JPS60122748A - Aluminosilicate glass - Google Patents

Abstract

PURPOSE:To develop the titled glass which can be produced in large quantities without requiring the coating for preventing elution of alkali and without the deterioration of performance due to the elution of alkali by using the aluminosilicate glass as the starting material to manufacture the glass which is used as the substrate glass for electronic parts. CONSTITUTION:The glass is manufactured by melting as substrate glass having 0.3-1.0mm thickness which is used for a liquid crystal apparatus. The glass contains 50-62% SiO2, 10-18% Al2O3, 2-5% B2O3, 0.5-7% MgO, 4-13% CaO, 0-7% BaO, 3-10% ZnO, 0-2% LiO2, 0-10% Na2O, and 0-10% K where Li2O+Na2O+K2O=3-11%. The glass is charged into a mold made of stainless steel, and then annealed. The glass which has no deterioration in performance due to the elution of alkali and can be used as the substrate glass for members of electronic and electric products such as a liquid crystal substrate can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an aluminosilicate glass suitable for electronic equipment substrate glass that can be continuously manufactured.

The substrate glass for liquid crystal etc. is 0.3 to 1. Omm thin plates are used, but in order to continuously and efficiently manufacture these thick plate glasses from a glass melting chamber, the Full Pern process, Fourcor process, and float process Nijol plate manufacturing methods are adopted. The glass composition most suitable for the above-mentioned sheet manufacturing method is when used as a substrate glass for soda lime silica glass, which has traditionally been used for architecture, vehicles, etc.
There was a drawback that the elution of alkali from the substrate glass deteriorated the performance. In order to improve this drawback, a method has been adopted in which a 5i02 film is formed using ethyl silicate on the surface of a soda lime silica glass substrate to prevent alkali elution from the substrate glass.

On the other hand, it has a low alkali content and less alkali elution.
Although there are glass compositions that do not require coating with the J-02 film, it is difficult to make plates using the three methods mentioned above, and after making plates using the roll-out method, the surface can be polished to form a substrate glass, or the surface can be polished using the roll-out method. After plate manufacturing, the polished plate glass is reheated and stretched to produce glass with a thickness of 0.3 to 1/2 mm and used as the substrate glass, or a very special plate manufacturing method not suitable for mass production (for example, a special plate manufacturing method) is used. It is said that glass with a thickness of 0.3 to 0.0 mm is made by adopting the flow down method (Kousho Il≦-2'190).

Moreover, in these cases, the footing of the 5i02 membrane! Even if it is unnecessary, its benefits are halved due to the low productivity of the substrate glass.

The present invention solves these disadvantages and provides an aluminosilicate glass that can be continuously produced in large quantities by the Fourcor method, Colburn method, or float method, and does not require an alkali elution prevention coating.

The aluminosilicate glass according to the present invention is expressed in weight and %: 5i02 j ON62% B2O32~5% A7203 lO~11r% MgOO,! r~ 7% CaQ II-13% BaOO~ 7% zno 3~lo% Li, 20 0~2% Na2O0N10%, 20 0~10% However, 20 wJ~//% for Li2O+Na2O+
It has as a basic component.

The reasons for limiting the composition in the present invention are as follows.

Sio2 is the main glass-forming oxide in the glass of the present invention, but if it exceeds 42%, the viscosity of the glass increases and its solubility deteriorates. Moreover, if it is less than 50%, the chemical durability of the glass will be significantly impaired, so 50% is set as the lower limit. A preferred range is 5lI-s, r%.

B2O3 lowers the high-temperature viscosity of glass and makes it easier to melt, but B2O3 alone or in combination with an alkali component easily volatilizes from the glass base, causing defects such as striae and creases when glass is formed. There is. As the content of B2O3 increases, the volatilization of the glass base material becomes more intense, so the upper limit of B2O3 is 3%.If B2O3 is less than 2%, it becomes difficult to melt the glass, so the lower limit is set to 2%. . The preferred range is 11-5%.

In the case of aluminosilicate glass, Al2O3 improves the stability and chemical durability of the glass. If it exceeds itr%, the viscosity of the glass increases and the solubility deteriorates, and
If it is less than that, chemical durability will deteriorate.

The preferred range of Al2O3 for glass stabilization is 3/=j-'4j%. MgO improves the chemical durability of glass and lowers its coefficient of thermal expansion, but if MgO exceeds 7%, the devitrification temperature of glass increases and its solubility deteriorates.

Moreover, if it is less than 0.3%, the chemical durability of the glass will decrease.

Preferably it is o3-p%. CaO lowers the high-temperature viscosity of glass and facilitates glass melting, but if CaO exceeds 13%, the devitrification temperature of glass increases, and if it is less than t%, it becomes difficult to melt glass.

Although BaO is not an essential component, adding about S% of BaO significantly lowers the devitrification temperature of the glass and facilitates molding. However, if it exceeds 7%, the chemical durability of the glass will deteriorate. ZnO lowers the high-temperature viscosity of glass and makes it easier to melt the glass, but when it exceeds 70%, the slope of the wetting-viscosity curve of the glass becomes steep, and the viscosity changes greatly with minute changes in humidity, making molding difficult.

Moreover, if it is less than 3%, the high temperature viscosity will not be lowered sufficiently and dissolution will become difficult. Preferably the range is 5-7%.

I, i20 s Na2O, and K2O all promote glass melting, but considering that Ld20 is an expensive raw material, the upper limit is set at 2%. If Na2O and 20 each exceed 70%, the chemical durability of the glass will decrease and the amount of alkali elution will increase, so the upper limit for each is set at 10%. However, if Li2O+Na2O+ contains less than 3% of 20, the melting of the glass will deteriorate, so the lower limit is set at 3%. Moreover, if the total amount of the three components exceeds 11%, the chemical durability will deteriorate and the amount of alkali elution will increase, so the upper limit is set at 11%. 3 to 9% is preferred.

In addition to the above-mentioned basic components, impurities such as TiO2, Fe2O2, which are mixed in from the glass source 171,
etc., it is acceptable even if the type is less than 0.5%.

Also, as a normal clarifier T 5b2o31 Ag2O3t
1% or less of each of SOs z F2 tC12, etc. may be included. Furthermore, oxides commonly used for the purpose of coloring glass, such as MnO2, Qr, 3 g Coo
A small amount of tNIOyGuQ or the like may be included.

As described above, the reason for limiting each component is that the aluminosilicate glass according to the present invention is suitable for continuous plate manufacturing by the Fourcor method, the Colburn method, and the float method. (TW) The relationship force Tw-TL5fo''c is required, and it is preferable that TW≧TL.

Next, the present invention will be explained in detail based on examples. 1st
Prepare batches with the mixing ratio necessary to obtain glasses with the target compositions of A/ to A/2 and Comparative Example 1゜2 shown in the table, and place them in a platinum crucible. The mixture was melted at 0''C (1), poured into a stainless steel mold, molded, and slowly cooled.

The values of the devitrification temperature (T, r, ), working temperature (TV), and TV-Tl of the various glasses listed in Section 2 are as shown in the table, and the examples according to the present invention all have good alkali elution resistance. In contrast, conventional typical alkali elution resistant glass has TV-TL < -30°C as shown in Comparative Example/2, and is suitable for large quantities. The temperature characteristics are unsuitable for continuous plate making, and the commercially available float glass composition of Comparative Example 3 has an alkali elution amount of about 7.
Reach 0 times. Therefore, it has become clear that the glass of the present invention can be continuously produced in large quantities and has excellent alkali elution resistance, making it excellent as a glass for substrates of electronic equipment.

The devitrification temperature (TL) used in the above explanation was determined as follows.

Shatter the glass and pass through a 16x08m flue to 1190
The glass particles remaining on the μm sieve were placed over a number of holes with a diameter of 7 mm drilled in a row on a platinum boat, and the glass particles were placed on a platinum boat with an appropriate Wllt degree gradient total gradient of 1 JIA in the length direction of the boat.
After allowing the platinum boat to cool naturally, the glass grains on the platinum boat were observed using a microscope, and the highest temperature at which devitrification occurred was defined as the devitrification temperature. Also, working temperature (Tw)
is the temperature at which the viscosity of the glass becomes /(74 voices).

ioo℃,! ; This is the value obtained by analyzing the amount of alkali eluted into the water after boiling it in 0 ml of water for 0 minutes.

Table 1

Claims (2)

[Claims] (1) Expressed in weight%, 5102 jOA-4-? %yB203 2~S%, A
A'203 io~/I%, MgOO,! r ~7%,
Ca0II~73%, BaQO~7%, zno 3~I
O%+L 120 ON2%+N a 20
0-10%, 20 0-10% + Li2O + Na2O
An aluminosilicate glass characterized in that it has a basic component of +20-3 to //%. (2) 5i02 expressed in weight%! ;Su~Sza%p B 203 Gu~j%v
A1203/3~is%, MgOO,! r~lI%, C
a07~11%, BaQ, (7~5%, ZnO!r~7
%, Li200-1%, Na2O3-9% aluminosilicate glass.