JP2008133153A - Porous ceramics with moisture permeable glaze applied thereto - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide porous ceramics whose colors, gloss and fixability are excellent while maintaining moisture absorption properties and moisture release properties, by applying a moisture permeable glaze thereto, though, when a glaze is applied to a moisture conditioning ceramics, moisture permeating speed is remarkably reduced. <P>SOLUTION: Low melting point frit is blended with pigment and an inorganic substance, particularly, a porous raw material, so as to be a glaze. A porous surface is coated with the glaze into a prescribed thickness, and firing is performed so as to obtain a moisture permeable glaze whose colors, gloss and fixability are excellent. Thus, humidity conditioning building materials and porous ceramic-applied products having excellent design properties can be obtained. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a glaze applied to the surface of a porous ceramic such as a humidity-controlling ceramic product, and provides a moisture-permeable glaze that has appropriate moisture permeability and is excellent in color, gloss, and adhesion.

Porous ceramic products are, for example, humidity control ceramics created by mixing, forming, and firing, using diatomaceous earth as the main raw material and other ceramic raw materials. For example, humidity control using Wakkanai layer diatomaceous earth Some are described in functional materials, humidity control building materials, etc.
Japanese Patent No. 2652593 Japanese Patent No. 3659867 Patent Publication No. 8-144387 Patent No. 3519004

Glaze is applied to color ceramics, improve strength, and obtain surface smoothness, but generally forms a glassy film on the surface of the ceramic product by firing and does not have moisture permeability or water permeability. Therefore, the moisture permeability of the porous ceramic is lost. Humidity control building materials have been proposed to remedy these drawbacks, but the glazes proposed here are not moisture permeable, so they are applied to 90% or less of the product surface. The moisture permeability was obtained from the non-existing part. Therefore, the original moisture permeability of ceramics cannot be expressed.

The present invention provides a glaze that makes the glaze itself moisture-permeable and has excellent color, gloss, and adhesion to the ceramic surface.

According to the present invention, an inorganic material such as pigment, clay, aggregate, porous material, and frit are blended in a predetermined ratio, and the glaze having a predetermined thickness is applied to the porous ceramic. . The type of pigment depends on the desired color of the porous ceramic product, for example, zircon gray gray; praseodymium yellow, chrome titanium yellow (above yellow); chrome green, Victoria green (above green); bitumen, turquoise blue (above blue) ); Chrome tin pink, salmon pink (more pink). Most of the porous ceramics are fired at 900 ° C. or less. Since these pigments do not melt at such temperatures, the frit melts into a glass phase when fired, and pigment particles that do not melt into the glass phase are dispersed. Exists in form. When the blending amount of the pigment and the inorganic substance increases, the glass phase melts with each other and hardly forms a matrix and has moisture permeability, and when it further increases, the glaze cannot be fixed. The present invention has moisture permeability to the frit by appropriately blending a pigment and an inorganic substance, particularly a porous material, into the glaze and appropriately adjusting the thickness (glazing) of the glaze, In addition, it was possible to create a moisture-permeable glaze with excellent color, gloss, and adhesion.

The moisture-permeable glaze of the present invention can be applied to porous ceramics, in particular, porous ceramics excellent in color, gloss, and adhesion, particularly humidity-controlling ceramics, without significantly reducing the moisture permeability of porous ceramics. Made possible. Humidity-controlling ceramics are used as exterior materials and interior materials, and it is possible to control the humidity in the house and prevent the formation of condensation to prevent condensation, and it is expected to have the effect of preventing indoor overdrying and overwetting. By making it possible to apply colored glazes with moisture permeability, it becomes a building material with excellent design and further expands its application, greatly contributing to the industry.

The present invention adjusts the blending amount of inorganic substances such as pigments, aggregates, and porous raw materials with respect to the frit, and adjusts the thickness to provide moisture permeability and excellent color, gloss, and adhesiveness. It is an object of the present invention to provide a humidity control ceramic having an excellent design without obtaining a glaze and reducing the humidity control performance of the porous ceramic. The frit to be used needs to be sufficiently melted at the temperature at which the porous ceramic is fired, and it is necessary that the coefficient of thermal expansion and water resistance are excellent. The pigment can be a commercially available inorganic pigment, or a simple inorganic substance such as iron oxide, chromium oxide, nickel oxide, zirconia, titania, tin oxide, or zirconite. As the porous raw material, diatomaceous earth, zeolite, allophane, opaline silica, smectite and the like can be used.

The humidity control function of the porous ceramics is expressed by moisture absorption / release capacity and its speed. The moisture absorbing / releasing function is governed by the type of porous material, its blending amount, the firing temperature, and the like. The moisture absorption / release rate varies depending on the moisture permeability of the glaze applied to the porous ceramic. It is desirable that the moisture absorption / release rate is not significantly reduced by applying glaze. For example, 85% by weight of Wakkanai diatomaceous earth and 15% by weight of giroirome clay, cast-molded, and fired at 800 ° C., the humidity control ceramic is JIS A 1470-1 humidity control building material Based on the humidity test method, measuring the moisture absorption amount in a medium humidity region (relative humidity 75% and 53%) with a flat plate sample of 100 × 100 × 10 mm, the moisture absorption amount is 96 g / m ² , moisture release The amount was 77 g / m ² . The moisture absorption gradient and the moisture distribution gradient were 19 g / (m ² · h) and 15 / (m ² · h) in the first hour.

On the other hand, porous ceramics obtained by applying a glaze with an appropriately adjusted blending ratio of pigment, inorganic substance, and frit to a predetermined thickness and firing are used for moisture absorption, moisture release, moisture absorption gradient, moisture release. There was no significant difference between the gradient ceramic and the unglazed porous ceramic, and a porous ceramic with good hue and gloss was obtained. In addition, a humidified vase produced by applying a similar glaze to the surface of a vase molded with porous ceramics, the water in the vase oozes out through the ceramic wall, and is about the same as a humidified vase Evaporated from the surface at an evaporation rate of 1, and showed good humidification characteristics as a moistened vase.

When the thickness after firing is 50 μm or less, the molten glaze cannot cover the entire surface of the porous ceramic, and thus exhibits moisture permeability, but color unevenness is likely to occur due to variations in the thickness. Generally, it is preferable to adjust the thickness to 50 to 200 μ after firing, which corresponds to about 70 to 300 μ in the thickness before firing. By glazing with such a thickness, it is possible to obtain a glaze having a good molten state after firing and little variation in color and gloss. However, depending on the composition of the glaze, the glaze may be in a molten state with a thickness of 50 μm or more, and sufficient moisture permeability may not be obtained.

On the other hand, by blending pigments and inorganic substances, especially porous raw materials, with a low melting point frit, a blending composition of glaze that is moisture permeable and has excellent color and luster even when the thickness is 50 μm or more. I found it. Since the pigment is blended for coloring, it is blended by several percent with respect to the glaze. By blending 10% or more and 60% or less of an inorganic substance together with this pigment, a glaze having moisture permeability and excellent color and gloss can be obtained even if the thickness is 50 μ to 200 μ. . Furthermore, when the inorganic substance is a porous raw material such as diatomaceous earth, zeolite, allophane, opaline silica, and smectite, moisture permeability can be easily obtained with a small amount of blending, and the surface smoothness and gloss are excellent. Inorganic substances that are not porous raw materials correspond to fillers (aggregates) such as titania, silica sand, zirconite, tin oxide, and clays. These are blended for adjusting light transmittance, adjusting the thermal expansion coefficient of the glaze, and adjusting the viscosity of the glaze slurry.

The reason why the total of the pigment and the inorganic substance is 10% or more is that when it is less than 10%, the range of the thickness where moisture permeability can be obtained is 50 μm or less, and a glaze with little variation in color, gloss, etc. can be obtained. This is because there is not. The reason why it is 60% or less is that when it exceeds 60%, the glaze is not sufficiently melted, and the glaze is not sufficiently fixed to the porous ceramics.

The reason why the porous raw material in the glaze is 20% by weight or more is that by blending the porous raw material by 20% by weight or more, even if the thickness after firing is 100 μm or more, good moisture permeability is exhibited. The reason why it is 60% by weight or less is that when it exceeds 60%, the molten state of the glaze is deteriorated and the fixing property is deteriorated.

As for the frit, low melting point boric acid type frit CY5600M3 (deflection point 545 ° C) manufactured by Takara Standard Co., Ltd., as a pigment, reagent grade 1 iron oxide manufactured by Kanto Chemical Co., Ltd., Takara Standard Co., Ltd. zirconite as an inorganic substance, and porous raw material. Mitsui Chemicals, Inc. Bind Serum WA310 was used as a binder with diatomaceous earth manufactured by Sirix Corporation. The raw materials are weighed to the blending ratio (% by weight) shown in Table 1, 300 g of alumina cobblestone having a diameter of 6 mm is put into a 500 ml plastic container, the moisture is 40%, and the binder is 3% (outside distribution) with respect to the solid content. It adjusted so that it might become. Porous ceramics weighed 3 kg of 85% by weight of Silix Co., Ltd. diatomaceous earth and 15% by weight of Marusen Pottery Raw Materials Co., Ltd., and placed 3 kg of alumina cobblestone in a 5 l plastic container, resulting in a moisture content of 35%. The slurry was prepared as described above, cast into a plaster mold, and dried to prepare a 120 × 120 × 12 mm plate. On one side of the porous plate, the glaze prepared in the ratio shown in Table 1 was spray-coated so as to have a predetermined thickness. These samples were fired in an electric furnace at a temperature of 100 ° C./hour, held at 800 ° C. for 1 hour, and then allowed to cool. These samples were adjusted based on the moisture absorption and desorption test method for JISA1470-1 humidity control building materials, and the moisture absorption rate, moisture absorption rate, moisture release rate, and moisture release rate were measured. The results are shown in Table 1.
Table 1

From the result shown in Table 1, the sample which applied the glaze based on this invention with respect to the sample which is not glazed obtained the favorable moisture absorption characteristic and the moisture release characteristic. Sample No. 9 with a small amount of pigments and inorganic substances carried out as a comparison has good glaze color, luster, and adhesion, but has significantly reduced moisture absorption and moisture release characteristics compared to the unglazed sample. I understand that. Similarly, No. 10 with a small cocoon thickness has good moisture absorption and moisture release characteristics, but the color is thin, and there is a difference in color intensity depending on the location (thickness), which appears to be uneven and is not preferable. .

The same slurry for porous ceramics as in Example 1 was prepared, the slurry was cast into a gypsum mold of a vase, drained after 1 hour, dried after mold release, and described as No. 3 sample in Example 1 on the surface. The glaze was sprayed by a spray method, aiming at a thickness of 0.20 mm before firing, and firing was performed at a maximum temperature of 800 ° C. in an electric furnace. The fired vase had a height of 180 mm, a barrel diameter of 135 m, and the average thickness of the porous ceramic ceramics was about 7 mm. This can contain about 1400 g of water. The vase was evenly glazed and slightly glossy. Water was added to this sample and the moisture release rate was measured in an atmosphere with a relative humidity of 35% and an air temperature of 31 degrees. The result was 480 g / day, which was not different from the 492 g / day vase baked without fire. Met.

Claims (3)

It is a porous ceramic with glaze applied, the thickness of the glaze after firing is not less than 50 microns and not more than 300μ, and the moisture release amount of the porous ceramics applied to the entire surface of the product is not less than 80 g / m ² Porous ceramics characterized by being. 2. The porous material according to claim 1, wherein a glaze having a composition of 10% by weight to 60% by weight of inorganic material such as pigment, clay, aggregate, and porous raw material and a low melting point frit of 40% to 90% is applied. Ceramics. The porous ceramic according to claim 1 or 2, wherein the porous raw material is applied with a glaze having a composition of 20 wt% or more and 60 wt% or less.