JPH0491875A - Rainbow color developable metallic ornament - Google Patents

Abstract

PURPOSE:To impart the high-grade sense sufficient as the ornaments without impairing rainbow color development by providing noble metals at the thickness to allow rugged ness to remain on the surface formed with the fine ruggedness formed in accordance with the intensity distribution of the interference fringes of laser beams on the surface of a metal, such as stainless steel. CONSTITUTION:The movement in both X and Y directions of an X-Y table T is cooper atively controlled or the optical axis direction of the interference beam B1 is changed by an optical control mechanism, such as X-Y scanner, by which scanning lines can be set to a curved shape or so set as to draw locis constituting intricate patterns. The fine ruggedness U1, U2 corresponding to the intensity distribution of the interfer ence fringes of the laser beams M1, M2 are formed on the surface of the metal M consisting of the stainless steel or Ni-Cr alloy. The noble metal film G is provided on the surface formed with such fine ruggedness U1, U2 at the thickness at which the ruggedness remains on the surface. Then, the unique beautiful ornamentation changing variously in tint like rainbow colors is applied on the surface and the noble metallic gloss specific to the noble metal G is produced as the scattering reflection of the surface inclusive of the ornamented part. The metallic ornaments having the extremely high sense are thus provided.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a metal whose surface is uniquely decorated so that the tint of its reflective luster changes in a rainbow-like manner depending on the angle of incident light and the viewing direction. Concerning ornaments.

(Prior Art) The present applicant previously proposed Japanese Patent Application No. 1-84326 and Japanese Patent Application No. 1-84326 as a first stage of decoration to give a metal surface beautiful multi-color variable color development which is impossible with painting or chemical coloring. There is a laser pressurization method proposed in No. 229567, in which fine irregularities corresponding to the intensity distribution of interference fringes are formed on a metal surface by irradiation with laser interference light.

In other words, the fine irregularities formed by the method described in Section 2 are normally 1μ in diameter, with hundreds of irregularities formed on each scan line of the laser interference light, with the bright areas of the interference fringes being concave and the dark areas being convex. Visible light wavelength range (3800 nm or more)
~7,800 people) gathered closely at pitch intervals. Therefore, a metal surface with such fine irregularities splits and reflects incident light in the same way as a diffraction grating, and the tint of the reflected luster changes in a rainbow-like manner depending on the direction of the incident light and the viewing angle. Become.

In addition, as a structure to obtain rainbow-like reflective gloss similar to the above, by forming minute irregularities on the back side of a transparent synthetic resin plate and providing a reflective layer such as aluminum foil on the back side,
A device that performs spectral reflection using a so-called prism effect is known. However, the reflective gloss obtained with such a structure has better clarity, brightness, and spectral color than the reflective gloss obtained when fine irregularities are directly formed on the metal surface using the laser interference light described above. Significantly inferior in all aspects.

(Problems to be Solved by the Invention) As mentioned above, beautiful iridescent coloring can be obtained by forming fine irregularities on the metal surface that correspond to the interference fringes of laser interference light, but at present, there are no surface treatments for metals. Stainless steel and Ni-Cr alloys are examples of metal materials that can easily and reliably form the above-mentioned fine irregularities with a general laser processing machine such as a YAC laser widely used in the industry.

However, although the above-mentioned stainless steel and Ni-Cr alloy have an extremely beautiful iridescent reflective luster, they reflect scattered light, that is, the base color looks cheap, and when used as an ornament, it gives a luxurious impression. I don't like being lacking.

In view of the above-mentioned circumstances, the present invention uses stainless steel or a Ni-Cr alloy as the metal material to which the iridescent coloring process is applied, and also imparts a high-class feel sufficient to be used as a decorative item without impairing the iridescent coloring property. The purpose is to

(Means for Solving the Problems) As a means for achieving the above object, the iridescent metal ornament of the present invention is characterized by the intensity distribution of interference fringes of laser light on the surface of a metal made of stainless steel or NiCr alloy. A structure is adopted in which corresponding fine irregularities are formed and a precious metal coating is provided on the surface on which the fine irregularities are formed with a thickness that leaves the irregularities on the surface.

Further, in the present invention, a preferable embodiment is the structure of claim (2), wherein the noble metal coating in the decorative article is a thin film having a thickness of 1 μm or less and made of a metal selected from gold, silver, and platinum.

(Function) The fine irregularities provided on the surface of a metal made of stainless steel or Ni-Cr alloy correspond to the intensity distribution of interference fringes of laser light, and are disclosed in the above-mentioned Japanese Patent Application No. 1-84326.
It can be easily formed by the laser processing method using laser interference light irradiation disclosed in No. 1 and Japanese Patent Application No. 1-229567.

As mentioned above, the metal surface with the fine irregularities exhibits a reflective luster whose hue changes in a rainbow-like manner depending on the angle of incident light and the viewing direction. Also, the appearance of the above-mentioned fine irregularities on the surface of the coating produces a beautiful iridescent reflective gloss. However, the color of the scattered light reflection, that is, the color of the metal surface that does not produce the above-mentioned rainbow-like coloration based on the spectrum, reflects the ground color of the precious metal itself.For example, gold has a golden color, and silver and platinum have a faint color. It exhibits a unique dull white silver color with low reflectance, giving it a luxurious feel as a decorative item. In addition, the hue of the iridescent emitted luster produced by spectroscopy is also affected by the ground color of the precious metal. For example, if the precious metal is gold, the entire color that changes will have a reddish tinge, while if the precious metal is gold, the color will have a reddish tinge, while if it is silver or platinum, it will have a reddish tinge. Coloring is produced, and in both cases, a more profound beauty is added than the hues produced on the surfaces of stainless steel and Ni-Cr alloys.

The thickness of the noble metal coating as in No. 2 is preferably 1 μm or less; if it is too thick, the fine irregularities of the base will be buried, the irregular stripes on the surface will become blurred, and it will be difficult to produce a good iridescent color. Note that this thickness may be made thin enough to allow the base color of the underlying stainless steel or Ni-Cr alloy to be seen through.

(Example) Hereinafter, the present invention will be specifically described based on illustrated examples.

Figure 1 shows the laser processing process, and the ZY table T
A metal plate M made of stainless steel or Ni-Cr alloy is placed on top of the metal plate M, and the interference light B1 of the laser beam is focused by a processing condensing lens L provided above the metal plate M, and the interference light B1 is focused beyond the focal point of the lens L. The surface of the metal plate M is irradiated at a far position. Therefore, by moving the XY table T in the X direction, the surface of the metal plate M is scanned by the converged interference light B2, so the XY table T must be moved in the Y direction every time this scan is completed. A parallel linear or planar scanning pattern can be obtained. Therefore, every 4 scans, the surface of the metal viM has interference fringes with a 1" cross-pattern within the width of the irradiation spont diameter, as shown in the enlarged view of the imaginary line circle C in Fig. 1. Hundreds of four stripes I corresponding to the bright areas are formed.

The interference light B, as disclosed in the above-mentioned Japanese Patent Application No. 1-84326, is obtained by the mutual overlap of bright pattern components in a 1° laser beam of low-order Fultimo l, or by the overlap of bright pattern components in a single laser beam. A plurality of divided beams J can be constructed by overlapping each other, or by laterally displacing the part of the laser beam, as disclosed in Japanese Patent Application No. +1-229567 mentioned above. It can be constructed by superimposing it on the original beam component. The specific device configurations for collecting these interference lights B are also disclosed in the above-mentioned patent applications.

Note that by controlling the movement of the XY table T in both the X and Y directions in conjunction with each other, or by changing the optical axis direction of the 1-beam beam B1 using an optical control mechanism such as an It can be set so as to draw a pattern-like locus, and furthermore, by a combination of two-way orientation means, it is possible to create fine irregularities on a two-dimensional metal surface such as a curved surface.
Also possible 1]: 5°.Also, the irradiation position of the interference light +32 may be set at a position shallower than the points I and D of the lenses 1-. A concave mirror can also be used as a convergence means for (, kaj-ko)-light beam B,.

Thus, the surface Q of the metal plate M is formed with fine irregularities (51) consisting of a large number of dense four stripes 14 as shown in the second figure. 2. Forming a precious metal coating on the surface.In addition, in the figure, the 1-year-old model i: Aim 4.As shown, the grooves I',j of each minute unevenness tJ are actually as described above. It's a few scoops.

This precious metal coating needs to be thick enough to leave fine irregularities based on the fine irregularities of the ground (a) on the surface of (a), and in particular, it is desirable to have a thickness of 1 J7111 or less without leaving any clear uneven stripes. .

However, as a means of forming such a thin noble metal film, 1. A method for forming a thin film using the IIT product in a high vacuum such as vacuum evaporation, sputtering, and ion blating. In addition, electrochemical methods such as electrolytic agate can also be used, but the former method of forming a thin film is particularly preferred in terms of uniformity of the film.

In addition, f1' metals that form thin films include gold, silver,
Platinum is preferred.

FIG. 3 shows an iridescent metal ornament of the present invention obtained as described above, in which the entire surface of a metal plate M made of stainless steel or N1-C+ alloy has the fine irregularities I. A noble metal thin film G is formed over the entire region, and the surface of this thin film G has fine unevenness portions 1 and 2 in which grooves formed by each of the four threads I are faithfully expressed at the positions of the fine unevenness portions U1. However, this fine unevenness U2 has a reflective luster whose hue changes in a rainbow-like manner depending on the angle of incident light and the direction in which it is viewed, and in terms of scattered light reflection, it has a precious metal like other surface areas. It exhibits a characteristic noble metallic luster.

In addition to forming such fine irregularities U in a line shape such as a picture pattern or a geometric pattern, they may be formed densely to produce iridescent coloring on a surface.

The ornaments to which the present invention is applicable include, for example, high-quality metal accessories such as tie bins, earrings, rings, clock faces, cases, ornaments, and other metal arts and crafts. products, high-grade metal tableware such as spoons, forks, knives, and plates, exterior metal parts of various indoor electrical appliances, metal parts of high-grade furniture, various metal--business supplies and parts, etc., with decorative functions. Includes all metal products and parts.

(Effects Unique to the Invention) According to the present invention, an inexpensive metal material made of stainless steel or a NiCr-based alloy can be used as a line pattern or blood pattern on the surface, the color of which changes depending on the angle of incident light and the viewing direction. It has a unique and beautiful decoration that changes in various colors like a rainbow, and the surface including the decoration part reflects the scattered light, giving it a noble metallic luster that is unique to precious metals, giving it a very luxurious feel. We can provide metal 2 ornaments.

Further, according to the structure of claim (2) of the present invention, there is an advantage that the rainbow-like coloring of the decoration is particularly clear and adds a sense of luxury.

[Brief explanation of drawings]

Fig. 1 is a schematic perspective view showing the process of forming fine irregularities by laser processing to obtain the metal ornament of the present invention, Fig. 2 is a cross-sectional view of a metal plate on which fine irregularities have been formed, and Fig. 3 is the obtained result. It is a sectional view of the above-mentioned metal ornament. B1. Bz...Laser interference light, G...Precious metal thin film, M2...Metal plate made of stainless steel or Ni-Cr alloy, v, Uz...Minute unevenness.

Claims (2)

[Claims] (1) Fine irregularities corresponding to the intensity distribution of interference fringes of laser light are formed on the surface of a metal made of stainless steel or Ni-Cr alloy, and a noble metal coating is applied to the surface on which these fine irregularities are formed. Iridescent metal ornaments made of a thin layer of paint. (2) Claim (1) wherein the noble metal coating is a thin film of 1 μm or less in thickness made of a metal selected from gold, silver, and platinum.
Iridescent metal ornaments as described.