that uses a magnetic material having a spherical shape and magnetically isotropic property has a magnetic field corresponding to the magnetic flux density due to the change in the magnetic field strength when the strength of the magnetic field generated by the bias current changes. We found that the magnetic output saturates at a constant value, even if the magnetic field strength changes, by using a magnetic material that is flat and has magnetic anisotropy, while the output changes. by. The flat shape of the magnetic material used in the present invention may be a circular flat plate shape, an elliptic flat plate shape, a polygonal flat plate shape, a needle shape, etc., and the flatness degree is about 5 to 200 in terms of the aspect ratio of length and thickness, preferably Can be about 50-100.

The magnetic printed material of the present invention uses an ink obtained by dispersing fine particles of the flat magnetic material as described above in a resin or an ink vehicle, a gravure printing method, a silk printing method, an offset printing method, a letterpress printing method. It can be formed according to a known printing method such as a printing method and has a thickness of 2 to 20.
About μm is preferable.

The resin or ink vehicle in which the above magnetic material is dispersed includes butyral resin, vinyl chloride / vinyl acetate copolymer resin, urethane resin, polyester resin, cellulose resin, acrylic resin, styrene / maleic acid copolymer resin. Etc. are used, and rubber-based resin such as nitrile rubber or urethane elastomer is added if necessary. Further, a resin having a high glass transition temperature (Tg) such as polyamide, polyimide or polyether sulfone, or a system in which Tg is increased by a curing reaction may be used. If necessary, a pigment such as a surfactant, a silane coupling agent, a plasticizer, a wax, a silicone oil, or carbon is added to the ink in which the magnetic fine particles are dispersed in the resin or the ink vehicle as described above. You may.

The substrate 11 constituting the magnetic recording medium 1 can be appropriately selected from various substrates conventionally used for cards and the like in consideration of the required heat resistance, strength, rigidity and the like, For example, materials appropriately selected from materials such as nylon, cellulose diacetate, cellulose triacetate, vinyl chloride, polystyrene, polyethylene, polypropylene, polyester, polyimide, polycarbonate, etc., metals such as copper and aluminum, paper, impregnated paper, etc. Can be used alone or in combination. The thickness of such a base 11 can be set to about 0.005 mm to 5 mm.

As the magnetic material forming the magnetic recording layer 12, a magnetic material having a coercive force in the range of 250 to 3000 Oe, for example, γ-Fe ₂ O ₃ and Co deposited γ-.
_{Fe 2 O 3, Fe 3 O} 4, Fe, Fe-Cr, Fe-C
o, Co-Cr, Co- Ni, Ba ferrite, Sr ferrite, and a magnetic particle such as CrO _2. The magnetic recording layer 12 can be formed by applying a dispersion prepared by dispersing such magnetic fine particles in the above resin or ink vehicle according to a known coating method such as a gravure method, a roll method, a knife edge method or the like. it can. Also, F
The magnetic recording layer 12 can also be formed by using a metal or alloy such as e, Fe-Cr, Fe-Co, Co-Cr, or an oxide thereof, by a vacuum deposition method, a sputtering method, a plating method, or the like.

Further, the printing layer 13 constituting the magnetic recording medium 1 is composed of cellulose derivatives such as ethyl cellulose, cellulose nitrate, ethyl hydroxyethyl cellulose, cellulose acetate propionate and cellulose acetate, polystyrene and styrene such as poly-α-methylstyrene. Resin, styrene copolymer resin, acrylic resin such as polymethylmethacrylate, polyethylmethacrylate, ethylethylacrylate, polybutylacrylate, or methacrylic resin homopolymer or copolymer resin, rosin, rosin-modified maleic acid resin, rosin Modified phenol resin, rosin ester resin such as polymerized rosin, polyvinyl acetate resin,
Coumarone resin, vinyl toluene resin, vinyl chloride resin,
To the binder of polyester resin, polyurethane resin, butyral resin, etc., various pigments are added according to the color to be colored, and titanium oxide, alumina powder, micro silica, etc. are added so as to have the cleaning effect of the magnetic head if necessary. Add, and if necessary, plasticizer, stabilizer, wax, grease, desiccant, drying aid, curing agent, thickener, dispersant, and then sufficiently knead with solvent or diluent. It can be formed by using a coloring paint or ink of the following, by a coating method or a printing method such as a usual gravure method, a roll method, a knife edge method, and an offset method.

A magnetic print 2 of such a magnetic recording medium 1
Is magnetized by the magnetic field generated by the bias current flowing in the magnetizing head by using the magnetic head in which the magnetizing head and the read head are integrated, and the magnetic output can be measured by reading with the read head. Since it contains a flat shape low coercive force magnetic material having properties,
The magnetic output of the magnetic printed material 2 has a characteristic of being saturated at a constant value. Therefore, change in bias current value (change in magnetic field strength)
Stable reading is possible because the influence of external magnetic field, magnetic field, or gap loss due to the thickness of the magnetic printed material is extremely small.

As described above, in the magnetic printed material of the present invention, the magnetic output change amount with respect to the change of the bias current is 10 to 40%.
The range may be, preferably, 10 to 30%. Here, the above-mentioned magnetic output change amount can be calculated by relative arithmetic calculation as the incremental ratio of the magnetic output to the incremental ratio of the bias current value.

In the above-mentioned aspect, the magnetic printed material of the present invention is formed on a card-shaped magnetic recording medium.
It may be formed on a magnetic recording medium having another structure, a gold voucher, or the like, and there is no particular limitation on an object to be formed forming the magnetic printed material of the present invention.

Next, the present invention will be described in more detail with reference to specific examples. Example 1 A 188 μm thick opalescent polyester film was coated on one side with a coating solution for forming a magnetic recording layer having the following composition by a gravure reverse method to a thickness of 12 μm.
Magnetic recording layer was formed.

(Coating liquid for forming magnetic recording layer) Magnetic powder (coercive force = 2750 Oe) 37 parts by weight Vinyl chloride-vinyl acetate copolymer resin 10 parts by weight Toluene 21 parts by weight Methyl ethyl ketone 15 parts by weight Methyl isobutyl ketone ... 9 parts by weight Anon ... 7 parts by weight Next, a magnetic printing ink A having the following composition was printed on the above magnetic recording layer by a silk screen method to form a magnetic pattern having a predetermined pattern. A barcode (film thickness 7 μm) was formed.

(Ink A for magnetic printing) Iron-based amorphous alloy (soft magnetic powder) (coercive force = 15 Oe, aspect ratio = 30) 70 parts by weight Vinyl chloride-vinyl acetate copolymer resin 4 parts by weight Polyurethane resin: 4 parts by weight Organic bentonite: 0.4 parts by weight: Isophorone: 14.4 parts by weight: Butyl carbitol acetate: 7.2 parts by weight Further, the following is provided so as to cover the magnetic bar code and the magnetic recording layer. A printing layer was formed by a silk screen method using a printing ink having the composition.

(Printing ink) -Aluminum paste ... 20 parts by weight-Vinyl chloride-vinyl acetate copolymer resin ... 18 parts by weight-Cyclohexanone ... 31 parts by weight-Solvesso ... 31 parts by weight 86 mm x sheet prepared as above A magnetic recording medium having a magnetic printed material of the present invention as shown in FIG. 1 was obtained by punching out into a card having a size of 54 mm.

For the magnetic printed matter (magnetic bar code) of this magnetic recording medium, a measuring machine using a magnetic head in which a magnetizing head and a reading head are integrated (manufactured by San-Etec Co., Ltd. magnetic card evaluation machine EMMC-3). Was used to apply a magnetic field of various intensities while changing the bias current flowing through the magnetizing head, and the magnetic output of the magnetic print was measured. The result is shown by the curve A-1 in FIG. (Example 2) Further, a magnetic recording medium was prepared in the same manner as in Example 1 except that the thickness of the magnetic bar code was set to 10 µm, and the bias current was varied to apply magnetic fields of various intensities. The magnetic output of the magnetic print was measured. The result is shown by the curve A-2 in FIG. Comparative Example 1 On the other hand, as a comparison, a magnetic recording medium was produced in the same manner as in Example 1 except that the magnetic printing ink B was replaced with the magnetic printing ink B having the following composition. And Example 1
Similarly, the bias current was changed to apply a magnetic field of various strengths, and the magnetic output of the magnetic print was measured. The result is shown by the curve B-1 in FIG.

(Ink B for magnetic printing) Iron-based amorphous alloy (soft magnetic powder) (Coercive force = 15 Oe, aspect ratio = 1) 70 parts by weight Vinyl chloride-vinyl acetate copolymer resin 4 parts by weight Polyurethane resin: 4 parts by weight Organic bentonite: 0.4 parts by weight Isophorone: 14.4 parts by weight Butyl carbitol acetate: 7.2 parts by weight (Comparative example 2) The thickness of the magnetic bar code was set to 10 μm, etc. A magnetic recording medium was manufactured in the same manner as in Comparative Example 1 described above, the bias current was changed, magnetic fields of various intensities were applied, and the magnetic output of the magnetic printed material was measured. The result is shown in FIG.
Curve B-2.

As shown in FIG. 3, in the magnetic printed material of the present invention, when the magnetic field strength exceeds a predetermined value, the magnetic output saturates at a substantially constant value, and even if the magnetic field changes above the predetermined strength, the magnetic field is stable. The output was shown. Specifically, the magnetic output change amount with respect to the change of the bias current at 20 mA or more is 20
%, Which was extremely low. Further, almost no difference in magnetic output due to the difference in the film thickness of the magnetic bar code was confirmed, and it was confirmed that the magnetic printed material of the present invention is very little affected by the gap loss due to the thickness.

On the other hand, in the case of the comparative example, since the magnetic material contained in the magnetic printed material is not in a flat shape, when the strength of the magnetic field generated by the change of the bias current changes, the change of the magnetic field strength causes the change. A large change occurs in the magnetic output according to the magnetic flux density, and the magnetic output change amount is 60 with respect to the change in bias current at 20 mA or more.
% Or more, which is much larger than that of the present invention. Further, a relatively large difference was observed in the magnetic output due to the difference in the thickness of the magnetic bar code, and it was confirmed that the conventional magnetic printed matter was greatly affected by the gap loss due to the thickness.

[0029]

As described above in detail, according to the present invention, since the magnetic printed material contains the flat magnetic material having a low coercive force as the magnetic material, the magnetic printed material is magnetized by the magnetic field generated by the bias current. Although the printed matter is magnetized, the magnetic output of the magnetic printed matter of the present invention has a characteristic that the magnetic output is saturated at a constant value even if the bias current changes (change in magnetic field strength). The influence of the mechanical environment and the influence of the gap loss due to the thickness of the magnetic printed matter are extremely small, and the effect that the magnetic printed matter can be read stably can be obtained.

[Brief description of drawings]

FIG. 1 is a plan view showing an example of a magnetic recording medium provided with a magnetic printed material of the present invention.

FIG. 2 is a vertical sectional view taken along line XX of the magnetic recording medium shown in FIG.

FIG. 3 is a diagram showing a relationship between a bias current and a magnetic output in the magnetic printed material of the present invention and the conventional magnetic printed material.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Magnetic recording medium 2 ... Magnetic printed matter 11 ... Substrate 12 ... Magnetic recording layer 13 ... Printing layer

Claims (4)

[Claims] 1. A magnetic printed material formed by printing an ink containing a magnetic material, wherein the magnetic printed material contains a flat magnetic material having a low coercive force. 2. The magnetic printed material according to claim 1, wherein the magnetic material has a coercive force of 20 Oe or less. 3. The aspect ratio of the magnetic material is 5 to 2
The magnetic printed material according to claim 1 or 2, wherein the magnetic printed material is in a range of 00. 4. The magnetic printed matter according to claim 1, wherein the magnetic printed matter has a magnetic output change amount in a range of 10 to 40% with respect to a change in bias current.