JP2003118233A - Reversible heat-sensitive recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a reversible heat-sensitive recording medium coating layer from dropping and a scum from being adhered and stained in printing, cutting and other processing steps. SOLUTION: A filling layer is formed on the reversible heat-sensitive recording medium and a part in which the recording layer is not formed for flattening the surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rewritable color-developing recording medium, and more particularly to a reversible thermosensitive recording medium which is excellent in processability and capable of producing a high quality final product.

[0002]

2. Description of the Related Art In recent years, reversible thermosensitive recording media capable of recording and erasing images have been attracting attention. A typical example thereof is a reversible thermosensitive recording medium comprising a colorless or light-colored leuco dye and a reversible color developer that develops a color of the leuco dye by heating and then reheats it to decolorize it. The reversible color developer melts in this medium due to the heat of the heat sensitive head, reacts with the leuco dye, and is rapidly cooled to be in a colored state. The reversible color developer and leuco dye are crystallized by rearranging the color-developed state again by heating again and gradually cooling, thereby erasing the color. The erasing temperature can be lower than that at the time of recording because the molecules are rearranged. As such a recording material, JP-A-6-2109
54, JP-A-6-171225, JP-A-7
In Japanese Patent Laid-Open No. 68933 and Japanese Patent Laid-Open No. 7-68934, it is possible to record and erase an image with good contrast.
A reversible color developer capable of holding a stable image over time in an environment of daily life has been reported and is now in practical use.

In this reversible thermosensitive recording medium, a thermosensitive head is usually used for recording. In this case, when recording and erasing an image by heating are repeated, the surface is rubbed while being heated, so that the surface of the recording layer is scratched. When it occurs and becomes aggravated, there is a problem that a uniform image cannot be recorded. On the other hand, JP-A-6-344673 and JP-A-8-
Japanese Patent No. 156410 proposes to provide a protective layer on the surface of such a reversible recording material to reduce scratches on the surface of the recording layer when a thermal head is used.

As another recording method, a non-contact recording method using light such as a laser has been reported. Japanese Unexamined Patent Publication (Kokai) No. 5-8537 reports a method of recording and erasing by irradiating light by providing a heat mode optical recording layer on a reversible thermosensitive medium. In addition, JP-A-2000-159
Japanese Patent No. 31 discloses a method of sandwiching a reversible thermosensitive recording layer with a light absorption conversion layer.

This reversible thermosensitive recording medium has been put to practical use in applications such as cards. In a general manufacturing method, a polyethylene terephthalate film is usually used as a support, and a reversible thermosensitive recording layer is formed on the film. A protective layer is formed on top. In addition, an undercoat layer may be formed under the recording layer in order to improve the characteristics of the medium or to impart another characteristic, or an intermediate layer may be formed between the recording layer and the protective layer. The thickness of the recording layer is usually 5 μm or more, and the protective layer is usually 2
The thickness of the entire layer is 10 μm on the support.
Layers around m will be formed. The recording layer is mainly composed of a reversible color developer and a leuco dye, but the ratio of the adhesive contained in the recording layer is small due to the relationship of the recording sensitivity, and the intermediate layer or the protective layer for protecting the recording layer should be thin. preferable. Further, from the relationship of recording density, it is preferable that the recording layer is thick. That is, when the recording sensitivity and the recording density are emphasized, the entire layers are weakened. On the other hand, properties such as processability of the medium, durability against repeated recording and erasing, physical strength when finished into a product, chemical resistance, etc. are required. Conversely, a strong layer is required to meet these requirements. To be

In the case of laser recording, the smaller the laser output is, the more preferable in terms of safety and the size of the apparatus. Therefore, as a reversible thermosensitive medium, it is necessary to increase the sensitivity of the recording layer as much as possible, but if this is promoted, the recording layer becomes brittle for the above-mentioned reason. In the case of laser recording, it is possible to make the protective layer thicker by selecting a material that allows the laser to pass through, but if force such as cutting is applied, the protective layer and the intermediate layer will not collapse the recording layer. It cannot be prevented.

When a card with a rewrite display is manufactured using this reversible thermosensitive recording medium, the medium is printed,
Although the cutting and other processing steps are performed, the coating layer is particularly fragile due to the brittleness of the recording layer, and the debris that has fallen off pollutes the manufacturing machine and the conveying device. Contamination in the process becomes an obstacle when manufacturing precision card products such as IC cards. Further, although it looks normal immediately after finishing the final product, the coating layer at the edge portion of the product falls off together with the upper printing layer during use.

When a resin film is used as a support for the reversible thermosensitive recording medium, a resin film having a high melting point such as polyethylene terephthalate is usually used because the surface of the support is easily damaged by heat and pressure during thermosensitive recording. . Such a film with a high melting point is not suitable for molding as compared with a film made of vinyl chloride resin or ABS resin because the resin is hard to make a card that requires molding such as embossing or magnetic tape embedding. .

[0009]

DISCLOSURE OF THE INVENTION The present invention is a reversible thermosensitive recording medium in which a colorless or light-colored leuco dye and a leuco dye are usually colored by heating and then decolored by reheating the medium, which is excellent in processability. The task is to develop a manufacturing method for.

[0010]

As a result of earnest research to solve the above-mentioned problems, the present inventor has found a method of manufacturing a reversible thermosensitive recording material and a recording method which are excellent in workability of processing and high in quality. Invented That is, the recording layer is partially formed in consideration of post-processing, and the recording layer portion is embedded in resin,
Alternatively, it is to be encapsulated in resin to protect the weak recording layer and to make the medium surface flat. Furthermore, a reversible thermosensitive recording material that can be easily molded can be obtained by selecting a material that can be easily molded into a support sheet or an oversheet. When the recording layer is sealed with a resin sheet or the like, at least one of the upper and lower resin sheets of the recording layer needs to be transparent, and a laser is suitable for recording and erasing. It is conceivable to use a photothermal conversion material in the vicinity of the recording layer.

First, as a first method, a recording layer is partially formed on a support, and a filling layer is formed on a portion where the recording layer is not formed. According to this method, it is possible to flatten the surface of the medium and prevent the coating layer from falling off due to cutting or rubbing during post-processing, and it is possible to supply a medium having excellent processability. It is also possible to attach an oversheet on this medium to enclose the recording layer.

In the second method, a sheet made of a resin which is easy to mold is selected as a support, a recording layer is partially formed on the sheet, and then a heat press or the like is used to apply heat and pressure to the medium. In addition, it is a method in which the recording layer is embedded in a support resin and flattened. The medium thus obtained has the same effects as those of the first method and is also suitable for molding. It is also conceivable to attach an oversheet on this medium and enclose the recording layer and the like in a resin.

The third method is to select a support and / or an oversheet made of a resin which can be easily molded, form a recording layer on the support and form an oversheet on the surface of the recording layer. And the recording layer is embedded in the resin by hot pressing or the like. The resulting medium has excellent post processability and processability. In this case, the support and / or the oversheet are transparent, and a laser is preferable for recording and erasing.

[0014]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in detail with reference to the drawings. FIG. 1 shows the first method. A recording layer (2) is formed on a part of the surface of the support (1), and a protective layer (3) is usually formed on the recording layer (2), and a filling layer (4) is provided on a portion without the recording layer. . An undercoat layer may be formed under the recording layer, or an intermediate layer may be provided between the protective layer and the recording layer. Further, these layers may be provided only on the recording layer or on the entire surface. The filling layer is formed at the same height as the portion where the recording layer is provided. Its purpose is to protect the recording layer,
This is to prevent the recording layer from falling off due to cutting or the like in a later step of the present recording medium, and to make the thickness of the medium uniform. It is also conceivable that the filling layer also serves as a protective layer and the entire surface is covered.

Next, the second method is shown in FIG. The recording layer (2), the protective layer (3) and the barrier layer (5), which are partially formed on the support (1), are embedded. In addition to these layers, it is possible to form other layers as needed. It is conceivable that the layers other than the recording layer may be formed only on the recording layer portion or on the entire surface. When the protective layer is formed, that part is on the support, but by applying heat and pressure using a heat press, the recording layer and the protective layer are embedded in the support resin. The surface of the medium is flattened.

Next, the third method is shown in FIG. The recording layer (2) partially formed on the support (1) and the barrier layers (5) above and below the recording layer are the support and the oversheet (6).
Embedded in. In addition to these layers, it is possible to form other layers as needed. It is conceivable that the layers other than the recording layer may be formed only on the recording layer portion or on the entire surface. At the time of stacking with the oversheet, these layers are in the shape of riding on the support, but by heat pressing etc., these layers are confined in the resin of the support and the resin of the transparent resin sheet, and the surface of the medium is also flat. Be converted. This figure shows the case where both the support and the oversheet are made of a material that is easy to mold.If either the support or the oversheet is made of a resin that is easy to mold, one side of the recording layer is Only embedded in. A laser is preferable for recording and erasing the medium. In that case, it is conceivable to add the photothermal conversion material to the recording layer or the barrier layer or other layers.

Next, the present invention as a whole will be described in detail. The recording layer of the present invention comprises a leuco dye and a reversible color developer. The method for forming the recording layer is not particularly limited, but a printing method can be considered. The printing machine may be a gravure printing machine, an offset printing machine, a screen printing machine, or the like, and all existing printing machines of the type such as letterpress, planographic printing, intaglio printing, and stencil printing can be used. Alternatively, a method of using a coating machine can be considered.

The leuco dye used in the recording layer of the present invention is represented by those generally used for pressure-sensitive recording paper and heat-sensitive recording paper, but is not particularly limited, and triaryl methane compounds and xanthenes are not particularly limited. Compounds, diphenylmethane compounds, thiazine compounds, spiro compounds, etc. are considered. It is also conceivable to use a mixture of these compounds.

The reversible color developer used in the recording layer of the present invention includes, for example, a phenol compound proposed in JP-A-6-210954, JP-A-11-58963.
The compound proposed in the publication is considered, but the compound is not particularly limited as long as it is a compound capable of causing a reversible color change in the leuco dye by heating.

The support in the first method is not particularly limited, but a usual plastic film,
Paper, metal, etc. can be considered. It is also possible to form the filling layer by the first method at once, or to form the filling layer having the same composition or different compositions in several times.
The forming method is not particularly specified, but for example, a printing method can be considered. Printing machines are gravure printing machines, offset printing machines,
It is possible to use all existing printers such as screen printers such as letterpress, planographic, intaglio, and stencil. It is also possible to use a coating machine.

It is preferable that the filling layer firmly adheres to the support and the filling layer itself has a high internal strength. The resin used for the filling layer is not particularly limited, and a known resin can be used. For example, it is conceivable to use adhesives or resins used for various printing inks or coating liquids for coating machines. In addition to the resin, well-known pigments, dyes and other additives used for printing inks and coating liquids for coating machines can be added to the present filling layer.

A support used in the second method, and a third
The support and / or the oversheet in the method (1) is preferably a sheet using a resin that is easy to mold. The melting point of the resin is preferably lower than the melting point of the reversible color developer used in the recording layer. For example, it is a sheet made of vinyl chloride resin, ABS resin or the like having a melting point of 160 ° C. or less, which is easily molded. When a resin sheet having a melting point higher than that of the reversible developer is used, it is necessary to increase the temperature and pressure of the hot press, and as a result, the reversible developer may be eluted from the recording layer. However, one of the support and the oversheet of the third method may be made of a material that does not take molding processability into consideration. In that case, the same support as the first support is conceivable.

The barrier layer in the second and third methods is
Prevents the support and oversheet from melting due to heat during recording. In order to prevent this dissolution and to maintain the durability of the main coating layer during hot pressing, the resin such as the adhesive used in these layers should have a higher melting point than that of the reversible developer used in the recording layer. It is preferable to include. As the materials used for these layers, known polymer compounds, resins and pigments obtained by crosslinking these polymer compounds with heat, UV, EB as necessary, and other additives can be used. The method for forming the barrier layer is not particularly limited. The barrier layer needs to cover the recording layer because of its role, but a method of covering the entire surface of the support including the recording layer is also conceivable.

When an oversheet is used on the recording layer by the third method, the first method, or the second method, recording and erasing with a laser is suitable. When a laser is used, it is conceivable to use a photothermal conversion material for the recording layer or a barrier layer near the recording layer. The photothermal conversion material is not particularly limited, but for example, platinum, gold, silver, copper,
Titanium, silicon, chrome, nickel, germanium,
There is a metal such as aluminum or a semi-metal group, and these are photothermally converted by forming a thin film such as a vapor deposition film. Further, as the dye-based photothermal conversion material, azo dyes, cyanine dyes, naphthoquinone dyes, anthraquinone dyes, squarylium dyes, phthalocyanine dyes, naphthoquinone dyes, porphyrin dyes, indigo dyes, dithiol complex dyes , Azurenium dyes, quinone imide dyes, quinone diimine dyes, and the like. Furthermore, organic pigments and the like can also be used as the photothermal conversion material. These photothermal conversion materials are selected according to the wavelength of light used for recording / erasing.

[0025]

EXAMPLES The present invention will be described in more detail below, but the present invention is not limited to these examples. All parts shown below are based on weight.

(A) Preparation of coating liquid for recording layer, 20 parts of 3-di-n-butylamino-6-methyl-7-anilinofluorane as leuco dye, N- [3- as reversible developer
(P-Hydroxyphenyl) propiono] -N'-n-
Octadecanohydrazide 100 parts, vinyl chloride vinyl acetate copolymer resin (trade name, VAG
H, manufactured by Union Carbide Co., Ltd.), and 600 parts of toluene as a solvent are mixed and crushed by a ball mill for 24 hours.
A coating liquid for a reversible heat-sensitive recording layer that developed black was prepared.

(B) Preparation of coating liquid for protective layer, 90 parts of Aronix M8030 (manufactured by Toagosei Chemical Industry Co., Ltd.), 5 parts of N-vinyl-2-pyrrolidone, 5 parts of Irgacure 500 (manufactured by Nippon Ciba Geigy), Mizukasil P- 527 (manufactured by Mizusawa Chemical Co., Ltd.) was mixed and sufficiently stirred to obtain an ultraviolet curable protective layer coating liquid.

(C) Preparation of coating liquid for filling layer, 100 parts of vinyl chloride / vinyl acetate copolymer resin (trade name, VAGH, manufactured by Union Carbide), 10 parts of Mizukasil P-527 (manufactured by Mizusawa Chemical Co., Ltd.), as a solvent Mix 200 parts of toluene,
It was crushed for 24 hours with a ball mill to obtain a filling layer coating liquid.

(D) Preparation of Coating Liquid for Barrier Layer-1 100 parts of water was added to 50 parts of precipitated calcium carbonate and 2 parts of sodium hexametaphosphate and dispersed by a homogenizer. To this, add 100 parts of 10% aqueous solution of polyvinyl alcohol,
The mixture was mixed well to obtain a coating liquid for barrier layer-1.

(E) Preparation of Coating Solution for Barrier Layer-2 100 parts of water was added to 50 parts of precipitated calcium carbonate and 2 parts of sodium hexametaphosphate, and dispersed with a homogenizer. To this, 30 parts of styrene butadiene latex (trade name, Nipol LX204, solid content 41%, manufactured by Zeon Corporation) was added and mixed well to obtain a coating liquid for barrier layer-2.

(F) Preparation of coating liquid for light-heat conversion layer, 100 parts of titanyl phthalocyanine as light-heat conversion material, polyester resin (trade name, Byron 200, manufactured by Toyobo Co., Ltd.) 10
0 part, 2 parts of isocyanate (trade name, Coronate L, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 500 parts of toluene as a solvent were mixed and mixed to prepare a coating solution for a photothermal conversion layer.

Example 1 A white polyester film (size 20 cm square) having a thickness of 188 μm was used as a support, and the recording layer coating liquid prepared in (A) was dried in a shape of width 30 mm × length 30 mm. Of about 5 μm and then dried, and the application liquid for protective layer prepared in (B) was applied thereon to about 3 μm and dried to form a layer. Further, by using the filling layer coating liquid prepared in (C), the thickness becomes 8 μm,
A reversible thermosensitive recording medium was prepared by coating on the entire surface except the portion where the recording layer was formed and drying. When the recording layer forming portion of this medium was centered, it was punched out into a card shape (width 54 mm x length 85.6 mm), and the state of collapse of the coating layer on the cutting surface was observed with a microscope, and the cutting surface was in a good state. It was Using this thermal printing device TH-PMD manufactured by Okura Electric Co., Ltd., a thermal head having a printing density of 8 dot / mm, a printing cycle of 4 ms,
Pulse period 2ms, printing energy 0.6mJ / dot
When the recorded color image was recorded under the conditions of No. 1 and the recording density was measured using a densitometer Macbeth RD918, it was 1.1. Further, the obtained color recorded image portion was erased under the conditions of a heat stamp at 130 ° C., a stamp pressure of 1 kgf / cm ² and a contact time of 1 second, and the erase density was measured to be 0.12. The above recording and printing were set as one cycle, and 100 cycles were repeated. The recording density at the 100th time was 1.1, and the erasing density was 0.13. No deterioration in print density and erase density due to repetition was observed. When the recorded portion of the medium at the 100th time was observed with a microscope, no abnormality was found.

Example 2 A white vinyl chloride resin sheet (size 20 cm square) having a thickness of 280 μm was used as a support, and the coating liquid for barrier layer-1 prepared in (D) was formed in a shape of width 30 mm × length 30 mm. Apply it to a thickness of about 5 μm after drying and dry it. Then, apply the coating liquid for the recording layer prepared in (A) on it to a thickness of about 5 μm, dry it, and then create it on (B). After drying, the coating liquid for a protective layer was applied to a thickness of about 3 μm and dried to form a layer. This medium, in which three layers are formed in the same position, is heated at 130 ° C. under a pressure of 20 kg / cm ² for 3 times.
When the treatment for 0 minutes was performed, the portion where the recording layer was formed was embedded in the support resin, and a reversible thermosensitive recording medium having a flat surface was obtained. When the recording layer forming portion of this medium was centered and punched into a card shape and the state of collapse of the coating layer on the cut surface was observed with a microscope, the cut surface was in a good state. As a result of measuring the recording density and the erasing density by the same measuring method as in Example 1, the first recording density is 1.1 and the erasing density is 0.1.
In No. 3, at the 100th time, 1.1 and 0.13 were obtained, respectively. When the recorded part of the 100th medium was observed with a microscope, no abnormality was observed.

Example 3 A white vinyl chloride resin sheet (size 20 cm square) having a thickness of 280 μm was used as a support, and the coating liquid for barrier layer-1 prepared in (D) was formed in a shape of width 30 mm × length 30 mm. It is applied and dried so that the thickness after drying is about 5 μm, and the coating liquid for recording layer prepared in (A) is dried on it about 5 μm.
And then dried, and then the photothermal conversion coating liquid prepared in (F) is applied thereon to a thickness of about 2 μm, dried, and then for the barrier layer-1 prepared in (D). After drying, the coating liquid was applied to a thickness of about 3 μm and dried to form a layer. 280μ thick with this medium with 4 layers formed in the same position
m Transparent vinyl chloride resin sheets were overlaid and subjected to a heat press for 30 minutes at 130 ° C. and a pressure of 20 kg / cm ² to find that the coating layer was formed in the resin of the support and the transparent sheet. To obtain a reversible thermosensitive recording medium having a flat surface. Center the recording layer forming part of this medium,
When the material was punched into a card shape and the state of collapse of the coating layer on the cut surface was observed with a microscope, the cut surface was in a good state. This medium was recorded with a laser (wavelength, 830 nm) at a spot diameter of 100 μm, a feed rate of 40 mm / sec, and an irradiation light intensity of 50 to 200 mW, and the obtained color recording image was measured as a recording density using the above-mentioned densitometer. As a result,
It was 1.1. Further, the color recording image portion obtained is 20
It was 0.12. Further, the above recording and erasing are set as one cycle, and 100 cycles are repeated. The recording density at the 100th time is 1.1, and the erasing density is 0.
It was 13. When the recorded portion of the 100th medium was observed with a microscope, no abnormality was found.

Comparative Example 1 A white polyester film having a thickness of 188 μm was used as a support, and the recording layer coating liquid prepared in (A) was applied to the entire surface of the support so that the thickness after drying was about 5 μm. After drying, the coating solution for protective layer prepared in (B) was applied thereon to a thickness of about 3 μm and dried to form a layer. When the recording layer forming portion of this medium was centered and punched into a card shape and the collapsed state of the coating layer on the cut surface was observed with a microscope, chipping of the coating layer was recognized on the cut surface.

Comparative Example 2 A white polyester film (size 20 cm square) having a thickness of 188 μm was used as a support, and the recording layer coating solution prepared in (A) was dried in a shape of width 30 mm × length 30 mm. Of about 5 μm and then dried, and the protective layer coating liquid prepared in (B) was applied thereon to a thickness of about 3 μm and dried to form a layer. This medium, in which two layers were formed at the same position, was subjected to a heat press for 30 minutes at 180 ° C. and a pressure of 20 kg / cm ² , and the coated layer portion was not buried in the support. . Further, when the coated layer portion was observed with a microscope, the components outside the recording layer were found to be eluted.

Comparative Example 3 A white vinyl chloride resin sheet (size 20 cm square) having a thickness of 280 μm was used as a support, and the coating liquid for recording layer prepared in (A) was dried in a shape of width 30 mm × length 30 mm. To a thickness of about 5 μm and dried to form a layer. After drying the protective layer coating liquid prepared in (B) on it, about 3
A layer was formed by coating so as to have a thickness of μm and drying. Using a hot press, this medium with two layers formed in the same position
When a treatment was performed at 0 ° C. and a pressure of 20 kg / cm ² for 30 minutes, the portion where the recording layer was formed was embedded in the support resin,
A reversible thermosensitive recording medium having a flat surface was obtained. When the recording layer forming part of this medium was centered and punched into a card shape, the collapsed state of the coating layer on the cut surface was observed with a microscope,
The cutting surface was in good condition. As a result of measuring the recording density and the erasing density by the same measuring method as in Example 1, the first recording density was 1.1 and the erasing density was 0.13, but the printing density was 0.3 at the third time. The erasing density was 0.25 and could not be repeated. When the cross section of the third sample was observed with a microscope, elution of the support resin was observed.

Comparative Example 4 A white vinyl chloride resin sheet (size 20 cm square) having a thickness of 280 μm was used as a support, and the coating liquid for the barrier layer-2 prepared in (E) was formed in a shape of width 30 mm × length 30 mm. The layer is formed by coating and drying so that the thickness after drying is about 5 μm, and then the coating liquid for recording layer prepared in (A) is coated on it after drying to form about 5 μm, and then the layer is formed by drying. did. The coating solution for protective layer prepared in (B) was applied on it and dried to a thickness of about 3 μm, and dried to form a layer. This medium with three layers formed in the same position was heated at 130 ° C. using a hot press.
When treatment was carried out at a pressure of 20 kg / cm ² for 30 minutes, the portion where the recording layer was formed was embedded in the support resin, and a reversible thermosensitive recording medium having a flat surface was obtained. When the recording layer forming portion of this medium was centered and punched into a card shape and the state of collapse of the coating layer on the cut surface was observed with a microscope, the cut surface was in a good state. As a result of measuring the recording density and the erasing density by the same measuring method as in Example 1, the first recording density was 1.1 and the erasing density was 0.13, but the printing density was 0.5 at the tenth time. The erase density was 0.22, which means that the repetition was poor. When the cross section of the 10th sample was observed with a microscope, destruction of the anchor layer and elution of the support resin were observed.

[0039]

INDUSTRIAL APPLICABILITY A reversible thermosensitive recording layer is partially formed on the surface of a support, and a portion other than the recording layer is covered with a filling layer to protect the recording layer with the filling layer, or recording is carried out in a resin such as a support. By encapsulating the layers and the like, a reversible thermosensitive recording material having excellent processability can be obtained.

[Brief description of drawings]

FIG. 1 is an example in which a recording layer and a filling layer are present on the same surface on a support.

FIG. 2 shows a surface state of a medium contained in a resin of a transparent resin sheet.

FIG. 3 shows a state in which a recording layer and barrier layers above and below it are enclosed in a support and an oversheet.

[Explanation of symbols]

1 support 2 recording layers 3 protective layer 4 Packed bed 5 barrier layers 6 over sheet

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Claims (8)

[Claims] 1. A reversible thermosensitive recording medium having a reversible thermosensitive recording layer comprising a leuco dye and a reversible color developer on a support, wherein a filling layer is formed in a portion where the recording layer is not formed and the surface is flat. A reversible thermosensitive recording medium characterized in that 2. A reversible thermosensitive recording medium which partially has a reversible thermosensitive recording layer comprising a leuco dye and a reversible developer on a support made of a resin sheet, by applying heat and pressure to the recording medium, A reversible thermosensitive recording medium having a recording layer embedded in the support and having a flattened surface. 3. The reversible thermosensitive recording medium according to claim 2,
A reversible thermosensitive recording medium, characterized in that the melting point of the support resin is lower than that of the reversible color developer used for the recording layer, and the barrier layer is provided under the recording layer. 4. A reversible thermosensitive recording medium comprising an oversheet attached to the surface of the reversible heating recording medium according to claim 1 or 2. 5. A reversible thermosensitive recording medium in which a reversible thermosensitive recording layer consisting of a leuco dye and a reversible color developer is partially provided on a support made of a resin sheet, and an oversheet is laminated on the reversible thermosensitive recording layer. A reversible thermosensitive recording medium, characterized in that the recording layer is embedded in the support and / or the oversheet by applying heat and pressure to the surface and the surface is flattened. 6. The reversible thermosensitive recording medium according to claim 5,
The melting point of the support resin and / or the resin of the oversheet is lower than the melting point of the reversible developer used for the recording layer, and the surface of the sheet using the resin lower than the melting point of the reversible developer is the recording layer side. A reversible heating recording medium having a barrier layer. 7. A reversible thermosensitive recording medium, wherein the barrier layer according to claim 3 or 6 contains a resin having a melting point higher than that of the reversible developer. 8. A method of recording and erasing the reversible thermosensitive recording medium according to claim 4 or 5, using a laser.