JP2001294491A - Glaze for pottery and glazed pottery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a glaze for a pottery, which is suppressed in change of viscosity without necessitating excess binder, generating a large amount of pulverized mixed residue and lowering of viscosity of the glaze caused by corrosion of the binder by bacteria, and to provide the pottery, which is produced hardly causing discoloration or forming bad appearance or the like in the production process by using the glaze mentioned above. SOLUTION: The process for producing the glaze for the pottery comprises the process of charging raw materials for the glaze, water and a corrosion inhibitor into a pulverizing apparatus, the process of pulverizing and mixing by the pulverizing apparatus, and the process of adding the binder for controlling viscosity to the pulverized and mixed substance. The pottery is obtained by coating the glaze on the surface of a body and firing the coated body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glaze for porcelain and a glazed porcelain.

[0002]

2. Description of the Related Art Ceramic products such as sanitary ware, tiles, tableware and the like are provided with a glaze layer on their surfaces in order to impart design properties. As a method of forming a glaze layer on the surface of a ceramic product, a technique of applying a glaze for ceramic on the surface of a molded substrate and firing the same is generally used.

In the case of industrial products that require uniform design, it is necessary to pay close attention to the properties of the glaze for ceramics to be glazed. For example, when the glaze changes its properties, especially its viscosity, when it is applied, the applied thickness fluctuates,
Glazing, corners and thin vertical glazes on vertical surfaces may occur, resulting in color variation of the product after firing, poor appearance, and the like, and uniform design may not be maintained.

In order to suppress such a change in viscosity of the glaze, a binder having a viscosity adjusting function in water, such as CMC (carboxymethylcellulose), PVA (polyvinyl alcohol) or sodium alginate, has conventionally been added during the preparation of the glaze. ("Glaze and its pigment", Yoichi Sogi, Gihodo Publishing Co., Ltd .; "Powder Molding Handbook", edited by The Japan Powder Industry Technical Association, Nikkan Kogyo Shimbun).

[0005] These commonly used polymer binders such as CMC have the effect of suppressing a decrease in viscosity according to the degree of polymerization, and the higher the degree of polymerization, the greater the effect. I have. For this reason, in order to avoid a decrease in the degree of polymerization due to the pulverization, it is usual to add to the glaze after the pulverization and to carry out stirring and mixing.

On the other hand, it has been found that when a binder is added to the glaze, the viscosity of the glaze decreases due to the corrosion of the binder by bacteria or bacteria. 1 to prevent this
As one method, JP-A-6-9286 proposes a method in which a small amount of paste (binder) and a small amount of disinfectant (corrosion inhibitor) are simultaneously mixed in a mill for pulverizing and mixing glaze materials. .

[0007]

However, in the method of simultaneously mixing a small amount of paste and a small amount of a bactericide in the glaze crushing process, a problem occurs even if they are mixed in any of the crushing steps as described below. .

(1) When a binder (glue) and a corrosion inhibitor (glue) are simultaneously added in the raw material charging stage or in the initial stage of raw material grinding, generally, it takes a long time to sufficiently pulverize the glaze raw material. Because of the need for milling, the milling breaks the binder polymerization and reduces the viscosity increasing effect, resulting in the need for excess binder.

(2) When the binder (glue) and the corrosion inhibitor (glue) are simultaneously added in the latter stage of the raw material pulverization or in the stirring and mixing stage after the raw material pulverization, the corrosion inhibitor is generally powdered. , A large amount of pulverized mixed residues will be generated.

Accordingly, the present invention provides a glaze for ceramics which suppresses a change in the viscosity of the glaze without causing a decrease in the viscosity of the glaze due to corrosion of the binder by bacteria or bacteria, and without causing the above-mentioned problems. It is an object of the present invention to provide a ceramic which is manufactured by using a glaze for ceramics and is less likely to cause color fluctuation, poor appearance, and the like in manufacturing.

[0011]

According to the present invention, in order to solve the above-mentioned problems, a step of charging a glaze raw material, water and a corrosion inhibitor into a crushing facility, a crushing and mixing step of crushing and mixing by the crushing facility, And a step of adding a binder to the pulverized mixture for adjusting the viscosity of the glazed mixture in this order. In this way, the timing of inputting the corrosion inhibitor, which is generally in powder form, is faster than the timing of inputting the binder,
Generation of the pulverized mixed residue is suppressed. Also, by adding at least a part of the binder for adjusting the viscosity after the pulverization and mixing has progressed to some extent, the degree of polymerization of the binder cut off by the pulverization is reduced, the viscosity increasing effect is maintained, and excess It is possible to suppress a decrease in the viscosity of the glaze without using a special binder.

In a preferred embodiment of the present invention,
A step of introducing glaze raw material, water and a corrosion inhibitor into a crushing facility; a first crushing and mixing step of crushing and mixing by the crushing facility; and at least a part of a binder for adjusting viscosity is used in the crushing facility. And a second pulverization mixing step of further pulverizing and mixing by the pulverizing equipment, a step of removing the pulverized mixture from the pulverizing equipment, and, if necessary, transferring the pulverized mixture to a stirring equipment to remove the remaining binder. And a step of adding glazing in this order to provide a glaze for ceramics. In this way, by setting the timing of adding the corrosion inhibitor, which is generally in powder form, earlier than the timing of adding the binder, the generation of the pulverized mixed residue is suppressed. Also, by adding at least a part of the binder for adjusting the viscosity after pulverization has progressed to some extent, the degree to which the polymerization of the binder is cut off by pulverization is reduced, the viscosity increasing effect is maintained, and excessive It is possible to suppress a decrease in the viscosity of the glaze without using a binder. Furthermore, by adding at least a part of the binder for adjusting the viscosity in the grinding equipment,
The viscosity of the pulverized mixture in the pulverizing equipment is appropriately adjusted, and when the pulverized mixture is taken out of the pulverizing equipment, the pulverized mixture remaining in the pulverizing equipment after settling and accumulating is reduced, thereby improving the recovery efficiency. Further, by performing the second pulverizing and mixing step, the binder is uniformly dispersed.

In a preferred aspect of the present invention, the time required for the second grinding and mixing step is 1 to 20% of the total time required for the first grinding and mixing step and the second grinding and mixing step. So that By doing so, the binder becomes a necessary and sufficient uniform mixing state in a relatively short mixing time, so that it is possible to suppress the cutting of the binder polymer by pulverization while securing a sufficient uniform mixing state. Thus, a glaze having a uniform property can be produced without requiring an excessive binder.

[0014] In a preferred aspect of the present invention, the amount of the binder added in the step of adding at least a part of the binder for adjusting the viscosity in the crushing equipment is determined by the total amount of the binder added. It should be at least 10% of the amount. The amount of the binder to be added in the step of adding in the crushing equipment is 10% or more based on the total amount of the binder, so that the crushed mixture remaining in the crushing equipment after settling and depositing is reduced. Recovery efficiency is improved.

In a preferred embodiment of the present invention, the glaze for porcelain according to any one of claims 1 to 4 is applied to a porcelain shaped or fired body and fired to produce a glazed porcelain. By doing so, it becomes possible to produce a ceramic product having a uniform design without causing a variation in coloration of the product after firing and a defective appearance.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, a glaze raw material is
Quartz sand, soda feldspar, potassium feldspar, lithium feldspar, limestone,
Alumina, clay, talc, sodium carbonate, barium carbonate,
A component that remains after sintering of borax, zinc white, dolomite, wollastonite, etc. to form a glaze layer.

In the present invention, the term "corrosion inhibitor" refers to an agent having an effect of killing or preventing the growth of microorganisms such as bacteria and bacteria in the glaze, such as triazine compounds, triiodoallyl alcohol (TIAA), Silver powder or the like can be suitably used.

In the present invention, the binder refers to an organic substance having two functions of a viscosity adjusting function in water and a binder function at least capable of improving the strength of the molded article when the molded article is dried. Specifically, PVA, sodium alginate, CMC sodium salt, CMC ammonium salt, methyl cellulose, cellulose sodium salt,
Sodium polyacrylate, polyethylene oxide,
PVP (polyvinylpyrrolidone), starch, dextrin, various natural rubbers and the like are preferably used.

For the crushing equipment in the present invention, for example, a cylinder mill, a ball mill, a bead mill, etc. can be suitably used.

The porcelain usable in the present invention is not limited to the following. For example, sanitary ware such as a toilet bowl, a urinal, a toilet tank, a toilet sana, a basin, a hand basin, an interior tile, and an exterior It can be used for tiles, tableware, insulators, etc.

Hereinafter, preferred embodiments of the present invention will be described. (1) Preparation of glaze for porcelain Silica sand, soda feldspar, potassium feldspar, lithium feldspar, limestone, alumina, clay, talc, sodium carbonate, barium carbonate, borax
Prepare zinc white, dolomite, wollastonite, etc. These may be melted in advance and a frit obtained by vitrification may be used. As the corrosion inhibitor, a triazine compound, triiodoallyl alcohol, or the like is prepared.

In addition, a deflocculant or a flocculant, a color former, etc. are prepared as required. Here, as the peptizer or coagulant, for example, soda ash, potassium carbonate, sodium silicate, sodium hydroxide, potassium hydroxide, calcium chloride, calcium sulfate, magnesium sulfate, ammonium carbonate, sodium polycarboxylate, polycarboxylate Ammonium acrylate, sodium polyacrylate, ammonium polyacrylate and the like can be used. Further, as the color former, for example, metal oxides such as iron oxide, copper oxide, manganese oxide, cobalt oxide, zirconium oxide, chromium oxide, titanium oxide, antimony oxide, zircon as an emulsifier, tin oxide, etc. Available.

These are weighed in predetermined amounts so as to have the desired composition, properties and color, combined with the prepared water and put into a crushing equipment such as a cylinder mill or a ball mill, and crushed and mixed for a predetermined time. A part of the slurry is extracted on the way and the particle size is measured.
This grinding is repeated until a predetermined particle size is reached.

Thirty minutes to five hours before the end of milling, some or all of the binder is introduced into the milling facility to adjust the viscosity of the mixture. The binder added here is P
VA, sodium alginate, CMC, methylcellulose, cellulose sodium salt, starch, dextrin, various natural rubbers and the like are preferably used. When crushed to a predetermined particle size, the glaze slurry is taken out of the crushing equipment, passed through a refining equipment represented by a vibrating sieve, and if necessary, iron is removed. Move. Here, it is possible to appropriately add a dye for facilitating identification of the remaining binder and glaze. As the dye, methylene blue, methyl violet, malachite green, rhodamine, crystal violet and the like are suitably used.

After that, the glaze properties such as viscosity are adjusted and, before being sent to the glaze process, foreign substances and undissolved binders are removed, if necessary, through a purification facility to obtain a glaze for ceramics.

(2) Preparation of Ceramics First, a ceramic molding base is prepared. Specifically, for example, a base slurry prepared using pottery stone, clay, feldspar, quartzite, or the like as a main raw material is cast into a casting mold formed in advance so as to obtain a molded body having a desired shape, and then demolded. After drying, a dried molded article is obtained. Here, as the casting mold, a casting mold made of gypsum or resin is preferably used. Next, the ceramic glaze prepared in (1) is supplied to a glaze facility, and applied to the surface of the molded body by a method such as flow coating, spray coating, dip coating, curtain hanging, and brush coating. This is an electric furnace,
Ceramic products are obtained by firing in a temperature range of 800 ° C. to 1400 ° C. using a roller hearth kiln, shuttle kiln, tunnel kiln, or the like.

[0027]

EXAMPLES Example 1 Silica sand, potassium feldspar, soda feldspar, wollastonite, talc, zinc white as glaze raw materials, soda ash as a deflocculant and a pigment for coloring are weighed to have the composition shown in Table 1. I do. These were put into a cylinder mill together with water, and the particle size measured by a laser diffraction type particle size distribution analyzer was 1
0% or less is 60%, and 50% average particle diameter (D50) is 7.
The pulverization was performed for a total of 10 hours so that the thickness was about 0 μm. Here, after 5 hours, a triazine-based compound was added as a corrosion inhibitor. Two hours before the end of the pulverization, about half of the total amount of the binder (PVA) was charged into the cylinder and mixed to suppress sedimentation. After the grinding, the glaze slurry is taken out of the cylinder. The remaining binder is added thereto, and the well-stirred mixture is passed through a sieve to remove foreign substances and unmilled coarse-grained raw materials. After the iron removal treatment, the mixture to which an appropriate dye had been added was well stirred, and purified again to obtain a ceramic glaze.

(Example 2) Silica sand, soda feldspar, potassium feldspar, limestone, alumina, dolomite and zinc white as glaze raw materials, water glass and a pigment for color development as deflocculants were weighed so as to have the composition shown in Table 1. I do. In addition, 0.01% by weight of a triazine compound as a corrosion inhibitor and 1.0% by weight of silver powder as an antibacterial material are weighed. These are put into a cylinder mill together with water, and pulverized for 20 hours so that the particle size measured by a laser diffraction type particle size distribution analyzer is about 65% for 10 μm or less and about 6.5 μm for 50% average particle diameter (D50). Was done. One hour before the end of grinding, the binder CMC
Is put into a cylinder for mixing, and after the sedimentation is suppressed, the glaze slurry is taken out of the cylinder.
This is passed through a sieve to remove foreign matter and unmilled coarse-grained raw materials. A mixture obtained by adding an appropriate dye to the mixture was stirred well, and purified again to obtain a glaze for ceramics.

(Example 3) Silica sand, soda feldspar, potassium feldspar, clay, limestone, and frit raw materials as glaze raw materials, caustic soda as a deflocculant, a pigment for coloring, and 0.01% by weight of silver powder as a corrosion inhibitor. Weigh to the composition shown in Table 1. These are put into a cylinder mill together with water, and pulverized for 30 hours so that the particle size measured by a laser diffraction type particle size distribution analyzer is 70% for 10 μm or less and about 50 μm for 50% average particle size (D50). Was done. 30 minutes before the end of the pulverization, about 10% of the total amount of the binder sodium alginate was charged into the cylinder and mixed,
After settling has been controlled, the glaze slurry is removed from the cylinder. The remaining binder is added thereto, and the well-stirred mixture is passed through a sieve to remove foreign substances and unmilled coarse-grained raw materials. A mixture obtained by adding an appropriate dye to the mixture was stirred well, and purified again to obtain a glaze for ceramics.

(Example 4) A tile base slurry prepared using silica sand, feldspar, clay and the like as main components, 100x1
A plate test piece of 00 mm was produced by wet press molding. Next, the glaze for ceramics of Examples 1 to 3 was spray-coated on the test piece, and fired at a temperature of 1200 to 1300 ° C to obtain a ceramic sample. The sample did not have any appearance defects.

(Example 5) A toilet bowl was prepared by cast molding using a sanitary ware base slurry prepared mainly with silica sand, feldspar, clay and the like. Next, the glaze for ceramics of Examples 1 to 3 was spray-coated on necessary portions such as the ball surface, the outer surface of the rim, and the outer peripheral surface of the toilet, and 1100 to 1200.
It was fired at a temperature of ° C. to obtain a ceramic sample. The sample did not have any appearance defects.

[0032]

[Table 1]

[0033]

According to the present invention, the viscosity of the glaze can be reduced due to the corrosion of the binder by bacteria or bacteria without the need for an excessive binder and without generating a large amount of pulverized mixed residue. It is possible to provide a ceramic glaze in which the change in viscosity of the glaze is suppressed, and a ceramic produced by using the ceramic glaze, in which color variation, poor appearance, and the like are less likely to occur in manufacturing.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shingo Kasahara 2-1-1 Nakajima, Kokurakita-ku, Kitakyushu-shi, Fukuoka Totoki Equipment Co., Ltd. (72) Inventor Katsuhiro Kawakami 2 Nakajima, Kokurakita-ku, Kitakyushu-shi, Fukuoka 1-1-1 Toto Kiki Co., Ltd. (72) Inventor Tohru Ueno 2-1-1 Nakajima, Kokurakita-ku, Kitakyushu-shi, Fukuoka Prefecture Touchi Kiki Co., Ltd. (72) Inventor Yasushi Nakajima Kokura, Kitakyushu-shi, Fukuoka 2-11-1, Nakajima, Kita-ku Totoki Equipment Co., Ltd. (72) Inventor Yukinari Matsumoto 2-1-1, Nakajima, Kokurakita-ku, Kitakyushu-shi, Fukuoka Totoki Equipment Co., Ltd. (72) Minoru Suda, Inventor Ryohei Okamoto 2-1-1 Nakajima Nakajima, Kokurakita-ku, Kitakyushu-shi, Fukuoka (72) Inventor Ryohei Okamoto 2-1-1 Nakajima, Kokurakita-ku, Kitakyushu-shi, Fukuoka Within the company (72) inventor Shigeyuki Yamada Kitakyushu, Fukuoka Prefecture Kokura-ku Nakajima 2-chome No. 1 No. 1 TOTO within Co., Ltd.

Claims (5)

[Claims] 1. A step of charging a glaze raw material, water and a corrosion inhibitor into a crushing facility, a crushing and mixing step of crushing and mixing by the crushing facility, and a step of adding a binder for adjusting viscosity to the crushing mixture. Are produced in this order. 2. A step of charging a glaze raw material, water and a corrosion inhibitor into a crushing facility, a first crushing and mixing step of crushing and mixing by the crushing facility, and at least one of a binder for adjusting viscosity. A step of adding a part in the crushing equipment, a second crushing and mixing step of further crushing and mixing by the crushing equipment, and a step of removing the crushed mixture from the crushing equipment, and transferring the crushed mixture to a stirring equipment as necessary. And a step of adding the remaining binder in this order. 3. The time required for the second grinding and mixing step is as follows:
3. The glaze for ceramics according to claim 2, wherein the amount is 1% to 20% with respect to a total required time of the first pulverization / mixing step and the second pulverization / mixing step. 4. 4. The amount of the binder added in the step of adding at least a part of the binder for adjusting the viscosity in the crushing equipment is 1 to the total amount of the binder.
The glaze for ceramics according to claim 2 or 3, which is 0% or more. 5. A glazed porcelain obtained by applying the glaze for porcelain according to any one of claims 1 to 4 to a porcelain shaped or fired base and then firing.