JP2003094845A - Thermal transfer sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal transfer sheet enabling easy preparation of a printed matter which has a metallic color being bright and having high luminance. SOLUTION: This thermal transfer sheet has a constitution wherein a lustrous layer 2 containing at least a pearl pigment and a metal thin film layer 3 are provided sequentially on the other side of a base film 1 provided with a heat- resistant layer 4, and the metal thin film layer 3 is formed of an aluminum pigment containing layer or an aluminum deposition layer. An aluminum pigment has an excellent hiding power and excellent reflectance properties and therefore can reproduce the metallic color of high luminance without being affected by the color of the ground of a transfer object almost at all. The pearl pigment of the lustrous layer 2 has optical properties such as regular multi-reflection and interference of light, though it is inferior considerably to the aluminum pigment in respect to the hiding power, and therefore it can produce a feel of bright metal luster.

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 in a thermal transfer printer using a heating means of a thermal head, and more specifically, it is possible to easily obtain a bright and bright printed matter having a metallic color. The present invention relates to a thermal transfer sheet.

[0002]

2. Description of the Related Art Conventionally, a thermal transfer sheet has been used in which a colored layer in which a colorant such as a pigment or a dye is dispersed in a hot-melt wax or a binder such as a resin is carried on a base material sheet such as a plastic film. A melt transfer method is known in which energy corresponding to image information is applied by a heating device such as a thermal head to transfer a colorant together with a binder onto an image receiving sheet such as paper or a plastic sheet.

A printed image formed by the melt transfer method has high density and excellent sharpness, and is suitable for recording binary images such as characters and line drawings. Further, by using a thermal transfer sheet having a color layer of yellow, magenta, cyan, black or the like and superimposing and recording each color layer on the image receiving sheet, it is possible to form a multicolor or full color image by subtractive color mixing. is there. Further, there is an increasing demand to obtain a printed matter having metallic luster and excellent in designability by utilizing such a melt transfer method. In response to the request, JP-A-1
0-16415 gazette etc., on one side of a base material,
A thermal transfer sheet having a metallic luster in which a vapor deposition anchor layer, a metal vapor deposition layer, and an adhesive layer are sequentially provided is presented.

[0004]

However, the printed matter using the thermal transfer sheet provided with the metal vapor deposition layer as described above has a high smoothness on the surface of the metal vapor deposition layer and has a high brightness. Since the sparkling effect is too high, there is a problem that the original tint of the colored layer is erased depending on the position of the light source and the viewing angle, resulting in a dark impression printed matter. Further, as the metal thin film layer, there is a printed matter using a thermal transfer sheet using a non-leafing type aluminum pigment, but in this case, since the smoothness of the surface of the metal thin film layer deteriorates, diffuse reflection components increase, Although it has a lighter shade, the sparkling effect is also reduced, and the brightness is insufficient.

Further, in the printed matter using the heat transfer sheet using the leafing type aluminum pigment, the reduction of the sparkling effect does not drop as much as that of the non-leafing type aluminum pigment type, so that the printed matter of relatively high brightness can be obtained. However, there was still the problem of a slightly dark impression remaining in terms of brightness. Therefore, an object of the present invention is to provide a thermal transfer sheet that can easily obtain a printed matter having a bright and high-luminance metallic color.

[0006]

In order to achieve the above object, the thermal transfer sheet of the present invention is provided with a heat-resistant layer on one surface of a base film and at least a pearl pigment on the other surface of the base film. The gloss layer and the metal thin film layer were sequentially provided. A colored layer is preferably provided between the substrate film and the metal thin film layer, and various tints can be added to the metal thin film layer of the obtained print. Also,
A colorant may be contained in the gloss layer. It is desirable that the metal thin film layer contains an aluminum pigment. Further, the metal thin film layer may be formed of a vapor deposited layer of aluminum. It is preferable that the metal thin film layer has a transmission density of 1.0 or more, which provides excellent concealing properties.

The operation of the present invention is as follows. The thermal transfer sheet of the present invention has a structure in which a gloss layer containing at least a pearl pigment and a metal thin film layer are sequentially provided on the other surface of the substrate film provided with a heat resistant layer, and the metal thin film layer is an aluminum pigment containing layer, Alternatively, it is formed by an aluminum vapor deposition layer. Since the aluminum pigment has excellent hiding power and reflection characteristics, it is possible to reproduce a high-luminance metallic color with almost no influence of the color of the base of the transferred material. on the other hand,
Although the pearl pigment is largely inferior to the aluminum pigment in hiding power, it has optical characteristics such as regular multiple reflection and light interference, and thus can express a bright metallic luster.
That is, by providing a metal thin film layer, it is possible to provide metal luster and concealment of the base, and by further providing a pearl luster layer, without significantly reducing the metal luster,
It is possible to reproduce a metallic color with brightness.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Next, embodiments of the present invention will be described in detail. The basic form of the thermal transfer sheet of the present invention is, as shown in FIG. 1, a heat-resistant layer 4 on one surface of a substrate film 1.
And a gloss layer 2 containing a pearl pigment and a metal thin film layer 3 are sequentially provided on the other surface of the base film 1. FIG. 2 shows one embodiment of the thermal transfer sheet of the present invention, in which a heat resistant layer 4 is provided on one surface of the base film 1, and a gloss containing a pearl pigment on the other surface of the base film 1. The layer 2, the coloring layer 5, and the metal thin film layer 3 are sequentially provided. FIG. 3 shows another embodiment of the thermal transfer sheet of the present invention, in which a heat resistant layer 4 is provided on one surface of a base film 1, and a colored layer 5 and a pearl pigment are provided on the other surface of the base film 1. The glossy layer 2 containing the metal and the metal thin film layer 3 are sequentially provided. Other than those shown, if necessary, for example,
An adhesive layer can be provided or a layer can be added on the metal thin film layer.

(Base Material Film) As the base material film 1 used in the present invention, the same base material film as that used in the conventional thermal transfer sheet can be used as it is, and other materials can also be used. , Not particularly limited. Specific examples of the preferable substrate film include, for example, polyester, polypropylene, cellophane, polycarbonate, cellulose acetate, polyethylene, polyvinyl chloride, polystyrene, nylon, polyimide, polyvinylidene chloride, polyvinyl alcohol, fluororesin, chlorinated rubber, ionomer and the like. , Such as plastic films, condenser paper, paraffin paper, and non-woven fabrics,
Further, it may be a base film which is a composite of these. A particularly preferred substrate film is a polyethylene terephthalate film. The thickness of this substrate film can be appropriately changed depending on the material so that its strength and thermal conductivity are appropriate, but its thickness is preferably, for example, 2 to 25 μm.

(Gloss Layer) In the thermal transfer sheet of the present invention, a gloss layer 2 containing a pearl pigment is formed between the base film and the metal thin film layer. This glossy layer improves the releasability of the metal thin film layer from the base material film during thermal transfer, and after transfer, at least part of it is transferred together with the metal thin film layer onto the surface of the transferred image to protect the metal thin film layer and provide gloss and brightness. It also functions as a layer for imparting a thickness, and can also improve the scratch resistance of the transferred image. Further, by adding a colorant to the gloss layer, it is possible to add tint and gloss to the metal thin film layer of the obtained print. Therefore, since the gloss layer is located on the metal thin film layer in the state of the transferred image, it has transparency and smoothness to the extent that the metal surface of the metal thin film layer can be seen through.

As a binder constituting this glossy layer,
For example, acrylic resin, olefin resin, styrene resin, ethylene-vinyl acetate copolymer resin, vinyl chloride-vinyl acetate copolymer resin, polyester resin, cellulose resin, polyvinyl acetal resin, polyvinyl butyral resin, silicone resin, fluorine resin, silicone Alternatively, various kinds of resins modified with fluorine, such as homopolymers or mixtures, copolymers,
In addition to this, wax or the like can be added to adjust the releasability and slipperiness. Particularly, in terms of releasability and resolution, Tg for adjusting the adhesiveness between the binder resin having a high releasability and a Tg of 100 ° C. or more and the resolving ability or the base film is about 60 to 100 ° C. A system in which the binder resin is mixed is preferable, and it is more preferable to include a binder resin of the same type as the binder resin used in the metal thin film layer. For example, a system in which an acrylic resin having a Tg of 100 ° C. or more as a main component and a vinyl chloride-vinyl acetate copolymer resin having a Tg of about 60 to 100 ° C. is mixed is preferable in terms of transparency.

As the wax, various waxes which are melted at the time of printing and exhibit peelability are preferable. Suitable waxes include, for example, microcrystalline wax, carnauba wax, paraffin wax, Fischer-Tropsch wax, various low-molecular-weight polyethylenes, wood wax, beeswax, spermaceti wax, ivowa wax,
Wool wax, shellac wax, candelilla wax,
Petrolactam, partially modified wax, fatty acid ester,
Various waxes such as fatty acid amides may be mentioned. Particularly preferred waxes are microcrystalline wax and carnauba wax, which have a relatively high melting point and are difficult to dissolve in a solvent.

As the pearl pigment contained in the gloss layer, those conventionally used such as natural pearl essence, mercury chloride, basic lead carbonate, bismuth acid chloride and mica can be used, and particularly natural mica having a low refractive index. It is preferable that the surface of (mica) is coated with a metal oxide having a high refractive index, and the light reflected by utilizing the difference in the refractive index between natural mica and the metal oxide brings pearly luster. As the metal oxide, titanium oxide and iron oxide are preferably used because of their glossiness and refractive index. The pearl pigment is scale-like and has a particle size of 0.0
One having a particle size of 1 to 500 μm and a particle thickness of 0.05 to 1.0 μm is used, and a particle size of 1.0 to 25 μm is preferably used. Further, the gloss layer may contain a coloring agent such as a dye or a pigment, and the hue inherent to the pearl pigment contained in the gloss layer may be changed to another hue to further improve the decorative property. As the above-mentioned colorant, conventionally known colorants such as dyes and pigments can be used alone or in any combination. Specifically, for example, carbon black,
Nigrosine Dye, Lamp Black, Sudan Black SM, Alkali Blue, First Yellow G, Benzidine Yellow, Pigment Yellow, India First Orange, Irgadine Red, Paranitroaniline Red, Toluidine Red, Carmine FB, Permanent Bordeaux FRR, Pigment Orange R, Resor Red 20, Rake Red C, Rhodamine FB,
Rhodamine B Lake, Methyl Violet B Lake,
Phthalocyanine Blue, Pigment Blue, Brilliant Green B, Phthalocyanine Green, Oil Yellow GG, Zaboon First Yellow CGG, Kayaset Y963, Kayaset YG, Sumiblast Yellow GG, Zaboon First Orange RR, Oil Scarlet, Smiblast Orange G, Orazol. Brown B, Pomelo First Scarlet CG, Eisenspiron Red BEH, Oil Pink OP, Victoria Blue F4R, First Gen Blue 5007, Sudan Blue, Oil Peacock Blue and the like.

The gloss layer contains a pearl pigment and, if necessary, an additive such as a colorant, in an amount of 90 to 20% by weight and a binder of 80 to 10% by weight based on the total solid content of the gloss layer. It is preferable to use the ink composition mixed in the ratio of. When the amount of the pearl pigment is less than the above range, the coating amount must be increased in order to obtain the glossiness, resulting in insufficient printing sensitivity and resolution. On the other hand, if the pearl pigment is more than the above range, flexibility and film-forming property cannot be obtained, which may cause a decrease in sensitivity, a foil drop, and a scratch resistance of a printed matter. Further, the content of the colorant can be arbitrarily selected in consideration of not completely hiding the underlying metal thin film layer upon transfer and not impairing the brightness of the printed matter.

When the metal thin film layer is formed of an aluminum vapor deposition layer, the gloss layer can function as a vapor deposition anchor layer. That is, it is to provide a base for vapor deposition of metal and to protect the base film and the like from heat during vapor deposition. Also, after transfer printing, it is transferred to the transfer target together with the aluminum vapor deposition layer, and it is located above the vapor deposition layer and adheres to the vapor deposition layer to become a component of the recorded matter, and the vapor deposition layer is mechanically scratched or corroded. And also functions as a protective layer for improving chemical strength. Further, when the gloss layer contains a colorant, the peelability from the substrate may not be stable depending on the pigment content. Therefore, in order to stabilize the peelability, the release layer and the colorant are contained. It is also possible to have a two-layer structure of a gloss layer that does not. The glossy layer is a thin layer, for example, in a dry state, such as 0. 0, by a conventionally known method such as gravure direct coating, gravure reverse coating, knife coating, air coating or roll coating so as not to reduce the sensitivity of the thermal transfer sheet. A thickness of about 1 to ² g / m ² is preferable.

(Metal thin film layer) In the thermal transfer sheet of the present invention, the metal thin film layer 3 is formed of a layer containing an aluminum pigment or an aluminum vapor deposition layer. The metal thin film layer as the aluminum pigment-containing layer is a scale-like aluminum pigment, an aluminum pigment such as a non-leafing type aluminum pigment,
Further, a binder and, if necessary, various additives such as a colorant, a dispersant, and an antistatic agent can be added.

The scaly aluminum pigment can be manufactured by the following method. 1. A release layer is formed on a roll-shaped or continuous carrier sheet. 2. Aluminum is deposited on the release layer by a vapor deposition method to form an aluminum film. 3. The release layer is melted or peeled from the substrate to separate the aluminum coating and the carrier sheet from each other. 4. The separated aluminum film is subdivided into dimensions suitable for use in a coating ink. The scale-like aluminum pigment produced as described above has a vapor deposition thickness of about 0.01 to 0.1 μm, an average diameter of about 5 to 50 μm, and is scale-like.
The surface may be treated with resin or the like. The scale-like aluminum pigment produced by the above-described production method has a slower settling speed because its thickness is thinner and lighter than conventional aluminum pastes, and the surface side of the coating film by slowing the drying speed during ink coating ( Can be oriented almost uniformly in the upper side). Further, since the smoothness of the aluminum flat surface is the same as that of the vapor deposition film, a brightness close to that of the aluminum vapor deposition film can be obtained.

Since the non-leafing type aluminum pigment has a small surface tension and a strong affinity with solvents and paints, it may settle on the back surface (lower side) of the coating film or may be dispersed in the coating film, resulting in non-uniformity. Tends to orient. Aluminum pigment to be contained in the metal thin film layer, as the final print, brightness, brightness,
Considering the metallic luster and the concealment of the transferred material's undercoat, etc., a scale-like aluminum pigment is used in combination with a non-leafing type aluminum pigment, or only a scale-like aluminum pigment is used, or only a non-leafing type aluminum pigment is used. It can be used.

The metal thin film layer as the aluminum pigment-containing layer uses a binder for holding the aluminum pigment such as the scale-like aluminum pigment and the non-leafing type aluminum pigment. As the binder, it is preferable to mainly configure a resin, and specifically, as the resin, a cellulose resin, a melamine resin, a polyester resin, a polyamide resin, a polyolefin resin, an acrylic resin, a styrene resin, Ethylene-vinyl acetate copolymer, vinyl chloride-vinyl acetate copolymer resin, styrene-
Examples thereof include thermoplastic elastomers such as butadiene rubber. Particularly, those having a relatively low softening point, which has been conventionally used as a heat-sensitive adhesive, for example, a softening point of 50 to 150 ° C. are preferable. Among the resins used as a binder, acrylic resin, polyester resin, acrylic resin, polyester resin, in particular in terms of transferability, scratch resistance, heat resistance, adhesion to the gloss layer, etc.
Cellulose resins and vinyl chloride-vinyl acetate copolymer resins are preferably used alone or as a mixture.

In addition, if necessary, a wax component may be mixed and used to the extent that heat resistance and the like are not impaired. Examples of waxes include microcrystalline wax, carnauba wax, and paraffin wax. In addition, Fischer-Tropsch wax, various low molecular weight polyethylene, wood wax, beeswax, spermaceti wax, ivowa wax, wool wax, shellac wax, candelilla wax, petrolactam, polyester wax, partially modified wax, fatty acid ester, fatty acid amide, etc. Wax. Among them, especially the melting point is 50
What is -85 degreeC is preferable. When the temperature is 50 ° C or lower,
There is a problem in storability, and if the temperature is 85 ° C or higher, the printing sensitivity becomes insufficient.

The metal thin film layer is prepared by adding each pigment such as a scale-like aluminum pigment and a non-leafing type aluminum pigment and, if necessary, various additives to the solid thin film layer in an amount of 90 to It is preferable to use an ink composition in which 20% by weight and a binder of 80 to 10% by weight are mixed. When the amount of the pigment is less than the above range, the coating amount must be increased in order to obtain the density, resulting in insufficient printing sensitivity. Further, when the amount of the pigment is more than the above range, the film forming property cannot be obtained, which causes a decrease in scratch resistance after printing. When using a combination of scaly aluminum pigments and non-leafing type aluminum pigments, the mixing ratio cannot be unequivocally stated because it depends on the hiding property to be set, glossiness, brightness, and the coating amount of the metal thin film layer. The hiding property is preferably set so that the transmission density of the metal thin film layer is 1.0 or more.

This transmission density is defined as follows. It is an amount showing the degree to which a given substance layer (metal thin film layer) absorbs light, and has the same meaning as the absorbance. The higher the value, the greater the amount of light absorption (it is difficult to transmit light).
The absorbance As can be expressed by the following equation when the intensity of light changes from Io to I due to absorption while passing through the material layer. As = log ₁₀ (Io / I) As for the transmission density, visible light is used as measurement light by a spectrophotometer.

The formation of the metal thin film layer as the aluminum pigment-containing layer is carried out by adding the above-mentioned scale-like aluminum pigment, non-leafing type aluminum pigment, various additives as necessary, a binder component, and an organic solvent. A coating solution for forming a metal thin film layer in which solvent components such as are mixed and adjusted are conventionally known gravure direct coat, gravure reverse coat,
A thickness of 0.1 to 5 g / m ² , preferably 0.3 to 1.5 g / m ² is provided in a dried state by a method such as knife coating, air coating, and roll coating. When the thickness of the dry coating film is less than 0.1 g / m ² , sufficient hiding property cannot be obtained, and when the thickness exceeds 5 g / m ² , high energy is not generated during print transfer. It becomes necessary and the resolution is lowered, and there is a problem that it can be printed only by a special thermal transfer printer.

The metal thin film layer formed by aluminum vapor deposition is a metallizing method under vacuum such as vacuum vapor deposition and sputtering of aluminum alone or an alloy of aluminum and another metal. The thickness of the aluminum vapor deposition layer is usually 100 to 1000Å, preferably 200 to 600Å
The undercoating property of the transferred material is sufficient, and the transmission density of the metal thin film layer can be 1.0 or more. If the thickness of the vapor-deposited aluminum layer is too thin, partial unevenness may occur, resulting in pinholes or the like. On the other hand, if it is too thick, the foil breaks during printing, the resolution of the printed matter is poor, and it is uneconomical.

(Coloring Layer) In the thermal transfer sheet of the present invention, a coloring layer 5 is provided between the base film and the metal thin film layer,
Various tints can be added to the metal thin film layer of the obtained print. Also, when the specific gravity of the pearl pigment and the colorant is significantly different when the colorant is contained in the glossy layer, there is a difference in the ratio of pigments transferred during coating, which causes a problem that the color tone is not stable, and thus the color developability is improved. In order to make it more stable, it is also possible to have a two-layer structure of a colored layer and a gloss layer containing no coloring agent. The positional relationship between the colored layer and the gloss layer containing the pearl pigment may be base film / gloss layer / colored layer / metal thin film layer in the order of base film / colored layer / gloss. The layers / metal thin film layers may be provided in this order, or any of them may be provided. The colored layer is composed of a binder made of a resin, wax or a mixture thereof, and a conventionally known coloring agent such as a dye or a pigment alone or in an arbitrary combination. As the resin used for the binder, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer or other polyolefin resin, polyamide resin, polyester resin, epoxy resin, polyurethane resin, acrylic resin, polychlorinated resin Examples thereof include vinyl resins, polyvinyl acetate resins, petroleum resins, phenol resins, polystyrene resins and the like. As the wax used for the binder, microcrystalline wax, carnauba wax, paraffin wax, Fischer-Tropsch wax, various low molecular weight polyethylene, wooden wax, beeswax, spermaceti wax, ivota wax, wool wax, shellac wax, candelilla wax, petrolactam, Various waxes such as partially modified wax, fatty acid ester, and fatty acid amide can be used.

As the colorant, conventionally known colorants such as dyes and pigments can be used alone or in any combination. Specific colorants are the same as those described for the gloss layer. Can be used. The content of the colorant in the colored layer can be arbitrarily selected in consideration of not completely hiding the underlying metal thin film layer when transferred, and not impairing the brightness of the printed matter. It is preferably contained in a proportion of 3 to 100 parts by weight with respect to 100 parts by weight of the binder. The colored layer is preferably a thin layer, for example, a thickness of about 0.1 to ² g / m ^{2 in} a dried state by a conventionally known method such as gravure direct coating, gravure reverse coating, knife coating, air coating, and roll coating. If the thickness is too large, there is a problem that the transfer sensitivity is lowered and good printing cannot be obtained. Further, if the thickness is too small, the coloring property will be deteriorated.

(Heat-Resistant Layer) In the present invention, a heat-resistant layer 4 is provided on the surface of the substrate film in contact with the thermal head in order to improve the slipperiness of the thermal head and prevent sticking. It is preferable. The heat-resistant layer contains a heat-resistant resin and a substance acting as a thermal release agent or a lubricant as basic constituent components. By providing such a heat-resistant layer, thermal printing can be performed without sticking even on a thermal transfer sheet using a plastic film that is weak against heat as a base material. You can take advantage of such advantages.

This heat-resistant layer comprises a binder resin, a slip agent, and
It is formed by suitably using a material to which a surfactant, inorganic particles, organic particles, a pigment, etc. are added. The binder resin used in the heat-resistant layer is, for example, cellulose-based resin such as ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, cellulose acetate, cellulose acetate butyrate, nitrified cotton, polyvinyl alcohol, polyvinyl acetate, polyvinyl butyral, polyvinyl acetal. , Vinylpyrrolidone, acrylic resin, polyacrylamide, vinyl resin such as acrylonitrile-styrene copolymer, polyester resin, polyurethane resin, silicone-modified or fluorine-modified urethane resin, and the like.

Of these, those having several reactive groups, for example, those having a hydroxyl group, are used as a cross-linking agent.
It is preferable to use a crosslinked resin in combination with polyisocyanate or the like. The means for forming the heat-resistant layer is a coating liquid prepared by dissolving or dispersing a material obtained by adding a lubricant, a surfactant, inorganic particles, organic particles, a pigment, etc. to the binder resin as described above in a suitable solvent. Is prepared, and the coating solution is applied and dried by a conventional coating means such as a gravure coater, a roll coater, and a wire bar. The heat-resistant layer has a thickness of 0.01 to 3 g / m in a dry state.
^{About 2} is preferable.

(Adhesive Layer) In the thermal transfer sheet of the present invention, an adhesive layer may be provided on the metal thin film layer in order to improve transferability. The adhesive layer can improve the adhesiveness between the image receiving sheet and the metal thin film layer to be transferred. This adhesive layer is
Due to the heating of the thermal head, a thermoplastic resin that softens and exhibits adhesiveness is the main component, and in order to prevent blocking when the resulting thermal transfer sheet is wound into a roll, waxes, amides of higher fatty acids, esters and An antiblocking agent can be added, such as salt, fluororesin or inorganic substance powder.

As the thermoplastic resin, for example, ethylene-
Vinyl acetate copolymer (EVA), ethylene-acrylic acid ester copolymer, polyester resin, polypropylene, petroleum resin, vinyl chloride resin, vinyl chloride-vinyl acetate copolymer, acrylic resin, polyamide, polyvinyl butyral, polyvinyl acetate , And the like, and those having a relatively low softening point conventionally used as a heat-sensitive adhesive, for example, a softening point of 50 to 150 ° C. are preferable.
Further, in order to enhance the transfer sensitivity and the transferability to rough paper or the like having a low surface smoothness, the adhesive layer may be mainly composed of the wax component as described above.

To form the adhesive layer, the above-mentioned thermoplastic resin and additives are hot-melt coated or a coating solution for forming an adhesive layer, which is dissolved or dispersed in a suitable organic solvent or water, is used in a conventionally known hot-melt coating or hot-melt coating. By lacquer coat, gravure direct coat, gravure reverse coat, knife coat, air coat, roll coat, etc.,
A thickness of 0.05 to 5 g / m ² is provided in a dry state. When the thickness of the dry coating film is less than 0.05 g / m ² , the adhesiveness between the transferred material and the metallic layer is poor, and transfer failure occurs during printing. On the other hand, if the thickness exceeds 5 g / m ² , resolution and transfer sensitivity at the time of printing are lowered, and satisfactory printing quality cannot be obtained.

The thermal transfer sheet of the present invention includes rough paper such as Kent paper, medium quality paper, high quality paper, art paper, lightweight coated paper, lightly coated paper, coated paper, cast coated paper, synthetic resin or emulsion impregnated paper, Synthetic rubber latex-impregnated paper, synthetic resin internal-addition paper, synthetic paper, plastic sheet, and the like, or a laminate obtained by combining them can be used as the transfer target. Further, a so-called label, which is obtained by subjecting the back surface of the base material of the transferred material to an adhesive treatment and pasted with a release sheet, can be used as the transferred material.

[0034]

EXAMPLES Next, the present invention will be described more specifically with reference to Examples and Comparative Examples. In the text, "part" or "%" means
Unless otherwise specified, it is based on weight. (Example 1) As a substrate film, a coating liquid for a gloss layer having the following composition was gravure coated on one surface of a polyethylene terephthalate film having a thickness of 6.0 μm.
A glossy layer is formed by coating and drying so that the dry coating amount is 0.9 g / m ² . Further, a coating solution for metal thin film layer having the following composition was applied onto the glossy layer by gravure coating so that the dry coating amount was 0.6 g / m ² , and dried to form a metal thin film layer, The thermal transfer sheet of Example 1 is prepared. On the other surface of the above-mentioned substrate film, a heat-resistant layer coating solution having the following composition was previously applied by gravure coating so that the dry coating amount was 0.3 g / m ² , and the heat-resistant layer was dried. Is formed.

[0035] [Coating liquid for glossy layer]   Pearl pigment 2 parts (Merck Japan KK IRIOZIN 111)   Colorant (Pigment Red 122) 2 parts   Acrylic resin (Tg: 105 ° C) 12 parts   Methyl ethyl ketone 42 parts   42 parts of toluene

[0036] [Coating liquid for metal thin film layer]   Scale-like aluminum pigment 4 parts (Made by Avery Dennison, product name: Metalure)   Acrylic resin (Tg: 105 ° C) 4 parts   40 parts of toluene   Methyl ethyl ketone 40 parts   Propylene glycol monomethyl ether 10 parts

[0037] [Heat-resistant coating liquid]   Styrene acrylonitrile copolymer resin 11 parts   Linear saturated polyester resin 0.3 parts   Zinc stearyl phosphate 6 parts   Melamine resin powder 3 parts   Methyl ethyl ketone 80 parts

(Example 2) A colored layer having the following composition was gravure-coated on the same substrate film as the heat-resistant layer used in Example 1 to give a dry coating amount of 0.6 g.
After coating and drying so as to / m ^2, coated with a gloss layer coating solution having the following composition so as to have a dry coating amount by gravure coating is 1.0 g / m ^2, and dried to form a glossy layer. Further, a metal thin film layer coating solution having the following composition was applied onto the glossy layer by gravure coating so that the dry coating amount was 0.7 g / m ² , and dried to form a metal thin film layer. The thermal transfer sheet of Example 2 is prepared.

[0039] [Coating liquid for colored layer]   Colorant (Pigment Red 122) 2 parts   Acrylic resin (Tg: 105 ° C) 12 parts   Methyl ethyl ketone 42 parts   42 parts of toluene

[0040] [Coating liquid for glossy layer]   Pearl pigment 2 parts   (Merck Japan KK IRIOZIN 111)   Acrylic resin (Tg: 105 ° C) 12 parts   Methyl ethyl ketone 42 parts   42 parts of toluene [Coating liquid for metal thin film layer]   Scale-like aluminum pigment 3 parts (Made by Avery Dennison, product name: Metalure)   Non-leafing type aluminum pigment 1 part   Acrylic resin (Tg: 105 ° C) 4 parts   40 parts of toluene   Methyl ethyl ketone 40 parts   Propylene glycol monomethyl ether 10 parts

(Example 3) The same composition as the base film with heat-resistant layer used in Example 1 was coated with a coloring layer having the following composition by gravure coating to give a dry coating amount of 0.8 g /
After coating and drying so as to have a thickness of m ² , the gloss layer coating liquid having the following composition was gravure coated to give a dry coating amount of 0.
The glossy layer is formed by coating so as to be 5 g / m ² and drying. Furthermore, on the glossy layer, a metal thin film layer is formed by an aluminum vapor deposition layer having a film thickness of 350Å by a vacuum vapor deposition method,
An adhesive layer having the following composition was applied by gravure coating so that the dry coating amount was 0.5 g / m ² , and dried to prepare a thermal transfer sheet of Example 3.

[0042] [Coating liquid for colored layer]   Colorant (red dye) 1 part   Acrylic resin (Tg: 105 ° C) 12 parts   Methyl ethyl ketone 42 parts   42 parts of toluene

[0043] [Coating liquid for glossy layer]   Pearl pigment 12 parts (Merck Japan KK IRIOZIN 111)   Acrylic resin (Tg: 105 ° C) 12 parts   Methyl ethyl ketone 38 parts   Toluene 38 parts

[0044] [Coating liquid for adhesive layer]   Vinyl chloride-vinyl acetate copolymer resin (Tg: 70 ° C) 20 parts   40 parts of toluene   Methyl ethyl ketone 40 parts

Comparative Example 1 A colored layer having the following composition was gravure-coated on the same base film as the heat-resistant layer used in Example 1 to give a dry coating amount of 0.9 g.
/ M ² and then dried, and then the other example 1
A metal thin film layer was formed in the same manner as in 1. to prepare a thermal transfer sheet of Comparative Example 1.

[0046] [Coating liquid for colored layer]   Colorant (Pigment Red 122) 2 parts   Acrylic resin (Tg: 105 ° C) 12 parts   Methyl ethyl ketone 42 parts   42 parts of toluene

Comparative Example 2 A colored layer and a metal thin film layer were formed in the same manner as in Example 2 except that the gloss layer was not provided on the same base film as the heat-resistant layer used in Example 2 above. After being formed, a thermal transfer sheet of Comparative Example 2 was produced.

(Comparative Example 3) A metallic thin film layer and an adhesive layer were formed in the same manner as in Example 3 except that the gloss layer was not provided on the colored layer in Example 3 described above, and a comparative example 3 was obtained. A thermal transfer sheet was produced.

Using the thermal transfer sheets of the above Examples and Comparative Examples, printing was performed under the following printing conditions, and the printed matter was evaluated for glossiness, hiding power and brightness by the following evaluation methods. I do. (Printing conditions) Commercially available sublimation printer (resolution 300 dp
By using i), a dedicated thermal transfer image-receiving sheet with a photographic image previously printed on one side thereof is used as the transfer target, and a test pattern is printed using the thermal transfer sheets of Examples and Comparative Examples, and evaluation is performed. I made a sample.

(Glossiness Evaluation Method) Under the above printing conditions, the printed matter obtained was visually evaluated for metal glossiness. The evaluation was made according to the following criteria. ◯: The metallic luster is high and the appearance is good. Δ: The metallic luster is not so high and the appearance is not so good. X: The metallic luster is low and it does not look good.

(Evaluation Method of Concealability) With respect to the printed matter obtained under the above-mentioned printing conditions, it is visually inspected whether or not the photographic image located on the base can be seen through, and the concealability is evaluated. The evaluation was made according to the following criteria. ◯: The photographic image located on the background is not transparent and is not visible, and the image is excellent in concealment. Δ: An image in which the photographic image located on the background is slightly transparent and slightly different from the hue of the original metallic layer, and the hiding property is slightly insufficient. ×: The photographic image located on the background can be clearly seen through
The hue of the image looks quite different from the hue of the original metallic layer, and the image has very poor hiding power.

(Brightness Evaluation Method) Under the above printing conditions, it is examined whether the printed matter obtained looks dark by changing the viewing angle, and the brightness is evaluated. The evaluation was made according to the following criteria. ○: It looks bright in a wide range of angles. Δ: It becomes darker when the viewing angle is closer to parallel to the printed matter. X: It looks almost dark except when viewed at a certain angle.

Further, in the thermal transfer sheets prepared in the above Examples and Comparative Examples, the light transmission density of only the metallic thin film layer under the conditions of the coating liquid composition and the coating thickness of the metallic thin film layer of the thermal transfer sheet of each example was measured. , Macbeth transmission densitometer TR-9
At 24, a transmission density of the metal thin film layer was measured by using a status Blue filter.

(Evaluation Results) The above evaluation results are shown in Table 1 below.
Shown in.

[Table 1]

[0055]

As described above, the thermal transfer sheet of the present invention has a structure in which a glossy layer containing at least a pearl pigment and a metal thin film layer are sequentially provided on the other surface of the base film provided with the heat resistant layer. The metal thin film layer is formed of an aluminum pigment-containing layer or an aluminum vapor deposition layer. Aluminum pigments have excellent hiding power and reflection characteristics, so
Highly bright metallic colors can be reproduced almost without being affected by the color of the base of the transferred material, and the pearlescent pigment of the gloss layer is much inferior to the aluminum pigment in hiding power, but regular multiple reflection and light interference. With such optical characteristics, a bright metallic luster can be expressed. Therefore, by providing a metal thin film layer, it has metallic luster and concealment of the base, and by further providing a pearl luster layer, a metallic color with brightness is reproduced without significantly reducing metallic luster. It becomes possible to do.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an example of a basic form of a thermal transfer sheet of the present invention.

FIG. 2 is a schematic cross-sectional view showing one embodiment of the thermal transfer sheet of the present invention.

FIG. 3 is a schematic cross-sectional view showing another embodiment of the thermal transfer sheet of the present invention.

[Explanation of symbols]

1 Base film 2 gloss layer 3 Metal thin film layer 4 Heat-resistant layer 5 colored layers

Claims (6)

[Claims] 1. A thermal transfer sheet comprising a heat resistant layer provided on one side of a base film, and a gloss layer containing at least a pearl pigment and a metal thin film layer provided on the other side of the base film in this order. . 2. The thermal transfer sheet according to claim 1, wherein a colored layer is provided between the base film and the metal thin film layer. 3. The thermal transfer sheet according to claim 1, wherein the gloss layer contains a colorant. 4. The thermal transfer sheet according to claim 1, wherein the metal thin film layer contains an aluminum pigment. 5. The thermal transfer sheet according to claim 1, wherein the metal thin film layer is formed of a vapor deposition layer of aluminum, and an adhesive layer is provided on the vapor deposition layer. . 6. The thermal transfer sheet according to claim 1, wherein the metal thin film layer has a transmission density of 1.0 or more.