Fire resistant glass

The invention relates to refractory glass.

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An important aspect when designing buildings, especially office and residential buildings, is to prevent fire escalation. Currently, there are basically three types of refractory glass products used in the construction industry. The first group is glass which is embedded or laminated with a wire mesh or other refractory material which naturally reduces the transparency of such glass. While this type of glass breaks easily when exposed to heat or flame, the refractory material associated with the glass (such as a wire mesh) prevents the spread of fire by holding the glass in place.

Another disadvantage of this first group of glass products is that it does not prevent the transfer of heat by radiation to the area behind the glass.

The second group of refractory glass products includes clean glasses which are capable of withstanding, without fracture for at least half an hour, the intense heat applied to them, in accordance with the test described in BS 476, Part 20, 22 or elsewhere; such glasses are heat resistant up to 900 ° C. Although this type of glass prevents the spread of the flame, it cannot prevent the heat from spreading to the area behind the glass.

Glass of the third group of refractory glasses will not break for at least half an hour if exposed to heat / intensive as defined in BS 476 and can also prevent the transmission of strong / intense / heat to the area behind the glass. This glass product is currently made of several layers of glass and other materials.

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is produced from a layer and this combination prevents heat conduction. This third type of glass (the laminate cut laminate glass product) is usually expensive and difficult. Although first class glass is significantly cheaper than this third type, its aesthetic quality is usually unsatisfactory. The second group of glasses has good fire resistance without necessarily being very expensive, while still having an aesthetic quality.

There are currently two refractory products in the second category. One of these is a borosilicate glass board, borosilicate glass is inherently relatively refractory but cannot be sufficiently heat-hardened by heat treatment and thus does not meet certain safety glass requirements such as 62Ο6Λ. contains British Standard. Another problem is that borosilicate glass is much more expensive than standard quartz glass. Another available glass in the second group is a purely ceramic-based product, which, while having excellent fire resistance, is of very poor optical quality and is not an easy substitute for a regular window or pane.

It would be highly advantageous to have a second type of refractory glass product as described above, which is made of ordinary quartz-based glass, but at the same time is relatively inexpensive and has excellent optical properties. However, quartz-based glass by itself is not refractory: it is broken when exposed to strong heat. A further problem is that hardening / hardening of the glass / heat treatment / hardening does not significantly affect its fire resistance properties; break when strong / intense /

Λ is exposed to heat.

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We have found that the second type of refractory product described above can be made from quartz-based cavity by taking appropriate measures, and we have developed a glass that can be used advantageously in the building industry, especially for glazing of buildings where it is desirable or necessary to prevent rapid spread of fire; at the same time, the glass is the so-called. has the same appearance as the coated standard glass. We have developed a method by which this type of refractory glass can be produced relatively simply and economically.

Λ According to the invention, refractory glass is characterized in that it is heat-cured and has a thin layer of chemical applied directly on at least one of its large / main surfaces, which is stable at a temperature below 900 ° C and adheres to the surface. the laminated glass pane does not break until a temperature of 900 ° C is reached; and that the edges of the glass sheet are polished prior to the heat treatment operation to remove imperfections.

The invention also relates to a method of applying a thin layer of chemical substance to one or both of the large / main surfaces of a glass sheet, which is stable to 900 900 and adheres to the surface of the glass sheet; sanding and polishing the edges of the glass sheet and before or after applying the layer (s), the glass is cured / hardened / made tough; and making the laminated glass sheet heat-resistant to these temperatures until the temperature to which it is exposed reaches 900 ° C.

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The present invention also relates to a refractory structural unit having a refractory glass sheet 3/311 enclosed in a refractory steel large wooden frame, coated with a refractory glazing material with a high degree of material, and whose structural glass pane is clean and unbroken. transparent.

Numerous suggestions have become known in the art for applying layers of material to glass panes. Apart from the well known application of / light / filter layers and the like, the formation of metal-containing strands on a glass surface is also known. GB- / 5-1524650. British Patent Specification No. 4,198, heat-treated / toughened / glass panes contain an electrically conductive and heat-reflecting tin oxide film on both sides; such a product is used for glazing stove door windows. Double-sided laminated glass has infrared reflectivity. However, this type of glass cannot be used as a refractory product because it breaks if it is cured for approx. It is exposed to a temperature of 900 ° C. The heat reflectance is not the same as the heat resistance: a glass pane may have a very high heat reflectivity due to the presence of a metal-based heat-reflecting layer, but it has little or no fire resistance.

GB-4-1565765. According to the process of the present invention, a tin oxide film is applied to a glass surface by pyrolizing an organic tin and suspending the powder in a carrier gas formed by a gaseous fluorine compound. 4 as mentioned above in GB.4-1524650. The metal-based layer of the solution according to the invention, this tin oxide film also provides some protection against heat by reflecting the infrared rays, but the glass with the layer is not suitable for use as refractory glass in buildings because it tends to break under intense heat no longer inhibits the spread of fire.

A JP-A-57205343. According to Japanese Patent Specification No. 3,900, the surface treatment of glass improves its optical properties when used in solar cells, liquid crystals, lasers, etc. The glass surfaces are abrasive-polished in oil, then heat-treated and immersed in molten KNOY to effect ion exchange. Subsequently, an indium oxide film can be applied. Thus, the production of a layer of gel-coated glass is extremely expensive and not suitable for use as refractory glass in buildings.

To ensure fire resistance, it is a requirement that the panes remain intact and do not fall apart when exposed to high / intense / heat effects due to fire in the vicinity. This is the precondition for preventing the physical spread of fire. It has been found that the use of a particularly novel combination of three criteria for a quartz-based glass pane will have excellent fire resistance properties. If only one of the three criteria is omitted, this excellent fire resistance will not come. created.

The glazing panel according to the invention is clearly and uninterrupted because the cover layer is thin and has low visible reflection. That is, we have solved the problem of how to make a glass sheet refractory without significantly reducing the purity of the transparency. The result was achieved using a relatively simple procedure such as: • 4

7 that one or both sides of the glass sheet were covered with a thin transparent layer as defined above to satisfy two important requirements, namely that the edges of the glass sheet were polished and that the glass sheet was heat treated / hardened / toughened.

The nature of the glass itself is not critical, but it is preferable to use conventional / i.e., quartz-based / glass, which is manufactured by a well-known patented float line process and generally used for internal and commercial applications. Kern is also critical of the thickness of the glass pane. Typically, glass sheets having a thickness of 6 mm are used, but glass sheets of different thicknesses may be used in the present invention. The glass is cut using a standardized technique. The glass is heat-treated, that is, tempered / solidified, preferably according to British Standard BS 62O6a, that is, in a standard manner. During the solidification / suction process, the glass is heat treated in an oven and subjected to the cycle time required to first heat the glass to 615 ° C to 64 ° C and then rapidly cool it. This heat treatment / solidification / suction / process is known per se and does not require further explanation in this specification. This creates a stress pattern in the product and thus results in a break pattern that meets the requirements of British Standard BS 6206a. British Standard 6206 ^ specifies the impact / impact / resistance requirements for flat glass and safety plastic sheeting used in buildings. For further details, reference is made to this publication.

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- 8 .The edges of the glass plate have been polished to ensure that the imperfections, defects, such as shells and chips, ie chafing, fragmentation, etc., are eliminated. We have found that this is a critically important step without which the bar will break if exposed to higher temperatures. Therefore, it is very important to remove the peripheral defects and imperfections from the board stroke, and this operation is performed prior to the heat treatment / hardening process step.

It is known that, prior to hardening / screening of the bar with heat treatment, rough grinding is performed on the edges of the bar to eliminate relatively large irregularities. This statement is called edge-arrissing. The amount of such grinding is small; much smaller than that required by the process of the invention. According to a preferred aspect of the invention, the edges are even polished after grinding. Usually, bar flanges are routinely sanded just to achieve either a decorative effect or to make the flanges as safe as possible to keep them free / uncovered in the brick product.

According to the invention, grinding can be performed, for example, by using a diamond-coated disk and polishing, for example, by using a fiber-coated disk. Because of the importance of removing any rim imperfections, the edges should be inspected after treatment to ensure that the stringent requirements of the invention are met.

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The layers according to the invention can be formed by any conventional means, but the following plasma application methods are preferred: sputtering; plasma enhanced chemical vapor deposition; chemical vapor deposition, evaporative or ion beam plasmas. The most common of these is the splash process. The nature of these procedures is well known in the art and does not require further explanation in the context of this disclosure.

The strudel is formed directly on the bread surface. The nature / type of layers can vary within very wide limits. In our opinion, any film-forming material which is stable at high refractory temperatures (e.g., 900 ° C) and which adheres well to the glass surface under these conditions and under normal use can be used. Of the ten preferred film-forming materials, silicones are either nitrides, oxynitrides and fluorides of metal, or oxides of metal silicides, or mixtures of any two or more of these materials.

The particular choice of coating material will depend upon the cost and circumstances of the application technique to be used. We prefer the use of tin oxide and its application by spraying, but of course there are many other options, including oxides or other aluminum, nickel, chromium, titanium, and copper compounds, as well as alloys such as nickel-chromium alloys or stainless steel. steel application.

Preferably, the thickness of the layer is applied thereto _the to the minimum necessary to provide the required fire resistance. This is advantageous on the one hand, and on the other hand, the thinner the layer, the less transparency / interference on the glass. Generally, the film thickness is between about 10 Angstroms and microns, close to the lower limit, and the reduction in pure transparency due to the application of the film generally does not exceed 10 µm. For tin oxide, the preferred minimum thickness is about 10 angstroms. It is understood that the measurement of ultra-thin metal oxide layers is inherently inaccurate, so we want to give an order of magnitude of thickness rather than exact values. The optimum thickness Jlz can always be selected based on ε experience and experiment based on the circumstances.

We believe that the minimum thickness required to provide the required fire resistance is largely the same for every applicable layer.

In the process according to the invention, the layer can be applied to the glass either before or after the heat treatment operation. Thus, for example, the glass panes may first be sanded and heat treated, and subsequently provided with a layer, but it may also be accomplished by flattening the already coated glass and then heat treating the glass pane.

According to the invention, the layer can be applied to only one side of the glass pane, which will face the presumed fire in its installed position, by which measure fire resistance has already been ensured. However, it is usually desirable to apply one coat to each side of the glass pane, since in this final position of the glass pane, it does not limit the inhibition of fire propagation in only one direction, only in the other direction.

The fire-resistant glass panes of the present invention are intended to be used primarily in building structures to provide the required fire resistance properties. Thus the veneers are exterior large interior windows, glazed doors, etc. They may be large, built into internal walls, partitions, Spanish walls, etc. or other glazed building components. J5z glass panes are generally enclosed in refractory frames made of metal or wood having a suitable refractory coating, such as glaze or cover, such as a strip; thus, the unit as a whole provides the required fire resistance.

Λ In order to provide a better understanding of the invention, the following is a non-limiting example of the present invention,

<td>and the one attached</td><td>Referring to the drawings on which</td>

<td>1</td><td>an oven temperature curve is shown which is as a function of time, the glass panel test- changes in temperature during the course of the operation;</td>

<td>2</td><td>a cross-sectional view of an embodiment of a refractory glass pane according to the invention,</td>

<td>3</td><td>a refractory assembly according to the invention is shown in front view.</td>

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First example

Thus, the edges of a 6 mm thick glass pane of approximately 1 square meter were polished and polished to remove any peripheral imperfections. Subsequently, the glass plate was heat treated and tempered in a conventional heat treatment furnace to provide a fracture pattern / properties in accordance with BS Ö2O6A British Standard. The solidified and toughened glass sheet was then coated on both sides with a thin layer of tin oxide. Vacuum DC magnetron injection equipment was used for the application. First, one side of the glass sheet was applied with a layer, and secondly, through the other side, the layer was applied. The layer thickness was about 10 angstroms.

The glass panes provided with the layers as described above were able to withstand the heat effect up to at least 900 ° C, as required by British Standard BS476, without the layer being burnt. / British Standard 476 applies to tests on building materials and structures and parts 20 and 22 of this standard describe methods for determining the fire resistance of non-loadbearing components. Refer to this publication of the British Standards Institute for further details./ Figure 1 shows the evolution of furnace temperature / glass temperature practically the same during glass testing. The glass coating layer remains intact / intact.

Fig. 2 is a (non-scale) section showing a laminated glass sheet. With the 1 thin oxide layer, the 2 glass • 4 · «« ·· «• 4 · · ♦ ·· • 4 · · · ··· * ···

- Both sides of 13 sheets are covered with tan. The polished and polished edges of the bar face are designated by 3 reference numerals.

The rigid rectangular frame of refractory sheet steel 11 made of steel or wood is embodied in the rigid rectangular frame 10 of the embodiment according to the invention. It will be appreciated that the assembly of Figure 3 may comprise either a bar or a double glazing.

Second example

All of the procedure described in Example 1 was followed, but the polyrose step of the edges was omitted, so that only rough edges removed the edge edges, edges only completely. The resulting impact plate, which also had a layer, did not have a satisfactory fire resistance: it broke as the temperature on it increased.

Third example

All of the procedure described in Example 1 was followed by the fact that the layer (s) was chosen not as tin oxide but as oxides, nitrides, oxynitrides and fluorides of various metals and silicones. Testing of the resulting refractory glass panes gave results similar to those described in Example 1. A low-frequency magnetron was used to inject the silicone. The silicide layer also produced extremely satisfactory results.

4th example

A structural unit of 3 square meters in size, described in connection with JJ Figure 3, was prepared and tested for fire resistance. The unit remained intact even at temperatures above 9OO ° C, even after 30 minutes.