JPS6049145B2 - Method for manufacturing crystallized glass - Google Patents

Description

[Detailed description of the invention] The present invention relates to SIO.

, A1.03, MgO, ZnO, B.

O,,Na. O, TiO. This invention relates to a method for manufacturing crystallized glass for building materials, which involves melting, shaping, and heat treating glass whose main component is glass. Traditionally, natural stones such as marble and granite were mainly used for the exterior and interior walls of buildings, but in recent years crystallized glass has become preferred due to its excellent mechanical strength, thermal shock resistance, and chemical durability. It has become like that.

However, conventional crystallized glass has disadvantages such as high melting temperature, easy to postpone and difficult to form, high crystallization temperature, and the need to polish the surface.
It has been difficult to supply large quantities of crystallized glass building materials at low cost. The present invention improves the above-mentioned drawbacks of the conventional crystallized glass, and furthermore, it is easy to become rough during mechanical processing such as cutting, and it is possible to bend the crystallized glass by reheating it without damaging the surface condition. The purpose is to provide crystallized glass that can be used.

The present invention has 5i0040-60% by weight, A10001
5-25%, Mg00-12%, Zn00-12%, M
gO+Zn03~15%, Ti021~5%, B200
2-10%, Na004-13%, Zr000-3%,
000~5%, Ca00~5%, Ba00~5%, M
0030~1% and 5b0030~1% of the raw materials prepared to make glass are melted, this molten glass is formed into a plate shape by a normal method, and the molded product is heat-treated at a temperature of about 1000°C or less. , forsterite (2MgO-SI
O0) and carnite (ZnO-A1.

o. This is a method for producing crystallized glass characterized by precipitating crystals such as ). In the above glass composition,
SiO.

, A1. O. , MgO or ZnO are constituent components of the precipitated crystal, and TiO. is a nucleating agent necessary to precipitate crystals from glass. B. O. and N.A. O is a fluxing agent that aids in the solubility of glass. Furthermore, ZrO
.

is not an essential component, but TiO. 3% may be added as a component to assist in nucleation/formation. 202, CaO,
Although BaO and the like are not essential components, there is no problem in adding up to about 5% of each. NiO, Cr2O3, Fe2O3
One or more types of other colorants may be added. A.S.
Since 2Oa, Sb2O3, etc. are effective components as refining agents during glass melting, they may be added up to about 1%. Si
O. If it is less than 40%, the weather resistance of the crystallized product will be extremely poor, and if it is more than 60%, glass melting will become difficult. When Al2O3 is less than 5%, it becomes difficult to crystallize, and when it is more than 25%, glass melting becomes difficult. When ZnO and MgO each exceed 12%, the surface gloss of the crystallized product disappears, and the crystallized product cannot be reheated and bent. If the total amount of MgO and ZnO is less than 3%, crystallization is insufficient and 15%
If it exceeds this value, the surface gloss of the crystallized product will disappear. When TiO2 is less than 1%, nucleation is insufficient, and when it is more than 5%, the crystallized product becomes black and has an undesirable color tone. When B2O3 is less than 2%, glass meltability is poor, and when it is more than 10%, crystallization becomes difficult. Na2
If O is less than 4%, the melting properties of the glass are poor, and 13
%, the weather resistance of the crystallized product will be poor. If the ZrO2 content exceeds 3%, the meltability will deteriorate and it will be difficult to obtain a uniform glass. When K2O, CaO, and BaO each exceed 5%, crystallization becomes difficult and the heat treatment process becomes longer.
AS2O3, Sb. If O3 is more than 1%, the color tone of the crystal becomes dark. Table 1 shows examples of glass compositions of the present invention.

Figure 1 shows the glasses shown in Table 1 (NO.1, NO.3,
NO. 8) shows the relationship between viscosity (η) and temperature, and the liquidus temperature (TL) of each glass. Ordinary glass is formed (plates, etc.) at a temperature where the viscosity of the glass is in the range of 103 to 103.5 poise, but as can be seen from Figure 1, in the glass used in the present invention, the liquidus temperature and the forming temperature are different. Since there is a considerable temperature difference, glass can be easily formed without devitrification. Hereinafter, for convenience, N of the examples shown in Table 1
O. The present invention will be explained in detail regarding l glass.

First of all, stone powder, feldspar, aluminum oxide, magnesium oxide, lead oxide, titanium oxide, zirconium silicate, and nitrate! No acid soda, soda ash, borax, calcium carbonate, arsenite
．． The glass composition was mixed to have a glass composition of 1,000 °C, and poured into the melter section of a tank furnace maintained at about 1,400 °C.The temperature of the glass flowing to the feeder was adjusted to about 1,100 °C, and the orifice at the tip of the feeder was heated. from. Approximately 1050kg/Hr
The glass was flowed out at a speed of 1.06 m/min using rollers provided at the bottom of the orifice to form a plate having a width of 1020 Tf$L and a wall thickness of 7.5 mm. This plate glass was cut to a length of 120 cm and strain was removed in a slow cooling furnace. The obtained glass had a slight yellowish tinge, and small irregularities due to the finishing marks of the roller were observed on the surface. This glass plate was placed on a mullite shelf board pre-assembled on a trolley, and placed in a tunnel furnace from room temperature to 900 C.
The sample was heated at a rate of 000C/Hr, held at 900C/Hr for 1 hour, and then cooled at an average rate of 100C/Hr. The resulting board is white and glossy, and the small irregularities caused by the roller finishing that were seen on the glass board have disappeared, making it a beautiful product with a surface quality that is equal to or better than that of a smooth, flat polished natural stone product. Ta. As a result of X-ray diffraction, the precipitated main crystals were forsterite (2Mg0-SiO2) and gahnite (Z
nO-Al2O3). Table 2 shows the physicochemical properties of this crystallized product. From this table, it can be seen that it has excellent properties as a wall material for buildings. Table 3 shows a comparison of the mechanical properties of granite, which is commonly used as a building material, and the crystallized glass of the present invention (Example No. 1).

The amount of grinding was measured using a grinding machine with diamond cup wheels arranged in order of 100 diameters on a sample having a size of 50 x 50 x 1 DIr$t.

Regarding bending strength and hardness, 10 x 50 x 300Tr
rft size samples were measured using a three-point loading type bending strength meter and a Shoer hardness meter.

As is clear from Table 3, the amount of grinding of the crystallized glass of the present invention is nearly twice that of granite.

This indicates that mechanical processing such as grinding and cutting is easy. Although mechanical processing is easy, the bending strength is approximately five times higher and the hardness is also high, making the crystallized glass of the present invention extremely excellent as a building material. In buildings, walls with cylindrical or cylindrically curved surfaces are often used.

With natural stone, large blocks had to be ground to create curved surfaces. With the crystallized glass of the present invention, a desired curved surface can be easily obtained by placing a flat plate on a convex or concave curved mold and heating it. This bending process can be performed at the same time as the crystallization heat treatment, but the feature of the crystallized glass of the present invention is that it is already crystallized! The flat plate obtained by this method can be easily bent at a temperature lower than the crystallization heat treatment temperature. Moreover, the surface of the obtained curved product maintains the same gloss and smoothness as a polished product. For example, Example No. 1 obtained as described above. 1 of flat crystallized glass products (crystallized at a crystallization temperature of 900'C) were placed on a 950R stainless steel mold, 120)
A curved product of 950R was obtained by heating at a rate of C/Hr and holding at 800°C for three times, but the surface condition remained smooth and glossy without any change. FIG. 2 shows Example No. Figure 9 shows the thermal expansion curves of the glass before crystallization and the crystallized glass.

The thermal expansion characteristics of the crystallized material exhibit a pattern similar to that of the original glass, and soften at the bending point Tf. That is, the crystallized glass of the present invention has a low crystallinity and exhibits properties similar to glass,
Similar to glass, the material 7 can be bent at a temperature approximately 100° C. higher than the bending point Tf. Implementation FANO. The crystallized glass of I is white, or by adding one or more types of coloring agents to the raw materials, crystallized glass of various colors can be obtained.

The crystallized glass of the present invention has a low melting temperature and is easy to melt, and since there is a considerable temperature difference between the liquidus temperature and the forming temperature, it does not devitrify during forming, has a low crystallization temperature, and can be crystallized. can be bent by reheating at a temperature below the crystallization temperature.

In addition, it is easy to machine, has high bending strength and hardness, and has excellent acid resistance, alkali resistance, and weather resistance, making it a valuable building material.

[Brief explanation of the drawing]

FIG. 1 is a graph showing the relationship between the viscosity and temperature of the glass of Example No. 2 of the present invention, and FIG. 1 is a graph showing the thermal expansion characteristics of glass No. 1 before and after crystallization.

Claims (1)

[Claims] 1% by weight SiO_240-60%, Al_2O_3
15-25%, MgO 0-12%, ZnO 0-12%,
MgO+ZnO3~15%, TiO_21~5%, B_
2O_32~10%, Na_2O4~13%, ZrO_
20-3%, K_2O0-5%, CaO0-5%, Ba
O0~5%, As_2O_30~1%, Sb_2O_3
A method for producing crystallized glass, which involves melting, shaping, and heat-treating raw materials prepared to make glass containing 0 to 1%.