JP2757905B2 - Thermal magnetic recording media - Google Patents

Description

Description: 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. 2. Description of the Related Art Magnetic recording media in which a magnetic recording layer is provided on the surface of a substrate such as plastic are known as credit cards, cash cards, ID cards, tickets, and commuter passes. , Magnetic tapes and the like. Such a magnetic recording medium has the advantage that the recording density is high and the recorded information cannot be easily read from the outside. May need to record visible information. In such a case, characters, designs, and the like have been printed on a margin or the back surface of the base surface of the magnetic recording medium. However, since the magnetic recording medium is generally small in size, necessary characters are printed. There is a shortage of space for printing visible information such as the information, and there is a disadvantage that a sufficient amount of information cannot be printed. For this reason, magnetic recording media in which visible information such as characters and designs are formed on a magnetic recording layer of a magnetic recording medium by printing means have recently emerged. However, since the visible information is formed by various printing means, there is a disadvantage that the content is uniform and fixed and the change is poor. In addition, for example, bar codes, OCR characters, names,
Printing individual information such as the expiration date has a drawback that it is not feasible because it increases manufacturing costs. For this reason, it has been proposed to provide a heat-sensitive coloring layer for recording visible information by coloring with a heating means. However, the heat-sensitive coloring layer which has conventionally been often formed in a band shape has been proposed. Forming a color-forming layer requires a technique to make the surface uniform in the heat-sensitive color-forming layer, in which the surface smoothness greatly affects printing sensitivity, and therefore, the manufacturing process becomes complicated and the cost is high. There was a problem of becoming. As other forms, it has been proposed to provide a magnetic recording layer and a heat-sensitive recording layer on the same plane, or to provide a magnetic recording layer on a heat-sensitive coloring layer. The process is complicated, and especially when a magnetic recording layer is provided on the heat-sensitive coloring layer, it is necessary to pay attention to the temperature control when forming the magnetic layer so that the heating coloring layer does not inadvertently develop color. However, there is a problem that the selection of a solvent is restricted. [0006] In recent years, forgery or falsification of magnetic recording media such as cash cards, credit cards, commuter passes and the like has become a major social problem, and much research has been conducted on how to prevent forgery / falsification of magnetic recording information. However, at present, a simple and effective method of forging or altering magnetic recording information has not been found yet. The present invention is intended to solve the above-mentioned problems associated with the prior art, 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 on which individual visual information according to each situation can be easily recorded. C) To provide a recording medium in which forgery or falsification of magnetic information cannot be easily performed. D) To provide a recording medium capable of double-checking magnetic information and visible information and difficult to forge and alter. In the 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 coloring layer is formed as a thermosensitive recording layer on the entire surface of the magnetic recording layer. And a protective layer having a surface releasability on the thermosensitive coloring layer.Visible information is recorded by bringing a heating means such as a thermal head into contact with the thermosensitive coloring layer. Is done. Further, in the present invention, if necessary,
An anchor coat layer may be provided between the magnetic recording layer and the thermosensitive coloring layer. Hereinafter, the present invention will be described with reference to preferred embodiments shown in the drawings. As shown in FIG. 1, a thermosensitive magnetic medium 1 according to the present invention comprises a sheet-shaped or plate-shaped substrate 2, a magnetic recording layer 3 provided thereon, and The heat-sensitive coloring layer 4 as the provided heat-sensitive recording layer and the protective layer 5 are provided on the heat-sensitive coloring layer 4, and serve to protect the heat-sensitive coloring layer 4. The magnetic recording layer 3 is provided on the entire surface of the base 2. The thermosensitive coloring layer 4 is provided on the entire surface of the magnetic recording layer 3. Another specific example of the thermosensitive magnetic recording medium 1 according to the present invention is shown in FIGS. However, in FIGS. 2 and 4, the protective layer 5 is omitted. 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 on a base 2 in this order. 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 the front and back surfaces of a base 2, so that a large amount of magnetic information and visible information can be recorded. It has become. In the thermosensitive magnetic recording medium 1 according to the present invention, a magnetic recording layer 3, a thermosensitive coloring layer 4, and if necessary, a protective layer 5 and an anchor coat layer 6 are formed on a substrate 2 by a gravure method or a roll method. And a known coating method such as a knife edge method. In some cases, a transfer laminate in which a thermosensitive coloring layer, a magnetic recording layer, and a hot-melt adhesive layer are laminated on a transfer substrate once via a release layer is prepared, and this laminate is used. 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 by using the method. Further, a lamination laminate in which a magnetic recording layer and a thermosensitive coloring layer are laminated on a lamination substrate is prepared.
The thermosensitive magnetic recording medium according to the present invention can also be manufactured by providing an adhesive layer on the back surface of the laminate and integrally bonding 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. Examples of the substrate 2 include plastics such as nylon, cellulose diacetate, cellulose triacetate, polystyrene, polyethylene, polypropylene, polyester, polyimide, polycarbonate, copper, and aluminum. Such metal, paper, impregnated paper, etc. 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 2 is 0.005 to 0.005.
It is about 5 mm. The magnetic recording layer _{3, 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
l, Ba ferrite, Sr ferrite and other known magnetic fine particles are dispersed in a suitable resin or ink vehicle, and a dispersion is prepared by a conventionally known coating method such as a gravure method, a roll method, or a knife edge method. 2 can be formed. When the magnetic recording layer 3 is formed by such a coating method, its thickness is 1 to 100.
Microns, preferably on the order of 5-20 microns. In this case, as a binder 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 a rubber-based resin such as a nitrile rubber or a urethane elastomer is added as necessary. Also,
In the dispersion obtained by dispersing the magnetic fine particles 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 material having 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 can be formed on the substrate 2 by a vacuum deposition method, a sputtering method, a plating method, or the like. In the present invention, it is particularly preferable to form the magnetic recording layer 3 from a thin film made of the above-mentioned metal or its alloy in order to improve the recording resolution and the reading accuracy of visible information. In the case of the layer configuration of the present invention as described above, since the heat-sensitive recording layer is formed on the magnetic recording layer, the recording resolution of the magnetic recording layer may be reduced. Alternatively, this problem can be solved by forming a thin film made of the alloy. Furthermore, the metal thin film as described above simultaneously becomes a reflection film,
The contrast of the visible information formed on the heat-sensitive recording layer thereover is further increased to make it easier to read, and the OCR
There is an advantage that machine reading of a bar code or the like can be performed with higher accuracy. As described above, the vacuum deposition method, the sputtering method,
When the magnetic recording layer 3 is formed by plating, the film thickness is preferably about 100 Å to 1 μm, preferably about 500 to 2,000 Å. The thermosensitive coloring layer 4 is basically composed of a leuco dye, an acidic developer and a binder resin. Leuco dyes include triphenylmethanes such as crystal violet lactone and malachite green lactone; fluorans such as 1,2-benzo-6-diethylaminofluoran; auramines such as N-benzoyl auramine; and phenothiazines 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
-Bromophenol, o-chlorophenol, o-bromophenol, 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, Resorcinol, 3-methylcatechol, 3-isopropylcatechol, pt-butylcatechol, 2,5-di-tert-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, steryl gallate, 2,
Examples of phenolic compounds include 3,5-trioxynaphthalene, tannic acid, and phenolic resins. Examples of the binder resin include oil-soluble resins such as xylene resin, phenol resin, coumarone resin, vinyl toluene resin, terpene resin, vinyl toluene / butadiene copolymer resin, vinyl toluene / acrylate copolymer resin, and polyvinyl alcohol resin. Water-soluble resins such as methylcellulose resin, hydroxyethylcellulose resin, carboxymethylcellulose resin, methylvinylether / maleic anhydride copolymer resin, polyacrylic acid resin, gelatin, and gum arabic can be used. In this case, it is preferable to use an oil-soluble resin that is easily dried. To form the thermosensitive coloring layer 4 using the above-mentioned components, 10 to 15% by weight of leuco dye and 10% by weight of acidic developer
An organic solvent that dissolves at least the binder resin and dissolves only one of the leuco dye and the acidic developer, or dissolves neither of them, or 15 to 15 wt% of the binder resin, and 10 to 20 wt% of the binder resin. It may be dissolved or dispersed using water to form a coating, and the obtained coating may be provided on the entire surface or in a pattern on a substrate by a known printing method or coating method. 5
〜15 μm. The protective layer 5 can be formed by laminating a synthetic resin film, by an extrude-diene coating method, or by applying a synthetic resin paint. As the synthetic resin constituting the protective layer, those similar to the synthetic resins used for forming the colored layer can be widely used in consideration of the application or the adhesion to other layers. In particular, use of a thermosetting synthetic resin is advantageous in terms of surface hardness and prevention of contamination, but in the present invention, it is particularly preferable to form a protective layer using a coating made of an ultraviolet-curable resin. preferable. That is, according to the ultraviolet-curable resin, the composition after forming the protective layer can be instantaneously cured after application, and the generation of heat that causes coloration of the heat-sensitive recording layer can be suppressed. Particularly preferred in the present invention. In the present invention, silicone or the like is added to the protective layer to make the surface releasable (releasability). The protective layer in the present invention is advantageous in preventing deterioration due to an increase in the number of times of writing / reading due to contact of the thermal head with the thermal recording layer or recording due to contact of the magnetic head with the magnetic recording layer, Further, it is also effective against counterfeiting by dissolving information in the heat-sensitive recording layer using a solvent or the like (improvement in solvent resistance). The anchor coat layer 6 is formed using a well-known paint for the anchor coat layer in consideration of the properties of the binder resin constituting the magnetic recording layer 3 and the binder resin constituting the thermosensitive coloring layer 4. It can be formed by a coating method. As the binder resin used for 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 and the like can be used. The anchor coat layer 6 plays a role in 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 heat-sensitive coloring layer 4 becomes strong, it is also effective in preventing the heat-sensitive recording layer from peeling off 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 thereover. There is an advantage that the reading can be performed with higher accuracy when performing machine reading. When the anchor coat layer 6 is provided, since the adhesion between the magnetic recording layer 3 and the thermosensitive coloring layer 4 is sufficiently enhanced, the surface of the magnetic recording layer 3 is prevented from being contaminated. Alternatively, some releasability for preventing damage can be imparted. 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 barcodes, OCR characters, names,
Recording is performed by causing a chemical change in the thermosensitive coloring agent by a heating means such as a thermal head or a hot stamp. When recording magnetic information and visible information,
First, visible information and then magnetic information may be recorded in this order.
Alternatively, the information may be recorded in the order of magnetic information and then visible information. 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 during the recording of the visible information, the visible information is first recorded, and then the magnetic information is recorded. Is preferably recorded. 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 Using a magnetic coating material 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 thickness of 10 μm was used. A micron magnetic recording layer was formed. Next, a composition for a thermosensitive coloring layer having the following composition was coated on the entire surface of the magnetic recording layer. 1 and No. Composition No. 2 for the thermosensitive coloring layer prepared by mixing Using No. 3, a thermosensitive coloring layer was formed as follows. The composition for the thermosensitive coloring layer No. 1 Fluoran leuco dye 20 parts (TH106, manufactured by Hodogaya Chemical Co., Ltd.) Polymethyl methacrylate resin 20 parts (Paraloid A-11, manufactured by Rohm and Haas Co., Ltd.) Toluene 60 parts Composition for heat-sensitive coloring layer 2 2,4-dihydroxybenzoic acid 20 parts Polymethyl methacrylate resin 20 parts (Rohm and Haas Co., Ltd., Paraloid A-11) Toluene 60 parts 1 and No. In the case of No. 2, each component was put into a stirrer equipped with glass beads, and 1
It was prepared by time-dispersed mixing. Then, the composition for the thermosensitive coloring layer No. No. 3 is the composition No. 1 and N
o. 2 as No. 1: No. It was prepared by stirring with a propeller mixer at a ratio of 2 = 1: 2. Then, the composition for the thermosensitive coloring layer No. 1 was prepared. No. 3 was applied to the magnetic recording layer so that the coating amount upon drying was 5 g / m ^2, and then dried to produce a thermosensitive magnetic recording medium according to the present invention. When a barcode, OCR characters, Chinese characters, Roman characters, and the like were printed on the thermosensitive recording medium with a thick film type thermal head at an applied energy density of 30 mJ / mm ² , a desired pattern was formed on the recording medium. Was. Barcodes and OCR characters were clear enough to be readable by a machine. Next, when the magnetic recording was performed on the printed recording medium by a magnetic head, no influence was observed on the reproduction output of the recording medium. Example 2 Piakent paper having a basis weight of 230 g / cm ² was used in place of polyethylene terephthalate. 1
As a fluoran leuco dye of Nippon Soda Chemical Co., Ltd.
No. 150, and Dianal BR-80 manufactured by Mitsubishi Rayon Co., Ltd. as a polymethyl methacrylate resin. A thermosensitive magnetic recording medium was produced in the same manner as in Example 1, except that gallic acid was used in place of 2,4-dihydroxybenzoic acid. When a bar code, an OCR character, or the like was printed on the thus obtained thermosensitive magnetic recording medium by a thick film type thermal head, a desired pattern was formed on the recording medium. Barcodes and OCR characters were clear enough to be readable by a machine. Next, when magnetic recording was performed on the printed recording medium with a magnetic head, no influence of the printing was observed on the reproduced output. The thermosensitive magnetic recording medium according to the present invention has a magnetic recording layer and a thermosensitive recording layer from a thermosensitive coloring layer in this order and over the entire surface, and thus has the following effects. A) Both the magnetic information and the visible information can be recorded on the recording medium, and can be recorded in a completely overlapping manner, so that a large amount of information can be recorded. B) In addition to magnetic information, individual visible information according to each situation can be easily recorded, and a visible information area can be freely set. C) Since the heat-sensitive coloring layer is integrally provided on the magnetic recording layer, forgery and falsification of the recording medium are more difficult than a recording medium having only the magnetic recording layer. D) Since magnetic information and visible information such as barcodes, OCR characters, names, and expiration dates can be recorded on the recording medium, a magnetic check and a mechanical read check can be double-checked. Also, it is difficult to forge or 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 uniform formation of the thickness of each layer are also facilitated.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a 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. [Description of Signs] 1 Recording medium 2 Base 3 Magnetic recording layer 4 Thermal coloring layer 5 Protective layer 6 Anchor coat layer

   ────────────────────────────────────────────────── ─── Continuation of front page                   (56) References JP-A-52-114333 (JP, A)                 JP-A-52-123633 (JP, A)                 JP-A-53-60205 (JP, A)                 JP-A-56-27394 (JP, A)                 Actual opening 1974-85024 (JP, U)

Claims (1)

(57) [Claims] A surface formed by providing a magnetic recording layer on the entire surface of the substrate, providing a thermosensitive coloring layer as a thermosensitive recording layer on the entire surface of the magnetic recording layer, and further adding silicone to an ultraviolet curable resin on the thermosensitive coloring layer. A thermosensitive magnetic recording medium comprising a protective layer having releasability.