JPH02239427A - Magnetic card - Google Patents

Abstract

PURPOSE:To obtain a clear visual display by incorporating a microcapsule layer and a flake-type metal powder into the visual display area, the metal powder changes its orientation according to the magnetic field generated by the magnetic card itself and consequently changes the reflectivity against incident visual light. CONSTITUTION:The microcapsule layer 30 is formed on one surface of the magnetic card 20 to form the visual display area. The microcapsule layer 30 contains a binder 31 and plural number of microcapsules 32 dispersed in the binder, and the microcapsule 32 contains oil 33 properly selected and the flake- type metal powder 34. The metal powder changes its orientation according to the magnetic field generated by the magnetic card itself and changes the reflectivity against the incident light. Thus, the reflectivity against the incident light can be sufficiently changed so that more clear display can be obtained.

Description

Detailed Description of the Invention (11) Object of the Invention [Industrial Application Field 1] The present invention relates to a magnetic card, and in particular to a magnetic card formed by dispersing a plurality of microcapsules containing plate-shaped metal powder in a binder. This invention relates to a magnetic card in which a visible display area is formed by arranging a microcapsule layer on the surface of a magnetic card body.
1-250832, a magnetic fluid layer of an appropriate shape is disposed on the substrate of the magnetic card body or the magnetic recording layer, so that the magnetic fluid layer changes as the magnetic recording layer is magnetized. By changing the orientation direction of the ferromagnetic fine particles contained in the magnetic fluid in the microcapsules dispersed in the magnetic fluid layer, the optical reflectance of the magnetic fluid layer for visible incident light is changed, and the content recorded on the magnetic recording layer is changed. A proposal was made to make it more visible. [Problems to be solved] However, with conventional m-ki cards, fit IT!
The particle size of the ferromagnetic particles contained in the magnetic fluid is about 100 mm, which is extremely small compared to the wavelength of visible light (about 5000 mm), and the smallest particle size of the ferromagnetic particles contained in the magnetic fluid. Since the ratio between the cross-sectional area and the maximum cross-sectional area was small, there was a drawback that the light reflectance for visible incident light could not be substantially changed even if the orientation direction was changed;
Since it was a magnetic fluid, the particle size of the ferromagnetic particles was set to 120.
It had the disadvantage that it could not be expanded beyond the human level, and there was virtually no room for improvement. In order to eliminate these drawbacks, the present invention has developed a method in which a microcapsule layer formed by dispersing a plurality of microcapsules containing sheet metal powder together with oil in a binder is placed on the surface of a magnetic card body. The purpose is to provide a magnetic card with a visible display area formed by this method. {2} Configuration of the Invention Means for Solving Problem E] The means for solving the problem provided by the present invention is as follows. (b) a microcapsule layer formed by fractionating a plurality of microcapsules in a binder placed against the surface; 1. A magnetic card characterized in that a visible display region includes plate-shaped metal powder whose orientation direction is changed according to the direction of a generated magnetic field and whose light reflectance to visible incident light is changed. [Function] The magnetic card according to the present invention is a magnetic card in which a visible display area is arranged on the magnetic card body, and the visible display area is fa) a binder arranged on the surface of the magnetic card body. a microcapsule layer formed by dispersing a plurality of microcapsules therein;
b) A plate-shaped plate that is accommodated together with oil in each microcapsule of the microcapsule layer, and whose orientation direction is changed according to the direction of the magnetic field generated by the magnetic card body, thereby changing the light reflectance for visible incident light. (if) When the orientation direction of the plate-shaped metal powder is changed, the light reflectance for visible incident light is sufficiently changed, and (if) It works to clarify the visual display. [Example] Next, the magnetic card according to the present invention will be described in detail by giving preferred examples thereof. However, the examples described below are described to facilitate or promote understanding of the present invention, and are not described to limit the present invention. In other words, each element disclosed in the embodiments described below includes all design changes and equivalent substitutions that fall within the spirit and technical scope of the present invention. FIG. 1 is a partial cross-sectional perspective view showing an embodiment of the magnetic card according to the present invention, and shows a microcapsule layer 3 for forming a visible display area on one side of the magnetic card body.
0 is placed. FIG. 2 (al and lbl are both partially enlarged cross-sectional views of the embodiment in FIG. 1. 3 shows the relationship with the distribution direction of the powder 34. FIG. 3 fal is a flowchart showing the manufacturing procedure of the embodiment in FIG. It shows how metal powder 34 is contained together with oil (dodecylbenzene in this case) 33 and applied onto the magnetic card body U. Fig. 3(b) shows a part of the manufacturing procedure of the embodiment shown in Fig. 1. It is a flowchart diagram showing the procedure for processing the plate-shaped metal powder 34 accommodated in the microcapsules 32, and particularly the case where the plate-shaped metal powder 34 is coated with a surfactant (not shown). First, Figure 1 and Figure 2 (a)
The configuration of an embodiment of the magnetic card according to the present invention will be described in detail with reference to the fbl.

The plate is a magnetic card according to the present invention, and a microcapsule layer 30 is disposed on one surface of the magnetic card body to form a visible display area. The magnetic card body is made in a well-known manner and includes a magnetic recording area located near the microcapsule layer. The microcapsule layer includes a plurality of microcapsules 32 dispersed in a binder 31 and an appropriate oil (for example, dodecylbenzene, etc.) 3 in each microcapsule 32.
3 and a plate-shaped metal powder 34 housed therein. As the plate-shaped metal powder 34, five-plate magnetic metal powder (for example, plate-shaped powder of iron oxide or iron-cobalt alloy) is suitable. The size of the plate metal powder 34 is preferably about 1 μm or more in order to reflect visible incident light, and is determined as appropriate depending on the size of the microcapsules 32, for example. size is 1
When the size is about 00 μm, it is preferable that the size is about 5 to 15 μm. If an appropriate surfactant (for example, sodium oleate or succinimide) that does not easily react with the plate metal powder 34 and the oil 33 is placed around the plate metal powder 34, (i) the plate It is possible to suppress the mutual agglomeration of the shaped metal powders 34 and fi
It is possible to prevent the iltJj-like metal powder 34 from adhering to the wall surface of the microcapsule 32, and in turn (ifi) increase the capacity of the plate-shaped metal powder 34 in the microcapsule 32. Plate metal rIX that can stably contain the powder 34 and resist visible incident light.
It is preferable because the light reflectance of the powder 34 can be improved. Furthermore, with reference to FIGS. 1 to 3 (at (bl), the manufacturing procedure for an embodiment of the magnetic card according to the present invention will be explained in detail. (Preparation of layer I card 10) Plate metal Powder (for example, iron oxide plate-shaped powder with a size of 5 to 15 μm) 34 is placed in an ultrasonic cleaner together with oil (here, dodecylbenzene is exemplified) 33, and the dodecyl as oil 33 is removed by ultrasonic vibration. The plate metal powder 34 is dispersed in benzene (the resultant product is referred to as a "plate metal powder dispersion"). On the other hand, by mixing water, an aqueous gelatin solution, an aqueous gum arabic solution, etc. in an appropriate ratio and thoroughly stirring the mixture, a gelatin rubber mixture solution that becomes the binder 31 in the microcapsule layer concave is prepared. The gelatin rubber aqueous solution is made of, for example, 140 cc of water, 30 g of a 1 liter weight % gelatin aqueous solution (pig skin gelatin aqueous solution with an isoelectric point p of 14.5), and 11
30 g of aqueous gum arabic solution and 2% aqueous ethylene-maleic anhydride copolymer solution (molecular weight 80,000; p
}16) and a small amount of Span 80 mold as an activator are mixed together and stirred thoroughly. This case will be exemplified below, but the present invention is not limited thereto, and any material may be used in any proportion as long as the microcapsule layer depressions can be formed. After the gelatin rubber mixture has been stirred appropriately, it is heated to an appropriate temperature in order to facilitate the dispersion of the plate metal powder fraction. The plate metal powder dispersion and the gelatin rubber mixture are mixed and stirred to form an intermediate dispersion in which fine particles of the plate metal powder dispersion are dispersed in the gelatin rubber mixture. Thereafter, acetic acid (for example, 10% by weight) is added dropwise to the intermediate dispersion while stirring until the pH becomes 4 to 4.5.
As a result, a film of gelatin and gum arabic is formed around the fine particles of the plate metal powder dispersion (substantially dodecylbenzene). The intermediate dispersion into which acetic acid has been added dropwise is allowed to cool while stirring to coagulate the membrane of gelatin and gum arabic placed around the fine particles of the plate metal powder dispersion (substantially dodecylbenzene). ．． An appropriate amount of 5-glutaraldehyde aqueous solution (e.g. 25% by weight) is added to the cooled intermediate dispersion, and gelatin and Arabica are added to the cooled intermediate dispersion, and gelatin and arabic are added around the fine particles of the plate metal powder dispersion (substantially dodecylbenzene). This further solidifies the rubber film. As a result, microcapsules are dispersed in gelatin and gum arabic. The microcapsules contain a dispersion of plate metal powder (and thus the plate metal powder and dodecylbenzene) (herein referred to as the "microcapsule liquid"). Next, a sodium hydroxide aqueous solution (for example, 20% by weight) is added to the microcapsule liquid while stirring.
It is dripped until . After dropping the aqueous sodium hydroxide solution, the microcapsule liquid is continued to be stirred for an additional 3 to 5 hours. After the stirring is completed, the microcapsule liquid is applied onto the surface of the separately prepared magnetic card body 20 to an appropriate thickness (for example, 400 to 500 μm), and is dried and solidified to form the microcapsule layer 30. It is said that Through the above steps, the 6n-ki card publication according to the present invention is created. A surfactant (for example, sodium oleate or succinimide) is applied around the plate-shaped metal powder 34 described above in accordance with the procedure shown in FIG. 3 and detailed below. This can suppress the plate-shaped metal powder 34 from coagulating with each other when taken into the microcapsule 32 together with the oil 33, and also allows the plate-shaped metal powder 34 to adhere to the wall surface of the microcapsule 32. This can prevent the microcapsules 32 from being exposed to
The capacity of the plate-shaped metal powder 34 to be accommodated can be increased, and as a result, the light reflectance to visible incident light can be improved, so that the visual display of the magnetic card (1) according to the present invention can be made clear or stabilized, and is therefore preferred. The plate metal powder 34 of Step 34 is mixed with an aqueous solution of sodium oleate (for example, 5% by weight) as a surfactant and stirred. The plate metal powder 34 is added in an appropriate proportion to the sodium oleate aqueous solution (the sodium oleate aqueous solution is 5% by weight).
(at a ratio of about 20 to 30% by weight) (in other words,
It is preferable to mix the sodium oleate in an amount sufficient to coat the periphery of the plate-shaped metal powder 34. Mixed solution of plate metal powder 34 and sodium oleate aqueous solution (hereinafter referred to as "plate metal powder mixed solution")
The plate-shaped metal powder 34 is dispersed in the sodium oleate aqueous solution by thorough stirring, and then heated.
As a result, at least more sodium oleate is adsorbed around the treated metal powder 34. After heating and adsorption, the plate-shaped metal powder mixture is allowed to cool to an appropriate temperature, and the sodium oleate is stably arranged around the plate-shaped metal powder 34. The plate metal powder mixture is
After being allowed to cool sufficiently, hydrochloric acid (for example, 1 normal) is added dropwise until the pH becomes 6. As a result, the plate metal powder 34
The excess sodium oleate placed around the is removed. Thereafter, the plate metal powder mixture is washed with water to remove excess sodium oleate from around the plate metal powder 34, which was removed by hydrochloric acid. After washing, the mixed solution of plate metal powder is filtered while applying negative pressure to remove excess moisture, and is finally dried and zested. As described above, the periphery of the plate-shaped metal powder 34 is coated with an appropriate surfactant (here, "sodium oleate"). In addition, the operation of an embodiment of the magnetic card according to the present invention will be explained in detail with reference to FIG. 1 and FIG. 2(a) (bl). A magnetization device (not shown) causes the magnetic recording region of the magnetic card body, which is located near the microcapsule layer and is magnetized in a direction perpendicular to the surface (see Figure 2), to the surface. The plate metal powder 34 in the microcapsules 32, which was initially oriented in the direction perpendicular to the surface, becomes parallel to the surface of the g1 card body. As a result, the visible light incident from the outside is sufficiently reflected, and the reflected light can be clearly seen from the outside.In contrast, the magnetic card body U's magnetic When the direction of the magnetic field in the recording area is changed from the direction parallel to the surface of the recording area (see Figure 2(b)) to the original perpendicular direction (see Figure 2(a)), the magnetic field in the microcapsule layer is The plate metal powder 34 housed in the microcapsules 32 is arranged in a direction perpendicular to the surface of the magnetic card body.Therefore, when visible light is incident, the plate metal powder 34 absorbs the visible light. According to the magnetic card main body of the present invention, as described above, according to the magnetic card main body of the present invention,
The orientation direction of the plate-shaped metal powder 34 accommodated in the microcapsules 32 in the concave microcapsule layer can be changed according to the direction of the magnetic field applied to the magnetic card body located near the visible display area. The recorded contents recorded in the magnetic recording area of the main body can be clearly seen. (3) Effects of the Invention As is clear from the above description, the magnetic card according to the present invention is a magnetic card in which a visible display area is arranged on the magnetic card body, in which: (a) the visible display area is arranged on the surface of the magnetic card body; A microcapsule layer is formed by dispersing a plurality of microcapsules in a binder. The visible display area includes a plate-shaped metal powder whose orientation direction is changed accordingly to change the light reflectance with respect to visible incident light; (i) plate-shaped metal powder; When the orientation direction of the oil is changed, the light reflectance for visible incident light is sufficiently changed, and the effect that can be seen even further is 33... Oil 34...・・・・・・Plate metal powder (i i) Has the effect of making visual display clearer.

[Brief explanation of drawings]

Claims (1)

[Claims] In a magnetic card in which a visible display area is arranged on the magnetic card body, (a) a plurality of binders (31) arranged on the surface of the magnetic card body (¥20); A microcapsule layer (¥30) formed by dispersing microcapsules (32); The plate metal powder (34) whose orientation direction is changed according to the direction of the magnetic field generated by the magnetic card body (¥20) and whose light reflectance to visible incident light is changed is visually displayed. A magnetic card characterized by containing areas.