JPS5811882A - Cover glass for timepiece - Google Patents

Abstract

PURPOSE:To obtain metallic luster on an inorganic glas surface at low cost without spoiling its nature, by printing liquid gold on or lustering the inorganic glass surface in some patterns after degreasing, washing and drying, and then burning the surface. CONSTITUTION:The surface of a cover glass 1 for a timepiece which is made of inorganic glass is degreased, washed, and then dried. On the surface, liquid gold or a lustered metallic film 2 is printed in characters, patterns, etc., and then burned. Gold and white colors are obtained by the gold of liquid gold luster and platinum. Gold and platinum, however, have low sticking strength for glass, so metals such as a sticking agent, a reaction accelerator, and a lustering agent, are added. Those metals have natural color tones, and form a reaction layer 3a with the glass surface and a reaction layer 3b with gold or platinum, giving a unique alloy color.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cover glass for a watch, which has a metallic luster brand name, display characters, patterns, etc. applied to the surface of an inorganic glass.

Conventionally, when forming brand names, display characters, patterns, etc. with a metallic luster on the surface of a watch cover glass made of inorganic glass, a metal film was formed on the entire surface of the inorganic glass using a vapor phase method, such as vacuum deposition. However, this was accomplished by later applying a resist film on the metal film and etching the parts without the resist film. The commonly used gold color has poor adhesion to glass, and the coating is soft and easily scratched, so this problem can be solved by forming multiple layers of metal coatings. Therefore, there are many vacuum evaporation steps and etching steps, resulting in a disadvantage that the manufacturing cost is very high. Therefore, it is currently only used in some high-end watches. However, watch cover glasses with metallic luster brand names, display characters, patterns, etc. are rich in aesthetic expression and have a sense of luxury, so they are indispensable as cover glasses for watches.

The present invention has been made in view of the drawbacks of the above-mentioned conventional examples, and an object of the present invention is to provide a very inexpensive cover glass for a watch that has a metallic luster without impairing the conventional texture. Furthermore, the present invention aims to enhance the appearance of low-priced watches by providing a high-class cover glass for low-priced watches that do not pay much attention to texture.

The gist of the invention is as described in the claims.

Next, the present invention will be explained based on examples. To degrease the surface of a watch cover glass made of inorganic glass and formed into a predetermined shape, and sufficiently remove oil, fat, dirt, etc. adhering to the glass surface. Afterwards, the glass surface is neutralized with acid or alkali, thoroughly washed with water, and the surface is dried.

Be careful not to cloud or stain the glass surface after drying. Afterwards, a predetermined brand name, display characters, patterns, etc. are applied to the glass surface by printing water gold or lascoux by, for example, screen printing or tacho printing. Water gold or raster is composed to have printable viscosity or drying properties. Water/metal or raster will be explained in detail later. Next, the printed glass is fired in an electric furnace or the like. Firing is performed by gradually raising the temperature from room temperature to near the glass softening point. The adhesion of water gold or Lascou to glass can be obtained at a temperature near the glass softening point. Rapid cooling can cause the glass to chip, crack, or deform, so slow cooling is performed to prevent this. After firing, the predetermined pattern etc. applied by printing appears on the glass surface with the unique metallic luster of water gold or raster.

. However, although the fired glass has good strength when the glass 1 is thick, in recent years cover glasses for watches have become thinner, for example, glass of 1.5 mm (millimeter) or less. The strength is low, so it is necessary to strengthen the glass after firing. The reinforcement may be performed by a generally known low temperature ion exchange method using potassium nitrate or the like. The watch cover glass obtained as described above has a texture similar to that obtained by conventional vapor phase methods, such as vacuum evaporation, and can be manufactured in two steps, printing and firing, compared to the conventional process. It can be manufactured cheaply.

Water gold or raster has been used for a long time as a top paint on ceramics, and for decoration with a metallic luster, in processes such as brush painting. The former type of water gold is a reddish-brown, low-viscosity liquid with aromatic compounds that contains gold sulfide resin, and is baked to obtain a fully mirrored surface while simultaneously adhering it to the inorganic glass substrate.

The viscosity of the liquid is so low that printing is not possible and requires modification of the composition. Generally, gold is used to give a golden color, and platinum-rhodium, palladium, etc. are used to give a white color. As for white metals, Jintong does not use the above-mentioned metals alone, but as an alloy of each metal. Gold or platinum in water gold does not adhere well to glass, and may be near the glass softening point, e.g.
Since it does not melt at 60°C to 580°C, a small amount of metal such as an adhesive or a reaction accelerator is added. An example of the analysis is shown in Table 1.

An example of water gold analysis The latter raster is made of metal or metal oxide, and is produced by dissolving metal resinates in essential oil-based solvents, and like the water gold mentioned above, it is a low viscosity liquid. In order to print, a change in composition is required. There are two types of raster: colored raster and colorless raster. Colored raster includes iron, copper,
Manganese, cobalt, uranium, gold, platinum, etc. are generally known, and colorless rasters include aluminum, zinc,
Commonly known materials include tin, bismuth, and titanium. The color tone of colored raster can be freely changed by changing the metal or metal oxide that constitutes the raster. Furthermore, since raster has a metallic luster, it is possible to obtain the same texture as color vapor deposition. In the case of color vapor deposition, the color is created by interference between multiple layers of thin films, making it extremely difficult to control and difficult to manufacture, but in the case of Lascoux, all you have to do is change the metal or metal oxide that is the main component in the raster. , very easy to manufacture. Colorless Lascou is translucent and −
Depending on the angle of the reflected light, it becomes colored due to interference and has a glassy luster, so it has a more luxurious feel compared to conventional medium or clear lacquers made of organic resins, and when used in combination with conventional organic resin inks, A watch cover glass with an unprecedented texture can be obtained.

The present invention is applied by modifying the composition to a viscosity that allows printing of water gold or raster as outlined above. According to the present invention, it is very easy to form a gold or platinum color, or even a pattern with metallic luster, on a watch cover glass, and it is very inexpensive compared to conventional methods, and it has a luxurious feel that is rich in aesthetic expression. It is possible to obtain a watch cover glass with a

The present invention is an application of the one used in ceramics, etc., but in carrying out the present invention, it is necessary to draw the drawings to clarify the differences in the use of conventional water metal or raster or the point that it is not a mere application. The following is an explanation based on the following. 1st
The figure is a cross-sectional view showing a metal film 2 of water gold or Lascou and a reaction layer 3 formed on the surface of an inorganic glass 1 after firing. The gold and white colors commonly used for watch cover glasses are made of water gold or lascoux gold, and platinum. Gold and platinum have poor adhesion to glass, and for this reason, metals such as adhesives, reaction accelerators, and brighteners are added as described above. These metals have their own unique color tone, or have a reaction layer 3 with the glass surface.
It forms a reaction layer 3b with gold or platinum, and has a unique alloy color. FIG. 2 shows a cross-sectional view of the metal layer on the inorganic glass, showing the progress of thermal diffusion during the firing process. Heat diffusion due to firing progresses from the metal layer 2, for example, the surface layer 2a of gold or platinum, and advances to the interior 2b of the metal layer 2. Therefore, a film is formed on the surface 2a of the metal layer 2, and the resin, etc. is not completely burned in the interior 2b of the metal layer 2, and the metal layer has a different color tone and gloss than the metal layer 2 or the surface 2a of the metal layer 2. The interior 2b of 2 is formed. Metal layer 2 and metal layer 2
0 surface 2a is formed with the same color tone and gloss. FIG. 3 is a cross-sectional view of a substrate 1 made of inorganic glass or the like with a metal layer 2 of water gold or lascoux applied by painting with a brush or the like. In the case of painting by brush painting, etc., as shown in FIG. 3, - non-uniformity of film thickness occurs within the same cross section.

In the thick portion, the reaction layers 3a and 3b are thick, and an inner portion 2b of the metal layer 2 having a different color tone and gloss from the metal layer 2 is formed. As described above, the metal layer 2 and the surface 2a of the metal layer 2 are formed with the same color tone and gloss.

The properties of water metal or raster after firing have been described above, but in ceramics etc., the metal layer 2 is shown in direction A as shown in Fig. 1, and in Figs. 2 and 3 for a more direct external view. As shown in the figure, there is no problem even if the reaction layers 3a and 3b or the inside 2b of the metal layer 2 occur, and even if the painting or firing etc. is very A pattern with . Furthermore, even if there is non-uniformity in film thickness, it can be visually observed directly from direction A, so
Metal layer 2 and surface 2 of metal layer 2 having the same color tone and gloss
Since you will be able to visually check a, the painting will be very rough. Rather, the three-dimensional effect of the metal layer 2 can be created by performing the painting roughly and creating non-uniformity in film thickness. On the other hand, the board 41
Regarding the adhesion of the metal layer 2 on the inorganic glass made of Even if 2b is generated inside the complete metal layer 2, a sufficient amount can be obtained. As mentioned above, in the case of ceramics, material deformation due to the heat of firing is relatively rough, and products can be obtained simply by firing painted objects.

However, the reason why the cover glass according to the present invention has not been applied in the past is that the attachment of the metal layer 2 to the substrate made of inorganic glass is achieved at a temperature near the softening point of the inorganic glass, which prevents deformation and chipping of the substrate 1. This is because there is a reason why this happens easily. Furthermore, II whose external viewing direction is different from that of ceramics
) Since it is in the B direction, the color tone, gloss, or reaction layer 3 of the adhesive etc.
This was because the color tone and gloss of a and 3b interfered with the color tone and gloss of the metal layer 2, which was unfavorable in terms of appearance quality.Furthermore, the interior 2b of the incompletely fired metal layer 2 turned black, resulting in a watch cover. This is because it did not have the quality of glass.

Therefore, in the past, the current situation has been to rely on vapor phase methods, such as vacuum evaporation, and in order to obtain cover glasses for watches that are aesthetically pleasing and luxurious, it is unavoidable that the manufacturing costs are high. Ta.

However, the present invention has been made to overcome the above-mentioned problems, and when printing water gold or raster by, for example, Nuclean printing, the entire printing film thickness is thinned using a high mesh plate, and the same cross-sectional view is printed. To reduce the non-uniformity of the film thickness,
By strictly controlling the time and temperature in a cyclic atmosphere such as N5af during firing, and by strictly cleaning the surface of the inorganic glass, it is possible to obtain the same texture as the conventional gas phase method. . Although the work required to be carried out extremely precisely, this was resolved by standardizing the work, and it became possible to mass-produce a large number of products of the same quality.

As described above, according to the present invention, it is possible to produce a cover glass for a watch that has an aesthetically pleasing and luxurious appearance with the same quality as the conventional vapor phase method and at a low cost. Furthermore, by providing the watch cover glass of the present invention to low-priced watches, it is possible to upgrade the low-priced watches.

[Brief explanation of the drawing]

FIG. 1, FIG. 2, and FIG. 3 are cross-sectional views showing the formation of a metal layer on a substrate made of inorganic glass after firing of water gold or raster. l...Substrate 2 made of inorganic glass...Metal layer 2a of Au, Pt, etc....Metal layer surface 2b...Metal layer interior 3a...Reaction layer with inorganic glass 3b...Au, Reaction layer with Pt etc. Patent applicant Kawaguchiko Precision Co., Ltd. θ Fang/Ku Fang 2 Fig. Fang 3

Claims (1)

[Claims] The surface of the inorganic glass is degreased, washed, and dried, and by printing water gold or raster on the surface of the inorganic glass to form a pattern, etc., and then firing, the pattern etc. is given a metallic luster, and further, the inorganic glass A cover glass for watches that has been subjected to a strengthening process. “