JP3021585B2 - Thermosensitive magnetic recording medium and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial application field> The present invention relates to a thermosensitive magnetic recording medium, and particularly, can surely hide a magnetic recording layer and perform visible recording on the magnetic recording layer, Further, the present invention relates to a thermosensitive magnetic recording medium capable of performing high-contrast visual recording by using a low-melting-point nonmagnetic metal material, and a method of manufacturing the same.

<Prior Art> Magnetic recording media are easy to write, read, and rewrite information, can be machine-processed, and can be manufactured at low cost, so that credit cards, cash cards,
It is widely used for prepaid cards such as ID cards, commuter passes, and telephone cards.

In recent years, in addition to recording fixed information, identification information, and variable information on a magnetic recording layer, in order to provide the convenience of the card holder, information that can be viewed when used (hereinafter referred to as visible information)
Has been recorded on the surface of a card, and in particular, in a prepaid card, the same value information as that of a magnetic recording can be visually recognized without using a reader.

Conventionally, as a recording means that can be visually observed on a magnetic recording medium having a magnetic recording layer, a thermosensitive coloring layer is provided on a substrate opposite to the magnetic recording layer or provided in a portion not overlapping with the magnetic recording layer. . Therefore, when the surface of the magnetic recording layer occupies a large area, there is a drawback that pre-printing of characters and pictures as visible information or a space for recording visible information by a thermal head or the like is restricted.
No. 4333, a heat-sensitive magnetic recording medium having a heat-sensitive recording layer formed directly on a magnetic recording layer as described in JP-A-59-199285, JP-A-59-199284, and JP-A-60-18388. As described, a magnetic recording medium in which a metal thin film layer is formed on a magnetic recording layer has been devised.

<Problems to be Solved by the Invention> However, in the heat-sensitive recording medium in which the heat-sensitive recording layer is formed directly on the magnetic recording layer, the hue of the magnetic material itself of the magnetic recording layer becomes the base color on one side of the medium. However, since the contrast is not good, the recorded information is difficult to see and lacks convenience.

A magnetic recording medium with a metal thin film layer formed on a magnetic recording layer prints and records by partial melting by heating printing of a thermal head. However, since printing sensitivity is low, high energy is required for heating printing to improve printing quality. This has the disadvantage that the load on the thermal head increases.

Therefore, the present invention has been made to solve the above problems, and enables magnetic information and visible information to be recorded on the same surface of a substrate, and also allows visible information to be recorded with higher contrast and more clearly. It is an object of the present invention to provide a thermosensitive magnetic recording medium and a method for manufacturing the same.

<Means for Solving the Problems> The present invention has been made to achieve the above object. (1) At least a magnetic recording layer, a metal thin film layer not using a resin binder, and a thermosensitive coloring layer are sequentially laminated on at least a substrate. A thermosensitive magnetic recording medium characterized by being formed.

(2) More preferably, in the thermosensitive magnetic recording medium, the metal thin film layer is a low-melting nonmagnetic metal material such as Sn, Bi, In, Cd, Pb, Zn, Te, or Al, or an alloy thereof, or Characterized in that it is a metal deposited film using any of the low melting point nonmagnetic metal compounds described above.

(3) In the method for manufacturing a thermosensitive magnetic recording medium in which a magnetic recording layer, a metal thin film layer, and a thermosensitive coloring layer are sequentially laminated on at least a substrate, a release layer and a resin binder are not used on a base film. A method for manufacturing a thermosensitive magnetic recording medium, comprising: transferring a transfer sheet, in which a metal thin film layer and an adhesive layer are sequentially laminated, onto a magnetic recording layer formed on a substrate.

(4) In the method for manufacturing a thermosensitive magnetic recording medium, in which a magnetic recording layer, a metal thin film layer and a thermosensitive coloring layer are sequentially laminated on at least a substrate, the metal is directly deposited on the magnetic recording layer formed on the substrate by vapor deposition. A method for manufacturing a thermosensitive magnetic recording medium, comprising forming a thin film layer.

(5) More preferably, the method for producing a thermosensitive magnetic recording medium is characterized in that the metal thin film layer is a low-melting nonmagnetic metal material such as Sn, Bi, In, Cd, Pb, Zn, Te, or Al, or an alloy thereof; Alternatively, any one of these low-melting nonmagnetic metal compounds is used.

<Function> In the present invention, the magnetic recording layer is reliably concealed by the metal thin film layer, and the color-forming portion of the heat-sensitive color-forming layer formed on the same surface of the recording medium has high color and high contrast with respect to the surrounding colors. Furthermore, by making the metal thin film layer a low-melting non-magnetic metal material, the metal thin film layer is also partially melted by the thermal printing on the thermosensitive coloring layer, and the magnetic recording layer is directly exposed to the coloring portion of the thermosensitive coloring layer, and the base color is changed. Therefore, the coloring portion of the heat-sensitive coloring layer provides a higher contrast with surrounding colors as well as coloring, so that magnetic information and visible information that can be easily visually confirmed can be formed on the same surface of the recording medium. . In addition, the metal thin film layer can be easily formed.

<Example> Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a partially enlarged cross-sectional view showing a sharp configuration of a thermosensitive magnetic recording medium (1) according to an embodiment of the present invention. A magnetic recording layer (3) and a metal thin film layer (4) are formed on a substrate (2). , A resin layer (5), a thermosensitive coloring layer (6), and a protective layer (7).
The magnetic recording layer (3) may be a part on the substrate (2) or the whole surface. Further, the metal thin film layer (4) may be only a portion corresponding to the thermosensitive coloring layer (6) formed on a part of the base (2), or may be the entire surface.

The base (2) can be used alone or in combination of plastics such as polyvinyl chloride, polyester, polycarbonate, polymethyl methacrylate, and polystyrene, paper, synthetic paper, and the like. The substrate (2) has physical properties required according to the use of the recording medium, for example, strength,
It is possible to select from the above materials in consideration of rigidity, concealing property, light opacity and the like.

The magnetic recording layer (3) is composed of γ-Fe ₂ O ₃ , Co-coated γ-Fe ₂ O ₃ ,
₃ O ₄ , CrO ₂ , Fe, Fe-Cr, Fe-Co, Co-Cr, Co-Ni, MnA
l, a magnetic fine particle dispersion containing magnetic fine particles such as Ba ferrite or Sr ferrite as a main component is coated on a substrate (2) by a solvent coating method such as bar coating, blade coating, air knife coating, gravure coating, roll coating, or screen printing. It is formed through a coating and drying process by a known coating method such as a coating method. Generally, the coercive force of the magnetic recording layer (3) is 1500 to 3000 (Oe), and the residual magnetic flux is 1.0 to 2.0 (Maxw).
ell / cm).

The metal thin film layer (4) is a white non-magnetic metal thin film layer. Examples of such a metal include low melting point metals such as Sn, Bi, In, Cd, Pb, Zn, Te, and Al. It is preferable to use a metal, an alloy thereof, or a metal compound thereof in consideration of toxicity and the like, and is formed by a vacuum evaporation method, a sputtering method, an ion plating method, a plating method, or the like.

The resin layer (5) is made of an acrylic resin, a styrene resin,
Metal thin film layer (4) mainly composed of polyester resin etc.
The adhesion between the thermosensitive recording layer (6) and the thermosensitive recording layer (6) can be improved, and if necessary, it can be provided through a coating and drying process by the above-mentioned coating method.

The heat-sensitive coloring layer (6) is composed mainly of a polymer binder and a heat-sensitive coloring material, and is prepared by dissolving the polymer binding agent in a coating liquid in which the heat-sensitive coloring material is dispersed with water or a suitable solvent. The dispersion liquid is formed through a coating and drying process by the coating method described above. As the polymer binder, hydroxyethyl cellulose, carboxymethyl cellulose, polyvinyl alcohol, starch, styrene-maleic acid copolymer, polymethyl methacrylate, homo- or copolymer of methacrylic resin such as polyethyl methacrylate, polystyrene, acrylic -Styrene copolymers, polyester resins, chroman resins, ABS resins, nitrocellulose and the like can be used. The heat-sensitive coloring agents are roughly classified into two types: a metal compound coloring type and a dye coloring type. Specifically, the metal compound coloring type is stearic acid secondary
Combination of iron, ferric myristate and tannic acid, gallic acid, Ag, Pb, Hg of oxalic acid, combination of Th salt and thiouric acid, sodium thiosulfate, Ni, Co, Cu salt of stearic acid and Ca
Combination with S, SrS, BaS, silver oxalate, mercury oxalate with glycerin, polyhydroxy alcohol, silver behenate, silver stearate with hydroquinone, spiroindane, ferric laurate, pelargonic acid Combinations of iron and thiocesylcarbazites, lead caproate, combinations of lead behenate and thiourea derivatives, ferric stearate, combinations of copper stearate and lead dibutylthiocarbamate, nickel acetate and thiooxalic acid , Thioacetamide, a combination of a molybdate of an organic amine and an aromatic polyhydric hydroxy compound, and the like. On the other hand, the dyeing and coloring type is a combination of a developer having a phenolic hydroxyl group and a colorless leuco dye.
4'-isopropylidenephenol, benzyl-p-hydroxybenzoate, 4,4'-dihydroxy-3,5'-
Diallyl diphenyl sulfone, methyl-bis (hydroxyphenyl) acetate, gallic acid ester, p-phenylphenol and the like. Leuco dyes include crystal violet lactone, 3-indolino-3
-P-dimethylaminophenyl-6-dimethylaminophthalide, 3-diethylamino-7-chlorofluoran,
2- (2-chlorophenylamine) -diethylaminofluoran, 2- (2-fluorophenylamino) -6
Diethylaminofluoran, 2- (2-fluorophenylamino) -di-n-butylaminofluoran, 3-diethylamino-7-cyclohexylaminofluoran,
3-diethylamino-5-methyl-7-t-butylfluoran, 3-diethylamino-6-methyl-7-anilinofluoran, 3-diethylamino-6-methyl-7-
p-Butylanilinofluoran, 3-cyclohexylamino-6-chlorofluoran, 2-anilino-3-methyl-6- (N-ethyl-p-toluidino) -fluoran, 3-pyrrolidino-6-methyl-7 -Anilinofluoran, 3-pyrrolidino-7-cyclohexylaminofluoran, 3-N-methylcyclohexylamino-6-methyl-7-anilinofluoran, 3-N-ethylpentylamino-6-methyl-7- Anilinofluoran and the like can be mentioned. The thermosensitive coloring material used in the thermosensitive magnetic recording medium of the present invention can be used as long as it satisfies the above-mentioned conditions, in addition to the above-mentioned materials or combinations.

The protective layer (7) is made of a thermosetting resin, an ultraviolet curing resin, or the like.
For example, a polyester resin, methacrylic resin, other urethane resin, vinyl chloride acetate resin, nitrified cotton is dissolved in a suitable solvent, and the coating liquid is applied by any of the above-described coating methods,
It is formed by drying. In addition, the polymer binder used for the heat-sensitive coloring layer (5) can be similarly used as a coating liquid for forming the protective layer (7). Further, a lubricant can be added to the coating liquid for the purpose of improving the suitability for the thermal head. In order to satisfy the magnetic output characteristics of the magnetic recording layer, the thickness of the layer above the magnetic recording layer (3) (in this case, a metal thin film layer, a heat-sensitive recording layer, etc.) is preferably 8 μm or less as a whole.

Thermosensitive magnetic recording medium (1) of the present invention having the above configuration
The magnetic head can perform magnetic recording and reproduction, and the thermal head can record characters such as date and balance, pictures, and visible information of images. Due to the presence of the thin film layer, the concealment of the magnetic recording layer causes the colored portion to have a high contrast with respect to the surrounding colors.If the metal thin film layer is a low-melting nonmagnetic metal material, the heated print portion of the thermal head melts, Since the color of the magnetic recording layer is in direct contact with the thermosensitive coloring layer, it becomes a colored portion having a higher contrast with respect to the surrounding color of the thermosensitive coloring layer, and visible information that can be easily identified is obtained.
In addition, the thermosensitive magnetic recording medium of the present invention can be formed arbitrarily in accordance with the application. For example, if the medium is molded into a card shape, it can be used as a thermosensitive magnetic recording card.

Next, a method for manufacturing a thermosensitive magnetic recording medium according to the present invention will be described.

FIG. 2 is a cross-sectional view showing a configuration example of the transfer sheet (10) according to the first method of manufacturing a thermosensitive magnetic recording medium of the present invention. A release film (12), a metal thin film layer (13), a resin layer (14), and an adhesive layer (15) are sequentially laminated on a support film (11) as a base film.

As the support film (11), for example, polyester, acetate, polycarbonate or the like is used. The release layer (12) is mainly composed of, for example, an acrylic resin or an acrylic / vinyl resin, and has a thickness of 0.5 to 2 μm.

The metal thin film layer (13) is a white nonmagnetic metal thin film layer formed by a vacuum deposition method, a sputtering method, an ion plating method, a plating method, or the like, and has a thickness of 0.03.
0.00.08 μm.

This kind of metal is especially called low melting point metal
It is preferable to use metals such as Sn, Bi, In, Cd, Pb, Zn, Te, and Al, alloys thereof, and metal compounds thereof in consideration of toxicity and the like.

The resin layer (14) is made of acrylic resin, styrene resin,
Polyester resin etc. as the main component, the thickness of 0.5 ~
2 μm.

The adhesive layer (15) has an acrylic resin, a vinyl resin or the like as a main component, and has a thickness of 0.5 to 2 μm. In addition,
If the adhesive layer itself has good adhesion to the metal thin film layer, there is no need to provide a resin layer.

In consideration of magnetic characteristics, it is needless to say that each layer on the magnetic recording layer (16) is preferably as thin as possible.

In the first method for manufacturing a thermosensitive magnetic recording medium of the present invention (the process is not shown), the transfer sheet (10) shown in FIG. A magnetic particle formed by applying and drying the magnetic fine particle dispersion on a substrate (17) by a known coating method such as a bar coat, a blade coat, an air knife coat, a gravure coat, a roll coat or the like, or a screen print method. The recording layer (16) is superposed on the recording layer (16) via the adhesive layer (15), and is transferred by heating and pressing. After the transfer, the support is peeled off, and a known solvent coating method such as a bar coating, a blade coating, an air knife coating, a gravure coating, a roll coating or the like, or a screen printing method of the above-mentioned heat-sensitive recording material is formed on the release layer (12). The heat-sensitive coloring layer (18) is formed by coating and drying according to the coating method described above, and a protective layer (19) can be further provided as necessary. FIG. 3 shows a partially enlarged cross-sectional view of the thermosensitive magnetic recording medium thus formed.

In the second method for producing a thermosensitive magnetic recording medium of the present invention (the process is not shown), first, a magnetic fine particle dispersion comprising the above-mentioned magnetic substance is coated on a substrate (2) by bar coating.
Blade coat, air knife coat, gravure coat,
The above metal or its alloy or metal compound is deposited on the magnetic recording layer (3) formed by coating and drying by a known coating method such as a solvent coating method such as a roll coating method or a screen printing method, by a vacuum evaporation method or a sputtering method. A metal thin film layer (4) is formed by a method, an ion plating method, a plating method, or the like, and the resin layer (5) is mainly composed of an acrylic resin, a styrene resin, a polyester resin, or the like. ) And the thermosensitive coloring layer (6) can be improved in adhesion, and can be provided as necessary. A heat-sensitive coloring layer (6) is formed by coating and drying the above-mentioned heat-sensitive recording material by a known coating method such as a bar coat, blade coat, air knife coat, gravure coat, roll coat or the like, or a screen print method. Form. If necessary, a protective layer (7)
Can be provided. Thus, a thermosensitive magnetic recording medium as shown in FIG. 1 is obtained.

Next, a specific example will be described with reference to the following example. In the examples, "parts" indicates "parts by weight".

Example 1 (a) Composition of magnetic coating material for magnetic recording layer BaO-6Fe ₂ O ₃ 40 parts Vinyl acetate vinyl chloride resin 10 parts (Slec A manufactured by Sekisui Chemical Co., Ltd.) 5 parts saturated polyester resin (manufactured by Toyobo Co., Ltd.) Byron 103) Polyurethane elastomer 7 parts (N-2304, Nippon Polyurethane Co., Ltd.) Oleic acid 5 parts Toluene 30 parts Methyl isobutyl ketone 30 parts Isocyanate curing agent 3 parts (Nippon Polyurethane Co., Ltd. Coronate HL) Triethylene diamine 0.5 parts (B) Composition of thermosensitive coloring layer coating composition 5 parts of ferric myristylate 1.5 parts of tannic acid 10 parts of methacrylic resin (BR-60 manufactured by Mitsubishi Rayon Co., Ltd.) 70 parts of toluene (c) Composition of protective layer stearic acid Zinc 1 part Methacrylic resin 8 parts (Rohm & Harras Co., Ltd. Paraloid A-11) Toluene 9 parts On the 188 μm thick white PET sheet from the above composition (a) That a magnetic paint for the magnetic recording layer was applied by gravure coating method to form a magnetic recording layer having a thickness of 15 [mu] m.

On the other hand, an acrylic resin was applied on a 25 μm-thick polyester film by a gravure coating method, and 0.7 to 1 μm was applied.
m to form a release layer, and then aluminum
A metal thin film layer is formed by vacuum evaporation to a thickness of μm. Next, apply by gravure coating method, and 0.7 ~ 1μm
To form a resin layer, and an acrylic resin was applied by a gravure coating method to form a transfer sheet as an adhesive layer having a thickness of 0.7 to 1 μm.

The transfer sheet is transferred onto the magnetic recording layer of the abandoned body via an adhesive layer by applying heat and pressure, the polyester film is peeled off, and the thermosensitive coloring layer paint having the composition (b) is applied by a gravure coating method. Thus, a thermosensitive coloring layer having a thickness of 5 μm was formed.

Next, a protective layer paint having the composition (c) is applied by a gravure coating method to form a dry film having a thickness of 2 μm.

Example 2 A magnetic paint for a magnetic recording layer having the composition of (a) of Example 1 was applied on a 188 μm thick white PET sheet by a gravure coating method to form a 15 μm thick magnetic recording layer.

Next, aluminum is deposited on the magnetic recording layer by vacuum evaporation.
The metal thin film layer (13) is formed by vapor deposition to a thickness of 0.04 μm.

Next, a gravure coat method is applied to the salt vinyl acetate resin.
A resin layer is formed to a thickness of 0.7 to 1 μm.

Next, a coating for a thermosensitive coloring layer having the composition of (b) in Example 1 is applied by a gravure coating method to form a thermosensitive coloring layer to a thickness of 5 μm.

Further, the protective layer paint having the composition of (c) in Example 1 is applied by a gravure coating method to form a protective layer having a thickness of 2 μm, thereby obtaining the thermosensitive magnetic recording medium of the present invention.

In the thermosensitive magnetic recording media obtained in the above Examples 1 and 2, the magnetic recording layer is completely concealed by the metal thin film layer, and the surface has considerable luster. If the metal thin-film layer is a low-melting non-magnetic metal material, the metal thin-film layer in the heated print portion of the thermal head melts together with the color formation of the heat-sensitive coloring layer, Since the color of the recording layer is directly exposed to the heat-sensitive coloring layer, the color of the exposed magnetic recording layer is used as the base color, and the coloring portion of the heat-sensitive coloring layer has a higher contrast with respect to the surrounding colors. can get.

<Effects of the Invention> As described above, the thermosensitive magnetic recording medium according to the present invention includes the magnetic recording layer and the thermosensitive coloring layer, so that the magnetic information and the visible information are simultaneously recorded, so that a limited number of recording media can be used. The recording space of the recording medium can be effectively used, the magnetic recording layer can be reliably concealed by the metal thin film layer, and a high contrast can be obtained with the coloring portion of the thermosensitive coloring layer formed on the same surface of the recording medium. Is a low-melting non-magnetic metal material, the heating printing of the thermal head causes the heating printing portion of the thermosensitive coloring layer to develop color and the heating printing portion of the metal thin-film layer melts, and the magnetic recording layer directly forms the coloring portion of the thermosensitive coloring layer. , The colored portion of the thermosensitive coloring layer has a higher contrast with respect to the surrounding colors, and it is easy to confirm visible information.

In addition, the metal thin film layer can be formed in close contact with the magnetic recording layer, and the manufacturing process can be simplified.

[Brief description of the drawings]

FIG. 1 is a partially enlarged sectional view showing a configuration of a thermosensitive magnetic recording medium according to the present invention, FIG. 2 is a partially enlarged sectional view showing a configuration example of a transfer sheet, and FIG. 3 is a thermosensitive magnetic recording of the present invention. FIG. 3 is a partially enlarged cross-sectional view of a thermosensitive magnetic recording medium according to a first method for manufacturing a medium. (1), (20) ... thermosensitive magnetic recording medium (2), (17) ... base (3), (16) ... magnetic recording layer (15) ... adhesive layer (4), (14) ... ... Resin layer (5), (13) ... Metal thin film layer (12) ... Release layer (6), (18) ... Thermal coloring layer (7), (19) ... Protective layer (10) ... … Transfer sheet (11) …… Support film

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B42D 15/10 501 B42D 15/10 551 B41M 5/26

Claims (5)

(57) [Claims] 1. A thermosensitive magnetic recording medium comprising a magnetic recording layer, a metal thin film layer in which no resin binder is used, and a thermosensitive coloring layer sequentially laminated on at least a substrate. 2. The method according to claim 1, wherein said metal thin film layer is composed of Sn, Bi, In, Cd, Pb, Z
2. A metal vapor-deposited film using a low-melting nonmagnetic metal material such as n, Te, or Al, an alloy thereof, or any of these low-melting nonmagnetic metal compounds. Thermosensitive magnetic recording medium. 3. A method for producing a thermosensitive magnetic recording medium comprising at least a magnetic recording layer, a metal thin film layer and a thermosensitive coloring layer sequentially laminated on a substrate, wherein a release layer and a resin binder are not used on a base film. A method for manufacturing a thermosensitive magnetic recording medium, comprising: transferring a transfer sheet, in which a metal thin film layer and an adhesive layer are sequentially laminated, onto a magnetic recording layer formed on a substrate. 4. A method for manufacturing a thermosensitive magnetic recording medium comprising a magnetic recording layer, a metal thin film layer and a thermosensitive coloring layer sequentially laminated on at least a substrate, wherein a metal is directly deposited on the magnetic recording layer formed on the substrate by vapor deposition. A method for manufacturing a thermosensitive magnetic recording medium, comprising forming a thin film layer. 5. The method according to claim 1, wherein said metal thin film layer is composed of Sn, Bi, In, Cd, Pb, Z
A low-melting non-magnetic metal material such as n, Te, or Al, an alloy thereof, or a low-melting non-magnetic metal compound is used. A method for producing the thermosensitive magnetic recording medium according to the above.