JP2004203026A - Sheet material containing reversible multi-color recording layer, card, and recording method using them - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stick-on seat material which contains a reversible multi-color recording layer having clear coloring/decoloring and contrast to enable repetitive recording/clearing of information, and a card. <P>SOLUTION: The reversible multi-color recording layer 10 is formed by separating/laminating recording layers 11-13 containing a plurality of reversible thermal coloring compositions with various coloring tones. These reversible thermal coloring compositions provide the stick-on seat material 20 which should contain photothermal conversion material absorbing respective infrared with different wavelength band and heat-generating, and a card. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention relates to an adhesive sheet material and a card having a reversible multicolor recording layer capable of repeatedly recording information such as arbitrary images and characters, and a recording method using the same.

  In recent years, as an example of a display medium that replaces printed matter, a recording medium capable of recording and erasing information reversibly by heat, a so-called reversible thermosensitive recording medium, has been widely used in various prepaid cards, point cards, credit cards, IC cards, and the like. As a result, it has been put to practical use in visualization and readability of balances and other recorded information, and is also coming into practical use in copying machines and printers.

  Regarding the reversible thermosensitive recording medium as described above and a recording method using the same, various proposals have been made in the past (for example, see Patent Documents 1 to 4). These are the so-called low-molecular dispersion type, that is, a recording medium in which an organic low-molecular substance is dispersed in a resin base material, which changes the scattering of light by heat history and changes the recording layer to a cloudy or transparent state. For this reason, there is a disadvantage that the contrast between the image forming portion and the non-image forming portion is insufficient. Therefore, only a medium whose contrast is improved by providing a reflective layer under the recording layer has been put to practical use. I have.

  On the other hand, a leuco dye type, that is, a leuco dye that is an electron-donating color-forming compound in a resin base material, a recording medium having a recording layer in which a developer and a color reducing agent are dispersed, and a recording method using the same. The disclosure has been made (for example, see Patent Documents 5 to 9). In these, amphoteric compounds having an acidic group for developing a leuco dye and a basic group for decolorizing the developed leuco dye, a phenol compound having a long-chain alkyl, and the like are used as the developing / color-reducing agent. Since the recording medium and the recording method utilize the color development of the leuco dye itself, the recording medium and the recording method have good contrast and visibility as compared with the low molecular dispersion type, and have been widely used in recent years.

In the prior arts disclosed in the above-mentioned patent documents, only two kinds of colors, that is, the color of the material of the base material, that is, the color of the background, and the color discolored by heat can be expressed. However, in recent years, there has been an increasing demand for displaying multicolor images and recording various data in different colors in order to improve visibility and fashionability.
On the other hand, various recording methods for applying the above-described conventional method and displaying a multicolor image have been proposed.

  For example, a recording medium that performs multicolor display by visualizing or concealing layers and particles coated in multiple colors with a low-molecular dispersion type recording layer and a recording method using the same are disclosed ( See Patent Documents 10 to 12.) However, in the recording medium having such a configuration, the recording layer could not completely hide the color of the lower layer, and the color of the base material was transparent, and a high contrast could not be obtained.

  Other reversible thermosensitive multicolor recording media using leuco dyes have also been disclosed (for example, see Patent Documents 13 and 14), but these have a repeating unit having a different hue in the plane. For this reason, there is a problem that the recorded image can be obtained only in a very dark or faint image because the area ratio where each hue is actually recorded is small.

Further, there has been disclosed a reversible thermosensitive multicolor recording medium having a configuration in which recording layers using leuco dyes having different coloring temperatures, decoloring temperatures, cooling rates, etc. are separated and formed independently. References 15 to 23.).
However, there is a problem that it is difficult to control the temperature by a recording heat source such as a thermal head, and it is not possible to obtain a good contrast and to avoid color fogging. Further, it is very difficult to control the multicoloring of three or more colors only by the difference in the heating temperature and / or the cooling rate after heating with a thermal head or the like.

By the way, recently, various personal devices, such as a mobile phone or a digital camera, which have various kinds of so-called “dress-up panels” in which a part of the panel of the main body can be replaced are sold.
However, although there are many types of panels with various designs, it is only possible to use the ones prepared in advance. It was impossible to change at any time.

  In various devices such as VHS and 8 mm video, and various media such as MD, CD-RW, DVD-RW, DVD + RW, and DVD-RAM, music, video, data, etc. can be rewritten, but these devices and media, etc. If the desired content information, title, etc. are printed on, for example, a part of a device or a case of a medium, according to the recording information, they cannot be rewritten. Must be re-labeled or replaced.

When replacing the label seal, there is a problem that the remainder of the label seal may adhere to the disk surface, damage the disk surface during work, and also complicate the work and spoil the appearance. In particular, a printing method suitable for rewritable media has been desired.
Incidentally, assuming a configuration in which a reversible thermosensitive recording layer for performing recording using a conventionally known thermal head as described above is provided on the surface of the above-described device or media, rewriting is performed using a conventionally known thermal printer. Therefore, it has a problem that it is unsuitable especially for precision equipment.

  Further, in recent years, various kinds of cards such as various prepaid cards, point cards, credit cards, IC cards, authentication cards, and personal certificates have been widely used in a wide variety of applications. There is a great demand for making it possible to repeatedly record and delete characters, symbols, and the like, such as images, titles, and various types of content information.

JP-A-54-119377 JP-A-55-154198 JP-A-63-39377 JP-A-63-41186 JP-A-2-188293 JP-A-2-188294 JP-A-5-124360 JP-A-7-108761 JP-A-7-179043 JP-A-5-62189 JP-A-8-80682 JP-A-2000-198275 JP-A-8-58245 JP-A-2000-25338 JP-A-6-305247 JP-A-6-328844 JP-A-6-79970 JP-A-8-164669 JP-A-8-300825 JP-A-9-52445 JP-A-11-138997 JP 2001-162941 A JP-A-2002-59654

  As described above, a device having a complicated shape, various portable devices, other precision devices, various rewritable media or the like, or a card-type medium can store desired images, titles, various content information, and the like. There is a great demand for clear and multicolored characters and symbols that can be repeatedly recorded and erased, but there is no practically satisfactory one at present.

  Therefore, in the present invention, in view of such problems of the prior art, it has stable coloring and erasing, has contrast, and has stability and convenience without any practical problems in daily life, and furthermore, has a complicated With a reversible recording layer capable of high-speed recording / erasing on devices having various shapes, various portable devices, other precision devices, various media on which information is already recorded, and card-type media. An additional sheet material, a card, and a recording method using the same are provided.

  In the present invention, a recording layer containing a plurality of reversible thermosensitive coloring compositions having different coloring tones is formed by separating and laminating on one main surface of a support, and an adhesive layer forming surface is formed on the other main surface. The reversible thermosensitive coloring composition contains a light-to-heat conversion material that absorbs infrared rays in different wavelength ranges and generates heat, and has a reversible multicolor recording layer. Provide an attached sheet material.

  In the recording method of the present invention, a recording layer containing a plurality of reversible thermosensitive coloring compositions having different coloring tones is formed on one main surface of a support, separated and laminated, and the other main surface is adhered. The reversible thermosensitive color-forming composition is formed as a layer forming surface, and has a reversible multicolor recording layer, which contains a light-heat conversion material that absorbs infrared rays in different wavelength ranges and generates heat. Using the adhesive sheet material, first, the entire recording layer is subjected to a heat treatment so that the entire recording layer is in a decolorized state in advance, and then, exposure is performed by irradiating infrared rays in a selected wavelength region according to desired image information. Then, the image information is recorded by causing the recording layer to generate heat and selectively coloring.

  Further, in another recording method according to the present invention, a recording layer containing a plurality of reversible thermosensitive coloring compositions having different coloring color tones is formed on one main surface of the support by separating and laminating. The main surface is a surface for forming an adhesive layer, and the reversible thermosensitive color-forming composition contains a light-to-heat conversion material that absorbs infrared rays in different wavelength ranges and generates heat. Using the adhesive sheet material having the recording layer, first, the entire recording layer is subjected to a heat treatment so as to be in a colored state in advance, and then, according to desired image information, is irradiated with infrared rays in a selected wavelength region. By exposing the recording layer to heat to cause the recording layer to generate heat and selectively decoloring the image, thereby recording image information.

  Further, in the present invention, a recording layer containing a plurality of reversible thermosensitive coloring compositions having different color tone is formed on a supporting substrate, separated and laminated, and the reversible thermosensitive coloring compositions are different from each other. Provided is a card having a reversible multicolor recording layer, which contains a light-heat conversion material that generates heat by absorbing infrared rays in a wavelength range.

  Further, in the recording method of the present invention, a plurality of recording layers that reversibly develop a different color tone are formed on a supporting substrate in a separated and laminated manner, and at least the recording layers emit infrared rays in different wavelength ranges. A light-to-heat conversion material that absorbs and generates heat, a color-forming compound having an electron-donating property, and a developing / color-reducing agent having an electron-accepting property are contained. By using a card having a reversible multicolor recording layer that is reversibly changed into two states of coloring and decoloring by a reversible reaction between By leaving the entire recording layer in a decolored state, and then performing exposure by irradiating infrared rays in a selected wavelength region according to desired image information, causing the recording layer to generate heat and selectively coloring. , And image information is recorded.

  Further, in another recording method according to the present invention, a plurality of recording layers that reversibly develop colors different from each other are formed on a supporting substrate, separated and laminated, and the recording layers have at least different wavelength ranges. A light-to-heat conversion material that absorbs infrared rays to generate heat, a color-forming compound having an electron-donating property, and a developer / reducer having an electron-accepting property. First, by using a card having a reversible multicolor recording layer in which a recording layer is reversibly changed into two states of color development and decoloration by a reversible reaction with a color-reducing agent, heat treatment is performed. The entire recording layer is colored in advance and then exposed according to the desired image information by irradiating it with infrared rays in a selected wavelength range, causing the recording layer to generate heat and selectively decolorizing. By doing so, image information is recorded.

  According to the present invention, the reversible multicolor recording layer is selectively heated by irradiating infrared light of a selected wavelength, and the reversible color-developed state and the decolored state are converted.

  According to the present invention, by irradiating a recording medium with wavelength-selected infrared rays, an arbitrary recording layer can be selectively heated to perform reversible conversion between a color-developed state and a decolored state. As a result, an adhesive sheet material, a card, and a recording method using these, which can record and delete characters and symbols such as an arbitrary image, a title, and various kinds of content information, were obtained.

  According to the adhesive sheet material of the present invention, the other main surface of the support is provided with the surface on which the adhesive layer is provided. It can be pasted at any position such as a device of a type, can be replaced, and it is possible to improve the external appearance of various personal devices according to the user's individual preference, Various types of desired information can be added to the above-mentioned various types of personal devices and further rewritten, thereby improving the convenience in using them.

  Hereinafter, specific embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the following examples.

[First Embodiment]
First, the adhesive sheet material of the present invention will be described.
As shown in FIG. 1, the adhesive sheet material 20 of the present invention has a reversible multicolor recording layer 10 containing a reversible thermosensitive coloring composition on one main surface side of a support 1. Is a surface 21 for forming an adhesive layer.

  The reversible multicolor recording layer 10 in this example is composed of a recording layer having a three-layer structure, and the first recording layer 11, the second recording layer 12, and the third recording layer 13 are each formed of a heat insulating layer 14 , 15 and a protective layer 16 is formed on the uppermost layer.

  The support 1 is a sheet material for holding each of the recording layers 11 to 13. Any known material may be used as long as the material has heat resistance to the extent that thermal deformation does not occur during recording and erasing. Can be used. For example, in addition to a polymer material such as polyester and hard vinyl chloride, a metal material such as stainless steel and a material such as paper can be appropriately selected.

In order to improve the visibility of recorded information, the support 1 is preferably formed of a material having a high reflectance to visible light having a white color or a metallic color.
In the case where the surface to be attached has a white color or a metallic color, it is preferable to use a highly transparent material.

  Further, when the adhesive sheet material of the present invention is applied to an object having a curved surface or a complicated shape such as various personal devices, the support 1 is made of a material having extensibility. It is desirable that On the other hand, when affixing on a flat surface such as a card or a disk, it is desirable that the material be a material having high in-plane dimensions.

  In addition, on the adhesive layer forming surface 21 of the support 1, an adhesive layer that can be adhered to other objects may be formed in advance, or a double-sided tape or an adhesive is applied at the time of use to give an adhesive property. It may be.

The first to third recording layers 11 to 13 are formed by using a reversible thermosensitive coloring composition capable of reversibly controlling a decolored state and a colored state, in which stable repeated recording is possible. .
The first to third recording layers 11 to 13 each contain a light-to-heat conversion material that absorbs infrared rays having different wavelengths (λ ₁ , λ ₂ , λ _{3 in} FIG. 1) and generates heat. And
These first to third recording layers 11 to 13 can be formed, for example, by applying a dispersion of a leuco dye and a developing / reducing agent in a resin base material.

  The first to third recording layers 11 to 13 are formed using a predetermined leuco dye selected according to a desired color to be developed. For example, if the first to third recording layers 11 to 13 emit three primary colors, a full-color image can be formed as a whole.

As the leuco dye which is a color-forming compound having an electron donating property, an existing dye for thermal paper can be used.
Examples of the developing / color-reducing agents having electron accepting properties include organic acids having a long-chain alkyl group which are conventionally used in these (JP-A-5-124360, JP-A-7-108761, JP-A-7-188294). JP-A-2001-105733, JP-A-2001-113829, etc.) can be applied.

It is assumed that the first to third recording layers 11 to 13 each contain an infrared absorbing dye having an absorption in a different wavelength range. In the reversible multicolor recording layer 10 of FIG. 11 an infrared ray having a wavelength lambda _1, the second recording layer 12 is a wavelength lambda ₂ infrared, optical third recording layer 13 generates heat by absorbing the respective infrared rays of wavelength lambda ₃ - containing thermal conversion material It is assumed that

  The light-to-heat conversion material contained in the first to third recording layers 11 to 13 may be a phthalocyanine dye or a cyanine dye generally used as an infrared absorbing dye having little absorption in the visible wavelength range. Dyes, metal complex dyes, diimmonium dyes and the like can be applied. Furthermore, in order to generate heat only from an arbitrary light-to-heat conversion material, it is desirable to select a combination of materials whose wavelength-absorption bands of the light-to-heat conversion material are narrow and whose absorption bands do not overlap each other.

  Examples of the resin for forming the first to third recording layers 11 to 13 include polyvinyl chloride, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, ethyl cellulose, polystyrene, styrene copolymer, phenoxy resin, and polyester. , Aromatic polyester, polyurethane, polycarbonate, polyacrylate, polymethacrylate, acrylic copolymer, maleic polymer, polyvinyl alcohol, modified polyvinyl alcohol, hydroxyethyl cellulose, carboxymethyl cellulose, starch, and the like. . If necessary, various additives such as an ultraviolet absorber may be used in combination with these resins.

  The first to third recording layers 11 to 13 were prepared by dissolving or dispersing the leuco dye, the developer / decolorizer, the light-to-heat conversion material, and various additives in the resin using a predetermined solvent. The coating can be formed by applying a coating to each forming surface or by spraying with a spray or the like, and the method of forming the coating is not limited at all.

  The first to third recording layers 11 to 13 are preferably formed to have a thickness of about 1 to 20 μm, and more preferably to about 2 to 10 μm. If the film thickness is too small, a sufficient color density cannot be obtained, and if the film thickness is too large, the heat capacity of the recording layer becomes large, thereby deteriorating the color developing property and the decoloring property.

  Light-transmitting heat-insulating layers 14 and 15 are formed between the first recording layer 11 and the second recording layer 12 and between the second recording layer 12 and the third recording layer 13, respectively. It is desirable. Thereby, heat conduction from the adjacent recording layer is avoided, and so-called color fogging can be prevented.

  The heat insulating layers 14 and 15 can be formed using a conventionally known translucent polymer. For example, polyvinyl chloride, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, ethyl cellulose, polystyrene, styrene copolymer, phenoxy resin, polyester, aromatic polyester, polyurethane, polycarbonate, polyacrylate, polymethacrylic acid Examples include esters, acrylic acid-based copolymers, maleic acid-based polymers, polyvinyl alcohol, modified polyvinyl alcohol, hydroxyethyl cellulose, carboxymethyl cellulose, starch, and the like. Various additives such as an ultraviolet absorber may be used in combination with these polymers, if necessary.

  Further, the heat insulating layers 14 and 15 can also be formed using a light-transmitting inorganic film. For example, porous silica, alumina, titania, carbon, or a composite thereof is suitable because of its low thermal conductivity. In this case, the heat insulating layers 14 and 15 can be formed by a sol-gel method that can form a film from a liquid layer.

  The heat insulating layers 14 and 15 are desirably formed to have a thickness of about 3 to 100 μm, and more preferably about 5 to 50 μm. If the thicknesses of the heat insulating layers 14 and 15 are too thin, a sufficient heat insulating effect cannot be obtained. If the thickness is too thick, the thermal conductivity deteriorates when the entire recording layer is uniformly heated as described later, or the light transmitting property is deteriorated. This is because it is lowered.

  The protective layer 16 can be formed using a conventionally known ultraviolet curable resin or thermosetting resin, and the film thickness is desirably about 0.1 to 20 μm, and more preferably about 0.5 to 5 μm. If the thickness of the protective layer 16 is too small, a sufficient protective effect cannot be obtained, and if the thickness is too large, there is a disadvantage that heat transfer becomes difficult.

Next, the principle of performing multicolor recording on the reversible multicolor recording layer 10 constituting the adhesive sheet material 20 of the present invention shown in FIG. 1 will be described.
First, the first principle will be described.
The entire surface of the reversible multicolor recording layer 10 is heated at a temperature at which each recording layer is decolorized, for example, at a temperature of about 120 ° C., and the first to third recording layers 11 to 13 are decolorized in advance. . That is, in this state, it is assumed that the color of the support 1 is exposed.

Next, an arbitrary portion of the reversible multicolor recording layer 10 is irradiated with an infrared ray whose wavelength and output are arbitrarily selected by a semiconductor laser or the like.
For example, when the first recording layer 11 is to be colored, an infrared ray having a wavelength of λ ₁ is irradiated with energy at which the first recording layer 11 reaches a coloring temperature to cause the light-to-heat conversion material to generate heat and to produce color. A color-forming reaction is caused between the compound and the color-developing / color-reducing agent, and the irradiated portion is colored.

Similarly, the second recording layer 12 and the third recording layer 13 are also irradiated with infrared rays having wavelengths λ ₂ and λ ₃ , respectively, at an energy enough to reach a coloring temperature to cause each light-to-heat conversion material to generate heat. As a result, a color-forming reaction between the color-forming compound and the developing / color-reducing agent can be caused, and the irradiated portion can be colored.
By doing so, an arbitrary portion of the reversible recording layer 10 can be colored, and a full-color image can be formed.

  Further, in each of the recording layers colored as described above, an infrared ray having an arbitrary wavelength is further radiated at such an energy that the first to third recording layers 11 to 13 reach the decoloring temperature, and the light-heat By causing the conversion material to generate heat and causing a decoloring reaction between the color-forming compound and the color-developing / color-reducing agent, the color can be decolorized. By repeating this process, any image or character can be rewritten. Is possible.

Next, the second principle of multicolor recording will be described.
The entire surface of the reversible multicolor recording layer 10 is irradiated with infrared light at such an energy that each recording layer is colored, and the first to third recording layers 11 to 13 are all in a colored state in advance.

Next, an arbitrary portion of the reversible multicolor recording layer 10 is irradiated with an infrared ray whose wavelength and output are arbitrarily selected by a semiconductor laser or the like.
For example, when the first recording layer 11 is decolorized, the recording layer 11 is irradiated with infrared light having a wavelength λ ₁ at an energy enough to cause the first recording layer 11 to decolor, thereby causing the light-to-heat conversion material to generate heat. Is in the decolored state.
Similarly, the second recording layer 12 and the third recording layer 13 are also irradiated with infrared rays having wavelengths λ ₂ and λ ₃ at energy enough to reach the decoloring temperature, respectively, so that each light-heat conversion material is The irradiated portion can be decolored by generating heat. By doing so, any part of the reversible multicolor recording medium 10 can be erased, and a full-color image can be formed.

  Further, the recording layer decolored as described above is further irradiated with infrared rays having an arbitrary wavelength at an energy enough to reach the coloring temperature of the recording layers 11 to 13 so that light-heat conversion in a predetermined recording layer is performed. By causing the material to generate heat and causing a color-forming reaction between the color-forming compound and the color-developing / color-reducing agent, a desired color can be formed. By repeating this operation, images and titles can be rewritten. It is.

Which of the above recording methods is applied to the reversible multicolor recording layer 10 constituting the adhesive sheet material 20 of the present invention depends on the characteristics of each recording layer, the performance of the recording light source, and the like. Select as appropriate.
For example, the recording layer may be formed as a so-called positive layer in which the recording layer is colored at a high temperature and decolored at a temperature lower than that, or a so-called negative layer which is decolorized at a higher temperature and colored at a temperature lower than that. (For example, Japanese Patent Application Laid-Open No. H8-197853).

[Second embodiment]
Next, a preferred embodiment of the card of the present invention will be described.
As an example of the configuration of the card 30 according to the present invention, as shown in FIG. 2, a reversible multicolor recording layer 10 containing a reversible thermosensitive coloring composition is formed on one main surface side of a support substrate 31. What is.
The reversible multicolor recording layer 10 is composed of recording layers 11 to 13 having a three-layer structure, and the first recording layer 11, the second recording layer 12, and the third recording layer 13 are each formed of a heat insulating layer 14 , 15 and a protective layer 16 is formed on the uppermost layer.

  The card according to the present invention is not limited to the configuration shown in FIG. 2. For example, as shown in FIG. 3, the adhesive layer forming surface 21 of the adhesive sheet material 20 shown in FIG. 22 may be formed, and the support substrate 31 may be bonded through this.

The support substrate 31 has a function of holding the recording layers 11 to 13, and a conventionally known material may be appropriately used as long as the material has heat resistance to the extent that thermal deformation does not occur during recording and erasing. Can be. For example, polyesters such as polyethylene terephthalate (PET) resin, polymer materials such as hard vinyl chloride, metal materials such as stainless steel, various materials such as paper, paper coated with polyethylene resin and the like can be mentioned.
The thickness of the support substrate 31 is appropriately selected depending on the intended use of the card type recording medium. For example, when applied to various cards such as a credit card, an IC card, an authentication card, an authentication card, a personal certificate, etc., it can be selected to be, for example, about several hundred μm, and a general point card, prepaid card, etc. For example, a slightly thinner substrate can be selected.
Further, the support substrate 31 may be provided with a predetermined information recording function by providing a predetermined magnetic recording unit, an optical recording unit, an IC chip or the like.

The support substrate 1 is preferably formed of a material having a high reflectance to visible light having a white color or a metallic color in order to improve the visibility of recorded information.
In addition, in the configuration shown in FIG. 3, when the surface of the support substrate 31 is white, metallic, or provided with a design, the support 1 is preferably formed of a highly transparent material.

The first to third recording layers 11 to 13 are formed using a reversible thermosensitive coloring composition capable of reversibly controlling a decolored state and a colored state, which enables stable and repeated recording.
The first to third recording layers 11 to 13 each contain a light-to-heat conversion material that absorbs infrared rays having different wavelengths (λ ₁ , λ ₂ , λ _{3 in} FIG. 1) and generates heat. I do.
These first to third recording layers 11 to 13 can be formed, for example, by applying a dispersion of a leuco dye and a developing / reducing agent in a resin base material.

  The first to third recording layers 11 to 13 are formed using a predetermined leuco dye, which is selected according to a desired color to be developed. For example, the first to third recording layers 11 to 13 are formed. In 13, if the three primary colors are generated, a full-color image can be formed as a whole.

As the leuco dye which is a color-forming compound having an electron donating property, an existing dye for thermal paper can be used.
Examples of the developing / color-reducing agents having electron accepting properties include organic acids having a long-chain alkyl group which are conventionally used in these (JP-A-5-124360, JP-A-7-108761, JP-A-7-188294). JP-A-2001-105733, JP-A-2001-113829, etc.) can be applied.

It is assumed that the first to third recording layers 11 to 13 contain light-to-heat conversion materials having absorption in different wavelength ranges. For example, the first recording layer 11 is infrared wavelengths lambda _1, the light second recording layer 12 is an infrared ray having a wavelength lambda _2, the third recording layer 13 generates heat by absorbing the respective infrared rays of wavelength lambda ₃ -It shall contain a heat conversion material.

The light-to-heat conversion material contained in the first to third recording layers 11 to 13 is, for example, a phthalocyanine dye or a cyanine-based dye generally used as an infrared absorbing dye having little absorption in a visible wavelength region. Dyes, metal complex dyes, diimmonium dyes and the like can be applied.
Furthermore, in order to generate heat only from an arbitrary light-to-heat conversion material, it is desirable to select a combination of materials that have a narrow light absorption band and do not overlap each other.

  Examples of the resin for forming the first to third recording layers 11 to 13 include polyvinyl chloride, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, ethyl cellulose, polystyrene, styrene copolymer, phenoxy resin, and polyester. , Aromatic polyester, polyurethane, polycarbonate, polyacrylate, polymethacrylate, acrylic copolymer, maleic polymer, polyvinyl alcohol, modified polyvinyl alcohol, hydroxyethyl cellulose, carboxymethyl cellulose, starch, and the like. . If necessary, various additives such as an ultraviolet absorber may be used in combination with these resins.

  The first to third recording layers 11 to 13 are prepared by dissolving and dispersing the leuco dye, the developer / subtractor, the light-heat conversion material, and various additives in the resin using a predetermined solvent. It can be formed by applying the prepared paint to each forming surface.

  The first to third recording layers 11 to 13 are preferably formed to have a thickness of about 1 to 20 μm, and more preferably to about 2 to 10 μm. If the film thickness is less than 1 μm, a sufficient color density cannot be obtained, and if the film thickness exceeds 20 μm, the heat capacity of the recording layers 11 to 13 increases, the recording sensitivity decreases, and the color developability and decolorability deteriorate. I do.

  Light-transmitting heat-insulating layers 14 and 15 are formed between the first recording layer 11 and the second recording layer 12 and between the second recording layer 12 and the third recording layer 13, respectively. It is desirable. Thereby, heat conduction from the adjacent recording layer is avoided, and so-called color fogging can be prevented.

  The heat insulating layers 14 and 15 can be formed using a conventionally known translucent polymer. For example, polyvinyl chloride, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, ethyl cellulose, polystyrene, styrene copolymer, phenoxy resin, polyester, aromatic polyester, polyurethane, polycarbonate, polyacrylate, polymethacrylic acid Examples include esters, acrylic acid-based copolymers, maleic acid-based polymers, polyvinyl alcohol, modified polyvinyl alcohol, hydroxyethyl cellulose, carboxymethyl cellulose, starch, and the like. Various additives such as an ultraviolet absorber may be used in combination with these polymers, if necessary.

  Further, the heat insulating layers 14 and 15 can also be formed using a light-transmitting inorganic film. For example, it is preferable to use porous silica, alumina, titania, carbon, or a composite thereof, since the thermal conductivity is low and the heat insulating effect is high. In this case, the heat insulating layers 14 and 15 can be formed by a sol-gel method that can form a film from a liquid layer.

  The heat insulating layers 14 and 15 are desirably formed to have a thickness of about 3 to 100 μm, and more preferably about 5 to 50 μm. If the thicknesses of the heat insulating layers 14 and 15 are too thin, a sufficient heat insulating effect cannot be obtained. If the thickness is too large, the thermal conductivity deteriorates when the entire recording layer is uniformly heated in a recording method described later, Is to be reduced.

The protective layer 16 can be formed using a conventionally known ultraviolet curable resin or thermosetting resin, and the film thickness is desirably about 0.1 to 20 μm, and more preferably about 0.5 to 5 μm.
If the thickness of the protective layer 16 is less than 0.1 μm, a sufficient protective effect cannot be obtained. On the other hand, if the thickness exceeds 20 μm, there occurs a disadvantage that thermal conductivity is deteriorated.

Next, the principle of performing multicolor recording on the reversible multicolor recording layer 10 constituting the card 30 shown in FIGS. 2 and 3 will be described.
First, the first principle will be described.
The entire surface of the reversible multicolor recording layer 10 is heated to a temperature at which each recording layer can be erased, for example, at a temperature of about 120 ° C., and then cooled to erase the first to third recording layers 11 to 13 in advance. Leave in the color state. That is, in this state, it is assumed that the color of the support substrate 31 is exposed.

Next, an arbitrary portion of the reversible multicolor recording layer 10 is irradiated with infrared light whose wavelength and output are arbitrarily selected by a semiconductor laser or the like.
For example, when the first recording layer 11 is to be colored, an infrared ray having a wavelength of λ ₁ is irradiated with energy at which the first recording layer 11 reaches a coloring temperature to cause the light-to-heat conversion material to generate heat and to produce color. A color-forming reaction is caused between the compound and the color-developing / color-reducing agent, and the irradiated portion is colored.

Similarly, the second recording layer 12 and the third recording layer 13 are also irradiated with infrared rays having wavelengths λ ₂ and λ ₃ , respectively, at an energy enough to reach a coloring temperature to cause each light-to-heat conversion material to generate heat. As a result, a color-forming reaction between the color-forming compound and the developing / color-reducing agent can be caused, and the irradiated portion can be colored.
By doing so, an arbitrary portion of the reversible recording layer 10 can be colored, and a full-color image can be formed.

By the way, when recording the first recording layer 11 or the second recording layer 12, the transparency of the recording layer formed thereon has a great effect on the recording sensitivity of the lower recording layer.
That is, when the solubility of the developer and the color-reducing agent contained in the recording layer formed on the predetermined recording layer is poor in the polymer and the recording layer is dispersed and clouded, irradiation is performed. Since infrared rays are reflected and scattered by the upper layer, the recording sensitivity is significantly reduced. For this reason, it is important to use a solvent for forming the recording layer or a developing / reducing agent having high solubility in a polymer.

Further, the predetermined recording layer colored as described above is further irradiated with an infrared ray having an arbitrary wavelength at an energy enough to reach the decolorizing temperature of each of the recording layers 11 to 13 to generate heat from the light-heat conversion material. Then, the color can be decolorized by causing a decolorization reaction between the coloring compound and the developing / color-reducing agent, and by repeating this, any image or character can be rewritten. .
Further, the entirety of the reversible multicolor recording layer 10 partially colored as described above is uniformly heated at a temperature at which all the recording layers are erased, for example, 120 ° C. Information and images can be erased, and thereafter, the above operations can be repeated to record.

Next, the second principle of multicolor recording will be described.
The reversible multicolor recording layer 10 is entirely heated at a temperature at which each recording layer develops a color, for example, a high temperature of about 200 ° C., and then cooled, and the first to third recording layers 11 to 13 are all colored in advance. Leave it in a state.

Next, an arbitrary portion of the reversible multicolor recording layer 10 is irradiated with infrared light whose wavelength and output are arbitrarily selected by a semiconductor laser or the like.
For example, when the first recording layer 11 is decolorized, the recording layer 11 is irradiated with infrared light having a wavelength λ ₁ at an energy enough to cause the first recording layer 11 to decolor, thereby causing the light-to-heat conversion material to generate heat. Is in the decolored state.
Similarly, the second recording layer 12 and the third recording layer 13 are also irradiated with infrared rays having wavelengths λ ₂ and λ ₃ at energy enough to reach the decoloring temperature, respectively, so that each light-heat conversion material is The irradiated portion can be decolored by generating heat.
By doing as described above, an arbitrary portion of the reversible multicolor recording medium 10 can be erased, and a full-color image can be formed and various information can be recorded.

  The recording layers 11 to 13 which have been decolorized as described above are further irradiated with infrared rays having an arbitrary wavelength at an energy level at which the recording layers 11 to 13 reach the color development temperature, and the light-to-heat conversion material generates heat. By causing a color-forming reaction between the color-forming compound and the color-developing / color-reducing agent, an arbitrary portion of the recording layer can be colored.

  Further, the entirety of the reversible multicolor recording layer 10 partially decolored or colored as described above is uniformly heated at a temperature at which all the recording layers are colored, for example, 200 ° C. Then, the recording information and the image can be erased by cooling, and the recording can be repeated again by performing the above-described operation.

Which of the above-mentioned recording methods is applied to the reversible multicolor recording layer 10 constituting the card 30 of the present invention is appropriately determined according to the characteristics of each recording layer, the performance of the recording light source, and the like. select.
For example, the recording layer may be formed as a so-called positive layer in which the recording layer is colored at a high temperature and decolored at a temperature lower than that, or a so-called negative layer which is decolorized at a higher temperature and colored at a temperature lower than that. (For example, Japanese Patent Application Laid-Open No. H8-197853).

Next, specific examples of the present invention will be described.
First, the adhesive sheet material 20 having the reversible multicolor recording layer 10 will be described with reference to specific examples, but the present invention is not limited to the examples shown below.

[Example A1]
In this example, as shown in FIG. 1, a first recording layer 11, a heat insulating layer 14, a second recording layer 12, a heat insulating layer 15, a third recording layer 13, and a protective layer 16 are provided on a support 1. Are sequentially laminated, that is, a structure having a so-called three recording layers.

As the support 1, a translucent vinyl chloride resin material having a thickness of 100 μm and having extensibility was used.
As the first recording layer 11, the following composition is coated on the support 1 with a wire bar, and is heated and dried at 110 ° C. for 5 minutes to form a recording layer capable of developing yellow to a thickness of 4 μm. Formed. The absorbance of the first recording layer 11 at a wavelength of 915 nm was 1.0.

(Composition)
Leuco dye (fluoran compound: λmax = 490 nm): 1 part by weight, color-reducing agent (substance represented by the following formula (1)): 4 parts by weight

Vinyl chloride vinyl acetate copolymer: 10 parts by weight (vinyl chloride 90%, vinyl acetate 10%, average molecular weight (MW) 115000)
Cyanine infrared absorbing dye: 0.10 parts by weight (YKR-2081, manufactured by Yamamoto Kasei, absorption wavelength peak in recording layer: 910 nm)
Tetrahydrofuran (THF): 140 parts by weight

  On the first recording layer 11 formed as described above, a polyvinyl alcohol aqueous solution was applied and dried to form a heat insulating layer 14 having a thickness of 20 μm.

  On the heat insulating layer 14, the following composition was applied as a second recording layer 12 by a wire bar, and heated and dried at 110 ° C. for 5 minutes to form a layer capable of coloring cyan to a thickness of 6 μm. . The absorbance of the second recording layer 12 at a wavelength of 830 nm was 1.0.

(Composition)
Leuco dye: 1 part by weight (manufactured by Yamada Chemical Industries: H-3035 (substance represented by the following formula (2))

Developing / color reducing agent (substance represented by the following formula (3)): 4 parts by weight

Vinyl chloride vinyl acetate copolymer: 10 parts by weight (vinyl chloride 90%, vinyl acetate 10%, MW 115000)
Cyanine infrared absorbing dye: 0.08 parts by weight (YKR-2900, manufactured by Yamamoto Kasei, absorption wavelength peak in recording layer: 830 nm)
Tetrahydrofuran (THF): 140 parts by weight

  On the second recording layer 12 formed as described above, a polyvinyl alcohol aqueous solution was applied and dried to form a heat insulating layer 15 having a thickness of 20 μm.

  On the heat insulating layer 15, the following composition was applied as a third recording layer 13 by a wire bar, and was heated and dried at 110 ° C. for 5 minutes to form a layer capable of developing magenta to a thickness of 6 μm. . The absorbance of the third recording layer 13 at a wavelength of 785 nm was 1.0.

(Composition)
Leuco dye: 2 parts by weight (Hodogaya Chemical Co., Ltd .: Red DCF (substance represented by the following formula (4))

Developing / color reducing agent (substance represented by the following formula (5)): 4 parts by weight

Vinyl chloride vinyl acetate copolymer: 10 parts by weight (vinyl chloride 90%, vinyl acetate 10%, MW 115000)
Cyanine-based infrared absorbing dye: 0.08 parts by weight (CY-10, manufactured by Nippon Kayaku, absorption wavelength peak in recording layer: 790 nm)
Tetrahydrofuran (THF): 140 parts by weight

  On the third recording layer 13, a protective layer 16 having a thickness of about 2 μm was formed using an ultraviolet curable resin to obtain a reversible multicolor recording layer 10.

  The reversible multicolor recording layer 10 manufactured as described above is uniformly heated using a ceramics bar heated to 120 ° C., and the first, second, and third recording layers 11, 12, and 13 are decolorized. A sample in which the pasted sheet material 20 in the state was pasted on an MD medium, a DVD-RW medium, a mobile phone, a digital camera, or a portable MD player was used.

  An arbitrary position of the adhesive sheet material 20 in each of the above samples is irradiated with a semiconductor laser having a wavelength of 785 nm, 830 nm, or 915 nm, an output of 70 mW, and a spot diameter of 80 μm at a scan speed of 300 mm / s. When the operation was performed, clear and full-color images could be formed by controlling the laser power.

  Further, a semiconductor laser having a wavelength of 785 nm, 830 nm, or 915 nm, an output of 70 mW, and a spot diameter of 80 μm is irradiated on the portion where the recording was performed as described above under the conditions of a scan speed of 300 mm / s to perform the above-described recording. Was able to be erased. Further, when the erased portion was recorded under the above-mentioned writing conditions, an image was formed. As a result, it was confirmed that the adhesive sheet material of the present invention can be repeatedly recorded and erased.

[Example A2]
The above-described first recording layer 11, second recording layer 12, and third recording layer 13 are entirely heated using a ceramic bar heated to 180 ° C., and subsequently cooled, and all of them are previously colored. A sample in which the bonding sheet material 20 having the reversible multicolor recording layer 10 was mounted on an MD medium, a DVD-RW medium, a mobile phone, a digital camera, or a portable MD player was used as a sample.

Coloring is performed by irradiating a semiconductor laser having a wavelength of 785 nm, 830 nm, or 915 nm, an output of 70 mW, and a spot diameter of 80 μm to an arbitrary position of the adhesive sheet material 20 in each of the above samples at a scan speed of 300 mm / s. The part was deleted.
By controlling the power of each semiconductor laser, a high-definition and full-color image could be recorded. As a result, it was confirmed that the adhesive sheet material of the present invention can be repeatedly recorded and erased.

  As described above, a light-to-heat conversion material that absorbs infrared rays in different wavelength ranges and generates heat is uniformly dispersed in a reversible thermosensitive coloring composition having different coloring tones, and a reversible multicolor obtained by stacking a plurality of layers. The adhesive sheet material with the recording layer has stable coloring and erasing, high definition and contrast, and has practically no problematic image stability in everyday life, and can be printed and erased at high speed. .

  Next, preferred embodiments of the card 30 having the reversible multicolor recording layer 10 will be described with reference to specific examples, but the present invention is not limited to the following examples.

[Example B]
In this example, as shown in FIG. 2, a first recording layer 11, a heat insulating layer 14, a second recording layer 12, a heat insulating layer 15, a third recording layer 13, and a protective layer A card having a so-called three recording layers in which 16 are sequentially stacked is applied.

As the supporting substrate 31, a 100-μm-thick white polyethylene terephthalate substrate was used.
As the first recording layer 11, a coating containing the following composition is applied on the support substrate 1 with a wire bar, and is heated and dried at 110 ° C. for 5 minutes to form a recording layer capable of developing yellow. The film was formed to a thickness of 3 μm. The absorbance of the first recording layer 11 at a wavelength of 940 nm was 1.0.

(Composition)
Leuco dye (substance represented by the following formula (6)): 1 part by weight

Developing / color reducing agent (substance represented by the following formula (7)): 4 parts by weight

Vinyl chloride vinyl acetate copolymer: 10 parts by weight (vinyl chloride 90%, vinyl acetate 10%, average molecular weight (MW) 115000)
Cyanine-based infrared absorbing dye: 0.10 parts by weight (manufactured by HW SANDS, SDA7775, absorption wavelength peak in recording layer 933 nm)
Tetrahydrofuran (THF): 140 parts by weight

  On the first recording layer 11 formed as described above, a polyvinyl alcohol aqueous solution was applied and dried to form a heat insulating layer 14 having a thickness of 20 μm.

  On the heat insulating layer 14, the following composition was applied as a second recording layer 12 with a wire bar, and was heated and dried at 110 ° C. for 5 minutes to form a layer capable of developing cyan color to a thickness of 3 μm. . The absorbance of the second recording layer 12 at a wavelength of 860 nm was 1.0.

(Composition)
Leuco dye: 1.5 parts by weight (manufactured by Yamada Chemical Industries: H-3035 (substance represented by the following formula (8))

Developing / color reducing agent (substance represented by the following formula (9)): 4 parts by weight

Vinyl chloride vinyl acetate copolymer: 10 parts by weight (vinyl chloride 90%, vinyl acetate 10%, MW 115000)
Cyanine infrared absorbing dye: 0.08 parts by weight (manufactured by HW SANDS, SDA5688, absorption wavelength peak in recording layer 861 nm)
Tetrahydrofuran (THF): 140 parts by weight

  On the second recording layer 12 formed as described above, a polyvinyl alcohol aqueous solution was applied and dried to form a heat insulating layer 15 having a thickness of 20 μm.

  A coating containing the following composition is applied as a third recording layer 13 on the heat insulating layer 15 by a wire bar, and is heated and dried at 110 ° C. for 5 minutes to form a layer capable of developing magenta color. It was formed to a thickness of 3 μm. The absorbance of the third recording layer 13 at a wavelength of 800 nm was 1.0.

(Composition)
Leuco dye (substance represented by the following formula (10)): 1.7 parts by weight

Developing / color reducing agent (substance represented by the following formula (11)): 4 parts by weight

Vinyl chloride vinyl acetate copolymer: 10 parts by weight (vinyl chloride 90%, vinyl acetate 10%, MW 115000)
Cyanine infrared absorbing dye: 0.08 parts by weight (CY-10, manufactured by Nippon Kayaku, absorption wavelength peak 798 nm in recording layer)
Tetrahydrofuran (THF): 140 parts by weight

A protective layer 16 having a thickness of about 2 μm was formed on the third recording layer 13 using an ultraviolet curable resin, and a desired card 30 having the reversible multicolor recording layer 10 was obtained.
Then, the card 30 was uniformly heated using a ceramics bar heated to 120 ° C., and the first, second, and third recording layers 11, 12, and 13 were erased to obtain a sample card.

  An arbitrary position of the card 30 in each sample is irradiated with a semiconductor laser having an oscillation center wavelength of 800 nm, 860 nm, and 940 nm, an output of 400 mW, and a spot shape of 30 × 200 μm at a scan speed of 3.5 m / s. When an arbitrary recording operation was performed, a clear and full-color image could be formed by controlling the laser power.

In addition, the above recorded portion could be erased by uniformly heating the portion where the recording was performed as described above using a ceramics bar heated to 120 ° C. Further, when the erased portion was recorded under the above-mentioned writing conditions, an image was formed.
As a result, it was confirmed that the card of the present invention can be repeatedly recorded and erased.

  As described above, a light-to-heat conversion material that absorbs infrared rays in different wavelength ranges and generates heat is uniformly dispersed in a reversible thermosensitive coloring composition having different coloring tones, and a reversible multicolor obtained by stacking a plurality of layers. The card-shaped recording medium with a recording layer has stable coloring and erasing, high definition, contrast, and image stability that is practically acceptable in everyday life, and can be printed and erased at high speed. is there.

FIG. 1 shows a schematic cross-sectional view of an example of an adhesive sheet material having a reversible multicolor recording layer of the present invention. 1 shows a schematic cross-sectional view of an example of a card having a reversible multicolor recording layer of the present invention. FIG. 3 shows a schematic cross-sectional view of another example of a card having a reversible multicolor recording layer of the present invention.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 ... Support, 10 ... Reversible multicolor recording layer, 11 ... 1st recording layer, 12 ... 2nd recording layer, 13 ... 3rd recording layer, 14, 15 ... Heat insulation layer , 16: Protective layer, 20: Adhesive sheet material, 21: Adhesive layer forming surface, 22: Adhesive layer, 30: Card, 31: Support substrate

Claims (18)

On one main surface of the support, a recording layer containing a plurality of reversible thermosensitive color-forming compositions having different color tone is formed by separating and laminating, and the other main surface has a surface on which an adhesive layer is provided. Become
The reversible thermosensitive coloring composition contains a light-to-heat conversion material that absorbs infrared rays in different wavelength ranges to generate heat, and the adhesive sheet material has a reversible multicolor recording layer. .   The adhesive sheet material having a reversible multicolor recording layer according to claim 1, wherein the plurality of recording layers are formed by lamination with a heat insulating layer interposed therebetween.   The adhesive sheet material having a reversible multicolor recording layer according to claim 1, wherein a protective layer is formed on the outermost surface of the reversible multicolor recording layer.   The adhesive sheet material having a reversible multicolor recording layer according to claim 1, wherein the support is made of a material having a high reflectance with white or metallic luster.   The adhesive sheet material having a reversible multicolor recording layer according to claim 1, wherein the support is transparent or translucent to visible light.   The reversible multicolor recording layer according to claim 1, wherein an adhesive layer is formed on a main surface opposite to the reversible multicolor recording layer formed on the support. Adhesive sheet material having. The recording layer contains a coloring compound having an electron donating property, and a developer and a color reducing agent having an electron accepting property,
The recording layer is reversibly changed to two states of coloring and decoloring by a reversible reaction between the coloring compound and the developing / color reducing agent. 2. An adhesive sheet material having the reversible multicolor recording layer according to 1. On one main surface of the support, a recording layer containing a plurality of reversible thermosensitive color-forming compositions having different color tone is formed by separating and laminating, and the other main surface has a surface on which an adhesive layer is provided. The reversible thermosensitive coloring composition contains a light-to-heat conversion material that absorbs infrared rays in different wavelength ranges and generates heat, using an adhesive sheet material having a reversible multicolor recording layer. ,
Applying a heat treatment, the entire recording layer is previously in a decolored state,
Exposure is performed by irradiating infrared rays in a wavelength region selected according to desired image information,
The recording method according to claim 1, wherein the image information is recorded by causing the recording layer to generate heat and selectively forming a color. On one main surface of the support, a recording layer containing a plurality of reversible thermosensitive color-forming compositions having different color tone is formed by separating and laminating, and the other main surface has a surface on which an adhesive layer is provided. The reversible thermosensitive coloring composition contains a light-to-heat conversion material that absorbs infrared rays in different wavelength ranges and generates heat, using an adhesive sheet material having a reversible multicolor recording layer. ,
By performing a heat treatment, the entire recording layer is brought into a colored state in advance,
Exposure is performed by irradiating infrared rays in a wavelength region selected according to desired image information,
A recording method for recording the image information by causing the recording layer to generate heat and selectively decoloring the recording layer. On the support substrate, a recording layer containing a plurality of reversible thermosensitive coloring compositions having different coloring colors is formed by separating and laminating,
A card having a reversible multicolor recording layer, wherein the reversible thermosensitive coloring composition contains a light-to-heat conversion material that absorbs infrared rays in different wavelength ranges and generates heat. On one main surface of the support, a recording layer containing a plurality of reversible thermosensitive coloring compositions having different coloring tones is formed by separation and lamination,
The reversible thermosensitive coloring composition contains a light-to-heat conversion material that absorbs infrared rays in different wavelength ranges and generates heat.
The reversible multicolor recording layer according to claim 10, wherein an adhesive layer is provided on another main surface of the support, and the support substrate is attached to the support via the adhesive layer. card. The recording layer contains a coloring compound having an electron donating property, and a developer and a color reducing agent having an electron accepting property,
The recording layer is reversibly changed to two states of coloring and decoloring by a reversible reaction between the coloring compound and the developing / color reducing agent. A card having the reversible multicolor recording layer according to claim 10.   The card having a reversible multicolor recording layer according to claim 10, wherein the plurality of recording layers are formed by lamination with a heat insulating layer interposed therebetween.   The card having a reversible multicolor recording layer according to claim 10, wherein a protective layer is formed on the outermost surface of the reversible multicolor recording layer.   The card having a reversible multicolor recording layer according to claim 10, wherein the support substrate is made of a material having a high reflectance with white or metallic luster.   The card having a reversible multicolor recording layer according to claim 11, wherein the support is transparent or translucent to visible light. A plurality of recording layers that reversibly develop different colors are formed on a supporting substrate, and are separated and laminated. The recording layer has at least a light-to-heat converter that absorbs infrared rays in different wavelength ranges and generates heat. The material, a color developing compound having an electron donating property, and a developing / reducing agent having an electron accepting property are contained, and the color forming compound and the reversible reaction between the developing and the color reducing agent are included. Using a card having a reversible multicolor recording layer that is adapted to reversibly change the recording layer to two states of color development and decoloration,
Applying a heat treatment, the entire recording layer is previously in a decolored state,
Exposure is performed by irradiating infrared rays in a wavelength region selected according to desired image information,
The recording method according to claim 1, wherein the image information is recorded by causing the recording layer to generate heat and selectively forming a color. A plurality of recording layers that reversibly develop different colors are formed on a supporting substrate, and are separated and laminated. The recording layer has at least a light-to-heat converter that absorbs infrared rays in different wavelength ranges and generates heat. The material, a color developing compound having an electron donating property, and a developing / reducing agent having an electron accepting property are contained, and the color forming compound and the reversible reaction between the developing and the color reducing agent are included. Using a card having a reversible multicolor recording layer that is adapted to reversibly change the recording layer to two states of color development and decoloration,
By performing a heat treatment, the entire recording layer is brought into a colored state in advance,
Exposure is performed by irradiating infrared rays in a wavelength region selected according to desired image information,
The recording method according to claim 1, wherein the image information is recorded by causing the recording layer to generate heat and selectively forming a color.

Images