JPS63147843A - Glass composition - Google Patents

Abstract

PURPOSE:To form a glass compsn. for flakes and fibers having good workability and excellent chemical durability at a low cost by using the specific glass compsn. CONSTITUTION:This glass compsn. consists of at least 95wt% in total the following components: The compsn. is formed by compounding, by weight %, 63.0-67.0 SiO2, 4.0-4.8 B2O3, 4.0-5.5 Al2O3, 0-4.0 TiO2, 2.5-3.6 MgO, 4.7-8.7 CaO, 5.0-0 BaO, 7.5-13.9 Na2O, 2.0-0 K2O, 8.0-15.5 Na2O+K2O, 0-1.0 Fe2O3, and 0-5.0 ZrO2. The above-mentioned glass compsn. has preferably the working temp. higher by >=150 deg.C than the liquid phase temp. in order to assure the good workability. The liquid phase temp. of this glass compsn. is preferably <=1,050 deg.C in order to avoid the molding work at a high temp.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a glass composition, particularly to a glass composition for breakers and fibers having excellent chemical durability.

[Conventional technology]

Conventionally, glass fiber with excellent chemical durability has been known as C glass, and its typical composition is K, L, L.
The Manufacturer by Oe Wenstein
ir+gTechnology of Continue
ous Glass Fibers (ELSEVIER
, / 913) on page 31, heavy N% Te5i026! ; + B2O3! ;, AA'2034
', MgO3+cao IL Na2Ot,! ; , F
It is e2O30.3. Although the raw material cost of this C glass is low, the temperature difference between the working temperature (the temperature at which the viscosity of the glass becomes 1000 poise) and the liquidus temperature is less than 50°C, and the glass composition can be spun, but is difficult to manufacture due to the occurrence of devitrification. Since glass break is mixed with a paint and applied to the inner surface of a steel pipe to prevent wear and rust on the inner surface of the steel pipe, it is naturally required to have chemical durability. Therefore, A glass with good workability (LOeW)
According to enSte:LnK, weight-% is 5i0272.
0. Al2O3-2,5, B2O30J, MgO(+,
q, cao 9.0°Na2O/2.6. 20 /
-j+Fe2O30,j> glass 7lake has poor chemical durability and is not practical. Further, even when short glass fibers are produced by flame drawing, the C glass cannot be used because devitrification occurs.

The glass composition disclosed in U.S. Pat. r-62,1)
203/-,! ,cao r-9,! ; , Mg
O2J-3,! ; , Na2O/j-/7, 200
−/ , B2O3j-7.

Li2O0,/-0,u, znO/, yo-3,5 Teal. The Kono composition improves workability by increasing Na2O, and improves chemical durability by adding L120 and ZnO. However, Li2O and ZnO are very expensive.

[Problem that the invention seeks to solve]

As mentioned above, cheap C glass has poor workability, and glass with good workability is expensive;
It can be said that no glass composition with sufficient chemical durability has hitherto existed.

The present invention solves this contradiction and proposes a glass composition for 7 lakes and fibers that is inexpensive, easy to work with, and has excellent chemical durability.

[Means to try to solve problems]

The gist of the present invention essentially consists of the following composition expressed in coulometric %: 5i02 63.0-67.0B203
'1. ,0-1f,1A1203
tl, 0-! ;、! ;TiO20-≠, 0 Mg0, 2.6-3.6CaO
#, 7-r, 7 BaOO-! ;, 0 Na20 7. j-/J, 9 to 20
0-λ, 0Na20 + K2
OIr, 0-/ r, rFe2O30-/, 0 Zr02 0-! ; , 0.

In order to ensure good workability, the glass composition must have a working temperature of /! below the liquidus temperature. ; It is preferable that it is higher than O'C. More preferably, the liquidus temperature of the glass composition is /O! in order to avoid molding operations at high temperatures. ; O''C or less. Also, since the glass composition is required to have chemical durability, the acid resistance and water resistance are 7% or less expressed as weight loss (see Examples for the test method).

[For production]

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

5102 forms a glass skeleton together with B2O3r Al 203. When 1 of 5i02 exceeds 67.0%,
As the solubility of the glass decreases, the working rM of the glass
degree, the liquidus temperature increases, which is undesirable. If the SiO2 stone content is less than 63.0%, the chemical durability of the glass will deteriorate, which is not preferable.

When B2O3 exceeds <z, r%, it is not preferable because it increases the raw material cost of the glass and reduces the humidity difference between the working temperature and the liquidus temperature of the glass. If B2O3 is less than 0%, the viscosity of the glass increases and the working temperature and liquidus temperature increase, which is undesirable.

Al2O3 is an essential component because it improves the chemical durability of glass, especially water resistance, but it has no effect on improving water resistance even if it exceeds 5%, so 5.5% is the upper limit, and 1
). If it is less than 0%, the water resistance decreases, so ψ, O% is set as the lower limit.

Although TlO2 is a component that improves chemical durability, it is preferable not to use it because the raw material is expensive. When used, it is chemical even if it exceeds 0%).

Since there is no effect of improving durability, the upper limit is set at 0.0%.

MgO and CaO are fluxing agents for glass. At the same time, they are used in combination to keep the viscosity curve of the glass appropriate and also to maintain chemical durability. In the present invention, since MgO lowers the liquid f@humidity temperature within the range of jJ to 3.6%, it is limited to this range. CaO is not preferable if it exceeds L7% because it increases the liquidus temperature.

If L is less than 7%, it is not preferable because it lowers chemical durability.

BaO is a component that acts as a fluxing agent and lowers the liquidus temperature without reducing chemical durability.

However, since the raw materials are relatively expensive, it is preferable not to use it. Even when BaO is used, if it exceeds LO%, the effect of lowering the liquidus temperature becomes small, so the upper limit is set at 5.0%.

Na2O and 20 are glass fluxing agents. Since 20 is a more expensive raw material than Na2O, it is preferable to use Na2O as the main component.

If Na2O exceeds 13.9%, the chemical durability of the glass decreases, so the upper limit of Na2O is 13.9%.

When Na2O is less than 74%, the solubility of the glass decreases,
At the same time, the liquidus temperature also increases, which is not preferable.

Therefore, the lower limit of Na2O is set at 7.5%. K2O does not need to be specially prepared as a glass raw material, but it may be mixed in from raw materials used to introduce components other than 20 into silica sand, feldspar, etc., so the upper limit is set at 2.0%.

It is known that chemical durability can be improved by the mixed alkali effect if 20 is introduced in place of Na2O, but the main aim of the present invention is to propose an inexpensive glass composition. Therefore, from this point of view, the upper limit for 20 is 2.0%. Furthermore, Na, 20 20 in ten is N
For exactly the same reason as stated in section 20, the upper limit is set to /jJ% and the lower limit is set to 0%.

Although Fe2O3 is not an essential component, it is mixed as an impurity in the glass raw material, so the upper limit is set at 0%.

ZRO2 is a component that increases chemical durability, but it
When K is used, it increases the viscosity of the glass and reduces the solubility, so the upper limit is set at 3.0%.

The effects of the glass components have been described above, but when chemical durability is particularly important, it is preferable to use TlO2 and ZrO2 in amounts up to q and 0% by weight and j and 0% by weight, respectively. The composition of the present invention contains at least 95% by weight of the above-mentioned ingredients. That is, ZnO as a middle component is at most 7% by weight, SrO is at most 7% by weight, PbO is at most /% by weight, etc., W! As acid components, AS203 may be contained in an amount of at most O, S, and 5b203 may be contained in an amount of at most 0.5 weight %.

〔Example〕

Next, examples of the present invention will be described. Composition in Table 1 (
(wt%) by melting glass with working temperature, liquidus temperature,
Water resistance and acid resistance were measured. The results are shown in Table 1.

The liquidus temperature was determined by pressure as follows.

Crush the glass and pass it through a 1610μm sieve //9
The glass particles remaining on the 0 μm sieve were immersed in alcohol, washed with ultrasonic waves, and dried under constant pressure. These glass grains were placed in seven rows on a platinum boat.
The boat was held for 4 hours in a furnace whose temperature was set to have an appropriate temperature gradient in the lengthwise direction of the boat at the top of a number of holes with a diameter of 1.5 inch. 'Observe the glass particles on the platinum port taken from the furnace,
The highest temperature at which devitrification occurred was defined as the liquidus temperature.

1) One constant of water resistance was determined as follows. Glass is placed in a spinning platinum pot and glass fibers with a diameter of 9 μm are spun. Approximately 2 g of glass IFi fiber cut into approximately 30 mm length is taken and kept in a desiccator for one hour to dry.

The weight of this sample is precisely weighed to the nearest o./mmg. Next K
Put the M material into a Pyrex glass beaker and add 200ml of distilled water. This beaker is placed in a constant temperature slide held at to''c and held for S time. During this time, the beaker is shaken as appropriate.

This liquid is filtered through a glass filter, and the sample is washed with distilled water. After thoroughly drying the sample, its weight is reduced to 0, Immg.
Weigh accurately. The weight loss of the sample after the test with respect to the initial weight of the sample is expressed in weight% and is defined as water resistance.

Measurement of acid resistance is classified as 4 in the measurement of water resistance. Instead of using distilled water in the water resistance test, dilute sulfuric acid with a specific gravity of 200
Use m1.

〔Effect of the invention〕

As can be seen from the above examples, it has excellent water resistance and acid resistance, and the difference between working temperature and liquidus temperature is more than iso"c, for example / /
The temperature was 1.0 to 300°C, and the workability was excellent. Furthermore, a glass composition can be obtained at a relatively low cost.

Table 1

Claims (3)

[Claims] (1) The following components expressed in weight%: SiO_2 63.0-67.0 B_2O_3 4.0-4.8 Al_2O_3 4.0-5.5 TiO_2 0-4.0 MgO 2.5-3.6 CaO 4.7-8.7 BaO 0-5.0 Na_2O 7.5-13.9 K_2O 0-2.0 Na_2O+K_2O 8.0-15.5 Fe_2O_3 0-1.0 ZrO_2 0-5.0 , the sum of these components is at least 95% by weight
A glass composition characterized by: (2) The glass composition has a working temperature at least 150°C higher than its liquidus temperature (the viscosity of the glass composition is 10°C).
The glass composition according to claim 1, wherein the glass composition has a temperature of 0.00 poise. (3) The glass composition according to claim 2, wherein the glass composition has a liquidus temperature of at most 1050°C and a working temperature 160 to 300°C higher than the liquidus temperature.