JPH04280834A - Colored glass - Google Patents

Abstract

PURPOSE:To provide the title borosilicate glass of unconventionally low thermal expansion coefficient. CONSTITUTION:The objective glass comprising (A) 73.90wt.% of SiO2, (B) 17.62wt.% of B2O3, (C) 2.39wt.% of Al2O3, (D) 0.31wt.% of BaO, (E) 0.92wt.% of Li2O, (F) 1.51wt.% of Na2O, (G) 2.75wt.% of K2O, (H) 0.15wt.% of Fe2O3, and (I) 0.45wt.% of Er2O3, having the main wavelength determined by a C-light source being 590nm. The present glass, which is low in thermal expansion coefficient and excellent in chemical resistance, is suitable as plate glass for use in fire doors.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to architectural and vehicle glass.

0002

2. Description of the Related Art Most of the glass for buildings and vehicles that has been used in the past is so-called soda-lime silica glass, and borosilicate glass as related to the present invention is not used. However, recently, transparent borosilicate glass, which has a low coefficient of thermal expansion, has been proposed as an architectural fire protection glass to replace conventional wired glass. Examples include pyran invented by Schott of Germany, and low expansion glass proposed by the present inventors (Japanese Patent Laid-Open No. 1-93437).

0003

[Problems to be Solved by the Invention] However, all of these glasses are colorless and transparent, and colored low expansion borosilicate glasses have not conventionally existed.

[0004] When the above-mentioned borosilicate glass is used for architectural and vehicle applications, it is preferable for various designs to have various colored glasses, similar to soda-lime-silica glass. The present invention takes these points into consideration and provides a colored borosilicate glass with a low coefficient of thermal expansion, which has not existed heretofore.

[0005]

[Means for Solving the Problem] The colored glass according to claim 1 has a content of 71 to 83% SiO2, expressed in weight percent, and 10 to 83% SiO2.
20% B2O3, 1-4% Al2O3, 0-0.6
% MgO, 0-0.6% CaO, 0-2% BaO
, 0-1% ZnO, 0-2% Li2O, 0-6% Na2O, 0-5% K2O, 0.1-0.8% Fe
2O3, 0-0.05% CoO, 0-0.1% Ni
It is characterized by comprising O, 0.2 to 2.0% Er2O3, and having a dominant wavelength of 575 to 610 nm as measured using a C light source.

[0006] Here, Fe2O3 indicates all the iron oxides contained in the glass converted into Fe2O3.

[0007]

[Operation] The reasons for limiting the composition of the present invention are as follows. Si
O2 forms a glass skeleton together with B2O3 and Al2O3. If the SiO2 content is less than 71%, the coefficient of thermal expansion becomes too large and there is no point in using borosilicate glass. 8
If it exceeds 3%, the solubility of the glass decreases.

B2O3 improves the meltability of glass without increasing the coefficient of thermal expansion of glass. If B2O3 is less than 10%, the solubility of the glass deteriorates. When B2O3 exceeds 20%, the chemical durability of the glass decreases.

[0009] Al2O3 improves the chemical durability of glass. If Al2O3 is less than 1%, chemical durability will decrease. If it exceeds 4%, the solubility of the glass will deteriorate.

Although MgO, CaO, BaO, and ZnO are not essential components, they can be used as necessary to improve solubility and chemical durability. However, since these components increase the coefficient of thermal expansion, the upper limit is MgO.
, CaO is 0.6%, BaO is 2%, and ZnO is 1%. Further, it is desirable that the total amount of these divalent metal oxides does not exceed 2%.

[0011] Li2O lowers the viscosity of glass at high temperatures and improves its solubility. If Li2O exceeds 2%, the effect will not increase and the raw material cost will increase, so the upper limit is set at 2%.

[0012] Na2O also improves the solubility of glass, but if it exceeds 6%, the coefficient of thermal expansion of the glass increases, which is undesirable.

[0013] K2O improves the chemical durability of glass when combined with Na2O and Li2O, but if it exceeds 5%, it increases the viscosity of the glass and increases the coefficient of thermal expansion, which is not preferable.

[0014] Fe2O3 indicates a value obtained by converting all iron oxides present in the glass into Fe2O3. Fe2O
3 absorbs the short wavelength portion and the long wavelength portion of visible light, and alone colors the glass gray with a dominant wavelength of 570 to 580 nm. If Fe2O3 is less than 0.1%, there is no coloring effect;
If it exceeds 8%, the coloring becomes too strong, so the upper limit is set at 0.8%.

[0015] CoO has the effect of turning glass blue, but
If it exceeds 0.05%, the glass becomes too blue, which is not preferable.

NiO has the effect of imparting an orange color to glass, but if it exceeds 0.1%, the orange color becomes too strong, which is not preferable.

[0017] NiO and CoO are not used alone. Used for fine adjustment of coloring by combination of Fe2O3 and Er2O3.

[0018]Er2O3 is used to impart a reddish tint to the coloring by Fe2O3. If Er2O3 is less than 0.2%, the effect is small, and if it exceeds 2.0%, the glass becomes too red, so 2.0% is the upper limit.

In addition to the above components, clarifiers (such as As2O3, Sb2O3,
SO3, Cl, F, etc.) or impurities (TiO2, etc.) may be included.

[0020]

EXAMPLE Glass raw materials having the composition shown in Table 1 were prepared, placed in a 90Pt-10Rh crucible with a capacity of about 250 ml, and melted at 1550° C. for 20 hours in an electric furnace. After pouring the molten glass onto a preheated stainless steel plate, it was kept in an electric furnace maintained at 700° C. for 30 minutes to slowly cool it. The slowly cooled glass was cut and polished to prepare samples for measuring optical properties.

[0021]

[Table 1]

The optical properties shown in Table 1 are the results of measurements of a 5 mm thick sample using a C light source.

[0023]

As the colored glass according to the present invention has a small coefficient of thermal expansion and excellent chemical durability, it is particularly suitable as plate glass for use in fire doors of high-rise buildings.

Claims (1)

[Claims] Claim 1: 71 to 83% S expressed in weight%
iO2, 10-20% B2O3, 1-4% Al2O
3, 0-0.6% MgO, 0-0.6% CaO, 0
~2% BaO, 0-1% ZnO, 0-2% Li2
O, 0-6% Na2O, 0-5% K2O, 0.1-
0.8% Fe2O3, 0~0.05% CoO, 0~
It consists of 0.1% NiO and 0.2-2.0% Er2O3, and the dominant wavelength measured using a C light source is 575-61
A colored glass characterized by having a particle diameter of 0 nm.