JPS6115962A - Formed part having iris luster - Google Patents

Abstract

PURPOSE:To provide a titled formed part which has the iris colors formed by effective light interference and is stable and easy to work by providing the iris layer laminated with a ray reflective film, thin transparent film consisting of a metallic compd. and a translucent metallic film deposited by evaporation in this order on one or both surfaces of the formed part. CONSTITUTION:The iris layer formed by laminating >=1 layers of the thin transparent film consisting of the metallic compd. such as Al2O3, TiO2, SiO2 or ZrO2 having about <=5,000Angstrom optical thickness and preferably about >=60% visible ray transmittance and the thin translucent metallic film deposited by evaporation of Au, Ag, Al, Cu, Sn, etc. to about >=350Angstrom film thickness and having about 20-70% visible ray transmittance on one surface of the ray reflective film consisting of metallic foil or Al, Ag, etc. or the opaque metallic film deposited by evaporation to about >=350Angstrom film thickness in this order is provided on one or both surfaces of the formed part of a film, sheet, paper, etc. by which the formed part having iris luster is obtd. The above-mentioned iris layer is so provided that the ray reflective film is positioned on the outside on one side of the molding if the formed part is transparent of translucent and said layer is provided on the opposite side thereof if said layer is opaque to position always the translucent metallic film deposited by evaporation on the side to be viewed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a molded product that exhibits beautiful iris colors due to optical interference.

[Conventional technology]

Conventionally, various methods have been known in which interference S* is provided on the surface of a molded product such as a film to make the iris color appear. In most cases, metal compounds such as halides, oxides, and sulfides are simply formed on the surface of the molded product to form a thin film corresponding to the optical thickness by vapor deposition, chemical reaction, or resin coating.

When the light rays reflected from the upper and lower surfaces of the am interfere with each other with a phase difference, it is perceived by the human eye as an iris color. Its hue varies depending on the viewing angle, and its saturation is most beautiful when the reflectance of the incident light on the top surface is equal to the reflectance on the bottom surface.

For example, according to Japanese Patent Publication No. 37-8731, an iris-colored film is known in which titanium tetrachloride gas is sprayed from a nozzle onto the surface of a polyester film to form a monolayer film of titanium oxide.

Generally, when a single layer film of a certain thickness is provided on the surface of a base material,
As the refractive index becomes larger than the refractive index of the base material, the change in energy reflectance due to phase change becomes larger. Therefore, in order to produce a highly saturated iris color in such a configuration, it is necessary to increase the difference in refractive index between the single layer film and the base material.

Furthermore, according to Japanese Utility Model Publication No. 44-27173, a material exhibiting an iris color is known, which has a structure in which a thin film of Pb 3r 2 is provided on a base film with a vapor-deposited layer of Sn, Cr, Aa, and At interposed therebetween. ing.

However, in such a configuration, the reflectance on the bottom surface of the I film is significantly higher than the reflectance on the top surface of the I film, so the interference is weakened and the only visible iris color is a glare with poor hue. .

(Problems to be Solved by the Invention) The purpose of the present invention is to solve the problems of the prior art described above, to find a configuration for expressing iris color through effective optical interference, and to apply this to molded products. be.

[Means for solving problems]

The present invention provides an iris layer having a structure in which at least one layered film is provided on one side of a light reflecting film, in which a transparent metal compound film and a semi-transparent metal vapor deposited film are stacked in this order from the side of the light reflecting film. The iris is provided on one or both sides of the molded product such that the uppermost translucent metal vapor-deposited film is located on the viewing side and the light reflecting film is located on the opposite side. This provides a molded product with gloss.

[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 metal mirror, and the optical thickness (nd) of this transparent thin film corresponds to an odd multiple of a quarter wavelength. This takes advantage of the fact that the reflectance of light at that wavelength is at its maximum when 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 change in reflectance with respect to wavelength, the better the characteristics in a narrow band.

(Embodiment) As the metal compound transparent thin film used in the present invention, for example, a thin film of a metal oxide such as aluminum oxide, titanium oxide, silicon oxide, or zirconium oxide is used, and the thickness thereof is an optical thickness of 5,000 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 (CVD) method is appropriately used.

The translucent metal vapor-deposited film is made of All, AQ, AI, and Q films with an average light transmittance of 20 to 70% in the visible light band.
It is a thin metal vapor deposited film consisting of u, 9n, etc. The light reflecting film is a metal foil such as AI or AQ, or an opaque metal vapor deposited film having a thickness of about 350 mm or more. Molded products are secondary products such as films, sheets, and paper.

An iris layer consisting of the above-mentioned layers is formed on the surface of the molded article.

That is, when making an iris color appear on one side of a transparent or translucent molded product, first a translucent metal vapor-deposited film with a light transmittance of 20 to 10% in the visible light band is applied to one side of the molded product, and then a film is applied to one side of the molded product. A metal compound transparent thin film having a thickness of 5000 Å or less is provided.

Further, if necessary, the translucent metal vapor deposited film and the metal compound transparent thin film are successively formed one more layer at a time, or a plurality of layers at a time, and finally a light reflecting film is provided. In this configuration, the iris color is confirmed through the molding. In addition, when an iris color is to appear on one or both sides of an opaque molded product or on both or one side of a transparent molded product, a light reflecting film is first provided on one or both sides of the molded product. Next, a metal compound transparent thin film with a film thickness of 5000 Å or less and a translucent metal lid @ film with a light transmittance of 20 to 70% are sequentially formed,
The metal compound transparent thin film and the semi-transparent metal vapor deposited film are sequentially and repeatedly formed as necessary.

In actual processing, ordinary continuous or semi-continuous vapor deposition equipment, coaters, etc. can be used as they are. The light transmittance of the semi-transparent metal vapor deposited film greatly affects the iris effect, so it is desirable to keep it within a predetermined range as much as possible. As long as the molded product is transparent, a light source can be provided on the back side of the molded product, and a translucent metal vapor deposited film can be formed while detecting the transmitted light photoelectrically from the front side. However, by creating transmittance-thickness curves for each metal in advance,
If vapor deposition is performed based on this, the work can be easily carried out regardless of the type of molded product. The deposition materials for forming the semi-transparent metal deposition film include AI and AQ, which are relatively easy to use in continuous or semi-continuous deposition.

Even by simply selecting one of the metals such as Cu, an iris color with a rich variety of tone can be obtained due to the light absorption characteristics specific to each metal.

Furthermore, 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 obtain various tones of iris color depending on the viewing angle. For example, if the optical thickness (nd) of the thin film is an odd number multiple of 550 nm 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 change to green, blue, etc. The iris has a wide variety of colors, including purple.

In addition, 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 change It is possible to create anything you like.

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 (film thickness of 500 Å or more); the larger the N (the larger the film thickness), the better the Although it shows angular dependence, it is actually 41 (approximately 5 in film thickness)
000^) is the limit, and if it becomes larger than that, cracks will naturally occur due to the internal stress of the metal compound thin film, and the iris color will deteriorate significantly.

In addition, when providing multiple layers of metal compound transparent WI film,
The optical thicknesses of the upper and lower layers must be set so that interference is emphasized in the laminated state. The iris color is
Compared to the case where a single layer of the thin film is provided, the hue becomes more diverse and the interference fringes intersect, resulting in an unusual iris color change due to various composite colors.

The molded product having iris luster thus obtained not only exhibits an unprecedentedly vivid iris color, but also is stable and easy to process, making it extremely suitable for mass production.

〔Example〕

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

Example 1 A1 vapor deposition was performed continuously on one side of a transparent long polyethylene terephthalate film (thickness 25μ),
A so that the light transmittance at a wavelength of nm is 35%.
1 vapor deposition layer was formed. Next, SiO2 was deposited using a high-frequency induction heating vacuum evaporation method with the film thickness being continuously changed in the range of 600 to 5,000^, and A1 was further deposited to a film thickness of 500 to form a light reflecting film.

The iris effect and film properties of the iris film obtained as described above were examined. The results are shown in Table 1.

The iris color was determined based on the following criteria.

◎・・・Very good hue and saturation O...Good hue and saturation Δ...Both hue and saturation are inferior ×...Iris color is extremely poor The film quality was determined based on the following criteria.

◎...Normal O...Slight cracking ×...Cranking The base color varies depending on the thickness of the film, and changes continuously from purple to red depending on the film thickness.
From the viewpoint of obtaining an iris color that varies in tone depending on the viewing angle, which is the main objective of the present invention, the thickness of the thin film is preferably 1000 Å or more, and the thicker the thickness, the more diverse iris effects can be obtained.

It should be noted that if the thickness of the thin film exceeds 5,000 mm, cracks are observed to occur due to internal stress in the deposited film, which is not preferred in practice.

Example 2 A light reflecting film was provided on the resin film surface of a long sheet of paper coated with a resin by continuously performing A1 vapor deposition to a film thickness of 600. ZrO2 was deposited on the light reflecting film to a thickness of 1200 mm by electron beam evaporation to form a metal compound m film.

Furthermore, an A1 vapor-deposited film having a thickness of about 70 mm (thickness corresponding to a monochromatic light transmittance of about 40% by a sodium lamp) was formed on the thin film.

When viewed from the front, this iris paper exhibits an emerald color with a green tone, and when viewed from a different angle, it changes to gold, blue, and more.
It was extremely beautiful, with an iridescent color that changed to purple.

the law of nature【

Claims (1)

[Scope of Claims] 1. A structure in which at least one layered film is provided on one side of a light reflecting film, in which a metal compound transparent thin film and a semi-transparent metal vapor deposited film are stacked in this order from the light reflecting film side. The iris layer is provided on one or both sides of the molded product such that the uppermost translucent metal vapor-deposited film is located on the viewing side, and the light reflecting film is located on the reflective side. A molded product with an iris luster. 2. The molded product according to claim 1, wherein the molded product is transparent or translucent, and the iris layer is provided on one side of the molded product so that the light reflecting film is on the outside. 3. The molded product according to claim 1, wherein the iris layer is provided on one or both sides of the molded product such that the light reflecting film is on the side of the molded product.