JPH0254284B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a tempered glass plate in which a ceramic masking is applied to the upper side and the like to block a portion of incident light for the purpose of blocking light.

Recently, tempered glass sheets have been produced that have an anti-glare effect by baking a ceramic color onto the upper side of an automobile windshield or the like to form a colored semi-transparent film.

The conventional manufacturing method for such tempered glass sheets is to apply a paste-like ceramic color to the upper side of the glass sheet, suspend the glass sheet with tongs, and place it in a heating furnace. Ceramic masking is applied to the surface of the glass plate by heating and strengthening the plate and baking a ceramic color at the same time.

However, recently, glass plates have become larger and thinner, and the weight of the glass plate is placed on the upper side of the glass plate in the heating furnace.
Furthermore, many ceramic colors are black or brown, and have extremely good heat absorption. When these factors are added together, the upper side of the glass plate, especially the portion supported by the tongs, expands during heating, making it impossible to satisfy the allowable dimensional error. In addition, the areas coated with ceramic color become very hot due to their good heat absorption properties, and due to heat conduction from these high-heat areas, the transparent parts of the glass plate near the areas coated with ceramic color become hotter than other transparent parts. As a result, the transparent portion near the area where the ceramic color is applied becomes more distorted.

The present invention has been made to solve the above-mentioned conventional problems, and its purpose is to provide a method for manufacturing tempered glass in which a ceramic masking is formed with high dimensional accuracy and low transparency distortion. It is in.

In order to achieve such an object, the present invention first applies a ceramic color to a part of a glass plate, and then coats the surface of the ceramic color with a heat shielding material made by dissolving diatomaceous earth powder or the like coated with a silicone film in water. However, by heating the glass plate after drying this heat shielding material, the glass plate is strengthened and the ceramic color is baked on at the same time.

An example of the implementation of the present invention will be explained in detail below based on the accompanying drawings.

Figure 1 shows the first step of the method of the present invention. First, a ceramic color made of a paste of low-melting glass mainly composed of PbO, SiO ₂ , etc. and an inorganic pigment is mixed with a silicone film. A heat shielding material made into a paste by mixing coated diatomaceous earth powder with appropriate amounts of glue (starch) and water is prepared.

Then, as shown in FIG. 1, the above ceramic color is applied to the upper side of the glass plate 1 by screen printing to form a ceramic color layer 2. After drying this ceramic color layer 2, the above heat shielding material is applied. It is applied to the surface of the ceramic color layer 2 using a brush or the like to form a layer 3 of heat shielding material.

Then, after the layer 3 of the heat shielding material has dried, the second layer 3 is dried.
As shown in the figure, the upper side of the glass plate 1 is grasped with tongs 4, and while the glass plate 1 is suspended, the glass plate 1 is placed in the heating furnace 5 as shown in FIG. Then heat the glass plate 1 at about 700°C for about 3 minutes. Then, the ceramic color is fired and firmly attached to the surface of the glass plate 1.

Thereafter, the glass plate 1 is taken out from the heating furnace 5 and rapidly cooled to generate compressive strain on the surface of the glass plate 1, thereby forming a tempered glass. Then, the glass plate 1 is washed with water to wash away the heat shielding material. In this way, a tempered glass plate with the desired ceramic masking applied is obtained.

The above is just an example of the implementation of the present invention. For example, after applying a heat shielding material and before drying, dry diatomaceous earth powder (coated with a silicone film) can be applied with a brush, etc. It's okay to make progress. In this way, the amount of diatomaceous earth powder deposited increases and is more effective. Other heat shielding materials include, for example, magnesium oxide, magnesium carbonate, or a mixture of barium sulfate and zinc sulfide as white pigments, which are important in that they reflect infrared rays, do not react with ceramic paste and glass, and are washable with water after baking. It is fine as long as it can be removed. The reason why the heat shielding material is dried after being applied is because if moisture is not removed, bumping will occur during heating, resulting in pinholes and cracks in the ceramic collar.

Next, the effects of the present invention will be explained by citing specific numerical values.

First, the heat shield material, which is made by coating diatomaceous earth powder with a silicon film, reflects infrared rays and absorbs little heat, so it reduces the temperature difference between the ceramic collar part and other parts of the glass plate when heated. becomes. Specifically, if we show the results of measuring the glass temperature on the back side of the glass coated with ceramic color using a thermoviewer, we can see that although in the past, the temperature of the part coated with ceramic color was 25°C to 30°C higher than other parts. On the other hand, when the above heat shielding material is applied, the temperature difference can be suppressed to 10°C to 15°C. Therefore, it is possible to greatly reduce the distortion of the transparent part in the vicinity of the part to which the ceramic color is applied. Furthermore, since the temperature of the area to which the ceramic color is applied does not rise to high temperatures, hanging elongation can be reduced and the glass dimensional tolerances will not be exceeded. Furthermore, since the heat shielding material is made of a material with a high melting point as described above, the ceramic color paste does not adhere to the press mold during press molding. In addition, the above heat shielding material does not react with either ceramic color or glass, so
It has many effects, including no adverse effect on the ceramic masking after firing, and can be easily washed away with water, so there is no disadvantage of complicating the manufacturing process of the tempered glass plate.

[Brief explanation of the drawing]

The drawings show an example of the implementation of the present invention,
Figure 1 is a cross-sectional view of a glass plate with a layer of heat shielding material applied to the surface of the ceramic color layer, Figure 2 is a front view of the same glass plate suspended with tongs,
FIG. 3 is a sectional view of the glass plate placed in the heating furnace. In the drawings, 1 is a glass plate, 2 is a ceramic color layer, 3 is a layer of heat shielding material, and 5 is a heating furnace.

Claims (1)

[Claims] 1. A ceramic color is applied to a part of the surface of a glass plate, and then a heat shielding material is applied to the surface of the ceramic color, and after this heat shielding material is dried, the glass plate is heated. A method for manufacturing a tempered glass plate with ceramic masking, characterized in that a ceramic color is baked on the glass plate and then the glass plate is rapidly cooled. 2. The method of manufacturing a tempered glass plate with ceramic masking according to claim 1, wherein the heat shielding material is washed away by washing with water after the glass plate is rapidly cooled.