JPS6325258A - Manufacture of low temperature burnt ceramic - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a method for producing low-temperature fired porcelain.
Due to the low temperature of 200℃, it has good translucency and has almost the same strength as ordinary porcelain, and even though it is fired at a low temperature,
The temperature range from when the fired porcelain becomes transparent until it undergoes thermal deformation is set to a practical temperature that is suitable for temperature control in firing R&G.

(Prior art) In general, it is said that porcelain products used for tableware etc. are high-grade porcelains that have a higher porcelain-forming temperature, which exhibits the light transmittance unique to porcelain, and are stronger.
℃ or higher. Bone china, which is also called soft porcelain, is usually fired at about 1250°C.

On the other hand, the same main raw materials as in the present invention, ■synthetic minerals mainly composed of protoenstatite, ■talcite, ■silica stone, ■
Porcelain fired from a base made by mixing and molding a clay material such as kaolin is known, but it contains 50% ■, 15% ■,
The firing temperature of the base material with 5% ■ and 30% ■ is the maximum temperature of 1320℃, and the transparency of the porcelain product fired for 36 hours is 2 in thickness.
．． 8111+a 1.52%, bending strength 1500Kg/
c+112, and the temperature range from the porcelain-forming temperature at which the base material becomes translucent to the time at which it sag and deform due to thermal softening is small, making temperature control in the firing kiln extremely delicate.

In other words, even if the firing mold can determine the porcelain temperature using a temperature sensor, and then immediately control the leveling temperature, there are some parts of the firing mold itself that cannot be brought to the controlled temperature, and it is impossible to prevent thermal changes in the base material in those parts. Because you can't.

For this reason, it is desirable that the temperature range between the porcelain forming temperature at which the base material becomes translucent and the heat change temperature be as large as 40 to 50°C.

In addition, in the production of porcelain, it is possible to fire at low temperatures, and in this case, in addition to alkali and alkaline earth,
A raw material containing glass is blended into the porcelain raw material as a flux, and the fired porcelain base becomes porcelain at low temperatures and becomes translucent and loses its water absorption properties. Because it produces components, its strength is low and it is not possible to manufacture high-quality products.

(Problem to be solved by the invention) Conventional porcelain! Ii! Despite the state of the art mentioned in the previous section, the problem of providing porcelain with high strength at low temperatures has not yet been solved. The purpose of the solution is to make it as good as porcelain and to be able to sufficiently maintain the temperature range mentioned above.

(Means for Solving the Problems) The present invention relates to a method for achieving the object stated in the previous section, and includes a synthetic mineral whose main component is protoenstatite, which is produced by mixing silica stone and magnesium hydroxide with magnesium carbonate and calcining the mixture. 30 to 70% of talc or a mixture thereof, 1 to 30% of silica, 1 to 20% of feldspar, 1 to 10% of limestone, wollastonite or calcium phosphate as a calcium-containing raw material, in a smaller amount than the above-mentioned feldspar; The present invention relates to a method for producing low-temperature fired porcelain, which is characterized in that a base formed by blending clays 25 to 4596 is fired at 1100 to 1200°C.

In the present invention, the amount of feldspar added is set to 1 to 2096, which is higher than the amount of calcium-containing raw material added, because adding feldspar alone does not have a sufficient effect of lowering the firing temperature to 1200°C or less, and adding 20% or more is necessary. Even if the firing temperature is lowered, the effect of lowering the firing temperature will not improve much, or the amount of other raw materials will be reduced, so that it will not have negative effects such as poor plasticity or lowering the strength of fired porcelain products. It is. It is preferable to add the calcium-containing raw material in an amount according to the above-mentioned conditions, but if only the calcium raw material is added alone or in excess, the firing temperature range will be narrowed.

A preferred embodiment of the invention will now be described.

(Examples) O Example 1 A mixed pulverized product containing 50% by weight of silica stone and 50% by weight of magnesium hydroxide is calcined at 1350° C. for 40 hours to obtain a synthetic mineral mainly composed of protoenstatite.

The composition of the above mixed pulverized product was as follows.

The raw materials for the porcelain base were mixed as follows.

Synthetic minerals mainly composed of protoenstatite 50% Silica stone 5% Long stone 10% Wollastonite 5% Kaolin 30% Add an appropriate amount of water to this mixed raw material, knead and mold, and dry the molded product at the highest temperature It was fired for 24 hours in a tunnel kiln controlled at 1160°C.

The light transmittance of this porcelain product is 1.44% at a thickness of 2.8+nm.
It has a bending strength of 1200 kg/am2, which is comparable to the translucency and bending strength of standard porcelain.

The temperature range was 40'C, which showed better results than before.

Example 2 A kneaded molded product consisting of a synthetic mineral mainly composed of protoenstatite, 25% calcined talc, 20% silica, 5% silica, 15% tricalcium phosphate, 5% kaolin, was heated to a maximum temperature of 1140'C. Fired in a tunnel kiln for 24 hours.

The light transmittance of the porcelain product is 2.11% at a thickness of 2.61,
The bending strength was 1300 KH/c+s'', which was comparable to the standard light transmittance and bending strength mentioned above.The temperature range was 40'C, which showed better results than the conventional one.

The composition of the raw materials used in Example 1.2 was as shown in the following table.

(Functions and Effects) As clarified from the above explanation, the present invention is directed to a synthetic mineral mainly composed of protoenstatite, which has been conventionally used as a raw material for porcelain manufacturing, or a talc pottery.
Or a mixture thereof, silica, clay, etc., 1 to 20% of feldspar and 1 to 20% of a calcium-containing raw material smaller than the feldspar, so that the firing temperature is 1100 to 1200 ° C.
When fired at a low temperature, the porcelain properties of translucency and strength are almost the same as those of conventional firing temperatures of 1300°C or higher, and the firing temperature range is widened, making it easier to control the firing temperature. This has the effect of saving fuel, making it easy to control the firing temperature mentioned above, and providing a porcelain firing method with the same quality as conventional methods.

Claims (1)

[Claims] Synthetic mineral mainly composed of protoenstatite, which is a mixture of silica stone and magnesium hydroxide or magnesium carbonate, or talc ware, or a mixture thereof 30-70%
, 1 to 30% of silica, 1 to 20% of feldspar, 1 to 10% of limestone, wollastonite or calcium phosphate as a calcium-containing raw material, which is smaller than the above-mentioned feldspar, and 25 to 45% of clays.
A method for producing low-temperature fired porcelain, characterized by firing a base material formed by blending 1,100 to 1,200°C.