JPH08100275A - Thinly enameled panel and its production - Google Patents

Abstract

PURPOSE: To thin an enameled panel, to facilitate the cutting of the panel into desired shape and size and to reduce the production cost and weight. CONSTITUTION: A glaze having high contents of boron oxide, nickel oxide and copper oxide or the glaze further mixed with cristobalite or tridymite or both is applied on a base steel sheet in <=1.0mm thickness, the glaze is fired at about 770 deg.C which is lower than the normal firing temp. to form a fired enamel layer in about 100μm thickness, the substrate firing and then finish firing are separately conducted, and a lower glaze and then the upper glaze are applied when the substrate is fired. Consequently, the utilization of the enameled panel is promoted in the field not used conventionally such as the inner wall of the kitchen, interior and exterior walls of the building and door.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin enamel panel which is easy to cut at a construction site and is less likely to cause peeling of a porcelain enamel firing layer on the surface, and a manufacturing method thereof.

[0002]

2. Description of the Related Art Enamel is a material in which a vitreous coating is applied on a metal and adhered to it, and is made of a material having both the durability of metal, the corrosion resistance and cleanliness of glass.

The production method is enamel, which is prepared by adding a mill additive to a pre-vitrified compound called frit and pulverizing it into fine powder with a mill to adjust its concentration and PH to prepare a enamel suspension. The glaze is applied onto a base steel sheet and fired.

[0004] This glaze coating firing is usually carried out twice, undercoating and finishing, in order to prevent the occurrence of pinholes.

The lower glaze used for undercoating is required to adhere to the base metal first, and contains an oxide such as cobalt, nickel, manganese, or molybdenum that chemically assists adhesion between glass and iron. And the firing temperature is 80
It is 0-920 degreeC.

The upper glaze used for finishing is mixed with an opacifying agent such as antimony oxide, tin oxide, zirconium oxide, and titanium oxide in order to hide the color and roughness of the lower glaze containing the above-mentioned adhesion metal. The firing temperature is 800-8
90 ° C.

As described above, enamel is produced by applying a glaze on a steel plate as a base material and then firing it. However, in the case of using the conventional enamel glaze described above, in order to form a good enamel. , The lower glaze requires a thickness of 80 to 100 μ, and the upper glaze requires a thickness of 100 to 150 μ, and 800 to 92
In order to prevent distortion due to a high firing temperature of 0 ° C., the base steel sheet also needed to have a thickness of at least 1.2 mm or more.

It has also been practiced that the base steel sheet is subjected to a surface treatment so that the top glaze is directly applied on the base steel sheet, and the glaze is applied and fired only once. Since it is necessary to apply it thicker than in the case of 1. and the firing is also performed at 800 to 920 ° C., the thickness of the steel sheet is also required to be 1.2 mm or more.

[0009]

In the conventional enamel panel described above, the thickness of the steel plate that is the base is as thick as 1.2 mm or more, and the thickness of the enamel firing layer formed on the surface of the enamel panel is lower glaze and upper glaze. Since it is relatively thick with about 180-250μ, the cutting process is difficult, and the enamel peeling or chipping (chip) is likely to occur on the cut end face of this panel when cutting, in which case metal corrosion However, there is a risk that the enamel panel will not perform its original function.

For this reason, conventionally, the enamel panel has not been required to be cut and has been mainly used for kitchen units and bathroom units formed by assembling standard-sized panels, which has a problem that the field of use is limited. Was.

An object of the present invention is to solve the problems of the conventional enamel panel.

[0012]

In the present invention, in order to solve the above-mentioned problems, the glaze is produced with a frit in which the proportion of boron oxide, nickel oxide, and copper oxide is increased more than that of the usual enamel glaze, and The glaze was applied onto a steel plate having a thickness of 1.0 mm or less, and this was baked at a temperature of 800 ° C. or lower which is the lower limit of the usual enamel baking temperature.

Further, cristobalite, tridymite, or both of them are mixed as a mill additive for the glaze.

The glaze coating and firing process is divided into the first firing of the base enamel and the second firing of the finished enamel, and the glaze coating for firing the base enamel is performed by applying the lower glaze and the upper glaze. It was decided to perform it in two steps of applying the glaze.

[0015]

[Function] Copper oxide mixed in the frit acts on the alkaline side during firing, depositing a copper-like substance on the iron surface, which prevents iron oxide from rising to the enamel surface. To work.

Further, nickel oxide acts to improve the adhesion between the base steel sheet and the glaze by the strong adhesion of iron-nickel.

Further, boron oxide acts so as to improve the wettability of the glaze to the steel plate during glaze application.

Cristobalite and tridymite mixed in the glaze as a mill additive act to improve the expansion coefficient, and reduce the difference in expansion coefficient between the enamel and the base steel sheet on which this enamel is fired to reduce enamel firing. It is intended to improve the peel resistance of the layer.

Forming the base enamel by two-step application of lower glaze and upper glaze and low temperature firing suppresses the precipitation of iron oxide and the formation of pinholes on the surface of the glaze layer, and the firing of the thin enamel layer In addition to making it possible, the strain of the base steel sheet on which the enamel layer is formed is reduced.

[0020]

EXAMPLE A thin enamel panel of the present invention has a thickness of 1.0 mm.
Although an enamel firing layer having a thickness of about 100μ is formed on the following base steel sheet, in the method of the present invention for producing this thin enamel panel, a glaze having a composition different from the conventional one is used, The technique for coating and firing is different from the conventional technique.

The production of a thin enamel panel by the method of the present invention will be described below based on examples.

First, in the method of the present invention, boron oxide of 20% to
Frit having a composition of 4% lithium oxide, 0.3% cobalt oxide, 2.8% nickel oxide, and 0.5% copper oxide (the raw material is melted in glass and then poured into water to be rapidly cooled). ) Was used to add an additive, and the mixture was pulverized with a mill to produce a glaze.

Then, 20 μ of this glaze is applied as a lower glaze on a base steel sheet having a thickness of 1.0 mm or less, dried, and then 20 μ of an upper glaze is similarly applied, which is then applied.
Firing at 0 ° C. formed the first base enamel.

Thereafter, the same glaze as above was applied to the base enamel in a thickness of 60 μ, and this was glaze at about 770 as above.
A second finish enamel was formed by firing at ° C.

Thus, in the method of the present invention, the enamel is fired at a relatively low temperature of 800 ° C. or lower, which is the lower limit of the usual enamel firing temperature, using a glaze containing a relatively large amount of boron oxide, nickel oxide and copper oxide. It was made to be done.

As described above, since the glaze used in the method of the present invention has a high mixing ratio of boron oxide, nickel oxide and copper oxide, it has a high wettability with the base steel sheet during glaze and is in close contact with the base steel sheet during firing. The property is improved. In addition, since low-temperature firing is possible, iron oxide does not easily rise to the surface of the enamel during firing, and the enamel layer is formed without the occurrence of pinholes in combination with the above-mentioned two-step glaze coating and one-step firing of the base enamel. It can be formed extremely thin (about 100 μ).

Further, since the firing temperature is low, distortion of the base steel sheet due to heat is small, and it becomes possible to use a steel sheet having a thickness of 1.0 mm or less and up to about 0.4 mm, and the thin enamel panel described above is manufactured. Is.

It is also possible to use the above glaze further mixed with cristobalite or tridymite as a mill additive. In this case, the expansion coefficient of the enamel layer can be approximated to that of the base steel sheet, and firing It is possible to further reduce the distortion and further improve the peel strength of the enamel layer. For example, it was confirmed that when 10% of cristobalite was added to the glaze, the expansion coefficient increased by 20 to 30 × 10 ⁻⁷ / ° C.

As described above, according to the method of the present invention, 1.0 mm
The following enamel panel can be easily cut with a diamond saw, etc., because a porcelain enamel layer with a thickness of 100μ can be firmly adhered to this base steel sheet without causing distortion. While being able to
At that time, peeling and chipping of the enamel are extremely reduced. Therefore, it will be promoted to use in a field that was not expected in the past, where it is cut to the required size at the construction site and used, for example, the inner and outer walls of the building and oil stains tend to adhere. It will be easy to obtain a material that will not deteriorate for many years by covering the inner wall surface of the kitchen with an enamel panel.

[0030]

As described above, in the method for manufacturing an enamel panel of the present invention, since the firing temperature is relatively low, the distortion of the steel sheet due to heat is reduced and the rise of iron oxide on the enamel surface is also reduced. . Therefore, a thin steel plate can be used and the enamel layer can be formed thin.

Further, by applying the base enamel separately to the lower glaze and the upper glaze, the pinholes that cause the deterioration of the quality of the product are almost generated in spite of the extremely thin enamel layer combined with the above-mentioned low temperature firing. Absent.

Since the glaze used contains a large amount of boron oxide, nickel oxide, and copper oxide, it has good adhesion to the steel plate, and peeling or chipping of the enamel is unlikely to occur when cut. Furthermore, when cristobalite or tridymite is added to the glaze as a mill additive, the expansion coefficient of the enamel is improved, and the difference between the expansion coefficient of the steel sheet is reduced, and the strain during firing is further reduced, and the enamel layer resistance is increased. Peel strength is further improved and high quality thin enamel panel can be manufactured.

Therefore, it becomes possible to provide a thin enamel panel which can be easily cut, and can be applied to a field requiring cutting on site such as a kitchen inner wall surface which has hardly been adopted due to its poor workability. It has many excellent effects that cannot be seen in the past.

Claims (4)

[Claims] 1. About 1 on a base steel sheet having a thickness of 1.0 mm or less.
A thin enamel panel characterized in that an enamel firing layer having a thickness of 00μ is formed. 2. A glaze produced from a frit containing at least 20%, 2.8%, and 0.5% of boron oxide, nickel oxide, and copper oxide, respectively, is thinly formed on a steel plate having a thickness of 1.0 mm or less. A method for producing a thin enamel panel, which comprises applying and firing the coating at a relatively low temperature of 800 ° C. or lower. 3. The method for producing a thin enamel panel according to claim 2, wherein a glaze mixed with cristobalite or tridymite or both of them is used as a mill additive. 4. The glaze coating and firing process is divided into a first firing of the base enamel and a second firing of the final enamel, and the glaze is applied to the lower glaze when firing the base enamel. The method for producing a thin enamel panel according to claim 2 or 3, which is performed in two steps of applying the upper glaze.