JPH04201596A - Magnetic card - Google Patents

Abstract

PURPOSE:To enable thermal recording and erazing to be performed by a method wherein 16 or more C higher fatty acid and thiodipropionic acid are contained by a weight ratio of 90:10 to 10:90 in organic low molecular substance. CONSTITUTION:Organic low molecular substance 6 to be used in a resin base 7 of a thermal recording layer 5 of a magnetic card contains 16 or more C higher fatty acid and thiodipropionic acid by a weight ratio of 90:10 to 10:90. For instance, palmitic acid, margaric acid, stearic acid, nonadecanoic acid, eicosanic acid, heneicosanic acid, behenic acid, lignoceric acid, pentacosanic acid, etc., are exemplified as the 16 or more C higher fatty acid. Those may be used individually or by mixing two or more kinds. Thereby, information can be recorded on the thermal recording layer 5, and can be added or updated without receiving limitation of an amount of the information due to an area of the magnetic card.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a magnetic layer capable of recording and reproducing magnetic information;
The present invention relates to a magnetic card used as a prepaid card, which has an emotional recording layer that can reversibly display visible information such as characters and images based on temperature changes.

：Conventional technology 2 In recent years, prepaid cards have become popular as a means of payment for fees and charges in fields related to communications such as telephones, transportation with various means of transportation, and distribution such as department stores. Payment methods are becoming more and more popular. The card owner cannot directly know whether the magnetic layer of such a magnetic card records necessary data such as monetary balance.

For this reason, each time a magnetic card is used, a hole is punched in the magnetic card to display the approximate balance.A heat-sensitive coloring layer is provided on the card surface (front side) opposite to the magnetic surface, and the balance is thermally displayed each time a payment is made. A method of printing with a head, or a method of providing a vapor-deposited metal film on a magnetic surface and destroying the metal film with a thermal head to expose the underlying layer for display is adopted.

However, the method of punching holes in magnetic cards to display balances cannot display accurate numbers. Furthermore, since information cannot be rewritten in a magnetic card using a heat-sensitive recording layer or a metal vapor deposition film, the amount of information is limited by the area of the magnetic card.

On the other hand, heat-sensitive recording materials have also been proposed in which information can be recorded or erased reversibly and can be used repeatedly. Such recording materials include polyester, polyamide, polyvinyl chloride, and vinyl chloride.
There are some that have a heat-sensitive recording layer by dispersing organic low-molecular substances such as high alcohol and higher fatty acids in resin such as vinyl acetate copolymer (JP-A-55-154198, JP-A-5
4-119377 and JP-A-2-1363, etc.).

In such materials, images are formed and erased by changing the transparency of the track sensitive layer due to temperature, and images are obtained as transparent images on a white background or as white images on a colorless background.

Problems to be Solved by Two-Layer Clearance However, since the temperature range in which records can be erased is not sufficiently wide in the above-mentioned heat-sensitive recording materials, it is difficult to erase them using a thermal head, a hot stamp, a hot roll, or the like. For this reason, magnetic cards provided with these thermoreversible recording materials have not yet been put into practical use.

An object of the present invention is to provide a magnetic card having a heat-sensitive recording layer that allows heat-sensitive recording and erasing over a wide temperature range.

[Means for Solving the Problems] In order to solve the above problems, the present inventors conducted various studies on materials used for the heat-sensitive recording layer.

As a result, by combining specific materials as organic low-molecular substances used in the resin base material of the heat-sensitive recording layer of magnetic cards, the erasing (transparency) temperature can be raised to a greater extent than that of conventionally known reversible heat-sensitive S2 recording materials. They have discovered that it is possible to shift the temperature to the higher temperature side and expand the transparent temperature range, and have completed the present invention.

The present invention provides a magnetic card having a magnetic layer and a reversible thermosensitive recording layer, the thermosensitive recording layer containing a resin matrix, an organic low molecular substance dispersed in the resin matrix, and a substance that controls crystal growth. The organic low molecular weight substance or at least one type of higher fatty acid having 16 or more carbon atoms, thiodipropionic acid and 9
The present invention provides a magnetic card characterized in that the magnetic card contains the following components in a weight ratio of 0:10 to 10.90.

The magnetic card of the present invention includes a reversible thermosensitive recording layer that can record and erase information such as letters and numbers on the magnetic side or the opposite side, and a magnetic layer that can record and reproduce magnetic information. The thermosensitive recording layer contains a resin base material, a low molecular weight substance, and a crystal growth controlling substance. Next, the present invention will be explained in detail.

(a) Resin base material The resin base material used in the heat-sensitive recording layer of the magnetic card of the present invention is a matrix resin that holds organic low-molecular substances uniformly dispersed and forms two layers, and has a maximum transparency. It has a big impact. Therefore, the resin base material is preferably a resin that is highly transparent, has excellent mechanical stability, and has good film-forming properties. Such resins include polyvinyl chloride: vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-vinyl alcohol copolymer, vinyl chloride-acrylate copolymer, and other vinyl chloride copolymers: polychloride. Vinylidene chloride copolymers such as vinylidene, vinylidene chloride-hinyl chloride copolymer, and vinylidene chloride-acrylonitrile copolymer. Polyester, polyamide, polyacrylate or polymethacrylate or acrylate-methacrylate copolymer, silicone resin, polystyrene, styrene.
Examples include orbital plastic resins such as butadiene copolymers and other thermosetting resins. These base resins can be used alone or in combination of two or more.

(b) Organic low-molecular substance Next, the organic low-molecular substance dispersed in the resin matrix includes at least one type of higher fatty acid having 16 or more carbon atoms;
Thionopropionic acid.

S (CHx CHt COOH)! A combination of these is used. By specifically combining the higher fatty acids with thiodipropionic acid, which has a higher melting point than the higher fatty acids, erasing (transparency) is better than conventionally known reversible thermosensitive recording materials.
The temperature moves to the high temperature side and the transparent temperature region expands.

Specific examples of such higher fatty acids having 16 or more carbon atoms include:
Palmitic acid, margaric acid, stearic acid, nonadecanoic acid, eicosanoic acid, heneicosanoic acid, behenic acid, lignoceric acid, pentacosanoic acid, cerotic acid, heptacanoic acid, montanic acid, nonacosanoic acid, melisic acid, 2-
Hexadecenoic acid, trans-3-hexadenoic acid, 2-
Hebutadenoic acid, trans-2-octadecenoic acid, cis-2-octadecanoic acid, trans-4-octadecenoic acid, cis-6-octadecenoic acid, elaidic acid, basenic acid, trans-bondoinic acid, erucic acid, branic acid,
Ceracoleic acid, trans-ceracoleic acid, trans-8, trans-10-octadecadienoic acid, rhinoelaidic acid, α-eleostearic acid, β-eleostearic acid, pseudoeleostearic acid, 12.20- Examples include heneicosatuenoic acid. These may be used alone or in combination of two or more.

The blending ratio of the higher fatty acid and thiodipropionic acid is preferably in the range of 90:10-10:90 by weight. If the amount of thionopropionic acid is less than the above range, the transparent temperature range will not be sufficient, while if it is more than the above range, the contrast will be significantly reduced.

(c) Crystal Growth Control Substance The crystal growth control substance that is used as one of the organic low-molecular substances of the present invention includes various surfactants. These substances control the crystal growth of the a-molecule low-molecular substance and further expand the transparent temperature range. Specific examples of surfactants used for this purpose include polyhydric alcohol higher fatty acid esters, polyhydric alcohol higher alkyl ethers, polyhydric alkyl ether higher fatty acid esters, higher alcohols, higher alkyl phenols, higher fatty acid higher alkyl amines, and higher fatty acid amides. , lower olefin oxide adduct of fat or oil or polypropylene glycol; acetylene glycol: Na of higher alkyl hanzene sulfonic acid
, Ca%Ba or Mg salt; Ca, Ba or Mg of aromatic carboxylic acid, higher fatty acid sulfonic acid, aromatic sulfonic acid, sulfuric acid monoester or phosphoric acid mono- or no ester
Salt: Low sulfation oil: Poly long chain alkyl acrylate, acrylic oligomer m: Poly long chain alkyl methacrylate: Long chain alkyl methacrylate-amine-containing monomer copolymer; Styrene-maleic anhydride copolymer; Olefin-maleic anhydride Examples include acid copolymers. By incorporating such a surfactant, the heat-sensitive recording material can be used repeatedly, and the temperature range in which it exhibits maximum transparency is expanded.

Other additives that extend the temperature range over which maximum clarity is maintained include tributyl phosphate, tri-2-ethylhexyl phosphate, triphenyl phosphate, tricresyl phosphate,
Butyl oleate, dimethyl phthalate, diethyl phthalate, dibutyl phthalate, dihebutyl phthalate, di-n-octyl phthalate, di-2-ethylhexyl phthalate,
Diisononyl phthalate, dioctyldecyl phthalate, diisodecyl phthalate, butylbenzyl phthalate, dibutyl adipate, di-n-hexyl adipate, no-2-ethylhexyl anopate, alkyl adipate 610
．． Di-2-ethylhexyl azelaate, butyl sebanate, di-2-ethylhexyl sepanate, diethylene glycol henzoate, triethylene glycol-
2-ethyl butylade, butyl acetyl ricinoleate,
Examples include butyl acetyl ricinoleate, butylphthalyl butyl glycolate, tributyl acetyl citrate, and the like.

The blending ratio of these materials is preferably about 1 to 80 parts by weight based on 100 parts by weight of the organic low-molecular substance.

Other additives may be added to the heat-sensitive layer of the recording material of the present invention as long as they do not impair its performance.

(d) Magnetic sheet member The heat-sensitive recording layer is provided on the surface of a conventionally known magnetic sheet member. As such a magnetic sheet member, a conventionally known magnetic notebook in which one side of a base material such as plastic, glass, paper, cloth, or metal is coated with a matrix resin containing a magnetic material may be used. In addition, these magnetic layers may be provided by coating the base material directly or via an undercoat layer, or by coating another base material in advance to form a magnetic layer. may be attached to a base material using an adhesive or a pressure-sensitive adhesive.

The magnetic layer may be formed on the entire surface of the card or on a portion of the card, such as in the form of a stripe.

(e) Formation of heat-sensitive recording layer The preparation liquid used for forming the heat-sensitive recording layer can be prepared by various methods. For example, a mixed solution of the above-mentioned resin base material, organic low-molecular substance, and crystal growth control substance may be prepared, or a solvent that does not dissolve at least one of the organic low-molecular substances may be used to prepare the resin base material. A dispersion may be prepared by preparing a solution, dispersing the organic low-molecular substance in the form of fine particles, and further dissolving a high boiling point solvent.

The blending ratio of the organic low-molecular substance and resin base material in the heat-sensitive layer is 50 to 1 part by weight of the resin base material per 100 parts by weight of the organic low-molecular substance.
About 600 parts by weight is preferable, and 100 to 500 parts by weight is particularly preferable.

When the blending amount of the base material is less than 50 parts by weight and 11 parts, it becomes difficult to stably hold the organic low molecular weight substance in the base material and form an fco film. On the other hand, if the base material exceeds 1,600 parts by weight, the amount of organic low-molecular substances that become cloudy due to substitution is small, making it impossible to read recorded information clearly, making it undesirable as a recording material. The organic low-molecular substance is preferably uniformly dispersed and sufficiently fixed in the base material, and may be partially compatible with the base material.

The solvent used for forming the heat-sensitive recording layer may be selected from various types depending on the base material and the type of organic low-molecular substance, and examples thereof include tetrahydrofuran, methyl ethyl ketone, methyl isobutyl ketone, chloroform, carbon tetrachloride, ethanol, toluene, and hensen. Can be mentioned. Note that in the heat-sensitive layer obtained not only when a dispersion is used but also when a solution is used, the organic low-molecular substance precipitates as fine particles and exists in a dispersed state.

To provide the heat-sensitive recording layer on the magnetic notebook member,
Any known molding method may be used for the polymer used as the resin base material. For example, the prepared solution is applied onto another support such as plastic, glass plate, metal plate, paper, cloth, etc., dried to form a heat-sensitive layer, and this is applied to the magnetic notebook using an adhesive, adhesive, etc. You can also paste it on. Alternatively, the heat-sensitive recording layer may be provided on the magnetic sheet using a variety of coating methods. Each layer, such as a magnetic recording layer, a protective layer, a heat-sensitive recording layer, and an overcoat layer, may be provided directly or indirectly to each other.

The thickness of the heat-sensitive recording layer is preferably 1 to 30 μm; if it is thicker than this, the heat sensitivity will be lowered, and if it is less than 1 μm, the contrast (white turbidity) will be lowered.

Furthermore, if an overcoat layer is provided on the heat-sensitive recording layer for protection against heating devices, durability against repeated printing and erasing is improved.

The overcoat layer is made of an organic material such as silicone, acrylic, or fluorine, or a heat-resistant polymer, or 5101, SiOlMgOSZnO.

TiCL, AQtOlA QN, TatO
Examples include inorganic substances such as s. Such an overcoat layer is formed by a conventional coating method or a vacuum deposition method, and in the case of an organic material, the thickness is 0.05 to 10 μm.
Preferably it is O1-58m. Second, when using an inorganic substance, the thickness is 0.01 to 5 μm, preferably 0.1 to 5 μm.
It is 20 μm.

On the other hand, when a heat-sensitive recording layer is provided on the side opposite to the magnetic recording layer of the magnetic sheet, a 3-30 μm thick heat-sensitive recording layer is applied to the magnetic sheet member. Preferably, the heat-sensitive recording layer is coated on a colored layer such as a known colored pigment, dye, or metal layer, which is provided on the opposite side of the magnetic surface of the magnetic notebook so that the change in cloudiness can be clearly seen. Note that the heat-sensitive recording layer may be formed on a support such as plastic, glass, paper, cloth, metal, etc., and then laminated onto a magnetic sheet member using a known adhesive such as an acrylic resin adhesive. good.

FIG. 1 is a schematic cross-sectional view showing an example of a magnetic card according to the present invention in which a heat-sensitive layer is provided on the magnetic recording layer side of the magnetic card. In FIG. 1, the magnetic card of the present invention includes a magnetic sheet member 3 provided with a magnetic recording layer 2 on one side of a base material 1, and a magnetic recording layer 2 provided on one side of a base material 1.
It consists of a thermosensitive recording layer 5 provided on top of which information can be reversibly recorded and erased. The thermosensitive recording layer 5 contains a resin base material 7, an organic low-molecular substance 6 and a crystal growth control substance dispersed therein. Further above the heat-sensitive recording layer 5, an overcoat layer 8 is provided.

FIG. 2 is a schematic sectional view showing another specific example of the present invention.

In the specific example shown in FIG. 2, the magnetic recording layer 2 is provided on one side of the base material l, and the colored layer 9 is provided on the opposite side of the base material. The thermosensitive recording layer 5 is formed on the colored layer 9, and an overcoat layer 8 is further provided thereon.

As described above, the magnetic card of the present invention has a heat-sensitive recording layer on at least one surface of which information can be reversibly recorded and erased, and the content of the magnetic information is readable and reproducible with the naked eye. It becomes possible to rewrite records and update information.

The magnetic card of the present invention thermoreversibly changes between a transparent state and a cloudy state, making visual recording possible.

When transparent, the crystal particles of the organic low-molecular substance in the resin base material become single crystals, and light incident from one side is transmitted to the other side without being scattered, making it appear transparent. On the other hand, when it is cloudy, the particles of the organic low-molecular-weight substance are composed of polycrystals, which are made up of fine crystals of the organic low-molecular-weight substance, and the individual crystal axes are random, so that the incident light is reflected by the crystals of the organic low-molecular substance particles. It appears white because it is refracted and scattered many times at the interface. Therefore, when an organic low-molecular substance is heated above its melting point and cooled, the crystal particles become polycrystalline and become cloudy; when heated to a certain temperature below its melting point and then cooled, the particles become single crystals and become transparent, making it difficult to form and erase images. It is thought that it can be done.

[Example] Next, the magnetic card of the present invention will be described in more detail with reference to Examples. Note that parts below mean parts by weight.

Example 1 A film of 0.2μ was deposited on the magnetic recording layer of a magnetic sheet by vacuum evaporation method.
An A12 protective film of m was provided. Next, the following composition/composition: parts by weight of behenic acid
o7 thiodiprobionic acid
0.3 Hinyl chloride monoacetate copolymer 25DOP
A solution of 0.2% tetrahydrofuran and 12.0% was applied using a wire bar and dried by heating to provide a heat-sensitive recording layer with a thickness of 8 μm. Next, on top of this, a 0°2 μm A
An overcoat layer of 1 t O3 was formed by the ion blating method.

Example 2 A magnetic card was prepared in the same manner as in Example except that a magnetic overcoat layer was provided on the heat-sensitive recording layer.

A UV-curable overcoat liquid of urethane-based acrylate (manufactured by Dainippon Ink Co., Ltd., V-9005) was applied onto the heat-sensitive layer using a wire bar. After drying by heating, IJ/cli' irradiation was performed using a high-pressure mercury lamp to form a curable overcoat layer with a thickness of 2.0 μm.

Comparative example! A magnetic card was produced in the same manner as in Example I except that a protective film was not provided on the magnetic recording layer.

Comparative Example 2 A magnetic card was produced in the same manner as in Example 1 except that no overcoat layer was provided on the heat-sensitive recording layer.

Comparative Example 3 UV curable overcoat layer (V-90
A magnetic card was produced in the same manner as in Example 1 except that 05) was formed to have a thickness of 8 μm.

Example 3 Composition Part by weight Behenic acid
16thiodibropionic acid
0.4 Vinyl chloride-vinyl acetate copolymer 25DOP
0.2 Acrylic oligomer 0.2
A 0.2 μm colored AQ layer was formed by vacuum deposition on the opposite side of the magnetic surface of a tetrahydrofuran 12.0 magnetic sheet (190 μm thick), and the above solution was applied with a wire bar, heated and dried to form an IO μm thick thermosensitive layer. A recording layer was provided. Then, as in Example 1, 0
．． A magnetic card was produced by forming a 2 μm overcoat layer of AQsOs by an ion blating method.

Example 4 Composition Parts by weight Behenic acid 08 Thiodipropionic acid 0.2 Vinyl chloride-vinyl acetate coelectrolyte 2.5 DOP
0.2 acrylic oligomer
0.2 Tetrahydrofuran 12
．． Example 3 except that the above composition solution was used for the heat-sensitive recording layer.
I created a magnetic card in the same way.

Comparative Example 4 A magnetic card was prepared in the same manner as in Example 3 except that no colored layer was provided.

Comparative Example 5 A magnetic card was prepared in the same manner as in Example 4 except that thiodipropionic acid was not blended in the composition of the heat-sensitive recording layer of Example 4 and behenic acid was used as 1.0 part. Acid 95 parts (CH
t) 1o(COOH)t:) Vinyl monochloride-vinyl acetate copolymer 250 parts DOP
30 parts THF
A magnetic card was prepared in the same manner as in Example 1 except that 1500 parts of the solution was used.

Table 1 Example 1 'o, 7 1.6 18"20.
71.6 20 Comparative example 1 0.8 1.2 10 horns 21
．． 01.22 Example 3 0.6 1.5 22〃4
0.7 1.7 20 Comparative Example 4 0
．． 4 0.6 -” 5 0.7
1.7 41 Noro 0.71.52 Image density 140°C x 0.1 second cloudy part and 50
The transparent area was heated in 1°C increments starting at 1°C and measured using a Macbeth optical reflection densitometer RD-920, and the image density of the maximum transparent area was measured.

Transparent density change width: Contact with a heat stamp (manufactured by Ohakasa Denki Co., Ltd.) heated at 1°C increments from 50°C for 0.1 seconds x 2 kg, and make 12 or more transparent using an optical reflection densitometer. And so.

C Effects of the Invention The magnetic card of the present invention has a heat-sensitive recording layer on at least one side of the magnetic sheet, which allows information to be reversibly recorded and erased, and the magnetic information is readable with the naked eye. be. This magnetic card can perform recording and erasing within a practically sufficient temperature range, and the temperature can be easily controlled. Information can be recorded on and erased from the heat-sensitive recording layer using a heating device such as this single thermal head, and additional writing and updating can be performed without being limited by the amount of information due to the area of the magnetic card.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view showing an example of a magnetic notebook according to the present invention, and FIG. 2 is a schematic cross-sectional view showing another specific example of the magnetic sheet according to the present invention. The main symbols in the figure are as follows. ]・Substrate, 2. Magnetic recording layer, 3. Magnetic sheet member, 5.
Thermosensitive recording layer, 6 organic low molecular substance, 7 resin base material, 8 overcoat layer.

Claims (3)

[Claims] (1) A magnetic card having a magnetic layer and a reversible thermosensitive recording layer, the thermosensitive recording layer containing a resin matrix, an organic low molecular substance dispersed in the resin matrix, and a substance that controls crystal growth, The organic low-molecular substance contains at least one type of higher fatty acid having 16 or more carbon atoms and 90% thiodipropionic acid.
:10 to 10:90 by weight ratio. (2) The magnetic card according to claim 1, wherein a heat-sensitive recording layer is provided on a part or the entire surface of the magnetic recording layer side. (3) The magnetic card according to claim 1, wherein a heat-sensitive recording layer is provided on a part or the entire surface of the opposite side of the magnetic recording layer.