JPS6049143B2 - Method for manufacturing non-penetrating and non-tarnishing silver glaze tiles - Google Patents

Description

[Detailed description of the invention] O, O~0.08Na O, 10~O, 31Ca o, oo-O, 12Mt o, 11 ~ O, 15 Pb O, 2 3 ~ O, 7 O Mn O, 0 0 ~ 0.15 Cu O, 00-O, 05Zn K2O) CUO's model There are things like Na2O Is the amount of 102 small? If the number of files is too large, A1.

O. can avoid the occurrence of It gets wet and discolored. Nakatsuta.

As a result of intensive research in order to eliminate such drawbacks, the above-mentioned drawbacks were successfully improved.The present invention relates to manufacturing a silver glaze roof tile that is free from penetration and discoloration.

As is well known, silver glazed tiles are produced in large quantities in tunnel kilns by oxidation firing at around 1080 degrees Celsius, but due to discoloration over time and the occurrence of intrusions, dust gets into the intrusions during piling. Currently, it has the disadvantage of being stored in a warehouse or the like.

The glaze composition is conventional. 5Aι203 0.95-1.335iO2 0, O80.14ZO2 0.26-0.28TiO2 O, 00-O, 17B2O3 0,OO~0.05P205 Ru.

That is, the present invention aims at preventing discoloration and penetration of the above-mentioned silver glazed tiles.

The method basically limits the alkaline component in the glaze, mainly uses lead compounds as a flux, and
At the same time as increasing the content of 2O3, a manganese compound is mainly used as the metal oxide.

A feature of the present invention is that this reduces the coefficient of thermal expansion of the glaze, suppresses penetration as in conventional cases, and prevents discoloration.

To explain the discoloration surface in detail, it is well known that adding a metal compound to a glaze until it is saturated creates a metal-like Mann glaze, and conventional silver-glazed roof tiles also apply this principle.

However, research has revealed that depending on the firing conditions, glazes containing copper compounds, among other metal compounds, have reduced acid resistance due to the elution of copper and cannot avoid discoloration. Therefore, in the present invention, the copper compound in the glaze is suppressed as much as possible, and the glaze is mainly composed of a manganese compound, which contains 0.6 mole or more in Seegel expression.

When the MnO content is less than 0.6 mol, no silver color is developed, but only a dark brown color or a black metallic luster is exhibited. Furthermore, Fe2O3, NiO. ．． COO. ．． MOO. ．． W.O.
The total amount of one or more metal compounds is 0.01 to 0.0.
By adding 1 mole of it, the silver color becomes even stronger.

In terms of penetration, Na2 is particularly important among alkali metal compounds.
The reason why O and K2O are set to a total of 0 mol to 0.025 mol or less on the Segel scale, and Al2O3 and SiO2 are set to 0.1 mol or more and 1.2 mol or more, respectively, is to adjust the thermal expansion of the glaze to that of the tile base. This is a necessary condition to prevent penetration from occurring.

That is, Na2O. ．． Alkali metal compounds such as K2O are generally necessary components of low-temperature glazes and are useful as necessary fluxing agents, but they themselves have a negative effect on penetration. Research results Na2O
．． ．． It has been clarified that a major factor is to reduce the number of moles of K2O, so that it is not included, or even if it is included, the total amount is 0.025 mole or less. It has become clear through research from the perspective of thermal expansion that SjO2 and Al2O3 are required to be at least 1.2 moles and at least 0.1 mole, respectively. When the number of moles of O3 was small, the silver color was good immediately after firing, and the appearance was excellent in sharpness, but as a result of observation over time, the occurrence of penetration could not be avoided.

It is known that penetration cannot be sufficiently prevented even if the number of moles of either one of the two is less than this.

In addition, the component molar ratio of SlO2/Al2O3 is 6 to 6.52.
This is also derived from the above-mentioned penetration prevention aspect, and SiO2/Al.

When the O3 ratio is within this range, a so-called eutectic phenomenon occurs, which is necessary to suppress the number of moles of the component that becomes a melt in the glaze and to reduce the expansion coefficient. From the above, the method for obtaining the non-penetrating, non-tarnishing silver glazed tile of the present invention is as follows: 0.5 part of bentonite, CMCO.5
10% of the glaze was applied to the dried tile base to give a coating weight of 90 to 100y per tile.
When oxidized and fired in a 500~11100 tunnel kiln, a penetrating silver glazed tile with no discoloration can be obtained.

Next, the present invention will be explained in more detail by giving examples.

Example 1 A powdery mixture of 0.66Pb01.43Si020.3 4Ca00.4嘱03 in Segel representation was uniformly mixed using raw materials of lead silicate, colemanite, and silica sand, and heated at 1300°C to 1350°C.
A leaded frit was obtained by melting at .degree. C. and quenching it.

Next, using this leaded frit, kaolin, silica sand, manganese dioxide, zircon silicate, and rutile ore, a glaze mixture according to the Seegel expression was prepared, and this was coated with CMCO. 5 parts of bentonite and 0.5 parts of bentonite were mixed by wet grinding, and the resulting slip was glazed on the tile base with a coating weight of 95 da per tile, and then oxidized and fired in a tunnel kiln at a maximum temperature of 1080°C for 2 hours. A good silver glazed tile was obtained.

This tile was immersed in 1N hydrochloric acid, and as a result of observing the glazed surface, no discoloration was observed.

Furthermore, no penetration or discoloration was observed in a treatment test conducted in an autoclave at 5 atm for 1 hour.

Example 2 Using lead silicate, silica sand, kaolin, manganese dioxide, zirconium silicate, rutile, and lime borate, LlV2ll book A2V3 completed-υ. Create a glaze mixture of υmu and apply CMCO. 5 parts of bentonite and 0.5 parts of bentonite were added and wet mixed and crushed, and the resulting slip was glazed onto a tile base with a coating weight of 90 f per tile, and then oxidized and fired in a tunnel kiln at a maximum temperature of 1090°C, East Time to give a good silver color. Obtained glazed tiles.

Similar to Example 1, this roof tile also had no discoloration due to acid, penetration due to autoclaving, discoloration, etc.

Example 3 A glaze mixture of 0.5 part by bentonite and
CMCO. 5 parts were added and mixed by wet grinding, and the resulting slip was glazed onto a tile base with a coating weight of 100y per tile, and then oxidized and fired in a tunnel kiln at a maximum temperature of 1080℃ for 2 batches to produce a good, slightly blackish color. I got a silver glazed tile.

Claims (1)

[Claims] 1 In the Seegel representation, when R^1 and R^2 are alkali metals and alkaline earth metals, respectively, it has the composition ▲There are mathematical formulas, chemical formulas, tables, etc.▼, and SiO_2/ A method for producing a silver glazed tile, which comprises using a leaded glaze having an Al_2O_3 ratio of 6 to 6.52, and oxidizing the glaze in a tunnel kiln at a temperature of 1050 to 1110°C.