JPH0850719A - Surface material for magnetic card and magnetic card - Google Patents

Abstract

(57) [Abstract] [Purpose] A strong adhesive force without the fear of peeling a paper-like flexible sheet on a telephone card when reading the telephone card, and also causing a read error. Provided is a surface material for a magnetic card, which can be adhered to a telephone card by eliminating warping. [Structure] Compared to the magnetic card body 1, it is a flexible shield with extremely low rigidity.
To the back surface of the gland 21 (for example, Japanese paper, silk cloth, leather), the adhesion temperature is 100 ° C to 150 ° C, and the thickness is 5 μm to 100 μm
The thermoplastic resin adhesive layer 22 was provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface material for a magnetic card used in a telephone card and the like and a magnetic card such as a telephone card.

[0002]

2. Description of the Related Art A magnetic card has a structure in which a magnetic thin film is laminated between sheet-like supports, and in reading, it is taken up by a traveling mechanism such as a roll and passed through a magnetic head. In this magnetic card, especially telephone card, there are people who stick and use single-sided adhesive paper on which names and figures are drawn,
In such a case, the one-sided adhesive paper may be peeled off during traveling during the above-mentioned reading, and the magnetic head of the magnetic card type public telephone may be scratched, resulting in failure.

[0003]

In order to eliminate such problems, it is advantageous to use a thermoplastic resin adhesive having a large cohesive force instead of the above-mentioned pressure-sensitive adhesive.

Therefore, the present inventors have made a solvent-type thermoplastic resin adhesive on one side of Japanese paper, especially a thermoplastic resin adhesive having an adhesive temperature (melting temperature) of 100 ° C. to 150 ° C. at which adhesive strength is large. The agent was applied and dried, and an attempt was made to adhere the agent to the surface side of the telephone card under pressure and heating by a press. However, in the Washi adhesive telephone card obtained in this way, when it is pinched with a finger, it is easily bent and bent, which hinders the use and causes a read error due to the floating of the magnetic head during the read. There is a fear of doing it.

It is presumed that the main cause of such easiness of buckling of the telephone card is the heat shrinkage stress of the thermoplastic resin adhesive layer. That is, as shown in FIG. 3, a sheet 21 'is provided on a telephone card 1'and a thermoplastic resin adhesive layer 2 is provided.
In the case of bonding under pressure and heating by 2 ', a heat shrinkage force (F) due to cooling and solidification is generated in the thermoplastic resin adhesive layer 22', and as a result, the whole tries to bend in the arrow direction. A bending mode (M) acts (from the bending neutral plane nn of the entire system, the thickness center e of the thermoplastic resin adhesive layer 22 ').
If the distance to −e is Δh, then M = F · Δh).

Thus, the bending rigidity of the telephone card 1'is E ₁ I ₁ and the bending rigidity of the sheet 21 'side (composite bending rigidity of the sheet and the thermoplastic resin adhesive layer) is E. ₂ I ₂ , and the bending radius of the warp is r, the bending moment reaction force m ₁ on the telephone card side is r / (E ₁ I ₁ ), and the bending moment reaction force on the sheet side. m ₂ is r / (E ₂ I ₂ ), and M = (m ₁
+ M ₂ ), r = (E ₁ I ₁ + E ₂ I ₂ ) / (F · Δh) holds.

However, if the bending rigidity E ₂ I ₂ on the sheet side is large, the bending radius r can be made sufficiently large even if F is a little large, and the warp caused by F can be eliminated. When the sheet is paper, the flexural rigidity E ₂ I ₂ is a small value that can be substantially ignored. Therefore, when F is large, r becomes so small that the warp cannot be ignored. Thus, a telephone card in which Japanese paper is pasted with a thermoplastic resin adhesive layer has a warp from the beginning, and if the card is held, the warp can be suppressed even if the force is small. Easily buckles in the direction of (
This buckling is called warping)).

An object of the present invention is to attach a flexible sheet such as paper to a telephone card so that the adhesive has an adhesive temperature of 1%.
Even if a thermoplastic resin-based adhesive having a strong adhesive force (strong cohesive force) of 00 ° C to 150 ° C is used, it is necessary to prevent the warping of the telephone card due to the heat shrinkage force of the adhesive layer. .

An object of the present invention is to provide a strong adhesive force without a fear of peeling a soft sheet such as paper on a telephone card when reading the telephone card, and cause a read error. It is an object of the present invention to provide a surface material for a magnetic card, which can be adhered to the telephone card by eliminating warping of the telephone card.

[0010]

A surface material for a magnetic card according to the present invention is provided on the back surface of a soft sheet (for example, Japanese paper, silk cloth, leather) having extremely low rigidity as compared with the magnetic card body. The adhesive temperature is 100 ° C. to 150 ° C., and the thermoplastic resin adhesive layer having a thickness of 5 μm to 100 μm is provided. The magnetic card according to the present invention is characterized in that the magnetic card surface material is adhered to the surface of the magnetic card main body by the thermoplastic resin adhesive layer.

FIG. 1 shows a magnetic card according to the present invention.
Is a magnetic card body. In FIG. 1, reference numeral 2 denotes a surface material for a magnetic card according to the present invention, which has a bonding temperature of 1 on the back surface of a flexible sheet 21 having extremely low rigidity as compared with the magnetic card body 1.
A thermoplastic resin adhesive layer 22 having a thickness of 5 μm to 100 μm and a temperature of 00 ° C. to 150 ° C. is provided.

In the magnetic card main body 1, a magnetic thin film, for example, γ solidified with a binder, is provided between sheet-like supporting base materials, for example, engineering plastic sheets such as polyacetal.
A stack of hematite thin films can be used. For the flexible sheet 21 having extremely low rigidity, Japanese paper which enables writing, or silk cloth or leather which softens the touch can be used.

The thermoplastic resin adhesive 22 includes styrene-isoprene-styrene block copolymer, styrene-butadiene-styrene block copolymer, polyvinyl acetate, ethylene-vinyl acetate copolymer, polyamide,
Phenoxy resin, ethyl cellulose, polyisobutylene, polyester and the like can be used alone or in a solvent solution of two or more kinds. For the production of the surface material for magnetic cards, a method of applying and drying the solvent solution of the thermoplastic resin on the back surface of the flexible sheet can be used.

In the present invention, the reason why the thermoplastic resin adhesive having an adhesive temperature of 100 ° C. to 150 ° C. is used is that the adhesive force is too low at 100 ° C. or less and the adhesive strength is sufficient (3 kg / (10 mm or more) is difficult to guarantee, and there is a fear that the magnetic thin film of the magnetic card body may be adversely affected at 150 ° C. or more. In the present invention, the reason why the thickness of the thermoplastic resin-based adhesive layer is limited to 5 μm to 100 μm is that if the thickness is 5 μm or less, it is difficult to evenly apply the adhesive due to coating breakage, and if the thickness is 100 μm or more, the adhesive is adhered. This is because the heat shrinkage force (F) accompanying the cooling and solidification of the thermoplastic resin adhesive layer at that time becomes too large, and the magnetic card is warped.

The magnetic card according to the present invention comprises a thermoplastic resin-based surface material according to the present invention on the surface of the magnetic card body (the surface opposite to the surface contacting the magnetic head during reading). It is made by stacking the adhesive surfaces and pressing and heating them with a press.If the soft sheet of the surface material is paper,
The paper can be preprinted.

In the magnetic card and the surface material for a magnetic card according to the present invention, depending on the viscosity of the thermoplastic resin adhesive at the time of heating and melting and the density of the Japanese paper, FIG.
In the same manner as described above, 1 indicates a magnetic card body, 21 indicates a soft sheet such as Japanese paper, silk cloth, and leather, and 22 indicates a thermoplastic resin adhesive layer. The barrier layer 23 is provided to prevent the molten adhesive from seeping out to the surface of the Japanese paper (preventing stains on the printing) when the thermoplastic resin adhesive layer 22 is heated and melted, and to prevent ink or ink from bleeding and bleeding. Can be prevented.

The thickness of the surface material 2 according to the present invention is 150 μm so as not to hinder the running of the magnetic card during reading.
Therefore, the thickness of the flexible sheet 21 or the total thickness of the flexible sheet 21 and the barrier layer 23 is set to satisfy this condition.

[0018]

[Function] The thermoplastic resin adhesive layer of the surface material is adhered to the main body of the magnetic card under heat and pressure, and the thermal shrinkage of the thermoplastic resin adhesive layer during cooling is caused by the thermoplastic resin adhesive layer. When the magnetic card body is coupled to the magnetic card body, the magnetic card body is blocked due to its high rigidity, so that a heat shrinkage force is generated. The heat shrinkage force F is proportional to the heating temperature ΔT and the thickness of the thermoplastic resin adhesive layer.

In FIG. 1, the flexural rigidity (E ₁ I ₁ ) of the magnetic card body 1 is greater than the flexural rigidity (E ₁ I ₁ ) of the flexible sheet 21.
₂ I ₂₎ is very low, because it is _{E 1 I 1 »E 2 I 2} , In the above formula, ignoring E ₂ I _2, magnetic card based on the heat shrinkage force F - bending of the warp of the de The radius r is given by r = (E ₁ I ₁ ) / (F · Δh).

However, in the present invention, since the thickness of the thermoplastic resin adhesive layer is 100 μm or less, F
Can be made sufficiently small and r can be made large. Therefore, even if the warp occurs, the radius of curvature of the warp can be made sufficiently small, and the warp (warpage) from the initial stage can be limited to a small value that is substantially problem-free.

Also in the case shown in FIG. 2, the flexural rigidity (E ₂ I ₂ ) of the flexible sheet 21 and the barrier layer 23 is extremely higher than that of the magnetic card body 1 (E ₁ I ₁ ). Due to the lowness, the same effect as above is achieved.

[0022]

【Example】

Example A thermoplastic resin (melting point 120 ° C.) styrene-butadiene-styrene block copolymer concentration 50% solvent solution (toluene is used as a solvent) is applied to the back surface of a 120 μm thick silk fabric and dried. A surface material having a thermoplastic resin adhesive layer having a thickness of 50 μm was prepared. The thermoplastic resin adhesive layer of this surface material is applied to the NTT telephone card (8
5 x 58 mm), and the interface is pressed at a pressure of about 1 to
The surface material-attached telephone card was prepared by adhering at a temperature of about 120 ° C. for 3 minutes at a pressure of 3 kg / cm ² .

[Comparative Example 1] The same as Example, except that the thickness of the thermoplastic resin adhesive layer was 3 μm.

[Comparative Example 2] An organic solvent type synthetic rubber adhesive having an adhesion temperature of 70 ° C. was used as the thermoplastic resin adhesive, and the heating temperature at the time of adhesion was about 70 ° C. Same as

With respect to these Example products and Comparative Example products (the number of each sample is 20), the easiness of warpage was inspected (the both ends in the length direction were pinched with fingers and the difficulty of buckling was inspected). In the example and the comparative example 2, no difference was observed from the NTT telephone card on which the silk fabric was not adhered, but in the comparative example 1, it was easier than the NTT telephone card and the silk fabric adhesive surface side was all concave. It was bent in the direction, and the directionality of the bending was recognized (Example, NTT telephone card and Comparative Example 1).
Then, this direction was not recognized).

When the adhesive strength of the silk fabric was measured,
In the example and the comparative example 1, all samples were 3 kg / 10 m.
However, in the comparative example, none of them reached 3 kg / 10 mm. Therefore, in the example,
It satisfies both requirements of no warpage of telephone card with surface material attached and strong adhesion of silk fabric.

[0027]

According to the present invention, even if a telephone card is used with a paper or the like attached, the adhesion strength can be made sufficiently strong. Therefore, the card by peeling the paper or the like can be used. It is possible to avoid a telephone failure caused by clogging and to eliminate the curling of the card, so that the read error caused by the curving can be avoided. Therefore, according to the present invention, the use of the telephone card can be diversified by modifying the surface of the telephone card.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of a magnetic card according to the present invention.

FIG. 2 is an explanatory view showing another embodiment of the magnetic card according to the present invention.

FIG. 3 is an explanatory diagram for showing a warp of a sheet-attached magnetic card.

[Explanation of symbols]

 1 Magnetic Card Main Body 2 Surface Material for Magnetic Card 21 Flexible Sheet 22 Thermoplastic Resin Adhesive Layer 23 Barrier Layer

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C09J 7/02 JJT JLE 7/04 JHV

Claims (4)

[Claims] 1. A thermoplastic resin adhesive layer having an adhesion temperature of 100 ° C. to 150 ° C. and a thickness of 5 μm to 100 μm is provided on the back surface of a flexible sheet having extremely low rigidity as compared with the magnetic card body. A surface material for a magnetic card, which is characterized in that 2. The surface material for a magnetic card according to claim 1, wherein the soft sheet is any one of paper, silk cloth and leather. 3. The surface material for a magnetic card according to claim 1, wherein a barrier layer is provided between the soft sheet and the thermoplastic resin adhesive layer. 4. A magnetic card characterized in that the surface material for a magnetic card according to any one of claims 1 to 3 is adhered to the surface of a magnetic card main body by a thermoplastic resin adhesive layer thereof.
De.