JP3326693B2 - Card with thermal display - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a card with a heat-sensitive display, and more particularly to a card having a display function, particularly cards which are also effective as an IC card.

[0002]

2. Description of the Related Art A wide variety of "cards" such as prepaid cards and credit cards have appeared on the market and have already penetrated society. Many of these cards recorded information magnetically, so the amount of information was small and the range of use was limited due to the fact that they were easily falsified. It has also made it possible to use cards that allow many services such as banks, transportation, and others.

[0003]

2. Description of the Related Art It is desired to provide a rewritable display unit on an IC card or the like, similarly to other cards.

The performance of a display unit for an IC card requires that power consumption during operation is small, and that, in particular, in order to maintain display, almost no power is consumed. This is because the capacity of the power supply unit of the IC card itself is small, and an operation of consuming a large amount of power is possible only when the IC card is connected to the card terminal device.

The next required performance is high repetition durability of display rewriting. This has a wider use range and a longer useful life than conventional cards, and therefore naturally has a large number of rewrites.

[0006] For example, a liquid crystal display is excellent in repeated durability, but power must be constantly consumed to maintain the display. Also, in the method of rewriting with a thermal head using a reversible thermosensitive recording material, power is not required during display, so it can be said that the power consumption is low, but the repetitive durability of the thermosensitive recording material due to rewriting is insufficient. I have.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a card with a heat-sensitive display, which is provided with a display unit having high repetition durability of rewriting and low power consumption, and particularly useful for an IC card. That is.

[0008]

According to the present invention, there is provided a card with a thermosensitive display, which is formed by providing a layer of a reversible thermosensitive recording material on or between resistive heating elements in which the thermosensitive display portions are two-dimensionally arranged. An electrode for supplying current to the resistance heating element is a light reflection layer;
And the display can be rewritten.

The present inventors have proposed a display device in which a resistive heating element is arranged two-dimensionally and a reversible thermosensitive recording material is integrated therewith (JP-A-1-177586, JP-A-2-87, etc.). Gazette: Applicant (Ricoh Co., Ltd.)
This display device has a feature that a full-color, high-resolution dot matrix image can be obtained. Initially, this display device was intended for a large area flat display or projection type display, but it was difficult to process large area electrodes, and the screen response speed was inferior to liquid crystal displays. It has been found that practical application is difficult for the following reasons. I have been searching for alternative uses, but have not found it. However, it has recently been found that the repetition durability of image rewriting by this display device is several tens times or more higher than that of a thermal head. As a result, they have found that they are most suitable for a display device for an IC card due to their two features of high repetition durability and low power consumption, and have reached the present invention.

Hereinafter, the present invention will be described in more detail. Now, when the repetition durability of rewriting by the thermal head is compared with the repetition durability of rewriting of the display device of the present invention, the latter is superior by orders of magnitude. Although the cause has not been determined yet, it is presumed as follows at present.

When rewriting with a thermal head,
The reversible thermosensitive recording material rubs against the thermal head. Since the heated reversible thermosensitive recording material is very soft, it is easily deformed by the stress caused by friction with the thermal head, and the structure of the material changes. It is considered that the result of the accumulation of these changes appears as deterioration of the reversible thermosensitive recording material. On the other hand, in the configuration in which the layer of the reversible thermosensitive recording material is provided on the heating element, the reversible thermosensitive recording material is fixed to the heating element, so that it does not rub and does not deteriorate. It seems to be.

The structure of the card with a heat-sensitive display in the present invention is basically similar in concept to the two display devices proposed by the present inventors, but is used for an IC card or the like. In order to do so, the following two points need to be considered. 1. To reduce the thickness of the entire display unit 2. To prevent the heat of the heating element from being transmitted to the IC chip and surrounding resin parts. By providing a reflective layer, high contrast can be obtained with a thin recording layer. -The role of the reflection layer also serves as an electrode that supplies power to the heating element.・ Provide a heat insulation layer under the heating element. Etc. are effective. 1 and 2 are conceivable as specific representative configurations. Actually, one or more of these configurations are combined. 1 and 2, 1 is a resistance heating layer, 21 is a metal electrode, 2
Reference numeral 2 denotes an electrode, 23 denotes a transparent electrode, 3 denotes a reversible thermosensitive recording material layer, 4 denotes a polyester film, 5 denotes a protective layer, and 6 denotes a resistance heating layer and a reversible thermosensitive recording material.

Since the heat resistance of the resistance heating element 1 is not required to be as high as that of a thermal head, a metal having a relatively high electric resistance is formed into a thin film by sputtering or the like, and a conductive polymer or resin is used to form conductive particles. Can be used. The use of a resin is effective in increasing the heat insulation. Among them, a thermosetting resin and a thermoplastic resin having good heat resistance are preferable, and specifically, DFK resin, epoxy resin, vinyl ester resin, phenol resin, unsaturated polyester resin, furan resin, polyimide, poly-P-hydroxybenzoic acid , Polyurethane, maleic acid resin, melamine resin, thermosetting resin such as urea resin and ionomer resin, isobutylene-maleic anhydride copolymer resin,
AAS resin, AES resin, ABS resin, ACS resin, M
BS resin, ethylene-vinyl chloride copolymer resin, ethylene-vinyl acetate copolymer resin, vinylidene chloride resin, vinyl chloride resin, chlorinated vinyl chloride resin, chlorinated polyethylene, chlorinated polypropylene, cumarone resin, ketone resin, vinyl acetate resin , Phenoxy resin, butadiene resin, fluororesin, vinyl propionate resin, polyacetal, polyamide, polyamideimide, polyarylate, thermoplastic polyimide, polyetherimide, polyetheretherketone, polyethylene, polyethylene oxide, polyethylene terephthalate, polycarbonate, polystyrene, Polysulfone, poly-P-methylstyrene, polyvinyl alcohol, polyvinyl ether, polyvinyl butyral, polyvinyl formal, polybutylene terephthalate, Polypropylene, polymethylpentene, and methacrylic resin can be used. The volume resistance value of these heating element materials is 0.01 to 100Ω.
cm or so, more preferably 0.5 to 20 Ωc
m is good.

The material of the electrodes 21, 22 or 23 of the resistance heating element
The following materials are preferably used. Electrode 21
The material is a metal material such as aluminum to serve as the radiation layer
It is preferable that the electrode 22 be made of a metal material such as aluminum, a transparent conductive material such as ITO, a conductive polymer, a conductive resin composition, or the like. Further, the material of the electrode 23
The material is excellent in a transparent material such as ITO. In addition, conductive polymers and conductive resin compositions are excellent in terms of ease of production.

The reversible thermosensitive recording material layer 3 in the present invention
Is made of a material that causes a reversible visual change due to a temperature change. Visible changes can be divided into color changes and shape changes, and the present invention mainly uses materials that cause color changes. Changes in color tone include changes in transmittance, reflectance, absorption wavelength, scattering degree, and the like, and an actual reversible thermosensitive recording material performs display by a combination of these changes. More specifically, (a) a material that changes reversibly between a transparent state and a cloudy state. (B) Materials such as dyes that change color reversibly. At present, they can be classified into two types. As described in the prior art, (a) is a typical example in which a heat-sensitive layer in which organic low-molecular substances such as higher alcohols and higher fatty acids are dispersed in a resin base material such as polyester is provided. (B) is a conventional leuco reversible recording material (for example, JP-A-1-188293, JP-A-1-18893).
No. 88294).

The "transparent and cloudy opaque state" in the "material composed of a resin matrix and an organic low-molecular substance dispersed in the resin matrix and reversibly changing the state of transparency and cloudiness by heating" is used. The difference is speculated as follows. That is, in the case of (I) transparent, the particles of the organic low-molecular substance dispersed in the resin base material are composed of large particles of the organic low-molecular substance, and the light incident from one side is not scattered and is opposite. (II) In the case of white turbidity, the particles of the organic low molecular weight substance are composed of polycrystals in which fine crystals of the organic low molecular weight substance are aggregated, and the crystal axis of each crystal Is oriented in various directions, so that light incident from one side is refracted many times at the interface between the crystals of the organic low-molecular substance particles, and is scattered, so that it appears white.

In FIG. 5 (representing a change in transparency due to heat), a heat-sensitive layer mainly composed of a resin base material and an organic low-molecular substance dispersed in the resin base material has a temperature of, for example, T ₀ or less. At room temperature, it is cloudy and opaque. This became clear when heated to a temperature T _2, which remains also clear again returned to the normal temperature of T ₀ or less in this state. This may be because the crystalline low-molecular organic material before reaching the T ₀ or less from the temperature T ₂ is between the single crystal from a polycrystalline via a semi-molten state grows. Upon further heating to T ₃ or more temperature becomes translucent state intermediate between the maximum transparency and the maximum opacity. Next, when the temperature is lowered, the state returns to the original cloudy and opaque state without taking the transparent state again. This after low-molecular organic material is melted at a temperature T ₃ or more,
It is considered that polycrystals are precipitated by cooling. When this opaque state is heated to a temperature between T _{1 and} T ₂ and then cooled to room temperature, that is, a temperature equal to or lower than T ₀ , an intermediate state between transparent and opaque can be obtained.
Also, by returning to room temperature After heating to be again T ₃ or more temperature which became clear at the normal temperature, the flow returns to cloudy opaque state again. That is, both opaque and transparent forms at room temperature and intermediate states thereof can be taken.

Therefore, the heat-sensitive layer can be selectively heated by selectively applying heat to form a cloudy image on a transparent ground and a transparent image on a cloudy ground, and the change can be repeated many times. It is possible. If a colored sheet is arranged on the back of such a heat-sensitive layer, a color image of the colored sheet on a white background or a white image on a colored background of the colored sheet can be formed. Further, when projected by an OHP (overhead projector) or the like, the cloudy portion becomes a dark portion, the transparent portion transmits light, and becomes a bright portion on the screen.

In order to prepare the reversible thermosensitive recording material (a) according to the present invention, generally, (1) a solution in which two components of a resin base material and an organic low-molecular substance are dissolved, or (2) a solution of the resin base material (Use a solvent that does not dissolve at least one of the organic low-molecular substances as the solvent) and apply a dispersion of the organic low-molecular substances dispersed in fine particles on a support such as a plastic film, a glass plate, or a metal plate. What is necessary is just to dry and form a heat-sensitive layer.

The solvent for forming the heat-sensitive layer or the heat-sensitive recording material can be variously selected depending on the type of the resin base material and the organic low-molecular substance. For example, tetrahydrofuran, methyl ethyl ketone, methyl isobutyl ketone, chloroform, carbon tetrachloride, ethanol, toluene, Benzene and the like can be mentioned. In addition, of course, when a dispersion is used,
Even when a solution is used, in the heat-sensitive layer obtained, the organic low-molecular substance is precipitated as fine particles and exists in a dispersed state.

The resin base material used for the heat-sensitive layer is a material that forms a layer in which organic low-molecular substances are uniformly dispersed and held, and that affects the transparency at the time of maximum transparency. For this reason, the resin base material is preferably a resin having good transparency, mechanical stability, and good film formability.

Examples of such resins include polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-vinyl alcohol copolymer, vinyl chloride-vinyl acetate-maleic acid copolymer, and vinyl chloride-vinyl chloride. Vinyl chloride copolymers such as acrylate copolymers; polyvinylidene chloride, vinylidene chloride-vinyl chloride copolymer, vinylidene chloride copolymers such as vinylidene chloride-acrylonitrile copolymer; polyester; polyamide; polyacrylate or poly Methacrylate or acrylate-methacrylate copolymer; silicone resin, and the like. These may be used alone or as a mixture of two or more.

On the other hand, any organic low-molecular substance may be used as long as it changes from polycrystal to single crystal by heat in the recording layer, and a substance having a melting point of about 30 to 200 ° C., preferably about 50 to 150 ° C. is generally used. . Such organic low molecular weight substances include alkanol; alkane diol; halogen alkanol or halogen alkane diol; alkylamine; alkane; alkene; alkyne; halogen alkane; halogen alkene; halogen alkyne; cycloalkane; cycloalkene; cycloalkyne; Unsaturated mono- or dicarboxylic acids or their esters, amides or ammonium salts; saturated or unsaturated halogen fatty acids or their esters, amides or ammonium salts; allylcarboxylic acids or their esters, amides or ammonium salts; Esters, amides or ammonium salts thereof; thioalcohols; thiocarboxylic acids or their esters, amines or ammonium salts; Carboxylic acid esters, and the like. These may be used alone or in combination of two or more. The carbon number of these compounds is 10 to 60, preferably 10 to 38, particularly preferably 10 to 30. The alcohol group in the ester may be saturated or non-saturated, and may be halogen-substituted. In any case, the organic low-molecular substance is at least one kind of oxygen, nitrogen, sulfur and halogen in the molecule, for example, -OH, -COOH, -CONH
-, - COOR, -NH -, - NH 2, -S -, - SS -, - O-, is preferably a compound containing a halogen and the like.

More specifically, these compounds include
Uric acid, dodecanoic acid, myristic acid, pentadecane
Acid, palmitic acid, stearic acid, behenic acid, nonadeca
Higher fatty acids such as acid, araginic and oleic acid; stearic acid
Methyl phosphate, tetradecyl stearate, stearin
Octadecyl acid, octadecyl laurate, palmitin
Of higher fatty acids such as tetradecyl acrylate and dodecyl behenate
Stele; C₁₆H₃₃-O-C₁₆H₃₃ , C₁₆H₃₃-S-C₁₆H₃₃ , C₁₈H₃₇-S-C₁₈H₃₇ , C₁₂H_{twenty five}-S-C₁₂H_{twenty five} , C₁₉H₃₉-S-C₁₉H₃₉ , C₁₂H_{twenty five}-S-S-C₁₂H_{twenty five} ,    And ether or thioether. In particular, the present invention
Higher fatty acids, especially palmitic acid, stearic acid,
Higher fatty acids having 16 or more carbon atoms such as henic acid and lignoceric acid
Are preferred, and higher fatty acids having 16 to 24 carbon atoms are more preferred.
No.

In order to widen the range of temperatures at which transparency can be obtained, the organic low-molecular substance described in this specification may be appropriately combined, or such an organic low-molecular substance may be combined with another material having a different melting point. . These are disclosed, for example, in JP-A-63-3
No. 9378, JP-A-63-130380 and Japanese Patent Application No. 63-14
No. 754, Japanese Patent Application No. 1-140109, and the like, but are not limited thereto. The ratio between the organic low-molecular substance and the resin base material in the heat-sensitive layer was 2: 2 by weight.
About 1 to 1:16 is preferable, and 1: 1 to 1: 3 is more preferable. When the ratio of the resin base material is less than this, it becomes difficult to form a film holding the organic low-molecular substance in the resin base material. Becomes difficult.

In addition to the above components, additives such as a surfactant and a high boiling point solvent can be added to the heat-sensitive layer in order to facilitate formation of a transparent image. Specific examples of these additives are as follows. Examples of high boiling solvents: tributyl phosphate, tri-2-ethylhexyl phosphate, triphenyl phosphate, tricresyl phosphate, butyl oleate, dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diheptyl phthalate, diphthalic phthalate -n-octyl, di-2-ethylhexyl phthalate, diisononyl phthalate, dioctyldecyl phthalate, diisodecyl phthalate, butylbenzyl phthalate, dibutyl adipate, di-n-hexyl adipate, di-adipate
2-ethylhexyl, di-2-ethylhexyl azelate, dibutyl sebacate, di-2-ethylhexyl sebacate, diethylene glycol dibenzoate, triethylene glycol di-2-ethyl butyrate, methyl acetyl ricinoleate, butyl acetyl ricinoleate, butyl Phthalyl butyl glycolate, tributyl acetyl citrate.

Examples of surfactants and other additives; polyhydric alcohol higher fatty acid esters; polyhydric alcohol higher alkyl ethers; polyhydric alcohol higher fatty acid esters, higher alcohols, higher alkyl phenols, higher fatty acid higher alkyl amines, higher fatty acid amides Lower olefin oxide adducts of fats and oils or polypropylene glycol; acetylene glycol; Na, Ca, Ba or Mg salts of higher alkylbenzene sulfonic acids; higher fatty acids, aromatic carboxylic acids, higher fatty acid sulfonic acids, aromatic sulfonic acids, sulfuric acid monoesters Or phosphoric acid mono- or di-ester Ca,
Ba or Mg salt; low sulfated oil; poly long chain alkyl acrylate; acrylic oligomer; poly long chain alkyl methacrylate; long chain alkyl methacrylate-amine-containing monomer copolymer; styrene-maleic anhydride copolymer;
Olefin-maleic anhydride copolymer.

When an image of this recording material is used as a reflection image, providing a light reflecting layer on the back surface of the recording layer can increase the contrast even if the thickness of the recording layer is reduced. Specific examples include vapor deposition of Al, Ni, Sn and the like (described in JP-A-64-14079).

A protective layer can be provided on the heat-sensitive layer to protect the heat-sensitive layer. Examples of the material of the protective layer (thickness: 0.1 to 5 μm) laminated on the heat-sensitive layer include silicone rubber, silicone resin (described in JP-A-63-221087), and polysiloxane graft polymer (Japanese Patent Application No. 62-15255).
No. 0) or UV curable resin or electron beam curable resin
(Described in the specification of Japanese Patent Application No. 63-310600). In any case, a solvent is used at the time of application, but the solvent is
It is desirable that the resin of the heat-sensitive layer and the organic low-molecular substance are hardly dissolved. N-hexane, methyl alcohol,
Ethyl alcohol, isopropyl alcohol and the like can be mentioned, and an alcohol-based solvent is particularly desirable in terms of cost.

Further, an intermediate layer can be provided between the protective layer and the heat-sensitive layer in order to protect the heat-sensitive layer from the solvent and the monomer component of the protective layer forming solution (see JP-A-1-33781). Described). As the material of the intermediate layer, in addition to those listed as the resin base material in the thermosensitive layer, the following thermosetting resin,
Thermoplastic resins can be used. That is, polyethylene,
Examples include polypropylene, polystyrene, polyvinyl alcohol, polyvinyl butyral, polyurethane, saturated polyester, unsaturated polyester, epoxy resin, phenol resin, polycarbonate, and polyamide. The thickness of the intermediate layer is preferably about 0.1 to 2 μm.

Subsequently, the reversible thermosensitive recording layer is formed by the reversible thermochromic composition utilizing the color-forming reaction between the electron-donating color-forming compound and the electron-accepting compound described in (b) above. Will be described. A thermochromic composition utilizing a color-forming reaction between an electron-donating color-forming compound and an electron-accepting compound is non-conductive when the electron-donating color-forming compound and the electron-accepting compound are melted by heating. When the amorphous color former is heated at a temperature lower than the melting temperature, the electron-accepting compound undergoes crystallization and the color former decolorizes. is there.

The thermochromic composition develops color instantaneously by heating, and its coloration state is stably present even at room temperature, while the composition in the coloration state is instantly heated by heating below the coloration temperature. The color is erased, and the erased state is stably present even at room temperature, and such a reversible peculiar coloring / erasing behavior is a novel and surprising phenomenon that has not been seen before.

The principle of color development and decoloration when this composition is used as a heat-sensitive layer, that is, the principle of image formation and image erasure will be described with reference to the graph shown in FIG. The vertical axis of the graph represents the color density and the horizontal axis represents the temperature. The solid line 11 shows the image forming process by heating, and the broken line 13 shows the image erasing process by heating. A is a density in a completely erased state, B is a density in a completely colored state when heated to a temperature of t ₁ or more, C is a density in a completely colored state at a temperature of t ₀ or less, and D is t _0. shows the concentration when heated and erased with a temperature between ~t _1.

The composition according to the invention is in a colorless state (A) at temperatures below t ₀ . To perform recording to form a recorded image by color (B) by heating to t ₁ or higher. This recorded image is t according to the solid line 12.
_{Even when} the temperature is returned to ₀ or lower, the state (C) is maintained as it is, and the memory property of the recording is not lost.

Next, in order to erase the recorded image, the formed recorded image is brought to a colorless state (D) by heating it to a temperature between t _{0 and} t ₁ lower than the coloring temperature. This state maintains the colorless state (A) as it is even when the temperature is returned to the temperature of t ₀ or less. That is, the process of forming the recorded image reaches C along the path indicated by the solid line ABC, and the recording is held. Next, in the process of erasing the recorded image, the process proceeds to A along the path indicated by the broken line CDA, and the erased state is maintained. The behavior characteristics of forming and erasing the recorded image are reversible and can be repeated many times.

The reversible thermochromic composition here comprises a color former and a color developer as essential components. A color-forming state is formed by heating and melting the color-forming agent and the developer, while the color-forming state is erased by heating at a temperature lower than the color-forming temperature, and the color-forming state and the decolored state are stably present at room temperature. It is. The mechanism of such coloring and decoloring in the composition is that when the color former and the developer are heated and melt mixed at the color development temperature, the composition undergoes amorphization to form a color development state, while the color development temperature is increased. This is based on the property that when heated at a lower temperature, the color developer of the colored composition undergoes crystallization to form an erased state of color development.

A composition comprising an ordinary color former and a developer, for example, a leuco compound having a lactone ring, which is a dye precursor widely used in conventional thermal recording paper, and a phenolic compound exhibiting a color developing effect. When this is melted and mixed by heating, a color development state based on ring opening of the lactone ring of the leuco compound is obtained. This colored state is an amorphous state in which both are compatible. This colored amorphous state exists stably at room temperature, but does not crystallize when heated again, and there is no separation of the phenolic compound from the leuco compound, so there is no ring closure of the lactone ring and decolorization. Do not.

On the other hand, when the composition of the color former and the color developer according to the present invention is melted and mixed by heating, it becomes a color-developed state, exhibits an amorphous state as in the conventional case, and is stable at room temperature. Exists. However, in the case of the present invention, when the color-formed amorphous composition is heated at a temperature lower than the color-forming temperature, that is, at a temperature that does not reach the molten state, crystallization of the color developer occurs, and the composition is compatible with the color-forming agent. The bond due to the state cannot be maintained, and the color developer is separated from the color former. It is considered that due to the separation of the color developer from the color developer due to crystallization, the color developer cannot accept electrons from the color developer and the color developer loses its color.

The above-mentioned specific coloring / decoloring behavior observed in the thermochromic composition includes the phase mutual solubility of the coloring agent and the developing agent by heating and melting, the strength of the action of both in the coloring state, and the coloring. The solubility of the agent in the color former, the crystallinity of the developer, etc. are related, but in principle, it becomes amorphous by heating and melting, while it crystallizes by heating at a temperature lower than the coloring temperature. Any color developing agent / developing agent system that can be used as a composition component in the present invention. Further, those having such characteristics show endothermic changes due to melting and exothermic changes due to crystallization in thermal analysis. Therefore, the color former / developer system applicable to the present invention can be easily analyzed by thermal analysis. Can be confirmed. In addition, the reversible thermochromic composition system according to the present invention may include a third substance, for example, the reversible decoloring behavior is maintained even when a polymer substance is present. Was confirmed.

In the thermochromic composition of the present invention, the decoloration is caused by separation of the color developer from the color former by crystallization. The choice is important.

The following are examples of the developers preferably used in the present invention. As described above, the developers applicable to the present invention can be easily found by thermal analysis. It should be clear that this is not a limitation. (1) An organic phosphoric acid compound represented by the following general formula (1): R ₁ -PO (OH) ₂ (1) (where R ₁ is a linear or branched alkyl group or alkenyl having 8 to 30 carbon atoms) Specific examples of this organic phosphoric acid compound include the following. Octylphosphonic acid, nonylphosphonic acid, decylphosphonic acid, dodecylphosphonic acid, tetradecylphosphonic acid, hexadecylphosphonic acid, octadecylphosphonic acid, eicosylphosphonic acid, docosylphosphonic acid, tetracosylphosphonic acid.

(2) An organic acid having a hydroxyl group at the carbon at the α-position represented by the following general formula (2): R ₂ —CH (OH) COOH (2) (where R ₂ is a straight chain having 6 to 28 carbon atoms) Specific examples of the organic acid having a hydroxyl group at the carbon at the α-position include the following. α-hydroxyoctanoic acid, α-hydroxydodecanoic acid, α-hydroxytetradecanoic acid, α-hydroxyhexadecanoic acid, α-hydroxyoctadecanoic acid, α-hydroxypentadecanoic Acid, α-hydroxyeicosanoic acid, α-hydroxydocosanoic acid and the like.

The color former used in the present invention is a compound having an electron-accepting property and is itself a colorless or light-colored dye precursor, and is not particularly limited, and may be a conventionally known one such as triphenylmethanephthalide. Compounds, fluoran compounds, phenothiazine compounds, leuco auramine compounds, rhodamine lactam compounds, spiropyran compounds, indolinophthalide compounds, and the like. Specific examples include the following. 3,3-bis (p-dimethylaminophenyl) -phthalide, 3,3-
Bis (p-dimethylaminophenyl) -6-dimethylaminophthalide (also known as crystal violet lactone), 3,3-bis (p-dimethylaminophenyl)-
6-diethylaminophthalide, 3,3-bis (p-dimethylaminophenyl) -6-chlorophthalide, 3,3-
Bis (p-dibutylaminophenyl) phthalide, 3-cyclohexylamino-6-chlorofluoran, 3-dimethylamino-5,7-dimethylfluoran, 3-diethylamino-7-chlorofluorane, 3-diethylamino-7- Methylfluoran, 3-diethylamino-7,8
-Benzfluorane, 3-diethylamino-6-methyl-7-chlorofluorane, 3- (Np-tolyl-N-
Ethylamino) -6-methyl-7-anilinofluoran, 3-pyrrolidino-6-methyl-7-anilinofluoran, 2- {N- (3'-trifluoromethylphenyl) amino} -6-diethylamino Fluoran, 2-
{3,6-bis (diethylamino) -6- (o-chloroanilino) xanthyl lactam lactam}, 3-diethylamino-6-methyl-7- (m-trichloromethylanilino) fluoran, 3-diethylamino-7- ( o-
Chloranilino) fluoran, 3-dibutylamino-7
-(O-chloroanilino) fluoran, 3-N-methyl-N-amylamino-6-methyl-7-anilinofluoran, 3-N-methyl-N-cyclohexylamino-6
-Methyl-7-anilinofluoran, 3-diethylamino-6-methyl-7-anilinofluoran, 3- (N,
N-diethylamino) -5-methyl-7- (N, N-dibenzylamino) fluoran, benzoleucomethylene blue, 6'-chloro-8'-methoxy-benzoindolino-spiropyran, 6'-bromo-2'- Methoxy-benzoindolino-spiropyran, 3- (2'-hydroxy-4'-dimethylaminophenyl) -3- (2'methoxy-5'-chlorophenyl) phthalide, 3- (2'hydroxy-4'-dimethyl Aminophenyl) -3-
(2'-methoxy-5'-nitrophenyl) phthalide,
3- (2'-hydroxy-4'-diethylaminophenyl) -3- (2'-methoxy-5'-methylphenyl)
Phthalide, 3- (2'-methoxy-4'-dimethylaminophenyl) -3- (2'-hydroxy-4'-chloro-5'-methoxyphenyl) phthalide, 3-morpholino-7- (N-propyl- Trifluoromethylaniline)
Fluoran, 3-diethylamino-5-chloro-7-
(N-benzyl-trifluoromethylanilino) fluoran, 3-pyrrolidino-7- (di-p-chlorophenyl) methylaminofluoran, 3-diethylamino-5
-Chloro-7- (α-phenylethylamino) fluoran, 3- (N-ethyl-p-toluidino) -7- (α-
Phenylethylamino) fluoran, 3-diethylamino-7- (o-methoxycarbonylphenylamino) fluoran, 3-diethylamino-5-methyl-7- (α
-Phenylethylamino) fluoran, 3-diethylamino-7-piperidinofluoran, 2-chloro-3-
(N-methoxytoluidino) -7- (pn-butylanilino) fluoran, 3- (N-methyl-N-isopropylamino) -6-methyl-7-anilinofluoran,
3-dibutylamino-6-methyl-7-anilinofluoran, 3,6-bis (dimethylamino) fluorenespiro (9,3 ')-6'-dimethylaminophthalide, 3-
(N-benzyl-N-cyclohexylamino) -5,6
-Benzo-7-α-naphthylamino-4'-bromofluoran, 3-diethylamino-6-chloro-7-anilinofluoran, 3-N-ethyl-N- (2-ethoxypropyl) amino-6 Methyl-7-anilinofluoran, 3-N-ethyl-N-tetrahydrofurfurylamino-6-methyl-7-anilinofluoran, 3-diethylamino-6-methyl-7-mesitidino-4 ', 5' −
Benzofluoran, 3-N-methyl-N-isobutyl-
6-methyl-7-anilinofluoran, 3-N-ethyl-N-isoamyl-6-methyl-7-anilinofluoran, 3-diethylamino-6-methyl-7- (2 ',
4'-dimethylanilino) fluoran and the like.

Particularly preferred color formers used in the present invention are those containing halogen as a substituent. Examples of such a device include the following. 3,3-bis (p-dimethylaminophenyl) -6
-Chlorophthalide, 3-cyclohexylamino-6-chlorofluorane, 3-cyclohexylamino-6-bromofluorane, 3-diethylamino-7-chlorofluorane, 3-diethylamino-7-bromofluoran, 3
-Dipropylamino-7-chlorofluoran, 3-diethylamino-6-chloro-7-phenylamino-fluoran, 3-pyrrolidino-6-chloro-7-phenylamino-fluoran, 3-diethylamino-6-chloro-7
-(M-trifluoromethylphenyl) amino-fluoran, 3-cyclohexylamino-6-chloro-7- (o
-Chlorophenyl) amino-fluoran, 3-diethylamino-6-chloro-7- (2 ', 3'-dichlorophenyl) amino-fluoran, 3-diethylamino-6-
Methyl-7-chlorofluoran, 3-dibutylamino-
6-chloro-7-ethoxyethylamino-fluoran,
3-diethylamino-7- (o-chlorophenyl) amino-fluoran, 3-diethylamino-7- (o-bromophenyl) amino-fluoran, 3-diethylamino-7- (o-chlorophenyl) amino-fluoran, 3
-Dibutylamino-7- (o-fluorophenyl) amino-fluoran, 6'-bromo-3'-methoxybenzoindolino-pyrrospirane, 3- (2'-methoxy-
4'-dimethylaminophenyl) -3- (2'-hydroxy-4'-chloro-5'-chlorophenyl) phthalide, 3- (2'-hydroxy-4'-dimethylaminophenyl) -3- (2 '-Methoxy-5'-chlorophenyl) phthalide, 2- {3,6-bis (diethylamino)}-9- (o-chlorophenyl) amino-xanthyl benzoate lactam and the like.

A preferred color former when used in the present invention is a compound represented by the following general formula (3).

Embedded image (However, R ₁ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R ₂ is a hydrogen atom or an amino group which may be substituted, X is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or a phenylamino group. , M is an integer of 1 or 2, Y is a carbon number of 1-4.
An alkyl group or an alkoxy group having 1 to 2 carbon atoms, n is 1
Or an integer of 2. )

Specific examples of the compound represented by the general formula (3) include the following. 3-
(N-methyl-N-phenylamino) -7-amino-fluoran, 3- (N-ethyl-N-phenylamino)-
7-amino-fluoran, 3- (N-propyl-N-phenylamino) -7-amino-fluoran, 3- {N-
Methyl-N- (p-methylphenyl) amino} -7-amino-fluoran, 3- {N-ethyl-N- (p-methylphenyl) amino} -7-amino-fluoran, 3-
{N-propyl-N- (p-methylphenyl) amino}
-7-amino-fluoran, 3- {N-methyl-N-
(P-ethylphenyl) amino} -7-amino-fluoran, 3- {N-ethyl-N- (p-ethylphenyl)
Amino} -7-amino-fluorane, 3- {N-propyl-N- (p-ethylphenyl) amino} -7-amino-fluoran, 3- {N-methyl-N- (2 ′, 4′-dimethyl) Phenyl) amino} -7-amino-fluoran,
3- {N-ethyl-N- (2 ', 4'-dimethylphenyl) amino} -7-amino-fluoran, 3- {N-propyl-N- (2', 4'-dimethylphenyl) amino}
-7-amino-fluoran, 3- {N-methyl-N-
(P-chlorophenyl) amino} -7-amino-fluoran, 3- {N-ethyl-N- (p-chlorophenyl)
Amino} -7-amino-fluoran, 3- {N-propyl-N- (p-chlorophenyl) amino} -7-amino-fluoran, 3- (N-methyl-N-phenylamino) -7-methylamino -Fluoran, 3- (N-ethyl-N-phenylamino) -7-methylamino-fluoran, 3- (N-propyl-N-phenylamino) -7-
Methylamino-fluoran, 3- {N-methyl-N-
(P-methylphenyl) amino} -7-ethylamino-
Fluoran, 3- {N-ethyl-N- (p-methylphenyl) amino} -7-benzylamino-fluoran, 3
-{N-methyl-N- (2 ', 4'-dimethylphenyl)
Amino} -7-methylamino-fluoran, 3- {N-
Ethyl-N- (2 ′, 4′-dimethylphenyl) amino
-7-ethylamino-fluoran, 3- {N-methyl-
N- (2 ', 4'-dimethylphenyl) amino} -7-benzylamino-fluoran, 3- {N-ethyl-N-
(2 ′, 4′-dimethylphenyl) amino} -7-benzylamino-fluoran, 3- (N-methyl-N-phenylamino) -7-dimethylamino-fluoran, 3- (N
-Ethyl-N-phenylamino) -7-dimethylamino-fluoran, 3- {N-methyl-N- (p-methylphenyl) amino} -7-diethylamino-fluoran,
3- {N-ethyl-N- (p-methylphenyl) amino} -7-diethylamino-fluoran, 3- (N-methyl-N-phenylamino) -7-dipropylaminofluoran, 3- (N- Ethyl-N-phenylamino) -7
-Dipropylaminofluoran, 3- {N-methyl-N
-(P-methylphenyl) amino} -7-dibenzylamino-fluoran, 3- {N-ethyl-N- (p-methylphenyl) amino} -7-dibenzylamino-fluoran, 3- {N-ethyl -N- (p-methylphenyl)
Amino} -7-di (p-methylbenzyl) amino-fluoran, 3- {N-methyl-N- (p-methylphenyl) amino} -7-acetylamino-fluoran, 3-
{N-ethyl-N- (p-methylphenyl) amino}-
7-benzoylamino-fluoran, 3- {N-methyl-N- (p-methylphenyl) amino} -7- (o-methoxybenzoyl) amino-fluoran, 3- {N-ethyl-N- (p-methyl Phenyl) amino} -6-methyl-7-phenylamino-fluoran, 3- {N-methyl-N- (p-methylphenyl) amino} -6-methyl-7-phenylamino-fluoran, 3- {N- Methyl-N- (p-methylphenyl) amino} -6-tert
-Butyl-7- (p-methylphenyl) amino-fluoran, 3- (N-ethyl-N-phenylamino) -6
Methyl-7- (N-ethyl-N- (p-methylphenyl) amino-fluoran, 3- {N-propyl-N-
(P-methylphenyl) amino} -6-methyl-7-
{N-methyl-N- (p-methylphenyl) amino}-
Fluoran, 3- {N-ethyl-N- (p-methylphenyl) amino} -5-methyl-7-benzylamino-fluoran, 3- {N-ethyl-N- (p-methylphenyl) amino} -5 -Chloro-7-dibenzylamino-fluoran, 3- {N-methyl-N- (p-methylphenyl) amino} -5-methoxy-7-dibenzylamino-
Fluoran, 3- {N-ethyl-N- (p-methylphenyl) amino} -6-methyl-fluoran, 3- {N-
Ethyl-N- (p-methylphenyl) amino} -5-methoxy-fluoran and the like.

The developers are used alone or in combination of two or more. Similarly, the color former can be applied alone or in combination of two or more. The color former and the developer can be used as they are or encapsulated in microcapsules. Such a reversible thermosensitive recording material is prepared by uniformly dispersing or dissolving a color former and a developer together with a binder with water or an organic solvent according to a conventionally known method, and applying the same between the electrodes 21, 22, or 23. It is obtained by doing.

As the binder, various conventional binders can be appropriately used. For example, polyvinyl alcohol, hydroxyethyl cellulose, hydroxypropyl cellulose, methoxy cellulose, carboxymethyl cellulose, methyl cellulose, cellulose acetate, gelatin, casein, starch, polyacrylic acid Soda, polyvinylpyrrolidone, polyacrylamide, maleic acid copolymer, acrylic acid copolymer, polystyrene, polyvinyl chloride, polyvinyl acetate, polyacrylic esters, polymethacrylic esters, vinyl chloride / vinyl acetate copolymer Coalesce, styrene copolymer, polyester,
There are polyurethane and the like.

Microencapsulation of the color former and / or the developer can be carried out by a known method such as a coacervation method, an interfacial polymerization method, or an in-situ polymerization method. In the present invention, various additives used in ordinary thermosensitive recording paper, such as dispersants, surfactants, fillers, color image stabilizers, antioxidants, for the purpose of improving the coating properties or recording properties as necessary. Agents, light stabilizers, lubricants and the like can also be added.

[0050]

EXAMPLES All parts herein are by weight.

Example 1 A striped aluminum electrode was provided on a polyester film having a thickness of about 125 μm by vapor deposition. Next, a coating liquid consisting of 30 parts of carbon and 70 parts of epoxy resin was applied to the electrode side of the film and cured by heating to provide a resistance heating element having a thickness of about 5 μm. Next, an aluminum stripe electrode was provided on the resistance heating element by vapor deposition in a direction perpendicular to the electrode. Then, a liquid composed of 7 parts of behenic acid, 3 parts of eicosane diacid, 2 parts of diisodecyl phthalate, 40 parts of vinyl chloride / vinyl acetate copolymer (VYHH manufactured by UCC), 150 parts of THF, and 15 parts of toluene is coated on the striped electrodes. After processing and drying, a layer of a reversible thermosensitive recording material having a thickness of about 8 μm was provided to form a matrix display section having the configuration shown in FIG. The electrodes taken out from the matrix display section were connected to a display driver circuit of a card IC chip having the configuration shown in FIG. 3, and were inserted into a PVC card to produce an IC card as shown in FIG.

Example 2 A striped aluminum electrode was formed on a polyester film having a thickness of about 125 μm by vapor deposition. Next, on the electrode side of the film, 7 parts of behenic acid, 3 parts of eicosane diacid, 20 parts of ITO solution (20 parts of ELCOM manufactured by Catalysis Chemical Industry Co., Ltd.) 2 parts of diisodecyl phthalate, 40 parts of vinyl chloride / vinyl acetate copolymer (VYHH manufactured by UCC) A liquid consisting of 150 parts of THF and 15 parts of toluene was applied and dried to form a layer of a reversible thermosensitive recording material and a resistance heating layer having a thickness of about 10 μm, and a polyester film provided with an ITO striped electrode was laminated thereon. A matrix display unit having the configuration shown in FIG. 2 was created. The electrodes taken out of the matrix display section were connected to the display driver circuit of the card IC chip having the configuration shown in FIG. 3 to produce an IC card having the configuration shown in FIG.

Comparative Example Aluminum was vapor-deposited on a polyester film having a thickness of about 50 μm to form a metal reflection layer, on which 7 parts of behenic acid 3 parts of eicosane diacid 3 parts of diisodecyl phthalate 2 parts of vinyl chloride / vinyl acetate copolymer 40 Part (VYHH manufactured by UCC), a liquid consisting of 150 parts of THF and 15 parts of toluene was applied and dried to form a layer of a reversible thermosensitive recording material having a thickness of about 8 μm. Furthermore, a liquid consisting of 50 parts of acrylic UV effect resin (C7-157 made by Dainippon Ink) and 50 parts of toluene was applied, dried, and irradiated with UV to form a protective layer having a thickness of about 5 μm. Was made. This thermal display is attached to an existing IC card and printed with a thermal head.
Erasing was performed with a heat roller.

Printing and erasing were repeated in the above Examples and Comparative Examples. The following table shows the change in print density due to repeated printing. In the comparative example, the print density decreased after about 1000 repetitions, and became invisible. In contrast, in the embodiment, 10
Visibility could be maintained even after the repetition more than 000 times.

[Table 1]

[0055]

As described above, according to the present invention, a card having a display unit having high repetitive printing durability, particularly an IC card having a rewritable display unit having low power consumption and high durability is used in an IC card. We can provide the card.

[Brief description of the drawings]

FIG. 1 is a schematic view of an example of a card with a thermal display according to the present invention.

FIG. 2 is a schematic view of an example of a card with a thermal display according to the present invention.

FIG. 3 is a diagram showing a state where the card according to the present invention is connected to a display driver circuit of an IC chip.

FIG. 4 is a diagram showing how a card according to the present invention is used as an IC card.

FIG. 5 is an explanatory diagram showing that the reversible thermosensitive recording material layer according to the present invention causes a change in transparency depending on temperature.

FIG. 6 is an explanatory diagram showing that the reversible thermosensitive recording material layer according to the present invention causes a change in discoloration density depending on temperature.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Resistance heating layer 3 Reversible thermosensitive recording material layer 4 Polyester film 5 Protective layer 6 Resistance heating / reversible thermosensitive recording material layer 7 Connector 8 PVC base 9 Thermal display unit 21 Metal electrode 22 Electrode 23 Transparent electrode

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B41M 5/26 B42D 5/00-15/10 G06K 19/06-19/07

Claims (3)

(57) [Claims] 1. A Ri thermosensitive display portion is Na is formed by providing a layer of the reversible thermosensitive recording material between or on these arrayed resistance heating element in a two-dimensional array, and supplies a current to the resistive heating element Electric
Thermal display card with the poles, characterized in der Rukoto which also serves as the role of the light reflecting layer. 2. The reversible thermosensitive recording material is composed of a resin base material and an organic low-molecular substance dispersed in the resin base material, and is a material that reversibly changes its transparent and cloudy state by heating. claim 1 Symbol placement thermosensitive display with card. Wherein the reversible thermosensitive recording material, heat-sensitive display with a claim 1 Symbol placement coloring reaction is thermochromic compositions utilizing between the electron-donating coloring compound and an electron-accepting compound card.