JPH0426701A - Manufacture of fine gold ball - Google Patents

Abstract

PURPOSE:To obtain fine gold ball having the fixed particle size and shape with good yield by cutting gold fine wire to make short fine wire, heating this on the way of dropping to make molten ball and then, rapidly cooling. CONSTITUTION:The gold fine wire having the fixed diameter is cut to the fixed length to make the short fine wire 6 having the fixed wt. This short fine wire 6 is uncontinuoulsy dropped from a feeder 11. Below outlet 11B is the feeder, a heating cylinder 12 is set and the short fine wire 6, dropped by gravity becomes molten state with heating. Then, this is made to the molten ball 13 with the gravitation and surface tension. The molten bell 13 is further dropped with the dead wt. and rapidly cooled in water 15, etc., in a vessel 14 to make the fine gold ball 16.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing fine gold spheres having uniform size and shape.

(Prior art) Generally, gas atomization method or water atomization method is known as a method for producing metal powder.A gas jet flow or a water jet flow is applied to the drip stream of molten metal to atomize the molten metal. This is a method of producing metal powder by atomizing and rapidly cooling. Fig. 3 illustrates a method of producing fine gold spheres by this gas atomization method.

Gold is melted in a melting furnace 51, and molten gold 52 at a constant temperature is pooled. This molten gold 52 is dripped from a drip nozzle 53 to form a thread-like drip stream 54.

This drip stream 54 is located within the jet stream of the atomizing nozzle 56 from which the inert gas 55 is jetted. Due to the gas turbulence 57,
The gold drip stream 54 is atomized and becomes fine gold spheres 58 . The fine gold spheres 58 fall into the water 60 of the tank 59 and are rapidly cooled, settling at the bottom of the tank 59. Thereafter, through a sorting process, fine gold spheres of a predetermined particle size are obtained. In addition, in order to make the shape of the fine gold sphere 5B as ball-like as possible,
A high temperature gas may be used as the inert gas 55.

In addition, in order to produce finer gold particles, there is also one in which the two atomizing nozzles 56 are arranged in a downward V-shape, and the dripping stream 54 is located in the center of the V-shape.

[Problem to be solved by the invention]

In the method for producing fine gold spheres using the gas atomization method described in the conventional technology, molten gold is atomized by gas turbulence, so the particle size distribution is wide and the shape is often irregular rather than a ball. Therefore, a sorting step is required to select those having a predetermined particle size and ball shape from among these fine gold spheres. However, there were problems in that it was extremely difficult to sort out the fine gold spheres, including their shape, and the yield was low.

The present invention has been made in view of the above-mentioned problems of the conventional technology, and its purpose is to provide a method for manufacturing fine gold spheres with a constant particle size and shape with a high yield. It is something to do.

[Means to solve the problem]

In order to achieve the above object, the method for manufacturing fine gold balls in the present invention involves cutting a thin gold wire into a certain length to make short thin wires, dropping the short thin wires discontinuously, and dropping the short thin wires while they are falling. It is heated to form a molten ball, then cooled to form a fine gold sphere.

[Function] A short thin gold wire cut into a certain length has a constant weight, and when it is melted into fine gold balls, there is no variation in particle size. The tension creates a uniform ball shape.

〔Example] Examples will be described below with reference to the drawings.

FIG. 1 is a diagram showing the process of manufacturing short thin wires from thin gold wires, and FIG. 2 is a diagram showing the process of making short thin wires into fine gold balls.

First, the process of manufacturing short thin wires from thin gold wires will be explained. In FIG. 1, a thin gold wire 1 is fed from a drum 2 to a feed roller 3. This fine gold wire 1 is sent out to a guide 4 by a constant length by a feed roller 3 which is driven intermittently.

Then, the thin gold wire 1 at the exit of the guide 4 is connected to the feed roller 3.
The wire is canted by a laser cutting machine 5 that operates in conjunction with the laser cutting machine 5, and becomes a short thin wire 6 of a predetermined length. The short wires 6 are collected in a box 7 and sent to the next process. In addition, as a cutting means,
In addition to the laser cutting machine 5, a mechanical cutting machine using a known cutter blade can also be used.

Further, it is also possible to increase cutting efficiency by cutting multiple rows of thin gold wires 1 at the same time.

By the way, the thin gold wire 1 manufactured in the following manner is used. Using electrolytic gold with a total purity of 99.99% by weight or more, this electrolytic gold is melted and cast in a high frequency vacuum melting furnace,
After rolling this ingot, it is drawn into a fine gold wire at room temperature. Further, the final wire diameter of such fine gold wire is not particularly limited, but when attempting to obtain fine gold spheres with a diameter of about 20 to 200 μmφ, the final wire diameter is 10 to 50 μm.
It is preferable to set it to approximately mφ.

To illustrate one example in the present application, when a short thin wire 6 obtained by canting a 25 μmφφ thin gold wire to a length of 300 μm is used, a fine gold sphere with a diameter of 65 μmφ is obtained.

Next, a process of turning the above-mentioned short wire into fine gold balls will be explained. In FIG. 2, a short thin wire 6 is dropped discontinuously by a feeder 11. Here, discontinuously refers to a state in which the short wires 6 are supplied separately with distances in the vertical and horizontal directions, as shown in the figure. Such a feeder 1
] Examples include a vibration feeder having a fixed ultrasonic transmitter 11A. A heating cylinder 12 is disposed below the feeder outlet 1.1B, and the short wire 6 that falls due to gravity is heated to become molten. Then, it becomes a molten ball 13 due to gravity and surface tension. This heating cylinder 12 has a burner 12A on its side, and uses a downward heating swirl flow to heat the short wires 6 while preventing them from coming into contact with each other. In addition,
Instead of the heating tube 12 using the burner 12A, a dielectric heating device filled with inert gas may be used. Then, the molten ball 13 further falls under its own weight, and the water 1 in the container 14
The particles are quickly cooled in the gold sphere 5 and become fine gold spheres 16. Note that the cooling means is not limited to rapid cooling using water 15, but may be based on gas air cooling.

According to the above process, a thin gold wire of a certain thickness is cut into a certain length to form a short thin wire 6 of a certain weight, and the short thin wire 6 is freely falling in pieces and melted to form fine gold spheres.
6, the particle size and shape are uniform, and the yield is greatly improved.

〔Effect of the invention〕

As explained below, the method for manufacturing fine gold balls according to the present invention involves cutting a thin gold wire into a certain length to make short thin wires, dropping the short thin wires discontinuously, and dropping the short thin wires in the middle of falling. This method heats to form a molten ball, and then rapidly cools the molten ball to form fine gold spheres.Since a certain weight is melted to form fine gold spheres, there is no variation in particle size, and there is no discontinuous falling. Since the heating is done midway, a uniform ball shape is formed due to gravity and surface tension. Therefore, fine gold spheres having a uniform ball shape and a constant particle size can be produced with a high yield.

In addition, extremely complicated sorting processes are no longer necessary.

[Brief explanation of drawings]

Part 1 is a diagram showing the process of manufacturing short thin wire from fine gold wire, Figure 2 is a diagram showing the process of turning short thin wire into fine gold spheres, and Figure 3 is a method of manufacturing fine gold spheres using the conventional gas atomization method. , and the explanations of the main symbols in the drawing are as follows. ■...Fine gold wire, 6...Short thin wire, 13...Melted ball, 16...Fine gold ball, 5...
Laser cutting machine (cutting means), 12... heating cylinder (heating means), 15... water (cooling means). Patent applicant: Tac Electric Cable Co., Ltd. Fujitsu Limited Agent: Yoshiyuki Kaji, patent attorney

Claims (1)

[Claims] (1) Cut a thin gold wire to a certain length to make short thin wires, drop the short thin wires discontinuously, heat the short thin wires as they fall to form molten balls, and rapidly cool the molten balls to form fine metals. A method for producing fine gold spheres, characterized by forming them into spheres.