JPS6057128B2 - Transferable magnetic sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a transferable magnetic sheet that is colored in a colorful manner to hide the brown color of the magnetic layer.

This type of transferable magnetic sheet has a basic structure in which a colored layer, a masking layer, and a magnetic layer are sequentially formed on a base film. After the magnetic layer and colored layer are transferred to an adherend under pressure and heat, the base film is It is now possible to peel it off to create magnetic recording cards.

However, in order to completely hide the deep brown color of the magnetic layer and freely produce a clear color, a masking layer is essential, and moreover, the thickness of the masking layer and the colored layer must be considerably increased. Therefore, when the magnetic recording card is used, there is a problem that the gap loss between the magnetic head and the magnetic layer becomes too large and the magnetic output is attenuated. Therefore, attempts have been made to form the masking layer using a metal vapor deposition film (for example, Japanese Utility Model Application No. 53-41911).

As shown in FIG. 4, its structure has an adhesive layer 6 on the back side of a base film 1, and a magnetic layer 4, a metal vapor deposited film layer 3, and a colored layer 2 are sequentially formed on the front surface. .
According to this, the background color of the magnetic layer 4 can be sufficiently hidden by setting the thickness of the metal vapor deposited film layer 3 to 0.5 μm or less. Accordingly, the thickness of the colored layer 2 can be made as thin as possible. However, in reality, when each layer is laminated on the base film 1 in the order of the magnetic layer 4, the metal vapor deposited film layer 3, and the colored layer 2, the adhesion between the metal vapor deposited film layer 3 and the colored layer 2 is poor. There is a drawback that the colored layer 2 is easily peeled off.

The reason for this is not clearly understood, but in addition to magnetic powder, the magnetic layer 4 contains a large amount of various other substances, and among these, substances such as lubricants may cause metal aluminum to coat the magnetic layer 4. It is thought that this is because when vacuum evaporation is performed on the metal evaporation film layer 3, the metal evaporation layer 3 seeps out onto the surface of the metal evaporation film layer 3, and the surface of the metal evaporation film layer 3 becomes in a state as if it had been subjected to a female mold treatment. Further, the surface of the magnetic layer 4 is inevitably rough.

Therefore, since the metal vapor deposition film layer 3 is also extremely thin, its surface is finished with an uneven surface, and its own color does not appear as it is. In other words, there was room for improvement in that the colored layer 2 had to be made thicker depending on the color tone because whiteness did not appear and the masking effect was not sufficient. Focusing on this fact, the present inventor has determined that the masking layer should be made of metal in transferable magnetic sheets in which the stacking order of the magnetic layer, metal vapor deposited film layer, and colored layer is reversed from that of the adhesive magnetic sheet. The effect of forming a vapor-deposited film layer can be fully demonstrated.

This is how I came up with this invention.
That is, the present invention provides a transferable magnetic sheet having a structure in which a colored layer, a metal vapor deposited film layer, and a magnetic layer are laminated in this order on a base film, thereby improving the adhesion between these three layers. is the primary purpose.

A second purpose is to completely mask the ground color of the magnetic layer with the metal vapor deposited film layer so that the colored layer can freely produce a clear color. Furthermore, when a magnetic recording card or the like is created by making the thickness of the colored layer and metal vapor deposition layer as thin as possible, the gap loss between the magnetic layer and the magnetic head is reduced, and the magnetic output is attenuated. The third purpose is to reliably prevent this. What is particularly noteworthy about this invention is that the surface of the base film is a smooth surface, and therefore the surface of the colored layer formed on this smooth surface is also thinner than the magnetic layer, and the amount of various pigments mixed is also small. Since it is relatively small, the surface is finished smooth. As a result, the metal vapor-deposited film layer formed on the smooth surface of the colored layer perfectly performs the masking function even if the film thickness is reduced. This also creates a mutually synergistic effect in that the colored layer can be made thinner. As the metal vapor deposition layer, aluminum,
It is formed by a known vacuum evaporation method using zinc, tin, lead, copper, silver, etc. The film thickness was 0.5 μm or less, which was sufficient. In addition, aluminum oxide, zinc oxide, titanium oxide,
A vapor deposited film layer made of a metal oxide such as lead oxide, tin oxide, copper oxide, silver oxide, etc. may also be provided. Next, embodiments of the present invention will be described based on the drawings. EXAMPLE A colored paint having the following composition is applied onto a polyester film 1 having a thickness of about 50 μm to form a colored layer 2 having a thickness of 3 μm.

Next, aluminum is coated on this colored layer 2. A vacuum-deposited film layer 3 is formed to a thickness of 0.3 μm by vacuum evaporation, and a magnetic paint having the composition shown below is applied thereon to a thickness of approximately 13 μm after drying.
A magnetic layer 4 having a thickness of m is formed to obtain the transferable magnetic sheet shown in FIG. The transferable magnetic sheet obtained in this way is made of PVC! The base film 1 is overlaid on the adherend 5 of
Temperature 120C1 Pressure 100K9/
The magnetic layer 3 and the colored layer 2 were transferred to the adherend 5 in this order by applying pressure and heating for O'' seconds under the condition of Cll to produce the magnetic recording card shown in FIGS. 2 and 3. . O Coating composition of colored layer O Coating composition of magnetic layer IV--'
υυ ″ノ] [1=ノ18
;! Example 5 A magnetic layer 4 with a dry thickness of about 13 μm was formed using the magnetic paint used in the example on the surface of a polyester base film 1 with a thickness of 0 μm, and then an aluminum vapor-deposited film layer 3 of 0.3 μm was applied.
A colored layer 2 is formed on the base film 2 to a thickness of 3 μm, and a pressure-heat sensitive adhesive layer 6 is formed to a thickness of about 30 pm on the back surface of the base film 1, as shown in FIG. An adhesive magnetic sheet shown in the figure was prepared, and this was heated under pressure on a vinyl chloride adherend 5 via the adhesive layer 6 to produce a magnetic recording card.

A comparative experiment was conducted to examine the adhesion between the colored layer 2 and the metal vapor deposited film layer 3 of each magnetic sheet obtained in the example and the comparative example.

The experimental results are shown in the table below. However, the experimental method was to put colored layer 2 on top and apply 1.5w! The area where the colored layer 2 is peeled off from the metal vapor deposited film layer 3 when cuts are made in a grid pattern at intervals of t and a commercially available adhesive tape (for example, Dumplon manufactured by Nitto Denko Corporation) is pasted thereon and then peeled off. was expressed as a percentage. As is clear from this table, in the transferable magnetic sheet according to the example of the present invention, the adhesion of the colored layer 2 to the metal vapor deposited film layer 3 is significantly improved compared to the adhesive magnetic sheet according to the comparative example. It was confirmed that this method is meaningful in improving the conventional drawbacks.

Of course, the magnetic layer 4 is formed by forming the metal vapor deposited film layer 3.
The transferable magnetic sheet according to the present invention has the colored layer 2, the metal vapor deposited film layer 3, and the magnetic layer 4 arranged in the order listed, since the adhesiveness between the two is originally good. Because it is formed by coating, it can be tightly connected as one body.
Especially when creating a magnetic recording card, the colored layer 2 on the surface
It has now been possible to reliably prevent the peeling off. In addition, since the order of coating and forming each layer is opposite to that of the conventional comparative example,
The thickness of each of the colored layer 2 and the metal vapor deposited film layer 3 can be made as thin as possible, and the color tone of the colored layer can be freely selected and brought out vividly.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of a transferable magnetic sheet according to the present invention, FIG. 2 is a plan view of a magnetic recording card produced by transferring this transferable magnetic sheet, and FIG. 3 is an A of FIG. 4 is a longitudinal cross-sectional view of a conventional adhesive magnetic sheet (comparative example). DESCRIPTION OF SYMBOLS 1...Base film, 2...Colored layer, 3...Nonmagnetic metal vapor deposited film layer, 4...Magnetic layer, 5... Adherent.

Claims (1)

[Claims] 1. A transferable magnetic sheet comprising a base film 1, a colored layer 2, a non-magnetic metal vapor deposited film layer 3, and a magnetic layer 4 formed in this order.