JPS6064289A - Preparation of wristwatch case - Google Patents

Abstract

PURPOSE:To reduce the number of processes while obtaining a plating shell case with good quality, by forming a conductive film to the inner surface of a plastic electroforming matrix mold and applying the electrodeposition of a metal to said conductive film while detaching the formed electroforming shell to apply finish plating thereto, and pushing the plated shell into a plastic replica to perform injection molding using an injection mold. CONSTITUTION:A plastic electroforming matrix mold 4 is fabricated by a plastic molding method and the inner surface of the matrix mold 4 is covered with a conductive film while the electrodeposition of a metal such as Ni, Cu or Au is applied to said film to form an electroforming shell 1. This electroforming shell 1 is detached from the matrix mold and finish plating is applied thereto while the plated shell is pushed into a plastic replica 8. The whole is inserted into an injection mold 9 and a plastic inner middle 2 is formed by injection molding to complete the middle of a clock case. By this method, the number of processes are reduced and a plating shell case with good quality is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a shell case for a wristwatch, the outer surface of which is made of metal and the inner surface made of glass.

Conventional shelled cases have been manufactured by metal shell stamping or brazing, but with this method, the dimensions of the shell and injection cavity shape can be precisely matched during insert injection molding. However, since the shape of the shell is partially deformed by the molding pressure during insert molding, there is a drawback that surface finishing such as abrasive grinding is performed in a subsequent process.

(1) The heat generated by the abrasive grinding process in the post-process creates a minute gap between the shell and the plastic, which deteriorates the adhesion between the shell and the plastic of the inner shell.

(2) In the case of a shell that requires gold plating, the plating solution enters the gap created in (1) and cannot be completely removed afterwards, resulting in poor corrosion resistance.

The present invention has been developed to eliminate the above-mentioned drawbacks, and reduces the number of steps and provides a plated shell case of good quality, and at the same time has a good finished appearance.

This is a manufacturing method for obtaining.

The present invention will be explained in detail below with reference to embodiments shown in the drawings.

Figure 1 shows the watch side manufactured by the method of the present invention. It has a shell and consists of an inner shell 2 made entirely of plastic.

In order to manufacture the above-mentioned watch/1lljl, as shown in Figure 2, a glass electroforming mother mold is faithfully transferred from an electroforming master (not shown) whose surface is finished with the desired design without being cut. 4 is manufactured by a known plastic molding method, such as injection molding or compression molding. Next, a conductive coating 5 is entirely formed on the inner surface of the plastic electroforming mold 4 by vacuum evaporation or electroless plating to impart conductivity, and then a plateable metal such as nickel, copper, gold, or silver is applied. The electroformed shell 1 is formed by electrodeposition using an electroforming method. Next, electroformed shell 1
is removed from the glass electroforming mother mold 4, finished plated, and then pushed into the plastic reflector 8 as shown in Fig. 3. Next, as shown in Fig. 4, the entire electroformed shell 1 is inserted together with the glass replica 8 into an injection mold 9, and the plastic inner case 2 is injection molded.Then, the plastic replica 8 is peeled off and the watch side case is removed. Finalize.

Here, a method for manufacturing the plastic leglica 8 will be explained. That is, the electroformed shell 1 is made thicker than the electroformed shell 1 and is electroformed to a thickness of about 5III11 to 1OWK that can withstand injection molding, and after the whole is processed into an injection mold, the entire thickness is plated and the plastic replica 8 is molded. This is what we do.

The purpose of thick plating is to transform the electroformed shell 1 into a plastic replica 8.
This is to create a clearance to make it easier to push in.The clearance amount is preferably about 5μ to 10oOμ.The electroforming material of the injection mold processed by electroforming is preferably nickel or copper in terms of cost and quality. , or two layers may be used. After processing the glass insertion part and buttonhole part on the plastic replica 8 manufactured in this way by cutting, press punching, etc., the electroformed shell 1 is coated with a finishing plating layer of precious metal such as nickel, gold, rhodium, etc. Push it in.

Since the shelled case by this IM manufacturing method is made of plastic resin based on the 11°C glass mold for producing the electroformed shell, the shape of the plastic replica and the T-cast shell can be matched. This eliminates the need to shape the shell due to pressure during injection molding, making it possible to perform final plating before injection molding. As described above, according to the present invention, the close contact between the metal shell and the inner shell of the glass nugget is improved, making it possible to manufacture a shelled case with excellent corrosion resistance and finished appearance.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of the watch side manufactured by the method of the present invention, Fig. 2 is a cross-sectional view of the electroformed shell manufactured in the manufacturing process of the present invention,
FIG. 3 is a sectional view of the electric ψj shell pressed into the plastic replica, and FIG. 4 is a sectional view of the mold during insert molding. 1...'6p) Shell 2...Glass snack inner body 3...Crow 4...Glastic electroforming mother mold 5... Turtle membrane 6...
Mask 7...Finish is plating 8...Glasstic replica 9...Insert mold. - Applicant Daini Kigyokusha Co., Ltd. Agent, Patent Attorney, Senior Affairs Officer

Claims (1)

[Claims] The process of producing a plastic electroforming mother mold from an electroforming master, [jIJ] The outer surface of the body is made of one rod or a combination of two or more rods of nickel, copper, gold alloy, etc. The process of producing the constituent electroformed shells, the process of applying finish plating to the first electroformed shell, and the process of inserting the finished electroformed shell into the plastic reflex into an injection mold and injecting it. The glass replica is manufactured by electroforming the inverted shape of the earlier TIF cast shell into a plastic mold, and is injection molded using this mold. Method.