JP3114977B2 - Thermal transfer sheet - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a thermal transfer sheet, and more particularly, is economical, does not cause background contamination on a material to be transferred, and furthermore, such as an identification card. The present invention relates to a thermal transfer sheet that simultaneously includes a photographic tone image and a monotone image such as characters and symbols and is capable of forming an image with excellent durability.

(Conventional technology and its problems) Conventionally, a thermal transfer method has been widely used as a simple printing method. In these thermal transfer methods, since various images are easily formed, the thermal transfer method is used for producing a printed matter that requires a relatively small number of prints, for example, an ID card such as an identification card.

Also, when a color image such as a face photograph is preferable,
For example, yellow (Y), magenta (M) and cyan (C) are formed on a continuous long base film 1 as shown in FIG.
Further, a thermal transfer method using a long thermal transfer sheet provided with a large number of colored thermal transfer layers (black (Bk) as necessary) repeated in a plane-sequential manner has been performed.

Such thermal transfer sheets are roughly classified into two types: a thermal transfer sheet of a so-called hot-melt ink transfer type, in which the thermal transfer layers are softened by heating and thermally transferred to the thermal transfer material in an image form, and a dye in the thermal transfer layer is heated by heating. It is roughly classified into a so-called sublimation dye transfer type thermal transfer sheet in which only the dye is sublimated (heat transferred) and only the dye is thermally transferred onto the heat transfer material in an image form.

When an image is formed on such a thermal transfer sheet, there is no problem if the image forming area of the material to be transferred has the same size as the thermal transfer layer. However, as shown in FIG.
When only a part of the image forming area 22 is the image forming area 22, the thermal transfer layer not corresponding to the image forming area 22 is not used, which is uneconomical.

An even more important problem is that when the image forming area 22 of the transfer material 21 is small as shown in FIG. 2 and a margin is present around the area, the periphery of the image forming area 22 is stained by friction with the thermal transfer layer. That is, so-called soiling occurs.

In particular, when the transfer target material 21 is a plastic card, the card base is thick and hard, and in order to develop an image with higher density, the printing pressure of the head is increased during printing. As a result, the above-mentioned background stain becomes more remarkable.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a thermal transfer sheet which is economical and does not cause background contamination.

(Means for Solving the Problems) The above object is achieved by the present invention described below. That is,
The present invention provides a thermal transfer sheet comprising at least a sublimable dye layer and a hot-melt ink layer provided on a long base film in a face-to-face order, wherein the sublimable dye layer and the hot-melt ink layer are formed of a material to be transferred. A thermal transfer sheet, wherein the thermal transfer sheet is formed in a pattern at non-overlapping positions in the image forming area.

(Function) By forming the thermal transfer layer in a pattern on a specific area of the substrate film corresponding to the image forming area of the material to be transferred, an unused thermal transfer layer is reduced, and a blank portion of the material to be transferred is formed. Can be prevented from being soiled.

Preferred Embodiment Next, the present invention will be described in more detail with reference to the accompanying drawings, which schematically show preferred embodiments.

FIG. 1 is a plan view of a conventional thermal transfer sheet. In the case of the conventional thermal transfer sheet, as shown in FIG. (Y), magenta (M), cyan (C)
And a black (Bk) thermal transfer layer.

With such a thermal transfer sheet, an image forming area is formed as shown in FIG.
When 22 is a part of the transfer material 21, a desired image is formed in the image forming area 22 as a matter of course, but a thermal transfer layer that does not correspond to the image forming area 22 is not used, so that it is uneconomical.
In particular, since these unused thermal transfer layers are also in contact with blank portions other than the image forming region 22 of the transfer material 21, background smearing occurs in the blank portions.

Hereinafter, typical embodiments of the present invention will be described with reference to the drawings.

FIG. 4a shows an example of a sublimation dye layer Y, M comprising yellow, magenta and cyan hue regions on a base film 1.
C and C, and a black heat-meltable ink layer Bk is formed face-sequentially. Note that no thermal transfer layer was formed in the square of Bk.

In the case of this thermal transfer sheet, since the sublimable dye layers of Y, M and C all correspond to the image forming area 22 of the transfer-receiving material 21 in FIG. Such a gradation image is formed. Also, the black hot-melt ink layer Bk
Corresponds to the monotone image forming area 23 of the transfer material 21 in FIG. 2, so that a monotone image such as characters and symbols can be formed in this area 23.

The example of FIG. 5A is obtained by adding a transfer protection layer 4 to the example of FIG. 4A. If this thermal transfer sheet is used, for example, a gradation image such as a face photograph is formed in the gradation image forming region 22 of the transfer-receiving material shown in FIG. Then, a monotone image such as a character or a symbol is formed by the thermal transfer layer of Bk, and then a protective layer is transferred to the surface of the gradation image to improve durability such as abrasion resistance of the gradation image.

In the example of FIG. 5B, the area of the transfer protection layer 4 is enlarged, and the protection layer can be applied to both the gradation image and the monotone image in the same manner as described above. Even if the area of the protective layer 4 has a large area, the protective layer is transparent and does not contaminate an image or a blank portion.

The example shown in FIG. 6 is an improved type of the example shown in FIG.
The thermal transfer layer and the thermal transfer layer of Bk are provided without being overlapped in the same area, and the entire length of the thermal transfer sheet can be saved.

In the example shown in FIG. 8, a blank is provided between C and Bk in the example shown in FIG. 6, so that the background stain around the gradation image can be more effectively prevented.

The example shown in FIG. 9 is a modification of the example shown in FIG. 8, in which Bk does not surround C. As described above, Bk does not need to surround C, and it is sufficient if Bk corresponds to the region 23 of the transfer material on which a monotone image is to be formed.

FIG. 10 is a cross-sectional view of the thermal transfer sheet of FIG. 5b, and is a view for explaining a preferred configuration of each thermal transfer layer.

In the drawing, 1 is a substrate film, 2 is a sublimable dye layer, 3 is a heat-meltable ink layer, 4 is a transfer protective layer, 5 is a release layer, 6 is a heat-resistant lubricating layer on the back, and 7 is The adhesion improving layer, 8, 8 ', represents the heat-sensitive adhesive layer.

First, the common part will be described. As the base film 1 of the composite thermal transfer sheet, the same base film as used in the conventional thermal transfer sheet can be used as it is, and other types can be used. , Is not particularly limited.

Specific examples of preferred base film 1 include, for example,
Thin paper such as glassine paper, condenser paper, and paraffin paper is useful.In addition, for example, polyester, polypropylene, cellophane, polycarbonate, cellulose acetate, polyethylene, polyvinyl chloride, polystyrene, nylon, polyimide, polyvinylidene chloride, ionomer, etc. Or a base film in which these are combined with the above-mentioned paper. The thickness of the substrate film 1 can be appropriately changed depending on the material so that the strength and heat resistance are appropriate, but the thickness is preferably 3 to 100 μm.

Reference numeral 6 denotes a heat-resistant lubricating layer, which has an action of preventing adhesion of a thermal head of a printer. This layer 6 is unnecessary when the heat resistance and the slip property of the base film 1 are good.

Reference numeral 7 denotes an adhesion improving layer, which improves the adhesion of the sublimable dye layer 2 to the base film 1 and improves the adhesion between the transfer protection layer 4 and the base film 1 to improve the transfer protection layer. 4 has the effect of improving the cutting of the foil. If the adhesion between the base film 1 and the transfer protection layer 4 is poor without providing the layer 7, the protection layer 4 other than the heated portion is peeled off together with the protection layer 4 in the heated portion during thermal transfer, and the foil breaks. Gets worse.

The adhesion improving layer 7 may be any as long as the adhesion between the base film 1 and the dye layer 2 and the transfer protection layer 4 is further strengthened. For example, a polyurethane resin, an acrylic polyol resin, a vinyl chloride / vinyl acetate copolymer may be used. A coalescence is formed by coating or drying alone or in combination. Also, a reactive curing agent such as polyisocyanate may be added as necessary,
Further, titanate and silane coupling agents may be used. Further, if necessary, two or more layers may be laminated.

Reference numerals 8 and 8 'denote a heat-sensitive adhesive layer, which has an effect of facilitating the transferability of the hot-melt ink layer 3 and / or the transfer protection layer 4 to the material to be transferred.

When the material to be transferred is made of polyvinyl chloride, for example, like a card base material, the heat-sensitive adhesive layers 8, 8 ' , Vinyl chloride resin, vinyl chloride / vinyl acetate copolymer resin, acrylic / vinyl chloride / vinyl acetate copolymer,
It is preferably formed to a thickness of about 0.1 to 5 μm by applying and drying a solution of a resin having good adhesiveness when heated, such as a polyester resin and a polyamide resin.

 Next, each thermal transfer layer will be described.

The dye layer 2 is a layer in which a sublimable dye is carried on the base film 1 (adhesion improving layer 7) with an optional binder resin.

As the dye to be used, any dye conventionally used in a sublimation type thermal transfer sheet can be effectively used in the present invention, and is not particularly limited. For example, some preferred dyes include, as red dyes, MS Red G, Macr
olex Red Violet R, Ceres Red 7B, Samaron Red HBS
L, SK Rubin SEGL, etc., and as a yellow dye, Holon Brilliant Yellow S-6GL, PTY-52, Macrolex Yellow S-6G, Kayaset Yellow DI-
055 and the like, and as the blue dye, Kayaset Blue 714, Waxolin Blue AP-FW, Holon Brilliant Blue SR, MS Blue 100, Daito Bel No. 1
And the like.

As a binder for supporting the dye as described above,
Any of the conventionally known ones can be used, and preferred examples thereof include ethylcellulose, hydroxyethylcellulose, ethylhydroxycellulose, hydroxypropylcellulose, methylcellulose, cellulose acetate, cellulose resins such as cellulose acetate butyrate, polyvinyl alcohol, and polyvinyl acetate. And vinyl-based resins such as polyvinyl butyral, polyvinyl acetal, polyvinyl pyrrolidone and polyacrylamide. Among them, polyvinyl acetal and polyvinyl butyral are particularly preferred from the viewpoint of heat resistance and heat transfer property of the dye.

The dye layer 2 is basically formed from the above materials,
In addition, various conventionally known additives can be included as needed.

Such a dye layer 2 is preferably prepared by adding the above-mentioned dye, binder resin and other optional components in an appropriate solvent and dissolving or dispersing each component to prepare an ink for forming a dye layer. It is formed on the base film 1 by printing and drying by a method or the like.

Of course, the printing may be performed in a single color, but for the purpose of the present invention, a multicolor printing of three colors of yellow, magenta, and cyan or four colors including black is preferable so that a color image can be formed.

The dye layer 2 thus formed has a thickness of 0.2 to 5.0 μm,
It is preferably about 0.4 to 2.0 μm thick, and the dye in the dye layer 2 is present in an amount of 5 to 90% by weight, preferably 10 to 70% by weight of the weight of the dye layer. is there.

The hot-melt ink layer 3 is formed adjacent to the dye layer 2 from an ink containing necessary materials.

The ink for forming the hot-melt ink layer comprises a colorant and a vehicle, and may further contain various additives as necessary. As the colorant, among organic or inorganic pigments or dyes, those having good properties as a recording material, for example, having a sufficient coloring density, light,
Those which do not discolor by heat, temperature, etc. are preferred. As the colorant, cyan, magenta, yellow and the like can be used, but for the purpose of the present invention, a black colorant capable of printing clear characters and symbols at high density is preferable.

As the vehicle, a mixture of wax as a main component, and other components such as a wax and a derivative of a drying oil, a resin, a mineral oil, cellulose, and rubber is used. Representative examples of the wax include microcrystalline wax, carnauba wax, and paraffin wax. Furthermore, various waxes such as Fischer-Tropsch wax, various low molecular weight polyethylene, wood wax, beeswax, spermaceti, Ibota wax, wool wax, shellac wax, candelilla wax, petrolactam, partially modified wax, fatty acid ester, fatty acid amide, etc. Used.

In particular, when the material to be transferred is, for example, made of polyvinyl chloride such as a card substrate, it is more preferable to use the following resin binder from the viewpoint of adhesion to the card substrate and scratch resistance. .

Acrylic resin Acrylic resin + chlorinated rubber Acrylic resin + vinyl chloride / vinyl acetate copolymer resin Acrylic resin + cellulose resin Vinyl chloride / vinyl acetate copolymer resin On base film 1 or on release layer 5 previously provided thereon Examples of the method for forming the hot-melt ink layer 3 include a method of applying the ink by hot lacquer coating, gravure coating, gravure reverse coating, roll coating, and other various means in addition to hot melt coating.
The thickness of the ink layer to be formed should be determined so as to balance the required density with the thermal sensitivity. For example, the thickness of the ink layer is usually preferably in the range of about 0.2 to 10 μm.

Prior to the formation of the heat-meltable ink layer, it is preferable to form a release layer 5 on the surface of the adhesion improving layer 7 of the base film 1 in order to facilitate the release of the ink layer. Such a release layer 5 is made of waxes, silicone wax,
It is formed from a release agent such as a silicone resin, a fluorine resin, an acrylic resin, a cellulose resin, a vinyl chloride / vinyl acetate copolymer resin, or a nitrified surface resin. The forming method may be the same as the method for forming the sublimable dye layer or the hot-melt ink layer, and the thickness of about 0.1 to 5 μm is sufficient. If matte printing is desired after transfer, the release layer 5 can be made to contain various particles to form a matte surface. Further, if the release layer 5 is transferred to the transfer material simultaneously with the ink layer, the release layer also serves as a protective layer for the ink layer 3 after the transfer.

The layers 5 to 8 are not essential in the present invention, but when the adhesion improving layer 7 is provided, the release layer 5 is preferably provided.

Further, a transfer protection layer 4 made of a transparent resin layer and a heat-sensitive adhesive layer 8 'are provided on the adhesion improving layer 7 so as to be peelable.

The transfer protection layer 4 provided on the adhesion improving layer 7 is preferably formed from a mixture of a transparent resin and wax.

Examples of the transparent resin include a polyester resin, a polystyrene resin, an acrylic resin, an epoxy resin, a modified cellulose resin, a polyvinyl acetal resin, a silicone resin, a fluorine resin, and the like. Particularly preferred are an acrylic resin, a silicone resin, and a fluorine resin. . These resins have excellent transparency and form a relatively tough film.
In addition, film breakage during transfer is sufficient. However, since the lubricity is insufficient, it is easily damaged by surface friction. In the present invention, the lubricity of the protective layer 4 is improved by mixing wax with these transparent resins.

Representative examples of the wax used in the present invention include microcrystalline wax, carnauba wax, and paraffin wax. Furthermore, various waxes such as Fischer-Tropsch wax, various low molecular weight polyethylenes, wood wax, beeswax, spermaceti, Ibota wax, wool wax, shellac wax, candelilla wax, petrolactam, partially modified wax, fatty acid ester, fatty acid amide and the like are used. Can be

The amount of the wax used is preferably in the range of 0.5 to 20 parts by weight per 100 parts by weight of the transparent resin. If the amount of the wax is too small, the abrasion resistance of the protective layer 4 becomes insufficient. In addition, the durability and transparency of the protective layer 4 become insufficient, which is not preferable.

The mixing method of the transparent resin and the wax is not particularly limited, for example, a method of melting and mixing the two, and a method of dissolving the two in a suitable organic solvent to form a bone.

It is particularly preferable to use a transparent resin as a dispersion (or an emulsion), while using wax as a solution or a dispersion (an emulsion), and to mix both. After using such a dispersion liquid (emulsion liquid) and applying it to a base film, drying is performed at a relatively low temperature to form a film so that at least a part of these resin particles remains. The coating thus formed has a rough surface due to the remaining resin particles and is partially cloudy, but the surface becomes smooth by heat and pressure during thermal transfer and can be transferred as a transparent coating.

Examples of a method for forming the transfer protection layer 4 include a method of applying and drying an ink composed of the resin and the wax by a gravure coat, a gravure reverse coat, a roll coat, and other various means.

When the transfer protective layer 4 is formed from a mixed dispersion of resin and wax, drying after coating can be performed at a temperature lower than the melting point of the resin particles, for example, at a relatively low temperature of about 50 to 100 ° C. preferable. By drying at such a temperature, the film is formed with the resin particles remaining, so that the film breakage of the protective layer 4 during thermal transfer is significantly improved, and the smoothness of the protective layer is maintained.

The transfer protective layer 4 can be mixed with substantially transparent inorganic or organic fine particles. By mixing such fine particles, the transfer protective layer can be further improved in foil breakage, abrasion resistance and the like. Further, the surface gloss of the protective layer 4 can be suppressed, and a matte surface can be obtained. Preferred examples of such fine particles include those having relatively high transparency such as silica, Teflon powder and nylon powder. The addition amount of these fine particles is preferably 1 to 30% by weight based on the resin of the protective layer 4. If the amount is too large, the transparency and durability of the protective layer will be reduced.

If the adhesion between the transfer protective layer 4 and the adhesion improving layer 7 is too high, the transferability of the transfer protective layer 4 may be inferior. Although not shown, a release layer similar to the release layer 5 is preferably provided.

The transfer protective layer 4 and / or the heat-sensitive adhesive layer 8 'contain additives such as an ultraviolet absorber, an antioxidant, and a fluorescent whitening agent, so that gloss and light resistance of various images to be coated can be improved. Properties, weather resistance, whiteness and the like can be improved.

The image to be protected by using the thermal transfer sheet including the protective layer as described above is a monotonous image formed on the material to be transferred, such as a gradation image by a sublimation type thermal transfer method or a symbol such as a character or a bar code by a molten ink type thermal transfer method. Images are preferred, but not limited to these images. Particularly when applied to a sublimation transfer image, the protective layer of the image is formed, and the dye forming the image is recolored by heat during transfer, so that the image is further sharpened. There is.

Although the composite thermal transfer sheet is provided as described above, the forming method is not limited to these methods, and the forming order of the sublimable dye layer, the heat-meltable ink layer, the transfer protective layer, and the like is not particularly limited.

Example 11 of manufacturing a card using the composite thermal transfer sheet
This will be described with reference to the drawings.

First, the dye layer 2Y of the thermal transfer sheet is superimposed on the gradation image forming area 22 of the card base 9 (21) as shown in FIG. 2 and the yellow image 2Y is transferred by a thermal printer operating according to a color separation signal. Magenta image 2M in the same area
And transfer the cyan image 2C to the desired color image 10
Form 22.

Next, using the heat-fusible ink layer 3,
The symbol 3 is printed in the monotone image forming area 23. Further, the protective layer 4 is transferred onto the color image 10 and / or the image 3 such as a character using the transfer protective layer 4 to form the protective layer 4. Thus, a desired card is obtained.

In the above transfer, the thermal printer may be set separately (preferably continuously) for sublimation transfer, for hot-melt ink transfer, and for protection layer transfer. The printing energy may be appropriately adjusted by each of the printers.

Although the present invention has been described above with reference to a specific composite thermal transfer sheet as a representative example, the present invention is not limited to this example.
Naturally, the monotone image and the protective layer may be formed using separate thermal transfer sheets of the present invention.

Further, the card base material has been described as an example of the transfer material, but it is obvious that the transfer material may be any material as long as it is a heat transferable material.

(Effects) According to the present invention as described above, the thermal transfer layer is formed in a specific area of the base film corresponding to the image forming area of the material to be transferred in a pattern, so that the unused thermal transfer layer is reduced. Further, it is possible to prevent the background from being stained in a blank portion of the transfer material.

In a preferred embodiment, a gradation image and a monotone image can be simultaneously formed by providing at least one color sublimable dye layer and at least one color heat-meltable ink layer on the same base film. By adding a transfer protection layer, a gradation image is formed with a sublimable dye layer, and a monotonous image is formed with a heat-meltable ink layer, and then the transfer protection layer is transferred to a required area, so that a simple operation can be performed. It is possible to provide a thermal transfer sheet capable of simultaneously forming a gradation image and a monotone image having excellent durability, particularly excellent wear resistance.

(Examples) Next, the present invention will be described more specifically with reference to examples and comparative examples. In the description, parts and% are based on weight unless otherwise specified.

Example 1 An ink containing the following three sublimable dyes having the following composition was prepared.

Yellow ink Disperse dye (Macrolex Yellow 6G, manufactured by Bayer AG, CI
Disperes Yellow 201) 5.5 parts Polyvinyl butyral resin (Eslec BX-1, manufactured by Sekisui Chemical) 4.5 parts Methyl ethyl ketone / toluene (weight ratio 1/1) 89.0 parts Magenta ink Magenta disperse dye (CIDisperse Red60)
Same as yellow ink except using.

Cyan Ink Dye (CISolvent Blue 63)
Same as yellow ink except using.

A heat-resistant slip layer (1 μm thick) is formed on the back surface of the ink composition by a gravure coating method, and an adhesion improving layer (0.5 μm thick) made of polyurethane resin is formed on the surface.
m) formed on the surface of a 6.0 μm thick polyester film (trade name “Lumirror” manufactured by Toray Industries, Inc.) (alternatively, a polyester film that has been subjected to a pre-adhesion treatment may be used instead). as an amount of about 3 g / m ^2, respectively yellow, Figure 5 sequentially face in the order of magenta and cyan b
As described above, coating and drying were repeated in a pattern to form a three-color sublimable dye layer. The above three colors were set as one set, and a space of 30 cm was provided between each set.

Next, use the ink of the following composition to fill the blank
It was applied and dried to form a release layer by gravure coating method on a solids basis in a pattern at a rate of 1 g / m ² as in Figure b.

100 parts of ink for release layer Acrylic resin 20 parts Methyl ethyl ketone 100 parts Toluene then applying and drying the following ink by the gravure coating method so as to the coating amount on the surface of the release layer is about 0.5 g / m ² heat A fusible ink layer was formed.

Hot-melt ink Acrylic / vinyl chloride / vinyl acetate copolymer resin 20
Part Carbon black 10 parts Toluene 35 parts MEK 35 parts Next, the following ink is applied to the uncoated portion of the base film in a pattern as shown in FIG. 5b at a rate of 1 g / m ^{2 based} on solid content and dried. A transfer protection layer was formed.

Protective layer ink Acrylic resin 20 parts Methyl ethyl ketone 50 parts Toluene 50 parts Polyethylene wax 1 part Next, on the surface of the heat-meltable ink layer and the transfer protective layer,
An ink having the following composition was applied in a pattern at a rate of 3 g / m ^{2 on} a solid basis and dried as shown in FIG. 5b to form an adhesive layer.

Adhesive layer ink Vinyl chloride / vinyl acetate copolymer 10 parts Methyl ethyl ketone 100 parts Toluene 100 parts Example 1 100 parts of polyvinyl chloride (polymerization degree 800) compound containing about 10% of additives such as stabilizers, white pigment (Titanium oxide) 10 parts and plasticizer (DOP) 0.5 part of the card base material, the sublimation dye layer of the thermal transfer sheet of the present invention is superimposed on the surface, and the electrical signal obtained by color separation of the face photograph is connected. By applying thermal energy with the thermal head, a full-color face photograph is formed on the gradation image forming area 22 of the card substrate 21 as shown in FIG. 2, and then letters and symbols are monotonously formed using a heat-meltable ink layer. The image was transferred to the image forming area 23, and the transfer protective layer was transferred to each image portion using a protective layer. Thus, a card having a face photograph and various necessary information was obtained.

Observation of the surface of the card revealed no black stain on the gradation image, no stain on the non-image portion, and 100% of the image portion with gauze impregnated with isopropyl alcohol. After rubbing it,
There was no change in the image and no gauze was contaminated.
On the other hand, when the protective layer was not transferred, the gauze was significantly contaminated with blackish brown.

Comparative Example 1 Using the inks of Example 1, a sublimable dye layer, a fusible ink layer and a transfer protective layer were formed in the same manner as the conventional thermal transfer sheet of FIG. 1 to obtain a thermal transfer sheet of Comparative Example. . When an image was formed using this thermal transfer sheet in the same manner as in Example 1, the color balance of the gradation image was remarkably distorted due to black. When the image portion was rubbed 100 times with gauze impregnated with isopropyl alcohol, the image portion did not change, but it was found that the gauze was darkly contaminated and the margin was contaminated.

[Brief description of the drawings]

FIG. 1 is a plan view of a conventional thermal transfer sheet, FIG. 2 is an example of a material to be transferred, and FIGS. 4a, 5, 6, 8, and 9 are plan views of the thermal transfer sheet of the present invention. FIG. 7 is a reference diagram, FIG. 10 is a diagram schematically illustrating a cross section of the thermal transfer sheet of FIG. 5b, and FIG. 11 is a card made of the thermal transfer sheet of FIG. 5b (FIG. 10). FIG. 3 is a diagram schematically illustrating a cross section of FIG. Y: Yellow thermal transfer layer M: Magenta thermal transfer layer C: Cyan thermal transfer layer Bk: Black thermal transfer layer 1: Base film, 2: Sublimable dye layer 3: Hot-melt ink layer, 4: Transfer protective layer 5: Release layer, 6: Heat-resistant lubricating layer 7: Adhesion improving layer, 8: Adhesive layer 9: Card substrate, 10: Color image 21: Transfer material 22: Gradation image forming area 23: Monotone image forming area

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B41M 5/38-5/40

Claims (6)

(57) [Claims] In a thermal transfer sheet comprising at least a sublimable dye layer and a hot-melt ink layer provided on a long base film in a face-to-face sequence, the sublimable dye layer and the hot-melt ink layer are transferred. A thermal transfer sheet, which is formed in a pattern at a position that does not overlap in an image forming area of a material. 2. The thermal transfer sheet according to claim 1, further comprising a transfer protection layer. 3. The thermal transfer sheet according to claim 2, wherein the transfer protective layer is formed on a base film corresponding to the image forming area of the material to be transferred. 4. The thermal transfer sheet according to claim 1, wherein a release layer is provided between the base film and the hot-melt ink layer. 5. The thermal transfer sheet according to claim 1, wherein the sublimable dye layer comprises a dye layer of at least three colors of yellow, magenta and cyan, and the heat-fusible ink layer comprises a black ink layer. 6. The thermal transfer sheet according to claim 1, which is for card making.