JPH01209193A - Thermal color forming card - Google Patents

Abstract

PURPOSE:To eliminate nonuniformity in printing by a thermal head, enhance resolution and prevent difficulty with which overlapped cards are separated due to excessively high adhesion, by a method wherein the surface roughness of a thermal color forming card on the thermal color forming layer side in contact with the thermal head is set to a specified Bekk smoothness. CONSTITUTION:The surface roughness of a thermal color forming part in contact with a thermal head is set to a Bekk smoothness of 30-300sec, in a thermal color forming card comprising the thermal color forming part on a base. With the surface smoothness set to a Bekk smoothness of at least 30sec, printing with favorable resolution can be achieved. This is because the smoothened surface of the color forming layer ensures higher adhesion to the thermal head, higher uniformity in transfer of heat from the head to the color forming layer, and printing with favorable resolution and uniformity. If the smoothness is enhanced excessively, it is difficult to take out one card from a stack of the cards, due to excessively high adhesion between the cards. Therefore, the smoothness of the color forming layer is limited, the upper limit being a Bekk smoothness of 300sec.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a heat-sensitive coloring card, and more particularly to improving the printing accuracy of the heat-sensitive coloring layer thereof.

[Conventional technology]

2. Description of the Related Art In recent years, the use of so-called prepaid cards, such as telephone cards, in which a prepaid card is purchased and the card is used to receive services within the range of the fee has become popular.

When using this card, the method of displaying the card's balance is to punch a hole in the balance number part of the amount column,
Alternatively, a method such as printing a mark is used.

The method using perforation has problems such as the disposal of plastic debris generated by the perforation, and as an alternative to this method, a method using printing has been developed.

As a printing method, there is a method in which a heat-sensitive coloring area is provided on the card and printing is performed on that area using a heat generating head for printing. In this case, the surface of the card is rough, so the heat from the heat-generating head used to draw letters and pictures is not transferred uniformly, resulting in uneven printing, so the disadvantage is that it can only be used for making marks at best. there were.

[Problem that the invention seeks to solve]

The present invention solves the disadvantage that thermal coloring cards using the above-mentioned thermal printing method, especially so-called magnetic cards equipped with a magnetic recording part, are prone to print unevenness, thereby making it possible to print characters and pictures with high resolution. To provide a heat-sensitive coloring card that does not cause the cards to adhere to each other and become difficult to peel off when two or more cards are stacked one on top of the other.

[Means to solve the problem]

In order to solve the above problems, as a result of various research,
The present inventors have discovered that printing with good resolution can be obtained by setting the surface roughness of the surface of the thermosensitive coloring layer that comes into contact with the heating head to a degree of smoothness of 30 seconds or more, thereby completing the present invention. This is because the surface of the coloring layer becomes smooth, which improves the adhesion with the heat generating head, and the heat transfer from the heating head to the coloring layer becomes uniform, resulting in uniform and high resolution printing. I believe.

On the other hand, if the smoothness is improved too much, when stacking cards and trying to take them out one by one, the stacked cards will stick together and become difficult to remove.

For this reason, there is a limit to the smoothness of the coloring layer, and the Bekk smoothness is preferably 300 seconds or less.

In order to improve the smoothness of the heat-sensitive coloring layer, a heat-sensitive coloring paint was applied to the substrate, dried, a protective film was provided on the surface, and this was achieved by calendering at a temperature of about 40°C.

The temperature of calendering needs to be below the temperature at which the thermosensitive coloring layer develops color. Therefore, the temperature at which the effect of calendering is recognized and color development is suppressed is desirable, and the temperature is 40 to 55%.
The range of 0°C is the range in which good results can be obtained.

Furthermore, since the thermosensitive coloring agent also has pressure-sensitive coloring properties, the pressure in calendering etc. cannot be increased too much. However, by providing a protective layer on the surface of the coloring layer, the pressure sensitivity can be weakened, so by providing the protective layer on the surface of the coloring layer and then performing calendering, surface smoothness can be improved.

The material used for the protective layer has adhesive properties with the base layer.
Any resin with a transparent coating can be used.

〔Example〕

Hereinafter, the present invention will be explained in detail based on Examples.

As the heat-sensitive coloring layer paint, the following paint was used: 10 parts by weight of coloring agent (manufactured by Showa Denko: Papilol SD-120) color developer
25 parts by weight/O (manufactured by Showa Denko K.K.: Papilol CD-214) Polymethyl methacrylate 15 parts by weight (PMMA) Toluene 200 parts by weight or more of the composition was dispersed in a sand mill to obtain a paint for a heat-sensitive coloring layer.

Example 1 A magnetic layer with a coercive force of 15,000e was formed on a polyethylene terephthalate film with a thickness of 200 μm to a thickness of 5 μm after drying.
On the opposite side, the coating material for the heat-sensitive coloring layer was coated and dried to a thickness of 4 μm after drying to obtain a heat-sensitive coloring layer. PMM on this thermosensitive coloring layer
After applying A to a thickness of 3 μm, calendaring was performed using a roll at a temperature of 40°C.

The surface smoothness of the obtained thermosensitive coloring layer was 15 in Bekk smoothness.
It was 0 seconds.

Example 2 The heat-sensitive coloring magnetic card obtained in Example 1 was further brought into close contact with a glass plate on the heat-sensitive coloring layer side, a load of 1000 f was applied, and the card was left at a temperature of 60°C for 24 hours.

The Bekk smoothness of the heat-sensitive coloring layer side of the obtained card was 250.
It was seconds.

Comparative Example 1 A card that was not calendered in Example 1, and the Beck smoothness on the heat-sensitive coloring layer side was 15 seconds.

Comparative Example 2 The heat-sensitive coloring layer side of the card obtained in Example 1 was brought into close contact with a glass plate, a load of 200 (H') was applied, and a temperature of 60
It was left at °C for 48 hours. The Bekk smoothness of the heat-sensitive coloring layer side of the obtained card was 470 seconds.

8d□j/m was added to the cards obtained in the above Examples and Comparative Examples.
With an applied energy of 30 mj/- with a heating head of +
Print a dot-width line, observe the print with a microscope,
The presence or absence of breaks in the lines was investigated.

In addition, solid printing was performed on the entire surface of the coloring layer, and the appearance of density unevenness was observed using a full microscope.

Furthermore, when two cards were stacked one on top of the other and a load of 10 y was applied to the upper card, it was examined whether the lower card would be pulled horizontally.

The results are shown in the table below.

〔Effect of the invention〕

As explained above, the surface roughness of the surface of the heat-sensitive color-forming layer side of the heat-sensitive color-forming card that comes into contact with the heat-generating head is determined by Beck smoothness of 3.
By setting the time to 0 seconds or more and 300 seconds or less, the printing by the heating head becomes even and the resolution is improved.
Moreover, it is possible to produce a heat-sensitive coloring card that solves the problem that when stacked, they stick together and become difficult to remove.

Patent applicant: Hitachi Maxell, Ltd. Representative Atsushi Nagai

Claims (2)

[Claims] (1) A heat-sensitive coloring card having a heat-sensitive coloring portion on the base material, characterized in that the surface of the heat-sensitive coloring portion that comes into contact with the heat-generating head has a surface roughness of 30 seconds to 300 seconds in Bekk smoothness. Colored card. (2) The heat-sensitive coloring card according to claim (1), wherein the base material further includes a magnetic recording portion.