JPS621340B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a three-dimensional glass dial using an etching method.

Conventionally, some high-quality dials for watches have used precious stones such as onyx and tiger eye, or used glass instead of precious stones, which is inexpensive and has a certain degree of luxury. All of these materials have a luxurious feel due to their flatness and depth due to their transparency or translucence. In other words, it creates a sense of luxury from the dial surface toward the thickness direction.

On the other hand, methods to create a sense of luxury and three-dimensionality from the dial surface upwards include typesetting letters and marks that indicate the time, etc., or stamping out letters and marks by pressing the material. It is taken.

However, since both precious stone dials and glass dials are made of fragile materials, they cannot be punched or pressed for typesetting, so the characters and marks are formed by printing, and are formed on the dial surface. It was not possible to obtain a sense of luxury and three-dimensionality from above.

The present invention improves the above-mentioned drawbacks, and
To provide a method for producing a glass dial plate that has a more luxurious feel than precious stones by forming three-dimensional pear-based characters/marks on the upper surface of the dial while taking advantage of the flatness and depth of the glass body.

Hereinafter, the present invention will be explained in detail based on Examples.

Example: D263 glass with a thickness of 0.4 mm and a diameter of 30 mm with good flatness (trade name of Shot Co., Ltd., composition: SiC ₂ 68%,
Na ₂ O 7%, Al ₂ O ₃ 4%, K ₂ O 6%, BaO 0.8%,
B ₂ O ₃ 9%, ZnO 4%) Zinc powder with a diameter of 5μ or less is dispersed on one side at a density of 70 pieces/mm ² . The distribution method is
The above-mentioned zinc powder is mixed and dispersed in a solvent such as water or alcohol, and then sprayed and dried by a method such as spraying. The density of the dispersed zinc can be controlled by the amount of zinc in the sprayed solution and the spraying time.

The fine metal powder to be dispersed on the glass surface can be any metal except gold and platinum, which are insoluble in fluorine-based etching solutions such as hydrofluoric acid, but in this example, inexpensive zinc powder was used. The diameter of the metal powder is 50μ or less. If a metal powder larger than this is used, the pear pattern formed on the surface of the character mark will be too large and the appearance will deteriorate significantly, which is not preferable.

In addition, the density of the fine metal powder to be dispersed is 51 pieces/mm ²
That's all. If it is less than 50 pieces/mm ² , the pear-ground appearance will be insufficient, the contrast with the flat area will be small, and three-dimensional expression will be lacking.

Next, as shown in FIG. 1, a tin oxide film 3 of 500 Å was formed on the glass surface 2 in which zinc powder 1 was dispersed by chemical vapor deposition. The thickness of tin oxide film 3 is
100Å or more and 1μ or less, preferably 300Å to 3000Å
It is. If the thickness is less than 100 Å, there will be many pinholes in the tin oxide itself and it will be difficult to control the number of pinholes, which is undesirable.If the thickness of the tin oxide film is more than 1 μm, cracks will easily occur and the masking effect will be reduced as well as pinholes. This is not preferable because the number of pinholes cannot be controlled. When the thickness is 300 to 3000 Å, the tin oxide film has almost no pinholes and is dense, making it suitable as an etching mask.

Next, a photoresist was applied onto the tin oxide, and the letters and marks of the watch dial were patterned using a photoetching method, and the unnecessary portions of the tin oxide were etched. Etching of tin oxide was carried out using active hydrogen gas generated by applying hydrochloric acid to zinc powder. citric acid 200
Etching properties similar to those described above can be obtained by etching with a solution of 1 g/g of metallic chromium dissolved in 500 c.c./500 c.c. of hydrochloric acid, but the present invention is not limited to the method of etching tin oxide.

After etching the tin oxide, the glass was etched using the solution and conditions shown below.

49% hydrofluoric acid 80c.c./Glycerin 50c.c./Temperature 60℃ Time 60 minutes This etching solution attacks glass and zinc, but does not attack tin oxide, so it is possible to remove glass with a cross section as shown in Figure 2. etched. The etching depth was 120μ.

Fluoric acid attacks most metals, but its etching rate is relatively slow, so zinc is not quickly depleted during a 60 minute etching time. Therefore, the tin oxide film containing zinc powder has a surface 4 with many pinholes with a relatively shallow depth. By dispersing zinc powder at a constant density on the glass surface in this way, it was possible to control the density of tin oxide pinholes, and it was possible to form letters and marks with a beautiful pear-ground appearance.

On the other hand, the surface 5 and back surface 6 without the tin oxide film were etched extremely uniformly, and the flatness before etching could be improved.

When the density of pinholes is 50 pcs/mm ² due to the zinc on the etching mask surface, a remarkable contrast appears between the etched flat surface and the blank surface of the characters/marks, as shown in Figure 3. The present inventor has discovered. This produced an effect in which the characters/marks 4 appeared to stand out from the flat glass surface 5.

After etching the glass in this way, it is not necessary to remove the tin oxide film used as a mask using the etching method described above, but it is better to remove it if the etched surface is to be used as it is for the appearance of the dial. This is because tin oxide has a higher refractive index than ordinary glass, making the tin oxide surface unusually glaring.

Next, the dial was completed by applying black paint to the back of the glass. As can be seen in the cross section shown in Figure 2, the etched surface 5 is a flat mirror surface with a deep appearance due to the black paint on the lower side.
The surface of the letters and marks reflects light diffusely and appears white, creating a beautiful contrast. Furthermore, since the etched interface of the glass has a taper of 70 to 80 degrees, letters and marks appear raised in three dimensions, resulting in a more beautiful appearance.

The dial manufactured in this manner provides a three-dimensional effect that cannot be obtained with conventional precious stone or glass dials, and has the appearance of a high-class dial.

In the embodiment shown in the present invention, letters and marks were selected as the etching mask pattern, but any pattern can be easily created using the mask. In addition, there are many possible ways to process the glass after etching, such as depositing a metal film on the etched surface, or forming a translucent film on the etched surface and painting or vapor depositing it on the back surface. However, the present invention is not concerned with the details.

As described above, the present invention is a practically useful invention because it is possible to manufacture a high-class glass dial plate using inexpensive materials and a simple manufacturing method.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the glass surface after dispersing zinc powder and then forming an oxide film, FIG. 2 is a sectional view of the glass after it has been etched, and FIG. 3 is a plan view of FIG. 2. 1 is zinc powder, 2 is glass, 3 is a tin oxide film, 4 is a pear surface due to an etching mask, 5 is a dial surface, and 6 is a dial back surface.

Claims (1)

[Claims] 1. In the process of manufacturing a glass dial for a watch, (1) fine metal powder with a diameter of 50μ or less that is soluble in a solution for etching the glass is added to one side of a flat glass.
A process of dispersing at a density of 51 particles/mm ² or more. (2) 100Å on the glass surface with fine metal powder dispersed
The process of forming a tin oxide (SnO ₂ ) film with a thickness of 1μ or less. (3) A process of removing unnecessary portions of tin oxide by photoetching, etc. (4) A process of etching the glass by 5μ or more using the remaining tin oxide film as a mask. (5) A process of forming a metal film, oxide film, or organic film on the uneven surface or the flat back surface of the glass. A method for manufacturing a glass dial for a watch, characterized in that the steps are performed in this order.