JPS6359473B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a timepiece dial. More specifically, the purpose is to provide a low-cost dial.

In the current dial manufacturing method, the process that has become the key to reducing costs is the typesetting process.

This is because the current typesetting process for dials involves manually planting multiple letters onto the completed dial, and cannot be mechanized or automated.

The reason why the text typesetting process cannot be mechanized or automated is that automatic text feeding is difficult. Automatic feeding of characters is extremely difficult because there are many types of characters and they have complex shapes, making it difficult to line them up.Also, if characters come into contact with each other, they will be scratched, resulting in poor appearance.

The method for manufacturing a dial plate of the present invention simplifies the process mainly in the typesetting process of characters, and provides a method for manufacturing a dial plate that is easy to mechanize and automate.

The manufacturing method centered on the current letter typesetting process will be explained in more detail.

First, the current method of manufacturing characters will be described.
Press the surface onto the brass plate to form the letter feet and letters. Figure 1-1), 4) Next, punch out the letters with a press. Figure 1-2),
5) Next, perform barre polishing to remove burrs from the press punch. Next, apply a Ni undercoat. Next, the tops of the letters are cut with diamonds, and the final plating is applied to complete the letters. Figure 1-3), 6) Next, the process of typesetting the completed characters 1 onto the completed dial base board 2 will be explained.

First, manually grasp the completed character 1 with tweezers and insert the character foot into the character hole of the completed dial base plate 2.

Next, from the back side of the completed dial base board 2,
Pour the adhesive into the letter hole on the dial base plate and insert the letter 1.
The dial is completed by fixing it to the completed dial base plate. Figure 2 As mentioned above, the work of manually inserting characters is
Typesetting of characters is difficult due to the fact that a large number of characters, at least 11, must be placed on one dial plate, and the width and thickness of characters have become smaller as designs have diversified recently. The process is extremely time consuming and the work involved is extremely demanding.

The present invention transforms the above-mentioned current manual typesetting process into a production process that can be mechanized and automated.

A method for manufacturing a dial plate of the present invention will be explained.
Using a letter mold with concave letter parts, photosensitive resin is poured onto it, and then a plastic film and a mask with white letter parts are placed on top of that, and after being irradiated with ultraviolet rays, it is developed. .

Next, the plurality of plastic letters formed in the recesses of the letter molding die are transferred to a film coated with an adhesive on one side to form a thin metal layer on the surface of the plastic letters.

Next, the letters on which the thin metal layer has been formed are again transferred to the recesses of the letter mold.

Finally, a watch dial is produced, characterized in that the completed characters transferred to the character mold described above are adhered to the completed dial base plate.

As described above, the dial manufacturing method of the present invention is such that the characters used on at least one dial can be printed at the same time, the typesetting process is performed at least once for each dial, and it is easy to mechanize and automate. It is easy to perform, and furthermore, it has features that allow batch processing and continuous processing by hooping to create multiple dials at the same time, making it possible to provide dials at an unprecedentedly low cost. .

The manufacturing method of the present invention will be explained in more detail with reference to the drawings.

First, a character mold 3 having a concave character portion is prepared. The concave letters are placed in the same position and in the same number as the dial to be completed.

The material of the mold is preferably a urethane-based or silicone-based rubber mold. In particular, the commercially available silicone rubber silpot 184 or 186 manufactured by Tau Yuning Co., Ltd. is most suitable because it is transparent, has excellent transferability, has a relatively short curing time, and has excellent mold durability.

Above, character mold 3 using Silpot 186
Explain how to make.

First, the desired letters are machined, and a master is prepared by placing 12 letters on a flat plate (for example, a metal plate) in the same position as the desired dial.

Next, mix the main agent and hardening agent of Silpot 186 at a ratio of 10:1.
Mix in the following proportions and vacuum devacuole. Next, pour the vacuum-deflated Silpot 186 into the master,
After vacuum removal, the silicone rubber will harden if left in an atmosphere of 80℃ for 60 minutes. After curing, the master is peeled off to complete a silicone rubber character mold 3 with concave character parts.

The silicone rubber mold mentioned above has very good transfer accuracy and dimensional accuracy. For example, the diamond cut surface of the letters can be transferred as is, and since it is cured at low temperature under atmospheric pressure, there is very little distortion, so it is also good in terms of dimensional accuracy. It is possible to create characters almost identical to the master.

A photosensitive resin monomer 4 is poured onto the above-mentioned character molding mold with concave character parts, and the photosensitive resin monomer 4 is made to have a uniform thickness over the entire surface of the mold using a squeegee.

Next, a PET film 6 with a thickness of 10 μm is set on the photosensitive resin monomer coated evenly. Further, on the PET film 6, a mask 7 with white text portions is superimposed. The mask 7 is set so as to overlap the concave character portion of the character mold 3. Figure 3-1) As the photosensitive resin monomer, it is desirable to use a commercially available photosensitive resin letterpress material for letterpress printing.

For example, there is APR photosensitive resin manufactured by Asahi Kasei.

In the above operation, it is important that only the photosensitive resin monomer 4 is filled between the character mold 3 and the PET film 6 to prevent air from entering.

Next, when UV (ultraviolet light) is irradiated from the mask side 7, the UV is transmitted only to the white portions of the mask, and the photosensitive resin monomer 4 is cured by photopolymerization, and a photosensitive resin polymer 5 is formed. Figure 3-2) When Asahi Kasei's APR photosensitive resin is used, it cures in 60 seconds at an ultraviolet intensity of 5 mmW/cm ² .

Next, peel off the PET film 6 and mask 7,
When the photosensitive resin monomer 4 is dissolved by development, plastic letters 5 made of a photopolymerized photosensitive resin polymer are formed in the recesses of the letter mold 3. Figure 3-
3) When APR is used, a 1% NaOH aqueous solution is used as the developing solution, and the developing time is 1 minute at a solution temperature of 35°C.
Next, the 12 plastic characters 5 already formed in the recesses of the character mold 3 are transferred onto a plastic film 8 coated with an adhesive on one side so as not to shift their positions. (Fig. 3-4) Next, a metal film layer 9 is formed by a wet method or a dry method on the entire surface of the plastic film on which the plastic characters 5 have been transferred onto the adhesive-coated plastic film. Figure 3-5) The metal thin film layer 9 was formed by a wet method using Hitachi Chemical's electroless Ni process, and the photosensitive resin was treated to form a metal thin film with a thickness of 1000 Å on Asahi Kasei's APR. We were able to form a Ni thin film layer with a good glossy surface.

In addition, the dry method uses a low-temperature sputtering device,
When sputtering Cr to a thickness of 500 Å, we were able to form a Cr thin film layer with good adhesion and a glossy surface.

Next, the metallized characters 5 are inserted into the recesses of the character mold 3, and at the same time, the adhesive-coated plastic film 8 is peeled off from the characters, and the metallized characters 5 are transferred to the character mold 3. Third
Figure 6) Next, a transparent thermoplastic hot melt adhesive is applied to the entire surface of the completed dial base plate 2 to a thickness of 10 μm, and the letters that have already been molded into the letter mold 3 and have been metallized are adhered ( As shown in FIG. 3-7), a dial plate is completed by the manufacturing method of the present invention. Figure 3-
8) The above is for characters, but window frames other than characters,
Marks can also be used in the same way as characters.

As described above, the dial manufacturing method of the present invention makes it possible to mechanize and automate the manual typesetting process, which is the most difficult process in the current dial manufacturing methods, and furthermore, It has the characteristics of being able to process a large number of dial plates at the same time by batch processing and continuous dial plate processing by forming hoops, thereby providing a dial plate at an unprecedentedly low cost.

[Brief explanation of the drawing]

Figure 1 is cross-sectional views 1, 2, and 3 of the character manufacturing process using the conventional machining method, and corresponding plan views 4, 5, and 6. A cross-sectional view of a completed dial plate using letters,
1 to 8 in FIG. 3 show cross-sectional views of manufacturing steps according to the dial manufacturing method of the present invention. 1 is a letter formed by a conventional machining method, 2 is a dial base plate completed by a conventional processing method, 3 is a letter mold, 4 is a photosensitive resin monomer, 5 is a photosensitive resin polymer, 6 is a plastic film, 7 is a mask, 8 is a plastic film with adhesive,
9 indicates a metal thin film layer.

Claims (1)

[Claims] 1 Using a letter mold with concave letter parts, pour photosensitive resin monomer onto it,
Furthermore, a plastic film and a mask with white letters are placed on top of that, exposed to UV rays, and developed. Next, the film is coated with an adhesive on one side and formed in the recesses of the letter mold. A metal layer is formed on the surface of the plastic letters, and then the plastic letters with the thin metal layer are transferred again to the letter mold, and finally, the above letter mold is transferred. 1. A method for manufacturing a watch dial, characterized in that plastic letters whose surfaces have been transferred to a metallized surface are adhered to a completed dial base plate.