JPS6075572A - Manufacture of ornamental multicolor gold alloy - Google Patents

Abstract

PURPOSE:To manufacture an ornamental multicolor gold alloy which is greenish gold or pinkish gold by adhering silver or copper, etc. on gold or a gold alloy in an optional pattern, and treating said alloy in a nonoxidizing atmosphere with thermal diffusion. CONSTITUTION:An adhered layer of silver or copper or silver and copper is formed on the surface of pure gold such as 24K, 18K, and 14K or a gold alloy in an optional pattern with electrolytic plating, electroless plating, vacuum deposition, spattering, ion plating, flame spraying, etc. by using a common plating resist, a masking agent, or a photoresist. The obtained body is heated in a nonoxidizing atmosphere at 300-700 deg.C, and a golden ornamental pattern which is greenish gold and pinkish gold other than original gold of the gold itself is formed with good adhesion.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a decorative multicolored gold alloy that exhibits not only the gold color of conventional gold or gold alloys, but also greenish-gold and pinkish-gold colors.

Gold alloys with various color tones have been produced in the past, but the method of combining these alloys was limited to sandwich structures or recessed structures, so large and linear patterns could not be obtained, making it difficult to create decorative designs. The value was low. There is also a gold-silver, gold-bronze binary metal y-p liquid, but considering the value of gold, it does not seem appropriate to plate gold balls. Currently existing binary gold-silver and gold-copper plating solutions have poor stability, and binary gold-copper plating solutions are particularly bad. Therefore, it is difficult to put it into practical use through mass production. Furthermore, the existing plating solution (gold alloy coating) is not satisfactory in terms of corrosion resistance, and there are many examples of no discoloration or rusting.Therefore, it is necessary to establish a manufacturing method for decorative multicolored gold alloys that solves this problem. It was wanted.

Therefore, the object of the present invention is to freely form an adhesion layer of #I or copper or silver and copper on a gold alloy using a resist in an arbitrary pattern such as a decorative pattern, and then heat it. Through diffusion treatment, in addition to the original gold color, greenish gold and pinkish gold can be expressed in a decorative pattern, and the surface diffusion layer creates an adhesion that cannot be obtained with conventional makeup. The aim is to establish a method that is excellent in both durability and corrosion resistance.This method is used for making decorative items, especially watches, glasses, etc.
For example, we offer a variety of VC colors such as watch sides, eyeglass frames, lights, etc. to expand the degree of freedom in design.

In order to achieve the above object, the gist of the present invention is to provide an adhesion layer of silver or copper in an arbitrary pattern on gold or gold alloy, and to diffuse this on the surface. By this method, a decorative multicolored gold alloy was obtained that had adhesion and corrosion resistance that could not be obtained by conventional plating.

The manufacturing method of the present invention will be briefly explained below.

First, the base gold layer is made of pure gold or gold alloy such as 24, 18, 14, etc. In order to obtain an adhesion layer of silver or copper or silver and copper in any pattern on this surface, using a usual plating resist, masking agent or photoresist, electrolytic plating, electroless plating, vacuum S-deposition, sputtering, etc. The adhesion layer can be closely bonded by ion plate tinkering, thermal spraying, etc. and then diffused by heat treatment.The appropriate thickness of the adhesion layer is 1 to 8μ.If it is less than 1L, the diffusion layer is too thin and is not practical.8μ The above is unsuitable because the undiffused layer is thick and surface polishing is required.The diffusion temperature is 30°C.
If it is below 0°C, the diffusion rate will change too slowly and the holding time will be long, so it is not practical.If it is above 7(]O'C, the entire surface will become rough and the aesthetic appearance will be spoiled. Holding time Vi
The longer the time, which affects the i-plane gold concentration, the higher the surface gold concentration. This changes the corrosion resistance and color tone, so it can be selected arbitrarily. The atmosphere is non-oxidizing, such as inert gas, vacuum, hot isostatic pressure, etc. The layer obtained by this method has excellent adhesion (no problems).

The present invention will be described in detail below with reference to Examples.

Example 1 First, a fine decorative pattern was applied to the gold case No. 18 using Nazar Screen Process Inp/16205F as Turf-1-resist, and silver plating was applied to a thickness of 3μ.
Furthermore, after peeling off the resist, a resist was applied again in the same manner, and copper plating was performed to a thickness of 3 μm. This was subjected to a diffusion treatment in a nitrogen atmosphere at 500° C. for 4 hours.

As a result, 86 diffusion layers were confirmed on each surface using an X-ray microarray analyzer. The color changed from silver to gold-silver alloy, giving it a greenish-gold color, and from copper to gold-copper alloy, giving it a pinkish-gold color. In other words, it's golden.

This resulted in the creation of a glossy fine pattern in three colors: green and pink. This case is made of artificial sweat (composition: salt 9.9
g/l, sucrose 0.22 g/l, 1.
7.%.

Sodium sulfide o, a g/l, ammonia water 0.
A corrosion resistance test was conducted by half-immersing the sample in 18 cc/1 lactic acid (1.10 CC/l) at 40°C for a long period of time. As a result, after 48 hours it was fixed (no change was observed, gold alloy 79
It exhibits corrosion resistance equal to or better than that of gold, and its adhesion through diffusion is incomparable to plating.

Example 2 In the same manner as in Example 1, silver and copper plating with a thickness of 5 μm was applied, respectively, and a diffusion treatment was performed in a nitrogen atmosphere at 650° C. for a holding time. As a result, a diffusion layer of approximately 10 μm in thickness was confirmed in each surface layer, and one color tone was slightly lighter than that of Example 1. This case was subjected to the same corrosion resistance test as in Example 15. As a result, no corrosion occurred after 48 hours, and the surface condition was good.

This is because the diffusion progressed more than in Example 1, and the gold density on the surface increased.

Example 3 A gold alloy layer (22K) of 5 μm was formed on the surface of a brass case normally used for watches by plating, and then silver and copper plating of 3 μm each were applied using the method of Example 1, and then the plate was plated in a nitrogen atmosphere. Diffusion treatment was performed at 400°C for 4 hours.

According to 9, diffusion layers of silver and copper were confirmed in 7,000 layers of the surface layer, and diffusion into the brass, which is the base material for gold plating, was also observed, proving that the base material and the plating were integrated.9. In the corrosion resistance test, no change in surface condition was observed after 48 and a half hours of immersion in artificial sweat. In this way, it is easily possible to apply not only gold alloys such as No. 18 but also gold alloy coatings on the surface, such as electrolytic plating, electroless plating, and foils.

6- Example 4 After applying a masking agent in a decorative pattern to the gold case in 18, a 1.2μ silver layer was formed by vacuum deposition, and this was thermally diffused in a vacuum furnace at 600°C for 6 hours. I did it. As a result, a gold-silver alloy layer is formed on the surface, and there is no problem of adhesion as in the other embodiments, and the problem of vacuum evaporation, which normally has poor adhesion, can be solved by this method. Regarding corrosion resistance, tests similar to those in other examples were conducted and no problems were found.

The present invention allows fine decorative patterns to be freely expressed in green or pink on gold or gold alloy, and its surface layer has adhesion that cannot be obtained with conventional plating, etc., and also has good corrosion resistance, such as decorative items. The objective is to create a new decorative multicolored gold alloy that provides color variety to watch parts, eyeglass frames, lighters, etc., and expands the degree of freedom in design.

In terms of applications, the metal to be diffused is not limited to silver or copper, but as long as it is a metal that can be diffused into gold, it is possible to easily change the color tone by providing a diffusion layer on the entire surface using this method. Furthermore, it can be easily assumed that the base material is a metal such as silver or copper, and a gold film is formed on the surface and then subjected to a diffusion treatment, and it is clear that some variations are included in the present invention.

that's all Applicant: Suwa Seikosha Co., Ltd. Agent Patent Attorney Mogami

Claims (1)

[Claims] Silver or copper or silver and copper are adhered to gold or gold alloy in any pattern, and in a non-oxidizing atmosphere, 300 to 700
A method for producing a multicolored gold alloy for decoration, characterized in that a gold-silver alloy layer is formed in an arbitrary pattern on the surface by subjecting it to a heat treatment of "C" to diffuse the gold-silver alloy layer on the surface.