JPH0780681A - Method for joining noble metal to each other - Google Patents

Abstract

PURPOSE:To join noble metals, such as gold, while preventing the degradation in the purity of the noble metals by the joining at the time of producing ornaments by properly joining the noble metals. CONSTITUTION:A joining agent consisting essentially of a boron compd. is applied to the joining parts of the noble metals, such as gold, and after the joining agent is property dried, the points not requiring joining are coated with a joining preventive agent consisting of talc, etc., and the entire part is heated to a proper temp. in the method for joining the noble metals to each other at the time of forming the ornaments by properly joining the noble metals to each other. As a result, the compd. of the noble metals and boron is formed on the surfaces of the noble metals in the parts coated with the joining agent and the melting temp. of the noble metals of only these parts is lowered and the noble metals of only the joining parts are method with each other and joined even if the other parts are still at the temp. at which the metals do not melt.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joining method for joining precious metals such that gold and the like are appropriately joined together to form a decorative article while preventing the precious metal purity from decreasing due to the joining.

[0002]

2. Description of the Related Art When forming a decorative article such as a jewelry precious metal chain using precious metals such as gold, there are many places where precious metals are bonded to each other.

An example is a ball chain,
Usually, this ball chain is a ball in which part of the periphery is connected as a hollow sphere by curving a plate material to form a tubular body and cutting the tubular body appropriately to narrow both ends. A large number of forming materials are molded, and at this time, a series of ball chains are formed by arranging connecting rods between the ball forming materials, but if the seams are not bonded, pull them with a strong force. If this happens, the seam will open, and the connecting rod will come off, causing the chain to break.

For this reason, conventionally, a bar material having a carat lower than that of a precious metal as a base material is used to bond the bonding points by sticking. Moreover, in order to improve the flow, the filler also contains harmful substances such as zinc and cadmium.

As a specific example, as a general staking method, first, a sapwood is made into a powder, and the powder, castor oil and ligroin are mixed, and, for example, a chain as an ornamental product is contained therein. Immersion, leaving the filler only in the joint part, dropping the filler of the other part, and then putting it in a heating furnace or passing through the furnace, or heating with a torch,
The gluing is done by melting and solidifying the timber.

[0006]

However, such a gluing method has the following problems.

[0007] That is, the first is that, as a filler, a filler having a carat lower than the precious metal of the base material is used, and the purity of the precious metal of the base material is reduced by the amount of the filler, so that The point is that the quality of precious metals is degraded.

The second problem is that the bark contains harmful substances such as zinc and cadmium in order to improve the flow of the bark, which adversely affects the working environment of the worker.

In view of the above-mentioned problems and the like, the present invention prevents the deterioration of the purity of the precious metal due to the joining when joining the precious metal such as gold to form a decorative article, and is harmful. It was created with the goal of improving the working environment without using substances.

[0010]

The present invention relates to a method of joining precious metals such as gold when joining precious metals such as gold to form a decorative article. After that, after drying this bonding agent appropriately, the unnecessary portions of the bonding are covered with a bonding inhibitor such as talc, and the whole is heated at an appropriate temperature to remove the precious metals only at the bonding portion. By melting and joining,
This is to solve the above-mentioned problems.

[0011]

The method for adhering noble metals to each other according to the present invention basically utilizes the effect of significantly lowering the melting temperature of the noble metal itself by forming an alloy of the boron element with the noble metal, particularly gold. There, as a bonding agent, a material mainly containing trimetho group borane which is a boron-based compound, specifically, trimetho group borane, and a small amount of pine resin as a ratio,
Since a material containing castor oil and borax is used, by applying the bonding agent to the joints between the precious metals, the precious metal in the joints becomes an alloy with boron when heated, and the melting temperature drops significantly. .

Therefore, if the noble metals in other parts are heated at a temperature at which they do not melt, the noble metals in the bonding parts are melted and welded together because the melting temperature is lowered.

At this time, the bonding agent is applied only to the portion to be bonded by covering the unnecessary bonding portion with an adhesion preventive agent such as talc, and only that portion becomes an alloy of boron and the noble metal. It melts at a low temperature and is joined as described above.

[0014]

The following is a description of an embodiment of the present invention.

That is, the present invention is a method for joining gold to each other when precious metals, mainly gold, are appropriately joined to form a decorative article.

The basis is the bonding agent, which is a trimetho group borane as a boron compound, which is represented by the chemical formula (CH ₃ O).
_{3 The} main component is B.

Specifically, this bonding agent has a pure boron component concentration of 0.01% in the trimet group-based borane bonding agent.
Quantities of more than or equal to 1% or more of the ingredients in the pine resin binder Castor oil 1% or more of the ingredients of the binder borax (surfactant) 4 types of materials with 1% or more of the ingredients in the binder Are mixed in this proportion to form.

A chain of 18 gold material (Au: 75%, Cu: 12.5%, Ag: 12.5%) as a decorative article is dipped into the bonding agent thus formed, and the bonding agent is applied, and then the bonding agent is applied. The bonding agent is dried for about 10 minutes, and then talc (a powder of talc is used as a bonding inhibitor) is applied to areas where adhesion is not required to drop and cover the bonding agent, and the chain is constructed. By joining talc between the respective members, the chain is passed through the belt furnace 1 as shown in FIG. 1 to heat the entire chain at an appropriate temperature for joining. is there.

Here, the structure of the belt furnace 1 is roughly as shown in FIG.

That is, the electric heat source 2 and the cracking furnace 3 are continuously arranged in parallel, and ammonia is decomposed and burned in the cracking furnace 3 to create an atmosphere. Then, a belt conveyor 4 made of an endless belt is passed from the electric heat source 2 through the electric heat source 2 and the decomposition furnace 3, and a chain is placed on the belt conveyor 4 to heat the belt conveyor 4. .

Here, the furnace temperature is about 890 ° C.,
The passing time in the furnace, that is, the heating time is about 3 minutes.

Then, the melting temperature of gold is usually 1063 ° C.
Therefore, the parts other than the joint part in the chain do not melt, but at the joint part, boron and boron of the trimetho group borane in the above-mentioned bonding agent form an alloy, and the melting temperature is remarkably lowered. Even at the temperature of about 890 ° C, it melts sufficiently and can be joined in a welded state. Therefore, only the necessary portions are joined, and the other portions are not joined because they are protected by talc and the gold itself does not melt.

Here, there are various chains such as Kihei chain, adzuki chain, Venetian chain, etc. as the ornaments, and the respective joining portions are joined by the above-mentioned joining method. In the case of the embodiment, It is used for joining the joining portions during molding of the ball chain 11 as shown in FIG.

Specifically, the ball chain 11 is
A large number of two half-split hollow spheres in which a part of their peripheral edges are connected to each other are formed as the ball-forming material 12, and a connecting rod member 13 is arranged between the ball-forming materials 12 to form a half-split hollow. The spheres are bent and bent in a series so as to form a palm, and the ball-forming material 12 and the connecting rod 13 are not joined to each other, so that they are protected by the talc. As a result, in the conventional case, the seam is not adhered, so if you pull it with a strong force, the seam will open, and the connecting rod will come off and the chain will break, but In addition to solving this problem, it has an important effect of preventing the deterioration of the purity of the precious metal due to the joining.

Needless to say, the present invention can be applied to other noble metal ornaments or joining other noble metals.

Needless to say, the present invention is not limited to the bonding agent of the above-mentioned embodiment, heating conditions, or the like.

[0027]

According to the present invention configured as described above,
Basically, the boron element is used as an alloy with a noble metal, particularly gold, to significantly lower the melting temperature of the noble metal itself, and as a bonding agent, a boron-based compound such as trimetho group borane is used. Since a material containing as a main component, specifically, a trimetho group borane with a small amount of pine tar, castor oil, and borax is used as a proportion, the bonding agent is applied to the joining portion of precious metals. As a result, when heated, the noble metal at the joint becomes an alloy with boron, and the melting temperature drops significantly.

Therefore, if the noble metals in other parts are heated at a temperature at which they do not melt, the noble metals in the bonded parts will be melted and welded together because the melting temperatures have decreased.

At this time, the unnecessary bonding portion is coated with an adhesion preventive agent such as talc to apply the bonding agent only to the portion to be bonded, and only that portion becomes an alloy of boron and the noble metal. It melts at a low temperature and is joined as described above.

Therefore, when a precious metal such as gold is appropriately joined to form a decorative article, as in the case of the conventional gluing, a mortar material having a carat lower than the precious metal is used. It is possible to solve the problem that the purity of the precious metal of the base material is lowered, and to prevent the precious metal purity from being lowered due to the joining by melting and joining the precious metals only at the joining portion,
The working environment can be improved without using harmful substances, and the working process is extremely simple, so that various effects can be obtained such that anyone can join without requiring skill.

[Brief description of drawings]

FIG. 1 is a schematic view of a belt furnace used in the present invention.

FIG. 2 is an enlarged sectional view of a ball chain as a decorative item.

[Explanation of symbols]

1 Belt Furnace 2 Electric Heat Source 3 Decomposition Furnace 4 Belt Conveyor 11 Ball Chain 12 Ball Forming Material 13 Connecting Rod

Claims (1)

[Claims] 1. A method of joining precious metals such as gold to form a decorative article by appropriately joining precious metals such that a joining agent containing a boron compound as a main component is applied to the joining portion, and then the joining is performed. After the agent is dried appropriately, the unnecessary joints are covered with a joining inhibitor such as talc, and the whole is heated at an appropriate temperature to melt and join the precious metals only in the joined portion. How to join precious metals to each other.