JP2742108B2 - Thermosensitive magnetic recording medium and its authenticity determination system - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a thermosensitive magnetic recording medium having a magnetic recording layer and a thermosensitive coloring layer for thermosensitive recording.

INDUSTRIAL APPLICABILITY The present invention can be effectively applied, for example, to display the contents corresponding to the magnetic recording contents of a prepaid magnetic card such as a telephone card or a coupon by thermal recording so that the magnetic recording contents can be visually recognized. It is suitable for making it difficult.

[Problems to be Solved by Conventional Techniques and Inventions] Magnetic recording cards are widely used as portable and useful cards. The card is obtained by forming a magnetic recording layer in a desired region on the surface of a card substrate having an appropriate thickness.

By the way, the magnetic recording card cannot visually check the magnetic recording information such as the progress of use and the balance. For this reason, in the prepaid magnetic recording card, the balance is indicated by a punch hole or the like as a guide. Is not displayed, cash or a magnetic recording card must be replenished and added when the balance is insufficient. As a measure for avoiding such a situation, the use progress, balance, and the like may be displayed on the card surface.

Such display on the card surface can be performed, for example, by forming a thermosensitive coloring layer on the surface of the card opposite to the magnetic recording layer and scanning the thermal coloring layer with a thermal head. Examples of the magnetic card capable of thermally recording include those disclosed in JP-A-52-4297 and JP-A-61-237186.

By the way, such prepaid cards having a certain monetary value tend to be counterfeited, and prevention of counterfeiting is a major technical problem with the cards.

The present invention has been made in view of the above technical problems, and has as its object to provide a thermosensitive magnetic recording medium that is difficult to forge.

Another object of the present invention is to provide such a system for determining the authenticity of a thermosensitive magnetic recording medium.

[Means for Solving the Problems] According to the present invention, the object as described above has a magnetic recording layer and a thermosensitive coloring layer, and a partial area of the thermosensitive coloring layer is made difficult to develop coloring. The thermosensitive magnetic recording medium is characterized in that information on the position of the hardly colored area is recorded on the magnetic recording layer.

In the thermosensitive magnetic recording medium of the present invention, a thermosensitive coloring layer containing a leuco dye, an acidic developer and a binder resin can be used, and the glass transition point of the melting point of the developer of the thermosensitive coloring layer or lower can be used. The thermosensitive coloring layer can be made difficult to develop coloring by being laminated with the resin layer having the coloring layer.

Further, according to the present invention, the object as described above is to obtain information on the position of the hardly-colorable area of the thermosensitive coloring layer by reading the magnetic information of the thermosensitive magnetic recording medium of the present invention, and based on the position information, Attempt thermal recording, detect the presence or absence of coloring, determine that the thermosensitive magnetic recording medium is true if there is no coloring, and determine that the thermosensitive magnetic recording medium is false if there is coloring. A system for determining the authenticity of a thermosensitive magnetic recording medium, characterized in that:

EXAMPLES Hereinafter, specific examples of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic plan view showing a first embodiment of the thermosensitive magnetic recording medium of the present invention, and FIG. 2 is a schematic sectional view taken along the line II-II.

In FIGS. 1 and 2, 2 is a base material, 4 is a magnetic recording layer, 6 is a concealing layer, 8, 8 'is a thermosensitive coloring layer, and 9, 9' is a thermosensitive coloring layer. Are the color formation preventing layers provided in a part of the area, 10, 10 'are printing layers, and 12, 12' are protective layers.

As the base material 2, for example, a synthetic resin sheet such as polyethylene terephthalate, polyacetate, polystyrene, polyvinyl chloride, and polycarbonate, or synthetic paper can be used. The substrate 2 can have, for example, a card shape or any other appropriate shape.

As the magnetic recording layer 4, one generally used as a magnetic recording layer in a conventional magnetic recording medium can be used. For example, Ba-ferrite, Sr-ferrite, Co-coated γ-ferrite, γ-Fe ₂ O ₃ , acicular iron powder, CrO ₂ having a particle size of 10 μm or less, preferably 0.01 to 5 μm, Generally used polyester resins, alkyd resins, vinyl resins, polyurethane resins, or mixed resins thereof can be used. The mixing ratio between the binder resin and the magnetic material is appropriately set in consideration of the adhesiveness to the substrate, the coating film strength, the voltage detected by the magnetic head, and the like.
A range of / 10 is possible, preferably 1/2 to 1/8.
The magnetic recording layer 4 contains other various additives such as a surfactant, a dispersant, a plasticizer, and a lubricant. The thickness of the magnetic recording layer 4 is, for example, about 10 to 15 μm.

The concealing layer 6 has a color that visually conceals the color of the magnetic recording layer 4 and gives a sufficient contrast to the color of the thermosensitive coloring layer 8. The concealing layer 6
A material which is stable under heat-sensitive recording conditions, has sufficient durability even when thin, and can prevent migration of the constituent material of the magnetic recording layer 4 to the heat-sensitive coloring layer 8 can be used. As such a heat-resistant material, a thermosetting resin, for example, a polyamide resin, an epoxy resin, an acrylic resin, a phenol resin, an unsaturated polyester resin, a polyurethane resin, a diallyl phthalate resin, or the like can be used, and a concealing property can be imparted thereto. Pigments such as Al, Sn, Pb, Zn, Cu, Ag, Cu-Zn
And an appropriate amount of a metal oxide such as AlO ₂ or TiO ₂ .

As the concealing layer 6, a non-magnetic metal layer such as Al, Sn, Pb, Ag, Bi, Se, Te, In, Cd besides the above-mentioned thermosetting resin.
Alternatively, an oxide layer of these metals can be used.

The thickness of the concealing layer 6 is, for example, about 0.5 to 2 μm.

As the thermosensitive coloring layers 8, 8 ', those containing a leuco dye, an acidic developer and a binder resin can be used.

As the leuco dye in the thermosensitive coloring layers 8, 8 ',
Crystal violet lactone, triphenylmethane type such as malachite green lactone, fluoran type such as 1,2-benzo-6-diethylaminofluoran, auramine type such as N-benzoyl auramine, and other phenothiazine type And spiropyran-based ones.

As the acidic developer in the thermosensitive coloring layers 8, 8 ',
A compound having a phenolic hydroxyl group, that is, a phenolic compound can be used. As such, for example, phenol, o-cresol, p-cresol, p-cresol
-Ethylphenol, t-butylphenol, 2,6-di-t-butyl-4-methylphenol, nonylphenol, dodecylphenol, styrenated phenol,
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, p-oxybenzoic acid Dodecyl, 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, chlorocatechol, bromocatechol, 2,4-dihydrocybenzophenone, phenolphthalein, o-cresolphthalein, methyl protocatechuate, ethyl protocatechuate, Protocatechuate propyl, protocatechu Octyl acid, dodecyl protocatechuate, pyrogallol, oxyhydroquinone, phloroglucin, 2,4,6-trioxymethylbenzene, 2,3,4-trioxyethylbenzene, methyl gallate, ethyl gallate, propyl gallate , Butyl gallate, hexyl gallate, octyl gallate, dodecyl gallate, cetyl gallate, stearyl gallate, 2,3,5
-Trioxynaphthalene, tannic acid, phenolic resin and the like.

As the binder resin in the thermosensitive coloring layers 8, 8 ', alkyd resins, vinyl chloride resins, urethane resins,
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, polyvinyl alcohol resin, methyl cellulose resin, hydroxyethyl cellulose resin Water-soluble resins such as carboxymethylcellulose resin, methyl vinyl ether / maleic anhydride copolymer resin, polyacrylic acid resin, gelatin and gum arabic can be used.

In the thermosensitive coloring layer, the ratio between the leuco dye and the acid developer is, for example, 1: 0.5 to 1: 3 (equivalent), and the ratio between the binder resin and the (leuco dye + acid developer) is, for example, 1: 0.
It is 1 to 1: 3 (weight).

The thickness of the thermosensitive coloring layers 8, 8 'is, for example, 2 to 10 μm.
m.

A resin having a glass transition point equal to or lower than the melting point of the developer in the thermosensitive coloring layer can be used as the coloring prevention layer 9, 9 '. Such a resin can be appropriately selected from, for example, an acrylic resin, a polyurethane resin, a polyester resin, a polyethylene resin, a polystyrene resin, a polyvinyl chloride resin and the like in consideration of the melting point of the developer used.

The coloring prevention layer 9 is formed in contact with the concealing layer 6, and the coloring prevention layer 9 ′ is formed in contact with the base material 2. Color blocking layer 9, 9 'is not a card entirely provided only in certain regions, color-blocking layer 9, as shown in Figure 1, in certain regions R _1, R ₂ Only provided. The same applies to the color formation preventing layer 9 '.

The thickness of the above color formation preventing layers 9, 9 'is, for example, 0.1 to 3 .mu.m.
m, which is thinner than the thermosensitive coloring layers 8, 8 '. Then, by forming the heat-sensitive recording layer after the formation of the color-blocking layer, the outer surfaces of the heat-sensitive recording layers 8, 8 'can be made sufficiently flat, and the appearance cannot confirm the presence of the color-blocking layer. . The coloring prevention layers 9, 9 'can be formed by, for example, offset printing, gravure printing, silk screen printing, or the like.

As the printing layers 10, 10 ', those used in conventional magnetic recording media and the like, for example, offset printing layers, gravure printing layers, silk screen printing layers, and the like can be used. The thickness of the printing layers 10, 10 'is, for example, 2 to 4
It is about μm.

As the protective layers 12, 12 ', those used as protective layers or wear-resistant layers in conventional magnetic recording media and the like,
For example, a cellulose resin, a urethane resin, a polyester resin, an alkyd resin, a vinyl resin, an epoxy resin, an acrylic resin, or the like can be used. Oleyl amide, stearyl amide, silicone or the like can be added to these resins to impart lubrication. In addition, in order to reduce the amount of the solvent used, an ultraviolet curable resin or an electron beam curable resin can be used. As the ultraviolet curable resin, acrylic, epoxy, or polyester resin is used. be able to.

The thickness of the protective layers 12, 12 'as described above is, for example, 10 μm
Or less, preferably about 1 to 5 μm.

In the magnetic recording / reproducing of the thermosensitive magnetic recording medium of this embodiment, the magnetic head is brought into contact with the protective layer 12. However, in order not to increase the distance between the magnetic head and the magnetic recording layer 4, the magnetic head is protected from the concealing layer 6. It is preferable that the total thickness up to the layer 12 is 10 μm or less.

As described above, the thermosensitive coloring layers 8, 8 'of the present embodiment develop colors by heating with a normal amount of heat in areas other than the areas where the coloring prevention layers 9, 9' are located. With the same amount of heat, the color formation preventing layer undergoes a state change before reaching the melting point of the color developer, so that the amount of heat is deprived, so that substantially no color is formed.

Next, a specific example of manufacturing the thermosensitive magnetic recording medium according to the present invention will be described below. Here, the substrate 2 shown in FIG. 2 and a portion above the substrate 2 were manufactured.

Ba-ferrite magnetic powder is dispersed on one side of a base material 2 made of a white polyethylene terephthalate film having a thickness of 188 μm in a binder melt comprising a vinyl chloride / vinyl acetate copolymer resin, a urethane resin, and an isocyanate-based curing agent. Apply magnetic paint and dry to a thickness of 10
A μm magnetic recording layer 4 was formed.

Next, a coating having the following composition was sufficiently stirred on the magnetic recording layer 4 with a high-speed propeller stirrer, applied and dried to form a 1 μm-thick concealing layer 6.

(A) A1 powder paste [MR-9000 manufactured by Asahi Kasei Co., Ltd.] 100 parts by weight Acrylic resin 150 parts by weight Curing agent 10 parts by weight Toluene 600 parts by weight Methyl ethyl ketone 100 parts by weight Next, a coating material having the following composition is sufficiently stirred on the concealing layer 6 with a high-speed propeller stirrer, applied and dried to a thickness of 1
A μm color blocking layer 9 was formed.

(A) Acrylic resin (glass transition point: 90 ° C) 10 parts by weight Methyl ethyl ketone 60 parts by weight Cyclohexanone 30 parts by weight After sufficiently dispersing each of the paints a and b, the mixture was mixed, sufficiently stirred with a high-speed propeller stirrer, applied and dried to form a thermosensitive coloring layer 8 having a thickness of 3 μm.

(A) Leuco dye [Papyrol SD-120 manufactured by Showa Denko KK] 100 parts by weight Polymethyl methacrylate 50 parts by weight Toluene 500 parts by weight (b) Acid microscope Coloring agent [Papyrol SD-180 manufactured by Showa Denko KK] (Melting point: 180 ° C) 100 parts by weight Polymethyl methacrylate 50 parts by weight Toluene 500 parts by weight On the thermosensitive coloring layer 8, an ultraviolet curable dye was applied and dried to form a protective layer 10 having a thickness of 1 μm.

 Thus, a card-shaped thermosensitive magnetic recording medium was obtained.

When forming the concealing layer 6, a card-like thermosensitive magnetic recording medium was obtained in the same manner using the following paint.

(B) A1 powder paste [MR-9000 manufactured by Asahi Kasei Corporation] 100 parts by weight Urethane resin 120 parts by weight Curing agent 20 parts by weight Methyl isobutyl ketone 200 parts by weight Toluene 300 parts by weight Cyclohexanone 100 parts by weight (C) TiO ₂ 200 parts by weight Acrylic resin 100 parts by weight Curing agent ... 10 parts by weight Toluene ... 600 parts by weight Methyl ethyl ketone ... 100 parts by weight (D) Cu-Zn paste ... 120 parts by weight Urethane resin ... 120 parts by weight 20 parts by weight Methyl isobutyl ketone 200 parts by weight Toluene 300 parts by weight cyclohexanone 100 parts by weight Was used to obtain a card-shaped thermosensitive magnetic recording medium in the same manner.

(B) Polyurethane resin (glass transition point: 107 ° C) ···· 10 parts by weight Methyl ethyl ketone ··· 60 parts by weight Cyclohexanone ··· 30 parts by weight (c) Polyester resin (glass transition point: 60) ℃) ··· 10 parts by weight Methyl ethyl ketone ··· 60 parts by weight Cyclohexanone ··· 30 parts by weight (d) Polyvinyl chloride resin (glass transition point: 83 ° C) ··· 10 parts by weight Methyl ethyl ketone 60 parts by weight Cyclohexanone 30 parts by weight A block heated to 130 ° C. is pressed at 200 g / cm ² for 5 seconds against the recording medium manufactured as described above to form a thermosensitive coloring layer. The color was developed, and the color was measured with a Mabes reflection densitometer RD-514 (according to Cyberne standard). The resulting color density values are shown in Table 1 below.

Note that the background density is 0.31 to 0.33, and as can be seen from Table 1, there is almost no color development in the presence of the color formation preventing layer.

FIG. 3 is a schematic sectional view showing a second embodiment of the thermosensitive magnetic recording medium of the present invention. In this drawing, the same members as those in FIG. 2 are denoted by the same reference numerals.

The present embodiment is an example in which a thermosensitive coloring layer and a coloring prevention layer are provided only on the side of the substrate 2 opposite to the magnetic recording layer 4 side.

FIG. 4 is a block diagram showing a schematic configuration of an apparatus used for recording / reproducing the thermosensitive magnetic recording medium of the present invention as described above, and FIG. 5 performs the authenticity judgment using the apparatus. FIG. 6 is an explanatory diagram of the situation, and FIG. 6 is a flowchart at that time.
Hereinafter, an example of the authenticity determination will be described with reference to these drawings.

First, as shown in FIG. 5 (a), a coupon (card) 20 as a thermosensitive magnetic recording medium is inserted into the insertion slot 22 in the direction of the arrow (S1). In the magnetic recording layer of the card, information such as the type of the card, the balance, and the positions of the hardly-colored areas R ₁ and R ₂ are recorded. The hardly-colored area is provided at a predetermined position determined according to the type of the card along the first long side (upper side in FIG. 5) of the card. Then, the number of used times (these are equivalent to the used amount) is thermosensitively recorded along the second long side (the lower side in FIG. 5) of the card. Two used marks M ₁ and M ₂ corresponding to the used times
Are formed.

Next, as shown in FIG. 5 (b), the reproducing magnetic head is moved while moving the inserted card in the direction of the arrow.
Magnetic recording information is read from the magnetic recording layer using MH1, and stored in the memory M (S2).

Next, it is determined whether there is an error in the magnetic information stored in the memory M (S3). At the time of this determination, the criterion information can be supplied from the main control device C to the CPU.
Alternatively, the criterion information may be stored in the memory M in advance.

In the case of the determination of no error in S3, next, FIG. 5 (c)
As shown in (4), while moving the card in the direction of the arrow, the thermal head TH1 is used to heat the position according to the difficult-to-color-developing area position information stored in the memory M to try to develop color (S4). . The heating at this time is performed with an amount of heat that does not cause color development in the hardly colorable region and causes color development in other regions.

Next, as shown in FIG. 5 (d), while moving the card in the direction of the arrow, it is determined whether or not the heated hardly-colored area position is colored using the optical sensor S1 (S5). ). Here, there is no coloring when there is a difficult coloring region at a regular position.

In the case of the determination of no color development in S5, as shown in FIG. 5 (e), while moving the card in the direction of the arrow, the (used number of times + 1) -th is used by using the optical sensor S2. It is determined whether or not the area where the used mark should be formed this time is colored (S6).

In the case of the determination of no color development in S5, as shown in FIG. 5 (f), the card is moved in the direction of the arrow while using the thermal head TH2 (the number of used times + 1).
The second used mark forming area is heated (S7). The heating at this time is performed in the same amount as the heating in S4.

Next, as shown in FIG. 5 (g), while moving the card in the direction of the arrow, the (used number of times + 1) th used mark forming area is colored using the optical sensor S3. and it determines whether or not the mark M ₃ is formed (S
8).

If it is determined that there is color development in S8, then, as shown in FIG. 5 (h), while moving the card in the direction of the arrow, the recording magnetic head MH2 is used to apply the current time to the magnetic recording layer. Prescribed information on use (update of date, number of times used, etc.)
Is recorded (S9).

Thereafter, as shown in FIG. 5 (i), the card 20 is ejected from the ejection port 24 in the direction of the arrow (S10).

In addition, in the case of determining that there is an error in S3, in the case of determining that there is color in S5, in the case of determining that there is color in S6, and in the case of determining that there is no color in S8, the card is all valid. (S1)
1) The card is discharged from a discharge port different from the discharge port in the case of S10 (S12).

The card-like thermosensitive magnetic recording medium according to the present invention as described above can also be used as a prepaid card other than a coupon card. In this case, the heat-sensitive record is a record of the use of the card (date and fee, etc.) and the details of the balance. It is effectively applied to printing. That is, the user can always know the contents of the card by correcting the balance amount recorded on the magnetic recording layer each time the card is used, and printing the details by thermal recording on the surface of the card.

[Effects of the Invention] According to the present invention as described above, the thermosensitive coloring layer of the thermosensitive magnetic recording medium is provided with the hardly coloring region, and the information on the position of the hardly coloring region is magnetically recorded. It is possible to easily and accurately determine the authenticity by detecting whether or not the hardly-colored area exists at the regular position when the medium is used. Further, in the thermosensitive magnetic recording medium of the present invention, since the hardly-colored area can be made invisible in appearance, the existence of the authenticity determination system of the present invention is generally unknown. Further, even if the presence of the hardly-colored area is known, it is extremely difficult to form the magnetically-recorded area at a regular position where magnetic recording is performed.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing a first embodiment of the thermosensitive magnetic recording medium of the present invention, and FIG. 2 is a schematic sectional view taken along the line II-II. FIG. 3 is a schematic sectional view showing a second embodiment of the thermosensitive magnetic recording medium of the present invention. FIG. 4 is a block diagram showing a schematic configuration of an apparatus used for recording / reproducing a thermosensitive magnetic recording medium according to the present invention. FIG. FIG. 6 is a flowchart at that time. 2: Base material, 4: Magnetic recording layer, 6: Hiding layer, 8,8 ': Thermosensitive coloring layer, 9,9': Color blocking layer, 10,10 ': Printing layer, 12,12': Protecting layer, R ₁ , R ₂ : Difficult coloring area.

Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI G06K 17/00 G07F 7/08 C G07F 7/12 G06F 15/30 330

Claims (4)

(57) [Claims] A magnetic recording layer and a heat-sensitive coloring layer, wherein a part of the heat-sensitive coloring layer is hardly colored; information on the position of the hard-colored area is recorded on the magnetic recording layer; A thermosensitive magnetic recording medium, characterized in that: 2. The thermosensitive magnetic recording medium according to claim 1, wherein the thermosensitive coloring layer comprises a leuco dye, an acidic developer, and a binder resin. 3. The thermosensitive magnetic recording medium according to claim 2, wherein the thermosensitive coloring layer is hardly colored by being laminated with a resin layer having a glass transition point equal to or lower than the melting point of the developer of the thermosensitive coloring layer. 4. The thermosensitive magnetic recording medium according to claim 1, wherein the magnetic information is read to obtain information on the position of the hardly-colored area of the thermosensitive coloring layer, and the thermosensitive recording of the hardly-colored area is performed based on the position information. Detecting the presence or absence of coloring, determining that the thermosensitive magnetic recording medium is true if there is no coloring, and determining that the thermosensitive magnetic recording medium is false if there is coloring. A true / false determination system for a thermosensitive magnetic recording medium.