KR100265926B1 - Thermal transfer film - Google Patents

Abstract

The thermal transfer film of the present invention is a film in which a heat-sublimable dye layer region, a heat-melt ink layer region, and a transferable protective layer region are sequentially formed on one surface of one base film in a plane shape, wherein the dye layer The primer layer is formed only between the region and the base film, and the transferable protective layer region may include an adhesive layer formed as an upper layer of the peelable protective layer, and simultaneously print photographic images and letters or symbols. It is a thermal transfer film which is excellent in wear resistance and excellent in photographic image and character resolution. Such thermal transfer films are mainly used to make ID cards such as ID cards.

Description

Thermal transfer film

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer film, and more particularly, to a thermal transfer film capable of simultaneously printing a photographic image, a character or a sign, etc. will be.

The thermal transfer film is mainly used to produce a printed material having a relatively small number of prints, for example, an ID card such as an identification card, and conventional thermal transfer films include a thermally meltable thermal transfer film and a thermal sublimable thermal transfer film.

The heat-melt thermal transfer film is composed of a base film and an ink layer made of a heat-melt resin and a wax formed on the base film, and the ink layer is melted by a heat head or laser light and transferred to the transfer target. It is a film, and the heat-sublimable heat transfer film is composed of a base film and a dye layer formed of a sublimable dye and a binder formed on the base film, and the dye in the dye is sublimed by the heat means as described above and transferred to the transfer target. The film is anticorrosive.

The heat-melt thermal transfer film has excellent performance in printing monotone images such as letters or symbols, but is poor in expressing modified images such as face photographs. Sublimation thermal transfer films express modified images such as face photographs. Although the performance is excellent, the performance of printing monotone images such as letters or symbols is poor.

In addition, in the case of forming an image by using two transfer methods of sublimation transfer method and thermal melt transfer method, two ribbons are required, two print heads are required, and the size of the printer becomes large.

The technical problem to be achieved by the present invention is to provide a thermal transfer film having excellent performance for expressing a modified image such as a face photograph and forging a forged image such as a character or a sign, and excellent durability for a long time use.

1 is a cross-sectional view of a thermal transfer film according to an embodiment of the present invention.

2 is a plan view of a thermal transfer film according to an embodiment of the present invention.

3 is a schematic diagram of an ID card manufactured using the thermal transfer film according to the present invention .

* Drawing symbol *

1. Base film 2. Heat resistant slip layer

3. Primer layer 4. Sublimable dye layer area

4Y. Yellow layer 4M. Magenta Floor

4C. Cyan layer 5. Hot melt ink layer area

6. The transferable protective layer region 6a. Peelable Protective Layer

6b. Adhesive layer

In order to achieve the above technical problem, in the present invention, on one surface of one substrate film, the sublimable dye layer region, the heat-melt ink layer region, and the transfer protective layer region are all formed in a plane form thermal transfer In the film, a primer layer is formed only between the sublimable dye layer region and the base film, and the heat-melt ink layer region may further include a release layer under the ink layer. It provides a thermal transfer film, which may further include an adhesive layer as an upper layer of the peelable protective layer.

According to the present invention, a dye layer and an ink layer are simultaneously formed on one base film in a plane shape to simultaneously increase a forged image such as a character or a sign and a modified image such as a face photograph. In addition, the protective layer is also formed on the base film at the same time on the surface can increase the durability of the printed image.

A feature of the present invention is that in the thermal transfer film as described above, the primer layer is formed only in the lower layer of the dye layer region, and is not formed in the thermal meltable ink layer region or the lower layer of the transferable protective layer region. As a result, adhesion between the dye layer and the substrate can be maintained, thereby preventing the binder resin in the transfer layer from transferring together during sublimation transfer. The thermal sensitivity of the heat-melt transfer layer is sufficient, and the resolution of the character image is excellent. The cost of production is reduced.

The present invention is also characterized in that the binder used in the heat-melt ink layer contains 10 to 40 parts by weight of acrylic resin and 10 to 40 parts by weight of epoxy resin. It is possible to obtain a heat-melt ink layer that is excellent and has a high resolution.

Since the shape of the thermal transfer film of the present invention is not particularly limited, either the unit sheet form or the roll type in which the unit sheet is repeatedly formed can be used.

Hereinafter, a thermal transfer film according to an embodiment of the present invention will be described with reference to the drawings.

Referring to FIG. 1, the heat-sublimable dye layer 4 and the primer layer 3 of the three-color dye layers 4Y, 4M, and 4C are laminated on one surface of the substrate 1, and heat adjacent thereto. The meltable ink layer 5 and the transferable protective layer 6 are sequentially formed on the substrate 1 in plan view, and the heat resistant slip layer 2 is formed on the other surface of the substrate 1.

Substrate 1 is mainly a thermoplastic film such as polyethylene terephthalate, polyamide, polyvinylchloride, polyethylene, polypropylene, polyimide, polysulfone, and polycarbonate having a thickness of 0.5 to 50 μm, in particular polyethylene terephthalate film Preference is given to using. The preferable thickness of the base film is 3-20 micrometers.

A heat-resistant slip layer 2 is formed on the other side of the substrate 1, which is in contact with the thermal printer head to improve the heat resistance and carryability of the film and to improve the film. In the case of the roll type, the back side of the film is prevented from adhering to the dye layer surface.

The heat resistant slip layer 2 includes a thermosetting resin having a hydroxy group or a carboxyl group, a compound having two or more amino groups or a curing agent such as diisocyanate or triisocyanate, and an additive such as an optionally added phosphoric ester surfactant or talc The composition to use is used. Alternatively, a composition including UV curable resins and additives may be used.

The application amount of the heat resistant slip layer 2 may be any amount sufficient to satisfy the above functions, but is generally applied at about 0.1 to 1.0 g / m 2.

A primer layer or anchor layer 3 is formed on the other side of the base film 1, so that when the dye layer 4 is formed on the heat resistant substrate, adhesion between the dye layer and the substrate is maintained. Do it. This is because when the adhesion between the dye layer and the substrate is insufficient, the binder resin contained in the sublimable dye layer is also transferred when the sublimation transfer is performed on the surface of the image-receiving material. Therefore, the primer layer 3 is formed in the lower layer of the dye layer, and is not formed in the lower layer of the heat meltable ink layer 5 and the transferable protective layer 6.

As the primer layer 3, it is common to use water-soluble or solvent type resins, such as an acrylic resin or a polyester resin independently, and the coating amount is 0.1-1.0 g / m <2>.

The sublimable dye layer 4 is formed of an upper layer of the primer layer 3 and includes a sublimable dye and a binder. The dyes are selected based on thermal sensitivity, color tone, light resistance, and solubility in binders, including diarylmethane dyes, triarylmethane dyes, methine dyes, azomethine dyes, xanthine dyes, oxazine dyes, cyanomethylene Dyes, thiazine dyes, azine dyes, acridine dyes, benzeneazo dyes, azo dyes, spiropyran dyes, indolinospyropyran dyes, fluorane dyes, rhodamine lactam dyes, naphthoquinone dyes, anthraquinone dyes, etc. Can be used.

The dyes used for the sublimable dye layer 4 of the present invention are yellow, magenta, and cyan dyes, and the yellow dyes include Macrox Yellow 6G (Bayer Corporation) and MS. Yellow VP (Mitsuidoatsusa), Kayasett Yellow AG (Japan Kayakusa) and the like can be used as the magenta dye MS Magenta VP (Mitsuidoyatsusa), Kayased Red 130 (Japan Kayakusa), Waxolin Red YP-FW (ICC), MS-Red G (Mitsui Doatsu Chemical), etc. can be used, and the cyan dyes include Waxolin Blue AP-FW (Japan ICI), Kayasset Blue FR (Kayakusa, Japan), and Gaya. Set Blue 714 (Kayakusa, Japan) and MS Blue-100 (Mitsuido Atsusa) can be used.

The binder used for the dye layer 4 is generally used singly or in combination with various resins excellent in storage stability, heat resistance and heat transferability of the dye. Examples thereof include cellulose resins such as ethyl cellulose, vinyl resins such as polyvinyl butyral, polyvinyl acetal, polyvinyl chloride, and the like, of which polyvinyl butyral and polyvinyl acetal are preferably used.

The dye layer 4 dissolves or disperses the dye, the binder resin, and the release agent component in an appropriate amount of solvent, respectively, to form an ink for the dye layer, and then uses the gravure printing method, the screen printing method, the reverse roll coating method, or the like. It is applied onto a substrate and dried to form yellow (4a), magenta (4b), and cyan (4c) dye layers depending on the color of the dye. The coating amount is preferably 0.5 to 2.0 g / m 2, and the content of the dye contained in the dye layer 4 is preferably 20 to 60% by weight.

The heat meltable ink layer 5 is located adjacent to the primer layer 3 and the sublimable dye layer 4 and comprises a colorant, a resin, and a wax.

The colorant includes organic and inorganic pigments or dyes having excellent coloring density and heat resistance. Although dyes such as cyan, magenta and yellow may be used as colorants, carbon black is preferably used for character and symbol printing.

The wax is used as a carrier of dyes and pigments, and microcrystal waxes, carnauba waxes, polyethylene waxes, and the like are used.

The resin is used as a binder, and contains 10 to 40 parts by weight of the acrylic resin and 10 to 40 parts by weight of the epoxy resin in the total binder.

Generally, acrylic resins, polyester resins, epoxy resins, vinyl chloride-vinyl acetate copolymers, and polyvinyl butyral resins are used. In particular, acrylic resins have releasability and are excellent in wear resistance, and polyester resins are transfer materials. Since the suitability to (iii) is excellent and the epoxy resin is excellent in thermal sensitivity, when the acrylic resin, the epoxy resin, and the polyester resin are used in combination at an appropriate ratio, the thermal sensitivity is good. This excellent and high resolution heat-melt ink layer can be obtained.

The coating amount of the heat-melt ink layer 5 is determined in consideration of the density and thermal sensitivity of the ink, but is preferably 1.0 to 2.0 g / m 2.

The transferable protective layer 6 is located adjacent to the hot melt dye layer 5 and includes a peelable protective layer 6a and an adhesive layer 6b.

As the peelable protective layer 6, resin which is excellent in transparency, abrasion resistance, and chemical resistance, such as a melamine resin, an acrylic resin, a polyester resin, and a polyurethane resin, is used. In this case, inorganic particles such as silica, alumina, or calcium carbonate may be added within the range not to impair the transparency in order to improve the cutting property during printing, and also, such as polyethylene wax or silicone oil, to impart wear resistance or activity. Organic additives may be added. The particle size of the additive is 0.01 to 50 µm.

The coating amount of the peelable protective layer 6a is usually 1.0 to 3.0 g / m 2.

The adhesive layer 6b serves to effectively transfer the protective layer 6a. An acrylic resin, a vinyl chloride resin, a vinyl chloride-vinyl acetate copolymer, a polyester resin, or the like having good heat adhesiveness is used.

The thickness of the adhesive layer is usually 0.2 to 4 µm and the coating amount is usually 0.1 to 1.02 g / m 2.

Ultraviolet absorbers and ultraviolet absorbent ultrafine particles may be added to the adhesive layer 6b and / or the peelable protective layer 6a to impart a sunscreen effect.

Referring to FIG. 2, in the thermal transfer film of the present invention, the area of the heat-melt ink layer region 5 and the transferable protective layer region 6 is equal to the area of one dye layer of the dye layer region 4.

In the practice of the present invention, a gravure printing method is used as a method of coating to form each region of the thermal transfer film.

Examples of the transfer material for forming an image using the thermal transfer film of the present invention include thermoplastic films such as polyester, polyvinyl chloride, vinyl chloride-vinylacetate copolymer, or polycarbonate; Thermoplastic films designed with dye receiving layers; paper; Or woven or nonwoven fabrics made from synthetic paper such as polyester fibers, polyamide fibers, and polypropylene fibers. Thermoplastic films made of double vinyl chloride-vinylacetate copolymers are preferred because there is no need to make a dye receiving layer.

Such a transfer material card generally includes an emboss, a sinusoidal region, an IC memory, a magnetic layer and the like before transfer, but may also be formed after the transfer of the protective layer 6.

Referring to the process of the thermal transfer film of the present invention is printed on the transfer material as follows.

While the position of the transfer material is fixed, the thermal transfer film of the present invention is sequentially moved to the corresponding area of the transfer material and transferred. That is, when the thermal transfer film is placed above the transfer material such that the thermal sublimable dye layer faces the transfer material, a desired color tone image is formed based on the image information by heat means such as a heat head or a laser beam. Then, the heat-melt ink layer is placed on the transfer material, a desired letter or symbol is printed, and the transferable protective layer is transferred onto the printed image. When transferring the transferable protective layer, a hot stamper, a hot roll, a line heater, or the like may be used instead of the heat head.

The transferable protective layer may be transferred over the entire formed image, or may be transferred only to a part to act as a protective layer.

Hereinafter, the present invention will be described with reference to Examples. The application amount is based on the dry state unless otherwise specified.

It is a matter of course that the present invention is not limited only to the following examples.

<Example 1>

On one surface of the polyethylene terephthalate base film (1) having a thickness of about 5.7 µm, a width of 6.0 cm, and a length of about 50 cm, the composition of Table 1 was applied using a gravure method so that the coating amount was 0.5 g / m 2, and 120 ° C. After drying for 1 minute at to form a heat-resistant slip layer (2).

Heat resistant slip layer composition ingredient Composition ratio (parts by weight) Polyvinyl Butyral Resin (BX-1, Integral Chemistry) 6 Hardener (Coronate-L, NPU) 2 Organic Filler (Epostar S, Japan Catalyst) One Zinc Stearate One Methyl ethyl ketone 45 toluene 45

Next, another surface of the polyethylene terephthalate film 1 was coated with polyurethane at about 30 cm in length and about 6.0 cm in width so as to have a coating amount of 0.5 g / m 2, and dried to form a primer layer 3.

Next, on the primer layer 3, the yellow ink, magenta ink, and cyan ink of Table 2 prepared by dispersing each dye in toluene with a constant composition ratio were about 10 cm in length and about 6.0 in width using the gravure method. Each ink was applied sequentially to a plane so as to have a coating amount of 1.5 g / m 2, and dried to form a sublimable dye layer 4.

Sublimation Dye Layer Composition components Composition ratio (part by weight) Yellow ink Dye (Waxolin Yellow 3GP-FW) 3 Polyvinyl Butyral Resin (BX-1) 3 Polyethylene Wax (Polywax-500, Toyo Petroleum) 0.2 Methyl ethyl ketone 46.9 toluene 46.9 Magenta ink Dye (MS Magenta VP) 3 Polyvinyl Butyral Resin (BX-1) 3 Polyethylene Wax (Polywax-500, Toyo Petroleum) 0.2 Methyl ethyl ketone 46.9 toluene 46.9 Cyan ink Dye (Gayaset Blue 714) 3 Polyvinyl Butyral Resin (BX-1) 3 Polyethylene Wax (Polywax-500, Toyo Petroleum) 0.2 Methyl ethyl ketone 46.9 toluene 46.9

Next, the composition of Table 3 was applied on the polyethylene terephthalate base film (1) by about 10 cm in length, about 6.0 cm in width, and applied in a gravure method so as to apply an amount of 2 g / ㎡ and dried to the sublimable dye layer (4 ) Was formed next to the ink layer (5).

Thermal Melt Ink Floor Carbon Black (MA-100, Mitsubishi Carbon) 6 Acrylic Resin (BR-85, Mitsubishi Rayon) 4 Epoxy Resin (Epicote 3004, Kumho Shell) 6 Polyethylene Wax (Polywax-500, Toyo Petroleum) 4 Methyl ethyl ketone 40 toluene 40

Next, next to the dye layer 4, on the base film 1, the composition of Table 4 was applied and dried so that the length was about 10 cm, the width was about 6.0 cm, and the coating amount was 2.0 g / m 2. Then, the composition of Table 5 was applied thereon at an application amount of 1 g / m 2 and dried to form an adhesive layer.

Peeling protection layer Acrylic Resin (BR-85, Mitsubishi Rayon) 16 Polyester resin (byron-200, Dongyang spinning company) 4 Polyethylene Wax (Polywax-500, Toyo Petroleum) 2 Methyl ethyl ketone 39 toluene 39

Adhesive floor Vinyl chloride / vinyl acetate copolymer (VMCH, UCC) 10 Silicon Dioxide (TT-600, Aerosil) 0.2 Methyl ethyl ketone 44.9 toluene 44.9

<Example 2>

A thermal transfer film was prepared in the same manner as in Example 1, except that the heat-melt transfer layer 5 was prepared in the composition and composition ratio as shown in Table 6.

Composition Components Composition ratio (part by weight) Heat melting ink Carbon Black (MA-100, Mitsubishi Carbon) 6 Acrylic Resin (ER-85, Mitsubishi Rayon) 6 Epoxy Resin (Epicote 3004, Kumho Shell) 4 Polyethylene Wax (Polywax-500, Toyo Petroleum) 4 Methyl ethyl ketone 40 toluene 40

<Example 3>

Except for using the base film in the form of a roll, the same process as in Example 1 was repeated to prepare a roll-type thermal transfer film.

<Comparative Example 1>

A thermal transfer film was manufactured in the same manner as in Example 1, except that the primer layer was not formed below the dye layer in Example 1.

<Comparative Example 2>

A thermal transfer film was manufactured in the same manner as in Example 1, except that the primer layer was coated not only on the lower layer of the dye layer but also on the lower layer of the heat-melt transfer layer and the peelable protective layer.

<Comparative Example 3>

A thermal transfer film was manufactured in the same manner as in Example 1, except that the heat-melt ink layer was prepared in Example 1 as shown in Table 7.

Composition Components Composition ratio (part by weight) Heat melting ink Carbon black (BX-1, Mitsubishi carbon) 6 Polyvinyl Chloride-Polyvinyl Acetate Resin (YMCH, UCC) 6 Epoxy Resin (Epicote 3004, Kumho Shell) 4 Polyethylene Wax (Polywax-500, Toyo Petroleum) 4 Methyl ethyl ketone 40 toluene 40

<Printing test>

The thermal transfer film produced by the above-mentioned method was subjected to a printing test using a sublimation card printer manufactured by Datacard. Yellow, magenta, and cyan colors were sequentially transferred to obtain a color image, followed by printing a heat-fused transfer layer to obtain a character image, and then printing a transfer protective layer.

As can be seen from Table 8 below, in Examples 1 and 2, good photographic images and character images were obtained. On the other hand, in the case of Comparative Example 1, a good character image was obtained, but the resin of the dye layer was transferred to the plastic card to obtain a good photographic image. In the case of Comparative Example 2, a good photographic image could be obtained. The thermal sensitivity of the layer was insufficient and the resolution of the character image was insufficient. In the case of Comparative Example 3, the resolution of the character image was worse than that in Examples 1 and 2.

<Durability test>

The surface of the image obtained by printing the thermal transfer film prepared according to the above Examples and Comparative Examples was rubbed about 100 times with a load of 500 g / cm 2 with a rubbing tester (Toyose, Japan) and the degree of damage was visually observed. .

The results of the test are shown in Table 8 below.

Photo burn Letter and symbol burn Wear resistance Example 1 Good Good Good Example 2 Good Good Good Example 3 Good Good Good Comparative Example 1 Bad Good Bad Comparative Example 2 Good Bad Bad Comparative Example 3 Good Bad Good

In the thermal transfer film of the present invention, a heat-sublimable dye layer and a heat-melt ink layer are sequentially formed on one substrate film in a plane shape, so that both the reconstructed image such as a face photograph and the resolution of a forged image such as a character or a sign are both It is excellent in that the protective layer is formed on the surface of the base film at the same time excellent in durability. In particular, since the primer layer is formed in the lower layer of the dye layer region, the binder is prevented from being sublimated together by maintaining the adhesive force, and the resolution of the text image is excellent and the production cost is reduced.

Claims (5)

In a thermal transfer film in which a thermal sublimable dye layer region, a heat meltable ink layer region, and a transfer protective layer region are sequentially formed on one surface of one substrate film in plane, only between the dye layer region and the substrate film. Thermal transfer film, characterized in that the primer layer is formed. 2. The thermal transfer film according to claim 1, wherein the heat-melt ink layer region includes a release layer formed under the ink layer. 2. The thermal transfer film according to claim 1, wherein the transferable protective layer region is composed of a protective layer and an adhesive layer, and an adhesive layer is formed on the upper layer of the protective layer. 2. The thermal transfer film according to claim 1, wherein the thermally meltable ink layer contains 10 to 40 parts by weight of an acrylic resin as a binder and 10 to 40 parts by weight of an epoxy resin as a binder. The method of claim 1, wherein the thermal transfer film is a heat transfer film, characterized in that the shape of the unit sheet form or the unit sheet is repeatedly formed in a roll form.