JPH0686708A - Production of hollow ornaments - Google Patents

Abstract

PURPOSE:To provide the process for production of the hollow ornamental parts which have no clearances in joint parts, are free from the infiltration of moisture and the discoloration of brazing filler metals and have an excellent ornamental effect. CONSTITUTION:The surface of a conductive base material 2 penetrated with a pipe 1 in a desired position is electroplated to form an electroplating layer 6 of a noble metal or noble metal alloy. This conductive base material 2 is then melted and is removed from a lead wire hole 7 to form the outside shape of the hollow noble metal ornaments from the electroplating layer, by which the ornaments are produced. Since the brazing filler metal 3 is not exposed, the discoloration and softening of the brazing filler metal 3 do not arise. Since the pipe penetrates the ornaments and no clearances exist, and the advance of the moisture into the ornaments does not arise. The ornamental parts having an arbitrary shape and arbitrary thickness are produced by adjusting the shape of the conductive base material and the energization quantity at the time of electroplating.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a hollow precious metal decorative part used for connecting necklaces, earrings, bracelets, anklets, watch bands and the like.

[0002]

[Prior art and its problems] Conventionally, hollow precious metal ornaments have been manufactured by electroforming, and pipes and pins are used to connect the precious metal ornaments such as necklaces and earrings. However, if the decorative part and the pipe are not joined, water or the like will enter the part through the gap and it will be extremely difficult to remove it. There was a flaw. Also, in order to solve the drawback, brazing of parts and pipes is performed, but since the brazing material used is a noble metal alloy having a relatively low content of noble metal, it is easily discolored and brazed. There is a drawback that the periphery is easily annealed and softened, and that a complicated shape requires labor for brazing work.

[0003]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks of the prior art. A hollow precious metal decorative component used by connecting with a pin or the like and a pipe are integrated to form a decorative component without a gap. It is intended to provide a method for manufacturing.

[0004]

DISCLOSURE OF THE INVENTION The present invention is a method for producing a hollow noble metal decorative part used by joining together, in which a surface of a conductive base material penetrates a noble metal or noble metal alloy pipe at a desired position. Hollow decoration characterized by performing electroplating to form a noble metal or noble metal alloy electroplating layer, and then melting the conductive base material to form a hollow outer shape of the noble metal decorative component by the electroplating layer. It is a method of manufacturing a component.

The details of the present invention will be described below. In order to manufacture the decorative component by the method of the present invention, first, a conductive base material having the same shape as the required decorative component is prepared. The material of this conductive base material is preferably silver, copper and its alloys or solders, and these materials are not only materials that are easy to electroplate precious metals or precious metal alloys such as platinum and gold, but also cast and This is because it is extremely easy to process and is suitable for producing a hollow precious metal decorative component by electroplating a precious metal or the like and then easily dissolving it in an acid such as nitric acid.

The method for producing the conductive base material is not particularly limited. For example, a solid prototype of a decorative part having a desired shape is designed, a hollow rubber mold is produced from the prototype, and wax is poured into the rubber mold. A wax pattern is produced, and after the wax pattern is solidified with gypsum, the wax pattern is melted to form a gypsum mold, and a molten metal such as silver or copper, which is a material of the conductive base material, is poured into the gypsum mold and then It can be prepared by cooling. And in the present invention, the conductive base material is used by piercing the pipe at a desired position, but the pipe may be formed by passing the pipe through the conductive base material formed into a predetermined shape, but is preferable. Is a step of setting the pipe at a required position of a mold for molding the conductive base material, pouring the molten metal for the conductive base material into the mold, and molding the pipe to make a conductive base material having a hollow pipe. It is also desirable to simplify. That is, the pipe is set at a desired position of the rubber mold before completing the wax pattern in the process of producing the conductive base material described above, and is integrated with the wax pattern formed by injecting wax, or the wax pattern is formed. After molding the pipe into the desired position of the pattern and covering with gypsum to harden it, the wax is dissolved and removed by heating, and the pipe is a material of the conductive base material in a gypsum mold fixed. It is possible to produce a conductive base material in which a molten metal is poured and cooled to form a pipe. The positional relationship between the conductive base material and the pipe may be determined according to the shape of the desired decorative component, and usually the mutual relationship is such that both ends of the pipe slightly project from the conductive base material. Then, both ends of the pipe are closed with a resin or the like so that the plating liquid of the electroplating that is subsequently performed does not flow in. If the positional relationship between the conductive base material and the pipe may change during the next electroplating, it is desirable to fix the two by brazing or the like.

Then, a current-carrying lead wire is connected to an arbitrary position on the surface of the conductive base material, the conductive base material and the counter electrode are immersed in an electroplating bath containing a precious metal such as gold or platinum, and An electroplating layer of a noble metal or a noble metal alloy is formed on the surfaces of the conductive base material and the pipe by energizing the conductive base material and the counter electrode. Even if the above-mentioned brazing is not performed, the electroconductive base material and the pipe are securely integrated by the electroplating layer formed on the surface, and the pipe can be fixed accurately without displacement or deformation. Moreover, even when brazing is performed in advance, since the braze is covered with the electroplating layer and is not exposed, the drawbacks of the prior art such as discoloration or softening are eliminated. Since the electroplating is electroplating, even if the electroconductive base material has a complicated shape having, for example, a large number of irregularities, the electrolytic solution in the electroplating bath uniformly contacts the electroconductive base material and the pipe surface to form a uniform electroplating layer. Can be formed, and the electroplating layer can be made to have an arbitrary thickness by adjusting the amount of electric current.

Then, the electroconductive base material and the like electroplated to the required thickness are taken out from the electroplating apparatus, and the lead wire is removed. In this state, when the conductive base material or the like is immersed in a solution such as nitric acid that dissolves the conductive base material, the conductivity of the exposed portion where the electroplating layer is not formed because the lead wire is connected. The base material comes into contact with the nitric acid or the like to gradually dissolve toward the inside, and finally the entire conductive base material can be dissolved and removed. It is desirable to completely dissolve and remove the conductive base material. Whether the conductive base material is completely dissolved is determined by immersing in a dilute nitric acid solution for 20 to 20
After heating for 30 minutes, it can be confirmed by analyzing the metal ions of the conductive base material in the dilute nitric acid solution. As a result, a hollow decorative component with a pipe having the same shape as the conductive base material and having a hole in the lead wire connecting portion is produced. Next, this decorative part is thoroughly washed with hot pure water or the like to remove impurities on the surface and inside of the decorative part, dried with warm air, and then heated in an electric furnace at 400 ° C.
Heat to ~ 600 ° C to completely evaporate and remove water. If the heating temperature is excessively increased, the decorative component may be deformed or cracked, which is not preferable. Then, in order to block the above-mentioned holes, a sealed hollow precious metal decorative component having a desired shape can be obtained by brazing with a precious metal such as a precious metal, preferably the same material as the electroplated layer. A plurality of the ornamental parts can be connected by an appropriate means to form a precious metal ornament such as a necklace, an earring, a bracelet, an anklet and a watch band.

Next, the procedure for manufacturing a hollow decorative component made of a noble metal by the method of the present invention will be illustrated with reference to the accompanying drawings, but the present invention is not limited to the illustrated examples. Figure 1
4 to 4 are vertical cross-sectional views illustrating a series of steps of manufacturing a hollow decorative component by coating a noble metal on a spherical base material by electroplating. FIG. 1 shows a spherical conductive base material 2 made of silver, copper, or the like, in which a pipe 1 with both ends slightly protruding is pierced, and a braze 3 is brazed to a contact portion between the pipe 1 and the conductive base material 2. Then, the two are fixed, the lead wire 4 is connected to the surface of the conductive base material 2, and the resin 5 is filled into both ends of the pipe 1 to obtain the conductive base material for electroplating shown in FIG.

Next, the conductive base material 2 with the pipe 1 shown in FIG.
The surface of the conductive base material 2 and the exposed surface of the pipe 1 are coated with a noble metal electroplating layer 6 by immersing in an electroplating bath in which a compound of a noble metal such as gold or platinum is dissolved.
When the lead wire 4 is taken out from the electroplating bath after the energization is stopped and the lead wire 4 is removed, the electroplated conductive base material 2 in which the electroplating layer 6 is not formed only in the lead wire hole 7 as shown in FIG. Is obtained. When the electroconductive base material 2 having the electroplated layer 6 is dipped in a dilute nitric acid solution or the like, the electroconductive base material 2 is contacted and dissolved with the dilute nitric acid solution through the holes 7, and finally the electroconductive base material 2 is dissolved. After the material 2 is completely melted, the hole 7 is brazed with the noble metal 8 and the resin 5 filled at both ends of the pipe 1 is removed, so that a decorative component having a desired shape shown in FIG. 4 can be obtained.

Next, examples of the method of the present invention will be described, but the examples do not limit the present invention.

Example 1 A sphere having a diameter of 10 mm made of a base material made of silver was made to penetrate a pipe made of 18-karat gold and having an outer diameter of 1 mm and an inner diameter of 0.8 mm and fixed with silver brazing, and the sphere was protruded by 3 mm on both sides,
Block the holes on both sides of the pipe with thermosetting resin,
mm of copper lead wire was brazed and gold was electroplated to a thickness of 100 microns. The gold plating bath uses a thick plating bath (manufactured by Nippon Electroplating Engineers: Art Form 18) and the plating conditions are 70 ° C.
It was carried out at 1.5 A / dm ² for 3 hours.

Then, the lead wire is removed and diluted nitric acid (1:
2) Put the gold-plated spheres in the solution, heat to 60 ° C for 4 hours to dissolve the base material silver, wash with pure water, and then put in a new dilute nitric acid (1: 1.5) solution. It was treated at 60 ° C for 20 minutes, and when silver concentration in the dilute nitric acid solution was measured by atomic absorption spectrometry, no silver was detected, so after thoroughly washing with hot pure water at 80 ° C, dried with warm air with a dryer, Water was completely removed by heating in an electric furnace at 400 ° C for 15 minutes. Next, the hole where the lead wire was removed was brazed and closed with gold brazing using a gold foil having a thickness of 100 μm, and buffing was performed to obtain a decorative part with a hollow spherical pipe protruding. The gold hollow spheres obtained by the above method were connected by a gold strand having a tip of white zirconia stones, and a stopper was attached to form an earring. When the produced earrings were immersed in water for 1 hour and taken out, water was contained in the pipe, but water was not contained in the hollow ball portion.

[0013]

[Embodiment 2] A V-shaped piece made of a copper base material is penetrated with a pipe having an outer diameter of 1 mm and an inner diameter of 0.8 mm of 90% by weight of platinum and 10% by weight of palladium at three portions of the tip portion and the open portion of V. It was fixed with silver solder in a state of protruding by 1 mm on each side. The holes at both ends of the pipe were closed with a heat-resistant polyvinyl chloride rod, a 2 mm copper lead wire was brazed to the back surface of the V-shaped tip, and platinum was electroplated to a thickness of 80 μm. As the platinum plating bath, a platinum thick plating bath (manufactured by Nippon Electroplating Engineers: Platinate 100) was used, and the plating conditions were 90 ° C. and 2.5 A / dm ² for 3.5 hours.

Then, the lead wire was removed, the platinum-plated piece was placed in a dilute nitric acid (1: 1) solution, the temperature was raised to 60 ° C., and the treatment was performed for 3 hours to dissolve the copper of the base material and then pure water. It was washed and then placed in a new dilute nitric acid (2: 1) solution and treated at 60 ° C for 20 minutes. The copper concentration in the dilute nitric acid solution was measured by atomic absorption spectrometry. After thoroughly washing with pure water, dry with warm air with a dryer and
Water was completely removed by heating in an electric furnace at 0 ° C for 15 minutes. Next, the hole where the lead wire was removed was brazed with platinum brazing using a platinum foil with a thickness of 80 microns, buffed, and a decorative part with a hollow V-shaped pipe with three protruding parts Obtained. Fifteen of these decorative parts were connected by pins to form a watch chain. When the manufactured watch chain was soaked in water for 1 hour and taken out, water was in the pipe, but water was not in the hollow V-shaped portion.

[0015]

[Prior art example] A base material made of silver is brazed with two 3 mm pipes on opposite sides of a sphere having a diameter of 10 mm, and the side surface of the sphere is 1.5
mm mm copper leads were brazed and gold was electroplated to a thickness of 100 microns. The same gold plating bath as in Example 1 was used, the plating conditions were the same as in Example 1, and plating was performed for 3 hours. Then, the lead wire was removed, and after dilute nitric acid treatment, pure water washing and treatment with fresh dilute nitric acid (1: 1.5) under the same conditions as in Example 1, the silver concentration in the dilute nitric acid solution was determined by atomic absorption spectrometry. Since silver was not detected in the measurement, it was thoroughly washed with hot pure water at 80 ° C., dried with warm air in a dryer, and heated in an electric furnace at 400 ° C. for 15 minutes to completely remove water.

Next, the hole of the portion where the lead wire is removed is brazed and closed with a gold braze using a gold foil having a thickness of 100 μm, and buffing is performed to obtain a decorative part with a hollow spherical pipe protruding. However, the center of the pipe was misaligned. Three gold hollow spheres obtained by the above method were connected by a gold stranded wire having a tip of white zircon stone, and a stopper was attached to form an earring. When the manufactured earrings were immersed in water for 1 hour and taken out, it was difficult to remove the water because the hollow spheres contained water from inside the pipe.

[0017]

[Example 3] When a gold base material was pierced into a silver base material similar to that of Example 1, raw rubber was vulcanized using a prototype to prepare a rubber mold, and the center of the mold was prepared. Set the pipe, inject and solidify the wax to complete the wax pattern, then fix by covering with gypsum, heating at 800 ° C to melt and evaporate the wax and fix the gold pipe in the gypsum mold, Then, a molten metal of silver was poured and cooled to obtain a silver base material having a gold pipe pierced. In addition, after fixing the gold pipe above the center of the one after completion of the wax pattern, fix it with gypsum and heat it at 800 ° C to dissolve and evaporate the wax and fix the gold pipe in the gypsum mold. Then, a molten metal of silver was poured and cooled to obtain a silver base material having a gold pipe pierced. Using the base material obtained by the above method, a plating operation was performed in the same manner as in Example 1 to obtain a hollow spherical tube obtained by dissolving the base material in nitric acid. Almost the same as that obtained was obtained.

[0018]

INDUSTRIAL APPLICABILITY According to the present invention, in a method for producing a hollow precious metal decorative component to be used by joining together, electroplating is performed on a surface of a conductive base material that penetrates a pipe of a precious metal or a precious metal alloy at a desired position. A method for producing a hollow decorative component, characterized in that an electroplated layer of a noble metal or a noble metal alloy is formed, and then the conductive base material is melted to form the hollow precious metal decorative component by the electroplated layer. 1)
Is. That is, in the present invention, since the surfaces of the pipe and the conductive base material of the conductive base material in which the pipe is penetrated are coated with an electroplating layer such as a noble metal, the pipe and the conductive base material are electrically conductive. Even if both are fixed by the plating layer and not fixed by brazing before electroplating, both are securely fixed by this electroplating, and the pipe and conductive base material are fixed by brazing before electroplating. However, since the electroplating layer is present, discoloration or softening of the brazing material does not occur, and the drawbacks of the prior art are eliminated. Then, the conductive base material is melted by bringing it into contact with dilute nitric acid or the like through the lead wire hole after electroplating, and then the hole is brazed and closed with a predetermined precious metal or the like to form a closed hollow predetermined shape. It is possible to obtain a decorative part with a pipe having In the decorative part obtained by the method of the present invention, water does not enter into the decorative part because the pipe penetrates the cave and there is no gap, and even if the decorative part is connected and used as a necklace, etc. No more soiling your clothes.

Furthermore, by adjusting the shape of the conductive base material and the amount of electricity applied during electroplating, it becomes possible to easily and in large quantity manufacture decorative parts of arbitrary shapes and thicknesses. The electroplating layer is preferably formed of a noble metal such as gold or platinum (claim 2), and the surface of the decorative component can be decorated with the noble luster of the noble metal. Further, it is desirable that the pipe is set before or after completion of a wax pattern as a mold of the conductive base material to accurately determine the position with respect to the conductive base material (Claim 3). You can set the cave position.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view illustrating a conductive base material in which a pipe is hollowed during a series of steps of the method of the present invention.

FIG. 2 is a schematic vertical cross-sectional view illustrating a state where lead wires are similarly connected to the conductive base material.

FIG. 3 is a schematic vertical cross-sectional view illustrating a state in which an electroplating layer is formed on a conductive base material.

FIG. 4 is a schematic vertical cross-sectional view illustrating a decorative component with a pipe in which a conductive base material is melted and lead wire holes are brazed and closed.

[Explanation of symbols]

1 ... Pipe 2 ... Conductive base material 3 ... Brazing material 4 ... Lead wire 5 ... Resin 6 ... Electroplating layer 7 ... Lead wire hole 8 ... Noble metal

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[Procedure amendment]

[Submission date] August 19, 1993

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Figure 1]

[Fig. 2]

[Figure 3]

[Figure 4]

Claims (3)

[Claims] 1. A method for producing a hollow noble metal decorative component used by joining together, wherein the surface of a conductive base material that penetrates a noble metal or noble metal alloy pipe at a desired position is electroplated to form a noble metal or noble metal alloy. Forming an electroplated layer, and then dissolving the conductive base material to form the hollow external shape of the precious metal decorative component by the electroplated layer. 2. The method according to claim 1, wherein the noble metal or noble metal alloy for electroplating is platinum, gold or an alloy thereof. 3. The method according to claim 1, wherein the conductive base material that penetrates the pipe is set before or after the completion of the wax pattern that forms the mold of the conductive base material.