JPH09208246A - Fireproof glass - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the problem that a glass sheet is corrugated, waved and distorted and the basic performance as the glass sheet for a see-through window is deteriorated by heating the sheet close to the softening point and excessively toughening the sheet with more severe air blowing or other quenching means. SOLUTION: A soda-lime glass is heated above the annealing point, quenched and thermally tempered to obtain the fireproof glass. In this case, in the thermal tempering, the sheet is heated above or below the temp. corresponding to the viscosity of 10<9> poise and quenched with air blowing to prepare the fireproof glass having 1700-2400kg/cm<2> surface compressive stress.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glass plate applied to an opening such as a door or a window of a building, etc., and when a fire is encountered, the flame is shut off and the transparency is maintained to extinguish the fire. The present invention relates to a fireproof glass that can be applied as a so-called type B fire door without hindering activities.

[0002]

2. Description of the Related Art When a fire is encountered, the glass plate for an opening that suppresses the flame from penetrating and spreading the fire is specified by the fire door heating test method specified in Ministry of Construction Notification No. 2999 in 1969. It is necessary to heat for a certain period of time and satisfy the flame shielding performance, smoke shielding performance, and structural stability performance specified in the Ministry of Construction Notification No. 1125, 1990. Various proposals have heretofore been made for such a glass plate, that is, a glass plate that can be suitably used as a type A or type B fire door.

For example, there have been examples of proposing borosilicate glass, lithium-containing silicate glass, or transparent crystallized glass having a low coefficient of thermal expansion and a high softening point, but they have a very special composition and are highly manufactured at high temperatures. It requires technology, is expensive, and has difficulty in widespread use.

In addition, a double-glazing type fireproof glass in which an aqueous gel is sandwiched between a pair of glass plates has also been proposed, and when heating by a fire, thermal insulation by foaming of the aqueous gel can prevent the advance of flames. It is said to be possible.
This is excellent in that it prevents overheating of the heated side by the thermal insulation effect, complicated process in manufacturing it, requires advanced technology, the cost is also great, the overall thickness is thick, If the size is large, the weight is increased and the handling is not easy, and it is difficult to be widely adopted because the foaming of the aqueous gel upon heating impairs the transparency and interferes with the fire extinguishing activity.

To solve the problems of these known techniques
No. 58-52929 discloses a fire-proof window glass plate, which is a soda-lime glass plate heat-treated almost uniformly over the entire surface and has a surface compressive stress of 26 kg / mm ² or more.

[0006]

However, the above disclosed example is
By heating the glass plate to near the softening point and using stricter air blasting or other quenching means to force excessive strengthening, defects such as waves, undulations, and distortion occur in the glass plate, and glass plates for transparent windows. As a result, the basic function as is impaired.

The present invention solves the above problems, and provides a fireproof glass which is relatively easy to strengthen, has a desired fireproof performance, and does not cause defects such as upper air strain.

[0008]

DISCLOSURE OF THE INVENTION The present invention is a fireproof glass obtained by a heat strengthening treatment in which a soda-lime glass plate is heated to a temperature above an annealing point and tempered by rapid cooling. By heating to a temperature equivalent to 10 ⁹ poise or below, and quenching by air blasting, the surface compressive stress of the glass plate becomes 17
Fireproof glass prepared to be in the range of 00 to 2400 Kg / cm ² , the glass plate in the fireproof glass being a float glass, or a polished glass plate obtained by a mechanical polishing method, the float method, or the mechanical polishing method. However, the composition of the polished plate glass is SiO ₂ 68 to 71 wt%, Al ₂ O ₃ 1.6 to 3 wt%, CaO 8.5 to 11 wt%, MgO 2 to 4 wt%, Na ₂ O 12.5 to 16 wt%, K ₂ O 0.9 to 3 wt%, the sum of the above is 97 wt% or more, and SiO ₂ + Al ₂ O ₃ 70 to
73 wt%, CaO + MgO 12-15 wt%, Na20 + K20
13.5 to 17 wt%, further, the glass plate was polished and finished over the entire circumference of the edge prior to the heat strengthening treatment, and the maximum roughness of the polished and finished portion at the edge of the glass plate was set to 20 μm or less. In addition, both surfaces of the glass plate are coated with a heat ray reflective substance.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, ordinary soda lime type glass can be used for the glass base plate, and the manufacturing method thereof can employ a float method, a lifting method, a mechanical polishing method or other known manufacturing and plate manufacturing means. .

[0010] It is preferable to use a float glass plate having a smooth surface with few surface defects and distortions, and more preferably, a polished glass plate having both surfaces simultaneously polished by a mechanical polishing method to suppress warpage, waves, and plate thickness fluctuations. It is desirable to do.

Although the composition range of ordinary clear soda-lime glass is not specified, it is roughly in the following range, that is, SiO ₂ 70 wt% order,
Al ₂ O ₃ around 0-2 wt%, CaO + MgO 10-20 wt%
(Typically MgO is included before and after _{4wt%), Na 2 0 +} K 2 0 10~
20 wt% (usually Na ₂ O is contained at about 13 wt% or less), and a small amount of Fe ₂ O ₃ , TiO ₂ , SO _{3 and the} like.

On the other hand, the applicant of the present invention has proposed a so-called easily tempered glass composition in which the composition range is limited with respect to the above-mentioned composition as a glass which is particularly easily tempered (Japanese Patent Application No. 61-
No. 87196), the use of the composition is advantageous because it has excellent melt moldability and weather resistance. The composition of the components is as follows: SiO ₂ 68 to 71 wt%, Al ₂ O ₃ 1.6 to 3 wt%, CaO 8.5 to 11 wt%, MgO 2 to 4 wt%, Na ₂ O 12.5 to 16 wt%. %, K ₂ O 0.9 to 3 wt%, the sum of the above is 97 wt% or more, and SiO ₂ + Al ₂ O ₃ 70 to
73 wt%, CaO + MgO 12-15 wt%, Na ₂₀ + K ₂₀
13.5 to 17 wt%.

The glass plate is preferably colorless transparent glass,
Not limited to this, a colored transparent glass plate such as blue, gray, green or bronze may be used.

The size of the glass plate is not specified, and various sizes can be adopted within the range of sizes that can be processed by the heat strengthening treatment means, and are usually appropriately selected within the range of several hundred mm □ to several thousand mm □. it can.

Needless to say, the higher the thickness of the glass plate, the easier the heat strengthening treatment, but the heat strengthening treatment is possible from a thickness of about 10 mm to 6 mm or around that. is there. Considering handling workability, it is around 6 mm to 8 mm
It is preferable to use the front and rear ones.

Although the heat strengthening treatment means is not specified, for example, in a device for heat strengthening while holding a glass plate in a vertical state, a local concave trace is formed on the glass plate due to the glass plate suspension means, It is not preferable because it impairs the uniformity of reinforcement. On the other hand, a so-called horizontal reinforcing device such as a gas hearth or a roller hearth can be preferably used because such an adverse effect can be eliminated.

By grinding and polishing the edge portion of the glass plate prior to heat strengthening, it is possible to prevent the occurrence of cracks from this portion, which is likely to be the starting point, as much as possible, and it is stable with little variation. It is possible to obtain fireproof performance with good reproducibility.

FIG. 1 shows a sectional view of the edge of a glass plate ground and polished. For example, the angle θ formed between the surface of the glass plate 1 and the oblique section X is 30 to 60 °, and the oblique section X Width C is 1
The edge is ground and polished to have a thickness of about 3 mm. In this case, the maximum roughness of the wood end face and the yarn face is set to 20 μm or less, and if it exceeds the above upper limit, cracks originating from the portion tend to occur during heating. More preferably, the thickness is 10 μm or less. It should be noted that the lower limit of the maximum roughness is not limited, but it cannot be said that it is a good idea because even if it is polished to about 2 μm or less, the fireproof performance cannot be improved and the processing cost is rather increased.

Alternatively, the end surface may be arcuate, that is, a so-called semi-circular shape, and the maximum roughness of the arcuate end surface is 20 μm or less, more preferably 10 μm or less for the same reason as above. However, considering the ease of processing, the above-described thread chamfering is easier, and defects such as polishing scratches that hinder fire protection performance do not occur.

Further, by coating a heat ray reflective film on both sides of the glass plate, that is, a metal oxide film called a heat ray reflective film, a low emissivity film, a metal film, or a laminated film thereof, radiant heat is effectively applied. It is possible to suppress a remarkable temperature rise of the glass plate itself during the heating. The temperature difference between the center of the glass plate and the end face reaches the maximum in 10 to 13 minutes after heating, and exceeds 350 ° C without the heat ray reflective film, but 270 to 300 ° C for those coated with the heat ray reflective film. Below, the heating resistance of the glass plate can be improved accordingly.

In the heat strengthening treatment of the soda-lime glass plate, the glass plate has a viscosity at a temperature corresponding to 10 ⁹ poises,
Alternatively, heating to a temperature lower than that is essential. Although the temperature varies slightly depending on the composition of soda-lime glass, it is approximately 650 ° C for ordinary soda-lime glass.
Or 660 ℃. When the glass plate has a viscosity lower than 10 ⁹ poise, that is, a higher heating temperature, the glass plate is excessively softened, and distortions such as waves and waviness on the plate surface during air blasting tend to be conspicuous. The upper limit of the viscosity upon heat strengthening is not specified, but it is about 10 ¹⁰ poise and the heating temperature is about 620 ° C. to 630 ° C. Above that, it is difficult to obtain the desired surface compressive stress in the glass plate.
In addition, in the easily strengthened composition, a desired surface compressive stress can be obtained at a lower temperature, and accordingly, strengthening becomes easier.

In air blasting, even if the cold air pressure is increased, the surface compressive stress of the glass plate is not improved linearly, and a more remarkable cold air pressure is required to obtain a high surface compressive stress.

Taking these heat strengthening treatment conditions into consideration, in actual operation, the heating temperature of the glass plate is a temperature at which the viscosity of the glass is equivalent to 10 ⁹ poise or lower, and the surface compressive stress of the glass plate is reduced. Is appropriately 2400 Kg / cm ² or less. If the surface compressive stress is less than 1700 kg / cm ^2, it is difficult to recommend it for Class B fire doors, considering fire resistance stability and reproducibility.

The fireproof glass thus obtained will have impaired fireproof performance if the surface or end face thereof is damaged during transportation, storage or construction. Therefore, it is desirable to protect the surface and the end surface. Regarding the protection of the surface, there is a concern that scratches will occur when glass plates are stacked on top of each other, but the usual practice is to insert interleaving paper, intervene with powder spacers, or even apply an organic film to the plate surface. By taking measures such as wearing (called a curing film in the industry),
The board surface can be protected.

Particularly for protection of the end face which is apt to be scratched by contact with peripheral articles and equipment, resin tape (including mixture of inorganic powder and metal powder) on the end face, inorganic tape
(For example, glass cloth tape, inorganic fiber braided tape such as carbon fiber tape, etc.), metallic tape (for example, aluminum tape, steel tape, zinc tape, their perforated tape, fine wire braided tape, etc.) The end face can be easily protected by wrapping, application of a resin-based or inorganic-based paint similar to the above, end face coating layer forming means called so-called encapsulation, or the like.

The fireproof glass produced in this manner is
Although it can be used as a single plate as it is, as a double glazing or a laminated glass, for example, one glass plate as a glass plate in the present invention, the other glass plate is a normal glass plate, or a glass plate by a conventional tempering method. Alternatively, the glass plate in the present invention may be used. When the laminated glass is used, it is preferable to adopt a heat-resistant and fire-resistant intermediate film such as polymetallosiloxane.

Further, in the double glazing including the glass plate of the present invention, it is useful as a heat-insulating fireproof glass by incorporating a known water-based gel or a vaporizable material in the inner space thereof.

[0028]

[Example 1] -Example of fireproof glass having a normal glass composition- [Production of fireproof glass sample] Size 610 mm □ × 8 mm (thickness),
And a large number of ordinary soda-lime colorless transparent glass plates made by two types of float methods with different plate thicknesses of 610 mm □ × 6 mm (thickness), the peripheral edge of which is shown in Fig. 1 with a double edger. Grinded and polished. The width t of the thread surface is 2 mm, and the abrasive grain size is variously changed. Polisher finish is applied over the thread surface and the wood end surface (the maximum glass surface roughness is several μm).
Or 20 μm).

The glass composition is as follows: SiO ₂ 71.6 wt%, Al ₂ O ₃ 2.0 wt%, Fe ₂ O ₃ 0.1 wt%, CaO 8.3 wt%, MgO 3.7 wt%, Na ₂ O 12.9 wt% , K ₂ O 1.1 wt%.

Next, this was put into a roller hearth furnace,
After maintaining the glass plate at various set temperatures in the heating zone, cooling air is jetted at a set pressure (wind pressure) from a number of blast heads arranged close to the glass plate in the air cooling zone to quench and strengthen the glass plate. , A fireproof glass sample.

With respect to a part of the glass plate which has been subjected to the above treatment, the total film thickness is 400
A heat ray reflective film obtained by sequentially laminating stainless steel of A and titanium nitride was coated to obtain a fireproof glass sample.

These fireproof glass samples were subjected to surface compression stress (FSM-30 manufactured by Toshiba Glass Co., Ltd.) by a known refractometer method.
Using a surface stress meter (using a Na lamp light source) was measured.

The above-mentioned various conditions and results, that is, the thickness of the fire-proof glass sample, the maximum roughness of the edge portions (thread surface and wood edge surface), the heat strengthening conditions (the sample temperature when passing through the heating zone of the roller hearth furnace, the cold air pressure at the blast head) ) Etc. and the measurement results of the surface compressive stress are shown in Table 1.

[Various Tests] (Strain Inspection) Each fireproof glass sample was subjected to a strain inspection by a known zebra board method. In other words, it is a distortion inspection method in which a zebra board is reflected on the glass plate surface and the reflected image is visually observed, and it is judged based on a normal normal glass plate, and a normal glass plate is good, but it can be used although it is inferior to the above = Yes,
The distortion is so severe that it is difficult to use = impossible.

(Fire Protection Test) Each glass sample was heated for 20 minutes according to the heating temperature curve of the furnace shown in the attached FIG. 2 based on the fire door heating test method specified in Ministry of Construction Notification No. 2999 in 1969, and constructed in 1990. Tests were conducted for flame barrier performance, smoke barrier performance, and structural stability performance specified in Ministry Notification No. 1125. The heating for 20 minutes is applied to Class B fire doors.

The fireproof glass sample has a margin of 8 mm between steel angles, and is supported and fixed by a ceramic wool backup material and a silicone sealing material around the edge area of the sample, and the sample end surface by a calcium silicate setting block. .

FIG. 3 is a partial side sectional view of the heating test furnace.
Fireproof glass sample (glass plate) at the opening of the heating test furnace 2 1
Are arranged as shown in the figure and subjected to a heating test. Then, after heating for 20 minutes as described above, after heating, check for the presence of flame on the back side (outside of the furnace), the presence of gaps and cracks on the heating surface, and the presence of smoke on the back side during heating. After observing with the naked eye, after heating, a sand bag weighing 3 kg (indicated by reference numeral 3 in Fig. 3) suspended by a rope from above the back side of the fireproof glass sample was dropped from a height of 50 cm in vertical direction and shocked. Then, the sample was visually inspected to see if it was broken or dropped. These results are shown in Table 2.

For some fireproof glass samples, the temperatures of the front and back surfaces of the central portion of the glass plate and the end surface temperature were measured. Temperature of the center of the glass plate for some of the samples
Table 2 also shows the heating temperature (minutes) when the temperature difference between the (average temperature of the front and back surfaces) and the end surface temperature became the maximum, and the temperature difference.

[Results] The fire-resistant glass sample No. 1 has a low surface compressive stress and cracks and breaks occur within 10 minutes after the start of heating, and cannot be applied as a fire-resistant glass.

Sample No. 11 has a high heating temperature and a surface compressive stress of more than 2400 kg / cm ^2, which is not a problem in terms of fire prevention performance, but is extremely difficult to use due to its strain. Samples Nos. 2 to 10 and Nos. 12 to 14 were judged to be good or acceptable in the strain test, and were also good in the fireproof test, and are suitable as fireproof glass. As shown, the heat ray reflective film (stainless steel
The maximum temperature difference between the glass with and without the glass)
(The largest value of the difference between the central temperature and the edge temperature of the glass plate) is much lower than the maximum temperature difference of the latter, so it is clear that the fireproof performance can be imparted by laminating the coating on the glass. .

[0041]

[Table 1]

[0042]

[Table 2]

[0043]

[Example 2] -Example of fireproof glass composed of easily tempered glass composition- [Production of fireproof glass sample] Size 610 mm □ × 8 mm (thickness),
And 610 mm □ × 6 mm (thickness), two types of glass plates with different plate thickness, which are soda-lime colorless that are easily strengthened by mechanical plate-making and plate-making (both sides simultaneous polishing: so-called duplex method). A large number of transparent glass plates were prepared.

The glass composition is as follows. ---- A
Composition SiO ₂ 70.4 wt%, Al ₂ O ₃ 2.0 wt%, Fe ₂ O ₃ 0.1 wt%, CaO 11.0 wt%, MgO 2.0 wt%, Na ₂ O 13.2 wt%, K ₂ O 1.1 wt%.

The following compositions were used for some of the samples. ---- B composition SiO ₂ 69.5 wt%, Al ₂ O ₃ 2.0 wt%, Fe ₂ O ₃ 0.1 wt%, CaO 10.5 wt%, MgO 2.5 wt%, Na ₂ O 13.5 wt%, K ₂ O 1.0 wt %.

The waves and undulations on the surface of the base plate obtained by the duplex method are extremely small, and the flatness is higher than that of the float plate glass.

The peripheral portion of the above sample was ground and polished in the same manner as in Example 1. The width t of the thread surface is 2 mm, and the abrasive grain size is variously changed. Polisher finish is applied from the thread surface to the wood end surface (the maximum glass surface roughness is several μm to 20 μm).
) did.

Next, these are put into a roller hearth furnace, and the temperature of the glass plate is maintained at various set temperatures in the heating zone, and then cooling air is supplied from a large number of blast heads arranged close to the glass plate in the air cooling zone. A fireproof glass sample was prepared by injecting at a set pressure (wind pressure) to quench and strengthen the glass plate.

The surface compressive stress of each of the fireproof glass samples was measured by a refractometer method similar to that of Example 1 (using FSM-50BR: He-Ne gas laser manufactured by Toshiba Glass Co., Ltd. as a light source).

The above-mentioned various conditions and results, that is, the thickness of the fireproof glass sample, the maximum roughness of the edge portions (thread surface and wood edge surface), the heat strengthening condition (the sample temperature when passing through the heating zone of the roller hearth furnace, the cold air pressure at the blast head) ) Etc. and the measurement results of surface compressive stress are shown in Table 3.

[Various Tests] (Strain Inspection) Strain inspection was performed and evaluated by the same zebra board method as in Example 1. The results are shown in Table 3.

(Fireproof Test) A heating test was performed based on the same fire door heating test method as in Example 1, and the same evaluation as in Example 1 was performed.
The results are shown in Table 4.

[Results] Fireproof glass samples NO.1a to NO.6a prepared by mechanical polishing and using a glass plate having an easily strengthened composition as a raw glass were easily strengthened and mechanically polished. Due to the fact that the plate surface was preliminarily flattened by the above method and the glass having an easily tempered composition having a high coefficient of thermal expansion and a low coefficient of thermal conductivity was adopted, the glass plate temperature at the time of heat treatment strengthening was the glass of Example 1. 5 of that
Since it can be performed at a low temperature of ℃ or more, the strain such as waves and undulations on the plate surface after strengthening is lower than that of the fireproof glass of Example 1.

[0054]

[Table 3]

[0055]

[Table 4]

[0056]

EFFECTS OF THE INVENTION According to the present invention, it is possible to strengthen relatively easily, have desired fireproof performance as a type B fire door, and prevent defects such as distortion from occurring.

[Brief description of drawings]

FIG. 1 is a partial side sectional view of a glass plate.

FIG. 2 shows a heating temperature curve of a heating test furnace in a heating test.

FIG. 3 is a partial side sectional view of a heating test furnace.

[Explanation of symbols]

 1 ---- Glass plate (Fireproof glass sample) .2 ---- Heating test furnace

Claims (6)

[Claims] 1. A fireproof glass which is obtained by a heat strengthening treatment in which a soda-lime glass plate is heated to a gradual cooling point or higher and tempered by quenching, and the viscosity of the glass plate during the heat strengthening is
Heat to a temperature equivalent to 10 ⁹ poise or less,
A fireproof glass characterized by being prepared by quenching by air blasting so that the surface compressive stress of the glass plate is in the range of 1700 to 2400 Kg / cm ² . 2. The fireproof glass according to claim 1, wherein the glass plate is a polished glass plate obtained by a float method or a mechanical polishing method. 3. The composition of polished plate glass according to the float method or the mechanical polishing method is SiO ₂ 68 to 71 wt%, Al ₂ O ₃ 1.6 to 3 wt%, CaO 8.5 to 11 wt%, MgO 2 to 4 wt%, Na ₂ O 12.5 to 16 wt%, K ₂ O 0.9 to 3 wt%, the sum of the above is 97 wt% or more, and SiO ₂ + Al ₂ O ₃ 70 to
73 wt%, CaO + MgO 12-15 wt%, Na ₂₀ + K ₂₀
The fire protection glass according to claim 2, wherein the fire protection glass comprises 13.5 to 17 wt%. 4. The fireproof glass according to claim 1, 2 or 3, wherein the glass plate is polished and finished along the entire circumference of the edge portion prior to the heat strengthening treatment. 5. The fireproof glass according to claim 4, wherein the maximum roughness of the polished finish portion at the edge of the glass plate is 20 μm or less. 6. The fireproof glass according to claim 1, wherein both sides of the glass plate are coated with a heat ray reflective substance.