JPH07172058A - Thermal magnetic recording material - Google Patents

Abstract

PURPOSE:To record many information amount from magnetic information and visible information by providing a magnetic recording layer on an entire surface of a base, providing a thermal color developing layer as a thermal recording layer via an anchor coating layer on an entire surface of the magnetic recording layer, and further providing a protective layer on the developing layer. CONSTITUTION:A thermal magnetic recording medium 1 is formed by forming a magnetic recording layer 3 and a thermal color developing layer 4, and a protective layer 5, an anchor coating layer 6 as required on a base 2 by a known coating method. The base 2 is formed of plastics, metal, paper, impregnated paper, etc., and a thickness of the layer 3 is preferably abut 5-20 micron. The layer 4 is formed of paint by using leuco dye, acidic developer, binder resin and organic solvent or water, and of about 5-15mum in thickness. The layer 5 is formed of synthetic resin. The layer 6 is formed of paint to enhance adhesive properties of the layers 3 and 4, and effectively prevents peeling of the thermal recording layer for the purpose of a forgery.

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 having a magnetic recording layer and a thermosensitive coloring layer.

[0002]

2. Description of the Related Art A magnetic recording medium having a magnetic recording layer provided on the surface of a substrate such as plastic is a credit card, cash card, ID card, boarding ticket, commuter pass, magnetic tape. Widely used as such. Such a magnetic recording medium has an advantage that the recording density is high and the recorded information cannot be easily read from the outside, but the recorded information is inevitably invisible, and therefore, these recording media In some cases, it may be necessary to record visible information in the. In such cases, it has been practiced to print characters, designs, etc. on the margins or the back surface of the base surface of the magnetic recording medium. However, there is a shortage of space for printing visible information, and there is a drawback that a sufficient amount of information cannot be printed.

Therefore, in recent years, a magnetic recording medium in which visible information such as characters and patterns is formed on the magnetic recording layer of the magnetic recording medium by a printing means has appeared. However, since the visible information is formed by various printing means, its contents are uniform and fixed, and there is a drawback that the change is scarce. Further, on the magnetic recording layer, for example, a bar code, an OCR character, a name,
Printing individual information such as the expiration date leads to an increase in manufacturing cost, which is not practical.

For this reason, it has been proposed to provide a thermosensitive coloring layer for coloring visible information by coloring by a heating means, but in the past, the thermosensitive coloring layer, which was often formed in a strip shape, was applied on the magnetic recording layer. Forming the color-forming layer requires a technique to make the surface uniform in the thermosensitive color-forming layer whose surface smoothness has a great influence on the printing sensitivity. Therefore, the manufacturing process becomes complicated and the cost is high. There was a problem that

As another form, it has been proposed to provide the magnetic recording layer and the thermosensitive recording layer on the same plane, or to provide the magnetic recording layer on the thermosensitive coloring layer, but both are manufactured at a practical stage. The process is complicated, and especially when the magnetic recording layer is provided on the thermosensitive coloring layer, it is necessary to pay attention to the temperature control during the magnetic layer formation so that the exothermic coloring layer does not develop color carelessly. However, there was a problem in that the solvent selection, etc. was restricted.

By the way, in recent years, forgery / alteration of magnetic recording media such as cash cards, credit cards, and commuter passes has become a big social problem, and many studies have been made on how to prevent forgery / alteration of magnetic recording information. However, a simple and effective method of forgery / alteration of magnetic recording information has not been found yet.

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

A) To provide a recording medium capable of incorporating a large amount of information including both magnetic information and visible information.

B) To provide a recording medium capable of easily recording individual visible information according to each situation.

C) To provide a recording medium which cannot easily forge or alter magnetic information.

D) To provide a recording medium which is capable of double-checking magnetic information and visible information and which is difficult to forge or alter.

[0012]

In a thermosensitive magnetic recording medium according to the present invention, a magnetic recording layer is provided on the entire surface of a substrate, and a thermosensitive recording layer is formed on the entire surface of the magnetic recording layer via an anchor coat layer. The present invention is characterized in that a coloring layer is provided, and a protective layer is further provided on the thermosensitive coloring layer, and the visible information is recorded by bringing a heating means such as a thermal head into contact with the thermosensitive coloring layer.

The present invention will be described below with reference to the preferred embodiments shown in the drawings.

As shown in FIG. 1, a thermosensitive magnetic medium 1 according to the present invention has a sheet-shaped or plate-shaped substrate 2, a magnetic recording layer 3 provided thereon, and a magnetic recording layer 3 formed on the substrate 2. The thermosensitive coloring layer 4 provided as a thermosensitive recording layer, and the protective layer 5 provided on the thermosensitive coloring layer 4 serve to protect the thermosensitive coloring layer 4. The magnetic recording layer 3 is provided entirely on the surface of the substrate 2. The thermosensitive coloring layer 4 is entirely provided on the surface of the magnetic recording layer 3. Further, an anchor coat layer (not shown) described later is formed between the magnetic recording layer 3 and the thermosensitive coloring layer 4.

Another specific example of the thermosensitive magnetic recording medium 1 according to the present invention is shown in FIGS. However, the protective layer is omitted in FIG. 2 and the anchor coat layer is omitted in FIG. 4.

In the thermosensitive magnetic recording medium 1 shown in FIG. 2, a magnetic recording layer 3, an anchor coat layer 6 and a thermosensitive coloring layer 4 are laminated in this order on a substrate 2, and the anchor coat layer is magnetic. It functions to strengthen the adhesion between the recording layer 3 and the thermosensitive coloring layer 4. Further, as shown in FIG. 5, a protective layer 5 can be provided on the thermosensitive coloring layer 4.

In the thermosensitive magnetic recording medium 1 shown in FIG. 4, a magnetic recording layer 3 and a thermosensitive coloring layer 4 are laminated in this order on both front and back surfaces of a substrate 2, and magnetic information and visible information are recorded. Many can be recorded.

In the thermosensitive magnetic recording medium 1 according to the present invention, a magnetic recording layer 3 and a thermosensitive coloring layer 4 and, if necessary, a protective layer 5 and an anchor coat layer 6 are provided on a substrate 2 by a gravure method and a roll method. It can be formed by a conventionally known coating method such as a knife edge method.

In some cases, a transfer laminate is prepared by temporarily laminating a thermosensitive coloring layer, a magnetic recording layer and a hot melt adhesive layer on a transfer substrate via a release layer, and using this laminate. The thermosensitive magnetic recording medium according to the present invention can also be manufactured by transferring the thermosensitive coloring layer and the magnetic recording layer onto the substrate.

Further, once prepared is a sticking laminate in which a magnetic recording layer and a thermosensitive coloring layer are laminated on a sticking substrate,
The thermosensitive magnetic recording medium according to the present invention can also be manufactured by providing an adhesive layer on the back surface of this laminate and integrally adhering the substrate and the sticking substrate via the adhesive layer. In this case, the adhesive substrate can function as a layer for smoothing the magnetic recording layer.

The substrate 2 is in the form of a sheet or a plate. As the substrate 2, plastics such as nylon, cellulose diacetate, cellulose triacetate, polystyrene, polyethylene, polypropylene, polyester, polyimide and polycarbonate, copper and aluminum are used. Metals such as, paper, and impregnated paper can be used alone or in combination to form a composite. Considering the physical properties required for the substrate, such as strength, rigidity, hiding power, and light opacity, a preferable material may be appropriately selected from the above materials. The thickness of the substrate 2 is 0.005
It is about 5 mm.

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, Fe.
-Cr, Fe-Co, Co-Cr, Co-Ni, MnA
1, a known magnetic fine particle such as Ba ferrite, Sr ferrite or the like dispersed in an appropriate resin or ink vehicle is used as a substrate by a conventionally known coating method such as a gravure method, a roll method or a knife edge method. 2 can be formed on. When the magnetic recording layer 3 is formed by such a coating method, the thickness is 1 to 100.
It is about micron, preferably about 5 to 20 micron. In this case, as the binder resin or the ink vehicle in which the 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 a rubber-based resin such as nitrile rubber or a urethane elastomer is added if necessary. Also,
In a dispersion in which magnetic particles are dispersed in the resin,
If necessary, surfactants, silane coupling agents, plasticizers, waxes, silicone oils, carbon and other pigments can be added.

Further, when the substrate is made of a relatively rough surface such as paper, there is an advantage that the metal thin film layer also functions as a coat layer for smoothing the surface of the substrate.

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.

In the present invention, in order to improve the recording resolution and the reading accuracy of visible information, it is particularly preferable to form the magnetic recording layer 3 by a thin film made of the above metal or its alloy. In the case of the layer structure of the present invention as described above, since the thermosensitive recording layer is formed on the magnetic recording layer, the recording resolution of the magnetic recording layer may decrease. Alternatively, this problem can be solved by using a thin film made of the alloy. Furthermore, the metal thin film as described above simultaneously becomes a reflective film,
The contrast of the visible information formed on the upper thermosensitive recording layer is further increased to make it easier to read, and the OCR
There is an advantage that the machine reading of a bar code or the like can be performed more accurately.

As described above, the vacuum deposition method, the sputtering method,
When the magnetic recording layer 3 is formed by a plating method, the film thickness is preferably 100 angstroms to 1 micron, preferably 500 to 2000 angstroms.

The thermosensitive coloring layer 4 is basically composed of a leuco dye, an acidic developer and a binder resin.

Examples of leuco dyes include triphenylmethane compounds such as crystal violet lactone and malachite green lactone; fluoran compounds such as 1,2-benzo-6-diethylaminofluorane; auramine compounds such as N-benzoylauramine; and phenothiazine. System: Spiropyran system and the like can be used.

As the acidic developer, a compound having a phenolic hydroxyl group, that is, a phenolic compound can be used. For example, phenol, o-cresol,
p-cresol, p-ethylphenol, t-butylphenol, 2,6-di-t-butyl-4-methylphenol, nonylphenol, dodecylphenol, styrenated phenol, 2-2'-methylene-bis (4-methyl- 6-t-butylphenol), α-naphthol, β
-Naphthol, hydroquinone monomethyl ether, guaiacol, eugenol, p-chlorophenol, p
-Promophenol, o-chlorophenol, o-Promophenol, 2,4,6-trichlorophenol, o
-Phenylphenol, p-phenylphenol, p-
(P-chlorophenyl) phenol, o- (o-chlorophenyl) phenol, salicylic acid, ethyl p-oxybenzoate, propyl p-oxybenzoate, octyl p-oxybenzoate, dodecyl p-oxybenzoate, catechol, hydroquinone, Resorcin, 3-methylcatechol, 3-isopropylcatechol, pt-butylcatechol, 2,5-di-t-butylhydroquinone, 4,
4'-methylenediphenol, bisphenol A, 1,
2-dioxynaphthalene, 2,3-dioxynaphthalene, chlorcatechol, bromocatechol, 2,4-dihydroxybenzophenone, phenolphthalene, o-
Cresolphthalein, methyl protocatechuate, ethyl protocatechuate, propyl protocatechuate, octyl protocatechuate, dodecyl protocatechuate, pyrogallol, oxyhydroquinone, phloroglucin, 2,4,6-trioxymethyl benzene,
2,3,4-trioxyethylbenzene, methyl gallate, ethyl gallate, propyl gallate, butyl gallate, hexyl gallate, octyl gallate, dodecyl gallate, cetyl gallate, sterial gallate, 2,
Examples of the phenolic compound include 3,5-trioxynaphthalene, tannic acid, and phenol resin.

As the binder resin, an oil-soluble resin such as xylene resin, phenol resin, coumarone resin, vinyltoluene resin, terpene resin, vinyltoluene / butadiene copolymer resin, vinyltoluene / acrylate copolymer resin, or polyvinyl alcohol resin. Water-soluble resins such as methyl cellulose resin, hydroxyethyl cellulose resin, carboxymethyl cellulose resin, methyl vinyl ether / maleic anhydride copolymer resin, polyacrylic acid resin, gelatin and gum arabic can be used, but they are applied as a paint. At this time, it is preferable to use an oil-soluble resin that can be easily dried.

To form the thermosensitive coloring layer 4 using the above-mentioned components, 10 to 15% by weight of a leuco dye and 10 of an acid developer are used.
.About.15% by weight, binder resin 10 to 20% by weight, and an organic solvent which dissolves at least the binder resin among the above components and dissolves only one of the leuco dye and the acid developer, or neither of them. The coating material may be dissolved or dispersed with water to form a coating material, and the resulting coating material may be provided on the entire surface or in a pattern of a substrate by a known printing method or coating method. 5
It is about 15 μm.

The protective layer 5 can be formed by laminating a synthetic resin film, by the extrusion-diene coating method, or by coating a synthetic resin coating. As the synthetic resin forming the protective layer, the same synthetic resins as those used in forming the colored layer can be widely used in consideration of the application or the adhesiveness with other layers. In particular, use of a thermosetting synthetic resin is advantageous in terms of surface hardness and prevention of contamination. In the present invention, however, it is possible to form a protective layer using a coating material composed of an ultraviolet curing resin. preferable. That is, with the ultraviolet curable resin, it is possible to instantaneously cure the composition constituting the protective layer after application, and it is possible to suppress the generation of heat that causes color development of the thermosensitive recording layer. Particularly preferred in the present invention. Further, in the present invention, the surface can be made releasable (releasing property) by adding silicone or the like to the protective layer. The protective layer in the present invention is advantageous in preventing deterioration due to recording due to contact of the thermal head with the thermal recording layer or increase in the number of writing / reading due to contact of the magnetic head with the magnetic recording layer, Further, it is also effective against the act of forging by dissolving the information on the heat-sensitive recording layer using a solvent or the like (improvement of solvent resistance).

The anchor coat layer 6 is a well-known anchor coat layer coating material that is appropriately selected in consideration of the properties of the binder resin forming the magnetic recording layer 3 and the binder resin forming the thermosensitive coloring layer 4. It can be formed by a coating method. As the binder resin used in the anchor coat layer, polyester resin, vinyl chloride / vinyl acetate copolymer resin, polyurethane resin, polyvinyl butyral resin, acrylic resin, cellulose resin, styrene / maleic acid copolymer resin, rubber resin, poly Vinylidene chloride resin, polyamide resin, etc. may be used.

The anchor coat layer 6 plays a role of increasing the adhesion between the magnetic recording layer 3 and the thermosensitive coloring layer 4, and can effectively prevent the thermosensitive coloring layer 4 from peeling off. Further, since the adhesion between the magnetic recording layer 3 and the thermosensitive coloring layer 4 becomes strong, it is also effective in preventing peeling of the thermosensitive recording layer for the purpose of forgery. Furthermore, when the surface of the magnetic recording layer is relatively rough, the anchor coat layer can smooth the surface and print well on the heat-sensitive recording layer as an upper layer, and also the OCR, bar code, etc. There is an advantage that it can be performed more accurately when performing mechanical reading.

Further, when the anchor coat layer 6 is provided, the adhesion between the magnetic recording layer 3 and the thermosensitive coloring layer 4 is sufficiently enhanced, so that the surface of the magnetic recording layer 3 is prevented from being contaminated. Alternatively, some peeling property can be imparted to prevent scratching. When the anchor coat layer 6 is made of a paint as described above, a concealing effect for concealing the color of the magnetic recording layer 3 can also be obtained.

The magnetic information is recorded in the magnetic recording layer 3 by a usual method such as a magnetic head. On the other hand, visible information such as barcode, OCR characters, name, expiration date,
It is recorded by causing a chemical change in the thermosensitive color developing agent by a heating means such as a thermal head or a hot stamp.

When recording magnetic information and visible information,
You may record in the order of visible information and then magnetic information,
Alternatively, the magnetic information and the visible information may be recorded in this order. However, since the heating means is used to record the visible information, if the temperature of the magnetic recording layer may be higher than the Curie temperature when recording the visible information, the visible information is first recorded, and then the magnetic information is recorded. Is preferably recorded.

[0038]

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

In the following examples, all "parts" are parts by weight unless otherwise specified. Example 1 A magnetic coating composition was used in which γ-Fe ₂ O ₃ powder was dispersed in a binder solution composed of vinyl chloride / vinyl acetate and a urethane-based resin over the entire surface of polyethylene terephthalate having a thickness of 188 μm. A micron magnetic recording layer was formed. Next, on the entire surface of this magnetic recording layer, the composition No. 1 for the thermosensitive coloring layer having the following composition was formed. 1 and No. No. 2 composition for heat-sensitive color forming layer prepared by mixing A thermosensitive color developing layer was formed in the following manner using No. 3. Composition No. for thermosensitive coloring layer 1 Fluoran-based leuco dye 20 parts (Hodogaya Chemical Co., Ltd., TH106) Polymethylmethacrylate resin 20 parts (Rohm and Haas Co., Paraloid A-11) Toluene 60 parts Composition for thermosensitive color developing layer No. 1 2,2,4-dihydroxybenzoic acid 20 parts Polymethylmethacrylate resin 20 parts (Rohm and Haas Company's Paraloid A-11) Toluene 60 parts The composition for thermosensitive coloring layer No. 1 and No. No. 2 puts each component into a stirrer equipped with glass beads, and 1
It was prepared by time-dispersive mixing. Next, the composition No. for the thermosensitive color developing layer was used. No. 3 is the above composition No. 1 and N
o. No. 2 1: No. It was prepared by stirring with a propeller mixer at a ratio of 2 = 1: 2.

Then, the composition No. for the thermosensitive coloring layer was prepared. No. 3 was coated on the magnetic recording layer so that the coating amount when dried was 5 g / m ^2, and then dried to manufacture the thermosensitive magnetic recording medium according to the present invention.

Bar code, OCR characters, Chinese characters, Roman characters, etc. were printed on this thermal recording medium with a thick film type thermal head at an applied energy density of 30 mJ / mm ² , and a desired pattern was formed on the recording medium. It was The bar code and OCR characters were clear enough to be read by a machine.

Next, when magnetic recording was carried out on this printed recording medium by a magnetic head, the reproduction output was not affected by the printing. Example 2 Piakent paper having a basis weight of 230 g / cm ² was used instead of polyethylene terephthalate, and the composition No. 1 for the thermosensitive color developing layer was used. 1
As a fluoran-based leuco dye by Shin Nisso Kako
150 was used as the polymethylmethacrylate resin, and DIANAL BR-80 manufactured by Mitsubishi Rayon Co., Ltd. was used. A thermosensitive magnetic recording medium was produced in the same manner as in Example 1 except that gallic acid was used instead of 2,4-dihydroxybenzoic acid of 2.

Barcodes, OCR characters and the like were printed on the thermosensitive magnetic recording medium thus obtained with a thick film type thermal head, and a desired pattern was formed on the recording medium. The bar code and OCR characters were clear enough to be read by a machine.

Then, when magnetic recording was performed on this printed recording medium with a magnetic head, the reproduction output was not affected by the printing.

[0045]

The thermosensitive magnetic recording medium according to the present invention has the following effects because it has the magnetic recording layer and the thermosensitive recording layer from the thermosensitive coloring layer in this order and on the entire surface.

A) Both magnetic information and visible information can be recorded on the recording medium, and moreover, they can be recorded over the entire surface, and a large amount of information can be recorded.

B) In addition to magnetic information, individual visible information corresponding to each situation can be easily recorded, and the visible information area can be freely set.

C) Since the thermosensitive coloring layer is integrally provided on the magnetic recording layer, it is difficult to forge or alter the recording medium as compared with the recording medium having only the magnetic recording layer.

D) Since magnetic information and visible information such as bar code, OCR character, name and expiration date can be recorded on the recording medium, double check of magnetic check and mechanical read check becomes possible. It is difficult to forge / alter the recording medium.

E) In the recording medium according to the present invention, since the magnetic recording layer and the thermosensitive coloring layer are formed in this order on the entire surface of the substrate, the manufacturing process and the formation of the layer thickness of each layer are facilitated.

[Brief description of drawings]

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

FIG. 2 is a sectional view of a thermosensitive magnetic recording medium according to the present invention.

FIG. 3 is a sectional view of a thermosensitive magnetic recording medium according to the present invention.

FIG. 4 is a sectional view of a thermosensitive magnetic recording medium according to the present invention.

[Explanation of Codes] 1 recording medium 2 substrate 3 magnetic recording layer 4 thermosensitive coloring layer 5 protective layer 6 anchor coat layer

Claims (2)

[Claims] 1. A magnetic recording layer is provided on the entire surface of a substrate, and a thermosensitive coloring layer is provided as a thermosensitive recording layer via an anchor coat layer on the entire surface of the magnetic recording layer, and the thermosensitive coloring layer is further protected. A thermosensitive magnetic recording medium comprising a layer. 2. The thermosensitive magnetic recording medium according to claim 1, wherein the magnetic recording layer is a thin film of a metal or an alloy thereof.