JP4822529B2 - Thermal transfer recording method - Google Patents

Description

The present invention is a thermal transfer recording apparatus such as a thermal transfer printer or a facsimile having indicia image head such as a thermal head, using a thermal transfer recording medium, the impression particularly exhibiting metallic luster (characters, images, etc.) the material to be transferred onto The present invention relates to a thermal transfer recording method .

Conventionally, a thermal transfer recording medium for forming a print image exhibiting a metallic luster is known. For example, Patent Document 1 describes a metal gloss thermal transfer recording medium having a structure in which a release layer, a vapor deposition anchor layer, a metal vapor deposition layer, and an adhesive layer are laminated in this order on a substrate. In the case of thermal transfer to a packaging material or the like, if the packaging material is a nonpolar material such as PP, the adhesive layer of the metallic gloss thermal transfer recording medium uses a material having a strong adhesive force to the packaging material. When the adhesive force of the adhesive layer is increased, the print image is not cut easily, and a problem of surface peeling that causes thermal transfer to an area that is not originally thermally transferred has occurred. In this case, if many particles such as extender pigments and colored pigments are added to the vapor deposition anchor layer in order to improve the cut of the printed image, there is a problem that the cut of the printed image is improved but the gloss is lowered.
JP 63-30288 A

The present invention provides a thermal transfer recording method using a metallic gloss thermal transfer recording medium to maintain a high gloss of metallic gloss and improve the cutout of a printed image.

The present invention that solves the above-mentioned problems is selected from a transfer control layer comprising at least a polyamide resin, a release layer, an anchor layer, a metal vapor deposition layer, a chlorinated polypropylene resin, and a maleic anhydride-modified polypropylene resin on a substrate. A thermal transfer recording method characterized in that a metallic gloss thermal transfer recording medium in which an adhesive layer composed of at least one kind of adhesive resin is laminated is thermally transferred onto an olefin resin film to form a printed image having metallic gloss .

A printed image that has been thermally transferred to a transfer medium using the above-described metallic glossy thermal transfer recording medium can obtain a printed image with high gloss that has good cut-off of the printed image and no problem of surface peeling. In particular, the printed image can be obtained on an object to be transferred which is coated with an olefin film or an olefin resin.

In the present invention, by providing a transfer control layer between the base material and the release layer, a high-gloss image can be obtained without planar peeling. The reason why the surface peeling does not occur at the time of transfer is considered that only the heated portion is transferred due to the presence of the transfer control layer. The transfer control layer is formed of a thermoplastic resin. Examples of the thermoplastic resin include polyamide resin, polyester resin, urethane resin, and polyvinyl acetate resin.

  Among these thermoplastic resins, adhesiveness to a release layer using a polyamide resin and transferability are good, and planar peeling can be strongly suppressed, which is particularly preferable. Furthermore, the softening point of the polyamide resin is preferably not in the range of 70 to 120 ° C. A particularly preferred range is from 85 to 105 ° C. If it is less than the above range, the transferability is lowered. When the above range is exceeded, the sharpness deteriorates.

  In order to adjust the thermal transferability, the transfer control layer may contain waxes mentioned in the later-described release layer. Further, the transfer control layer may contain particles in order to adjust the adhesion with the release layer. The particles include organic particles such as silicone particles, melamine particles, and benzoguanamine particles, and inorganic particles such as silica, talc, calcium carbonate, precipitated barium sulfate, alumina, clay, magnesium carbonate, carbon black, tin oxide, and titanium oxide. Can be mentioned. The size of the particle is larger than the thickness of the transfer control layer, and a part of the particle needs to bite into the release layer. However, if the particles penetrate the release layer and bite into the deposition anchor layer, the layer surface of the deposition anchor layer becomes uneven, and the metal deposition layer provided thereon becomes uneven and the gloss decreases. Needs to have a size that does not penetrate into the deposition anchor layer.

  The coating thickness of the transfer control layer is suitably about 0.1 to 2.0 μm. The effect of invention cannot be acquired as it is less than the said range. If it exceeds the above range, the transfer sensitivity is lowered.

As the substrate, any film or sheet generally used as a substrate for thermal transfer recording media can be used, and examples thereof include plastic films such as polyester films, polyamide films, and polycarbonate films. The substrate thickness is 1-10
About μm is appropriate. If necessary, it is preferable to provide a heat-resistant protective layer on the back surface of the substrate in order to prevent sticking to the thermal head.

  The release layer is melted by a thermal signal from a thermal head or the like at the time of thermal transfer, and has a function of facilitating the peeling of the transfer layer (consisting of a vapor deposition anchor layer, a metal vapor deposition layer, and an adhesive layer) from the substrate. . The release layer is mainly composed of waxes, and if necessary, a thermoplastic resin (including an elastomer) may be blended in order to adjust the adhesion to the substrate or the vapor deposition anchor layer.

Examples of the waxes include natural waxes such as carnauba wax, candelilla wax and montan wax; petroleum waxes such as paraffin wax and microcrystalline wax; One kind or two or more kinds of synthetic waxes such as polymer wax can be used.

  Examples of the thermoplastic resin include polyester resins, polyamide resins, polyurethane resins, ethylene-vinyl acetate copolymers, vinyl chloride-vinyl acetate copolymers, polyvinyl butyral, α-olefin-maleic anhydride systems. One or more of copolymers, acrylic resins, styrene resins, petroleum resins, rosin resins, terpene resins, polypropylene resins and ionomer resins can be used.

The release layer can be formed by applying and drying the waxes and, if necessary, the resin dissolved or dispersed in an appropriate solvent (including water) on a substrate. It can also be formed by hot melt coating. The coating amount of the release layer is suitably about 0.1 to 1 g / ^{m 2.}

The vapor deposition anchor layer functions as a metal deposition surface during vapor deposition when forming the metal vapor deposition layer, and also functions as a support layer for the formed metal vapor deposition layer, and has a resin component as a main component. . When a metallic luster having various hues not limited to the metallic luster color unique to the metal vapor deposition layer is desired, a colorant may be added to the vapor deposition anchor layer. Examples of the colorant include dyes and pigments. However, it is preferable to use a dye when a high-gloss image is required to make the vapor deposition anchor layer opaque. By including the colorant, the vapor deposition anchor layer is placed on the metal vapor deposition layer of the heat-transferred transfer layer, and a color metallic gloss image can be obtained. That is, the deposition anchor layer has a function of a colored layer. (Hereinafter, the metallic gloss thermal transfer recording medium in which a coloring agent is blended in the vapor deposition anchor layer is referred to as a color metallic gloss thermal transfer recording medium.)
When a pigment is used as a colorant, it works as a transfer layer cutting agent because the pigment takes a particulate form, but when a dye is used, the dye is dissolved in a vapor deposition anchor layer in a molecular state, like a pigment. Does not work as a cutting agent. For this reason, the printed image of the color metallic gloss thermal transfer recording medium using the dye is likely to cause surface peeling. Even if it is a color metal gloss thermal transfer recording medium using a dye, a color glossy thermal transfer recording medium having a transfer layer having the structure of the present invention can obtain a high-gloss color image without surface peeling. I can do it.

  As an image removal agent, particles such as extender pigments may be blended in the vapor deposition anchor layer, but this is also preferable because it makes the vapor deposition anchor layer opaque.

  As a resin component of a vapor deposition anchor layer, the thing of the range whose glass transition point is 50-120 degreeC is preferable. If the glass transition point of the resin component is less than 50 ° C., the heat resistance as a deposition surface during the vapor deposition process is poor, and a high gloss metal deposition layer tends to be not obtained, whereas if the glass transition point exceeds 120 ° C. Although a high-gloss metal deposited layer is obtained, the transferability tends to be inferior.

  Examples of the resin component include acrylic resins, polyester resins, polyamide resins, cellulose resins such as nitrocellulose, polyurethane resins, and epoxy resins. These may be used alone or in combination of two or more. An acrylic resin is particularly preferable.

  The vapor deposition anchor layer can be formed by applying and drying a coating solution prepared by mixing particles, if necessary, a colorant, etc., into the solvent solution or dispersion liquid (including emulsion) of the resin component, and drying it. .

  The thickness of the vapor deposition anchor layer is not particularly limited as long as it exhibits its original function, but generally it is preferably in the range of 0.2 to 1 μm. When the thickness is smaller than the above range, the original function is hardly exerted. On the other hand, when the thickness is larger than the above range, the transferability tends to be impaired.

  As the metal of the metal vapor deposition layer, simple substances such as amylnium, zinc, tin, nickel, chromium, titanium, copper, silver, gold, and platinum, a mixture, an alloy, and the like can be used, but usually aluminum is preferably used. The metal vapor deposition layer can be formed by a physical vapor deposition method such as a vacuum vapor deposition method, a sputtering method, an ion plating method or a chemical vapor deposition method.

  The thickness of the metal vapor-deposited layer is preferably 10 to 100 nm, and more preferably 20 to 80 nm from the viewpoint of obtaining a high gloss metal luster.

  The adhesive layer is mainly composed of an adhesive resin. Examples of the adhesive resin for the adhesive layer include polyester resin, polyamide resin, polyurethane resin, ethylene-vinyl acetate copolymer, ethylene- (meth) acrylate ester copolymer, petroleum resin, and rosin. 1 type, or 2 or more types, such as a series resin, a terpene series resin, a chlorinated polypropylene resin, and a maleic anhydride-modified polypropylene resin.

The adhesive layer can be formed by dissolving or dispersing the adhesive resin in an appropriate solvent (including water), and applying and drying a dispersion of particles on the metal vapor deposition layer as necessary. The coating amount of the adhesive layer is suitably about 0.2~1g / ^{m 2.}

The material to be transferred, to use an olefin-based resin film of polypropylene or polyethylene. When heat-transferring to such a resin film , it is necessary to select a resin having a strong adhesive force with respect to the olefin film as the adhesive layer. For example, chlorinated polypropylene resin, maleic anhydride-modified polypropylene resin and the like can be mentioned.

When a resin having a strong adhesive force is used for the adhesive layer, the surface peeling of the print image is likely to occur. Even in such a case, if the above-described metal gloss thermal transfer recording medium is used, a high gloss image can be obtained without surface peeling of the image.

A coating solution for a transfer control layer having the composition shown in Table 1 was applied to the other surface of a 4.5 μm thick polyethylene terephthalate film having a silicone resin heat-resistant protective layer formed on one surface, and dried. A transfer control layer of ³ g / m ² was formed.

For the examples and reference examples in Table 1, Comparative Example 1 was used without a transfer control layer.
Table 1 Coating liquid for transfer control layer

Example 1-2, Reference Examples 3-4 and of creating the transfer control layer to applying a release layer coating solution having the following composition Comparative Example 1, the release layer of the coating amount of 0.5 g / m ² and dried Formed.

Release layer coating liquid Ingredient Weight part Carnauba wax 10.0
Toluene 90.0

  On the release layer, an anchor layer coating solution having the following composition was applied and dried to form an anchor layer having a thickness of 0.5 μm. The anchor layer coating solution was prepared by stirring for 1 hour with a desper. An aluminum vapor deposition layer having a thickness of 20 nm was formed on the anchor layer by vacuum vapor deposition.

Coating liquid for anchor layer Component Weight part Acrylic resin (Tg 105 ° C.) 8.0
Yellow dye 2.0
Toluene 40.0
MEK 50.0

An adhesive layer coating solution having the following composition was applied onto the aluminum vapor-deposited layer and dried to form an adhesive layer having a coating amount of 0.3 g / m ² .
Adhesive layer Component Weight parts Chlorinated polypropylene resin 8.0
(Tg80 ℃)
Silica particles 2.0
Toluene 90.0

Evaluation Method Using the following printer, the barcode pattern was thermally transferred to the transfer target. Evaluation was performed according to the evaluation criteria. The evaluation results were as shown in Table 2.
Thermal transfer printer used: SD-2 (manufactured by Markem)
Transfer object: Evaluation standard for OPP film with a thickness of 50 μm (1) Image transferability ◎ High sensitivity printing possible without transfer control layer ○ Slight sensitivity decrease compared to without transfer control layer △ Compared with no transfer control layer Decrease in sensitivity is observed (2) Planar peeling ○ No stripping on the printed image x Planar peeling is seen on the printed image

Table 2 Evaluation results

Claims (1)

Adhesion comprising at least one adhesive resin selected from a transfer control layer comprising at least a polyamide resin, a release layer, an anchor layer, a metal vapor deposition layer, and a chlorinated polypropylene resin and a maleic anhydride-modified polypropylene resin on a substrate. A thermal transfer recording method comprising: forming a printed image having a metallic luster by thermally transferring a metallic gloss thermal transfer recording medium having laminated layers onto an olefin resin film.