JPS5879838A - Production of silver-glazed roof tile free from cracking and color changing - Google Patents

Abstract

PURPOSE:A lead-containing glaze that contains in specific proportions Na2O, K2O, Al2O3, SiO2, MnO, and PbO respectively is used to effect oxidative calcination of roof tile base in a tunnel kiln and produce silver-glazed roof tiles from color changing and cracking. CONSTITUTION:According to the Seger expression, a lead-containing glaze composition is prepared by using less than 0.025mol of totaling Na2O and K2O among alkali metal compounds, more than 0.1mol of Al2O3 among neutral components, more than 1.2mol of SiO2 among acidic components and 0.6mol of MnO as a divalent metal oxide. At this time, the molar ratio of SiO2/Al2O3 are set to 32-4 as an essential condition. Then, a lead-containing flint, siliceous sand, kaolin and bentonite containing CMC are crushed by means of a wet ball mill. Then, dried tile base is coated with the above lead-containing glaze and oxidatively calcined in a tunnel kiln of 1050-1100 deg.C to produce silver-glazed roof tiles free from color changing and cracking.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to producing penetrating and non-tarnishing silver glaze roof tiles.

As is well known, large quantities of silver sleeve roof tiles are produced by oxidation firing at temperatures before and after 1080℃ in tunnel kilns. Currently, it has the disadvantage that it collects dust, so it must be stored in a warehouse or the like.

There are five conventional glaze compositions, including Nano, K2O, and CuO.
The number of moles of AlB is large, or AlB12.810. In both cases, discoloration and penetration could not be avoided due to the small amount.

This is the result of intensive research to eliminate these shortcomings.

This has succeeded in rectifying the above drawbacks.

That is, the present invention aims to prevent discoloration and penetration of the above-mentioned silver sleeve tiles.

The method basically limits the alkaline components in the glaze and mainly uses lead compounds as a fluxing agent.

8102, the content of Al2O3 is increased, and at the same time, a manganese compound is mainly used as a metal oxide.

This reduces the coefficient of thermal expansion of the glaze.

The present invention is characterized by suppressing penetration and preventing discoloration unlike conventional methods.

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

However, research has revealed that depending on the firing conditions, glazes that contain copper compounds among metal compounds have a lower acid resistance due to the elution of copper, making them unavoidable.

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 Segel representation. SaraKFe203NiO, Co
By adding a total of 0.01 to 0.1 mole of one or more metal compounds such as MoolWO and MoolWO, the silver color becomes even stronger.

At the point of penetration and regrowth, the 5th Nano of alkali metal compounds
In addition, the total amount of 0.025 mol or less of 0.025 mol or less in Segel representation of
The setting of 1 mol or more and 1.2 mol or more is a necessary condition in order to bring the thermal expansion of the glaze closer to that of the tile base and prevent the occurrence of penetration.

That is, alkali metal compounds such as Nano, K2O, etc. are generally necessary as components of low-temperature glazes and are useful as necessary fluxing agents, but they themselves do not have a negative effect on penetration. There is.

As a result of research, the number of moles of Nano and K2O was reduced.

It has been clarified that keeping the total amount Q,025 mol or less is a major factor.

It has become clear through research from the point of view of thermal expansion that 810g requires 1.2 mol or more and Al2O3 0.1 mol or more.
In particular, when the number of moles of 1.03 was small, the silver color was good immediately after firing, and the appearance was excellent in clarity, but as a result of observation over time, the occurrence of penetration could not be avoided.

It has thus been found 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 8102/A1103 is 32 to 4
This is also derived from the above-mentioned penetration prevention aspect, and by having the ratio of 8tog/Al$103 within this range, a so-called eutectic phenomenon occurs, and the number of moles of the component that becomes the solvent in the glaze is reduced. This is necessary to reduce the expansion coefficient.

From the above, the method of obtaining a non-penetrating, non-discoloring silver sleeve tile according to the present invention includes, for example, leaded frit 18-38 parts silica sand 5-20 kaolin 15-25 manganese 25-35 zircon silicate 6-15 rutile 6-15 lime borate Add 0.5 parts of bentonite and 5 parts of CM CQ to the mixture of 0 to 10, grind it in a wet mill, and apply it to the dry tile base.
Glaze to a coating weight of 0 to 1009, 1050°
When oxidized and fired at ~1110°C without a tunnel, a penetrating silver glazed tile without discoloration can be obtained.

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

Example 1 Using raw materials of lead silicate, colemanite, and silica sand.

Mix the powdered mixture according to Segel's formula uniformly and heat it to 1300℃~1650℃.
The leaded frit was obtained by melting at ℃ and quenching it.

Next, we used this leaded frit, kaolin, silica sand, manganese dioxide, zircon silicate, and rutile ore to weigh 810g in Segel scale. 6.14 /Al103 /Al103 mixture was prepared, 0.5 parts of K CM C and 0.5 parts of bentonite were added thereto, wet pulverized and mixed, and the resulting slip was applied to the tile base in an amount of 95 g per cross tile. Glazed with
It was oxidized and fired in a tunnel kiln at a maximum temperature of 1080°C for 22 hours to obtain a beautiful silver sleeve tile.

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

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

Example 2 Using lead silicate, silica sand, kaolin, manganese dioxide, zircon silicate, rutile, and lime borate, a circular compound of 81031/, 6, s 2, A1g03 in Seegel representation was prepared, and C! Add 5 parts of M CQ and 0.5 parts of bentonite and wet mix and crush. The resulting slip was glazed onto a tile base with a coating weight of 90 g per tile, and oxidized and fired in a tunnel kiln at a maximum temperature of 1090°C for 19 hours. I got a good silver sleeve tile.

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

Example 3 Using lead silicate, silica sand, kaolin, barium carbonate, zirconate fI, rutile ore, manganese dioxide, and boric acid current, a ring compound of ""/-6,00 1i05 in Seegel representation was prepared, and this 0.5 parts bentonite.

Add 5 parts of CMGO and mix by wet pulverization, and apply the obtained slip to the tile base in an amount of 100 g of soft white per tile.

The tiles were glazed and fired in a tunnel kiln at a maximum temperature of 1080°C for 24 hours to obtain a good silver sleeve tile with a slightly blackish tint. Similar to Examples 1 and 2, no discoloration penetration number 1 was observed in this roof tile.

Agent Akira Asamura 4 other people

Claims (1)

[Claims] lia, O, K, O, Mul, 03.810g, Mn
It is a leaded glaze whose main components are O, PBO, and contains less than 0.025 mol of alkali metal compounds, NagO and 3O, according to the Segel representation of the glaze, and contains 0.025 mole or less of human 1303 as a neutral component. 1 mole or more, 8 as acidic component
182 mol or more of 101I, M as a divalent metal oxide
Contains 0.6 mol or more of nO, and 8102/AlB
1. A method for manufacturing a silver sleeve tile, which comprises using a leaded glaze having a molar ratio of 12 to 4 and oxidizing the glaze in a tunnel kiln at 1050 to 1110°C.