JPH07172863A - Fireproof plate glass - Google Patents

Abstract

PURPOSE:To produce fireproof plate glass having high heat resistance and a moderately low coefft. of thermal expansion, capable of further improving its fire and heat resistances by tempering and excellent in water resistance even with a tank furnace for plate glass. CONSTITUTION:This fireproof plate glass consists of, by weight, 57-66% SiO2, 15-20% Al2O3, 5-8% B2O3, 4-7% MgO, 2-7% ZnO and 2.8-9% Na2O. In this compsn., the weight ratio of Al2O3 to B2O3 is 2.0-4.0.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a window glass for construction, and relates to a fire-resistant plate glass applicable to fire doors, fire windows and the like. Of course, fire resistance and heat resistance are required, and it is also suitable as a glass material for a site that is easily affected by fire heat.

[0002]

2. Description of the Related Art Japanese Patent Publication No. 1-46460 related to the invention of the present applicant relates to a low expansion glass, which is SiO _{2 in} weight%.
55-68%, Al ₂ O ₃ 15-24%, B ₂ O ₃ 2-8%, MgO 3
~ 10%, ZnO 3-10%, and optional BaO, Na
Including ₂ O, (Al ₂ O ₃ + B ₂ O ₃ ) / (MgO + ZnO + BaO + Na ₂ O)
We have proposed a glass that can be applied to a photoetching mask with a specified molar ratio, but it is not a glass that aims for fire resistance and heat resistance, and that it contains an alkaline component (Na ₂ O) as an optional component and that it is 2% or less. Is basically different from the present invention.

[0003] Na ₂ O component is _{Al 2 O 3 -SiO 2 (-ZrO} 2) system reacts with the surface of the refractory brick _{SiO 2 -Al 2 O 3 -Na 2} O system that is employed in ordinary plate glass tank furnace A highly viscous (neferin-based) protective layer is formed, which suppresses erosion of refractory bricks.
Furthermore, by adding ZrO ₂ to the nepheline-based layer, a highly viscous protective layer is formed and the erosion control effect is increased. However, when there is no or a very small amount of Na ₂ O component in the glass, the protective layer is not formed, so that erosion significantly progresses,
In addition to reducing the life of refractory bricks, eroded refractory bricks form so-called gravel and striae, which lowers glass production efficiency. Therefore, in the present invention, it is essential to contain the Na ₂ O component in a specific amount or more.

Japanese Examined Patent Publication No. 55-6588 relates to a fire-resistant glass plate or a glass-ceramic plate, which has heat resistance capable of withstanding a burning test based on DIN.41O2 and has a responsive pressure (for example, by rapid cooling) at the edge. the thermal expansion coefficient α (× 10 ^-7 / ℃) and glass plate or glass ceramic plate product is 1-5 kg / cm ^2. ° C. modulus of elasticity E (Kg / cm ²⁾ is disclosed.

It is speculated that the present invention will be consistent in the value of α × E, but the inventive composition range is inconsistent with any of the disclosed example compositions. Generally, the known example has a high viscosity-melting temperature and a temperature of 1800 ° C for the viscosity required for melt homogenization (approximately 10 ² poise).
It requires before and after, and the evaporation of B ₂ O ₃ becomes more remarkable as the temperature becomes higher, so it is not suitable for glass production using ordinary tank kilns and refractory bricks, whereas the production cost rises significantly, In the present invention, the temperature may be on the order of 1600 ° C. or lower, and it is possible to adopt an ordinary tank kiln or refractory brick.

Japanese Unexamined Patent Publication (Kokai) No. 54-90318 relates to a glass having a high thermal residual stress with high temperature variability, and a thermophysical property such as a transition point, a softening point, a processing temperature, and a thermal expansion coefficient is set in a specific range. , And the composition of ingredients is wt%, SiO ₂ 61.6 to 79.5
%, B ₂ O ₃ 1.0 to 10.5%, Al ₂ O ₃ 2.5 to 14.0%, Na ₂ O 1.
5 to 6.0%, wherein CaO, MgO (3.1% or less), ZnO, and BaO as a selection essential component, the sum is 3.2 to 17.9%, glass containing _{ZrO 2, As 2 O 3,} NaCl is disclosed as optional components ing.

However, the composition of the above components is inconsistent with the present invention in the range of Al ₂ O ₃ and MgO components, and most of Al ₂ O ₃ / B ₂ O ₃ are also seen from the examples disclosed in the known examples. The present invention basically has a different structure from that of the present invention such that the ratios do not match.

The present invention is a glass composition which is rich in fire resistance and heat resistance, resistant to thermal shock, and can be manufactured by a normal plate glass tank kiln and refractory brick, and has a softening point of 850.
Higher than ℃, coefficient of thermal expansion around 35 × 10 ^-7 / ℃ or 60 ×
It is reasonably low at 10 ^-7 / ° C or less, so the coefficient of thermal expansion is 30 × 10 ^-7 /
Unlike Pyrex glass at around ℃ or below, it can be strengthened by air cooling like ordinary plate glass (of course, it can also be strengthened by various cooling media and strengthened by ion exchange), thereby improving fire resistance and heat resistance. It is intended to provide a fire-resistant flat glass which can be further improved.

[0009]

[Means for Solving the Problems] In the present invention, SiO ₂ 57-66%, Al ₂ O ₃ 15-20%, B ₂ O ₃ 5
~ 8%, MgO 4 ~ 7%, ZnO 2 ~ 7%, Na ₂ O
2.8 to 9%, and the weight ratio of Al ₂ O ₃ / B ₂ O ₃ is 2.0 to 4.0.
In the refractory plate glass, the SiO ₂ is TiO ₂ and / or ZrO ₂ in the range of 3% or less, and / or the Na ₂ O is Li in the range of 0.5% or less.
Substituted with ₂ O and / or K ₂ O.

In the present invention, the softening point is 850 ° C. or higher, the heat resistance is excellent, and the expansion coefficient of the glass is about 35 × 10 ⁻⁷ / ° C.
It is moderately lower than 60 × 10 ^-7 / ° C. Therefore, it can be strengthened by air cooling like ordinary plate glass. Of course, it can be easily strengthened by various cooling media and ion exchange, which further improves heat resistance. Yes, and a 10 ² poise temperature of 1600
Well-known borosilicate glass of ℃ order or less
It is much lower than (so-called Pyrex glass), and can be used for ordinary plate glass tank kilns and refractory bricks when manufacturing it, and the water resistance (weight reduction) of glass is comparable to that of borosilicate glass, and that of refractory bricks. This has the effect of suppressing erosion.

In the present invention, SiO ₂ --Al ₂ O ₃ --ZnO--
By using a eutectic system of MgO, it becomes possible to melt at a relatively low liquidus temperature, and by further introducing an appropriate amount of B ₂ O ₃ component, the liquidus temperature is lowered and the thermal expansion coefficient of glass is also lowered. The purpose is to facilitate melting by introducing an appropriate amount of Na ₂ O component and to suppress the erosion of refractory bricks.

In this component system, SiO ₂ is the basic component for forming glass, but when it exceeds 66% by weight, the viscosity of the glass melt increases, and in particular, the homogeneous melting property and the clarification property deteriorate, resulting in 57%.
If it is less than the above range, the tendency of devitrification to crystallize increases, so the range is 57 to 66%, more preferably 59 to 66%. Al ₂ O ₃ at high temperature
Eutectic with SiO ₂ and divalent components to facilitate glass melting,
Also, the molding is easy. Further, it improves the water resistance and chemical resistance of the glass, but if it exceeds 20%, the viscosity will increase and it will be difficult to homogenize the melt. If it is less than 15%, the water resistance and chemical resistance will deteriorate, so it will be 15-20%. The range is.

B ₂ O ₃ acts as a solvent at the time of melting the glass and reduces the coefficient of thermal expansion of the glass, but if it exceeds 8%, the chemical resistance of the glass is rather deteriorated and the heat resistance is deteriorated. However, if it is less than 5%, the action as a solvent is insufficient,
The effect of reducing the coefficient of thermal expansion is also insufficient, so the range is 5-8%.

MgO is essential for suppressing the thermal expansion coefficient of the glass to be low and facilitating the glass formation. However, if it exceeds 7%, durability such as acid resistance of the glass is deteriorated, and if it is less than 4%, melting of glass does not occur. Since it deteriorates the clarification homogeneity, it is 4 to 7%. ZnO is also effective in relatively suppressing the coefficient of thermal expansion of glass, lowering the high temperature viscosity during melting, and improving the chemical durability of the glass, but if it exceeds 7%, devitrification crystals occur. 2%
If it is less than 2, it is difficult for the above-mentioned functions to work effectively, so 2 to 7
The range is%.

Na ₂ O is a strong solvent in melting glass, facilitates melting of glass, and reacts with refractory bricks as described above to form a protective layer on the brick surface to prevent erosion of refractory bricks. It is essential to suppress and maintain the brick life for a long time, but if it is less than 2.8%, its action is insufficient, and if it exceeds 4%, the coefficient of thermal expansion of glass tends to gradually increase, but if it is 9% or less, It is moderately low, around 60 x 10 ^-7 / ° C or less, and can be strengthened by air cooling like ordinary plate glass. Of course, it can be strengthened by various cooling media and strengthened by ion exchange, which further increases fire resistance and heat resistance. Can be improved. In particular, the point of forming a protective layer on the brick surface,
Considering the point of facilitating the strengthening treatment, it is preferably introduced in the range of 5 to 9%.

Further, the weight ratio of Al ₂ O ₃ / B ₂ O ₃ is 2.0 to 4.0.
It is introduced in the range of 2.0, and by setting it to 2.0 or more, it is possible to eliminate the phase separation at the time of glass melting and molding, the tendency of clouding, and to set it to 4.0 or less, the rise of the liquidus temperature during glass melting,
The tendency of poor solubility can be suppressed. More preferably, the range is 2.0 to 3.0.

In addition, SiO₂Replaced with TiO₂, ZrO₂Less than 3%
Introduced in the range, Na₂Replace with O, Li ₂OK₂O less than 0.5%
It can be introduced in the range below. Note that CaO and PbO
The introduction increases the coefficient of thermal expansion of the glass and deteriorates the water resistance etc.
It is not preferable due to reasons such as making it possible.

Furthermore, if a small amount of BaO component is introduced in the form of nitrate or sulfate, it is effective in eliminating bubbles during melting and homogenizing, or if a small amount of As ₂ O ₃ , Sb ₂ O ₃ or the like known as a fining agent is added. I do not support adding any amount.

[0019]

The present invention will be described in detail below with reference to examples. Quartz sand as [Sample preparation] SiO ₂ source, aluminum hydroxide as Al ₂ O ₃ source, boric acid as B ₂ O ₃ source, magnesium carbonate as MgO source, a zinc oxide as a ZnO source, Na ₂ O source sodium carbonate as a lithium carbonate as Li ₂ O source, the Anateze (TiO ₂₎ as a TiO ₂ source, was used zircon sand as ZrO ₂ source.

These raw materials were weighed and mixed according to the compositions of Examples 1 to 17 shown in Table 1, and in each case, arsenous acid as a fining agent was added and mixed within a range of 0.5 g or less with respect to 100 g of glass. , Platinum crucible, filled in a resistance heating electric furnace at 1550 ~ 1650 ℃, held for 4 ~ 5 hours, melted, then cast the glass onto a carbon plate,
Further, the glass was gradually cooled in an electric furnace to obtain a sample.

In Comparative Examples 1 to 4, the glass manufactured by Central Glass Co., Ltd. or a commercially available glass was used as it was, and the composition was analyzed by wet analysis. The component composition is shown in Table 1.

[0022]

[Table 1]

[Test] The glass sample is appropriately cut out, and the coefficient of thermal expansion, the transition point, and the yield point are measured by an dilatometer by a conventional method.
The viscometer measured the Lyttelton point (softening point) and the high temperature viscosities of major samples. Further, the amount of Na ₂ O eluted (/ 5g glass) was measured by an alkali elution test based on JIS R-3501, and the weight loss (%) at that time was measured.

Further, a brick erosion test was carried out on main samples, and Al ₂ O ₃ which is usually used in a tank kiln for producing plate glass was used.
Cut -SiO ₂ -ZrO ₂ system bricks into a rod, which was used as a sample to be inspected.

After filling the glass sample in the platinum crucible
Place in an electric furnace with 10 of each glass ²Temperature near the poise
 (1550 ℃ ~ 1650 ℃ in the example, in Comparative Example 1
Is 1450 ° C, and in Comparative Example 3 and Comparative Example 4 is 1600 ° C,
In Comparative Example 2, 10²Because the poise temperature is too high
The sample to be inspected in the melted glass
Is set upright and held at that temperature for 72 hours.
After taking out the brick piece and making a thin piece of the interface part,
Brick erosion, reaction layer (neferi
The generation status of Comparison of formation of nepheline layer
◎, the nepheline layer is confirmed to a lesser degree
Those that can be worn are ○, those that do not reach layer formation are △, and nephew
When the formation of phosphorus was hardly recognized, it was evaluated by x, and
Brick erosion is minimal ◎, erosion is less than the above
With a small amount of ∘, those with obvious erosion are △, and marked
Was evaluated by x.

The results are summarized in Table 1. In the high temperature viscosity, the temperature at which the viscosity shows 10 ² poise is displayed.

[Results] In Table 1, Examples 1 to 17 relate to the present invention, Comparative Examples 1 and 4 show soda-lime-silica float glass manufactured by Central Glass Co., Ltd., and photomask glass, respectively. Example 2 and Comparative Example 3 are commercially available borosilicate (Pyrex) glass and aluminoborosilicate (Supremax) glass.

In the brick erosion test of Comparative Example 2,
(Indicated by * in Table 1), a temperature of 1850 ° C. or higher is required to obtain 10 ² poise, and the temperature cannot be obtained with an ordinary electric furnace, so the test was abandoned. By the way, when the test was conducted at 1650 ° C, no trace of erosion or reaction was observed because of high glass viscosity and lack of fluidity and reactivity.

In this embodiment, the softening point is 850 ° C. or higher, the heat resistance is high, and the expansion coefficient is about 35 × 10 ⁻⁷ / ° C. or 60 × 10 6.
^It is moderately low at ^-7 / ℃ or less, so it can be strengthened by ordinary strengthening means, which can further improve the heat resistance and the water resistance (weight reduction) is in the range of 0.01% to 0.03%. Compared with silicate glass, it has a poise temperature of 10 ²
It is much lower than the known borosilicate glass with the order of 1600 ° C or less, rather close to the temperature of soda lime glass, and the action of suppressing the erosion of refractory bricks by forming a nepheline layer in the brick erosion test Produce an effect. In particular, the effects are remarkable in Examples 2, 4, and 5.

Although Comparative Example 1 does not have fire resistance and heat resistance as a matter of course, it is shown for reference. Comparative Example 2 has a high 10 ² poise temperature as described above, requires a corresponding melting temperature, and B ₂ O ₃ also volatilizes remarkably, so a special melting kiln made of a special refractory brick is required, which is inevitable. Moreover, the manufacturing cost is soaring and the production efficiency is poor.

Since Comparative Example 3 had a small amount of Na ₂ O, no reaction product (nepheline) was observed in the brick erosion test, and Comparative Example 4 had a small amount of Na ₂ O, but the reaction product was generated. In all cases, the erosion of bricks was obvious or remarkable, even though the protective layer was not formed.

[0032]

EFFECT OF THE INVENTION In the present invention, the softening point is 850 ° C. or higher, the heat resistance is excellent, and the expansion coefficient is about 35 × 10 ⁻⁷ / ° C. to 60 × 10 5.
^It is relatively low at ^-7 / ℃ or less, so it can be strengthened by ordinary strengthening means, which can further improve the heat resistance and the water resistance (weight reduction) is in the range of 0.01% to 0.03%. Compared with silicate glass, it has a poise temperature of 10 ²
It is significantly lower than the known borosilicate glass, which is in the range of 1600 ° C. or lower, and has the effect of suppressing the erosion of refractory bricks by forming a nepheline layer in the brick erosion test.

Claims (2)

[Claims] 1. In weight% display, SiO ₂ 57-66%, Al ₂ O ₃ 15-20%, B ₂ O ₃ 5-8%, MgO 4-7%, ZnO 2-7%, Na ₂ O 2.8 to 9%, and the weight ratio of Al ₂ O ₃ / B ₂ O ₃ is 2.0.
Fire-resistant flat glass characterized by being ~ 4.0. 2. SiO ₂ in the range of 3% or less to TiO ₂ and / or ZrO ₂ , and / or Na ₂ O in the range of 0.5% or less to Li.
The refractory plate glass according to claim 1, which is substituted with ₂ O and / or K ₂ O.