JP2608473B2 - Lightweight ceramic tile and its manufacturing method - Google Patents

Description

The present invention relates to a method for manufacturing a lightweight ceramic tile, the use of which is in the kiln industry, and the product is used in the construction field.

(Prior Art) Conventional ceramic tiles have been manufactured by molding a mixture of earth or stone powder and clay and firing the mixture using fire heat.
Therefore, a conventional ceramic tile uses the above clay mixture, and is extruded by a vacuum forming machine into a clay having a water content of 20 to 24%, or a powdery clay having a water content of 5 to 10% is formed into a mold. It was manufactured by putting it into a press and then firing it without glaze or after glazing. This is described in “Ceramic Engineering Handbook”, Gihodo Shuppan, Vol. 5, published on April 10, 1989, pp. 1552 to 1554 of ceramic products.

On the other hand, regarding the manufacturing method of ceramic products with reduced weight, the technology is described in 10.2 of `` 10. Porous porcelain '' on pages 227 to 228 of `` Porous Materials '' Gihodo, 1973, published in 1973. Manufacturing methods are introduced. Examples include mixing ceramic particles with a certain range of particle diameters with a suitable medium solvent and sintering, combining ceramic particles with a certain range of particle sizes with appropriate plastics, phenolic resin, etc., and using ceramic materials as raw materials. Porcelain, and a suitable method such as adding an appropriate combustible agent and a foaming agent to form a large number of pores.
Creating a large number of pores.

(Problems to be solved by the invention) Conventionally, ceramic tiles (= ceramic tiles)
When trying to make it lighter, the density of the tile was measured by making it thinner. For a thick tile, the weight cannot be reduced by the conventional manufacturing method. This is because when extrusion molding or press molding employs the above methods, uniform pores can be obtained, but pores also appear on the exposed surface side of the tile surface, which is very visible. However, the surface strength was low and it was not suitable for glaze. The present invention seeks to provide a tile having a dense tile surface and a porous inside.

(Means for Solving the Problems) In the present invention, the tile is made porous, but a dense surface is formed on the surface side. In the means for forming a coarse part and a dense part in one tile, first, a combustible agent (burnt material) is mixed into a clay (ceramic slurry). The apparent specific gravity of the burned material at this time is
It is preferable that the apparent specific gravity of the ceramic slurry containing no burnout material is 0.1 or more, and the viscosity of the ceramic slurry containing burnt material is preferably in the range of 1000 cps to 10,000 cps. Next, a molding method is divided depending on whether the ceramic slurry has self-curing property or not. When the former has the property of thermosetting, thermogelling or water setting,
It can be formed one by one or continuously according to a mold having a tile cross-sectional shape. Curing is performed by applying heat or kneading water in the slurry, but it is necessary to allow time for the burnt material to separate in the tile mold before curing. When the other ceramic slurry has no self-hardening property, the productivity is deteriorated, but casting or vibration casting can be used. However, in the conventional casting, there is a case where time for separating the burnt material is not obtained. Therefore, a method of coating the interface of the mold with a water-soluble substance or the like is used to limit the water absorption time in the mold. The tile or tile block thus formed is reduced in size to one sheet, glazed and fired if necessary.

The ceramic powder used in the present invention may be a fine ceramic powder such as alumina, zirconia, silicon nitride, silicon carbide, etc., in addition to a conventionally known mixture of a clay material, quartz and feldspar. Also, a plurality of mixtures or solid solutions of the above-described substances can be applied. Further, various metals and metal powders can be used.

As the burnt material for obtaining the pores in the tile, conventionally known wood chips, quartz powder, coke powder, and plastic powders such as foamed polyethylene (foamed) are used. These burned materials usually have a specific gravity of about 0.1 to 0.02, and can be used if the specific gravity difference from the ceramic slurry is 0.1 or more.

When it is desired to add a self-curing agent to other additives for making the ceramic powder into a slurry, epoxy resin, polyester resin, phenol resin, melamine resin, polyimide resin, cyanate ester are used as binders to be thermally cured. Resins, diallyl phthalate resin, silicone resin, isocyanate resin, and modified resins thereof. Emulsions of these resins are also used. And as a thing with thermogel properties,
There are proteins and starch. As a binder having water setting, there is alumina cement. As the solvent, a mixture of an aromatic solvent and an aliphatic solvent may be used for the thermosetting resin, and an ester or ketone-based solvent may be added. Water may be used as a solvent for emulsions, proteins, starches and the like, and a surfactant for improving the wetting and dispersion of the ceramic, and a thickener for adjusting the viscosity or fluidity may be used.

When the ceramic slurry does not have self-hardening properties, a thickener for adjusting viscosity or fluidity,
If necessary, a surfactant for improving the wetting and dispersion of the ceramic powder is added to adjust the viscosity to a predetermined value.

Slurry viscosity was measured at 25 ° C using a BM type viscometer at 60 rpm.
Measured in When the slurry viscosity is 1000 cps or more, the ceramic powder and the solvent in the slurry undergo precipitation and separation, and the fired material floats in the solvent.

On the other hand, if it is 10,000 cps or more, it is difficult to separate the burnt material, and it is difficult to obtain a tile having a dense surface. In addition to the viscosity, the thixotropy of the slurry is preferably 1 or less, and if it is 1 or more, the thixotropy becomes strong and uneven distribution of the burnout material hardly occurs. This thixotropy is measured at 60 rpm and 6 rp
m.

The time from placing the slurry in the mold during molding to the start of dehydration during hardening or casting is equivalent to the time required for the burnt material in the slurry to separate, but this time depends on the viscosity of the ceramic slurry, the thixotropy coefficient, It is determined by the specific gravity difference between the burned material and the ceramic slurry containing no burned material. According to the experiment, the viscosity was 4,000 cps, the thixotropy coefficient was 0.90, the specific gravity difference was 1.4 at 300 seconds, and similarly, 2,000 cps,
It was 430 seconds at 0.95 and 1.2.

A molded product that does not have the size of the final product at the time of molding can be formed into a product by a known firing method after having a desired size. Incidentally, if the formed body is dried and glazed before firing, it is possible to form a glazed product.

(Operation) In the present invention, the specific gravity difference between the ceramic slurry and the burnt material is used, and the slurry is adjusted and shaped so that the specific gravity difference appears as a shape. The separation of the burnt material due to the difference in specific gravity is an action due to the buoyancy of the burnt material.

(Example) Example 1 First, production of a ceramic tile using a self-curing composition will be described. The following formulation was prepared as a ceramic slurry.

Water 150 parts by weight Dispersant 8 parts by weight Thickener 0.5 parts by weight Epoxy resin 30 parts by weight Self-emulsifying polyamide resin 6 parts by weight 99.9% alumina 800 parts by weight After treating the above mixture with a ball mill for 24 hours, the above composition 100 0.5 parts by weight of expanded polystyrene beads were added to the parts by weight and mixed gently. At this time, the specific gravity of the slurry before adding the beads was 2.5, and the specific gravity of the beads was 0.04.
The viscosity after mixing the beads was 3,450 cps at 25 ° C., and the thixotropy was 0.98. The slurry in which the beads were mixed (slurry containing a fired material) was placed in a stainless steel plate-shaped mold, allowed to stand for 300 seconds, heated at 80 ° C. for 20 minutes, molded, disassembled, and taken out. Molded body is 1,50
A ceramic tile was obtained by firing at 0 ° C. for 10 hours. The surface of this tile is dense and the apparent specific gravity is 1.5
Met. This tile was tested for crack resistance, abrasion resistance, bending strength, frost damage resistance, and chemical resistance according to JIS A5209 (Standard for ceramic tiles) for exterior tiles, but there were no problems.

In the comparative example, the composition for preparing the ceramic slurry was as follows.

Water 200 parts by weight Dispersant 10 parts by weight Thickener 1 part by weight Epoxy resin 40 parts by weight Self-emulsifying polyamide resin 8 parts by weight 99.9% alumina 800 parts by weight For the above mixture, the ratio of 100: 0.5 as in the example. The slurry containing the burnt material added with and blended with expanded polystyrene beads was 800 cps at 25 ° C. and the thixotropic coefficient was 0.8. Subsequent molding and firing were performed in the same manner as in the previous example to obtain a molded body and a sintered body. When the slurry containing burnt material having a low viscosity was used, the surface was dense but burnt marks were concentrated on the back surface, and the back surface strength was almost nil.

Next, as Comparative Example 2, the ceramic slurry and the burnt material-containing slurry were prepared with the ratio of water and the thickener of the above Comparative Example being 250 parts by weight and 2 parts by weight. The physical properties of the slurry containing the burnt material were 25 ° C., 600 cps, and the thixotropic coefficient was 0.7.
Subsequent operations were performed in the same manner as in the previous example to obtain a molded body and a sintered body. When the slurry containing burnt material having a low viscosity was used, a sintered body having burnout scars could not be obtained due to separation of the ceramic powder.

In Comparative Example 3, the ceramic slurry in Example 1 was used.
To 100 parts by weight, 0.08 parts by weight of foamed polystyrene beads as the burnout material were mixed to obtain a slurry containing the burnout material. This mixture is 1: 0.05 in volume ratio. After that,
A sintered body was obtained in the same manner as in Example 1. Although the surface of the sintered body was dense, the specific gravity of the obtained tile was 2.3.

In Comparative Example 4, the ceramic slurry of Example 1 was used.
To 100 parts by weight, 1.0 parts by weight of foamed polyethylene beads as a burnout material were mixed at a volume ratio of 1: 0.6 to obtain a slurry containing burnt material. The subsequent operation was performed in the same manner as in Example 1 to obtain a sintered body. The surface of the sintered body was dense, and the specific gravity of the obtained tile was 0.7.
There was too much a density difference between the tile front surface and the back surface, and some warped or cracked during sintering. As Example 2, a ceramic slurry was prepared with the following composition. (Hydraulic self-cured product) Water 50 parts by weight Dispersant 4 parts by weight Kaolin 27 parts by weight Clay 29 parts by weight Silica sand 33 parts by weight Feldspar 11 parts by weight After treating the above mixture with a ball mill for 24 hours,
To 100 parts by weight of the above composition, 2 parts by weight of expanded polyethylene beads (commonly known as PEF) were added, mixed lightly, and then molded in the same manner as in the previous example to obtain a sintered body. The physical properties of the slurry containing the burnt material were 2,400 cps at 25 ° C and a thixotropy coefficient of 0.24.

In Example 3, a molded body was obtained by cast molding using the slurry containing burnt material shown below. An aqueous solution of polyvinyl alcohol was previously applied to the inner surface of the gypsum mold to temporarily limit the mold from absorbing water in the ceramic slurry.

35 parts by weight of water 6 parts by weight of dispersant 50 parts by weight of alumina 50 parts by weight of kaolin 1 part by weight of burnout material (foamed styrene) The molded body was removed from the mold, dried and fired to form a ceramic tile. The surface of this tile was dense and the apparent specific gravity was 0.75. Crack resistance of this tile,
The abrasion resistance, bending strength, frost damage resistance, and chemical resistance were tested in the same manner as in Example 1, but there were no problems.

In Example 4, a molded product was obtained by using the vibration casting method. At this time, the composition of the slurry was as follows, and its thixotropy was 0.9.

120 parts by weight of water 20 parts by weight of dispersant 600 parts by weight of 99.9% alumina 4 parts by weight of burnt-out material (styrene foam) After molding, calcination is performed in the same manner as in Example 3,
A ceramic tile was obtained. The tile surface was dense and the apparent specific gravity was 1.5. The physical properties of the tile were the same as in Example 1, but there were no problems.

(Effects) According to the present invention, the ceramic tiles can be reduced in weight regardless of the interior and exterior, and the surface can be made as dense as conventional tiles. For this reason, the surface strength is lost due to the porosity, and the surface is not easily damaged. Even when pores appear due to porosity on the back side, the performance as a tile is sufficient, and no problem occurs. As a result, not only the saving of the raw material of the tile itself, but also the effect of saving the structural members of the building by reducing the weight of the tile can be obtained. Further, even when tiles having the same weight are separately used, a more luxurious finish can be obtained.

Claims (6)

(57) [Claims] In a tile lightened by including burnout holes, a portion having many burnout holes and a portion having almost no burnout holes are sequentially changed in the thickness direction in one tile, and are present in an inclined manner. Lightweight ceramic tiles characterized by: 2. A ceramic slurry having a self-curing property such as thermosetting, thermogelling or water-curing and containing a burned material in a volume ratio of 1/10 to 1/2 at a viscosity of 1,000 cps to 10,000 cps (25 cps).
Temperature, BM type viscometer, 60rpm), put in the mold, allow time for separation of burnt material, harden or gel to form molded body, and then burn and burn Manufacturing method of ceramic tile. 3. A ceramic molded body is formed by casting a water-soluble substance at an interface between a mold and a ceramic slurry by using a casting method, and then casting a ceramic slurry containing a burnt material into the mold. 3. The method for manufacturing a lightweight ceramic tile according to claim 2, wherein: 4. The method for producing a lightweight ceramic tile according to claim 2, wherein the apparent specific gravity difference between the burned material and the ceramic slurry containing no burned material is 0.1 or more. 5. The lightweight ceramic tile according to claim 2, wherein the ceramic molded body is produced by a vibration casting method, wherein the ceramic slurry used has a thixotropic coefficient of 1 or less. Production method. 6. The method for producing a lightweight ceramic tile according to claim 2, wherein the apparent specific gravity difference between the burned material and the ceramic slurry containing no burned material is 0.05 or more.