JPS642672B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing an enameled product having a convex pattern.

For example, the bottom of an enameled bathtub is provided with an uneven pattern to prevent slipping.

Conventionally, this type of uneven pattern has been formed by inserting a glass molded body or a plastic molded body into the enamel layer. However, such post-processing is not desirable because it is time-consuming and there is a risk of damaging the enamel layer.

The purpose of the present invention is to improve the conventional drawbacks and form an uneven pattern at the same time as firing the enamel, and the present invention aims to fuse a glass molded body having the following composition to the enamel layer by firing. This is the basic outline.

SiO ₂ 58~68% by weight Na ₂ O 25~35 〃 CaO 1~ 6 〃 B ₂ O _{3 0} ~ 10 〃 Al ₂ O ₃ 0~ 5 〃 CaF ₂ 0~ 5 〃 Sb ₂ O ₃ 0~ 5 〃 There are two firing methods and one firing methods for carrying out the method of the invention.

The double-firing method is a method in which a base material such as iron, stainless steel, or aluminum is glazed, fired once to form an enamel layer, and then a glass molded body in a predetermined shape is placed on the enamel layer and fired again. .
At this time, to apply the glaze to the substrate, either a wet method is applied, in which glaze slurry is poured onto the substrate, and it is applied by spraying or dipping, or a dry method is applied, in which glaze powder is sprinkled on the substrate. Methods include a method in which glaze powder is sprinkled onto a heated substrate and fused, and a method in which glaze powder is adhered to the substrate by electrostatic coating.

After the base material is glazed, if a wet method is used, it is pre-dried if desired and then fired to form an enamel layer. Firing at this time is usually carried out at around 800°C for several minutes.

An enamel layer is thus formed, and a glass molded body having a predetermined shape and having the above composition is placed on the enamel layer. At this time, it is desirable to temporarily fix the glass molded body with an adhesive, but the adhesive is preferably one that completely decomposes and volatilizes when fired, such as methacrylic resin, urethane resin, or cellulose derivative. Alternatively, the glass molded body may be temporarily fixed by pressing the glass molded body while the enamel layer is in a heat-softened state after firing. Further, temporary fixing may be performed by applying a glaze over the glass molded body by a wet method to form a covering glaze layer. After this, the glass molded body is fired again to soften it and fuse it onto the enamel layer. Firing at this time is carried out for several minutes at a temperature above the softening temperature of the glass molded body, usually about 600 to 800°C.

Next, the one-time firing method is a method in which a glass molded body is immediately placed on the glazed layer and fired at the same time, without glazing and firing the base material, which reduces the number of steps compared to the two-time firing method, and This method is highly praised because there is no risk of deterioration or damage to the enamel layer due to reheating. At this time, a wet method or a dry method is applied, similar to the double firing method of applying glaze to the base material.
What is desirable is to sprinkle glaze powder on the heated base,
This is a method in which a glass molded body is placed on the sprayed layer and pressed slightly. Since the sprinkled glaze powder is softened by the high temperature of the base, the glass molded body can be temporarily fixed without using an adhesive. Therefore, the adhesive does not remain as a residue after firing and has no adverse effect on the enamel. If the glaze is applied by a wet method, care should be taken because the glazed layer is likely to be damaged by the placement of the glass molded body.

The firing conditions are around 800°C for several minutes, and in this way the glazed layer becomes an enamel layer and the glass molded body is fused to the enamel layer.

It is desirable that the glass molded article used in the present invention can be easily molded into any desired shape, and secondly that it should not become cluttered during firing. It is also desirable that the softening point is higher than that of the glaze so that it does not lose its shape during firing. The glass molded article having the composition of the present invention described above satisfies these conditions.

In the above glass composition of the present invention, the softening temperature is
The softening temperature of the glaze is about 600℃, which is higher than the softening temperature of 500-560℃.
Moreover, the coefficient of body expansion is in the range of 300 to 400, so it is difficult to cause clutches during heating-cooling cycles, so it can be easily molded with a mold, and it is also difficult to cause clutches during firing. Furthermore, it is extremely easy to color.

In the above composition, if SiO ₂ is less than 58% by weight (hereinafter simply referred to as %) and Na ₂ O is more than 35%, the coefficient of body expansion will exceed 400 and clutches will easily occur during mold forming, and SiO ₂ 68% or more, _Na2O is 25%
If it is below, the coefficient of body expansion will be less than 300 and cracks will easily occur during firing.

Examples for explaining the present invention more specifically will be described below.

Example 1 After heating a casting base and sprinkling emulsion glaze powder as a lower glaze, it was fired at 950°C for 1 minute, and while the lower glaze layer was in a heated state, a transparent glaze and colored transparent antimony glaze were applied as an upper glaze. After applying the glaze, etc., it is fired at 950℃ for 1 minute. While the upper glaze layer is in a heated state, a semicircular spherical glass molded body having the composition shown below is placed on the upper glaze layer, slightly pressed to temporarily fix it, and then fired at 950℃ for 1 minute, resulting in enameling. The layer and the glass molded body are integrated to obtain an enameled product in which a convex pattern is formed.

The composition of the glass molded body according to this example is as follows.

SiO ₂ 62.0% Na ₂ O 29.0%, CaO 2.5% B ₂ O ₂ 2.0% Al ₂ O ₃ 1.2% CaF ₂ 1.5% Sb ₂ O ₃ 2.3% The glass molded body with the above composition has a softening temperature of 600℃ and the glaze softens. Since it is higher than the temperature, it does not lose its shape during firing, and its coefficient of expansion is 350×10 ^-7 , so it has good moldability and does not easily crack during firing.

Example 2 After heating the iron plate base and scattering the lower glaze powder
Firing was carried out at 820°C for 2 minutes, and while the lower glaze layer was in a heated state, a powder of transparent glaze, emulsion glaze, etc. was sprinkled as an upper glaze, and immediately a glass molded body having the composition of Example 1 was poured over it. After pressing and temporarily fixing, 820℃,
If baking is performed for 2 minutes, a convex patterned enamel product with a glass molded body fused to the enamel layer can be obtained.

Example 3 A lower glaze was applied to an iron plate base using a wet method, and the glaze was heated at 820℃ for 2 hours.
After firing for 2 minutes, a transparent glaze, emulsion glaze, etc. is applied as a top glaze using a wet method, and firing is performed at 820°C for 2 minutes to obtain an enamel layer. After temporarily fixing the glass molded body having the composition of Example 1 on the above enamel layer with carboxymethyl cellulose (CMC),
A convex patterned enamel product can be obtained by firing at ℃ for 2 minutes.

Example 4 In Example 3, the glass molded body was not temporarily fixed with CMC, but was placed on the enamel layer and immediately glazed with transparent glaze etc. using a wet method to form a covering glaze layer, and then heated at 820°C for 2 minutes. By firing, a convex patterned enamel product can be obtained.

Claims (1)

[Claims] 1 After forming an enamel layer by applying a glaze to the base material and firing it, SiO ₂ 58-68% by weight Na ₂ O 25-35 〃 CaO 1-6 〃 B ₂ O ₃ 0- 10 〃 Al ₂ O ₃ 0 - 5 〃 CaF ₂ 0 - 5 〃 Sb ₂ O ₃ 0 - 5 〃 A glass molded body having the following composition is placed on the enamel layer and fired again to form the enamel layer. A method for producing a convex-patterned enamel product, which comprises fusing a glass molded body to a enamel product. 2. In the method for producing a convex pattern enamel product as set forth in "Claim 1", a glaze is applied to the base material by a dry method. 3. In the method for producing a convex pattern enamel product as set forth in "Claim 1," a glaze is applied to the substrate by a wet method. 4 After applying glaze to the substrate, SiO ₂ 58-68% by weight Na ₂ O 25-35 〃 CaO 1-6 〃 B ₂ O ₃ 0-10 〃 Al ₂ O ₃ 0-5 〃 CaF ₂ 0-5 〃 A convex pattern enamel product characterized in that a glass molded body having a composition of Sb ₂ O ₃ 0 to 5 is placed on the glaze layer and fired to fuse the glass molded body onto the enamel layer. Production method. 5. In the method for producing a convex pattern enameled product as set forth in "Claim 4," a glaze is applied to the base material by a dry method. 6. In the method for producing a convex pattern enamel product according to claim 4, a glaze is applied to the substrate by a wet method.