JPS6116900A - Transfer foil displaying iris gloss - 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 [Field of Industrial Application] The present invention relates to a transfer foil for producing iris colors with high saturation and rich hue through optical interference.

[Conventional technology]

Traditionally, gold and silver foils have been the mainstream in the field of transfer foils,
In addition to colored areas, transfer foils are known to produce special effects such as wood grain patterns and irises.

In particular, as for the transfer foil that produces the iris effect, it is preferable to use a thin light interference film because the hue is natural and changes depending on the viewing angle. .

Transfer foil using this interference thin film contains halide,
Although it has a single layer film of metal compounds such as oxides and sulfides, its iris luster is not always satisfactory.

[Problem that the invention attempts to solve]

An object of the present invention is to solve the problems of the prior art and provide a transfer foil exhibiting even more beautiful iris luster.

(Means for Solving the Problem) The present invention provides a laminated structure in which a translucent metal vapor deposited film and a metal compound transparent thin film are laminated in this order from the base film side on a base film having mold releasability. The present invention provides a transfer foil exhibiting iris luster, which is provided with at least one film, and a light reflecting film and an adhesive layer are sequentially provided on the uppermost metal compound transparent thin film of the laminated film.

[For production]

The basic principle for developing iris color in the present invention is based on a reflective interference filter.

A reflective interference filter consists of a transparent thin film and a semi-transparent film stacked one after another on a gold IT mirror, and the optical thickness (nd) of this transparent thin film is equivalent to an odd multiple of a quarter wavelength. This method takes advantage of the fact that when the wavelength of light reaches a maximum, the reflectance of light at that wavelength is at its maximum. In other words, if the optical thickness of the thin film is set to an odd multiple of 1/4 of the wavelength of the light you want to selectively reflect, the reflectance of light of other wavelengths will decrease, but only the light of the desired wavelength will be reflected. It reflects maximum and can be obtained selectively. In this type of filter, the larger the reflectance change with respect to wavelength, the better the characteristics in a narrow band.

When the transfer foil having the above structure is used, an iris-colored pattern with even better hue and saturation can be produced on the transferred object due to optical interference.

[Embodiment]

Next, the present invention will be explained based on the drawings.

FIG. 1 is a sectional view showing one embodiment of the transfer foil of the present invention, and FIG.
The figure is a schematic explanatory view showing a state immediately after transfer using the transfer foil of the present invention.

The transfer foil (A) in Fig. 1 is made by providing a release layer (2) on a base film (1), and then a semi-transparent metal vapor deposited film (3) on the release layer (a) and a metal compound transparent thin film (3) on the release layer (a). 4), light reflecting film (
5) and an adhesive layer (6) were formed in this order.

The base film (1) is a plastic film such as polyethylene terephthalate or polycarbonate with low water absorption and high heat deformation resistance, paper, cellophane, or metal foil. The release layer (2 is an uncolored transparent or colored transparent coating layer made of acrylic resin, acetyl cellulose, acetyl butyl cellulose, etc.).

The semi-transparent metal vapor deposited film (3) is made of AI, Ag, and has a film thickness with a transmittance of about 20 to 70% for sodium monochromatic light.
, Au 1Cu , Sn or the like.

As the metal compound transparent thin film (4), a thin film of metal oxide such as aluminum oxide, titanium oxide, silicon oxide, zirconium oxide, etc. is used, and its thickness is 500 mm.
Preferably it corresponds to an optical thickness of 0 Å or less. The transparency is preferably 60% or more expressed as an average transmittance of light in the visible light band.

For forming such a metal compound transparent thin film, a physical vapor deposition (PVD) method such as a vacuum evaporation method, a sputtering method, an ion blating method, or a chemical vapor deposition (CVO) method is appropriately used.

The light reflecting film (5) is a metal vapor deposited film having a thickness of approximately 350 mm or more and is made of AI, Al11, etc. with high reflectivity.

The adhesive layer (6) is made of polyvinyl acetate, polyvinyl chloride,
It is a heat-sensitive adhesive layer such as polyacrylic acid ester, or a pressure-sensitive adhesive layer made from a base of natural resin, polyvinyl ether, etc.

Transfer foil is manufactured by sequentially laminating each of the above films and layers, but during actual processing, continuous or semi-continuous vapor deposition equipment and resin coaters can be used as is, as in conventional methods. can. If metal foil is used as the base film, not only will the amount of outgassing be reduced and the vapor deposition process will proceed more easily, but also the transfer time can be shortened due to its high thermal efficiency. Further, as the adhesive layer, both the heat-sensitive type and the pressure-sensitive type can be used as described above, and in the case of the pressure-sensitive adhesive layer, it is covered with a release paper. These types can be selected as appropriate depending on the purpose and method of use.

Furthermore, the effects of the present invention can be further improved if the following points are taken into consideration in processing.

(1) As is clear from the principle of the reflection type filter described above, even if the thickness of the metal compound thin film is constant, it is possible to vary the iris colors to various tones depending on the viewing angle. For example, if the optical thickness (nd) of the thin film is an odd multiple of 550 nl x 1/4, it will have a golden tone when viewed from the front, but as you change the viewing angle by about 15 degrees, it will turn green and blue. A wide variety of iris colors can be obtained, such as changing from , to purple, etc.

Also, as can be easily estimated from the formula nd = 1/4λ (λ: wavelength of light), by changing the thickness of the thin film, it is possible to create green-based, blue-based, and purple-based images when viewed from the front. It is possible to create anything you want.

In order to make the angular dependence of the iris color more noticeable, the formula nd-N
If N in X 1/4λ (N: odd number) is 1 to 3, it is insufficient; it must be at least 5 or more (II thickness is 500 Å or more), and the larger N is (the larger the film thickness)
Although it shows good angle dependence, the practical limit is 41 (approximately 5,000 in film thickness), and if it becomes larger than that, cracks will naturally occur due to the internal stress of the thin metal compound film, and the iris color will deteriorate significantly. It's coming.

(The film thickness of the '2I semi-transparent metal film is such that when the transmittance of sodium monochromatic light irradiated from the back side of the base film provided with the release layer is 100, the transmittance is 20 By setting the film thickness within a range that attenuates the film by ~70%, or by setting the deposition conditions based on the relationship between the transmittance of the deposited film and the film thickness when deposited on a transparent medium where light absorption is completely negligible. Determine the film thickness. These methods can be selected depending on the type of base film. If the base film is transparent, the former method is preferred, and if the base film is opaque, the latter method is preferred.

(3) Excellent iris color can be obtained by alternately stacking a plurality of translucent metal vapor-deposited films and transparent metal compound thin films. In that case, if the optical thickness of the upper and lower layers of the transparent metal compound film is set so that the interference is emphasized in the laminated state, that is, the phase change is large to cause optical interference, the iris color will be monotonous. Compared to layered films, the hues are more diverse, and the interference fringes intersect, resulting in an unusual iris color change due to various composite colors.

(4) If a colored transparent resin layer is interposed between the release layer and the semi-transparent metal vapor deposited film, it is possible to vary the iris color based on the coloring effect.

(9) Even if the deposition material is selected from AI, Cu, Ao, etc., which are relatively easy to use in continuous or semi-continuous deposition, the hue of the iris color will change due to the light absorption characteristics unique to the metal. .

To perform transfer using the transfer foil of the present invention, as in the conventional method, one adhesive side of the transfer foil is placed on the surface of the molded object, and pressure is applied from the base film side with a heated stamp or rubber. For example, the transfer layer where heat and pressure are applied instantaneously,
It is separated from the base film and transferred to the surface of the molded product.

FIG. 2 schematically shows the state immediately after iris characters are transferred to the protrusions of a molded article using the transfer foil of the present invention. In the figure, (
The force is rubber, and (8) is the molded product after transfer.

The transfer foil of the present invention not only exhibits an unprecedentedly vivid iris color, but is also stable and does not require any special techniques for processing.

-81 The transfer foil of the present invention can be widely applied not only to conventional uses such as plastic molded products, but also to clothing, accessories, and other decorative uses.

[Examples] Next, the present invention will be explained with reference to Examples, but the present invention is not limited to these Examples.

Example 1 A 15 il % toluene solution of polymethyl methacrylate was coated on a long transparent polyethylene terephthalate film (thickness: 16 μm), and then baked and dried to form a release layer. AI thermal evaporation was performed on the release layer to form a translucent metal evaporation material such that the monochromatic light transmittance of a sodium lamp provided on the back side of the film was 35%. On the semi-transparent metal vapor deposited film, 8102 was vapor deposited by high frequency induction heating vacuum evaporation method with the film thickness continuously changed in the range of 600 to 5000 to form a metal compound transparent thin film.

On the obtained transparent thin film of metal compound, A1 was deposited to a thickness of 500 ml to form a light reflecting film. A 7% by weight solution of polyvinyl acetate in a mixed solvent of toluene and methyl ethyl ketone was applied onto the rough reflective film and dried with hot air to form an adhesive layer to obtain a transfer foil.

Transfer was performed using the transfer foil obtained as described above, and the iris effect and film properties of the transfer layer were examined. The results are shown in Table 1.

The iris color was determined based on the following criteria.

◎: Both hue and saturation are extremely good. ○: Both hue and saturation are good Δ: Both hue and saturation are inferior ×: Extremely poor iris color The film quality was determined based on the following criteria.

◎: Normal ○: Slight cracking ×: Cracking [blank below] Table 1 As is clear from the results in Table 1, the iris color of the transfer layer is
The basic color varies depending on the thickness of the metal compound thin film, and changes continuously from purple to red depending on the film thickness.However, from the viewpoint of obtaining an iris color that changes in tone depending on the viewing angle, which is the main objective of the present invention, the basic color of the thin film is The thickness is preferably 1000 Å or more, and the thicker the thickness, the more diverse the iris effects can be obtained. It should be noted that if the thickness of the thin film exceeds 5,000 layers, cracks are observed to occur due to internal stress in the deposited film, which is not preferred from a practical standpoint.

Example 2 In Example 1, a semi-transparent metal vapor deposited film was formed with a thickness of approximately 70 mm (
The film was replaced with an AI vapor-deposited film (thickness equivalent to about 40% monochromatic light transmittance using a sodium lamp), and the metal compound transparent thin film was replaced with a ZrO2 vapor-deposited film (formed by electron beam evaporation) with a film thickness of about 1200 mm. A transfer foil was produced in the same manner as in Example 1 except for the above.

When transferred using this transfer foil, the iris color of the transfer layer exhibits an emerald color with a green tone when viewed from the front, and an iridescent color that changes to gold, blue, and purple when viewed from a different angle.It is extremely beautiful. It was something.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing one embodiment of the transfer foil of the present invention, and FIG.
The figure is a schematic explanatory view showing a state immediately after transfer using the transfer foil of the present invention. (Main symbols in the drawings) (1) Two-base film (3) Two-handed transparent metal vapor deposition film (4): Metal compound transparent thin film (5): Light reflecting film (6): Adhesive layer

Claims (1)

[Claims] 1. On a base film having mold releasability, at least one layer of a laminated film having a structure in which a translucent metal vapor deposited film and a transparent metal compound thin film are laminated in this order from the side of the base film is provided, and the uppermost layer of the laminated film is A transfer foil exhibiting iris luster, which is formed by sequentially providing a light reflecting film and an adhesive layer on a transparent thin film of a metallic compound.