JP4382541B2 - Reversible thermosensitive recording medium, reversible thermosensitive recording label, reversible thermosensitive recording member, image processing apparatus and image processing method - Google Patents

Description

  The present invention has good color density and excellent high-speed erasability, and also exhibits good high-speed erasability in a wide environmental range from normal temperature and normal humidity to low temperature and low humidity, and can perform rewrite recording with high practicality. The present invention relates to a reversible thermosensitive recording medium, a reversible thermosensitive recording label using the reversible thermosensitive recording medium, a reversible thermosensitive recording member, an image processing apparatus, and an image processing method.

  In recent years, a reversible thermosensitive recording medium that can form a temporary image and can erase the image when it is no longer needed attracts attention. A typical example is a developer such as an organic phosphate compound, aliphatic carboxylic acid compound or phenol compound having a long-chain aliphatic hydrocarbon group in the resin, and a color former such as a leuco dye. A reversible thermosensitive recording medium dispersed is known.

  For example, Patent Documents 1 and 2 propose reversible thermochromic compositions using a phenol compound as an electron accepting compound. The proposed reversible thermochromic composition has high contrast between color development and decoloration, and can be erased at high speed, and can be erased by heating with a thermal head in a normal temperature and humidity environment. Have However, in this case, there is a problem that the erasability in a low temperature and low humidity environment deteriorates and the erasure becomes insufficient.

  Patent Document 3 proposes a reversible thermosensitive recording material using one or more adducts of ethylene oxide, propylene oxide, and butylene oxide as a decoloring agent. However, in this proposal, the numerical range of the average molecular weight is not specified, and the material used in the examples is an adduct of polyethylene oxide (polyethylene glycol) having an average molecular weight of less than 2,000, and is used in a low temperature and low humidity environment. There is no disclosure or suggestion about improving erasability.

  Patent Document 4 proposes a reversible thermosensitive recording material using a compound having a polyoxyethylene chain in the molecule as a decoloring aid. However, this proposal includes a developer / subtractor as an essential requirement. It has a mechanism of color development that releases hydrogen ions during high-temperature heating to cause color development and acts as a base during low-temperature heating to erase. It does not employ a mechanism of color development / decoloration that forms a relatively colored state and a decolored state due to the difference in the heating temperature with the colorant and the cooling rate after heating. Further, there is no description about the number average molecular weight of the compound having a polyoxyethylene chain in the molecule, and there is no disclosure or suggestion that the erasability is improved in a low temperature and low humidity environment.

  Therefore, the color density is good, the high-speed erasability is excellent, and the high-speed erasability is exhibited in a wide range of environments from normal temperature to normal humidity to low temperature and low humidity. The present situation is that a heat-sensitive recording medium has not been obtained yet, and its prompt provision is desired.

JP-A-10-67177 JP-A-10-119440 JP-A-8-108627 JP-A-8-85255 (Patent No. 3075101)

  This invention is made | formed in view of this present condition, and makes it a subject to solve the said various problems in the past and to achieve the following objectives. That is, the present invention has a good color density and excellent high-speed erasability, and also exhibits good high-speed erasability in a wide range of environments from normal temperature and normal humidity to low temperature and low humidity, and performs highly practical rewrite recording. It is an object to provide a reversible thermosensitive recording medium, a reversible thermosensitive recording label, a reversible thermosensitive recording member, an image processing apparatus, and an image processing method using the reversible thermosensitive recording medium.

  As a result of intensive studies by the present inventors in order to solve the above problems, the following knowledge has been obtained. That is, as a result of intensive studies on the dependency of erasability on reversible thermosensitive recording medium on temperature and humidity, when a polyalkylene glycol compound having a plurality of ether groups in the molecule is added, high-speed erasability is not dependent on temperature and humidity. It was found that by using a compound having a number average molecular weight of 2,000 or more, high-speed erasure by a thermal head is possible, and furthermore, the erasing characteristics are good without being affected by temperature and humidity.

The present invention is based on the above findings of the present inventors, and means for solving the above problems are as follows. That is,
<1> A support and at least a heat-sensitive layer whose color tone reversibly changes depending on temperature on the support, and the heat-sensitive layer has a number average molecular weight of 6,000 to 6,000,000. A reversible thermosensitive recording medium comprising a polyalkylene glycol compound, wherein the thermosensitive layer contains an electron donating color forming compound and an electron accepting compound.
<2> The reversible thermosensitive recording medium according to <1>, wherein the polyalkylene glycol compound has a number average molecular weight of 15,000 to 6,000,000.
<3> The reversible thermosensitive recording medium according to any one of <1> to <2>, wherein the polyalkylene glycol compound is a polyethylene glycol compound.
<4> The reversible thermosensitive recording medium according to any one of <1> to <3>, wherein one end of the polyalkylene glycol compound is substituted with any of an ether group, an ester group, and a urethane group.
<5> The reversible thermosensitive recording according to any one of <1> to <4>, wherein the content of the polyalkylene glycol compound in the thermosensitive layer is 0.1 to 50 parts by mass with respect to 100 parts by mass of the resin component. It is a medium.
<6> The reversible thermosensitive recording medium according to any one of <1> to <5>, wherein the electron-accepting compound is a phenol compound represented by the following general formula (1).
However, in said general formula (1), n represents the integer of 1-3. X represents a divalent group containing a nitrogen atom or an oxygen atom. R ¹ and ^{R 2,} to display the aliphatic hydrocarbon group.
<7> The reversible thermosensitive recording medium according to <6>, wherein X in the general formula (1) is a urea group.
<8> The above <1> to <7>, wherein the heat-sensitive layer contains a decolorization accelerator, and the decolorization accelerator is a compound having at least one of an amide group, a urethane group, and a urea group in the molecule. The reversible thermosensitive recording medium according to any one of the above.
<9> The reversible thermosensitive recording medium according to any one of <1> to <8>, wherein the thermosensitive layer contains a resin in a crosslinked state.
<10> The reversible thermosensitive recording medium according to any one of <1> to <9>, wherein the reversible thermosensitive recording medium is processed into any one of a card shape, a label shape, and a sheet shape.
<11> The reversible thermosensitive recording medium according to any one of <1> to <10>, wherein the adhesive layer or the pressure-sensitive adhesive layer is provided on a surface opposite to a surface on which an image is formed. And a reversible thermosensitive recording label.
<12> A reversible thermosensitive recording comprising an information storage unit and a reversible display unit, wherein the reversible display unit includes the reversible thermosensitive recording medium according to any one of <1> to <10>. It is a member.
<13> The reversible thermosensitive recording member according to <12>, wherein the information storage unit and the reversible display unit are integrated.
<14> The information recording unit according to any one of <12> to <13>, wherein the information recording unit is selected from a magnetic thermosensitive layer, a magnetic stripe, an IC memory, an optical memory, an RF-ID tag card, a disk, a disk cartridge, and a tape cassette. This is a reversible thermosensitive recording member .
<15> Heating the reversible thermosensitive recording medium to form an image on the reversible thermosensitive recording medium, and heating the reversible thermosensitive recording medium to erase the image formed on the reversible thermosensitive recording medium. An image processing method comprising the reversible thermosensitive recording medium according to any one of <1> to <10>, wherein the reversible thermosensitive recording medium includes at least one of the above.
<16> The image processing method according to <15> , wherein the image formation is performed using any one of a thermal head and a laser irradiation apparatus.
<17> the images are erased, the thermal head, a ceramic heater, a heat roll, wherein a hot stamp, a is performed using any one selected from the heat block and laser irradiation apparatus from <15> to any one of <16> This is an image processing method.
<18> The image processing method according to any one of <15> to <17> , wherein a new image is formed while erasing the image using a thermal head.

  The reversible thermosensitive recording medium of the present invention has at least a support and a thermosensitive layer whose color tone reversibly changes depending on temperature on the support, and the thermosensitive layer has a number average molecular weight of 2,000. It contains the above polyalkylene glycol compounds (excluding polypropylene glycol compounds having a number average molecular weight of 5,000 or less). In the reversible thermosensitive recording medium of the present invention, the thermosensitive layer contains a polyalkylene glycol compound having a number average molecular weight of 2,000 or more, whereby a plurality of unpaired pairs of ether groups in the polyalkylene glycol compound. However, it is considered that the developer interacts with the hydrogen bonding group of the developer, and the layer separation of the developer and the color former is likely to occur even at low energy, thereby promoting the crystallization of the developer. As a result, the color density is good, the high-speed erasability is excellent, and good high-speed erasability is exhibited in a wide range of environments from normal temperature to normal humidity to low temperature and low humidity, so that practical rewriting recording can be performed. .

  The reversible thermosensitive recording label of the present invention has either an adhesive layer or a pressure-sensitive adhesive layer on the surface opposite to the image forming surface of the reversible thermosensitive recording medium of the present invention. In the reversible thermosensitive recording label, in the reversible thermosensitive recording medium portion, the thermosensitive layer contains a polyalkylene glycol compound having a number average molecular weight of 2,000 or more, so that it can be used in a wide environmental range from normal temperature and normal humidity to low temperature and low humidity. An image having good high-speed erasability and excellent visibility and the like is formed. Moreover, since it has any one of the adhesive layer and the pressure-sensitive adhesive layer, it is difficult to directly apply the heat-sensitive layer, a thick substrate such as a card made of vinyl chloride with a magnetic stripe, a container having a sheet size larger than the card size , Stickers, large screens, etc.

  The reversible thermosensitive recording member of the present invention has an information storage unit and a reversible display unit, and the reversible display unit is the reversible thermosensitive recording medium of the present invention. In the reversible thermosensitive recording member, in the reversible display portion, the thermosensitive layer contains a polyalkylene glycol compound having a number average molecular weight of 2,000 or more, so that a high speed is obtained in a wide environmental range from normal temperature and normal humidity to low temperature and low humidity. It exhibits erasability, and a desired image is formed and erased at a desired timing. And an image excellent in contrast, visibility, etc. is formed. On the other hand, in the information recording unit, character information, image information, music, etc. are recorded by a recording method according to the type of magnetic thermosensitive layer, magnetic stripe, IC memory, optical memory, RF-ID tag card, disk, disk cartridge, tape cassette, etc. Desired information such as information and video information is recorded and erased.

  The image processing apparatus of the present invention includes at least one of an image forming unit for heating the reversible thermosensitive recording medium of the present invention to form an image and an image erasing unit for erasing the image. In the image processing apparatus, the image erasing unit heats the reversible thermosensitive recording medium of the present invention to form an image on the reversible thermosensitive recording medium. On the other hand, the image forming means erases the image formed on the reversible thermosensitive recording medium by heating the reversible thermosensitive recording medium of the present invention. In the present invention, as the reversible thermosensitive recording medium, the reversible thermosensitive recording medium of the present invention having good high-speed erasability in a wide environmental range from room temperature and normal humidity to low temperature and low humidity is used. Highly practical rewrite recording can be performed.

  In the image processing method of the present invention, the reversible thermosensitive recording medium of the present invention is heated to perform at least one of image formation and image erasure. In the image processing method, the reversible thermosensitive recording medium of the present invention is heated to form an image on the reversible thermosensitive recording medium. On the other hand, the reversible thermosensitive recording medium of the present invention is heated to erase the image formed on the reversible thermosensitive recording medium. In the present invention, as the reversible thermosensitive recording medium, the reversible thermosensitive recording medium of the present invention having good high-speed erasability in a wide environmental range from room temperature and normal humidity to low temperature and low humidity is used. Highly practical rewrite recording can be performed.

  According to the present invention, the conventional problems can be solved, the color density is good, the high-speed erasability is excellent, and good high-speed erasability is exhibited in a wide environmental range from normal temperature and normal humidity to low temperature and low humidity. Highly rewritable recording can be performed.

(Reversible thermosensitive recording medium)
The reversible thermosensitive recording medium of the present invention comprises at least a support and a thermosensitive layer, and further comprises an intermediate layer, a protective layer, a back layer, and other layers as required.

<Support>
The support is not particularly limited in its shape, structure, size and the like, and can be appropriately selected according to the purpose. Examples of the shape include a flat plate shape, May be a single layer structure or a laminated structure, and the size can be appropriately selected according to the size of the reversible thermosensitive recording medium.

Examples of the material for the support include inorganic materials and organic materials. Examples of the inorganic material include glass, quartz, silicon, silicon oxide, aluminum oxide, SiO ₂ and metal. Examples of the organic material include paper, cellulose derivatives such as cellulose triacetate, synthetic paper, polyethylene terephthalate, polycarbonate, polystyrene, and polymethyl methacrylate. These may be used individually by 1 type and may use 2 or more types together.

The support is preferably surface-modified by corona discharge treatment, oxidation reaction treatment (chromic acid, etc.), etching treatment, easy adhesion treatment, antistatic treatment, etc. for the purpose of improving the adhesion of the coating layer. . Moreover, it is preferable to add a white pigment such as titanium oxide to the support to make it white.
There is no restriction | limiting in particular as thickness of the said support body, According to the objective, it can select suitably, 50-2,000 micrometers is preferable and 100-1,000 micrometers is more preferable.

  The support may have a magnetic heat-sensitive layer on the same surface as the heat-sensitive layer and / or on the opposite surface. The reversible thermosensitive recording medium of the present invention may be attached to another medium via an adhesive layer or the like. Alternatively, a back coat layer is provided on one side of a support such as a PET film, the release layer used for the thermal transfer ribbon on the opposite side of the back coat layer, the heat-sensitive layer of the present invention on the release layer, and paper or resin on the surface. A resin layer that can be transferred to a film, a PET film, or the like may be provided and transferred using a thermal transfer printer.

<Thermosensitive layer>
The heat-sensitive layer reversibly changes its color tone depending on temperature, and includes at least a polyalkylene glycol compound, an electron-donating color-forming compound and an electron-accepting compound, a decoloring accelerator, a binder resin, and further necessary Depending on the, other ingredients are included.

  “The color tone reversibly changes depending on temperature” in the heat-sensitive layer means a phenomenon in which a visible change is reversibly caused by a temperature change, and is relative to the difference in heating temperature and cooling rate after heating. This means that a colored state and a decolored state can be formed. In this case, the visible change can be divided into a change in color state and a change in shape, but in the present invention, a material that mainly causes a change in color state is used. The change in the color state includes changes in transmittance, reflectance, absorption wavelength, scattering degree, and the like, and an actual reversible thermosensitive recording material displays by a combination of these changes. More specifically, there is no particular limitation as long as the transparency and color tone are reversibly changed by heat, and it can be appropriately selected according to the purpose. For example, the first specific temperature higher than normal temperature is Examples thereof include a state of one color, which is heated at a second specific temperature higher than the first specific temperature and then cooled to be in a second color state. Among these, those in which the color state changes particularly at the first specific temperature and the second specific temperature are preferably used.

Examples of these are those that become transparent at the first specific temperature and become cloudy at the second specific temperature (Japanese Patent Laid-Open No. 55-154198), develop color at the second specific temperature, Those which are decolored at a specific temperature (JP-A-4-224996, JP-A-4-247985, JP-A-4-267190, etc.), become cloudy at the first specific temperature, and at the second specific temperature Those that become transparent (Japanese Patent Laid-Open No. 3-169590), those that develop black, red, blue, etc. at the first specific temperature and decolorize at the second specific temperature (Japanese Patent Laid-Open No. 2-188293, (Kaihei 2-188294).
Among these, in particular, a polyalkylene glycol compound, an electron-donating color-forming compound (hereinafter, sometimes referred to as “coloring agent”), and an electron-accepting compound (hereinafter, referred to as “developing agent”). ) Is preferred.

  As described above, the reversible thermosensitive recording medium of the present invention can form a relatively colored state and a decolored state depending on at least one of the heating temperature and the cooling rate after heating. The basic coloring / decoloring phenomenon of the composition comprising the color former and developer used in the present invention will be described. FIG. 1 shows the relationship between the color density and temperature of this reversible thermosensitive recording medium. When the temperature of the recording medium initially in the decolored state (A) is raised, color development occurs at the temperature T1 at which melting starts, and the molten color state (B) is obtained. When rapidly cooled from the melt color state (B), the color state can be lowered to room temperature and a solid color state (C) is obtained. Whether or not this color development state is obtained depends on the rate of temperature decrease from the molten state, and in slow cooling, the color disappears during the temperature decrease, and the same color disappearance state (A) or rapid color development state (C ) A relatively low concentration state is formed. On the other hand, when the temperature of the rapid color development state (C) is raised again, decoloration occurs at a temperature T2 lower than the color development temperature (D to E), and when the temperature is lowered from here, the same color disappearance state (A) is restored. The actual color developing temperature and color erasing temperature vary depending on the combination of the developer and color former used, and can be selected according to the purpose. Further, the density of the melt coloring state and the coloring density when rapidly cooled are not necessarily the same and may be different.

  In the reversible thermosensitive recording medium of the present invention, the colored state (C) obtained by quenching from the molten state is a state in which the developer and the color former are mixed in a state where they can be contacted with each other, and this is a solid state. Often forms a state. This state is a state where the developer and the color former are aggregated to maintain the color development, and it is considered that the color development is stabilized by the formation of this aggregated structure. On the other hand, the decolored state is a state in which both phases are separated. This state is a state in which molecules of at least one compound aggregate to form a domain or crystallize, and the color former and developer are separated and stabilized by aggregation or crystallization. It is done. In many cases, more complete color erasure occurs due to phase separation of the two and crystallization of the developer. In both the decolorization by slow cooling from the melted state shown in FIG. 1 and the decoloration by heating from the colored state, the aggregation structure changes at this temperature, and phase separation and crystallization of the developer occur.

  In the reversible thermosensitive recording medium of the present invention, color recording may be formed by heating to a temperature at which it is once melt mixed with a thermal head or the like and then rapidly cooling. Further, decolorization is two methods, a method of slowly cooling from a heated state and a method of heating to a temperature slightly lower than the coloring temperature. However, they are the same in the sense that they are phase-separated or at least temporarily held at a temperature at which one crystallizes. The reason for rapid cooling in the formation of the colored state is to prevent the temperature from being maintained at this phase separation temperature or crystallization temperature. The rapid cooling and slow cooling here are relative to one composition, and the boundary thereof changes depending on the combination of the color former and the developer.

-Polyalkylene glycol compound-
As the polyalkylene glycol compound, a polyalkylene glycol compound having a number average molecular weight of 2,000 or more (excluding a polypropylene glycol compound having a number average molecular weight of 5,000 or less) is used, and 2,000 to 6,000 is used. 6,000 is preferable, 6,000 to 6,000,000 is more preferable, and 15,000 to 6,000,000 is still more preferable.
When the number average molecular weight is less than 2,000 (less than 5,000 in the case of a polypropylene glycol compound), the erasability in a low-temperature and low-humidity environment may be insufficient, and when it exceeds 6,000,000. In some cases, the solubility in an organic solvent used at the time of coating the heat-sensitive layer is reduced, which may cause coating defects.
Here, the number average molecular weight of the polyalkylene glycol compound can be measured, for example, by gel permeation chromatography analysis (GPC).

Examples of the polyalkylene glycol compound include a polyethylene glycol compound, a polypropylene glycol compound (excluding a polypropylene glycol compound having a number average molecular weight of 5,000 or less), a polytetramethylene glycol compound, a polyhexamethylene glycol compound, and the like. Among these, a polyethylene glycol compound is particularly preferable.
The polyalkylene glycol compound includes a polyalkylene glycol having a number average molecular weight of 2,000 to 6,000,000 (in the case of a polypropylene glycol compound, the number average molecular weight is 5,000 to 6,000,000), Copolymers with other known polymer compounds can also be used.
These polyalkylene glycol compounds can be used alone or in combination.

In addition, as the polyalkylene glycol compound, from the viewpoint of interaction with a dye or a developer, an ether group, an ester group, and a urethane group are formed at one end represented by the following general formulas (1) to (3). It is preferred to use a polyalkylene glycol compound having a selected substituent.
_{RO (C m H 2m O)} n H ··· formula (1)
_{RCOO (C m H 2m O)} n H ··· formula (2)
_{RNHCOO (C m H 2m O)} n H ··· formula (3)

  In the general formulas (1) to (3), R represents an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, a heterocyclic group, or a silyl group, which may be further substituted with a substituent. . m and n represent an integer of 1 or more in a range where the number average molecular weight is 2,000 or more. However, when m is 3, n represents an integer of 1 or more in a range where the number average molecular weight is 5,000 or more.

  Examples of the polyalkylene glycol compound having a substituent selected from an ether group, an ester group, and a urethane group at one end represented by the general formulas (1) to (3) include, for example, polyethylene glycol monomethyl ether, polyethylene glycol Monoethyl ether, polyethylene glycol monooleyl ether, polyethylene glycol monolauryl ether, polyethylene glycol monostearyl ether, polyethylene glycol monoacetate, polyethylene glycol monolaurate, polyethylene glycol monostearate, polyethylene glycol monostearyl carbamate, polypropylene glycol monomethyl ether, Polypropylene glycol monostearate, polypropylene glycol monostearyl carbonate Bamate, polytetramethylene glycol monomethyl ether, polytetramethylene glycol monostearate, polytetramethylene glycol monostearyl carbamate, polyhexamethylene glycol monomethyl ether, polyhexamethylene glycol monostearate, polyoctamethylene glycol monomethyl ether, polyoctamethylene Glycol monostearate, polydecamethylene glycol monomethyl ether, polydecamethylene glycol monostearate, polydodecamethylene glycol monomethyl ether, polydodecamethylene glycol monostearate, polymethylene glycol monomethyl ether, polymethylene glycol monostearate, etc. Can be mentioned.

The addition amount of the polyalkylene glycol compound in the heat-sensitive layer varies depending on the compound to be used or a combination thereof, and cannot be specified unconditionally. However, 0.1 to 0.1 parts by mass of the resin component in the heat-sensitive layer. 50 mass parts is preferable and 1-50 mass parts is more preferable.
If the addition amount is less than 0.1 parts by mass, the erasability in a low temperature and low humidity environment may be reduced, and if it exceeds 50 parts by mass, the color density may be reduced.

-Electron-accepting compound-
The electron-accepting compound is not particularly limited as long as it can reversibly develop and decolorize by using heat as a factor. (1) Color development for developing an electron-donating color-forming compound (color former) Having a function (for example, phenolic hydroxyl group, carboxylic acid group, phosphoric acid group, etc.) and (2) a structure for controlling cohesion between molecules (for example, a structure in which long-chain hydrocarbon groups are linked). A compound having at least one structure in the molecule is preferred. The linking moiety may be connected to a divalent or higher valent linking group containing a hetero atom, and the long chain hydrocarbon group contains at least one of the same linking group and aromatic group. Also good. Among these, it is particularly preferable to use a phenol compound having an alkyl chain represented by the following general formula (1).

However, in said general formula (1), n represents the integer of 1-3. X represents a divalent group containing a nitrogen atom or an oxygen atom. R ¹ and R ² represent an aliphatic hydrocarbon group, which may be further substituted with a substituent.

In the general formula (1), R ² has 1 to 22 carbon atoms, and particularly preferably R ² has 8 to 18 carbon atoms. The X group is a divalent group containing a nitrogen atom or an oxygen atom, particularly preferably an amide group and a urea group, and more preferably a urea group. Further, R ¹ represents an aliphatic hydrocarbon group having 2 or more carbon atoms, and particularly preferably an aliphatic hydrocarbon group having 5 or more carbon atoms.

In the general formula (1), the aliphatic hydrocarbon group may be linear or branched and may have an unsaturated bond. Examples of the substituent bonded to the hydrocarbon group include a hydroxyl group, a halogen atom, and an alkoxy group. When the sum of the carbons of R ¹ and R ² is 7 or less, the stability of color development and the decoloring property are lowered. Therefore, the carbon number is preferably 8 or more, and more preferably 11 or more.
Preferable examples of R ¹ include the following.

However, q, q ′, q ″, q ′ ″ in the above formulas represent integers satisfying the carbon number of R ¹ and R ² , respectively.
Among them, - _(CH 2) q- are particularly preferred.

Preferred examples of R ² include those shown below.
However, q, q ′, q ″, and q ′ ″ in the formula represent integers that satisfy the carbon number of R ¹ and R ² , respectively.
Among _{them, - (CH 2) q-} CH 3 are particularly preferred.

X represents a divalent group containing an N atom or an O atom, and represents, for example, a divalent group having at least one group represented by the following structural formula.

Preferable examples of the divalent group include groups represented by the following structural formula.

Among these, preferable groups include those represented by the following structural formula.

Preferred examples of the phenol compound having an alkyl chain represented by the general formula (1) include those represented by the following general formula (2) and the following general formula (3).
However, in said general formula (2) and (3), m represents 5-11. n represents 8-22.

Specific examples of the phenol compound represented by the general formula (2) and the general formula (3) are shown below.

-Electron donating color compound-
There is no restriction | limiting in particular as said electron-donating coloring compound, According to the objective, it can select suitably, For example, a leuco dye etc. are mentioned suitably.

  As the leuco dye, a fluorane compound and an azaphthalide compound are suitable. For example, 2-anilino-3-methyl-6-diethylaminofluorane, 2-anilino-3-methyl-6-di (n-butylamino) fluorane 2-anilino-3-methyl-6- (Nn-propyl-N-methylamino) fluorane, 2-anilino-3-methyl-6- (N-isopropyl-N-methylamino) fluorane, 2-anilino -3-methyl-6- (N-isobutyl-N-methylamino) fluorane, 2-anilino-3-methyl-6- (Nn-amyl-N-methylamino) fluorane, 2-anilino-3-methyl -6- (N-sec-butyl-N-methylamino) fluorane, 2-anilino-3-methyl-6- (Nn-amyl-N-ethylamino) Luolan, 2-anilino-3-methyl-6- (N-iso-amyl-N-ethylamino) fluorane, 2-anilino-3-methyl-6- (Nn-propyl-N-isopropylamino) fluorane, 2-anilino-3-methyl-6- (N-cyclohexyl-N-methylamino) fluorane, 2-anilino-3-methyl-6- (N-ethyl-p-toluidino) fluorane, 2-anilino-3-methyl -6- (N-methyl-p-toluidino) fluorane, 2- (m-trichloromethylanilino) -3-methyl-6-diethylaminofluorane, 2- (m-trifluoromethylanilino) -3-methyl -6-diethylaminofluorane, 2- (m-trichloromethylanilino) -3-methyl-6- (N-cyclohexyl-N-methylamino) fluor Lan, 2- (2,4-dimethylanilino) -3-methyl-6-diethylaminofluorane, 2- (N-ethyl-p-toluidino) -3-methyl-6- (N-ethylanilino) fluorane, 2 -(N-ethyl-p-toluidino) -3-methyl-6- (N-propyl-p-toluidino) fluorane, 2-anilino-6- (Nn-hexyl-N-ethylamino) fluorane, 2- (O-chloroanilino) -6-diethylaminofluorane, 2- (o-chloroanilino) -6-dibutylaminofluorane, 2- (m-trifluoromethylanilino) -6-diethylaminofluorane, 2,3-dimethyl -6-dimethylaminofluorane, 3-methyl-6- (N-ethyl-p-toluidino) fluorane, 2-chloro-6-diethylaminofluorane, 2 -Bromo-6-diethylaminofluorane, 2-chloro-6-dipropylaminofluorane, 3-chloro-6-cyclohexylaminofluorane, 3-bromo-6-cyclohexylaminofluorane, 2-chloro-6- ( N-ethyl-N-isoamylamino) fluorane, 2-chloro-3-methyl-6-diethylaminofluorane, 2-anilino-3-chloro-6-diethylaminofluorane, 2- (o-chloroanilino) -3-chloro -6-cyclohexylaminofluorane, 2- (m-trifluoromethylanilino) -3-chloro-6-diethylaminofluorane, 2- (2,3-dichloroanilino) -3-chloro-6-diethylaminofluor Oran, 1,2-benzo-6-diethylaminofluorane, 3-diethylamino-6- (m-tri (Loromethylanilino) fluorane, 3- (1-ethyl-2-methylindol-3-yl) -3- (2-ethoxy-4-diethylaminophenyl) -4-azaphthalide, 3- (1-ethyl-2-) Methylindol-3-yl) -3- (2-ethoxy-4-diethylaminophenyl) -7-azaphthalide, 3- (1-octyl-2-methylindol-3-yl) -3- (2-ethoxy-4) -Diethylaminophenyl) -4-azaphthalide, 3- (1-ethyl-2-methylindol-3-yl) -3- (2-methyl-4-diethylaminophenyl) -4-azaphthalide, 3- (1-ethyl- 2-Methylindol-3-yl) -3- (2-methyl-4-diethylaminophenyl) -7-azaphthalide, 3- (1-ethyl-2-methylindo) Ru-3-yl) -3- (4-diethylaminophenyl) -4-azaphthalide, 3- (1-ethyl-2-methylindol-3-yl) -3- (4-Nn-amyl-N- Methylaminophenyl) -4-azaphthalide, 3- (1-methyl-2-methylindol-3-yl) -3- (2-hexyloxy-4-diethylaminophenyl) -4-azaphthalide, 3,3-bis ( 2-ethoxy-4-diethylaminophenyl) -4-azaphthalide, 3,3-bis (2-ethoxy-4-diethylaminophenyl) -7-azaphthalide, and the like.

In addition to the fluorane compound and the azaphthalide compound, conventionally known leuco dyes can be used as the color former. For example, 2- (p-acetylanilino) -6- (Nn- Amyl-Nn-butylamino) fluorane, 2-benzylamino-6- (N-ethyl-p-toluidino) fluorane, 2-benzylamino-6- (N-methyl-2,4-dimethylanilino) fluorane 2-benzylamino-6- (N-ethyl-2,4-dimethylanilino) fluorane, 2-benzylamino-6- (N-methyl-p-toluidino) fluorane, 2-benzylamino-6- (N -Ethyl-p-toluidino) fluorane, 2- (di-p-methylbenzylamino) -6- (N-ethyl-p-toluidino) fluorane, 2- (α-phenyl ether) Ruamino) -6- (N-ethyl-p-toluidino) fluorane, 2-methylamino-6- (N-methylanilino) fluorane, 2-methylamino-6- (N-ethylanilino) fluorane, 2-methylamino-6 -(N-propylanilino) fluorane, 2-ethylamino-6- (N-methyl-p-toluidino) fluorane, 2-methylamino-6- (N-methyl-2,4-dimethylanilino) fluorane, 2-ethylamino-6- (N-ethyl-2,4-dimethylanilino) fluorane, 2-dimethylamino-6- (N-methylanilino) fluorane, 2-dimethylamino-6- (N-ethylanilino) fluorane, 2-diethylamino-6- (N-methyl-p-toluidino) fluorane, 2-diethylamino-6- (N-ethyl-p-to) Louisino) fluorane, 2-dipropylamino-6- (N-methylanilino) fluorane, 2-dipropylamino-6- (N-ethylanilino) fluorane, 2-amino-6- (N-methylanilino) fluorane, 2-amino -6- (N-ethylanilino) fluorane, 2-amino-6- (N-propylanilino) fluorane, 2-amino-6- (N-methyl-p-toluidino) fluorane, 2-amino-6- (N -Ethyl-p-toluidino) fluorane, 2-amino-6- (N-propyl-p-toluidino) fluorane, 2-amino-6- (N-methyl-p-ethylanilino) fluorane, 2-amino-6- ( N-ethyl-p-ethylanilino) fluorane, 2-amino-6- (N-propyl-p-ethylanilino) fluorane, 2-amino -6- (N-methyl-2,4-dimethylanilino) fluorane, 2-amino-6- (N-ethyl-2,4-dimethylanilino) fluorane, 2-amino-6- (N-propyl- 2,4-dimethylanilino) fluorane, 2-amino-6- (N-methyl-p-chloroanilino) fluorane, 2-amino-6- (N-ethyl-p-chloroanilino) fluorane, 2-amino-6- (N-propyl-p-chloroanilino) fluorane, 1,2-benzo-6- (N-ethyl-N-isoamylamino) fluorane, 1,2-benzo-6-dibutylaminofluorane, 1,2-benzo- 6- (N-methyl-N-cyclohexylamino) fluorane, 1,2-benzo-6- (N-ethyl-N-toluidino) fluorane, and the like.
These may be used alone or mixed, and can be multicolored or full-colored by laminating layers that develop colors having different colors.

The ratio of the color former to the color developer varies in an appropriate range depending on the combination of the compounds to be used, but the color developer is preferably in the range of 0.1 to 20 relative to the color former 1 in a molar ratio. The range of 0.2 to 10 is more preferable. If the amount of the developer is less or more than this range, the density of the colored state is lowered, which causes a problem.
In addition, the color former and the developer can be used in a microcapsule. The ratio of the coloring component to the resin in the heat-sensitive layer is preferably 0.1 to 10 with respect to the coloring component 1, and if it is less than this, the heat intensity of the heat-sensitive layer is insufficient, and if it is more than this, the color density is lowered. Then it becomes a problem.

  In the present invention, a decolorization accelerator in the process of forming an erased state by using the developer and a compound having at least one amide group, urethane group, and urea in the molecule as the decolorization accelerator. The intermolecular interaction is induced between the developer and the developer, and the erasing speed can be remarkably increased.

  The decoloring accelerator may be a compound having at least one amide group, urethane group, and urea in the molecule, and among these, compounds represented by the following general formulas (4) to (10) Is particularly preferred.

R ¹ —NHCO—R ²
... General formula (4)
^{R 1 -NHCO-R 3 -CONH-} R 2 ··· formula (5)
^{R 1 -CONH-R 3 -NHCO-} R 2 ··· formula (6)
R ¹ —NHCOO—R ²
... General formula (7)
^{R 1 -NHCOO-R 3 -OCONH-} R 3 ··· general formula (8)
R < ¹ > -OCONH-R < ³ > -NHCOO-R < ² > ... General formula (9)
In the general formula ^{(4) ~ (10),} R 1, R 2, and ^{R 4} represents a linear alkyl group, branched alkyl group, an unsaturated alkyl group of 7 to 22 carbon atoms. R ³ represents a divalent functional group having 1 to 10 carbon atoms. R ⁵ represents a trivalent functional group having 4 to 10 carbon atoms.

Examples of R ¹ , R ² , and R ⁴ include a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a stearyl group, a behenyl group, and an oleyl group.
Examples of R ³ include a methylene group, an ethylene group, a propylene group, a butylene group, a heptamethylene group, a hexamethylene group, an octamethylene group, a —C ₃ H ₆ OC ₃ H ₆ — group, and —C ₂ H ₄ OC _2. H ₄ - _{group, -C 2 H 4 OC 2 H} 4 OC 2 H 4 - group, and the like.
Preferred examples of R ⁵ include those represented by the following structural formulas.

  Specific examples of the compounds represented by the general formula (4) to the general formula (10) include compounds represented by the following (1) to (81).

(1) C ₁₁ H ₂₃ CONHC ₁₂ H ₂₅ ,
(2) C ₁₅ H ₃₁ CONHC ₁₆ H ₃₃ ,
(3) C ₁₇ H ₃₅ CONHC ₁₈ H ₃₇ ,
(4) C ₁₇ H ₃₅ CONHC ₁₈ H ₃₅ ,
(5) C ₂₁ H ₄₁ CONHC ₁₈ H ₃₇ ,
(6) C ₁₅ H ₃₁ CONHC ₁₈ H ₃₇ ,
(7) C ₁₇ H ₃₅ CONHCH ₂ NHCOC ₁₇ H ₃₅ ,
(8) C ₁₁ H ₂₃ CONHCH ₂ NHCOC ₁₁ H ₂₃ ,
_{(9) C 7 H 15 CONHC} 2 H 4 NHCOC 17 H 35,
(10) C ₉ H ₁₉ CONHC ₂ H ₄ NHCOC ₉ H ₁₉ ,
(11) C ₁₁ H ₂₃ CONHC ₂ H ₄ NHCOC ₁₁ H ₂₃ ,
(12) C ₁₇ H ₃₅ CONHC ₂ H ₄ NHCOC ₁₇ H ₃₅ ,
_{(13) (CH 3) 2} CHC 14 H 35 CONHC 2 H 4 NHCOC 14 H 35 (CH 3) 2,
(14) C ₂₁ H ₄₃ CONHC ₂ H ₄ NHCOC ₂₁ H ₄₃ ,
(15) C ₁₇ H ₃₅ CONHC ₆ H ₁₂ NHCOC ₁₇ H ₃₅ ,
(16) C ₂₁ H ₄₃ CONHC ₆ H ₁₂ NHCOC ₂₁ H ₄₃ ,
(17) C ₁₇ H ₃₃ CONHCH ₂ NHCOC ₁₇ H ₃₃ ,
_{(18) C 17 H 33 CONHC} 2 H 4 NHCOC 17 H 33,
(19) C ₂₁ H ₄₁ CONHC ₂ H ₄ NHCOC ₂₁ H ₄₁ ,
_{(20) C 17 H 33 CONHC} 6 H 12 NHCOC 17 H 33,
(21) C ₈ H ₁₇ NHCOC ₂ H ₄ CONHC ₁₈ H ₃₇ ,
(22) C ₁₀ H ₂₁ NHCOC ₂ H ₄ CONHC ₁₀ H ₂₁ ,
(23) C ₁₂ H ₂₅ NHCOC ₂ H ₄ CONHC ₁₂ H ₂₅ ,
(24) C ₁₈ H ₃₇ NHCOC ₂ H ₄ CONHC ₁₈ H ₃₇ ,
(25) C ₂₁ H ₄₃ NHCOC ₂ H ₄ CONHC ₂₁ H ₄₃ ,
_{(26) C 18 H 37 NHCOC} 6 H 12 CONHC 18 H 37,
_{(27) C 18 H 35 NHCOC} 4 H 8 CONHC 18 H 35,
_{(28) C 18 H 35 NHCOC} 8 H 16 CONHC 18 H 35,
(29) C ₁₂ H ₂₅ OCONHC ₁₈ H ₃₇ ,
(30) C ₁₃ H ₂₇ OCONHC ₁₈ H ₃₇ ,
(31) C ₁₆ H ₃₃ OCONHC ₁₈ H ₃₇ ,
(32) C ₁₈ H ₃₇ OCONHC ₁₈ H ₃₇ ,
(33) C ₂₁ H ₄₃ OCONHC ₁₈ H _37,
(34) C ₁₂ H ₂₅ OCONHC ₁₆ H ₃₃ ,
(35) C ₁₃ H ₂₇ OCONHC ₁₆ H ₃₃ ,
(36) C ₁₆ H ₃₃ OCONHC ₁₆ H ₃₃ ,
(37) C ₁₈ H ₃₇ OCONHC ₁₆ H ₃₃ ,
(38) C ₂₁ H ₄₃ OCONHC ₁₆ H ₃₃ ,
(39) C ₁₂ H ₂₅ OCONHC ₁₄ H ₂₉ ,
(40) C ₁₃ H ₂₇ OCONHC ₁₄ H ₂₉ ,
(41) C ₁₆ H ₃₃ OCONHC ₁₄ H ₂₉ ,
(42) C ₁₈ H ₃₇ OCONHC ₁₄ H ₂₉ ,
(43) C ₂₂ H ₄₅ OCONHC ₁₄ H ₂₉ ,
(44) C ₁₂ H ₂₅ OCONHC ₁₂ H ₃₇ ,
(45) C ₁₃ H ₂₇ OCONHC ₁₂ H ₃₇ ,
(46) C ₁₆ H ₃₃ OCONHC ₁₂ H ₃₇ ,
(47) C ₁₈ H ₃₇ OCONHC ₁₂ H ₃₇ ,
(48) C ₂₁ H ₄₃ OCONHC ₁₂ H ₃₇ ,
(49) C ₂₂ H ₄₅ OCONHC ₁₈ H ₃₇ ,
(50) C ₁₈ H ₃₇ NHCOOC ₂ H ₄ OCONHC ₁₈ H ₃₇ ,
(51) C ₁₈ H ₃₇ NHCOOC ₃ H ₆ OCONHC ₁₈ H ₃₇ ,
(52) C ₁₈ H ₃₇ NHCOOC ₄ H ₈ OCONHC ₁₈ H ₃₇ ,
(53) C ₁₈ H ₃₇ NHCOOC ₆ H ₁₂ OCONHC ₁₈ H ₃₇ ,
(54) C ₁₈ H ₃₇ NHCOOC ₈ H ₁₆ OCONHC ₁₈ H ₃₇ ,
(55) C ₁₈ H ₃₇ NHCOOC ₂ H ₄ OC ₂ H ₄ OCONHC ₁₈ H ₃₇ ,
(56) C ₁₈ H ₃₇ NHCOOC ₃ H ₆ OC ₃ H ₆ OCONHC ₁₈ H ₃₇ ,
(57) C ₁₈ H ₃₇ NHCOOC ₁₂ H ₂₄ OCONHC ₁₈ H ₃₇ ,
(58) C ₁₈ H ₃₇ NHCOOC ₂ H ₄ OC ₂ H ₄ OC ₂ H ₄ OCONHC ₁₈ H ₃₇ ,
(59) C ₁₆ H ₃₃ NHCOOC ₂ H ₄ OCONHC ₁₆ H ₃₃ ,
(60) C ₁₆ H ₃₃ NHCOOC ₃ H ₆ OCONHC ₁₆ H ₃₃ ,
(61) C ₁₆ H ₃₃ NHCOOC ₄ H ₈ OCONHC ₁₆ H ₃₃ ,
(62) C ₁₆ H ₃₃ NHCOOC ₆ H ₁₂ OCONHC ₁₆ H ₃₃ ,
(63) C ₁₆ H ₃₃ NHCOOC ₈ H ₁₆ OCONHC ₁₆ H ₃₃ ,
(64) C ₁₈ H ₃₇ OCOHNC ₆ H ₁₂ NHCOOC ₁₈ H ₃₇ ,
(65) C ₁₆ H ₃₃ OCOHNC ₆ H ₁₂ NHCOOC ₁₆ H ₃₃ ,
_{(66) C 14 H 29 OCOHNC} 6 H 12 NHCOOC 14 H 29,
_{(67) C 12 H 25 OCOHNC} 6 H 12 NHCOOC 12 H 25,
_{(68) C 10 H 21 OCOHNC} 6 H 12 NHCOOC 10 H 21,
_{(69) C 8 H 17 OCOHNC} 6 H 12 NHCOOC 8 H 17,

  The addition amount of the decolorization accelerator is preferably 0.1 to 300 parts by mass, more preferably 3 to 100 parts by mass with respect to 100 parts by mass of the developer. When the addition amount is less than 0.1 parts by mass, the effect of adding the decoloring accelerator may not be exhibited. When the addition amount exceeds 300 parts by mass, the color density may decrease.

  In addition to the above components, the heat-sensitive layer can contain a binder resin and, if necessary, various additives for improving and controlling the coating characteristics and color-decoloring / decoloring characteristics of the heat-sensitive layer. Examples of these additives include a crosslinking agent, a crosslinking accelerator, a filler, a lubricant, a surfactant, a conductive agent, a filler, an antioxidant, a light stabilizer, and a color stabilizer.

-Binder resin-
Examples of the binder resin include polyvinyl chloride, polyvinyl acetate, vinyl chloride vinyl acetate copolymer, ethyl cellulose, polystyrene, styrene copolymer, phenoxy resin, polyester, aromatic polyester, polyurethane, polycarbonate, and polyacrylic acid. Examples thereof include esters, polymethacrylic acid esters, acrylic copolymers, maleic acid copolymers, polyvinyl alcohol, modified polyvinyl alcohol, hydroxyethyl cellulose, carboxymethyl cellulose, and starches.
The role of these binder resins is to keep the materials of the composition uniformly dispersed without being displaced by the application of heat for recording and erasing. Therefore, it is preferable to use a resin having high heat resistance as the binder resin. For example, the binder resin may be cross-linked by heat, ultraviolet light, electron beam or the like (resin in a cross-linked state).

  The resin in the crosslinked state is not particularly limited and can be appropriately selected depending on the purpose. For example, acrylic polyol resin, polyester polyol resin, polyurethane polyol resin, phenoxy resin, polyvinyl butyral resin, cellulose acetate propio Examples thereof include a resin having a group that reacts with a crosslinking agent, such as nate and cellulose acetate butyrate, or a resin obtained by copolymerizing a monomer having a group that reacts with a crosslinking agent and other monomers.

  Examples of the crosslinking agent include conventionally known isocyanates, amines, phenols, and epoxy compounds. Among these, an isocyanate type crosslinking agent is preferably used. The isocyanate compound used here is selected from known modified monomers such as urethane modified products, allophanate modified products, isocyanurate modified products, burette modified products, carbodiimide modified products, and blocked isocyanates. Examples of the isocyanate monomer forming the modified product include tolylene diisocyanate (TDI), 4,4'-diphenylmethane diisocyanate (MDI), xylylene diisocyanate (XDI), naphthylene diisocyanate (NDI), paraphenylene diisocyanate ( PPDI), tetramethylxylylene diisocyanate (TMXDI), hexamethylene diisocyanate (HDI), dicyclohexylmethane diisocyanate (HMDI), isophorone diisocyanate (IPDI), lysine diisocyanate (LDI), isopropylidenebis (4-cyclohexylisocyanate) (IPC) ), Cyclohexyl diisocyanate (CHDI), tolidine diisocyanate (TODI), and the like. It is not limited to the compounds.

  Further, a catalyst used for this kind of reaction may be used as the crosslinking accelerator. Examples of the crosslinking accelerator include tertiary amines such as 1,4-diaza-bicyclo [2,2,2] octane, and metal compounds such as organic tin compounds. The total amount of the crosslinking agent may or may not undergo a crosslinking reaction. That is, an unreacted crosslinking agent may be present. Since this type of cross-linking reaction proceeds over time, the presence of an unreacted cross-linking agent does not indicate that the cross-linking reaction has not proceeded at all, but an unreacted cross-linking agent is detected. However, this does not mean that there is no resin in a crosslinked state. Further, as a method for distinguishing whether the polymer in the present invention is in a crosslinked state or in a non-crosslinked state, it can be distinguished by immersing the coating film in a highly soluble solvent. That is, since the polymer in the non-crosslinked state dissolves in the solvent and does not remain in the solute, the presence or absence of the polymer structure of the solute may be analyzed. Therefore, if the presence of a polymer structure in the solute cannot be confirmed, it can be said that the polymer is in a non-crosslinked state, and can be distinguished from a crosslinked polymer. Here, this can be expressed as a gel fraction.

  The gel fraction means the ratio of gel formation when a resin solute in a solvent loses its independent mobility due to interaction and aggregates and forms a state (gel). The resin preferably has a gel fraction of 30% or more, more preferably 50% or more, still more preferably 70% or more, and particularly preferably 80% or more. When the gel fraction is small, repeated durability is lowered. Therefore, in order to improve the gel fraction, a curable resin that is cured by heat, UV, EB, or the like is mixed in the resin, or the resin itself is crosslinked. Good.

Here, as the method for measuring the gel fraction, the membrane is peeled off from the support and the initial mass of the membrane is measured, and then the membrane is sandwiched between 400 mesh wire nets in a solvent in which the resin before crosslinking is soluble. It is possible to measure the mass after drying by soaking in a vacuum for 24 hours and then vacuum drying.
The gel fraction calculation can be performed by the following formula 1.
<Formula 1>
Gel fraction (%) = [mass after drying (g) / initial mass (g)] × 100
When the gel fraction is calculated by this calculation, the calculation is performed excluding the mass of organic low-molecular substance particles other than the resin component in the heat-sensitive layer. At this time, when the mass of the organic low molecular weight substance is not known in advance, the mass ratio is obtained from the area ratio per unit area and the specific gravity of the resin and the organic low molecular weight substance by cross-sectional observation such as TEM and SEM. The gel fraction value may be calculated by calculating the mass of the low molecular substance.

  In the measurement of the gel fraction, a heat-sensitive layer is provided on the support, and another layer such as a protective layer is laminated thereon, or between the support and the heat-sensitive layer. When there are other layers, as described above, first, the film thickness of the heat-sensitive layer and other layers is examined by cross-sectional observation of the above-described TEM, SEM, etc. The gel fraction measurement may be performed in the same manner as in the measurement method by shaving to expose the surface of the heat sensitive layer and peeling the heat sensitive layer.

  In addition, in this method, when there is a protective layer made of an ultraviolet curable resin or the like in the upper layer of the heat sensitive layer, in order to prevent this layer from mixing as much as possible, the thickness of the protective layer is reduced and the surface of the heat sensitive layer is slightly It is necessary to prevent the influence on the shaving gel fraction value.

The filler can be divided into an inorganic filler and an organic filler. Examples of the inorganic filler include calcium carbonate, magnesium carbonate, silicic anhydride, alumina, iron oxide, calcium oxide, magnesium oxide, chromium oxide, manganese oxide, silica, talc, and mica.
Examples of the organic filler include silicone resin, cellulose resin, epoxy resin, nylon resin, phenol resin, polyurethane resin, urea resin, melamine resin, polyester resin, polycarbonate resin, polystyrene, polystyrene / isoprene, styrene vinylbenzene, and other styrene resins. Acrylic resins such as vinylidene chloride acrylic, acrylic urethane and ethylene acrylic, polyethylene resins, formaldehyde resins such as benzoguanamine formaldehyde and melamine formaldehyde, polymethyl methacrylate resins, vinyl chloride resins and the like. In the present invention, the filler can be used alone, but two or more kinds may be included. In the case of a plurality, there is no particular limitation on how to combine the inorganic filler and the organic filler. Examples of the shape include a spherical shape, a granular shape, a plate shape, and a needle shape. The filler content in the heat-sensitive layer is a volume fraction, and is usually preferably 0.5 to 50% by volume.

Examples of the lubricant include synthetic waxes such as ester wax, paraffin wax, and polyethylene wax: vegetable waxes such as hardened castor oil: animal waxes such as beef tallow hardened oil: higher alcohols such as stearyl alcohol and behenyl alcohol: Higher fatty acids such as margaric acid, lauric acid, mystynolic acid, palmitic acid, stearic acid, behenic acid, and fumenic acid: higher fatty acid esters such as sorbitan fatty acid ester: stearic acid amide, oleic acid amide, lauric acid amide, ethylene Examples thereof include amides such as bis-stearic acid amide, methylene bis-stearic acid amide, and methylol stearic acid amide.
The content of the lubricant in the heat-sensitive layer is preferably from 0.1 to 95%, more preferably from 1 to 75%, in terms of volume fraction.

The surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include an anionic surfactant, a cationic surfactant, a nonionic surfactant, and an amphoteric surfactant. Can be mentioned.
The plasticizer is not particularly limited and may be appropriately selected depending on the purpose. For example, phosphoric acid ester, fatty acid ester, phthalic acid ester, dibasic acid ester, glycol, polyester plasticizer, epoxy plasticizer Agents, and the like.

  The method for forming the heat-sensitive layer is not particularly limited and may be appropriately selected depending on the intended purpose. For example, (1) the resin, the electron-donating color-forming compound, and the electron-accepting compound are contained in a solvent. A method in which a coating solution for a heat-sensitive layer dissolved or dispersed in is coated on a support, and the solvent is evaporated to form a sheet or the like, or at the same time or thereafter, (2) a solvent in which only the resin is dissolved A method in which a coating solution for a heat-sensitive layer in which the electron-donating color-forming compound and the electron-accepting compound are dispersed is applied on a support, and the solvent is evaporated to form a sheet or the like, or at the same time or thereafter, 3) A method in which the resin, the electron-donating coloring compound and the electron-accepting compound are heated and melted and mixed with each other without using a solvent, and the molten mixture is formed into a sheet or the like and cooled and then crosslinked. Etc. That. In these, it is also possible to form a sheet-like reversible thermosensitive recording medium without using the support.

The solvent used in (1) or (2) varies depending on the type of the resin and the electron-donating color-forming compound and the electron-accepting compound, and cannot be defined unconditionally. For example, tetrahydrofuran, methyl ethyl ketone, Examples include methyl isobutyl ketone, chloroform, carbon tetrachloride, ethanol, toluene, benzene, and the like.
The electron-accepting compound is dispersed in the form of particles in the heat-sensitive layer.

Various pigments, antifoaming agents, pigments, dispersants, slip agents, preservatives, crosslinking agents, plasticizers, etc. are added to the coating solution for the heat sensitive layer for the purpose of expressing high performance as a coating material. May be.
The method for applying the heat-sensitive layer is not particularly limited and may be appropriately selected depending on the intended purpose. A support that has been cut in a roll or continuously or into a sheet is transported on the support. For example, blade coating, wire bar coating, spray coating, air knife coating, bead coating, curtain coating, gravure coating, kiss coating, reverse roll coating, dip coating, die coating, etc. Apply by the method.
There is no restriction | limiting in particular as drying conditions of the said coating liquid for heat sensitive layers, According to the objective, it can select suitably, For example, about 10 minutes-about 1 hour at the temperature of room temperature-140 degreeC etc. are mentioned.

  The resin in the heat-sensitive layer can be cured by heating, ultraviolet irradiation, electron beam irradiation, or the like. As a method for curing by these means, specifically, curing is performed by reacting an acrylic copolymer (acrylic resin) with a polyisocyanate compound.

The said ultraviolet irradiation can be performed using a well-known ultraviolet irradiation apparatus, As this apparatus, what was provided with the light source, the lamp, the power supply, the cooling device, the conveying apparatus etc. is mentioned, for example.
Examples of the light source include a mercury lamp, a metal halide lamp, a potassium lamp, a mercury xenon lamp, and a flash lamp. The wavelength of the light source can be appropriately selected according to the ultraviolet absorption wavelength of the photopolymerization initiator and photopolymerization accelerator added to the reversible thermosensitive recording medium composition.
The conditions for the ultraviolet irradiation are not particularly limited and may be appropriately selected depending on the purpose. For example, the lamp output, the conveyance speed, etc. may be determined according to the irradiation energy necessary for crosslinking the resin. .

The electron beam irradiation can be performed using a known electron beam irradiation apparatus, and the electron beam irradiation apparatus can be roughly classified into two types, a scanning type (scan beam) and a non-scanning type (area beam). Conditions can be selected according to the irradiation area, irradiation dose, and the like. Further, the electron beam irradiation conditions can be determined from the following formula in consideration of the electron flow, the irradiation width, and the conveyance speed in accordance with the dose necessary for crosslinking the resin.
D = (△ E / △ R) ・ η ・ I / (W ・ V)
In the above formula, D represents a required dose (Mrad). ΔE / ΔR represents average energy loss. η represents efficiency. I represents the electron current (mA). W represents the irradiation width (cm). V represents a conveyance speed (cm / s).
Industrially, it is preferable to simplify the mathematical formula and use the following mathematical formula.
D ・ V = K ・ I / W
The device rating is represented by Mrad · m / min, and the electron current rating is selected to be about 20 to 500 mA.

There is no restriction | limiting in particular in the film thickness of the said thermosensitive layer, According to the objective, it can select suitably, For example, 1-20 micrometers is preferable and 3-15 micrometers is more preferable.
If the thickness of the heat-sensitive layer is too thin, the color density will be low, and the contrast of the image may be low. May occur, making it impossible to obtain a desired color density.

  The reversible thermosensitive recording medium of the present invention is an intermediate layer, a protective layer, a back layer, an undercoat layer, a photothermal conversion layer, a colored layer, an air layer, a light, as appropriate, in addition to the thermosensitive layer. You may have other layers, such as a reflection layer, an adhesive layer, a protective layer, an adhesive bond layer, and an adhesion layer. Each of these layers may have a single layer structure or a laminated structure.

-Intermediate layer-
In the reversible thermosensitive recording medium, an intermediate layer can be provided between the protective layer and the thermosensitive layer for the purpose of protecting the thermosensitive layer from the solvent or monomer component of the protective layer forming liquid (for example, a special layer). (See Kaihei 1-133781).
As the material for the intermediate layer, resin components such as a thermoplastic resin and a thermosetting resin can be used in addition to those mentioned as the material for the binder resin in the heat-sensitive layer. Examples of the resin component include polyethylene, polypropylene, polystyrene, polyvinyl alcohol, polyvinyl butyral, polyurethane, saturated polyester, unsaturated polyester, epoxy resin, phenol resin, polycarbonate, polyamide, and the like.

The intermediate layer preferably contains an ultraviolet absorber. As the ultraviolet absorber, any of organic and inorganic compounds can be used.
Examples of the organic ultraviolet absorber include benzotriazole-based, benzophenone-based, salicylic acid ester-based, cyanoacrylate-based, and cinnamic acid-based ultraviolet absorbers, with benzotriazole-based being preferred. Among these, those in which a hydroxyl group is protected with an adjacent bulky functional group are particularly preferred, and 2- (2′-hydroxy-3 ′, 5′-di-t-butylphenyl) benzotriazole, 2- (2 '-Hydroxy-3'-t-butyl-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-3', 5'-di-t-butylphenyl) -5-chlorobenzotriazole, 2- (2′-hydroxy-3′-t-butyl-5′-methylphenyl) -5-chlorobenzotriazole and the like are preferable. A skeleton having such an ultraviolet absorbing ability may be pendant to a copolymerized polymer such as an acrylic resin or a styrene resin.
As for content of the said organic type ultraviolet absorber, 0.5-10 mass% is preferable with respect to the resin component total mass of the said intermediate | middle layer.

As the inorganic ultraviolet absorber, a metal compound having an average particle size of 100 nm or less is suitable. For example, zinc oxide, indium oxide, alumina, silica, zirconia, tin oxide, cerium oxide, iron oxide, antimony oxide, Barium oxide, calcium oxide, barium oxide, bismuth oxide, nickel oxide, magnesium oxide, chromium oxide, manganese oxide, tantalum oxide, niobium oxide, thorium oxide, hafnium oxide, molybdenum oxide, iron ferrite, nickel ferrite, cobalt ferrite, titanic acid Metal oxides such as barium and potassium titanate or composite oxides thereof, zinc sulfide, metal sulfides or sulfate compounds such as barium sulfate, titanium carbide, silicon carbide, molybdenum carbide, tungsten carbide, tantalum carbide Metal carbides, such as carbide, aluminum nitride, silicon nitride, boron nitride, zirconium nitride, vanadium nitride, titanium nitride, niobium nitride, and metal nitrides such as gallium nitride. Among these, metal oxide ultrafine particles are preferable, and silica, alumina, zinc oxide, titanium oxide, and cerium oxide are more preferable. These can also be treated with silicone, wax, organosilane, silica or the like on the surface.
The content of the inorganic ultraviolet absorber is preferably in the range of 1 to 95% in terms of volume fraction. These organic and inorganic ultraviolet absorbers may be contained in the heat sensitive layer.

  The thickness of the intermediate layer is preferably 0.1 to 20 μm, and more preferably 0.5 to 5 μm. As the solvent used in the intermediate layer coating liquid, the coating liquid dispersing device, the intermediate layer coating method, the intermediate layer drying / curing method, etc., known methods used in the heat-sensitive layer can be used.

  Moreover, according to this invention, the protective layer containing resin in a crosslinked state can be provided on a heat sensitive layer. As the resin used for the protective layer, the same thermosetting resin, ultraviolet curable resin, and electron beam curable resin as those of the above-mentioned thermosensitive layer are used.

  Improvement of adhesion between the heat-sensitive layer and the protective layer, prevention of alteration of the heat-sensitive layer by application of the protective layer, the additive contained in the protective layer moves to the heat-sensitive layer, or the additive contained in the heat-sensitive layer moves to the protective layer In order to prevent this, an intermediate layer may be provided between the two. The thickness of the intermediate layer is preferably from 0.1 to 20 μm, more preferably from 0.3 to 10 μm. As the solvent used in the intermediate layer coating liquid, the coating liquid dispersing device, the binder, the coating method, the drying / curing method, and the like, the known methods used in the thermosensitive layer can be used.

  In forming the protective layer, the thickness of the protective layer is preferably 0.1 to 20 μm, and more preferably 0.3 to 10 μm. As the solvent, the coating liquid dispersing device, the binder, the coating method, the drying / curing method, and the like used in the protective layer coating solution, known methods used in the heat-sensitive layer can be used.

In order to improve the transportability, the back layer is not particularly limited as long as it is formed on the surface (back surface) opposite to the surface on which the heat-sensitive layer of the support is provided, and can be appropriately selected according to the purpose. One or more layers may be formed, and the exposed outermost surface (outermost surface) is particularly preferable.
The back layer contains other components such as a binder resin, a filler, a lubricant, and a color pigment.
Examples of the inorganic filler include carbonates, silicates, metal oxides, sulfate compounds, and the like. Examples of the organic filler include silicone resin, cellulose resin, epoxy resin, nylon resin, phenol resin, polyurethane resin, urea resin, melamine resin, polyester resin, polycarbonate resin, styrene resin, acrylic resin, polyethylene resin, formaldehyde Resin, polymethyl methacrylate resin, and the like.
There is no restriction | limiting in particular in the film thickness of the said back layer, According to the objective, it can select suitably, 0.1-20 micrometers is preferable and 0.3-10 micrometers is more preferable.

In the reversible thermosensitive recording medium, a heat insulating undercoat layer can be provided between the support and the thermosensitive layer in order to effectively use the applied heat. The undercoat layer can be formed by coating using a binder resin containing organic or inorganic fine hollow particles. It is also possible to provide an undercoat layer for the purpose of improving the adhesion between the support and the heat-sensitive layer and preventing the heat-sensitive layer material from penetrating into the support.
For the undercoat layer, a resin similar to the resin for the heat sensitive layer or the protective layer can be used. Further, the heat-sensitive layer and the undercoat layer can contain at least one of inorganic fillers such as calcium carbonate, magnesium carbonate, titanium oxide, silicon oxide, aluminum hydroxide, kaolin, and talc, and various organic fillers. In addition, a lubricant, a surfactant, a dispersant, and the like can be contained.

  The reversible thermosensitive recording medium is preferably provided with a colored layer for the purpose of improving visibility between the support and the thermosensitive layer. The colored layer can be formed by applying a solution or dispersion containing a colorant and a resin binder to a target surface and drying, or simply pasting a colored sheet.

  The reversible thermosensitive recording medium can be provided with a color printing layer. Examples of the colorant in the color printing layer include various dyes and pigments contained in color inks used in conventional full color printing. Examples of the resin binder include various thermoplastic, thermosetting, ultraviolet curable, and electron beam curable resins. Since the thickness of the color printing layer is appropriately changed with respect to the printing color density, it can be selected according to the desired printing color density.

The reversible thermosensitive recording medium may have a non-adhered portion due to an air layer between the support and the thermosensitive layer. Since the refractive index of the organic polymer compound used in the heat-sensitive layer is about 1.4 to 1.6 and has a large difference from the refractive index of air 1.0, the heat-sensitive layer has the air layer. When light is reflected at the interface between the heat-sensitive layer and the heat-sensitive layer, the turbidity can be amplified when the heat-sensitive layer is cloudy, and the visibility can be improved. Can be suitably used.
Since the air layer also functions as a heat insulating layer, it can improve the heat sensitivity, and also functions as a cushion layer, and can disperse the pressure from the thermal head. It is possible to prevent surface abrasion or the like due to natural force and to improve durability repeatedly.

  The reversible thermosensitive recording medium may be provided with a head matching layer. Examples of the material of the head matching layer include a heat resistant resin and an inorganic pigment. As the heat resistant resin, the same heat resistant resin as that used in the protective layer is preferably used. Examples of the inorganic pigment include calcium carbonate, kaolin, silica, aluminum hydroxide, alumina, aluminum silicate, magnesium hydroxide, magnesium carbonate, magnesium oxide, titanium oxide, zinc oxide, barium sulfate, and talc. . These may be used individually by 1 type and may use 2 or more types together. As a particle size of the said inorganic pigment, 0.01-10.0 micrometers is preferable, for example, and 0.05-8.0 micrometers is more preferable. The added amount of the inorganic pigment is preferably 0.001 to 2 parts by mass, more preferably 0.005 to 1 part by mass with respect to 1 part by mass of the heat resistant resin.

In order to enable laser recording, a photothermal conversion layer that absorbs laser light and converts light energy to heat energy may be provided between the support and the heat sensitive layer.
Further, at least one printed layer may be provided in order to improve the design of the heat sensitive layer.

  In addition, when the resin contained in the protective layer, the color printing layer, and the head matching layer is cured by heat, ultraviolet light, electron beam, or the like, it is used for crosslinking the resin of the back layer and the heat sensitive layer. It is preferable to add a crosslinking agent, a photopolymerization initiator, and a photopolymerization accelerator.

  The reversible thermosensitive recording medium of the present invention can be processed into a desired shape according to the application, for example, processed into a card shape, a sheet shape, a roll shape, or the like. As for the processed card, it can be applied to prepaid cards, point cards, and credit cards. If the sheet size is larger than the card size, the printing range is widened, so it can be used for general documents, process management instructions, and the like.

The reversible thermosensitive recording medium of the present invention may be used in combination with an irreversible thermosensitive layer. In this case, the color tone of each heat sensitive layer may be the same or different. Also, printing such as offset printing, gravure printing, or ink jet printer, thermal transfer printer, sublimation printer on the same or part of the same surface as the heat-sensitive layer of the reversible thermosensitive recording medium of the present invention and / or a part of the opposite surface. For example, a colored layer with an arbitrary pattern may be provided, and an OP varnish layer mainly composed of a curable resin may be provided on a part or the entire surface of the colored layer. Examples of the arbitrary pattern include characters, patterns, patterns, photographs, information detected by infrared rays, and the like. It is also possible to add a dye or pigment to any one of the simply configured layers for coloring.
Furthermore, the reversible thermosensitive recording medium of the present invention can be provided with a hologram for security. In addition, in order to impart design properties, it is possible to provide a relief image, an intaglio shape, or a design such as a person image, a company emblem, or a symbol mark.

  Formation and deletion of an image on the reversible thermosensitive recording medium can be performed using a known image processing apparatus, and is preferably performed using the image processing apparatus of the present invention described later.

  As the image processing apparatus, for example, an apparatus including an image forming unit for forming an image on the reversible thermosensitive recording medium and an image erasing unit for erasing the image is preferably exemplified. Among these, in view of the short processing time, it is preferable to include an image forming and erasing unit that serves as both the image forming unit and the image erasing unit. An image processing device that can process an image by changing the energy applied to the head, or the image forming means is a thermal head, the image erasing means is a thermal head, and a ceramic heater (a heating resistor is screen-printed on an alumina substrate) Heating element), hot stamp, heat roller, contact block type means for bonding heating elements such as heat blocks, or hot air or infrared An image processing device selected from one of the non-contact means using the like.

(Reversible thermosensitive recording material)
In the reversible thermosensitive recording member of the present invention, the thermosensitive layer capable of reversible display and the information storage unit are provided (integrated) on the same card, and a part of the stored information of the information storage unit is displayed on the thermosensitive layer. By doing so, the cardholder can check the information just by looking at the card without a special device, which is excellent in convenience. Further, when the contents of the information storage unit are rewritten, the reversible thermosensitive recording medium can be repeatedly used by rewriting the display of the reversible thermosensitive recording unit.
The information storage unit is not particularly limited, and for example, a magnetic thermosensitive layer, a magnetic stripe, an IC memory, an optical memory, an RF-ID tag, or the like is preferably used. In particular, in a sheet medium having a size larger than the card size, an IC memory and an RF-ID tag are preferably used. The RF-ID tag includes an IC chip and an antenna connected to the IC chip.
As the magnetic heat-sensitive layer, commonly used iron oxide, barium ferrite, etc. and vinyl chloride-based, urethane-based resin, nylon-based resin, etc. are used, and are formed on a support by a method such as vapor deposition / sputtering. It is formed without using a resin. The magnetic heat-sensitive layer may be provided on the surface of the support opposite to the heat-sensitive layer, or may be provided between the support and the heat-sensitive layer and on a part of the heat-sensitive layer. Further, a reversible thermosensitive recording material used for display may be used in the storage unit by a barcode, a two-dimensional code, or the like. Of these, magnetic recording and IC are more preferable.

  More specifically, it can be particularly preferably used in the following reversible thermosensitive recording label, reversible thermosensitive recording member, image processing apparatus, image processing method, and the like of the present invention. In the present invention, the surface of the reversible thermosensitive recording medium means the surface of the thermosensitive layer side, and is not limited to the protective layer, but contacts the thermal head when erasing printing such as the surface of the printing layer or the surface of the OP layer. Means all or part of the face.

The reversible thermosensitive recording member of the present invention has the thermosensitive layer capable of reversible display and an information storage unit, and a suitable example of the information storage unit is an RF-ID tag. FIG. 2 shows a schematic diagram of the RF-ID tag 85. The RF-ID tag 85 includes an IC chip 81 and an antenna 82 connected to the IC chip. The IC chip 81 is divided into a storage unit, a power supply adjustment unit, a transmission unit, and a reception unit, and each performs communication by sharing the function. In the communication, the RF-ID tag and the reader / writer antenna communicate with each other by radio waves to exchange data. Specifically, an RF-ID antenna receives a radio wave from a reader / writer, and an electromotive force is generated by electromagnetic induction or the like by a resonance action. This activates the IC chip in the RF-ID tag, converts the information in the chip into a signal, and then transmits a signal from the RF-ID tag. This information is received by the antenna on the reader / writer side and recognized by the data processing device, and data processing is performed on the software side.
The RF-ID tag is processed into a label or a card, and the RF-ID tag 85 can be attached to the reversible thermosensitive recording medium of the present invention as shown in FIG. The RF-ID tag 85 can be attached to the heat-sensitive layer surface or the back layer surface, but is preferably attached to the back layer surface. A known adhesive or pressure-sensitive adhesive can be used to bond the RF-ID tag and the reversible thermosensitive recording medium.

FIG. 4 shows an example in which the reversible thermosensitive recording medium is applied to an industrial rewritable sheet (reversible thermosensitive recording member) 90. As shown in FIG. 4A, a rewritable display section is provided on the thermosensitive layer side. An RF-ID tag may be attached to the back surface (back layer) as shown in FIG. 4B, or an RF-ID tag may be attached as shown in FIG. However, those having an RF-ID tag are preferable in terms of convenience.
FIG. 5 shows an example of how to use an industrial rewritable sheet in which the reversible thermosensitive recording medium (rewritable sheet) of the present invention is combined with an RF-ID tag. First, information such as an article name and quantity is recorded on a sheet and an RF-ID tag with respect to delivered raw materials, and attached to a returnable box or the like for inspection. In the next process, a processing instruction is given to the delivered raw material, information is recorded in the rewritable sheet and the RF-ID tag, and a processing instruction document is obtained, and the process proceeds to the processing process. Next, the processed product is attached with a rewritable sheet on which ordering information is recorded as an ordering instruction and an RF-ID tag. After the product is shipped, the rewritable sheet is collected, the shipping information is read, and used again as an invoice.

(Reversible thermosensitive recording label)
The reversible thermosensitive recording label of the present invention comprises a surface opposite to the image-forming surface of the reversible thermosensitive recording medium of the present invention (if the thermosensitive layer is provided on a support, The surface opposite to the surface on which the heat-sensitive layer is formed has at least one of an adhesive layer and a pressure-sensitive adhesive layer, and further has other layers appropriately selected as necessary. For example, for a reversible thermosensitive recording label, an adhesive layer or a pressure-sensitive adhesive layer is formed (no release paper type), and a release paper is attached under the adhesive layer or the pressure-sensitive adhesive layer (release paper type) There is.

The shape, structure, size and the like of the adhesive layer to the pressure-sensitive adhesive layer are not particularly limited and may be appropriately selected depending on the purpose. For example, the shape may be a sheet shape, a film shape, or the like. The structure may be a single-layer structure or a laminated structure, and the size may be larger or smaller than the heat-sensitive layer.
The material of the adhesive layer to the pressure-sensitive adhesive layer is not particularly limited and may be appropriately selected depending on the intended purpose. For example, urea resin, melamine resin, phenol resin, epoxy resin, vinyl acetate resin, acetic acid Vinyl-acrylic copolymer, ethylene-vinyl acetate copolymer, acrylic resin, polyvinyl ether resin, vinyl chloride-vinyl acetate copolymer, polystyrene resin, polyester resin, polyurethane resin, polyamide resin Chlorinated polyolefin resin, polyvinyl butyral resin, acrylic ester copolymer, methacrylic ester copolymer, natural rubber, cyanoacrylate resin, silicone resin, and the like. These may be used individually by 1 type, may use 2 or more types together, may be a hot melt type, may use a release paper, and may be a non-release paper type.

When the reversible thermosensitive recording label has at least one of the adhesive layer and the pressure-sensitive adhesive layer, the entire surface of a thick substrate such as a card made of vinyl chloride with a magnetic stripe, which is difficult to apply the thermosensitive layer, or the like. A part of information stored in the magnetism can be displayed.
The reversible thermosensitive recording label can be used as a substitute for a display label on a disk cartridge containing a rewritable disk such as a flexible disk (FD), MD, or DVD-RAM.

FIG. 6 shows an example in which the reversible thermosensitive recording label 10 of the present invention is affixed onto an MD disk cartridge 70. In this case, it is possible to apply to uses such as automatically changing the display contents in accordance with the change of the contents stored in the MD. In the case of a disc that does not use a disc cartridge such as a CD-RW, the reversible thermosensitive recording label of the present invention may be directly attached to the disc.
FIG. 7 shows an example in which the reversible thermosensitive recording label 10 of the present invention is affixed on the CD-RW 71. In this case, the reversible thermosensitive recording label can be pasted on a write-once disc such as CR-R instead of CD-RW, and a part of the stored information added to the CD-R can be rewritten and displayed. It is.

  FIG. 8 shows an example in which the reversible thermosensitive recording label of the present invention is pasted on an optical information recording medium (CD-RW) using an AgInSbTe phase change memory material. The basic configuration of this CD-RW is that a first dielectric layer 110, an optical information storage layer 109, a second dielectric layer 108, a reflective heat dissipation layer 107, and an intermediate layer 106 are formed on a base 111 having a guide groove. The hard coat layer 112 is provided on the back surface of the substrate 111 in order. The reversible thermosensitive recording label 10 of the present invention is affixed on the CD-RW intermediate layer 106. The reversible thermosensitive recording label 10 includes an adhesive layer or an adhesive layer 105, a back layer 104, a support 103, a reversible thermosensitive layer 102, and a protective layer 101 in this order. The dielectric layer is not necessarily provided on both sides of the optical information storage layer, but the first dielectric layer 110 may be provided when the substrate is made of a material having low heat resistance such as polycarbonate resin. desirable.

  FIG. 9 shows an example in which the reversible thermosensitive recording label 10 of the present invention is stuck on the video cassette 72. In this case, the display content can be automatically changed according to the change in the content stored in the video tape cassette.

  As a method of providing the reversible thermosensitive recording function on a card, a disk, a disk cartridge, and a tape cassette, in addition to a method of applying the reversible thermosensitive recording label, a method of directly applying the thermosensitive layer on them, Examples include a method in which the heat-sensitive layer is formed on another support in advance and the heat-sensitive layer is transferred onto the card, the disk, the disk cartridge, and the tape cassette. In the case of the method for transferring the heat-sensitive layer, the adhesive layer such as a hot-melt type or the pressure-sensitive adhesive layer may be provided on the heat-sensitive layer. When the reversible thermosensitive recording label is affixed on a rigid object such as the card, the disc, the disc cartridge, and the tape cassette, or when the thermosensitive layer is provided, the contact with the thermal head is improved. In order to form an image uniformly, it is preferable that a layer or sheet serving as a cushion is provided between a rigid substrate and a label or the heat-sensitive layer.

In the reversible thermosensitive recording medium of the present invention, for example, as shown in FIG. 10, a thermosensitive layer 13, an intermediate layer 14, and a protective layer 15 are provided on a support 11, and a back layer 16 is provided on the back surface of the support 11. As shown in FIG. 11, the heat-sensitive layer 13 and the protective layer 15 are provided on the support 11, and the back layer 16 is provided on the back surface of the support 11. Can do.
The film (reversible thermosensitive recording medium) of each aspect can be suitably used for, for example, various sheet-like industrial rewritable sheets provided with the RF-ID tag 85 shown in FIG. Further, for example, as shown in FIG. 12A, it can be used as a form processed into a reversible thermosensitive recording card 21 having a print display unit 23. As shown in FIG. 12B, a magnetic recording portion is formed on the back side of the card, and a back layer 24 is formed on the magnetic recording portion.

  In addition, the reversible thermosensitive recording member (card) shown in FIG. 13A is formed on the support by processing a film provided with a thermosensitive layer and a protective layer into a card shape to form a depression 25 for accommodating an IC chip, It is processed into a card shape. In FIG. 13A, the rewrite recording unit 26 is labeled on a card-like reversible thermosensitive recording medium, and an IC chip embedding recess 25 is formed at a predetermined location on the back side of the card. As shown in FIG. 13B, the wafer 231 is assembled and fixed in the recess 25. In the wafer 231, an integrated circuit 233 is provided on a wafer substrate 232, and a plurality of contact terminals 234 that are electrically connected to the integrated circuit 233 are provided on the wafer substrate 232. The contact terminal 234 is exposed on the back side of the wafer substrate 232 and is configured such that a dedicated printer (reader / writer) can electrically contact the contact terminal 234 to read or rewrite predetermined information. Yes.

Next, the function of the reversible thermosensitive recording card will be described with reference to FIG. FIG. 14A is a schematic configuration block diagram showing the integrated circuit 233. FIG. 14B is a configuration block diagram illustrating an example of data stored in the RAM. The integrated circuit 233 is composed of, for example, an LSI, in which a CPU 235 capable of executing a control operation in a predetermined procedure, a ROM 236 for storing operation program data of the CPU 235, writing of necessary data, and the like. A RAM 237 capable of reading is included. Further, the integrated circuit 233 receives an input signal, gives input data to the CPU 235, receives an output signal from the CPU 235, and outputs it to the outside. Although not shown, a power-on reset circuit, A clock generation circuit, a pulse frequency division circuit (interrupt pulse generation circuit), and an address decoder circuit.
The CPU 235 can execute the operation of the interrupt control routine according to the interrupt pulse periodically given from the pulse frequency dividing circuit. The address decoding circuit decodes address data from the CPU 235 and provides signals to the ROM 236, the RAM 237, and the input / output interface 238, respectively. A plurality (eight in FIG. 14) of contact terminals 234 are connected to the input / output interface 238, and predetermined data from the dedicated printer (reader / writer) is transmitted from the contact terminals 234 via the input / output interface 238. Input to the CPU 235. The CPU 235 performs each operation in response to the input signal and according to the program data stored in the ROM 236, and outputs predetermined data and signals to the sheet reader / writer via the input / output interface 238.

  As illustrated in FIG. 14B, the RAM 237 includes a plurality of storage areas 239a to 239g. For example, the sheet number is stored in the area 239a. For example, the storage area 239b stores ID data such as the name, affiliation, and telephone number of the sheet manager. For example, the storage area 239c stores information on the remaining margin or handling that can be used by the user. For example, the storage area 239d, the storage area 239e, the storage area 239f, and the storage area 239g store information related to the previous manager, the previous user, and the like.

  There is no particular limitation on at least one of the reversible thermosensitive recording label and the reversible thermosensitive recording member of the present invention, and image processing can be performed by various image processing methods and image processing apparatuses. An image can be formed and erased suitably using an image processing apparatus.

(Image processing method and image processing apparatus)
The image processing apparatus of the present invention includes at least one of an image forming unit and an image erasing unit, and further includes other units selected as necessary, for example, a transport unit, a control unit, and the like.
In the image processing method of the present invention, the reversible thermosensitive recording medium of the present invention is heated to perform at least one of image formation and erasure, and other processes appropriately selected as necessary, for example, a transport process And a control process.

  The image processing method of the present invention can be preferably carried out by the image processing apparatus of the present invention, and at least one of image formation and image erasure by heating the reversible thermosensitive recording medium of the present invention is the image. It can be performed by at least one of a forming unit and an image erasing unit, and the other steps can be performed by the other units.

-Image forming means and image erasing means-
The image forming means is a means for forming an image by heating the reversible thermosensitive recording medium of the present invention. The image erasing means is means for erasing an image by heating the reversible thermosensitive recording medium of the present invention.
There is no restriction | limiting in particular as said image formation means, According to the objective, it can select suitably, For example, a thermal head, a laser, etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together.
The image erasing means is means for erasing an image by heating the reversible thermosensitive recording medium of the present invention. For example, a hot stamp, a ceramic heater, a heat roller, a heat block, hot air, a thermal head, a laser, etc. Irradiation apparatus etc. are mentioned. Among these, a ceramic heater is preferable. By using the ceramic heater, the apparatus can be miniaturized, a stable erased state can be obtained, and an image with good contrast can be obtained. There is no restriction | limiting in particular as preset temperature of the said ceramic heater, According to the objective, it can select suitably, For example, 110 degreeC or more is preferable, 112 degreeC or more is more preferable, and 115 degreeC or more is especially preferable.

By using the thermal head, the size can be further reduced, the power consumption can be reduced, and a battery-driven handy type device can also be realized. Also, a single thermal head can be used for recording and erasing the image. In this case, the size can be further reduced. When recording and erasing with one thermal head, once all the previous images are erased, a new image may be recorded again, or the energy is changed for each image and the previous image is erased at one time. An overwrite method for recording images is also possible. In the overwrite method, the time required for recording and erasing the image is reduced, leading to an increase in recording speed.
In the case of using a reversible thermosensitive recording member (card) having the thermosensitive layer and the information storage unit, the apparatus includes means for reading and rewriting the memory of the information storage unit.

  The transport means is not particularly limited as long as it has a function of sequentially transporting the reversible thermosensitive recording medium, and can be appropriately selected depending on the purpose. For example, the transport belt, the transport roller, the transport belt and the transport belt Combination with a roller, etc. are mentioned.

  The control means is not particularly limited as long as it has a function of controlling each step, and can control each step, and examples thereof include devices such as a sequencer and a computer.

  One mode for carrying out the image processing method of the present invention by the image processing apparatus of the present invention will be described with reference to FIGS. As shown in FIG. 15, the image processing apparatus 100 includes a heat roller 96, a thermal head 95, and a conveyance roller. In this image processing apparatus, the image recorded on the heat sensitive layer is heated and erased by the heat roller 96. Next, the processed new information is recorded on the heat sensitive layer by the thermal head 95.

When the reversible thermosensitive recording medium has an RF-ID tag, an RF-ID reader 99 is further provided as shown in FIGS. In this case, there is also an aspect of a parallel type image processing apparatus as shown in FIG.
As shown in FIGS. 16 and 17, in this image processing apparatus 100, first, the information of the RF-ID tag attached to the reversible thermosensitive recording medium is read by the RF-ID reader / writer 99, and the new information is read by RF. -After inputting the ID, the image recorded on the heat sensitive layer is erased by heating with the heat roller 96. Further, based on the information read and rewritten by the RF-ID reader / writer, the processed new information is recorded on the heat sensitive layer by the thermal head.
Other than the RF-ID reader / writer, a bar code reader, a magnetic head, or the like may be used. In the case of a barcode reader, after reading the barcode information already recorded on the thermal layer, the barcode and visualization information recorded on the thermal layer are erased by the heat roller, and the information read from the barcode is used as the basis. The newly processed information is recorded on the heat sensitive layer as a barcode and visualization information by the thermal head.
The image processing apparatus shown in FIG. 15 or 16 has a tray on which a reversible thermosensitive recording medium is stacked, and the medium is picked up one by one by a paper feeding method such as a friction pad method. The transported medium is transported by transport rollers and sent to the RF-ID reader / writer, where data is read and written. Furthermore, the reversible thermosensitive recording medium is conveyed by the conveying roller to the heat roller section which is an erasing unit, and the visualization information recorded on the reversible thermosensitive recording medium is erased. Then, it is conveyed to a thermal head unit and new information is recorded on a reversible thermosensitive recording medium. Thereafter, the reversible thermosensitive recording medium is conveyed by the conveying roller, and the reversible thermosensitive recording medium is unloaded from the upper paper discharge unit.
Here, it is desirable that the set temperature of the heat roller is set to match the erasing temperature of the reversible thermosensitive recording medium. For example, the heat roller surface temperature is preferably 100 ° C. or higher and 190 ° C. or lower, more preferably 110 ° C. or higher and 180 ° C. or lower, and still more preferably 115 ° C. or higher and 170 ° C. or lower.

Further description will be made with reference to FIG. The image processing apparatus shown in FIG. 18A includes a thermal head 53, a ceramic heater 38, a magnetic head 34, and transport rollers 31, 40, and 47 as the heat processing means.
As shown in FIG. 18A, in this image processing apparatus, first, information stored in the magnetic thermosensitive layer of the reversible thermosensitive recording medium is read by a magnetic head. Next, the image recorded on the heat sensitive layer is erased by heating with a ceramic heater. Furthermore, new processed information is recorded on the heat sensitive layer by the thermal head based on the information read by the magnetic head. Thereafter, the information of the magnetic thermosensitive layer is also rewritten with new information.
In the image processing apparatus shown in FIG. 18A, the reversible thermosensitive recording medium 1 provided with a magnetic thermosensitive layer on the opposite side of the thermosensitive layer is conveyed along a conveyance path indicated by a reciprocating arrow, or along the conveyance path. Then it is transported in the reverse direction. The reversible thermosensitive recording medium 1 is magnetically recorded or erased on the magnetic thermosensitive layer between the magnetic head 34 and the conveying roller 31, and is heat-treated for image erasing between the ceramic heater 38 and the conveying roller 40, and the thermal head 53 and the area conveying. An image is formed between the rollers 47. Then, it is carried out of the apparatus. As described above, the set temperature of the ceramic heater 38 is preferably 110 ° C. or higher, more preferably 112 ° C. or higher, and particularly preferably 115 ° C. or higher. However, the rewriting of the magnetic recording may be performed before or after the image erasure by the ceramic heater. If desired, after passing between the ceramic heater 38 and the transport roller 40 or after passing between the thermal head 53 and the transport roller 47, the transport path is transported in the reverse direction. A second heat treatment by the ceramic heater 38 and a second printing process by the thermal head 53 can be performed.

  In the image processing apparatus of FIG. 18B, the reversible thermosensitive recording medium 1 inserted from the entrance / exit 30 proceeds along the conveyance path 50 shown by the one-dot broken line, or reverses the inside of the apparatus along the conveyance path 50. Proceed in the direction. The reversible thermosensitive recording medium 1 inserted from the entrance / exit 30 is transported in the recording apparatus by a transport roller 31 and a guide roller 32. When the sensor 33 reaches a predetermined position in the transport path 50, its presence is recognized by the control means 34c via the control means 34c, and magnetic recording or recording is erased or recorded on the magnetic thermosensitive layer between the magnetic head 34 and the platen roller 35. Between the ceramic roller 38 and the platen roller 44, which passes between the conveying rollers 37, passes between the guide roller 39 and the conveying roller 40, and operates by recognizing its presence via the ceramic heater control means 38 c by the sensor 43. The image is heated for image erasing, is conveyed in the conveyance path 50 by conveyance rollers 45, 46 and 47, and is operated by recognizing its presence via the thermal head control means 53c by the sensor 51 at a predetermined position. An image is formed between the head 53 and the platen roller 52, and the conveyance roller 59 and the gas are conveyed from the conveyance path 56a. It is unloaded outside the apparatus through the outlet 61 by Dorora 60. Here, there is no restriction | limiting in particular as preset temperature of the ceramic heater 38, According to the objective, it can select suitably, As mentioned above, 110 degreeC or more is preferable, 112 degreeC or more is more preferable, 115 degreeC or more is preferable. Particularly preferred.

  If desired, reversible thermosensitive recording is performed by a conveyor belt 58 that is guided to the conveyor path 56b by switching the conveyor path switching means 55a and moves in the reverse direction by the operation of a limit switch 57a that is input by pressing the reversible thermosensitive recording medium 1. After the medium 1 is again heat-treated between the thermal head 53 and the platen roller 52, the medium 1 is conveyed in the forward direction via the conveying path 49b, the limit switch 57b, and the conveying belt 48 which are communicated by switching the conveying path switching means 55b. From 56a, it can be carried out of the apparatus through the outlet 61 by the conveying roller 59 and the guide roller 60. Further, such branched conveyance paths and conveyance switching means can be provided on both sides of the ceramic heater 38. In that case, it is desirable to provide the sensor 43 a between the platen roller 44 and the transport roller 45.

  According to the image processing apparatus and the image processing method of the present invention, since the reversible thermosensitive recording medium of the present invention having a good high-speed erasability in a wide environmental range from normal temperature and normal humidity to low temperature and low humidity, the color density is good. In addition, it is excellent in high-speed erasability and can perform rewriting recording with high practicality.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to the following Example at all.

( Reference Example 1 )
-Production of reversible thermosensitive recording medium-
(1) Support As a support, a 188 μm thick cloudy polyester film (Teijin DuPont, Tetron film U2L98W) was used.
(2) Formation of heat-sensitive layer 4 parts by mass of a developer represented by the following structural formula, 0.04 parts by mass of polyethylene glycol (number average molecular weight: 2,500), acrylic polyol resin (manufactured by Mitsubishi Rayon Co., Ltd., LR503, A composition comprising 9 parts by mass of a solid content concentration 50% by mass solution and 70 parts by mass of methyl ethyl ketone was pulverized and dispersed using a ball mill until the particle size became 1 to 4 μm.

To the obtained dispersion, 1 part by mass of 2-anilino-3-methyl-6-diethylaminofluorane and 2 parts by mass of an adduct type hexamethylene diisocyanate 75% by mass ethyl acetate solution (Nihon Polyurethane Co., Ltd., Colonnade HL) were added. The mixture was stirred well to prepare a heat-sensitive layer coating solution.
The obtained heat-sensitive layer coating solution was applied to the support using a wire bar, dried at 100 ° C. for 2 minutes, and then heated at 60 ° C. for 24 hours to form a heat-sensitive layer having a thickness of about 8.0 μm. Provided.

(3) Formation of intermediate layer 100 parts by mass of a 10% by weight methyl ethyl ketone (MEK) solution of polyester polyol resin (Takeda Pharmaceutical Co., Ltd., Takelac U-21), 10 parts by mass of zinc oxide (Sumitomo Osaka Cement Co., Ltd.), And 15 parts by mass of Coronate HL (manufactured by Nippon Polyurethane Co., Ltd.) were mixed to prepare an intermediate layer coating solution.
The obtained intermediate layer coating solution was applied onto the heat sensitive layer using a wire bar, dried at 90 ° C. for 1 minute, and then heated at 60 ° C. for 2 hours to form an intermediate layer having a thickness of about 2.0 μm. Was established.

(4) Formation of protective layer 10 parts by mass of urethane acrylate ultraviolet curable resin (C7-157, manufactured by Dainippon Ink Co., Ltd.), 1.5 parts by mass of silica (P-527, manufactured by Mizusawa Chemical Co., Ltd.), and acetic acid 90 parts by mass of ethyl was mixed to prepare a protective layer coating solution.
After coating the obtained protective layer coating solution on the intermediate layer using a wire bar, it is passed under an ultraviolet lamp with an irradiation energy of 80 W / cm at a conveying speed of 12 m / min and cured to protect the film to a thickness of 3 μm. A layer was provided.
Thus, the reversible thermosensitive recording medium of Reference Example 1 was produced.

( Reference Example 2 )
-Production of reversible thermosensitive recording medium-
In Reference Example 1 , reversible feeling was obtained in the same manner as in Reference Example 1 , except that 0.04 parts by mass of polyethylene glycol (number average molecular weight: 2,500) in the step of forming the thermosensitive layer was changed to 0.2 parts by mass. A thermal recording medium was produced.

(Example 3)
-Production of reversible thermosensitive recording medium-
In Reference Example 1 , except that 0.04 parts by mass of polyethylene glycol (number average molecular weight: 2,500) in the step of forming the thermosensitive layer was changed to 0.2 parts by mass of polyethylene glycol (number average molecular weight: 6,000). In the same manner as in Reference Example 1 , a reversible thermosensitive recording medium was produced.

(Example 4)
-Production of reversible thermosensitive recording medium-
In Reference Example 1 , except that 0.04 parts by mass of polyethylene glycol (number average molecular weight: 2,500) in the step of forming the thermosensitive layer was changed to 0.2 parts by mass of polyethylene glycol (number average molecular weight: 20,000). In the same manner as in Reference Example 1 , a reversible thermosensitive recording medium was produced.

(Example 5)
-Production of reversible thermosensitive recording medium-
In Reference Example 1 , except that 0.04 parts by mass of polyethylene glycol (number average molecular weight: 2,500) in the step of forming the thermosensitive layer was changed to 0.2 parts by mass of polyethylene glycol (number average molecular weight: 200,000). In the same manner as in Reference Example 1 , a reversible thermosensitive recording medium was produced.

(Example 6)
-Production of reversible thermosensitive recording medium-
In Reference Example 1 , 0.04 parts by mass of polyethylene glycol (number average molecular weight: 2,500) in the step of forming the thermosensitive layer was changed to 0.2 parts by mass of polyethylene glycol (number average molecular weight: 5,000,000). A reversible thermosensitive recording medium was produced in the same manner as in Reference Example 1 except for the above.

(Example 7)
-Production of reversible thermosensitive recording medium-
In Reference Example 1 , except that 0.04 parts by mass of polyethylene glycol (number average molecular weight: 2,500) in the step of forming the thermosensitive layer was changed to 0.2 parts by mass of polypropylene glycol (number average molecular weight: 10,000). In the same manner as in Reference Example 1 , a reversible thermosensitive recording medium was produced.

( Reference Example 8 )
-Production of reversible thermosensitive recording medium-
In Reference Example 1 , 0.04 parts by mass of polyethylene glycol (number average molecular weight: 2,500) in the heat-sensitive layer forming step was changed to 0.2 parts by mass of polytetramethylene glycol (number average molecular weight: 4,000). A reversible thermosensitive recording medium was produced in the same manner as in Reference Example 1 except for the above.

( Reference Example 9 )
-Production of reversible thermosensitive recording medium-
In Reference Example 1 , 0.04 parts by mass of polyethylene glycol (number average molecular weight: 2,500) in the thermosensitive layer forming step was changed to 0.2 parts by mass of polyethylene glycol monooleyl ether (number average molecular weight: 4,500). A reversible thermosensitive recording medium was produced in the same manner as in Reference Example 1 except for the above.

(Example 10)
-Production of reversible thermosensitive recording medium-
In Reference Example 1 , 0.04 parts by mass of polyethylene glycol (number average molecular weight: 2,500) in the step of forming the thermosensitive layer was changed to 0.2 parts by mass of polyethylene glycol monostearate (number average molecular weight: 6,000). A reversible thermosensitive recording medium was produced in the same manner as in Reference Example 1 except that the change was made.

Example 11
-Production of reversible thermosensitive recording medium-
In Reference Example 1 , 4 parts by mass of a developer represented by the following structural formula in the step of forming the heat-sensitive layer, 0.8 part by mass of a decolorization accelerator (C ₁₅ H ₃₃ CONHC ₁₈ H ₃₅ ), polyethylene glycol (number Using a ball mill, a composition comprising 0.1 part by weight of an average molecular weight (20,000), 9 parts by weight of an acrylic polyol resin (manufactured by Mitsubishi Rayon Co., Ltd., LR503, 50% by weight solid content solution), and 70 parts by weight of methyl ethyl ketone. A reversible thermosensitive recording medium was prepared in the same manner as in Reference Example 1 except that the particles were pulverized and dispersed until the particle size became 1 to 4 μm.

(Comparative Example 1)
-Production of reversible thermosensitive recording medium-
In Reference Example 1 , a reversible thermosensitive recording medium was produced in the same manner as in Reference Example 1 except that polyethylene glycol was not added in the thermosensitive layer forming step.

(Comparative Example 2)
-Production of reversible thermosensitive recording medium-
In Reference Example 1 , reversible thermosensitiveness was performed in the same manner as in Reference Example 1 , except that polyethylene glycol (number average molecular weight: 2,500) in the step of forming the thermosensitive layer was changed to polyethylene glycol (number average molecular weight: 600). A recording medium was produced.

(Comparative Example 3)
-Production of reversible thermosensitive recording medium-
In Reference Example 1 , a reversible feeling was obtained in the same manner as in Reference Example 1 , except that the polyethylene glycol (number average molecular weight: 2,500) in the step of forming the thermosensitive layer was changed to polypropylene glycol (number average molecular weight 3,500). A thermal recording medium was produced.

(Comparative Example 4)
-Production of reversible thermosensitive recording medium-
In Reference Example 1 , a reversible feeling was obtained in the same manner as in Reference Example 1 , except that polyethylene glycol (number average molecular weight: 2,500) in the thermosensitive layer forming step was changed to polyethylene (number average molecular weight: 5,000). A thermal recording medium was produced.

(Comparative Example 5)
-Production of reversible thermosensitive recording medium-
In Reference Example 1 , reversible in the same manner as in Reference Example 1 , except that polyethylene glycol (number average molecular weight: 2,500) in the heat-sensitive layer forming step was changed to polycaprolactone (number average molecular weight: 10,000). A heat-sensitive recording medium was produced.

<Erase print test>
Each of the reversible thermosensitive recording media of Reference Examples 1 and 2, Examples 3 to 7, Reference Examples 8 and 9, Examples 10 and 11 and Comparative Examples 1 to 5 produced as described above was air temperature 23 ° C. and relative humidity. Using a thermal printing simulator (manufactured by Yashiro Seisakusho) in a 50% RH environment, printing is performed under conditions of a voltage of 18 V and a pulse width of 2 msec to produce a belt-like print sample, and the color density and background density are measured by Macbeth densitometer RD914. It measured using.
The obtained print sample was erased in increments of 0.5 V from voltage 6 V to 13.5 V under a pulse width of 6 msec, and the density was measured in the same manner. The lowest density was defined as the decolored density.
Next, the coloring and decoloring tests were conducted in the same manner in an environment with an air temperature of 5 ° C., a relative humidity of 30% RH, and an air temperature of −5 ° C. (relative humidity of 30 to 50% RH). Concentration was measured. The results are shown in Table 1.

From the results of Table 1, in Reference Examples 1 and 2, Examples 3 to 7, Reference Examples 8 and 9, and Examples 10 and 11, the heat-sensitive layer contains a polyalkylene glycol compound having a number average molecular weight of 2,000 or more. By doing so, the influence of humidity is reduced even in a low temperature and low humidity environment of 5 ° C.-30% RH compared with Comparative Examples 1 to 5 in which the heat-sensitive layer does not contain a polyalkylene glycol compound having a number average molecular weight of 2,000 or more. It can be seen that the erasability is improved. In particular, in Examples 3 to 7, Reference Examples 8 and 9, and Examples 10 and 11, it was confirmed that the erasability was improved even in a strong low temperature environment of −5 ° C.

  The reversible thermosensitive recording medium of the present invention is used for a prepaid card, a point card, a credit card or the like when processed into a card shape. A sheet size larger than the card size widens the printing range, and can be used for general documents, process management instructions, and the like. Therefore, the reversible thermosensitive recording medium of the present invention can be widely used for large screens and various displays such as entrance / exit tickets, frozen food containers, stickers for industrial products, various chemical containers, logistics management applications, manufacturing process management applications, etc. Can do.

FIG. 1 is a diagram showing color development / decoloration characteristics (color development / decoloration phenomenon) in the reversible thermosensitive recording medium of the present invention. FIG. 2 is a schematic diagram illustrating an example of an RF-ID tag. FIG. 3 is a schematic view showing a state in which an RF-ID tag is bonded to the back layer surface side of the reversible thermosensitive recording medium. FIG. 4 is a schematic view showing an example of an industrial rewritable sheet (reversible thermosensitive recording medium). FIG. 5 is a schematic view showing a method of using an industrial rewritable sheet (reversible thermosensitive recording medium). FIG. 6 is a schematic view showing an example of a state in which the reversible thermosensitive recording medium label of the present invention is stuck on an MD disk cartridge. FIG. 7 is a schematic view showing an example of a state in which the reversible thermosensitive recording medium label of the present invention is stuck on a CD-RW. FIG. 8 is a schematic cross-sectional view showing an example of a state in which the reversible thermosensitive recording medium label of the present invention is stuck on an optical information recording medium (CD-RW). FIG. 9 is a schematic view showing an example of a state in which the reversible thermosensitive recording medium label of the present invention is attached to a video cassette. FIG. 10 is a schematic sectional view showing an example of the layer structure of the reversible thermosensitive recording medium of the present invention. FIG. 11 is a schematic sectional view showing another example of the layer structure of the reversible thermosensitive recording medium of the present invention. FIG. 12A is a schematic view of the surface side of an example of the reversible thermosensitive recording medium of the present invention processed into a card shape. FIG. 12B is a schematic diagram of the back side of FIG. 12A. FIG. 13A is a schematic view of an example in which an example of the reversible thermosensitive recording medium of the present invention is processed into another card shape. FIG. 13B is a schematic view of an IC chip embedded in the IC chip recess of FIG. 13A. FIG. 14A is a schematic block diagram showing an integrated circuit. FIG. 14B is a schematic diagram showing that the RAM includes a plurality of storage areas. FIG. 15 is a schematic diagram showing an example of an image processing apparatus used in the image processing method of the present invention. FIG. 16 is a schematic diagram showing another example of an image processing apparatus used in the image processing method of the present invention. FIG. 17 is a schematic diagram showing still another example of the image processing apparatus used in the image processing method of the present invention. FIG. 18A is a schematic diagram of an image processing apparatus when a surface image is erased by a ceramic heater and an image is formed by a thermal head. FIG. 18B is a schematic diagram illustrating an example of the image processing apparatus of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Reversible thermosensitive recording medium 10 Reversible thermosensitive recording label 11 Support body 13 Heat sensitive layer 14 Intermediate layer 15 Protective layer 16 Back layer 22 Rewrite recording part 23 Print display part 24 Back layer 25 Depressed part 26 Rewrite recording part 30 Entrance / exit 31 Transport roller 32 guide roller 33 sensor 34 magnetic head 34c control means 35 platen roller 36 guide roller 37 transport roller 38 ceramic heater 38c ceramic heater control means 39 guide roller 40 transport roller 43 sensor 43a sensor 44 platen roller 45 transport roller 46 transport roller 47 transport roller 48 transport belt 49b transport path 50 transport path 51 sensor 52 platen roller 53 thermal head 53c thermal head control means 55a transport path switching means 55b transport path switching means 56a Sending passage 56b conveyance path 57a limit switch 57b limit switch 58 the conveyor belt 59 conveying roller 60 guide rollers 61 the outlet 70 MD disk cartridge 71 CD-RW
72 Video cassette 81 IC chip 82 Antenna 85 RF-ID tag 90 Industrial rewritable sheet (reversible thermosensitive recording member)
94 Ceramic heater 95 Thermal head 96 Heat roller 97 Paper feed tray 98 Reversible thermosensitive recording medium (rewritable sheet)
99 RF-ID reader / writer 100 Image processing apparatus 101 Protective layer 102 Thermal layer 103 Support body 104 Back layer 105 Adhesive layer or adhesive layer 106 Intermediate layer 107 Reflective heat dissipation layer 108 Second dielectric layer 109 Optical information storage layer 110 First 1 dielectric layer 111 substrate 112 hard coat layer 231 wafer 232 wafer substrate 233 integrated circuit 234 contact terminal 235 CPU
236 ROM
237 RAM
238 I / O interface 239a to 239g Storage area

Claims (18)

A polyalkylene glycol having at least a support and a heat-sensitive layer whose color tone reversibly changes depending on temperature on the support, the heat-sensitive layer having a number average molecular weight of 6,000 to 6,000,000 Containing a compound,
The reversible thermosensitive recording medium, wherein the thermosensitive layer contains an electron donating color-forming compound and an electron accepting compound.   The reversible thermosensitive recording medium according to claim 1, wherein the number average molecular weight of the polyalkylene glycol compound is 15,000 to 6,000,000.   The reversible thermosensitive recording medium according to claim 1, wherein the polyalkylene glycol compound is a polyethylene glycol compound.   The reversible thermosensitive recording medium according to any one of claims 1 to 3, wherein one end of the polyalkylene glycol compound is substituted with any of an ether group, an ester group and a urethane group.   The reversible thermosensitive recording medium according to any one of claims 1 to 4, wherein a content of the polyalkylene glycol compound in the thermosensitive layer is 0.1 to 50 parts by mass with respect to 100 parts by mass of the resin component. 6. The reversible thermosensitive recording medium according to claim 1, wherein the electron accepting compound is a phenol compound represented by the following general formula (1).
However, in said general formula (1), n represents the integer of 1-3. X represents a divalent group containing a nitrogen atom or an oxygen atom. R ¹ and ^{R 2,} to display the aliphatic hydrocarbon group.   The reversible thermosensitive recording medium according to claim 6, wherein X in the general formula (1) is a urea group.   The heat-sensitive layer contains a decolorization accelerator, and the decolorization accelerator is a compound having at least one of an amide group, a urethane group, and a urea group in the molecule. Reversible thermosensitive recording medium.   The reversible thermosensitive recording medium according to any one of claims 1 to 8, wherein the thermosensitive layer contains a resin in a crosslinked state.   The reversible thermosensitive recording medium according to any one of claims 1 to 9, wherein the reversible thermosensitive recording medium is processed into a card shape, a label shape, or a sheet shape.   11. A reversible thermosensitive recording comprising an adhesive layer or a pressure-sensitive adhesive layer on a surface opposite to a surface on which an image is formed in the reversible thermosensitive recording medium according to any one of claims 1 to 10. label.   A reversible thermosensitive recording member comprising an information storage unit and a reversible display unit, wherein the reversible display unit includes the reversible thermosensitive recording medium according to any one of claims 1 to 11.   The reversible thermosensitive recording member according to claim 12, wherein the information storage unit and the reversible display unit are integrated.   The reversible thermosensitive recording member according to any one of claims 12 to 13, wherein the information recording unit is selected from a magnetic thermosensitive layer, a magnetic stripe, an IC memory, an optical memory, an RF-ID tag card, a disk, a disk cartridge, and a tape cassette. . At least forming an image on the reversible thermosensitive recording medium by heating the reversible thermosensitive recording medium, and erasing the image formed on the reversible thermosensitive recording medium by heating the reversible thermosensitive recording medium. An image processing method comprising: the reversible thermosensitive recording medium according to claim 1, wherein the reversible thermosensitive recording medium is the reversible thermosensitive recording medium according to claim 1. The image processing method according to claim 15, wherein the image is formed using either a thermal head or a laser irradiation device. The image processing method according to any one of claims 15 to 16, wherein the image is erased using any one selected from a thermal head, a ceramic heater, a heat roll, a hot stamp, a heat block, and a laser irradiation apparatus. The image processing method according to claim 15, wherein a new image is formed while erasing the image using a thermal head.