JPS61205687A - Manufacture of ornamental products - 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] [Technical Field of the Invention] The present invention relates to a method for manufacturing a decorative article using a silicon nitride material as a base material, and more specifically, the present invention relates to a method for manufacturing a decorative article using a silicon nitride material as a base material, and more specifically, the base material is silicon nitride material and a precious metal pattern is arranged on the surface of the base material. The present invention relates to a method for manufacturing decorative articles.

[Technical background of the invention and its problems] High-grade ornaments are generally either precious stones or precious metals. This is because these things have scarcity value and at the same time
This is because it stimulates the human sense of beauty in terms of color tone, shine, etc. Especially diamonds.

It is no exaggeration to say that the brilliance of precious stones, such as sapphires and rubies, determines their commercial value.

What absolutely determines the brilliance of a precious stone is the hardness of the precious stone, as well as the skill of polishing the stone.

In particular, regarding the hardness of precious stones, if the polishing techniques are at the same level, the higher the hardness of the precious stones, the more beautiful the polished finish will be. Moreover, even if some external trauma occurs during use, there is little risk of damage and deterioration in value.

To date, most precious stones have been produced naturally, but recently, due to the development of material synthesis technology, attention has been paid to the amount of precious stones that have been produced artificially.

For example, one of them is silicon nitride material.

This material has a higher hardness than natural alumina materials such as sapphire, ruby, and emerald, making it suitable for use as a decorative item, and its polished surface has a glossy greenish black-gray color that gives it a noble feel. However, since this material is opaque and cannot be used directly as a substitute for precious stones, efforts have been made to use it as a background for ornaments and to combine it with other precious metals to create ornaments. There is.

However, since silicon nitride is a material with high chemical stability, desired noble metals cannot be directly combined on its surface.

[Object of the Invention] The present invention solves the above-mentioned problems when silicon nitride is used as a background base, and provides a method for manufacturing a decorative article in which a precious metal design is integrally formed on the surface of silicon nitride as a base. For the purpose of providing.

[Summary of the Invention J] As a result of extensive research to achieve the above object, the present inventors found that (1) the surface of silicon nitride slightly decomposes into its constituent components, namely silicon and nitrogen, under high-temperature vacuum as described below. ■
They discovered the fact that if a metal or alloy described later is placed here, the separated silicon reacts with this metal or alloy, and the resulting reaction product (alloy) becomes molten and wets the surface of silicon nitride. By utilizing this fact, we have developed the method of the present invention.

That is, the method for manufacturing an ornament of the present invention includes a step of distributing a metal or alloy that easily reacts with silicon in a pattern on the surface of a silicon nitride material: heat treatment at a degree of vacuum of 1 x 10 Torr or higher and a temperature of 1200°C or higher. The method is characterized by comprising a step of forming a metallized layer on the patterned portion; and a step of electroplating the metallized layer with a noble metal and then polishing the metallized layer.

The first step in the method of the present invention is to first arrange a metal or alloy that easily reacts with silicon on the surface of a silicon nitride material in a desired pattern, as will be described later.

Such metals or alloys: (1) easily react with silicon under high-temperature vacuum conditions as described below; (2) the melting point of the reaction product (alloy) with silicon is lower than its own melting point before the reaction; and (2) It satisfies the condition of not melting under high-temperature vacuum conditions, which will be described later.

To give a specific example, the metal is nickel.

Iron and cobalt can be mentioned, and examples of alloys include alloys containing 50% or more of the above metals, such as various silicon steels, carbon steels, alloy steels, special steels, Ni-0r alloys, old-A1 alloys, Xl-Ti alloy 1 can be mentioned as a superalloy.

Further, the metal to be applied may be platinum, palladium, or an alloy thereof.

These metals or alloys are available in powder, linear, or foil form.

It may be provided in the form of either a vapor deposited film or a sprayed film.

For example, it is preferable to prepare a paste by dispersing powder in ethyl alcohol or polyvinyl alcohol, and apply this paste to the surface of the silicon nitride material. At this time, if a desired design pattern is drawn by hand or by printing, this pattern will be directly formed as a decorative pattern through subsequent steps.

In the second step, the entire surface of the silicon nitride material obtained in the first step is heat-treated with the metal or alloy in a vacuum furnace, so that the patterned portion is reflected on the metallized layer. It is a process. In this process, first, the surface of silicon nitride is slightly decomposed into silicon and nitrogen. and,
This decomposed silicon reacts with the above metal or alloy to produce a reaction product (alloy) with a lower melting point than the metal or alloy, and this reaction product melts on the surface of silicon nitride and wets the surface. Become. If it cools down.

This becomes a metallized layer, which is formed as a pattern.

The conditions for this treatment are a vacuum degree of I x 10' Torr.
It is necessary that the temperature is 1200° C. or higher.

If either the degree of vacuum or the temperature exceeds the above conditions,
Decomposition of the surface of the silicon nitride material → Reaction of the decomposed silicon with a metal or alloy that easily reacts with silicon → Formation of a reaction product and its melting → The molten reaction product wets the surface of the silicon nitride and a metallized layer is formed. That process does not proceed.

In the third step, a desired amount of, for example, platinum is applied onto the patterned metallized layer formed in the second step.

It is a process in which precious metals such as gold or silver are deposited by electroplating, and then the surface is polished.

The electroplating method is not particularly limited, and a conventional polishing method may be applied.

Note that the metallized layer formed in the second step is formed by a reaction with silicon nitride, so it has strong adhesion to the silicon nitride surface, and is formed in a state where it permeates slightly from the surface to the inside. Therefore, even in the polishing stage of the third step, the metallized layer can be left in place and the polishing process can be carried out.

In this way, it is possible to obtain a novel ornament in which the surface of silicon nitride is used as a background base, and noble metals are arranged therein in a desired pattern.

[Embodiment of the Invention] The surface of a silicon nitride elliptical plate with a major axis of 50 mm, a short axis of 30 m, a thickness of 5 mm, and a thickness of 5 mm was polished to 0.3 S, and carbonyl nickel powder (particle size 1 to 3 u), ? A paste consisting of polyvinyl alcohol was applied with a brush in a pattern. Next, put the whole thing into a vacuum furnace and heat the inside of the furnace to 5 x 104 To
After evacuation to rr, it was heated to 1250°C at a temperature increase rate of 800°C/hr and held at this temperature for 10 minutes.

After cooling, the treated piece was taken out of the furnace and observed, and it was confirmed that about 10 metallized layers were present on the surface of the silicon nitride plate, and that the interface between the two was continuous.

Thereafter, this metallized layer was electroplated with gold using a cyanide bath, and the gold plated surface was separately polished.

The result was an ornament in which gold glittered in bright tones against a shiny black-gray silicon nitride surface.

[Effects of the Invention] As is clear from the above explanation, according to the method of the present invention, silicon nitride, which has extremely high hardness and therefore has excellent polishing efficiency, is combined with a precious metal that gives a different kind of aesthetic sense in an integrated pattern. Since it can be depicted as a pattern, it is possible to obtain ornaments that create an unprecedented noble atmosphere. Moreover, because it is manufactured artificially without using precious stones, which are rare resources, its industrial value is great.

Claims (1)

[Claims] 1. Step of distributing a metal or alloy that easily reacts with silicon in a pattern on the surface of silicon nitride material; degree of vacuum 1×10^
- A decorative article comprising the following steps: forming a metallized layer on the patterned portion by heat treatment at a temperature of 1200° C. or higher at a temperature of 3 Torr or higher; a step of electroplating the metallized layer with a precious metal and then polishing the metallized layer; manufacturing method. 2. The method according to claim 1, wherein the metal or alloy that easily reacts with silicon is platinum, palladium, or an alloy thereof.