JPH09175039A - Rewritable heat-sensitive recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To print and rewrite physically by utilizing the softening and curing by the temperature variation of thermoplastic resin by forming the fine recessed and projected patterns on the whole or a partial area of a recording layer, and printing on the area by a thermal head or the like to erasing the fine recessed and projected patterns and record characters and the like. SOLUTION: A hot plate of mat tone on which fine recessed and projected patterns such as satin, sand-pattern and the like are formed is-contacted on the surface of a recording layer 13 of thermoplastic resin to form fine recessed and projected patterns, and the processing for converting this section into a translucent area is carried out. The printing T to a medium, can therefore, be carried out by melting the fine recessed and projected patterns by heating directly a thermal head to the temperature of 100-120 deg.C, smoothing and solidifying the section and making the section transparent. The characters and the like developed on the recording layer of thermoplastic resin are converted into a translucent area by forming again the fine recessed and projected patterns by the hot plate. That is, printing and erasing can be carried out repeatedly.

Description

Detailed Description of the Invention

[0001]

INDUSTRIAL APPLICABILITY The present invention provides a recording layer made of a thermoplastic resin on a support, and a fine concavo-convex pattern is provided on the surface of the support. The present invention relates to a thermosensitive recording medium.

[0002]

2. Description of the Related Art Thermosensitive recording media of this type include thermoplastic resins such as polyvinyl chloride and higher fatty acids dispersed in the resins as described in JP-A-55-154198. There is known a structure in which a recording layer containing an organic low molecular weight substance as a main component is provided on a support.

This heat-sensitive recording medium is constructed by utilizing the property that the light absorption property (light scattering property) of the recording layer reversibly changes depending on temperature. That is, this recording layer has the property of changing at two temperatures T1 and T2 (where T1 <T2) higher than a specific temperature near room temperature, and after heating the recording layer to a certain temperature or higher and holding it, When cooled below a specific temperature, it becomes cloudy and its light scattering property increases to the maximum light-shielding state, while the recording layer in this cloudy state is heated above T1 and below T2 and held, and then cooled below a specific temperature near room temperature. Then, its light-scattering property is reduced and it becomes transparent. Moreover, the maximum light-shielding state and the transparent state of the recording layer can be stably maintained below a specific temperature, and these states can be reversibly changed. By setting, it can be differentiated from the other state and can be used as a rewritable recording medium.

[0004]

However, in this heat-sensitive recording medium, there is an upper limit and a lower limit in the temperature range in which the recording layer can be made transparent, and therefore, T1 or more in a part or the whole of the recording layer in the cloudy state. There is a problem in that temperature control is easily influenced by the environment and medium when heating the temperature below T2 to make it transparent. That is, in this type of heat-sensitive recording medium, it is possible to make the cloudy base into a transparent state by using a heating means such as a thermal head, but as described above, the temperature at which the base becomes transparent is limited to within a certain range. Therefore, it is difficult to keep the heating temperature of the thermal head or the like within the set temperature range.

In view of the above, the present invention utilizes softening and curing of a thermoplastic resin as a recording layer due to temperature change to physically perform printing so as to have rewritability, and is simple and inexpensive. An object of the present invention is to provide a rewritable thermal recording medium that can be rewritten.

[0006]

In order to achieve the above object, the present invention provides a support with a reflective layer formed by metal vapor deposition or the like and a recording layer formed of a transparent thermoplastic resin, and the surface of a support such as a plain material. By forming a fine uneven pattern on the entire surface or a partial area of the recording layer with a hot plate provided with a fine uneven pattern, it is possible to print characters etc. on the fine uneven pattern by a thermal head or the like. A rewritable thermosensitive recording medium characterized by the following.

The rewritable heat-sensitive recording medium is characterized in that the printing is erased by forming a fine concavo-convex pattern again on the printed recording layer.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The rewritable thermosensitive recording medium of the present invention will be described below in detail based on one embodiment. The rewritable heat-sensitive recording medium of the present invention is a laminated body in which a reflective layer such as an aluminum foil or an aluminum vapor-deposited layer and a recording layer made of a transparent thermoplastic resin are provided on a support, and the surface of the recording layer is By forming a fine uneven pattern on the recording layer with a matte heating plate having a fine uneven pattern such as the ground, that portion becomes a semi-transparent region. When printing on this semi-transparent area by heating with a thermal head, etc., the fine uneven pattern formed on the surface of the recording layer by the thermoplastic resin is partially melted by the heat of the thermal head to be smoothed and solidified. Becomes transparent, and the contrast of the semi-transparent portion and the transparent portion is emphasized by the lower reflective layer, so that the shape of characters and the like can be recognized. Furthermore, if a concavo-convex pattern such as a plain material is formed again on the printed recording layer by a heating plate to make it a semi-transparent area, the transparent parts such as printed characters are erased and the original medium is restored, so that the thermal medium is re-heated. Printing becomes possible with a head or the like, and the thermal recording medium can be repeatedly used.

As shown in FIG. 1, the rewritable thermosensitive recording medium of the present invention is a laminated body composed of a support 11, a reflective layer 12, and a recording layer 13 made of a transparent thermoplastic resin. The support 11 may be polyethylene terephthalate, hard vinyl chloride resin or the like, which is usually used for prepaid cards, credit cards and the like.
The reflection layer 12 is provided on one surface of this support by an aluminum foil or an aluminum vapor deposition layer. This reflective layer is for improving the visibility of characters and the like developed by printing, and it is desirable that the surface is as smooth and mirror-like as possible.

As the recording layer 13 made of a thermoplastic resin provided on the reflecting layer 12, there are many resins such as vinyl chloride resin, polyvinylidene chloride and polyethylene which can be used, but they are as transparent as possible and have a maximum operating temperature. Is 80
A resin having a low temperature of about 100 ° C is preferable.

As shown in the sectional view of FIG. 2 and the plan view of FIG. 3, on the surface of the recording layer 13 made of the thermoplastic resin of this medium,
A semi-transparent area 15 is formed by a fine uneven pattern. In this semi-transparent area, a mat-like hot plate having a fine uneven pattern such as a plain material and a grain on the surface is pressure-bonded to form a fine uneven pattern. Is formed on the recording layer, and this portion is a semi-transparent region. The semi-transparent region 15 can be appropriately provided on the entire surface or a partial region of the thermoplastic resin layer, but by leaving a margin (non-translucent portion) in the peripheral portion or a part thereof, printing is performed on this portion. It is possible to provide a picture, characters, etc. that cannot be erased.

The printing T on this medium is performed by directly printing and recording on the medium by a heating means such as a thermal head or a laser, and a transfer ribbon or the like is formed on a semi-transparent region having a fine concavo-convex pattern such as a plain material and a grain. By directly heating the thermal head at 100 to 120 ° C. without any interposition, the fine concavo-convex pattern is melted, and this portion becomes smooth and becomes transparent when solidified. As a result, a transparent character shape is developed in the semitransparent region, the contrast between the semitransparent and transparent portions is emphasized by the lower reflective layer, and the shape of the character or the like can be clearly recognized.

Further, by forming a fine relief pattern on the recording layer of the printed and recorded thermoplastic resin by the hot plate again, the expressed characters are erased and a semi-transparent region due to the relief pattern is formed. Therefore, a rewritable heat-sensitive recording medium that can be repeatedly printed and erased can be obtained.

[0014]

EXAMPLES Specific examples will be described below.

<Example 1> As a support, a thickness of 0.20
After applying a corona discharge treatment to a polyethylene terephthalate sheet of mm, a 500 Å-thick aluminum vapor deposition layer was provided by a vacuum vapor deposition method to form a reflection layer. A vinyl chloride resin was extruded on the reflective layer and laminated by a lamination method to obtain a laminate having a recording layer of a thermoplastic resin having a thickness of 20 μm. On the surface of the thermoplastic resin layer of this laminate, a hot plate having a fine relief pattern of the plain material was pressed and heated and pressed to transfer the fine relief pattern of the plain material.
The surface of the thermoplastic resin layer on which this plain material was transferred was translucent (matte tone), and the other portion (margin) was a transparent heat-sensitive recording medium.

Next, the recording is performed by printing with a thermal head in the semi-transparent area. When heating is performed with the thermal head, the fine uneven pattern of the plain material is melted into a character shape and the portion is smoothed. When solidified, only that part became transparent, and the contrast was emphasized by the reflective layer so that the characters could be recognized.

Further, the characters are erased by transferring the fine uneven pattern of the plain material again onto the recording layer made of the thermoplastic resin on which the characters are recorded, by the hot plate used previously, and the characters are erased, and the original semi-transparent area is formed. Has become a medium having.

<Example 2> 0.5 mm thick as a support
Using a vinyl chloride sheet of, a 0.015 mm-thick aluminum foil is attached to one surface of this support through an adhesive for vinyl to form a reflective layer, and the same adhesive as above is applied on the reflective layer. A polyethylene sheet having a thickness of 0.12 mm was attached to form a recording layer made of a thermoplastic resin. Next, a hot plate having a fine grain-shaped uneven pattern was pressed against the surface of the recording layer and heated and pressed to transfer the fine grain-shaped uneven pattern. The surface of the recording layer to which this uneven pattern was transferred became a semi-transparent (matte) region, and a medium was obtained in which the other portions remained transparent.

Printing and erasing of this medium were carried out in the same manner as in Example 1, and equivalent quality was obtained.

[0020]

As described above, the present invention has the following effects. That is, since the thermosensitive recording medium of the present invention records and displays by a physical change without using a color former or a magnetic substance, there is no fear of fading or change due to magnetism, and it can be manufactured at low cost.

Further, the heat-sensitive recording medium of the present invention can easily change the heat-sensitive characteristics of the thermoplastic resin which is the rewritable recording layer. That is, as long as it has thermoplasticity, the material can be selected according to the intended use, and the softening point at the time of printing can also be selected.

Further, since the thermal recording medium of the present invention can easily set the erasing temperature, it can be repeatedly used. That is, in forming a semi-transparent area with a fine uneven pattern and erasing a print, the heating temperature may be equal to or higher than the softening point of the thermoplastic resin layer, so that the conventional recording layer (white turbid transparent type)
As described above, since it is not necessary to control the heating temperature in a certain narrow range, printing and erasing can be easily performed.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a cross section of a laminated body showing an example of a rewritable thermal recording medium of the present invention.

FIG. 2 is a cross-sectional view showing an example in which a rewritable thermosensitive recording medium of the present invention is provided with a semitransparent region.

FIG. 3 is a plan view showing an example in which a rewritable thermosensitive recording medium of the present invention is provided with a semitransparent region.

FIG. 4 is an explanatory diagram showing characters developed by printing with a thermal head in a translucent area of the rewritable thermosensitive recording medium of the present invention.

[Explanation of symbols]

 11 ... Support 12 ... Reflective layer 13 ... Thermoplastic resin recording layer 15 ... Semi-transparent area with fine uneven pattern T ... Printing (expressed characters)

Claims (2)

[Claims] 1. A recording layer of a reflective layer formed by metal deposition or the like and a recording layer formed of a transparent thermoplastic resin are provided on a support, and the surface of the recording layer is provided with a fine uneven pattern such as a plain material. By forming a fine concavo-convex pattern on the entire surface or a part of the area and printing with a thermal head or the like on the fine concavo-convex pattern,
A rewritable heat-sensitive recording medium, which is capable of recording characters and the like by erasing fine uneven patterns. 2. The rewritable thermosensitive recording medium according to claim 1, wherein the printing is erased by forming a fine uneven pattern again on the printed recording layer.