JP3220808B2 - Thermal magnetic recording media - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermosensitive magnetic recording medium for recording visible information such as characters and patterns by a recording device such as a thermal head.

[0002]

2. Description of the Related Art Conventionally, as a magnetic recording medium in which a magnetic recording layer is provided on the surface of a substrate such as plastic,
Credit cards, cash cards, ID cards, tickets, commuter passes, magnetic tapes, etc. are widely used,
In recent years, in addition to the magnetic information of such a magnetic recording medium, for example, a medium capable of recording visible information has been developed as disclosed in Japanese Patent Application Laid-Open No. 60-18388. As such a magnetic recording medium, a thermosensitive magnetic recording medium in which a magnetic recording layer is provided on a base and a metal thin film layer is provided on the magnetic recording layer as a thermosensitive recording layer is known.

[0003]

In the above-described conventional thermosensitive magnetic recording medium, the metal thin film layer of the thermosensitive magnetic recording medium is destroyed mainly at the periphery of the thermosensitive magnetic recording medium due to a discharge phenomenon due to static electricity. . As a result, since the color of the lower magnetic recording layer is exposed, there is a problem that the commercial value of the thermosensitive magnetic recording medium is reduced.

[0004] Therefore, an object of the present invention is to provide a thermosensitive magnetic recording medium having high quality maintaining ability and durability.

[0005]

SUMMARY OF THE INVENTION The present invention has found a structure in which a concealing layer mainly composed of a pigment and a binder is formed on a peripheral portion of a metal thin film layer on which visible information of a thermosensitive magnetic recording medium having remarkable destruction is recorded. This is to solve the above-mentioned problem.

[0006]

By providing a concealing layer mainly composed of a pigment and a binder on the periphery of the metal thin film layer on which visible information of the thermosensitive magnetic recording medium is recorded, even if the metal thin film layer is destroyed by an electrostatic discharge phenomenon. Since the concealing layer is not destroyed by static electricity, it has the effect of preventing the color of the underlying magnetic recording layer from being exposed.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 1 is a front view of a thermosensitive magnetic recording medium according to claim 1 of the present invention, and FIG. 5 is a cross-sectional view taken along line AA of FIG.

As shown in FIG. 1, the thermosensitive magnetic recording medium 1 is provided with a concealing layer 3 on the periphery of a metal thin film layer 2, and the surface of the thermosensitive magnetic recording medium 1 is concealed by the concealing layer 3 and the thermosensitive printing surface. It is divided into seven.

Further, as shown in FIG. 2, the printing area can be divided according to the type of information to be printed by making the thermal printing section empty. Further, as shown in FIG. 3, the concealing layer may be provided as a part of the design of the thermosensitive magnetic recording medium. Further, by printing a barcode in the same manner as the concealing layer as shown in FIG. 4, forgery of the magnetic recording medium can be prevented.

FIG. 5 is a sectional view taken along line AA of FIG. A magnetic recording layer 5, a metal thin film layer 2,
The concealing layer 3 is laminated in order, and the protective layer 6 is further laminated thereon.

Each layer constituting the thermosensitive magnetic recording medium 1 may be provided with a coloring layer or an adhesive layer in addition to the magnetic recording layer, the metal thin film layer, the concealing layer, and the protective layer.

Next, the base and each layer constituting the thermosensitive magnetic recording medium 1 will be described in detail. The substrate 4 has a sheet shape or a plate shape, and the material of the substrate 4 includes nylon, cellulose diacetate, cellulose triacetate, polystyrene, polyethylene, polypropylene,
Plastics such as polyester, polyimide, and polycarbonate, metals such as copper and aluminum, paper, impregnated paper, and the like can be used alone or in combination as a composite. A preferable material may be appropriately selected from the above materials in consideration of physical properties required for the substrate, for example, strength, rigidity, concealing property, light opacity and the like. The thickness of the substrate 4 is about 0.005 to 5 mm.

The magnetic recording layer 5 is made of γ-Fe ₂ O ₃ ,
Co-coated γ-Fe ₂ O ₃ , Fe ₃ O ₄ , CrO ₂ , F
e, Fe-Cr, Fe-Co, Co-Cr, Co-N
i, MnAl, Ba ferrite, Sr ferrite and other known magnetic fine particles are dispersed in an appropriate resin or ink vehicle by a conventionally known coating method such as a gravure method, a roll method, or a knife edge method. It can be formed on the base 4. The magnetic recording layer 5
Can be formed on the base 4 by using a metal or alloy such as Fe, Fe—Cr, Fe—Co, or Co—Cr or an oxide thereof by a vacuum deposition method, a sputtering method, a plating method, or the like.

When the magnetic recording layer 5 is formed by a coating method, its thickness is 1 to 100 μm, preferably 5 to 100 μm.
About 20 microns. When the magnetic recording layer 5 is formed by a vacuum evaporation method, a sputtering method, or a plating method, the thickness of the magnetic recording layer 5 is 100 to 10000Å, preferably 500
It is about 2000 mm.

As a resin or an ink vehicle in which magnetic fine particles such as γ-Fe ₂ O ₃ are dispersed, butyral resin, vinyl chloride / vinyl acetate copolymer resin, urethane resin, polyester resin, cellulose resin, acrylic resin, A styrene / maleic acid copolymer resin or the like is used, and if necessary, a rubber-based resin such as a nitrile rubber or a urethane elastomer is added. Further, a surfactant, a silane coupling agent, a plasticizer, a wax, a silicone oil, carbon, and other pigments may be added to the dispersion in which the magnetic fine particles are dispersed in the resin, if necessary. .

The metal thin film layer 2 is made of Fe, Co, Ni, S
n, Al, Mg, Ti, Cr, Bi, In, Pb, T
e, Cd, Zn, Fe-Co, Fe-Cr, Fe-V,
Fe-Ni, Fe-Pt, Fe-Pd, Fe-Cu, F
e-Zn, Co-Ni, Co-Cr, Co-V, Co-
Cu, Co-Mn, Co-P, Ni-Cr, Ni-C
u, Ni-Zn, Ni-V, Ni-Mn, Fe-Co-
Ni, Fe-Mn-Co, Fe-Ni-Cr, Fe-N
i-Mn, Fe-Co-Cr, Co-Mn-Ni, Co
—Ni—P, γ-Fe ₂ O ₃ , Fe ₃ O ₄ , Co-doped iron oxide, Co-coated iron oxide, CrO ₂ , BaO · 6Fe _{2
O 3, SrO · 6Fe 2 O} 3 mixture vacuum deposition of a metal or alloy, or of these, such as a sputtering method, or plating method, can be formed on a magnetic recording layer provided on the substrate 4. Since the metal thin film layer 2 plays a role as a heat-sensitive recording layer, it preferably has a low melting point. The thickness of the metal thin film layer is 100 to 10000Å.
Preferably, it is about 500 to 1000 °.

The masking layer 3 is made of a cellulose derivative such as ethyl cellulose, ethyl hydroxyethyl cellulose, cellulose acetate propionate or cellulose acetate;
Styrene resin such as polystyrene and poly-α-methylstyrene or styrene copolymer resin, homo- or copolymer resin of acrylic resin such as polymethyl methacrylate, polyethyl methacrylate, polyethyl acrylate, polybutyl acrylate or methacrylic resin Rosin, rosin modified maleic resin, rosin modified phenol resin, rosin ester resin such as polymerized rosin, polyvinyl acetate resin, coumarone resin, vinyl toluene resin, vinyl chloride resin, polyester resin, polyurethane resin, butyral resin, epoxy resin, etc. Various pigments are added to the binder according to the color of the hiding layer. For example, when matching the color of the concealing layer with the metallic luster of the underlying metal thin film layer, it is desirable to use a silver pigment. In addition, this silver pigment has a composition of aluminum, the shape of the aluminum particles is in the form of scale, and the particle size is 7 to 8 μm at the maximum, and the aluminum particles are uniformly arranged in the coating film, It is desirable to use a non-leafing type that is rich in rust prevention and adhesion. If necessary,
After adding a plasticizer, a stabilizer, a wax, a grease, a drying agent, a drying aid, a curing agent, a thickening agent, and a dispersing agent, using a colored paint or ink that is sufficiently kneaded with a solvent or a diluent, A desired portion can be formed by a coating method such as a usual gravure method, a roll method, a knife edge method, an offset method, a silk screen method, or a printing method.

The protective layer 6 can be formed by laminating a synthetic resin film, by an extrusion coating method, or by applying a synthetic resin paint. As the synthetic resin for forming the protective layer, those similar to the synthetic resins used for forming the concealing layer can be widely used in consideration of the use or the adhesion to other layers. In particular, the use of a thermosetting synthetic resin is advantageous in terms of surface hardness and prevention of contamination, and the use of a paint containing an ultraviolet curable synthetic resin allows instantaneous curing after application. preferable. Also, the surface can be made releasable by adding silicone or the like to the protective layer.

Hereinafter, the present invention will be described with reference to Examples.
The present invention is not limited to these examples. Unless otherwise specified, all parts are parts by weight.

EXAMPLE A magnetic paint having the following composition was applied on polyethylene terephthalate having a thickness of 188 μm by a gravure coating method to form a magnetic recording layer having a thickness of 10 μm. Then, Sn was measured thereon by a vacuum evaporation method using a quartz crystal oscillator to measure the thickness of the film to a thickness of 500 ° to form a metal thin film layer as a heat-sensitive recording layer. Used, 4-5μm thick by silk screen printing,
A hiding layer was formed at a drying temperature of 80 ° C. Composition of magnetic paint: 75 parts of Co-coated γ-Fe ₂ O ₃ (“X-6000” manufactured by Titanium Industry Co., Ltd.) 10 parts of partially saponified vinyl chloride / vinyl acetate copolymer resin (“VINYLITE VAGH” manufactured by Union Carburite) ) Polyurethane elastomer resin 10 parts ("Sanbren IB114B" manufactured by Sanyo Chemical Industries, Ltd.) Linear saturated polyester resin 5 parts ("Pylon RV53SS" manufactured by Toyobo Co., Ltd.) Isopropyl alcohol 50 parts Methyl ethyl ketone 50 parts Toluene 50 parts Isocyanate-based curing agent 3 parts ( "AT Mitech NY-220A" manufactured by Mitsubishi Kasei Co., Ltd. Composition of coloring paint: 50 parts of partially saponified vinyl chloride / vinyl acetate copolymer resin ("Vinylite VAGH" manufactured by Union Carbarite Co.) 10 parts of silver pigment (aluminum particles, Particle size 7 ~ 8μm) Methyl ethyl ketone 5 parts Toluene 5 copies

[0021]

As described above, the thermosensitive magnetic recording medium of the present invention is provided with a concealing layer mainly composed of a pigment and a binder on the periphery thereof, so that the metal thin film layer of the thermosensitive magnetic recording medium is discharged by static electricity. Even if it is destroyed mainly at the peripheral edge of the thermosensitive magnetic recording medium due to a phenomenon or the like, there is an effect that the color of the lower magnetic recording layer can be prevented from being exposed.

Further, by providing the concealing layer as a part of the design in addition to the peripheral portion on the metal thin film layer of the thermosensitive magnetic recording medium, in addition to preventing the color of the lower magnetic recording layer from being exposed, the appearance of the concealing layer can be reduced. An excellently beautiful thermosensitive magnetic recording medium can be provided.

[Brief description of the drawings]

FIG. 1 is a front view of a thermosensitive magnetic recording medium according to the present invention.

FIG. 2 is a front view of a thermo-sensitive magnetic recording medium in which a thermo-sensitive printing section has an open window;

FIG. 3 is a front view of a thermosensitive magnetic recording medium provided with a concealing layer as a part of a design.

FIG. 4 is a front view of a thermosensitive magnetic recording medium in which a concealing layer is provided in the same manner as a bar code for preventing forgery.

FIG. 5 is a sectional view of a thermosensitive magnetic recording medium according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Thermal magnetic recording medium 2 Metal thin film layer 3 Concealment layer 4 Substrate 5 Magnetic recording layer 6 Protective layer 7 Thermal printing surface 8 Bar code for prevention of forgery

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B42D 5/00 B42D 15/10 551 B41M 5/40 G06K 19/06 G11B 5/80

Claims (1)

(57) [Claims] 1. A magnetic recording layer on which a visible information is recorded on a substrate.
In a thermosensitive magnetic recording medium in which a metal thin film layer and a protective layer are sequentially laminated, a face is formed on a peripheral portion on the metal thin film layer.
A thermosensitive magnetic recording medium comprising a concealing layer mainly composed of a material and a binder .