JPS5823233B2 - transfer foil - Google Patents

Description

[Detailed description of the invention] The present invention relates to a novel transfer foil.

More specifically, the present invention relates to a transfer foil for hot stamping that has excellent corrosion resistance, weather resistance, and crack resistance.

Typical examples of conventional transfer foils for hot stamping include those provided with a thin metal layer made of aluminum or those provided with a thin metal layer made of chromium.

However, with transfer foils provided with a thin metal layer made of aluminum, the thin metal layer is susceptible to corrosion by salt water or alkaline liquid, and there are problems in terms of corrosion resistance, and there are also problems in terms of weather resistance. When such transfer foils are hot-stamped to produce outdoor decorations or automobile exteriors, they have the disadvantage that they lose their metallic luster within a short period of time.

On the other hand, a transfer foil provided with a thin metal layer made of chromium has excellent corrosion resistance and weather resistance, but has a major drawback of poor impact resistance during transfer and poor crack resistance during cooling and heating cycles.

As a result of various studies on the causes of cracks in transfer foils provided with a thin chromium layer, the present inventors found that the thin chromium layer has a very large internal stress during formation and that the plastic i-based material to be transferred is It has been assumed that the main cause of cracks is the large difference in thermal expansion coefficient between the material and the material.

Therefore, as a result of further research in order to find an additive element that could provide excellent crack resistance to a thin chromium layer by eliminating these causes of crack occurrence, we found that Va.
The present invention was completed based on the knowledge that the group elements are optimal as additive elements because they have excellent internal stress relaxation properties when forming a thin chromium layer and have a small coefficient of expansion. It happened.

That is, the present invention provides a thin metal layer of a transfer foil that is homogeneous enough to be composed of chromium A and at least one element B of the Va group. Concerning extremely excellent transfer foil.

F. Examples of the Va group element B include bismuth, antimony, arsenic, phosphorus, etc. Among these, arsenic is a poisonous substance to the human body, so it is preferable to avoid its use as much as possible.

Therefore, preferred embodiments of the metal thin layer characterized by the present invention are (1) chromium bismuth, (2) chromium bismuth antimony, (3) chromium bismuth phosphorus,
(4) Chromium, bismuth, antimony, phosphorus, (5) chromium, antimony, (6) chromium, antimony, phosphorus,
(7) Each combination of chromium and phosphorous can produce a thin metal layer.

Therefore, these metal thin layers exist in a state in which element B of the Va group, which has an excellent expansion coefficient and has excellent internal stress relaxation properties, is almost uniformly dispersed in chromium N, which is the main component.

Because they are homogeneous thin layers, they all have excellent crack resistance, and the main component, chromium A, ensures excellent corrosion resistance and weather resistance.

In such a thin metal layer, the weight ratio of chromium N as a main component and Va group element B as an additive component is 100:0.1.
The ratio is preferably within the range of 100:10.

That is, at such a specific ratio, the main component, chromium A, can significantly improve crack resistance without impairing the originally excellent corrosion resistance and weather resistance.

On the other hand, when the ratio of chromium A and Va group element B is below the specified range, the improvement in crack resistance is not significant, while when it exceeds the specified range, corrosion resistance and weather resistance are reduced. Because of this tendency, neither of them can sufficiently achieve the purpose of the present invention.

The thickness of the metal thin layer is preferably within the range of 200 to 1000 people.

If the number is less than 200, it will be difficult to change the metallic luster inherent to Chromium A, and if the transfer foil is hot-stamped, there will be problems such as a lack of hiding power on the plastic substrate. This is because it causes inconveniences such as not being able to significantly improve crack resistance.

Such a thin metal layer can be easily formed by a conventional metal thin film forming method such as a vacuum evaporation method, a sputtering method, or an ion blasting method.

The formation conditions are obvious to those skilled in the art and will not be described in detail, but for example, when using a vacuum evaporation method, the degree of vacuum is 3X.
10'~1x10-6 Torr, evaporation source temperature 300~20
The temperature may be appropriately selected from the range of 00 DEG C., and when the sputtering method is used, the temperature may be appropriately selected from the vacuum degree of 5.times.10@-2 to 1.times.10@-3 Torr in an inert gas atmosphere such as argon.

The transfer foil of the present invention is characterized in that a specific metal thin layer as described above is provided as the metal thin layer,
There are no restrictions on the laminated structure of the transfer foil or its material.

Therefore, the transfer foil of the present invention includes any embodiment of the transfer foil as long as it is provided with the specific metal thin layer as described above.

Hereinafter, typical embodiments thereof will be described with reference to the drawings.

1 to 4 are schematic enlarged partial longitudinal sectional views showing typical embodiments of the transfer foil according to the present invention, respectively.

Here, 1 is a base film, 2 is a transparent or translucent resin layer, 3 is a thin metal layer, 4 is a 1g adhesive layer, 5 is a release layer,
6 is a metal film protective layer, and 7 is a static electricity removal layer.

That is, the transfer foil shown in FIG. 1 is made by sequentially laminating a transparent or translucent resin layer 2, a thin metal layer 3, and a heat-sensitive adhesive layer 4 on one side of a base film 1, and makes it heat-sensitive by hot stamping. The adhesive layer 4 is welded to the plastic base material, whereby the layers 2, 3 and 4 are peeled off from the base film 1 as one body and transferred.

The transfer foil of this embodiment is suitably employed when the peelability between the base film 1 and the transparent or semitransparent resin layer 2 is good.

The transfer foil shown in FIG. 2 has a release layer 5 laminated between the base film 1 and the transparent or translucent resin layer 2 in order to improve their releasability.

The transfer foil shown in FIG. 3 has the above-mentioned release layer 5 laminated to improve releasability, and a metal film protective layer 6 is laminated between the metal thin layer 3 and the heat-sensitive adhesive layer 4 to make it heat-sensitive. This prevents the thin metal layer 3 from being adversely affected (for example, partial damage to the thin metal layer) when the adhesive layer 4 is welded.

In addition, the transfer foil of this embodiment has the advantage of being able to select a wide range of adhesives and the advantage of preventing corrosion of the thin metal layer.

The transfer foil in FIG. 4 includes the release layer 5 and the metal film protective layer 6.
In addition to laminating the base film 1, a static electricity removal layer 7 is further laminated on one side opposite to the base film 1 to prevent coating unevenness caused by the adhesion of floating substances such as dust and dirt when laminating each layer of 5.2 and 6. It is.

For these transfer foils, there are no particular restrictions on the material and thickness of the base film 1 or the materials and thicknesses of each layer 2, 4, 5, 6, and 7, and examples are shown in Table 1 below. The material and thickness may be appropriately selected from those having the materials and thicknesses used in conventional transfer foils.

Furthermore, there is no restriction on the means for forming each layer; for example, it may be formed by a normal coating method such as a solvent coating method (if a wax is used as the release layer 5, a hot melt coating method may be used). good.

The transfer foil of the present invention as described above can be used as a decorative material for replacing metal, such as exterior materials for bicycles and automobiles, labels, name plates, packaging materials for cosmetics, name plates, and various plastic molded products.

It is widely used and is especially suitable for decorative materials that require weather resistance, corrosion resistance, and crack resistance.

Next, the present invention will be described in detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

Example 1 A toluene solution of wax was coated on one side of a 18μ thick polyethylene terrestrial film and dried to form a release layer with a dry layer thickness of 0.5μ, and on top of that was a release layer of thermosetting acrylic resin alcohol-toluene. The solution was applied and dried to provide a transparent resin layer with a dry layer thickness of 1 μm.

Then, using a chromium-bismuth (100:3 (weight ratio)) target, 5×
Input power 65 in 10-3 torr argon gas atmosphere
A thin metal layer having a thickness of 500 mm and having a weight ratio of chromium to bismuth of about 100:3 was formed by sputtering under conditions of 0.0 mm and 2 A.

Furthermore, a toluene-ethyl acetate solution of acrylic acid ester-vinyl chloride copolymer was applied on the thin metal layer and dried to form a heat-sensitive adhesive layer with a dry layer thickness of 1.5 μm, as shown in FIG. We created a transfer foil with a structure like this.

This transfer foil was hot-stamped on the surface of an ABS molded product according to a conventional method.

The transfer layer exhibited a beautiful ROM gloss.

Next, the obtained ABS molded transfer product was subjected to a salt spray test, a thermal cycle test, and a weather resistance test according to the following methods.

(1) Salt water spray test: A cycle of spraying salt water on the ABS molded transfer product for 8 hours and resting for 16 hours was repeated 4 times, and the presence or absence of corrosion was observed.

(2)? lA cycle test: ABS molded transfer product - 130
One cycle consisted of holding at 80° C. for 20 hours, then at room temperature for 4 hours, then at 80° C. for 20 hours, and then at room temperature for 1 hour. After 3 cycles, the presence or absence of cracks was observed.

(3) Weather resistance test: Sunshine Weather Make (
(manufactured by Toyo Rika Kogyo ■) and examined the decrease in metallic luster after 400 hours of exposure.

As a result, ABS molded transfer products suffer from corrosion, cracks, and
No reduction in metallic luster was observed at all.

Example 2 Instead of the thin metal layer of Example 1, chromium-antimony (1
A vacuum evaporation method using an electron beam heating method was used to prepare a mixed powder sintered body with a ratio of 0.00:3 (weight ratio) to a vacuum degree of l.
It was deposited under the conditions of
A transfer foil was produced in the same manner as in Example 1, except that a thin metal layer with a thickness of 0:3 was provided.

After copying the ABS molded product using the obtained transfer foil, the ABS molded transfer product was subjected to a salt spray test, a thermal cycle test, and a weather resistance test in the same manner as in Example 1.

As a result, as in the case of Example 1, no corrosion, no cracking, and no decrease in metallic luster was observed.

Example 3 Chromium and phosphorus are placed separately in two berths, and the vacuum degree is I.
X 10-5 torr, electron power 0.4kW
Simultaneous deposition is performed by irradiating electron beams at a ratio of approximately 100:1, and the ratio of chromium to phosphorus is 10 by weight.
A transfer foil was produced in the same manner as in Example 1 except that a thin metal layer with a thickness of 0:1 was provided.

Using the obtained transfer foil, ABSBS molded product copying, a salt spray test, a thermal cycle test, and a weather resistance test were conducted in the same manner as in Example 1.

As a result, as in the case of Example 1, no corrosion, no cracking, and no decrease in metallic luster was observed.

Comparative Example 1 A transfer foil having a thin chromium layer of 500 mm thick was produced in the same manner as in Example 1, except that a chromium-only target was used in place of the chromium-bismuth target in Example 1.

After transferring to A and BS molded products using this transfer foil, the ABS molded transfer product was subjected to a salt spray test in the same manner as in Example 1.
A thermal cycle test and a weather test were conducted.

As a result, no corrosion or reduction in metallic luster was observed at all, but cracks were observed in one cycle in the thermal cycle test.

[Brief explanation of the drawing]

1 to 4 are schematic enlarged partial vertical cross-sectional views showing typical solid embodiments of the transfer foil according to the present invention, respectively. Drawing code, 1...Base film, 2...
... Transparent or translucent resin layer, 3 ... Thin metal layer, 4 ... Heat-sensitive adhesive layer, 5 ... Release layer, 6 ... ...Metal film protective layer, 7...Static electricity removal layer.

Claims (1)

[Scope of Claims] 1. A transfer foil characterized in that a substantially homogeneous thin metal layer consisting of chromium A and at least one element B of the Va group is provided as the thin metal layer of the transfer foil. 2 The ratio of chromium A to Va group element B is 1 by weight.
00:C), 1 to 100:10. 3. The transfer foil according to claim 1 or 2, wherein the thickness of the metal thin layer is within the range of 200 to 1000 layers.