JPH02239172A - Production of nonglazed pottery having pattern - Google Patents

Abstract

PURPOSE:To produce the nonglazed pottery having various kinds of patterns without generating cracks and breaking patterns by applying a pottery slurry for patterning on the surface of pottery base molded product, and then drying and calcining the slurry. CONSTITUTION:The pottery slurry contg. the pottery base material itself or fillers essentially consisting of the pottery base material mixed with a binder and pigment is applied in the form of patterns on the surface of the pottery base molded product prior to drying. After the coating is dried, the surface is polished with polishing paper to expose the fillers and to smooth the surface. The molded product is then calcined after this polishing and is further subjected to buffing. The nonglazed pottery beautifully generated with the patterns of stone grains like the stone grains of natural stone without generating the cracks is produced.

Description

[Detailed Description of the Invention] Industrial Application Fields The present invention relates to a method for producing patterned unglazed ceramics, particularly for toilet bowls, wash basins, and counters. This invention relates to a method for producing unglazed products such as sanitary ceramics such as tiles and accessories, ceramic curtain stones, and ceramic crafts.

[Prior Art] Generally, when creating stone tones, flow patterns, or patterns of various colors on the surface of porcelain, a method is usually used in which a glaze is applied to the surface of the molded product and then fired.

On the other hand, some ceramic products are manufactured as unglazed ceramics, and the method of creating patterns on the surface of such unglazed ceramics is to use base powder containing fillers and pigments to form the patterns. There are two methods: one-piece molding using a dry press method or slurry casting method (referred to as the first method), or a method where a slurry containing filler or pigment that becomes a pattern is applied to the mold surface and then the slurry is poured into the mold ( There is a second method).

Problems to be Solved by the Invention> However, when the first method is used, the base material containing the filler and MFA that forms the pattern usually has low plasticity;
When casting, there is a risk of cracks occurring.
Furthermore, it is not possible to produce multi-M shaped products using a dry press method or the like. Furthermore, since the entire molded product is made of a base material containing fillers and pigments, there is a drawback that the cost is high. In addition, with the second method, it may be difficult to apply slurry containing filler or pigment to create a pattern on the surface of the mold depending on the shape of the mold, and if molded using a highly productive dry press etc., the pattern on the surface may be difficult to apply. Since the mold is broken, only the cast molding method, which has low productivity, can be used.

The present invention has been made in view of the above-mentioned problems of the prior art, and its purpose is to
It is an object of the present invention to provide a method that can be manufactured easily and at low cost, even in the case of complicated shapes, without the risk of cracks occurring or the pattern being broken.

<Means for Solving the Problems> In order to achieve the above object, the method for manufacturing unglazed ceramics having a pattern according to the present invention includes applying a ceramic slurry to create a pattern on the surface of a ceramic base molded product. Afterwards, it is dried and fired.

In this invention, the method of molding the ceramic base molded product is not particularly limited, and any molding method can be used. For example, dry pressing can be used for plate-shaped products, extrusion molding can be used for tubular products, and plastic pressing, casting molding, etc. can be used for products with complicated shapes.

Furthermore, the method of applying ceramic slurry to create a pattern on the surface of a molded product is not particularly limited, and methods such as spray brush coating, dipping, etc. may be selected depending on the shape and pattern of the molded product. It can be used.

In addition, the timing of application may be before the molded product is dry, in a semi-dry state, or after drying; if deformation of the molded product is a problem, apply after drying, but if the adhesion of the coated slurry to the molded product is a problem, apply it after drying. In this case, it is preferable to do so before drying. However, if the molded product does not contain moisture from the beginning, such as in dry press molding, the result will be the same no matter when the coating is applied.

An example of a ceramic slurry for creating a pattern is one containing a filler, which is suitable for creating a stone-like pattern imitating natural stone. In this case, if the filler used is from a ceramic base material similar to the ceramic clay slurry used to create patterns, cracks are less likely to occur because the filler and base matrix exhibit approximately the same firing shrinkage.

As a method for producing this ceramic filler, there are methods of drying a ceramic base slurry to which a binder and pigment have been added, then crushing and sieving it, or forming it into granules using a spray dryer method, etc. .

Another example of ceramic slurry used to create patterns is one that contains pigments, which can be used to create various patterns by combining the coating pattern and the color of the pigment when applied to the molded product. can.

The ceramic slurry used to create the above-mentioned patterns varies in moisture a
need to be adjusted.

For example, when applying a filler-containing slurry with a spray gun, the water loss (weight of water relative to the weight of the slurry) is 35
-% is appropriate. This is considerably higher than the moisture content of normal casting slurry (approximately 30%), but the reason for this is that it contains fillers and binders, which increases its viscosity, and for spray application, lower viscosity is required. This is because it is preferable.

The thickness of the ceramic slurry applied to create the pattern is not particularly limited, but is preferably 0.2 to 5 m. It is thick to create a deep pattern, and to prevent cracks from occurring during drying and firing. It is preferable to apply it thinly.

The base composition of the ceramic slurry for patterning may be the same as the base composition of the molded product, or it may be different, but if the same base composition is used, the shrinkage of the fired product will be the same. This has the advantage of reducing the risk of cracks occurring during firing.

In addition, if it is necessary to reduce the water absorption from the surface of the fired product, the base component of the ceramic slurry for patterning may be made to have a lower fire resistance than that of the molded product. However, if it is not possible to lower the fire resistance of the base component of the ceramic slurry used for patterning, due to the physical properties of the slurry during application and the need to match the firing shrinkage with the base of the molded product, after firing, The water absorbency of the surface may be reduced by impregnating the surface with a resin liquid containing unsaturated polyester, vinyl monomer, etc.

Note that depending on the method of applying the ceramic slurry to create the pattern, the surface may not be sufficiently smooth, and in this case, after the slurry has dried, it is necessary to polish the surface using cloth abrasive paper, etc. be.

In addition, if the ceramic slurry used to create patterns contains filler, depending on the viscosity of the slurry and the amount of filler,
In some cases, the filler does not fully come out on the surface, or conversely, a portion of the filler protrudes from the coated surface.In such cases, after the applied slurry dries, the surface is polished to expose the filler. It is necessary to smooth the surface. In this case, polishing is easier if the filler is made of ceramic material.

Further, in order to give the surface of the product gloss or to further improve the surface smoothness, the fired product can be polished after firing. As a polishing method for fired products, 1-
Polishing with an abrasive, two puffs of coated abrasive paper, and the like is used.

Examples Example 1 A filler-containing slurry was sprayed two times thick on a molded article made of a vitreous china base consisting of 59 parts by weight of pottery stone, 25 parts by weight of clay, and 16 parts by weight of feldspar. The composition of the filler-containing slurry is 59 parts by weight of pottery stone, 8 parts by weight of clay, 25 parts by weight of clay, 16 parts by weight of feldspar, 20 parts by weight of filler, 100 parts by weight of water, and 0.3 parts by weight of water glass. C-M-C (binder) 0.3
Parts by weight. The filler was made of ceramic material and consisted of 59 parts by weight of pottery stone, 25 parts by weight of clay, 16 parts by weight of feldspar, 10 parts by weight of zircon, and 5 parts by weight of pigment.

After the sprayed slurry had dried, the surface was polished using abrasive paper to expose the filler and smooth the surface. After polishing, it is fired at a maximum temperature of 1180℃,
The baked product was given a puff finish.

The surface of the product had a pattern similar to that of natural stone, and no cracks were observed.

(Example 2) The same molded article as in Example 1 was brush-coated with a pigment-containing slurry to a thickness of 15M. The composition of the pigment-containing slurry is 55 parts by weight of chinastone;
25 parts of clay, 20 parts of feldspar, 65 parts of water, 10 parts of pigment, 0.3 g part of water glass, and 0.1 part by weight of C-M-C (binder).

After the brushed slurry had dried, the surface was polished using abrasive paper to make it smooth.

After polishing, the product was fired at an RB temperature of 1180°C.

There were no broken patterns or cracks on the product.

<Effects> Since the method for manufacturing unglazed ceramics having a pattern according to the present invention is configured as described above, it produces the effects described below.

■Since the patterned layer is only on the surface of the product, the use of expensive pigments and fillers can be saved.

■Since it is not necessary to use a slurry with small plasticity for creating patterns in molding the molded product, there is less risk of defects such as cracks occurring during molding and drying (of the molded product).

■As a molding method for molded products, various molding methods such as powder pressing, plastic molding, and cast molding can be used depending on the shape of the product and productivity requirements.

■A variety of patterns can be created by adding fillers or pigments to the slurry used to create patterns, or by combining polishing after drying or firing.

■Since the slurry for patterning is applied to the product after molding is completed, the process is not only simpler compared to the conventional method of applying slurry for patterning to the mold and then molding.
It is easy to pattern products with complex shapes, and there is no fear that the pattern will be damaged.

Claims (7)

[Claims] (1) A method for producing unglazed ceramics, which comprises applying ceramic slurry to create a pattern on the surface of a ceramic molded product, followed by drying and firing. (2) The method for manufacturing ceramics having a pattern according to claim (1), characterized in that the surface of the ceramic molded article coated with ceramic slurry is polished after drying and before firing. (3) A method for manufacturing ceramics having a pattern according to claim (1), which comprises polishing the surface of the fired product. (4) The method for manufacturing unglazed ceramics having a pattern according to any one of claims (1) to (3), wherein the ceramic slurry for forming the pattern contains a filler. (5) The method for producing unglazed ceramics having a pattern according to claim (4), wherein the filler is made of ceramic material. (6) The method for manufacturing unglazed ceramics having a pattern according to claim (4), wherein the filler is formed into granules from a slurry mainly composed of a ceramic base to which a binder and a pigment are added. (7) Claims (1) to (3) characterized in that the ceramic slurry for patterning contains a pigment for coloring.
A method for producing unglazed ceramics having a pattern as described in any of the above.