JP2000006523A - Thermal transfer sheet and ic card employing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a signal communication with external connection terminals even in the formation of a protection layer on the electrode surface of an IC card giving the protection layer conductivity by adding in the protection layer a polythiophene of a specific formula in the presence of a poly-anion. SOLUTION: The thermal transfer sheet 1 includes a heat resistance slide layer lamination formed on the upper surface of a support sheet 2 through a primer layer 3 and a protection layer 6 lamination formed on the lower surface of the support sheet 2 through a release resin layer 5. The protection layer 6 provided on the release resin layer 5 comprises polythiophene contained in resin expressed by formula. In the formula, R1, R2 represent independently hydrogen or 1-4C alkyl group or conbinedly contain a polythiophene dispersant comprising a structural unit independently or corresponding to the formation of a 1-4C alkylene group that may be substituted at any time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer sheet used for forming a protective layer for protecting the surface of a card substrate, and an IC card having a protective layer formed using the thermal transfer sheet. More specifically, the present invention relates to a thermal transfer sheet having the protective layer having excellent conductivity made of a specific material and having the conductive protective layer, and an IC card using the same.

[0002]

2. Description of the Related Art Conventionally, in order to protect various images transferred and formed by a sublimation transfer method on the surface of a plastic card such as a credit card, a cash card, an ID card, a membership card, an employee card, etc. Forming a protective layer with a thermal transfer sheet on a part or the entire surface of a card base material containing a. These protective layers, for example, polyvinyl chloride, polystyrene, polyethylene, polypropylene, polycarbonate, acrylic, thermoplastic plastic film such as saturated polyester, polyurethane, thermosetting plastic film such as unsaturated polyester or cellulose acetate butyrate resin, A nitrocellulose resin, an ethylcellulose resin, or a composite resin thereof is used.

However, in recent years, there has been developed an IC card in which an IC module having an electrode surface for contacting an external connection terminal on its surface is embedded in a concave portion or the like formed in a card base material.
It is widely used in various card systems. When a protective layer for protecting the surface of this IC card is formed, the protective layer made of the above-mentioned materials is not conductive, so the surface of the electrode surface should be avoided and protected. A layer had to be formed. Therefore, when forming a protective layer on an IC card using a thermal transfer sheet, cut the thermal transfer sheet into a position overlapping with the electrode surface of the IC card so that the thermal transfer sheet does not contact the surface of the electrode surface of the IC card. There is a problem that a notch or the like must be provided, which takes time and effort in manufacturing, and that it is difficult to register the transfer position of the protective layer on the IC card and it is difficult to manufacture. In addition, it is not possible to protect the surface of the electrode surface of the IC card with a protective layer from the above circumstances, and the card base material and the electrode surface of the IC card generated when the IC card is possessed or used. There is a problem that rubbing and scratches cannot be prevented.

Further, in the conventional IC card, there is a risk that a defect may occur at the time of reading or writing of the IC due to the adverse effect of the static electricity on the IC chip, and it is necessary to prevent the charge, but a specific measure cannot be found. That was the current situation.

[0005]

SUMMARY OF THE INVENTION In order to prevent the above problems, the present invention includes an electrode surface in a card medium such as an IC card having an electrode surface in contact with an external connection terminal on the surface. An object of the present invention is to provide a thermal transfer sheet for forming a conductive protective layer on a card base material surface and an IC card using the same.
It is an object of the present invention to make the protective layer conductive so that signals can be exchanged with external connection terminals even when the protective layer is formed on the electrode surface of the IC card.
It is another object of the present invention to prevent the protection layer from being charged in order to prevent a failure during reading or writing of the IC due to an adverse effect of static electricity on the IC chip.

[0006]

In order to achieve the above object, a thermal transfer sheet according to the present invention has a protective layer formed on a support sheet so as to be capable of thermal transfer. Formula in the presence of anions

Embedded image In the formula, R ₁ and R ₂ are independently hydrogen or C ₁ ~ ₄ alkyl group, or the corresponding structural units to form a since it optionally an optionally substituted C ₁ ~ ₄ alkylene group with And a dispersion of polythiophene comprising:

[0007] An IC card according to the present invention is an IC card comprising an IC module having an electrode surface on its surface for contacting an external connection terminal, embedded in a card base material.
The protective layer formed on the surface of the electrode surface and the surface of the card base is formed by the thermal transfer sheet of the present invention.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the thermal transfer sheet of the present invention will be described in detail. FIG. 1 shows a sectional view of one embodiment of the thermal transfer sheet of the present invention. The heat transfer sheet 1 has a heat-resistant lubricating layer 4 laminated and formed on a top surface of a support sheet 2 with a primer layer 3 interposed therebetween.
A protective layer 6 is formed on the lower surface of the substrate with a release resin layer 5 interposed therebetween. In this drawing, as a transfer method, thermal transfer using a thermal head is assumed, but the transfer method is not limited to this, and a method using a hot roll or a hot stamp may be used. In the case of the method using a hot roll or hot stamp,
The heat-resistant lubricating layer 4 and the primer layer 3 are not always necessary.

[Thermal Transfer Sheet] (Support Sheet) The support sheet 2 used for the thermal transfer sheet 1 of the present invention may be any known one having a certain degree of heat resistance and strength. Paper having a thickness of about 0.5 to 50 μm, preferably about 3 to 10 μm, various processed papers, polyester film, polystyrene film, polypropylene film, polysulfone film, aramid film, polycarbonate film, polyvinyl alcohol film, polyethylene terephthalate film, cellophane And particularly preferred are a polyester film and a polyethylene terephthalate film. These support sheets may be of a single-wafer type or a continuous film, and are not particularly limited. When a polyethylene terephthalate film is used, its thickness is preferably 5 to 25 μm in consideration of workability, tensile strength, thermal efficiency during thermal transfer, and the like.

(Primer Layer) The primer layer 3 formed on one surface of the support sheet 2 is formed as a binder having good adhesion to both the support sheet 2 and the heat-resistant lubricating layer 4. Examples of the binder include polyester resins, polyurethane resins, polyacrylic resins, polyvinyl formal resins, epoxy resins, polyvinyl butyral resins, polyamide resins, polyether resins, polystyrene resins, and styrene-acrylic resins. Polymeric resins and the like, among these, a water-soluble or water-dispersible polyester resin having a carboxyl group, adhesion to the substrate, compatibility with sulfonated polyaniline, adhesion to the heat-resistant lubricating layer, etc. It is particularly preferable in view of the point. For example, it can be obtained from Nippon Synthetic Chemical Industry Co., Ltd. under the trade name of Polyester WR-961 and used in the present invention.

(Heat-resistant lubricating layer)
A heat-resistant lubricating layer 4 made of a thermoplastic resin is formed on the surface of the substrate. As the thermoplastic resin, a polyester resin,
Polyacrylate resin, polyvinyl acetate resin, styrene acrylate resin, polyurethane resin, polyolefin resin, polystyrene resin, polyvinyl chloride resin, polyether resin, polyamide resin, polycarbonate resin, polyethylene Resins, polypropylene resins, polyacrylate resins, polyacrylamide resins, polyvinyl chloride resins, polyvinyl butyral resins, thermoplastic resins such as polyvinyl acetoacetal resins or silicone modified products thereof are used, and among these, particularly preferred resins are It is a resin having a hydroxyl group that reacts with an isocyanate group, such as a polyvinyl acetal resin such as a polyvinyl butyral resin and a polyacetoacetal resin, or a modified silicone thereof.

In order to form the heat-resistant lubricating layer 4, a coating solution is prepared by dissolving or dispersing the above-mentioned materials in an appropriate solvent such as acetone, methyl ethyl ketone, toluene, or xylene. It is formed by coating and drying by a conventional coating means such as a gravure coater, a roll coater, and a wire bar, and then performing a crosslinking treatment by a heat treatment. The thickness of the coating amount, or heat-resistant lubricating layer be important, on a solids basis 2.0 g / m ² or less in the present invention, preferably sufficient performance in 0.1 to 1.0 g / m ² Thickness A heat-resistant lubricating layer can be formed.

(Releaseable Resin Layer) A releasable resin layer 5 laminated on the other surface of the support sheet 2 by coating or the like adheres well to the support sheet 2 and is formed thereon. It is preferable to form the protective layer 6 from a resin that can be relatively easily peeled off and has excellent heat resistance and solvent resistance. As such a resin, for example, various thermosetting resins having excellent crosslinking properties such as a melamine resin can be suitably used. By using such a resin while controlling the degree of crosslinking, the peeling force at the time of transfer can be appropriately adjusted. The releasable resin layer 5 can be formed by a coating method using a reverse roll coater or the like, and its thickness may be thin, and about 0.1 to 4 μm is sufficient.

(Protective Layer) The protective layer 6 provided on the release resin layer 5 is made of the following resin containing polythiophene having a structural formula described in JP-A-7-90060. The polythiophenes having the structural formula described in the above-mentioned JP-A-7-90060 are as follows.

Formula in the presence of a polyanion

[0016]

Embedded image

[0017] formula, R ₁ and R ₂ represent independently hydrogen or C ₁ ~ ₄ alkyl group, or since it optionally an optionally substituted C ₁ ~ ₄ alkylene group together, preferably optionally alkyl optionally substituted methylene group, optionally C ₁ ~ ₁₂ - alkyl or phenyl optionally substituted 1,2-ethylene group, a 1,3-propylene group or a 1,2-cyclohexylene group, the corresponding The present invention relates to a dispersion of polythiophene composed of the following structural units.

All methyl and ethyl groups are R ₁ and R ₂
Mentioned above as C ₁ ~ ₄ alkyl groups relative.

R ₁ and R ₂ may form together,
The preferred representatives of the optionally optionally substituted C ₁ to ₄ alkylene group α- olefins such as ethene, prop-1
Ene, hex-1-ene, oct-1-ene, des-1
-1,2-alkylene groups derived from 1,2-dibromoalkanes obtained by bromination of -ene, dodes-1-ene and styrene. Other representatives include 1,2-cyclohexyl, 2,3-butylene, 2,3-dimethyl-
There are 2,3-butylene and 2,3-pentylene groups.

Preferred R ₁ and R ₂ are methylene, 1,2-
These are ethylene and 1,3-propylene groups, with 1,2-ethylene being particularly preferred.

The polyanions are polymeric carboxylic acids such as polyacrylic acid, polymethacrylic acid or polymalenic acid, and polymeric sulfonic acids such as polystyrene sulfonic acid and polyvinyl sulfonic acid. Also, these polycarboxylic acids and polysulfonic acids can be copolymers of vinylcarboxylic acid and vinylsulfonic acid with other polymerizable monomers such as acrylates and styrene.

The molecular weight of the polyacid supplying the polyanion is preferably in the range of 1,000 to 2,000,000, more preferably in the range of 2,000 to 500,000.

The polythiophene having the structural formula described in the above-mentioned Japanese Patent Application Laid-Open No. 7-90060 has been commercialized by Bayer AG in Germany under the trade name of the conductive polymer "Baytron P".

The resin used for the protective layer 6 contains polythiophene having the structural formula described in the above-mentioned JP-A-7-90060, so that it has conductivity and becomes the outermost layer of a card or the like and has a lower side. A resin that protects the layer and has transparency, abrasion resistance, abrasion resistance, heat resistance, chemical resistance, stain resistance and the like is suitable. Examples of such resins include thermoplastic resins such as acrylic resins, polyvinyl chloride, polystyrene and polycarbonate, polyesters, melamine resins, thermosetting resins such as epoxy resins, and further ionizing radiation-curable resins. Specific examples include polyurethane acrylate, polyester acrylate, epoxy acrylate, polyether acrylate, and the like. These are prepared by adding a polyfunctional or monofunctional monomer to each prepolymer to adjust the viscosity or crosslink density. It may be used, or a known photoreaction initiator or sensitizer may be added as necessary. In addition, a polyene / thiol-based ionizing radiation curable resin and the like are also excellent in abrasion resistance and can be preferably used.

If necessary, additives such as a surfactant, an antistatic agent, and an ultraviolet absorber may be added to the resin for the protective layer as described above. Further, a method for providing a protective layer is as follows. After a coating solution is prepared from the resin composition for a protective layer and applied by various known roll coating methods or gravure coating methods, UV (ultraviolet) irradiation or EB (electron beam) irradiation is performed. ) The protective layer can be formed by curing the resin by irradiation or the like. In order to adjust the viscosity, an appropriate organic solvent may be added to the coating solution, if necessary. In this case, after coating, first, hot air drying is performed to remove the organic solvent, and then UV or EB is applied. The curing of the resin may be performed by the irradiation.

Further, an adhesive layer may be provided in order to increase the adhesive strength with a transfer object such as an IC card. This is particularly necessary when a curable resin is used for the protective layer. Acrylic resins, vinyl chloride-vinyl acetate copolymers, ethylene-vinyl acetate copolymers, polyester resins, urethane resins, amide resins, epoxy resins, rubber resins, and the like are used. These must contain polythiophene for conductivity. The thickness of the adhesive layer is about 0.1 to 10 μm. As described above, the heat-resistant lubricating layer is formed on one surface of the support sheet via the primer layer, and the conductive polythiophene is formed on the other surface of the support sheet via the release resin layer. The thermal transfer sheet on which the protective layer containing is formed is formed.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in more detail with reference to the drawings. However, the present invention is not limited to these drawings and examples.

FIG. 1 is a cross-sectional view illustrating the configuration of an embodiment of the thermal transfer sheet 1 of the present invention, FIG. 2 is a cross-sectional view of an IC card having a protective layer formed using the thermal transfer sheet 1, and FIG. FIG. 4 is a perspective view of the IC card of the embodiment in which the IC module is divided into several terminals and formed. In FIG. 1, a support sheet 2 has a thickness 1
6 μm polyethylene terephthalate film,
An ink having the following composition was used on one surface of the support sheet 2 and a primer layer 3 having a thickness of 0.5 μm and a
The heat-resistant lubricating layer 4 having a thickness of 5 mm was formed. In the text, part or%
Unless otherwise specified, the values are based on weight.

Ink for primer layer: Acrylic resin (BR-85 30 solution, manufactured by Mitsubishi Rayon) 100 parts Antistatic agent (TB-34, manufactured by Matsumoto Yushi) 5 parts Solvent (MEK / toluene = 1/1) 500 parts Heat resistance Slip layer ink: polyvinyl butyral resin (BX-1: manufactured by Sekisui Chemical) 80 parts Polyisocyanate curing agent (Bernock D750, manufactured by Dainippon Ink) 35 parts (NCO / OH = 1.8) Phosphate ester (Plysurf) A-208S, Daiichi Kogyo Seiyaku) 5 parts Solvent (MEK / toluene = 1/1) 500 parts

Further, on the other surface of the support sheet 2,
In order to form the release resin layer 5, a coating liquid for the release resin layer having the following composition was applied by a gravure reverse coating method so that the thickness when dried was 0.5 μm. Composition of coating solution for release resin layer: melamine resin 5 parts Solvent methyl alcohol 25 parts Solvent ethyl alcohol 45 parts Cellulose acetate resin 1 part Paratoluenesulfonic acid 0.05 part

Next, a protective layer 6 is formed on the surface of the release resin layer 5.
In order to form a coating liquid, a coating liquid for a protective layer having the following composition was applied by bar coating so that the thickness when dried was 2 μm. Composition of coating solution for protective layer: vinyl chloride-vinyl acetate copolymer resin 20 parts polyester resin 20 parts polythiophene (manufactured by Bayer, Baytron CPP105) 30 parts toluene 20 parts methyl ethyl ketone 20 parts

Next, in order to form an adhesive layer 7 on the surface of the protective layer 6, an adhesive layer coating solution having the following composition was applied by a bar coater so that the thickness when dried was 1 μm. Composition of coating solution for protective layer: Vinyl chloride-vinyl acetate copolymer resin 20 parts Polythiophene (Baytron, Baytron) 20 parts Toluene 10 parts Methyl ethyl ketone 10 parts

A thermal transfer sheet having the above configuration was prepared, and FIG.
As shown in (1), the protective layer 6 was transferred to the entire surface of the IC card 8 using a hot roll. In addition, the IC module 10
However, when it was divided into several terminals as shown in FIG. 4, the transfer was performed in a pattern along the boundaries of the individual terminals. Further, in the IC card in which the protective layer of the present invention is formed by the thermal transfer sheet 1, the protective layer 6 having conductivity covers the surface of the electrode 9 of the IC card by the thermal transfer sheet 1. 6, and can be electrically connected to an external connection terminal. FIG.
FIG. 2 shows a perspective view of a state in which the protective layer 6 has been transferred to the entire surface of the IC card 8 using a heat roll.
The transfer area may be set as necessary on the entire surface of the C card 8 or on the peripheral portion of the surface of the electrode 9 of the IC module 10 embedded in the IC card 8. In the IC card 8, an IC module 10 having a surface of an electrode 9 in contact with an external connection terminal on the surface is formed by being embedded in a card base material.

The configuration of the IC module 10 is, for example, as shown in FIG.
The electrode 12 on the IC chip 11 and the circuit pattern 1
3 are connected by a conductor 14 by a wire bonding method. The circuit pattern 13
The electrode 9 and the surface of the electrode 9 are electrically connected to each other through a through hole 15 at a necessary place. Normally, signals are exchanged by directly connecting the surface of the electrode 9 of the IC card 8 to an external connection terminal, thereby conducting signal communication. However, since the protective layer 6 of the present invention has conductivity, the upper surface of the electrode 9 is not covered. When an external connection terminal is brought into contact with the portion of the protection layer 6 transferred to the external connection terminal, and electricity flows from the external connection terminal, the electricity is transmitted to the surface of the electrode 9 through the protection layer, thereby performing normal data reading and writing processing on the IC card 8. I was able to. In addition, the adverse effects due to static electricity could be reduced.

[0035]

As described above in detail, the thermal transfer sheet of the present invention has a structure in which the protective layer to be transferred contains polythiophene of the structural formula described in JP-A-7-90060, which has conductivity. Even if the protective layer is transferred to a transfer object having an electrode surface on the surface, such as a card, the electrical treatment can be performed without providing an insulating state by providing the protective layer as in the related art. It is. Therefore, it is possible to transfer and form the protective layer even to a person who could not prevent the rubbing or the like by the conventional protective layer. Further, since the IC card of the present invention has a protective layer formed on the surface of the IC card by the thermal transfer sheet, the surface of the card is protected by the protective layer, and the electrode surface of the IC card 7 is directly Since electrical processing can be performed without connecting to the external connection terminal, scratches and wear due to rubbing of the electrode surface by the external connection terminal can be prevented, and the IC chip can be protected from static electricity. Things.

[0036]

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of one embodiment of a thermal transfer sheet of the present invention.

FIG. 2 is a cross-sectional view of an IC card on which a protective layer is formed using the thermal transfer sheet of the present invention.

FIG. 3 is a perspective view of the IC card of FIG. 2;

FIG. 4 is a perspective view of an IC card according to an embodiment in which an IC module is divided into several terminals.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 thermal transfer sheet 2 support sheet 3 primer layer 4 heat-resistant lubricating layer 5 release resin layer 6 protective layer 7 adhesive layer 8 IC card 9 electrode 10 IC module 11 IC chip 12 electrode 13 circuit pattern 14 conductor 15 through hole

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G06K 19/077 C09D 5/00 G // C09D 5/00 B41M 5/26 101Z G06K 19/00 K

Claims (2)

[Claims] 1. A thermal transfer sheet having a protective layer (6) formed so as to be thermally transferable on a support sheet (2),
The protective layer (6) has the formula in the presence of a polyanion. In the formula, R ₁ and R ₂ are independently hydrogen or C ₁ ~ ₄ alkyl group, or the corresponding structural units to form a since it optionally an optionally substituted C ₁ ~ ₄ alkylene group with A thermal transfer sheet comprising a polythiophene dispersion comprising: 2. An IC card in which an IC module (10) having an electrode (9) surface for contacting an external connection terminal on the surface is embedded in a card base material, and the surface of the electrode (9) surface and the card are provided. An IC card comprising a protective layer (6) formed on a surface of a substrate and formed by the thermal transfer sheet (1) according to claim 1.