JPS6176397A - Heating transfer sheet - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat transfer sheet that transfers only necessary portions. The present invention also includes a heated transfer sheet having a partially vapor-deposited portion of metal, which transfers only the necessary portion.

In heat transfer painting, a layer of release agent is provided on a layer slightly thicker than the pattern ink area of the base material or over the entire surface of the film, the desired pattern is printed on top of it with colored ink, and then a heat-sensitive type is applied. A commonly used method is to apply a transfer sheet provided with an adhesive layer to an object to be transferred, and transfer the image by applying heat and pressure.

After transfer, the above-mentioned layer of release agent forms a protective coating for the colored ink layer, but due to the above-mentioned structure of the transfer material, the former method also allows the surrounding area where the image is not printed to be removed by a certain width. Since a layer of release agent is applied to the surface of the transfer material, the appearance, such as gloss, is different from that of the surface of the transferred object, so there is a problem that the border is noticeable and feels unnatural. Also, if you use the latter method to uniformly cover a certain area of surface including the pattern with a layer of release agent, the unnaturalness around the pattern will disappear, but the border will still be noticeable at the edges, and the excess peeling will If a layer of agent remains, a condition known as "poor foil cutting" occurs.
After all, the value of the transfer product will be lower.

The present invention has been made in order to solve the above-mentioned difficulties and realize painting with excellent aesthetic effects, and provides a heat transfer sheet that can transfer only the parts necessary for painting. The purpose is to

The heating transfer sheet of the present invention, which transfers only the necessary parts,
As shown in FIG. 1A, which is a schematic cross-sectional view, a layer 12 of a release agent is coated on the entire surface of a heat-resistant film base 11.
In addition, a colored ink layer 13 is applied to the part representing an arbitrary pattern.
and a layer 16 of heat-sensitive adhesive are stacked in this order.

As shown in FIG. 1B, which is also a schematic cross-sectional view, between the colored ink layer 13 and the heat-sensitive adhesive layer 16,
It may also have a layer 15 of a metal vapor deposited film.

The heat transfer sheets 1A and 1B of the present invention having the above-mentioned configuration can be used for painting according to a conventional heat transfer method. That is, the surface of the heat-sensitive adhesive layer 16 is applied to the surface of the transfer target 20, heat is applied under pressure through the film base material 11, and the film base material 11 is peeled off after adhesion, as shown in FIG. Thus, a transferred picture 2 is obtained with the release agent layer 12 on the surface. Since there is no heat-sensitive adhesive layer 16 underneath the unprinted area, the release agent layer 12 in that area does not adhere to the surface of the transfer target 20 even when heated and pressed, and the film base material 11 The adhered portion is cut off by tearing and removed together with the base material 11. In this way, transfer is performed only to the necessary portions.

In order to obtain the above heat transfer sheet using ordinary printing techniques, it is sufficient to apply a colored ink layer and then print a heat-sensitive adhesive in synchronization with the colored ink layer. However, for beautiful painting, it is desirable that the heat-sensitive adhesive be colorless and transparent. Registration of printing with clear, colorless ink is practically impossible with current technology. Furthermore, even if a colored heat-sensitive adhesive can be used, it would be clearly advantageous in terms of the process if the need for registration could be eliminated and the entire surface coated instead.

The method for producing a heat transfer sheet that coats the entire surface with a heat-sensitive adhesive and has it only in the necessary areas is to provide a layer of release agent on the entire surface of a heat-resistant film base material, and then apply a layer of release agent on the entire surface of the film base material. A layer of resin that is virtually insoluble in water but swells in water is partially provided to represent the pattern, a layer of colored ink is applied to the layer, and a layer of heat-sensitive adhesive is applied on top of this layer. The resin is applied over the entire surface, then water is applied to swell the resin, and the swollen resin is removed together with the layer of heat-sensitive adhesive adhered thereon.

This process will be explained in order with reference to the drawings. First, as shown in FIG. A layer 14A of water-swellable resin is provided on a portion not intended for transfer, and then a layer 13 of colored ink is applied in synchronization with this. It is also possible to apply the water-swellable resin and the colored ink in the reverse order. Then, a layer 16 of heat-sensitive adhesive is applied to the entire surface.

Next, when water is applied to the entire surface by immersing it in water or spraying it with water, the water-swellable resin layer 14A absorbs the water and becomes as shown as 14B in FIG. The volume increases significantly.

Along with this, the heat-sensitive adhesive layer 1 attached thereon
6 is sharply cut along the contour of the water-swellable resin 14A.

When the swollen resin 14B is removed, a colored ink layer 13 and a heat-sensitive adhesive layer 16 remain in desired areas, as shown in FIG. 1A. Mechanical means such as wiping with a cloth or scraping with a fine brush are effective for removal. Since the resin 14B in the swollen state becomes a jelly-like gel and the adhesion between it and the release agent layer 12 is weakened, it can be almost completely removed.

In order to manufacture a thermal transfer sheet having a metal vapor deposited film layer 15 between a colored ink layer 13 and a heat-sensitive adhesive layer 16 as shown in FIG. After providing the colored ink layer 13, the heat-sensitive adhesive layer 1
6, metal may be vapor-deposited on the entire surface. When the resin swells by application of water, the metal vapor deposited film is cut together with the heat-sensitive resin layer as the volume increases, and unnecessary portions are removed together with the swollen resin.

The film base material used in the production of the heat transfer sheet in the present invention not only requires heat resistance, but also water resistance. Specifically, cellophane, polyester film, silicone release paper, processing paper for synthetic leather, etc. are suitable. It also has a moderate releasability between the release agent layer and the part that is adhered to the object to be transferred with the adhesive, which is easily peeled off, but the part that is not adhered is not peeled off and is taken away. Since the release properties differ depending on the release agent used, they should be selected as a combination. The thickness is also selected based on the relationship between the required strength and material. Usually, it is in the range of 10 to several tens of microns.

As mentioned above, the release agent must be applied to the entire surface of the film substrate and must have the property of being released from it, and must also serve as a transparent protective film for the ink after transfer. A typical material is an acrylic ester-based synthetic resin, which is dissolved in an appropriate solvent and applied by gravure coating, roll coating, silk screen coating, or the like. The coating amount is usually 1 to 10 g/TIt.
If necessary, two or more layers of the same or different types can be stacked.

The water-swellable resin that is applied to the area from which the heat-sensitive adhesive (and metal vapor deposition) is to be removed is soluble in an organic solvent and printed using the gravure printing method. do. The aforementioned jelly-like appearance makes it easier to remove mechanically, the heat-sensitive adhesive (and metal vapor deposition is included when applied) is sharply sheared due to volumetric expansion, and a small amount remains. Even if there is a problem, the water resistance of the image after transfer will not be damaged.
In order to reliably meet these demands, it is important to appropriately select the degree of swelling of the resin with water. Usually, the preferred degree of swelling is in the range of 7-25.

The colored ink layer is a layer of transparent or opaque water-resistant ink containing dyes or pigments, which is in harmony with the metallic luster imparted by the metallized film, if present. Select and print in an appropriate manner. This printing can also be carried out according to conventional techniques.

When a metal vapor deposition film is provided, a metal such as aluminum or copper is vacuum-deposited to a thickness of several hundreds of layers. The method is known to those skilled in the art.

Finally, the heat-sensitive adhesive to be applied to the entire surface is selected mainly depending on the type of object to be transferred. When the material of the typical plastic molded article to be transferred is polypropylene, polystyrene, or ABS resin, chlorinated polyethylene, acrylic, or rubber is used. For application, gravure coating, roll coating, etc. are convenient. The thickness of this layer may be limited to the extent that it provides the necessary adhesion.

The heat transfer sheet of the present invention, which transfers only the necessary areas, does not transfer the release agent layer to areas that are not transferred according to the pattern, so it is possible to paint with a natural beauty without changing the appearance of the transferred object. .

Example 1 A polyethylene terephthalate film having a thickness of 25 μm was used as a base material, and a solvent solution of maleic acid resin in toluene/methyl ethyl ketone = 1/1 was applied as a release agent to the entire surface by gravure coating.

Aquaprene L-71, an acrylic water-swellable resin
0 (manufactured by Kaisei Kagaku Kogyo Co., Ltd., water swelling degree 20-25) was dissolved in a solvent and applied on the release agent layer by gravure printing in a manner consistent with the desired pattern. Furthermore, a pattern was printed on it using gravure ink prepared from acrylic resin, pigment, and dye.

Finally, the entire surface was gravure coated with a toluene solution of chlorinated polypropylene as a heat-sensitive adhesive.

This was immersed in water at room temperature for about 5 minutes, and then the swollen portion was wiped off with a cloth and dried.

The transfer sheet thus obtained was thermally pressed and transferred onto the surface of a polypropylene molded product using a silicone rubber roll at a temperature of 200'C.

The transferred painting obtained by peeling off the polyester film had an improved aesthetic appearance as only the necessary design was transferred.

Example 2 A heat transfer sheet was prepared in the same manner as in Example 1, except that aluminum was vacuum-deposited prior to applying the heat-sensitive adhesive, and this was also transferred to the surface of a polypropylene molded product under the same conditions. . This product had an improved aesthetic appearance, with only the necessary designs being transferred and the metal vapor deposited areas being clearly visible.

[Brief explanation of drawings]

FIG. 1A is a cross-sectional view schematically showing a basic embodiment of a heating transfer sheet for transferring only the necessary portions of the present invention, and FIG. FIG. FIG. 2 is a similar cross-sectional view showing the thermal transfer sheet of FIG. 1A applied to a transfer object (with the top and bottom reversed), the film base material being peeled off, and the decorated product being made into a product. 3 and 4 are schematic cross-sectional views showing the steps of the method for producing the heat transfer sheet of the present invention. Figure 4 shows a stage in which a layer of water-swellable resin and a layer of colored ink are provided, and a layer of heat-sensitive adhesive is provided on the entire surface. The stages at which the layer of agent was sheared are shown in each case. 1A, 1B... Heat transfer sheet 2... Transferred picture 11... Film base material 1
2... Release agent layer 13... Colored ink layer 14
A... Water-swellable resin layer 14B... Water-swellable resin (swollen state) 15... Metal vapor deposited film layer 16... Heat-sensitive adhesive layer 20... Transferred material

Claims (2)

[Claims] (1) Transfer only the necessary parts onto a heat-resistant film base material, with a layer of release agent on the entire surface, and a layer of colored ink and a layer of heat-sensitive adhesive on the part representing the desired pattern. Heat transfer sheet. (2) A thermal transfer sheet that transfers only the necessary portions according to claim 1, which has a metal vapor deposited film layer between the colored ink layer and the heat-sensitive adhesive layer.