JPH0558043A - Thermal recording medium - Google Patents

Abstract

PURPOSE:To make thermally recorded visible data clear, to enhance the aesthetic feeling thereof and to facilitate the reading thereof by providing a magnetic recording layer, a metal membrane layer and a protective layer containing pearl pigment on a non-magnetic substrate. CONSTITUTION:A substrate 2 has a sheet or plate like shape and, as the material thereof, plastics such as polyvinyl chloride, nylon or cellulose diacetate, a metal such as copper or aluminum, paper and a composite of those materials are designated. A magnetic recording layer 3 can be formed on the substrate 2 by applying a dispersion wherein fine magnetic particles composed of gamma-Fe2O3 or Co coated gamma-Fe2O3 are dispersed in a proper resin or ink vehicle to the substrate and applying magnetic field orienting treatment to the coated substrate before or during drying.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal recording medium,
More specifically, the present invention relates to a heat-sensitive recording medium in which a metal thin film layer as a heat-sensitive recording layer and a protective layer which develops a color in a printed portion by heat-sensitive destruction are laminated.

[0002]

2. Description of the Related Art A magnetic recording medium in which a magnetic recording layer is provided on the surface of a substrate such as a plastic inevitably has invisible recorded information. Therefore, there is a demand for recording the information as visible information on the recording medium. ing.

As a method of recording visible information, characters, patterns, etc. are formed on a magnetic recording layer of a magnetic recording medium by a thermal destructive printing method using a thermal head.
For example, a heat-sensitive recording medium has been conventionally known in which individual information such as a bar code, an OCR character, a name, an expiration date, and a balance is recorded as visible information.

The visual quality of the visible information recorded on the heat-sensitive recording layer is determined by the difference in light reflectance between the printed portion (metal thin film layer destroyed portion) and the non-printed portion (metal thin film layer non-destructed portion), contrast, and the like. Therefore, when it is intended to improve the readability, clarification, or aesthetic value of printed information, it is inevitably regulated by the type of metal thin film layer material and the material of the magnetic recording layer below the metal thin film layer. However, the hue is conventionally black or brown of the magnetic recording layer. As a method for obtaining a desired and satisfactory hue, for example, Japanese Patent Laid-Open Publication No.
No. 9-199284, JP-A-60-18388, JP-A-60-52390 and the like disclose between the magnetic recording layer and the metal thin film layer or between the metal thin film layer and the upper protective layer. A method of providing a colored layer is known.

[0005]

However, this method is not always easy, and the provision of the colored layer increases the distance between the magnetic recording layer and the magnetic head, resulting in a decrease in magnetic output. There was a problem.

The present invention is intended to solve the problems associated with the prior art as described above, and has the following objects.

(A) Thermosensitively recorded visible images by freely adjusting the hue difference, lightness difference, saturation difference, etc. between the printed portion (metal thin film destruction portion) and the non-printed portion (metal thin film non-destruction layer). To provide a thermosensitive recording medium in which information is clarified, aesthetics are improved, and visible information is easily read. (B) To provide a recording medium with a small decrease in magnetic output by reducing the number of visible recording portions stacked on the magnetic recording layer. (C) Simplify the manufacturing process of the thermal recording medium by reducing the number of visible recording layers.

[0008]

According to the present invention, in the printing mechanism by the thermal destructive printing method, the low melting point metal thin film is destroyed and disappeared by the thermal head, and the lower magnetic recording layer is recognized as the printing portion. In consideration of the fact that even if a protective layer containing a pigment or a dye is provided on the metal thin film layer, the protective layer is not destroyed and disappeared in the thermal head, and only the metal thin film layer is destroyed and disappeared. As a result, the hue of the printed character portion by the conventional thermal destructive printing method was black or brown of the magnetic recording layer below the metal thin film layer, but the printed portion (the metal thin film layer destroyed portion was not provided with a new colored layer. ) Is colored, and the non-printed part (non-destructive part of the metal thin film layer) is colorless, and a protective layer containing a pearl pigment that transmits the color of the lower metal thin film is provided on the metal thin film layer to enable color printing. It was found that such a thermal recording medium can be obtained, and the present invention has been completed.

In order to solve the above problems, the present invention provides a heat-sensitive recording medium characterized by comprising a magnetic recording layer, a metal thin film layer and a protective layer containing a pearl pigment on a non-magnetic substrate. .

In the heat-sensitive recording medium of the present invention, a desired color print of red, purple, blue, green, blue, etc. can be formed by selecting various pearl pigments.

The present invention will be described in detail below with reference to the drawings.

The substrate 2 is in the form of a sheet or plate, and the material of this substrate is, for example, vinyl chloride,
Plastics such as nylon, cellulose diacetate, cellulose triacetate, polystyrene, polyethylene, polypropylene, polyester, polyimide, polycarbonate, or metals such as copper and aluminum,
Examples include paper, impregnated paper, and composites of these materials.Other than these, strength, rigidity, and
Any material can be used without particular limitation as long as it has a concealing property and a light transmitting property.

The magnetic recording layer 3 is composed of γ-Fe ₂ O ₃ , Co-deposited γ-Fe ₂ O ₃ , Fe ₃ O ₄ , CrO ₂ , Fe and Fe-C.
r, Fe-Co, Co-Cr, Co-Ni, MnAl,
After applying a dispersion of conventionally known magnetic fine particles such as Ba ferrite and Sr ferrite dispersed in an appropriate resin or ink vehicle by a known method such as a gravure method, a reverse method or a knife edge method, and before drying. Alternatively, it can be formed on the substrate 2 by performing a magnetic field orientation treatment during drying. It is preferable that the magnetic recording layer thus obtained is further subjected to a heating and pressing treatment as a post-process.

The magnetic recording layer 3 is made of Fe, Fe-C.
A metal such as r, Fe-Co, Co-Cr, or an alloy thereof may be used to form it on the substrate 2 by a vacuum deposition method, a sputtering method, a plating method, or the like.

When the magnetic recording layer is formed by a coating method, its thickness is preferably in the range of 1 to 100 μm.
The range of up to 30 μm is particularly preferred.

When the magnetic recording layer is formed by a vacuum vapor deposition method, a sputtering method, a plating method or the like, the thickness of the magnetic layer is preferably 100 angstroms to 1 μm, and particularly preferably 500 to 2000 angstroms.

The binder resin or ink vehicle in which magnetic fine particles such as γ-Fe ₂ O ₃ are dispersed is, for example, butyral resin, vinyl chloride-vinyl acetate copolymer resin, urethane resin, polyester resin, cellulose resin, acrylic resin. , Styrene-maleic acid copolymer resin and the like, and a rubber-based resin such as nitrile rubber or a urethane elastomer may be added to these resins, if necessary. If necessary, a surfactant, a silane coupling agent, a plasticizer, wax silicone oil, carbon and other pigments may be added to the magnetic coating material in which the magnetic fine particles are dispersed in the resin.

The amount of the vehicle used in the magnetic paint is preferably in the range of 10 to 30 parts by weight per 100 parts by weight of the magnetic powder.

The metal thin film layer 4 is made of Te, Sn, In, A.
a metal such as 1, Bi, Pb, Zn or an alloy thereof or a compound of the above metal such as Te-carbide,
The substrate 2 is formed by a vacuum deposition method, a sputtering method, a plating method, or the like.
It can be formed on the magnetic recording layer provided above.

Since the metal thin film layer 4 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 Å to 1 μm.
m is preferred, with a range of 500 to 1000 angstroms being particularly preferred.

The protective layer 5 is a coating film formed by dispersing a pearl pigment in a binder resin.

Examples of the binder resin include cellulose derivatives such as ethyl cellulose and cellulose acetate, styrene resins such as polystyrene, styrene copolymer resins, polymethyl methacrylate, polyethyl methacrylate, polyethyl acrylate, polyacrylic. Acrylic resin or methacrylic resin homo- or copolymer resin such as butylate, polyvinyl acetate resin, vinyltoluene resin, vinyl chloride resin, polyester resin, polyurethane resin,
Butyral resin etc. are mentioned.

Examples of the pearl pigment include iridin silver type, iridin iris color type and iridin coloring type pearl pigments manufactured by Merck Japan KK From the color of the colored print, iridin iris type “Iriodin 205”, “Iriodin 215”, “Iriodin 217”, “Iriodin 219”, “Iriodin 225”, “Iriodin 235” and the like are preferable.

The protective layer 5 is formed by adding a binder resin, a pearl pigment and, if necessary, a plasticizer, a stabilizer, a wax silicone oil, a curing agent, a curing catalyst, a dispersant, etc., and then using a solvent and a diluent. It can be provided on the metal thin film layer 4 by a well-known coating method or printing method such as a gravure method, a reverse method or a knife edge method using a sufficiently kneaded paint or ink.

When the protective layer is formed by the coating method, its thickness is preferably in the range of 0.5 to 10 μm.
The range of 3 μm is particularly preferable.

[0026]

EXAMPLES The present invention will be described below with reference to examples.
The invention is not limited to these examples.

In the examples and comparative examples, "parts" means "parts by weight" unless otherwise specified.

(Example 1) <Composition of magnetic paint> 100 parts of Ba-ferrite magnetic powder ("MC-127" manufactured by Toda Kogyo Co., Ltd.) 15 parts of vinyl chloride-vinyl acetate copolymer ("VAGH manufactured by Union Carbide Co., USA") ") Polyurethane resin 10 parts (" T-5206 "manufactured by Dainippon Ink and Chemicals, Inc.) Toluene 100 parts Methyl ethyl ketone 100 parts Cyclohexanone 100 parts

A magnetic recording layer having a thickness of 10 μm was formed by applying the above magnetic paint on a polyethylene terephthalate sheet having a thickness of 188 μm by a reverse method.

Then, tin was measured on the magnetic recording layer by a vacuum vapor deposition method by a film thickness measurement method using a quartz oscillator, and 50
A metal thin film layer serving as a heat-sensitive recording layer was formed by vapor deposition to a film thickness of 0 angstrom.

<Composition of protective coating (1)> 100 parts of acrylic resin (“KU-273” manufactured by Dainippon Ink and Chemicals, Inc.) 50 parts of pearl pigment (“Iriodin 215” manufactured by Merck Japan, Inc.) 10 parts of isocyanate curing agent ("D-750" manufactured by Dainippon Ink and Chemicals, Inc.) Toluene 250 parts Methyl ethyl ketone 250 parts

Further, the protective coating (1) of the above composition, which develops red color, was applied on the thermosensitive recording layer by a reverse method to form a protective layer having a thickness of 2 μm to obtain a thermosensitive recording medium.

(Example 2) A thermosensitive recording medium was prepared in the same manner as in Example 1 except that the protective paint (1) in Example 1 was replaced by a protective paint (2) which developed a purple color. Got

<Composition of protective coating (2)> Acrylic resin 100 parts (Dainippon Ink and Chemicals, Inc. “KU-273”) Pearl pigment 50 parts (Merck Japan “Iriodin 219”) Isocyanate curing agent 10 parts ("D-750" manufactured by Dainippon Ink and Chemicals, Inc.) Toluene 250 parts Methyl ethyl ketone 250 parts

(Example 3) A thermosensitive recording medium was prepared in the same manner as in Example 1 except that the protective coating (1) in Example 1 was replaced by a protective coating (3) having the following composition that developed a green color. Got

<Composition of protective coating (3)> 100 parts of acrylic resin (“KU-273” manufactured by Dainippon Ink and Chemicals, Inc.) 50 parts of pearl pigment (“Iriodin 235” manufactured by Merck Japan, Inc.) 10 parts of isocyanate-based curing agent ("D-750" manufactured by Dainippon Ink and Chemicals, Inc.) Toluene 250 parts Methyl ethyl ketone 250 parts

Comparative Example 1 A thermosensitive recording medium was obtained in the same manner as in Example 1 except that the protective coating material (1) was replaced with the protective coating material (4) having the following composition.

<Composition of protective coating (4)> Acrylic resin 100 parts (Dainippon Ink and Chemicals Incorporated “KU-273”) Talc pigment 50 parts (Matsumura Sangyo “# 5000 PJ”) Isocyanate curing agent 10 Part (Dainippon Ink and Chemicals, Inc. "D-750") Toluene 250 parts Methyl ethyl ketone 250 parts

Comparative Example 2 A magnetic recording layer having a thickness of 10 μm was formed by applying the above magnetic coating material on a polyethylene terephthalate sheet having a thickness of 188 μm by a reverse method.

Next, a colored coating material having the following composition was applied on the magnetic recording layer by a reverse method to form a colored layer of 3 μm.

<Composition of colored paint> Ink base 70 parts (Dainippon Ink and Chemicals Incorporated "NRB-115 red") Vinyl chloride-vinyl acetate copolymer 30 parts (US Union Carbide "VAGH") Isocyanate Hardener 3 parts (Dainippon Ink and Chemicals, Inc. "D-750") Toluene 30 parts Methyl ethyl ketone 30 parts

Then, on the colored layer, by a vacuum deposition method,
Tin was measured by a film thickness measurement method using a crystal oscillator, and was vapor-deposited to a film thickness of 500 Å to form a metal thin film layer which is a thermal recording layer.

Further, the protective coating material (4) used in Comparative Example 1 was applied on the thermosensitive recording layer by a reverse method to form a protective layer having a thickness of 2 μm to obtain a thermosensitive recording medium.

The thermosensitive recording media obtained in each of the examples and the comparative examples were punched out into a card shape, and numbers, Chinese characters, Roman characters, etc. were printed by a thermal head. The thermal head had an applied voltage of 24 V, a resistance value of 550 Ω, and an application time of 2.6 ms.

Next, the reproduction output voltage was measured with a magnetic card reader / writer. The magnetic card reader / writer used a magnetic head having a gap length of 30 μm, and the card transport speed was 190 mm / sec.

Table 1 shows the space loss, print color hue and resolution of the thermosensitive recording media obtained in each of the examples and the comparative examples. The resolution is a recording density of 500FCI / 200F.
It was expressed by the ratio of the reproduction output voltage of CI.

[0047]

[Table 1]

As is clear from Table 1, the heat-sensitive recording media obtained in the respective examples have a smaller space loss, can perform color printing, and can remarkably improve the resolution, as compared with the heat-sensitive recording media of the comparative examples. Understandable.

[0049]

The thermal recording medium according to the present invention has the following effects because it has a metal thin film layer and a protective layer containing a pearl pigment.

(A) By appropriately selecting the type of pearl pigment, it is possible to develop colors such as red, purple, green, blue, etc., and it is possible to facilitate the reading of visible information by the contrast of hue and improve the aesthetic appearance. it can. (B) Since one layer has two functions of a hue and a protective layer, it is possible to provide a magnetic recording medium with a small space loss and a high resolution, and to simplify the manufacturing process. Addition of the pigment (c) improves the durability as a protective layer.

[Brief description of drawings]

FIG. 1 is a sectional view of a thermal recording medium of the present invention.

[Explanation of symbols]

 1 Thermal recording medium 2 Base material 3 Magnetic recording layer 4 Metal thin film layer 5 Protective layer

Claims (2)

[Claims] 1. A heat-sensitive recording medium comprising a magnetic recording layer, a metal thin film layer, and a protective layer containing a pearl pigment on a non-magnetic substrate. 2. A print recording method for a magnetic recording medium, characterized in that the metal thin film layer of the thermal recording medium according to claim 1 is thermally destructed to develop a color.