JPH0420032Y2 - - Google Patents

Description

[Detailed explanation of the invention] A. Industrial application field This invention allows the uniform hue to change in various ways over a wide area by changing the viewing angle, and the iris color can be used in a wide range of fields such as outdoor billboards. The present invention relates to a plate-like object having the following characteristics.

B. Prior Art A familiar example of iris color is the hue of soap bubbles. This is characterized by the fact that the hue changes in various ways when the viewing angle changes, but the reason for the appearance of iris color itself has been known for a long time (for example, Kogoro Yamada's ``Knowledge of Optics'' (Showa era) 43.6.10) Tokyo Denki University Press P234, etc.). In other words, when a transparent thin film layer (interference layer) with an optical thickness equivalent to an odd multiple of 1/4 of a predetermined wavelength is formed, the light reflected on the surface of the interference layer and the light that enters the inside of the interference layer, are reflected on the back surface, and return to the surface. When the incident light is white light such as sunlight, the iris develops an iris color whose hue changes in various ways by changing the viewing angle.

Many examples of iris sheets applying this principle have been proposed. For example, as described in Japanese Patent Publication No. 42-10047, aluminum is vapor-deposited on one or both sides of a film, and then one or two of ZnS, MgF ₂ , AlF ₃ , Sb ₂ O ₃ is deposited on this vapor-deposited surface. Laminated vapor deposition of seeds or more. Or special public service in Showa 47
As described in No. 31107, antimony is vapor-deposited on the surface of a molded product, and then one or more metal compounds of oxygen group elements or halogen group elements are deposited in layers on the vapor-deposited surface. Alternatively, as described in Japanese Patent Publication No. 51-33589, a light reflecting layer is provided on one side of the interference resin film and a semi-transparent metal vapor deposited layer is provided on the other side, and the interference resin film and the semi-transparent metal are provided as necessary. One side or both sides of the molded product are arranged so that the iris layer is formed by repeatedly forming a vapor-deposited film on the semi-transparent metal-deposited film, and the translucent metal-deposited film is located in the direction in which the vapor-deposited film is viewed, and the light-reflecting layer is located in the opposite direction. There are many other proposals such as molded products with iris luster provided in the iris.

C. Problems to be solved by the present invention The iris sheets proposed in the above-mentioned Japanese Patent Publication No. 42-10047 and Japanese Patent Publication No. 47-31107 do not have sufficient iris color expression effect, and their surface strength is also weak. However, it had the disadvantage that its surface was easily attacked by chemicals and its weather resistance was poor. In order to improve this problem, applying a surface protective coating or laminating a plastic film could be considered, but this naturally increases the number of steps and increases costs.

In addition, since the iris sheet disclosed in Japanese Patent Publication No. 51-33589 uses a resin film to form an interference layer of several thousand angstroms, it is difficult to control the thickness of the resin film uniformly over a wide area. It had the disadvantage that it was not possible to develop a uniform iris color.

D. Means for solving the problems The present invention was made to solve the above-mentioned drawbacks of the prior art.The gist of the invention is explained with reference to FIG. 1. The semi-transparent layer 2 and the so-called vacuum deposition method, sputtering method, ion plating method, etc.
PVD method (physical vapor deposition method)
One or more layers of light interference layer 3 made of The object is to obtain a plate-like object having iris colors on both sides.

The plastic film 1 is normally a colorless film with a white light transmittance of 80% or more, but it may be slightly colored. When colored, a unique iris effect can be obtained. The types of plastic films that can be used include polyethylene terephthalate film, polyethylene film, polypropylene film, polycarbonate film, polyvinyl chloride film, nylon film, and cellophane.
A thickness of 5 μm to 100 μm is used.

The light semi-transparent layer 2 is made of aluminum, gold, silver, copper,
Metals such as tin, chromium, titanium, nickel, and cobalt are formed by known means such as vacuum evaporation, sputtering, and ion plating, but even if the film is too thin or thick, it will not function properly. Normally, the transmittance of white light is
Formed in 10-55%. The relationship between the light transmittance and the thickness of the semi-transparent layer varies depending on the metal used, but for example, in the case of an aluminum thin film, the transmittance is approximately 200% at a transmittance of 10%.
Å 55% corresponds to a thickness of 50 Å.

The optical interference layer 3 is made of ZnS, Sb ₂ O ₃ , Cu ₂ O, ZnO,
_SiO2 , SiO, _Al2O3 , _{In2O3 , SnO2} , _TiO2 , _TiO ,
Inorganic compounds such as MgO and CdS are formed using so-called PVD methods such as vacuum evaporation, sputtering, and ion plating, but iris color will not appear even if the thickness is thin or thick. It forms in the range of 1500 Å to 25000 Å.

At this time, it is necessary to control the thickness so that it is an odd multiple of 1/4 of the predetermined wavelength. If the interference layer is formed of a resin coating layer as shown in Japanese Patent Publication No. 51-33589, it is extremely difficult to uniformly control the interference layer over a wide area so that the wavelength is an odd multiple of 1/4 of the predetermined wavelength. It is. In comparison, so-called vacuum deposition methods, sputtering methods, ion plating methods, etc.
In the PVD method, the substance that forms the interference layer is attached to the substrate in the form of molecules, atoms, or ions in a high vacuum of 10 ^-3 to ^{10 -6} mmHg, making it easy to obtain uniform film thickness. It has the greatest characteristics and is an essential method to achieve the present invention. One or more light semi-transmissive layers and interference layers are formed. An example of two layers is shown in FIG. 2; in this case, the iris-revealing effect is greater than that of one layer. In this case, the materials used may be changed. In the present invention, it is necessary to further form a light reflecting layer 4 on the interference layer, so that the light reflected on the surface of the semi-transparent layer and the light that once enters the interference layer, is reflected by the reflective layer, and then re-transmitted. Interference occurs with the light that emerges from the surface, resulting in the creation of highly concentrated and beautiful iris colors. The light reflecting layer is made of aluminum or aluminum by known means such as vacuum evaporation, sputtering, or ion plating.
gold, silver, copper, tin, chrome, titanium, nickel,
It is formed from cobalt, etc., but if the thickness is too thin, the light reflecting effect will be reduced, and if it is too thick, it will be a waste of material and the line speed will decrease, so it is usually formed in the range of 300 Å to 1000 Å. . In the present invention, the iris film thus obtained is bonded to a plate-like object 6 such as paper, metal plate, plastic plate, etc. through an adhesive layer 5 so that the light reflecting layer is in contact with the adhesive. In this case, the adhesive must not corrode the reflective layer even after a long period of time, and depending on the application, it is necessary to select a water-resistant adhesive. In addition, by pasting it onto the screen of a plate-like object as shown in FIG. 3, it is possible to make the iris color appear on both sides.

E. Functions and Effects Since the present invention has the structure described above, it has the following functions and effects.

1. Extremely beautiful iris color appears uniformly over a wide area.

2. Since the plastic film surface is on the surface, it has excellent mechanical strength, and by selecting a film with chemical resistance, a surface with excellent chemical resistance can be easily obtained.

3. Many of the metals used for the semi-transparent layer and the reflective layer corrode if left in the air for a long time, but in this invention, the semi-transparent layer and the reflective layer are protected by the film surface and the adhesive layer. It has excellent corrosion resistance and weather resistance.

4. Since it is a plate-shaped product, it can be easily processed. Bending can be easily performed when combined with a metal plate. Also, punching can be easily performed.

The iridescent plate obtained by this invention can be used for interior materials for show windows, indoor and outdoor billboards, exterior materials for furniture and home appliances, toys, and many other uses by taking advantage of its properties. .

F. Examples Example 1 Metal aluminum was deposited to a thickness of 150 Å onto a biaxially stretched polyester film having a thickness of 12 μm using a resistance heating vacuum deposition apparatus. Next, an interference layer made of SiO ₂ with a thickness of 4000 Å was formed using an electron beam heating type vacuum evaporation apparatus. In addition, using a resistance heating type vacuum evaporation machine, a thick layer made of metal aluminum is produced.
A light reflecting layer of 500 Å was formed. The iris film thus obtained was laminated with a 0.2 mm thick aluminum plate using a laminator using polyurethane resin. The plate-shaped article having an iris color obtained as described above had a uniform iris color over a wide area, had strong surface strength, and was excellent in water resistance and weather resistance.

Example 2 An interference layer made of Al ₂ O ₃ instead of SiO ₂ in Example 1 was formed using an RF sputtering device. The resulting iris-colored plate had the same performance as Example 1.

[Brief explanation of the drawing]

1 to 3 are partially enlarged sectional views showing an embodiment of the present invention. FIG. 1 shows an example in which there is only one light transmissive layer and one interference layer. FIG. 2 shows an example in which there are two layers, a semi-transmissive layer and an interference layer. FIG. 3 shows an example in which iris sheets are pasted on both sides of a plate.

Claims (1)

[Scope of utility model registration request] On a transparent plastic film 1, a light semi-transparent layer 2 and one or more light interference layers 3 formed by a so-called PVD method such as a vacuum evaporation method, a sputtering method, or an ion plating method are formed. A plate-shaped article having an iridescent color on one or both sides, characterized by forming a reflective layer 4 and bonded to a plate-shaped article 6 via an adhesive layer 5.