JPH04338131A - Crystallized glass - Google Patents

Abstract

PURPOSE:To obtain a crystallized glass which satisfies various requirements for building material and can be produced at high yield since the liquid phase temp. is low. CONSTITUTION:The glass has such a composition, by wt.%, 40.0-60.0wt.% SiO2, 14.0-25.0% Al2O3, 0.1-15.0% ZnO, 0-12.0 MgO, 0-6.0% TiO2, 0.6-4.0% ZrO2, 10.1-20.0% B2O3, 2.0-20.0% Na2O+K2O+Li2O, 0-40% BaO, 0-1.0% As2O3, and 0-1.0% Sb2O3 and has deposition of gahnite as the main crystal.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to crystallized glass, and more particularly to crystallized glass suitable as a building material.

0002

[Prior Art] Various crystallized glasses have been proposed as exterior and interior materials for buildings.
No. 1-136938 contains forsterite (2MgO・S
A crystallized glass in which iO2) is precipitated as a main crystal is disclosed.

0003

[Problems to be Solved by the Invention] Generally, crystallized glass used for the above-mentioned purposes is required to have excellent properties such as chemical durability and mechanical strength, and to have a beautiful appearance.

However, the above-mentioned crystallized glass in which forsterite is precipitated as a main crystal does not fully satisfy these requirements in terms of chemical durability and mechanical strength. Furthermore, the crystallized glass disclosed in JP-A-61-136938 does not have a beautiful glossy surface because fine irregularities remain on the surface after the crystallization heat treatment.
Therefore, a polishing step is required. Moreover, since this crystallized glass has a high liquidus temperature, the forming temperature range is extremely narrow. Therefore, the raw glass tends to devitrify during molding, making it difficult to manufacture with a good yield.

[0005] An object of the present invention is to provide a crystallized glass that satisfies various conditions required for building materials and that can be manufactured with high yield due to its low liquidus temperature.

[0006]

[Means for Solving the Problems] As a result of various studies, the present inventors have found that gahnite (ZnO. By precipitating Al2O3) as the main crystal, crystallized glass that satisfies the conditions required for building materials can be obtained, and by setting the content of B2O3 to 10.1% or more, the liquid phase It has been discovered that the temperature can be lowered, and this is proposed as the present invention.

That is, the crystallized glass of the present invention contains 40.0 to 60.0% SiO2 and 14% Al2O3 by weight.
．． 0-25.0%, ZnO 0.1-15.0%, M
gO 0-12.0%, TiO2 0-6.0%, Z
rO2 0.6-4.0%, B2 O3 10.1-2
0.0%, Na2O+K2O+Li2O 2.
0 to 20.0%, CaO 0 to 4.0%, BaO 0 to
4.0%, As2 O3 0-1.0%, Sb2 O3
It has a composition of 0 to 1.0% and is characterized by precipitated gahnite as the main crystal.

[0008]

[Operation] The crystallized glass of the present invention precipitates gahnite as the main crystal, which has excellent chemical durability and mechanical strength. Additionally, the chemical durability and mechanical strength of the glass will generally increase as the amount of SiO2 in the glass matrix layer increases, but since gahnite does not contain SiO2 in its crystals, it contains a large amount of SiO2 in the glass matrix phase. ingredients will be included. Therefore, the obtained crystallized glass is excellent in these properties. Moreover, Garnite is C
Since it is a crystal that can dissolve coloring elements such as r and Ni, by adding these coloring components, it is possible to obtain crystallized glass exhibiting a vivid color tone.

Next, the reasons for limiting each composition as described above will be described below.

[0010] SiO2 is a component that increases chemical durability, and its content is 40.0 to 60.0%, preferably 40.0% to 60.0%.
It is 2.0 to 58.0%. If the SiO2 content is less than 40.0%, the weather resistance will be extremely poor, and if it is more than 60.0%, it will be difficult to melt the glass.

Al2 O3 is a constituent of gahnite, and its content is 14.0 to 25.0%, preferably 14.5 to 24.5%. Al2O3 is 14.
If it is less than 0%, it becomes difficult to crystallize, and if it is more than 25.0%, the meltability of the glass deteriorates.

[0012] ZnO is a component of gahnite, and its content is 0.1 to 15.0%, preferably 0.5 to 1%.
It is 2.0%. When ZnO is less than 0.1%, gahnite does not precipitate, and when it is more than 15.0%, the liquidus temperature becomes high and the forming temperature range of the raw glass becomes narrow.

[0013] MgO is a component that stabilizes glass, and its content is 0 to 12.0%, preferably 0.1 to 1%.
It is 0.0%. If MgO is more than 12.0%, foreign crystals such as forsterite will precipitate, resulting in a decrease in chemical durability. Further, the crystallized glass becomes difficult to be colored.

[0014] In order to precipitate gahnite as the main crystal, it is preferable that the content of ZnO be greater than that of MgO.

[0015] TiO2 is a nucleating agent, and its content is from 0 to 6.0%, preferably from 0.1 to 5.0%. If the TiO2 content is more than 6.0%, the crystal growth rate becomes extremely high, making it difficult to control the amount of crystals.

ZrO2 is also a nucleating agent, and its content is from 0.6 to 4.0%, preferably from 0.6 to 3.5%. If ZrO2 is less than 0.6%, nucleation will be insufficient and crystal precipitation will be concentrated near the surface, resulting in decreased fluidity. Therefore, fine irregularities remain on the surface, making it impossible to obtain gloss. On the other hand, if the ZrO2 content is more than 4.0%, devitrification tends to occur, making it difficult to stably melt the glass.

B2 O3 has the effect of improving the meltability of glass and lowering the liquidus temperature, and its content is 10.1
-20.0%, preferably 10.1-18.0%. If B2 O3 is less than 10.1%, the meltability of the glass will be poor, the liquidus temperature will be high, and the raw glass will be more likely to devitrify during molding. On the other hand, if it exceeds 20.0%, crystallization becomes difficult.

[0018] The total amount of Na2O, K2O and Li2O is 2.0 to 20.0%, preferably 2.5 to 19.5%.
contains. If the total amount of Na2O, K2O and Li2O is less than 2.0%, the meltability of the glass will be poor,
%, it becomes difficult to crystallize.

[0019] The contents of CaO and BaO are each 0 to 4.
．． It is 0%. If CaO and BaO are each more than 4.0%, crystallization becomes difficult.

As2 O3 and Sb2 O3 are each contained in an amount of 0 to 1.0% as clarifying agents. In addition to the above-mentioned components, the crystallized glass of the present invention also contains CoO, Ni
O, Fe2 O3, MnO2, Cr2 O3, C
It is possible to add up to 10% of colored oxides such as eO2.

[0021]

EXAMPLES The present invention will be explained below based on examples.

Table 1 shows examples of the present invention (sample No. 1 to
5) and a comparative example (sample No. 6).

[0023]

[Table 1]

[0024] Table No. Each of samples 1 to 6 was prepared as follows. A batch of raw materials prepared to have the composition shown in the table was heated at 1500 to 1580℃ for 12 hours using a platinum crucible.
After melting for ~16 hours, the molten glass was poured onto a carbon table and formed into a plate shape using a roller. Next, this plate-like material was heated to 950°C to 1100°C at a heating rate of 120°C/h.
After heating to and holding for 1 hour, a sample was obtained.

As is clear from the table, sample No. 1, which is an example, 1 to 5 precipitate gahnite as the main crystal,
Acid resistance 0.1~0.5mg/cm2, alkali resistance 0.5~1.2mg/cm2, bending strength 1050
〜1200kg/cm2, and the liquidus temperature is 980〜
The temperature was 1060°C. Also, sample No. 1 and 2 are white,
Sample No. 3 is green, sample No. 4 is blue, sample N
o. No. 5 exhibited a pink color, and each sample had a beautiful glossy surface.

On the other hand, sample No. 1, which is a comparative example, 6
precipitates forsterite as the main crystal, and has acid resistance of 7.5 mg/cm2 and alkali resistance of 3.2 mg/cm.
m2, bending strength was 800 kg/cm2, and liquidus temperature was 1200°C. Although the color tone was white, no surface gloss was obtained.

These facts indicate that the crystallized glass of the present invention has excellent chemical durability and mechanical strength because it precipitates gahnite as the main crystal, and also has a beautiful appearance.
This shows that the liquidus temperature is low because it contains 10.1% or more of 2 O3.

The precipitated crystals in the table were determined by X-ray diffraction, and the acid resistance and alkali resistance were measured at 90°C and 1% H2.
SO4, 25 x 25 x 5 mm in an aqueous solution of NaOH
The sample (mirror polished product) was immersed for 24 hours and then evaluated based on the weight loss. The bending strength was measured by a three-point loading method using a sample of 10 x 70 x 8 mm. The liquidus temperature was measured after placing the glass in a platinum boat and holding it in a temperature gradient furnace for 15 hours.

[0029]

As explained above, the crystallized glass of the present invention has excellent chemical durability and mechanical strength, and has a beautiful appearance, so it is suitable as a building material. Furthermore, the crystallized glass of the present invention has a low liquidus temperature and is difficult to devitrify during molding of the raw glass, so it can be manufactured with a high yield.

Claims (1)

[Claims] Claim 1: SiO2 40.0 to 60.0% by weight.
0%, Al2O3 14.0-25.0%, ZnO
0.1-15.0%, MgO 0-12.0%, T
iO2 0-6.0%, ZrO2 0.6-4.0%,
B2 O3 10.1-20.0%, Na2 O+K2
O+Li2O 2.0-20.0%, CaO
0-4.0%, BaO 0-4.0%, As2O3
A crystallized glass having a composition of 0 to 1.0% Sb2O3 and 0 to 1.0% Sb2O3, and formed by precipitating gahnite as the main crystal.