JPH05262583A - Production of decorative ceramic - Google Patents

Abstract

PURPOSE:To provide a means for readily obtaining a varied ununiform pattern in a method for producing a ceramic in which the pattern is formed to the interior of the ceramic. CONSTITUTION:The surface of a body for a ceramic or unburned raw glaze is coated with an acidic aqueous solution of a soluble metallic salt which is colored by burning or colored even at a burning temperature and then with an alkaline aqueous solution for neutralizing the metallic salt and subsequently burned. Thereby, a metallic hydroxide gel in which aggregation is stopped by permeation into the internal surface and neutralizing the metallic salt is formed to develop a color unique to the metallic oxide by burning. An irregular pattern is produced by ununiformly coating the surface with the alkaline aqueous solution for neutralization.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a decorative ceramic product, and more particularly to a method for producing a decorative ceramic product which forms an irregular pattern even inside the product.

[0002]

2. Description of the Related Art Recently, due to diversification of needs of consumers, ceramic products such as tiles and porcelain plates having various patterns formed on their surfaces have been used.

Among the methods for forming such a pattern, the most general method is a method of printing on a base material or a glazed surface, a method of transferring and decorating after baking at a temperature lower than the baking temperature, or , A method of mixing an inorganic pigment or a metal oxide with a binder and decorating with a brush or a spray.

However, in such a method, the pattern formed is superficial, and the decoration itself has little depth. In particular, in places where the surface is worn due to use, such as floor tiles, the pattern disappears, so there is a limit to use.

Therefore, as a method of solving such problems and forming a pattern even in the inside of the product, a method of forming a concave portion in a mold, filling the concave portion with a kneaded clay containing a pigment, and baking it A method by so-called sand blasting, in which sand or the like is blown onto the surface of the base material under high pressure, and JP-A-2-284678.
As described in Japanese Patent Laid-Open Publication No. 2004-242242, there has been developed a production method in which a liquid pigment of a chelate compound is sprayed onto the surface of a ceramic product base, the liquid pigment is allowed to penetrate into the ceramic product base, and then the ceramic product is baked.

In particular, the method described in JP-A-2-284678 has an advantage that a pattern can be formed without going through the process of processing the surface to the inside of the ceramic product base.

[0007]

However, in this method, the liquid pigment of the chelate compound is permeated into the ceramic product base material at a uniform concentration, and this is repeated many times in order to produce a partial shade. And it is difficult to obtain a variety of patterns. In addition, since it uses an inkjet printer, it can be applied to spot decorations, but it takes time when the decoration area becomes large, and in addition, to control the penetration depth of the liquid pigment, It is necessary to manage it well.
Furthermore, when a liquid pigment is applied on a porous portion such as an unsintered glaze applied to the base material, the liquid pigment penetrates to the base material, and it is difficult to control the decoration.

It is an object of the present invention to provide a means for easily obtaining a pattern rich in unevenness in a method for manufacturing a ceramic product in which a pattern is formed inside the ceramic product.

[0009]

According to the present invention, an acidic aqueous solution of a soluble metal salt that develops color by firing or is colored even at firing temperature is applied to the base material or unfired raw glaze of a ceramic product, and then the surface thereof. The object was achieved by applying an aqueous alkali solution for neutralizing the metal salt to form a metal hydroxide gel, and then calcining.

As the soluble metal salt aqueous solution, conventionally known ones can be used, and examples thereof include Co, Ce, Cr and
Fe, Ni, Cu, Pr, Sm, Eu, Yb, Y, L
A 0.5 to 30% aqueous solution of a metal salt such as Au is used, and this is appropriately applied by spraying, writing, screen printing or the like on the base or unbaked raw glaze of the ceramic product. .

As the alkaline aqueous solution for neutralizing the applied metal salt, any aqueous solution can be used, but ammonium hydroxide, sodium hydroxide or the like can be preferably used.
Similar to the soluble metal salt aqueous solution, this is appropriately applied by a means such as spraying, writing, or screen printing according to the concentration or application amount of the previously applied metal salt aqueous solution.

As a result, the aqueous solution of the metal salt that has penetrated into the base material of the ceramic product is neutralized to form a metal hydroxide gel and stop permeation. In addition, an irregular pattern appears by applying the neutralizing alkaline aqueous solution unevenly.

After drying, it is heated to 1050 to 1250 ° C. by a kiln such as a tunnel kiln or a roller hearth kiln.
It is preferably fired at 1100 to 1200 ° C.

As a result, a ceramic product is obtained in which the metal gel that has stopped permeating into the substrate becomes a metal oxide by firing and develops a color, and an irregular pattern is formed even inside.

[0015]

[Function] The acidic aqueous solution of the soluble metal salt applied to the ceramic product permeates to the inside of the base material, and the applied alkaline aqueous solution causes the metal ions to be evenly dispersed.
The permeation stops as a metal hydroxide gel that is agglomerated inside the substrate.

[0016]

【Example】

Example 1 A mixture soil of 20% by weight of feldspar, 20% by weight of porcelain stone, 20% by weight of silica stone, and 40% by weight of clay was pressed into a flat plate of 300 × 300 × 5 mm and fired at 1180 ° C. for 12 hours. Write a 4% cobalt nitrate aqueous solution on the surface of the tile substrate,
Then, spray a 4% ammonium hydroxide aqueous solution over it nonuniformly, and let it air-dry for 24 hours, then at 1050 ° C.
The firing was done at Laura Hearth Kiln for 1 hour.

As a result, a bright cobalt blue irregular ground pattern was obtained. When the inside was confirmed by polishing, a bright pattern similar to the surface was confirmed up to 2 mm from the surface.

Example 2 Mixed soil of 50% by weight of porcelain stone, 20% by weight of limestone and 30% by weight of clay was pressed into a flat plate of 300 × 300 × 8 mm and fired at 1150 ° C. for 24 hours on a tile base material. ,
Using a bell-type glaze machine, a glazing consisting of 20% by weight feldspar, 15% by weight silica, 5% by weight clay, 8% by weight zircon, 42% by weight frit, 3% by weight lime, and 7% by weight zinc white is 0.35 mm thick. Glazed on. Then add 0.1% Aerosil to 2% praseodymium nitrate solution to give 1
After printing large and small circular patterns using a 50-mesh screen, immediately spray a non-uniform 3% sodium hydroxide solution over the entire surface, then dry for 4 minutes with an infrared lamp and bake at 1100 ° C for 1 hour. went.

As a result, large and small circular patterns of cobalt blue having clear irregular shades on the surface were obtained. When the inside was confirmed by polishing, the same bright pattern was confirmed from the glaze surface to the base body by about 3 mm.

[0020]

【The invention's effect】

(1) By applying an aqueous solution of alari on an acidic aqueous solution of a soluble metal salt applied to a ceramic product, the metal hydroxide gel is stopped to agglomerate on the inner surface of the base material, and the variation inside the base material is uneven. Can be obtained.

(2) The degree of penetration into the inner surface can be easily controlled by adjusting the concentration and amount of the aqueous metal solution.

(3) There is no limitation on the decorative portion, and the inner surface can be easily decorated without lowering the productivity.

(4) Even a porous member such as a glaze-treated unsintered glaze surface can be easily decorated to the inner surface.

Claims (1)

[Claims] 1. An acidic aqueous solution of a soluble metal salt that develops color by firing or is colored even at the firing temperature is applied to the ground or unfired raw glaze of a ceramic product, and then the surface thereof is neutralized with the metal salt. A method for producing a decorative ceramic product, which comprises applying an alkaline aqueous solution to form a metal hydroxide gel and then firing the gel.