JPH0453798A - Method for visual recording on card - Google Patents

Abstract

PURPOSE:To eliminate the remaining of printing at the time of erasure when recording is applied to a frost surface by a thermal head by forming the same unevenness as the unevenness formed by the heating due to a thermal head to a smooth surface at temp. higher than the heating temp. due to the thermal head prior to applying frost treatment to the smooth surface within the temp. range from the glass transition temp. of a resin to the m.p. thereof. CONSTITUTION:In a card 1, a smooth surface 11 composed of a synthetic resin and a support layer 12 composed of a polyethylene terephthalate sheet or paper having high strength are laminated and a part of the smooth layer l is set to a recording part 13 and printing 14 is applied to the surface other than the recording part 13 of the smooth surface 11 to display necessary explanation or a decorative design. The unevenness 21 same to the unevenness formed by a thermal head is formed on the smooth recording part 13 of the card 1 at temp. T3 higher than the temp. T2 at the time of the formation of an image. This temp. T3 is pref. set to the m.p. of the resin or lower in order to prevent sticking.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application l'F) The present invention is a method for repeatedly forming clearly visible recorded images on cards that are used repeatedly, such as commuter passes, admission passes, and various prepaid cards. Regarding how to erase.

(Prior Art) Commuter passes for public transportation, permits for entering event venues and buildings, etc. are used repeatedly every day, but due to management reasons, there is no way to check for unauthorized boarding or unauthorized entry.

In recent years, a magnetic card-based check method has been adopted in some areas, but since the presence or absence of a check cannot be visually checked, there is a risk of a check being omitted due to equipment trouble, which was inconvenient for both administrators and users. .

Also, various prepaid cards include magnetic cards and I/O cards.
Although C cards are used, the recorded contents cannot be viewed directly, so it is not possible to easily check the payment amount or balance.
There was a problem in terms of guaranteeing the content to users.

Previously, there were methods to print usage details on the card each time the card was used, or to display the approximate value of the remaining amount by punching a hole, but these methods could not erase the records, so there was a limit to the number of times the card could be used. It is not suitable for cards with a large number of balances or cards that require accurate balance display.

Therefore, the present applicant first proposed a method that can repeatedly create and erase visible records on commuter passes and various prepaid cards.

One method is to use a card 1 having a smooth layer 11 made of synthetic resin on its surface, and to form a frosted surface 15 that can be erased by heat on the smooth layer 11, as shown in a cross-sectional view in FIG. Then, the frosted surface 15 is partially heated by a thermal head to return it to a smooth surface, and a visually visible image 12 is created due to the contrast between the frosted surface and the smooth surface, that is, the difference in light reflectance, etc., and the zero image is erased. At this time, the entire surface is again frosted as shown in the cross-sectional view in FIG.

(Problem to be Solved by the Invention) However, when a frosted card surface is heated and printed with a thermal head, if the thermal head is not in contact with the card, it will return to its original smooth surface, or the thermal head will normally return to its original smooth surface. When the card is brought into contact with a certain pressure, as shown in FIG. 5, an unevenness 201 corresponding to the thermal dot is formed. When an attempt is made to erase this record, as shown in FIG. 6, part of the unevenness 202 formed by the thermal head remains on the frosted surface, giving the appearance that some letters remain. In particular, when the unevenness 201 formed by the thermal head becomes deeper than the frost on the frosted surface 15, the remaining characters become significant.

(Means for Solving the Problems) The present invention provides a method for recording on cards such as commuter passes, admission tickets, and various prepaid cards using a thermal head on a frosted surface in order to record visually visible records that can be repeatedly formed and erased. , which eliminates print residue when erasing.

The present invention will be explained in detail below with reference to the drawings.

FIG. 1 is a perspective view showing an example of a card used in the method of the present invention, and FIGS. 2 to 4 are sectional views illustrating the method of the present invention.

To explain the card used in the present invention with reference to FIG. 1, the card 1 is made by laminating a smooth layer 11 made of synthetic resin and a support layer 12 such as a strong polyethylene terephthalate sheet or paper. is the recording unit 13,
The other surfaces are printed 14 to display necessary explanations and decorative designs. Further, the card l is usually provided with a magnetic layer, etc., and has functions for storing information, performing calculations, etc.

In the method of the present invention, first, as shown in FIG.
On the smooth recording portion 13 of , unevenness 21 equivalent to the unevenness formed by heating with a thermal head is formed.

The unevenness 21 is formed at a temperature T3 higher than a temperature T2 during image formation, which will be described later. That is, this unevenness 21 is
It is thermally stable and will not be erased by subsequent imaging. Note that this temperature T3 is preferably set to a temperature below the melting point of the resin in order to prevent adhesion.

Methods for forming the unevenness 21 include a method of solid printing using a thermal head heated to a high temperature, and a method of embossing using an embossing plate provided with unevenness. The unevenness 21 is
Usually 150 pieces/8 mm or less, especially 100 pieces/8
It is preferable to set the roughness to less than mm.

Next, as shown in FIG.
A 70 stroke surface 15 is obtained by performing a 0 stroke (surface roughening) treatment.

By performing this frosting treatment at a temperature T1 that is in the range of not less than the glass transition temperature ('I''g) and not more than the melting point (Tm) of the resin of the smooth layer 11, the frosted surface attempts to return to its original smooth surface by heating. At temperatures lower than Tg, frosting will only produce distortion, or the resulting distortion will be rapidly released without heating.
At higher temperatures, the resulting frost has no distortion and cannot be erased even by reheating, thereby failing to achieve the objective of the invention.

In the case of non-quality resins, they often do not show a clear Tm, but in that case, the flow start temperature is defined as Tm, and in the case of crosslinked resins that generally do not show a Tm, the flow start temperature (
If the mixed resin or copolymer resin exhibits two or more Tg's, the higher Tg may be used as the standard.

As for the condition of the frost, the surface roughness of the frost surface 15 is 1 to 1 according to the 10-point average roughness Rz of JIS-B-0601.
It is preferable that the thickness is 0 μm and the number of peaks is in the range of 200 to 1000 pieces/mm.

If Rz is less than 1 μm, even if an image is formed on the frosted surface during recording, it is difficult to determine the presence or absence of the image.
If it exceeds this, it will take time for smoothing during recording and it will be necessary to increase the heating temperature, which is disadvantageous in terms of equipment.

The frost treatment can be performed, for example, by crimping a frost plate.

After the frosting process, a portion 22 of the previously formed unevenness 21
remains, but it is dispersed throughout and the area is small, so
The frosted appearance is not much different from the case where the unevenness 21 is not formed.

To record on this card, as shown in FIG. 4, the frosted surface 15 of the card is partially heated by a thermal head at a temperature T2 higher than the frosting temperature T2. Then, only the heated part becomes as shown in Figure 2.
The surface returns to a smoother surface compared to the frosted surface 15, and images 2 such as letters, figures, symbols, etc. appear due to the difference in reflectance from the frosted surface.

A thermal head is a matrix-like head made up of a collection of minute heating elements, and only the necessary points are heated by an external signal.

When a thermal head is used to form an image made up of a large number of points, the boundaries become clear and the image becomes clearer.
The resolution will also be higher.

In addition, by using a thermal head, it is possible to print not only predetermined images but also images of arbitrary characters and sizes as needed, and it is also possible to record images after displaying and checking them on a CRT display, etc. can.

When erasing an image, the entire surface of the recording surface 13 is frosted to erase the image 2. This frost treatment, like the first frost treatment, is performed at a temperature above Tg and below Tm of the synthetic resin to retain distortion inside. As a result, the card 1 returns to the state shown in FIG. 3 before image formation, and can be used repeatedly thereafter.

Here, in the recording area after image erasure shown in FIG. 3, some portions 22 of the unevenness 21 remain as described above, but they do not remain concentrated in the image area but are dispersed throughout the area, so this is a big deal. It is very inconspicuous and can solve the problem of remaining print.

In the present invention, the resin constituting the smooth layer 11 includes polyvinyl chloride, polystyrene, polymethyl (meth)acrylate, polyethylene terephthalate, polyamide,
Various resins such as ABS resin or copolymer resins thereof can be used alone or in combination. Among these, non-grade resins such as polyvinyl chloride, polystyrene, and polymethyl (meth)acrylate are preferred because they are easy to handle.

Furthermore, crosslinkable acrylic resins, crosslinkable urethane resins, or the various resins mentioned above can be treated with crosslinking agents, electron beams, gamma rays, etc.
It is also possible to use a resin that has been crosslinked to the extent that it does not lose its heat fluidity.

These resins preferably have a Tg in the range of 50 to 140°C.

The thickness of the smooth layer 11 is usually in the range of 5 μm to 3 mm,
There is no particular limit to the overall thickness of the card 1, but it is 0.1
It is approximately 3 mm.

As this smooth layer 11, a film or sheet formed by extrusion molding or the like may be used, or it may be formed by coating.

According to the method of the present invention, the main information recorded on the magnetic layer etc. can be visually displayed as an image, and the information can be recorded at the time of entry and erased at the time of exit. Check entry and exit to and facilities,
It is possible to record and display the amount spent and balance on prepaid cards used at restaurants, shops, vending machines, etc.

(Effects of the Invention) According to the method of the present invention, it is possible to repeatedly form and erase visible records on a card, and by forming unevenness on the card in advance, it is possible to eliminate print residue when erasing records. can.

(Example) A polyethylene terephthalate sheet (188 μm thick) was used as the support layer 12, and a smooth layer 11 (15 μm thick colorless transparent polyvinyl chloride resin, 7g 70°C
, Tm 202°C), and a recording section 1 of 1010×20
The card (commuter pass) shown in FIG. 1 was created by printing 14, except for 3.

Then, the following process was performed on that card.

(a) First, a thermal head is applied to the entire surface of the recording section.
Voltage 10V, energizing time 3ms/dot, head contact pressure 5
Solid printing was performed under conditions of 00 g/cm and a head temperature of 300°C (card temperature of approximately 180°C).

The number of unevenness formed was 128/8 mm, and the height of the unevenness was about 3 μm.

(b) On the recording surface, Rz is 3)tm, the number of peaks is 350a
Frosting was carried out using a frosted plate with a frosted surface of 1/8 mm under conditions of a temperature of 170°C (card temperature of about 100°C), a pressurization time of 0.3 seconds, and a pressure of 20 kg.

The formed frost had an Rz of 2°5 μm and a number of ridges of 300/8 mm.

(C) Next, use a thermal head to increase the head temperature to 200
The characters were printed under the same conditions as in (a) except that the card temperature was approximately 130°C.The characters were clear and easily visible.9(d) Same as in (b) above. hand,
The recording section was frosted to erase the characters.

As a result, the printed characters were completely erased and no remaining print was observed.

For comparison, without performing the operation in (a), the above (b) ~
When the same process as in (d) was performed, the print was not completely erased even by the process in (d), and some remaining print was observed.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an example of a card used in the method of the present invention, FIGS. 2 to 4 are sectional views explaining the method of the present invention, and FIGS.
Figure 6 is a cross-sectional view showing the comparison method. 1...Card 11...Smooth layer 15...
Frosted surface 2... Image 21... Unevenness Figure 1 Patent applicant Mitsubishi Plastics Co., Ltd. agent Patent attorney Kumi Kondo t(・

Claims (1)

[Claims] A frosting method that retains distortion by forming a smooth layer of synthetic resin on at least a portion of the surface of the card, and frosting the smooth layer at a temperature T_1 that is above the glass transition temperature and below the melting point of the resin. In forming an image by partially heating the frosted surface with a thermal head at a temperature T_2 higher than the temperature T_1 of the frosting process, the smooth surface is heated with a thermal head before the frosting process. The unevenness is equivalent to the unevenness formed by heating.
A method for visually recording on a card, characterized in that the recording is performed at a temperature T_3 higher than the heating temperature T_2.