JP2001191624A - Thermal transfer sheet - Google Patents

Abstract

(57) [Summary] [Problem] Even when subjected to high heat by a thermal head, when a printed material is formed, a fine crack is formed in a metal deposition layer to form a mat, and the metallic gloss feeling is not impaired, and excellent metallic gloss is obtained. The present invention provides a thermal transfer sheet capable of forming a print having the following. SOLUTION: At least one release anchor layer, a metal deposition layer and an adhesive layer are sequentially provided on one surface of a film substrate, and the release anchor layer has an elastic modulus of 1 at 150 ° C.
0 containing ⁶ Pa or more resins mainly, 50 is adhesive layer
Wax having a melting point of 120 ° C. or softening point and / or
Or, by mainly containing a thermoplastic resin, the adhesive layer can be melted and transferred to the transfer target in a temperature range in which the release anchor layer is not deformed, so that a printed matter having excellent metallic luster by thermal transfer with a thermal head or the like. Is obtained.

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 for printing characters and designs having a metallic feeling such as metallic luster on a material to be transferred by a thermal transfer recording system. In particular, the present invention relates to a thermal transfer sheet excellent in metallic luster without being affected by high heat at the time of printing by a thermal printer.

[0002]

2. Description of the Related Art Conventionally, as a method for obtaining a printed matter having a metallic luster, there has been known a hot stamping method in which a transfer foil is used to hot-press with a stamp made of metal or the like having a convex portion having the same shape as the printed matter. ing. As this transfer foil, for example,
A layer obtained by sequentially laminating a release layer, a vapor deposition anchor layer, a metal vapor deposition layer, and an adhesive layer on a base film of about 9 to 25 μm is used. Then, the desired image is transferred to the transfer object by pressing the adhesive layer side of the transfer foil against the transfer object such as paper and pressing the stamp heated to about 100 to 130 ° C. for several seconds from the base film side. This is an image recording method to be performed. However, the hot stamping method is not suitable for printing a small number of copies because it is necessary to produce a stamp made of metal or the like each time. In addition, precision processing such as halftone dots is required, and recording of a fine halftone image is difficult.

On the other hand, in recent years, a thermal transfer recording system using a thermal head and a thermal transfer ribbon has become widespread.
This method is suitable for printing a small number of copies and can easily record a halftone image by area gradation. Therefore, a transfer recording method using a thermal head instead of the stamp is desired. For example, JP-A-63-30288
In Japanese Patent Application Laid-Open Publication No. H11-115, an attempt has been made to thermally transfer a transfer foil used in a conventional hot stamping method using a thermal head using a thinner base film.

[0004]

However, a resin such as an acrylic resin, a urethane resin, or a cellulose resin is used for the deposition anchor layer of the transfer foil used in the conventional hot stamping method. . For this reason, if a transfer foil using these resins as is is used for transfer with a thermal head, the metal deposition layer becomes matte (fogged) at the time of printing, and a recorded matter having a metallic luster of specular gloss can be obtained. Can not.

[0005] This is a thermal transfer method using a thermal head and a thermal transfer method using a hot stamping method.
This occurs due to the difference in the process of applying thermal energy. That is, in the hot stamping method, 9 to
A recorded matter is obtained by pressing a stamp heated to about 100 to 130 ° C. from the back of the base film having a thickness of 25 μm for several seconds. On the other hand, in the thermal transfer method using a thermal head, the thermal head is pressed against the back surface of a base film having a thickness of 3 to 6 μm, and the surface of the thermal head is raised to about 300 ° C. for several to several tens of milliseconds. By doing so, a recorded matter is obtained. Therefore, even when heat energy loss is taken into consideration, the deposition anchor layer formed on the base film is heated to at least about 130 to 200 ° C. At this time, if the above-described resin is used as the vapor deposition anchor layer, the vapor deposition anchor layer is elastically deformed or plastically deformed because the vapor deposition anchor layer is heated to a temperature equal to or higher than the glass transition temperature and further applied with pressure. For this reason, the metal deposition layer, which had a mirror surface formed on the deposition anchor layer, follows the deformation of the deposition anchor layer, causing irregularities or fine cracks in the halftone dot pattern of the heating part of the thermal head, and The flatness of the printed matter is lost, and as a result, the metal deposited layer is matted in the recording material transferred and formed on the transfer target body, and light is scattered on the surface of the transferred metal deposited layer, and the printed matter is matted, and The commercial value of a print that should have gloss is reduced.

[0006] By the way, the transfer foil contains two liquids or one liquid.
In some cases, a liquid-curable resin is used for the deposition anchor layer, applied to the surface of the substrate film, and then thermally cured to increase the glass transition temperature. However, transfer foils made by these methods do not cause the problem of matting as described above. However, since the pot life during coating is short, and the curing conditions are high temperature and long time, a thin film base material used for thermal transfer is used. There is a problem that it is not suitable for coating on a film.

Therefore, to solve the above problem,
The present invention provides a printed material having excellent metallic luster without being affected by high cracks caused by fine cracks in a metal vapor deposited layer when formed into a printed material even when subjected to high heat by a thermal head. It is an object to provide a heat transfer sheet that can be formed.

[0008]

Means for Solving the Problems To achieve the above object, the thermal transfer sheet of the present invention comprises, on one surface of a film substrate, at least a release anchor layer, a metal deposition layer and an adhesive layer, which are sequentially provided. The release anchor layer mainly contains a resin having an elastic modulus of 10 ⁶ Pa or more at a glass transition temperature of 150 ° C., and the adhesive layer has a melting point of 50 to 120 ° C. or a wax and / or a thermoplastic resin having a softening point. Is mainly contained.

[0009] The resin of the release anchor layer is characterized in that it is at least one selected from chlorinated polyolefin resin, polyarylate resin and norbornene-based hydrogenated resin. Further, the chlorinated polyolefin resin has a chlorination degree of 50% or more and a mass average molecular weight of 5,000.
0 to 250,000. By adopting the above configuration, the adhesive layer can be melted and transferred to the object to be transferred in a temperature range where the release anchor layer is not deformed, so that a printed matter having excellent metallic luster by thermal transfer using a thermal head or the like can be obtained. That is, by setting the elastic modulus at 150 ° C. of the resin contained in the release anchor layer to be 10 ⁶ or more, even when the adhesive layer is at or above the transfer temperature and is softened and melted, the release anchor layer is Without following the deformation, the flatness of the deposited layer can be maintained,
A printed matter excellent in glossiness can be obtained.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail with reference to preferred embodiments. FIG. 1 is a longitudinal sectional view showing one embodiment of the thermal transfer sheet having metallic luster of the present invention. In the thermal transfer sheet 1 shown in the figure, a heat-resistant layer 6 is provided on the back side of a film substrate 2, and on the front side of the film substrate 2, a release anchor layer 3, a metal deposition layer 4, an adhesive layer 5 is provided. Note that the heat-resistant layer 6 can be omitted as appropriate in some cases. In addition, the thermal transfer sheet of the present invention is usually used as a continuous belt-like thermal transfer sheet, but may be used as a single sheet.

Hereinafter, each layer of the thermal transfer sheet of the present invention will be sequentially described. (Film substrate) The film substrate 2 of the thermal transfer sheet may be any material as long as it has a certain degree of heat resistance and strength conventionally known, for example, 0.5 to 50 μm.
m, preferably a polyester film, a polystyrene film, a polypropylene film, a polysulfone film, an aramid film, a polycarbonate film, a polyvinyl alcohol film, a cellophane and the like having a thickness of about 3 to 10 μm, and a polyester film is particularly preferable.

(Heat-Resistant Layer) In the thermal transfer sheet of the present invention, a heat-resistant layer 6 can be provided on the other surface of the film substrate to prevent adverse effects such as sticking and print wrinkles due to heat of the thermal head. As the resin forming the heat-resistant layer, any conventionally known resin may be used, for example, polyvinyl butyral resin, polyvinyl acetoacetal resin, polyester resin, vinyl chloride / vinyl acetate copolymer resin, polyether resin, polybutadiene resin, Styrene / butadiene copolymer resin, acrylic polyol, polyurethane acrylate, polyester acrylate, polyether acrylate, epoxy acrylate, urethane or epoxy prepolymer, nitrocellulose resin, cellulose nitrate resin, cellulose acetopropionate resin, cellulose acetate butyrate Rate resin, cellulose acetate hydrodiene phthalate resin, cellulose acetate resin, aromatic polyamide resin, polyimide resin, polycarbonate resin, chlorine Polyolefin resins. Further, in order to further improve heat resistance, various isocyanate curing agents and monomers having an unsaturated bond, a reaction product with an oligomer may be used,
The curing method is not limited to curing means such as heating and irradiation with ionizing radiation.

[0013] As a slipperiness imparting agent to be added to or overcoated with a heat-resistant layer made of these resins, phosphate esters,
Silicone oils, graphite powders, silicone-based graft polymers, fluorine-based graft polymers, acrylic silicone graft polymers, acrylic siloxanes, silicone polymers such as aryl siloxanes, and the like, preferably polyols, for example, polyalcohol polymer compounds and polyalcohols This is a layer composed of an isocyanate compound and a phosphate compound, and it is more preferable to further add a filler. The heat-resistant layer, the resin described above, the slipperiness imparting agent, further filler, by a suitable solvent,
Dissolve or disperse to prepare an ink for forming a heat-resistant layer, and form it on the other surface of the film substrate by, for example, gravure printing, screen printing, or a reverse coating method using a gravure plate. It can be formed by applying and drying by means.

(Release Anchor Layer) The release anchor layer 3
Basically, it provides a base for metal deposition and protects the film substrate from heat during the deposition, and peels off between the film substrate and the release anchor layer by heating to form the outermost surface of the print. This is a layer for realizing metallic luster. After the transfer printing, the release anchor layer is transferred to the transfer receiving body together with the metal deposition layer, and is located above the metal deposition layer and is in close contact with the metal deposition layer to be a component of the recorded matter. Also, it is a layer that functions as a protective layer for improving the mechanical and chemical strength of the metal deposited layer such as abrasion and corrosion, and is a layer that is transparent enough to allow the metallic gloss of the metal deposited layer to be seen through.

Furthermore, the release anchor layer of the present invention has heat resistance so as to withstand high heat generated by a thermal head and not to form a matted metal deposited layer, which is not received by the conventional hot stamping method. Further, the release anchor layer of the present invention is a layer that does not require a curing treatment such as heat curing and can be easily provided by simply applying a solution and drying. In the present invention, as a material used for the release anchor layer having such heat resistance, a resin having an elastic modulus at 150 ° C. of 10 ⁶ Pa or more is used. In the case of printing using a general thermal head, the temperature that the release anchor layer receives is around 130 to 200 ° C.
With the above elastic modulus at 0 ° C., the release anchor layer is not deformed when the thermal head is heated, and can maintain a flat state.

The elastic modulus at 150 ° C. is 10 ⁶ P
Examples of the resin a or more include chlorinated polyolefin resin, polyarylate resin, norbornene-based hydrogenated resin, polyimide resin, polyamideimide resin, polyetheretherketone resin (PEEK), polyetherketone resin (PEK), and the like. Polyether ketones, polyether sulfone resins, polysulfone resins, polyphenylene oxide resins and the like. These are used alone,
Alternatively, they may be used as a mixture. In particular, among the above resins having heat resistance, in the present invention, by using at least one selected from chlorinated polyolefin resin, polyarylate resin, norbornene-based hydrogenated resin,
This is preferable because it has good releasability from the film substrate and can prevent deformation during heating of the thermal head.

The chlorinated polyolefin resin has a structure in which a chloro group is added to carbon of the polyolefin resin, and has a chlorination degree of 50% or more and a mass average molecular weight of 5,000.
It is preferably from 0 to 250,000, and if the degree of chlorination is less than 50%, the cut during printing becomes poor. Also,
If the weight average molecular weight is less than 5,000, deformation during heating of the thermal head is likely to occur, while if the weight average molecular weight is more than 250,000, cutting during printing becomes poor, which is not preferable.

The thickness of the release anchor layer is usually provided in the range of 0.1 to 10 g / m ^{2 in} terms of coating amount. Thickness 0.1
If it is less than g / m ^2, it will not function as a release anchor layer,
If it exceeds g / m ² , the foil breakage at the time of printing becomes worse, and it is not suitable for halftone tone recording. Further, the release anchor layer, for example, for the purpose of coloring the metal deposition layer with aluminum or the like, cyan, such as a known dye or pigment,
Colorants of magenta, yellow, black and other colors can be appropriately mixed.

(Metal Deposition Layer) The metal deposition layer 4 is formed by metallizing a metal such as aluminum, zinc, tin, chromium, gold, silver, or an alloy such as brass under vacuum such as vacuum deposition or sputtering. It is a metal thin film layer obtained. The thickness of the metal deposition layer is usually 100 to 1000 °,
Preferably, the range of 200 to 500 ° is sufficient to obtain metallic luster. If it is too thin, it does not reflect visible light to the extent that glossiness can be obtained, and if it is too thick, the foil breakage during printing deteriorates, making it unsuitable for halftone recording, and is uneconomical.

(Adhesive Layer) As the adhesive layer 5, wax or a thermoplastic resin alone or a mixture thereof is used. The adhesive layer mainly contains a wax having a melting point of 50 to 120 ° C. or a softening point and / or a thermoplastic resin. If the above melting point or softening point is too low,
When the thermal transfer sheet is wound and stored, blocking tends to occur. On the other hand, if the melting point or the softening point is too high, the adhesion to the transfer receiving body during thermal transfer is weakened, which is not preferable. As the above wax, specifically, carnauba wax, paraffin wax, microcrystalline wax, ester wax, Fuscher-Tropsch wax, various low molecular weight polyethylene, wood wax, beeswax, whale wax,
Various conventionally known waxes such as wax wax, wool wax, shellac wax, candelilla wax, petrolactam, partially modified wax, fatty acid ester and fatty acid amide can be used. Examples of the thermoplastic resin include ethylene-based copolymers such as ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, and ethylene-methacrylic acid copolymer, which are copolymers of ethylene and other polymerizable monomers. Polymer, polyethylene resin, polypropylene resin, polyvinyl acetate, polyester resin, polyurethane resin,
Styrene resin, acrylic resin, polyamide resin,
Polyvinyl alcohol, polyvinyl acetate, petroleum resin, phenolic resin, maleic resin, etc., or synthetic rubbers such as polyisoprene rubber, styrene-butadiene rubber, butadiene-acrylonitrile rubber, and elastomers such as natural rubber.

The softening temperature of the adhesive layer is defined as T2, and
Assuming that the softening temperature of the release anchor layer is T1, these relations are as follows.
T1> T2, and T1> 150 ° C., T1-T2>
It is preferred to have 30 ° C. Satisfy this relation
In this way, when the thermal head is heated, the adhesive layer
Release anchor layer when softened and melted
Reduces the flatness of the deposited layer without following the deformation of the adhesive layer.
It is possible to obtain a printed matter which can be held and has excellent glossiness.
The thickness of the adhesive layer depends on the surface shape of the material to be transferred.
But the glossiness of the metallized layer and the foil cutting properties are impaired.
Unless otherwise noted, forming thinner is better for print sensitivity and print quality.
This is preferred in terms of fixability and resolution of the obtained image. For example, paint
0.3-5.0 g / m in work volume^Two, Preferably 0.3 to
3.0 g / m^TwoGood range. 0.3g / m ^TwoLess than
Sufficient adhesive strength cannot be obtained. On the other hand, 5 g / m^Two
If it exceeds the limit, excessive energy is required to melt the adhesive layer.
This is necessary, and the foil breakage is undesirably reduced.

(Release Layer) In the thermal transfer sheet of the present invention, a release layer is not necessary since the release anchor layer has the function of a release layer, but the release property between the film substrate and the release anchor layer is insufficient. If it is, a release layer can be provided between the film substrate and the release anchor layer. As the release layer, for example, carnauba wax, paraffin wax,
Microcrystalline wax, ester wax, Fischer-Tropsch wax, various low molecular weight polyethylenes, wood wax, beeswax, whale wax, ibota wax, wool wax, shellac wax, candelilla wax, petrolactam, partially modified wax, fatty acid ester, fatty acid amide Various waxes can be used.

The release layer mainly contains the above-mentioned wax, and a resin other than the wax may be mixed and used if the releasability from the film substrate is appropriate. Such resins include, for example, rubber resins such as polyisoprene rubber, styrene butadiene rubber, butadiene acrylonitrile rubber, acrylate resins, polyvinyl ether resins, polyvinyl acetate resins, and vinyl chloride resins.
Vinyl acetate copolymer resin, polystyrene resin, polyester resin, polyamide resin, polyimide resin, polychlorinated olefin resin, polycarbonate,
Polyvinyl butyral-based resins and the like can be mentioned. The thickness of the release layer is 0.01 to 0.05 g / m ^{2 in} terms of a coating amount at the time of drying.
Is preferable. When it is less than 0.01 g / m ^2, not made a function as peeling layer, exceeds 0.05 g / m ^2, the release layer itself to matting, sufficient metallic luster can not be obtained.

The thermal transfer sheet of the present invention configured as described above is most suitable for a thermal printer using a thermal head, but can also be used as a transfer foil for a conventional hot stamping method. In addition, since it has excellent resolution, it is suitable for use in printing images such as characters and designs as an aggregate of minute patterns, and can impart metallic luster to these images. Therefore, as a density gradation expression method, an intermediate density can be reproduced by expressing the density gradation by the size of the transfer portion according to the size of the halftone dot, that is, by using the area gradation. In addition, as a method of the area gradation, a screen pattern or the like known in the printing field using a grain, a brick pattern, or the like can be used in addition to a halftone dot.

[0025]

The present invention will now be described in more detail with reference to the following examples.
explain. In the text, "parts" or "%" is not particularly noted.
Unless indicated, it is based on mass. (Example 1) Polyethylene terephthalate having a thickness of 6.0 μm
With a silicone film on one side.
Thickness of conductive polyester (the amount of coating when dried;
Like) 0.2g / m^TwoWas formed by coating. Then
The other surface has a thickness of 0.1 mm made of chlorinated polypropylene resin.
7g / m^TwoApply the following coating liquid to form the release anchor layer of
Done. Then, a further thickness of 300 on the release anchor layer
ア ル ミ ニ ウ ム Aluminum metal deposition layer formed by vacuum evaporation method
And a thickness of 1.5 g / m on the metal deposition layer. ^TwoBonding
The layer was formed by coating with the following coating liquid, and the heat of Example 1 of the present invention was
A transfer sheet was obtained.

Release anchor layer coating liquid Chlorinated polypropylene resin 20 parts (elastic modulus at 150 ° C. is 7 × 10 ⁸ Pa, chlorination degree 66%, mass average molecular weight 24000) toluene / methyl ethyl ketone (weight ratio 1/1) 80 Department

Adhesive layer coating liquid carnauba wax (melting point 85 ° C.) 15 parts Polyester resin (glass transition temperature 75 ° C.) 5 parts Water / isopropyl alcohol (mass ratio 1/1) 80 parts

Example 2 Example 2 was repeated except that the formation of the release anchor layer (0.7 g / m ² ) and the adhesive layer (1.5 g / m ² ) were changed to the following coating liquid. In the same manner as in Example 1, a thermal transfer sheet of Example 2 was produced. Release anchor layer coating liquid polyarylate resin 20 parts (elastic modulus at 150 ° C. is 2 × 10 ⁸ Pa) Toluene / methyl ethyl ketone (mass ratio 1/1) 80 parts

Coating solution for adhesive layer Vinyl chloride-vinyl acetate copolymer (glass transition temperature: 75 ° C.) 20 parts Toluene / methyl ethyl ketone (mass ratio 1/1) 80 parts

Comparative Example 1 The thermal transfer of Comparative Example 1 was carried out in the same manner as in Example 1, except that the formation of the release anchor layer (0.7 g / m ² ) was changed to the following coating solution. A sheet was prepared. Release anchor layer coating liquid acrylic resin 20 parts (elastic modulus at 150 ° C. is 5 × 10 ⁵ Pa) Toluene / methyl ethyl ketone (mass ratio 1/1) 80 parts

Comparative Example 2 The thermal transfer of Comparative Example 2 was carried out in the same manner as in Example 1 except that the formation of the release anchor layer (0.7 g / m ² ) was changed to the following coating solution. A sheet was prepared. Release anchor layer coating liquid chlorinated polypropylene resin 20 parts (elastic modulus at 150 ° C. is 8 × 10 ³ Pa, chlorination degree 30%, mass average molecular weight 240,000) toluene / methyl ethyl ketone (mass ratio 1/1) 80 parts

(Evaluation Method) Using the thermal transfer sheets of the above Examples and Comparative Examples, using cast-coated paper as an object to be transferred, and using a bar code printer ZEBRA140 manufactured by ZEBRA as a printer, and applying applied energy. Printing was performed at a printing speed of 2 inch / sec at a BurnTemp setting of +13, +15, and +17, and the following evaluation was performed.

(Specular glossiness of printed matter) With respect to each printed matter obtained under the above-mentioned conditions, the degree of specular gloss was visually inspected for mattness in a printed portion, particularly, a solid portion. The criteria for the evaluation are as follows. ：: The printed surface is not matted at all when solid printing is performed. Δ: Matting is observed on a part of the printing surface when solid printing is performed. ×: Most or all of the printing surface is matted when solid printing is performed.

(Resolution) The sharpness of the edge portion of the printed portion of each printed matter obtained under the above conditions was visually observed and examined. The criteria for the evaluation are as follows. ：: The sharpness of the edge portion of the printed portion is excellent. Δ: The sharpness of the edge portion of the printed portion is slightly inferior. ×: Poor sharpness at the edge of the printed area

The evaluation results are as shown in Table 1 below.

[Table 1]

[0036]

As described above, the thermal transfer sheet of the present invention is
At least one release anchor layer, a metal deposition layer, and an adhesive layer are sequentially provided on one surface of the film substrate, and the release anchor layer has an elastic modulus of 1 at a glass transition temperature of 150 ° C.
0 containing ⁶ Pa or more resins mainly, 50 is adhesive layer
Wax having a melting point of 120 ° C. or softening point and / or
Alternatively, by mainly containing a thermoplastic resin, the adhesive layer can be melted and transferred to the transfer target in a temperature range in which the release anchor layer is not deformed, so that the printing portion having excellent metallic gloss by thermal transfer using a thermal head or the like. Is obtained. That is, by setting the elastic modulus at 150 ° C. of the resin contained in the release anchor layer to be 10 ⁶ or more, even when the adhesive layer is at or above the transfer temperature and is softened and melted, the release anchor layer is The flatness of the vapor deposition layer can be maintained without following the deformation, and a printed matter having excellent gloss can be obtained.

[Brief description of the drawings]

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Thermal transfer sheet 2 Film base material 3 Peeling anchor layer 4 Metal deposition layer 5 Adhesive layer 6 Heat resistant layer

Claims (3)

[Claims] 1. A thermal transfer sheet in which at least a release anchor layer, a metal deposition layer and an adhesive layer are sequentially provided on one surface of a film substrate, the release anchor layer may have a thickness of 150 μm.
The adhesive layer mainly contains a resin having a melting point of 50 to 120 ° C. or a softening point and / or a thermoplastic resin mainly containing a resin whose elastic modulus at 10 ° C. is 10 ⁶ Pa or more. Thermal transfer sheet. 2. The thermal transfer sheet according to claim 1, wherein the resin of the release anchor layer is at least one selected from a chlorinated polyolefin resin, a polyarylate resin, and a norbornene-based hydrogenated resin. . 3. The chlorinated polyolefin resin has a chlorination degree of 50% or more and a weight average molecular weight of 5,000 to 25.
The thermal transfer sheet according to claim 2, wherein the thermal transfer sheet has a molecular weight of 000.