CZ227792A3 - Transparent refractory glass pane and process for producing thereof - Google Patents

Description

(57) The transparent fireproof glazing panel comprises at least one layer of swelling material associated with at least one structural layer of the panel. The swelling material layer is formed by combining the swellable hydrated metal salt and has a total water content of from 20 to 26%. In the panel manufacturing process, the swellable hydrated metal salt grains having a total water content of 22 to 26% by weight are separated into a layer on the surface of the layer to be incorporated into the panel, and while the grains are sandwiched between a pair of molding plates. conditions for degassing and consolidation and attachment to said surface of the panel layer. The panel layer and the molding plate may be identical and the second molding plate may also form the panel layer.

 , «Áíltiacur. ϋΙΜΠοδ VŠETEČKA attorney «tg 04 PRAHA 1, Žitná 25

A panel> hexaneether € process for producing Patel 'WHAT -v ¹ alpha

UM r ~ f

Technical field

The present invention relates to a transparent refractory glazing panel comprising at least one swelling material layer associated with at least one structural layer of a panel. The invention further relates to a method for producing a transparent refractory glazing panel as defined above.

BACKGROUND OF THE INVENTION

It is known to bond layers of swelling material to sheets of glazing material to form fire resistant panels. For example, such a layer of swelling material may be sandwiched between two glass sheets. Very important applications of such panels are transparent shades that allow illumination of the screened area, and closures of sight openings for rooms or other closures where there may be a risk of fire.

Typically, the performance of such panels is tested by incorporating them into a furnace wall, the internal temperature of which then increases according to a predetermined diagram. Details of such a test are given in International Standard ISO 834-1975. The fire resistance test method described in this standard is also given in ISO 9051-1990, which deals specifically with the fire resistance properties of glazed assemblies. It is appropriate to list here some parts of this standard.

Glass is a non-combustible material and therefore does not contribute to the spread of fire.

Glass exposed to heat may burst by thermal shock or soften and then not be held by the frame. Thus, only some types of glazing assemblies can be considered fireproof. The fire-resistance of glazed assemblies depends on the type of glazed product, the glazing method, the frame type, the panel size, the fastening method and the type of construction surrounding the glazed area.

Some transparent and translucent glazed assemblies may meet the requirements of stability and integrity (RE) and in some cases insulation (REI, where R stands for resistance, E for tightness) and I insulation.

Not only is the possibility of direct fire propagation through openings caused by glass fracture to take into account for fire prevention measures: it is also to take into account the number of heat-permeable glazing assemblies which can remain intact, and such heat can cause ignition of flammable, material materials.

-2 Glazing assemblies with fire resistance according to the RE class under the fire conditions defined in ISO 834 ensure stability and integrity at a given time. The temperature of the unexposed side is not taken into account.

Glazed assemblies with fire resistance according to the REI class under the fire conditions defined in ISO 834 ensure stability, integrity and insulation at a given time. ”

There are various grades of fireproof panel, and among these generally considered are grades that correspond to panels that constitute effective barriers to flame and smoke, i.e., RE class, for time periods of 15> 30, 45,60,90 and 120 minutes. Other stages correspond to panels that create effective barriers to the passage of flames and smoke and also have certain insulating properties, i.e., the REI class, again for periods of time, for example, 15, 30, 45, 60, 90 and 120 minutes.

The insulating properties that a panel must have to meet the REI standard are, in short, that no point of the surface exposed to the outside of the furnace must be exposed to a temperature greater than 180 ° C above its initial or ambient temperature, and the mean temperature of this surface shall not exceed 140 ° C. Such REI class panels may also create obstacles to the transmission of infrared radiation from the fire bearing.

It is of utmost importance that the swelling material layer of such a panel has good flame-retardant properties and also retains acceptable optical properties before it begins to swell when the flame is running.

For many years, hydrated metal salts, such as metal silicates, especially alkali metal silicates, have been used in the manufacture of such panels. Typically, the layers incorporated in the finished panels had a water content of 29% to 35% · When describing the water content in this description, it is the weight fraction of water relative to the swelling material used to form the layer or the weight fraction relative to the swelling material embedded as a layer in the finished panel before the fire breaks out and then reshapes the layer. During the fire, the water of hydration is expelled by the heat of the fire, and the layer of swelling material is transformed into an opaque foam which acts as a barrier to radiated and conduction heat and can also serve to bond structural panel layers such as glass layers.

-3They may be disturbed by thermal shock caused by fire. (The panel's performance as an obstacle to flame and smoke penetration is thus prolonged.

the lability of the hitherto known type of panel as a fire shield depends on several factors, the lability of a laminate consisting of a single layer of a given swelling material sandwiched between two glass sheets of a given thickness increases with the thickness of the swelling material. For a previously known panel of a given basis weight, i.e. for the same overall thickness of the glass and the swelling material, the efficiency of such a known panel can be increased by forming as a five-layer laminate comprising two layers of swelling material sandwiched between three glass sheets. Laminate of three 4 mm glass panes. bonding two layers of swelling material of 1 mm thickness proved to be much more effective than a laminate of two 6 mm glass sheets enclosing one layer of swelling material of 2 mm thickness. Thus, the same efficiency can be achieved by using a thinner panel having multiple layers. It is clearly desirable to provide segments effective fire resistant panels having a low basis weight, but the manufacture of panels with four or more layers can be very costly.

Another problem associated with the use of hydrated metal salt layers as layers of swelling material is the aging of the material with time. This aging is manifested as a violation of the optical properties of the panel, for example, a decrease in the transparency of the hybride swelling material, which reduces the transparency of the panel.

For many years was he known? the problem of deterioration of the optical properties by aging of a fireproof panel comprising a layer of swelling material. Various efforts have been made to address this problem. The most significant cause of the optical properties was the formation of: microbubbles in or on the layer and it is known to form the layer by in situ drying of an aqueous solution of a hydrated metal salt that has been degassed, taking care not to stir the solution too vigorously to avoid to re-dissolve air or other gas that could occur when the dried layer ages. Although this measure improves the aging properties of the panel, it is not entirely satisfactory if the panel is to be used under conditions where it is exposed to moderate heat, such as

-4 sunlight. It is also known to add some stabilizing agent to a hydrated metal salt, such as a partially dissociated organic nitrogen compound, for example a quaternary ammonium compound such as tetramethylammonium hydroxide, which gives better results.

An object of the present invention is to provide a transparent fire-resistant glazing panel which has good aging properties which are not substantially dependent on the use of such an additive, and which also has good fire-resistance properties during the fire.

SUMMARY OF THE INVENTION

The invention solves the object by making transparent fireproof

A glazing panel comprising at least one layer of swelling material associated with at least one structural layer of a panel, comprising a structural layer which is joined to a layer of swelling material which has been formed by joining a swellable hydrated metal salt with a total water content from 20 to 2.6% by weight.

It has been found that such a panel is less susceptible to losing its optical properties over time than a known panel in which the water content is somewhat higher. Indeed, the aging properties of the panel according to the present invention are, at the same other parameters, better than those of a panel whose swelling material has a higher water content in the range of 29% to 34% by weight and which contains a stabilizing agent such as tetramethylammonium hydroxide.

This is rather surprising and it is not entirely clear why this favorable result is achieved by using a swelling layer having a lower water content.

Further, it is surprising that such a panel may have improved fire resistance properties, as it would rather be expected that a lower water content in the swelling layer would reduce the panel efficiency, as the foaming action during fire would be reduced. In fact, it has been found that a three-layer laminate comprising one layer of swelling material sandwiched between two glass sheets according to the present invention has a better fire resistance than a three-layer laminate of similar dimensions whose swelling layer has a higher water content. The invention therefore has the additional advantage of allowing the same degree of fire resistance to be achieved at; using a thinner and lighter panel without the added complications and cost of increasing the number of laminate layers.

The lower water content in the swelling layer, maximum 26%, is effective

-5the increase in its hardness, so it is physically more stable and has less tendency to split. It is preferred to produce a layer with a water content of not less than 20% for the manufacture of panels having good transparency.

Preferably, the layer has a water content of not less than 22%.

The presence of such proportions of water in the swelling layer very well in

promotes foaming properties during fire and also allows the formation of a hard and compact layer of swelling material that maintains good optical properties over time. Optimally, the layer has a total water content of not less than 23%.

For best results, it is preferred that the layer have a total water content of not more than 25%, as this promotes maintaining good optical properties independent of panel aging.

Such a grain layer can be easily consolidated by subjecting it to suitable thermal and pressure conditions to form a layer in which the individual grains are not visible to the naked eye, so that the layer has a uniform appearance and is transparent. However, the presence of such grains may be revealed, for example, by ultrasound testing or microscope observation, and the grain boundaries, although invisible, are believed to remain in the layer. It is contemplated that this layer structure may have some effect on the behavior of the swelling material during the fire and also on the properties of the layer before the fire. One possible contributing factor for improving the fire resistance of the panel of the present invention is that although grain boundaries disappear to the naked eye, they can remain and act as a plurality of bubble-forming sites in the reaction of the swelling material during fire resulting in a fine foaming structure. good and uniform insulation effect over the entire panel area.

The grains preferably have a maximum dimension less than 100 µm and are preferably greater than 10 µm and, for example, have a maximum dimension between 150 µm and 500 µm. This helps to easily form the grains into a compact layer and may also have a beneficial effect on the behavior of the swelling material during fire. It has been found that panels having this measure according to the invention give a fine and uniform structure of the foam when subjected to the intense heat generated by the fire. It is believed that this is mainly due to the relatively low water content of the swelling material as compared to the water content still used in the manufacture of the fire-resistant panels, as well as to the fact that some residual grain remains in the reinforced layer. The layer may also be a favorable factor.

As noted, the efficiency of the fireproof panel during fire depends at least in part on the thickness of the layer or each layer of the swelling material. Preferably, the swelling material layer has a thickness of from 0.1 to 5.0 mm. Layers with a thickness of 0.1 mm can provide adequate short-term fire protection, although naturally better protection is due to thicker layers. In general, increasing the thickness of such a layer above 5 mm does not give a reasonable increase in protection, and it has also been found that it is more difficult to form thicker compact layers having good optical properties.

The swelling material may be selected from a large number of hydrated metal salts, although an alkali metal salt is preferred. Examples of suitable alkali metal salts which may be used in hydrated form are: potassium aluminate, potassium lead, potassium tinate, sodium tinate, sodium aluminum sulfate, potassium aluminum sulfate, sodium borate, potassium borate, sodium orthophosphates and potassium silicate. For reasons of cost and efficiency, however, it is preferred that said swellable material is hydrated sodium silicate, which may optionally be mixed with hydrated potassium silicate.

The panel preferably comprises two structural layers which are laminated with a layer of swelling material. This is a very stable and simple panel structure. In the simplest form, such a laminate may consist of two sheets of glazing material which are directly bonded to each side of the swelling material layer. Alternatively, if a higher degree of fire protection is desired, two layers of swelling material may be joined to form a laminated panel with three structural layers of the glazing material. It will be appreciated that when greater fire protection is desired, two or more such panels may be laminated, for example by using an embedded adhesive material such as polyvinyl butyrate in a manner known in the art of glazing laminates.

It has already been said that the aging properties of the panel according to the present invention are better than those of a panel whose swelling material layer has a higher water content in the range of 29% to 34% and contains a stabilizing agent at the same other parameters. that there is no reason to use such a stabilizing agent in a panel whose swelling material layer has a low water content according to the present invention since such a panel already has very good

-Ί aging properties. However, the use of such stabilizing agents may cause a further improvement in the aging properties of the panel of the present invention and may have some and very unexpected advantage that the use of such an agent promotes the fire-resistance properties of the layer during fire and this is particularly beneficial in a panel having multiple layers of swelling material containing such an additive. . It is therefore preferred that such layer-intumescent material comprises at least one stabilizing ^agent: silicates

Stabilizing agent; The silicate preferably comprises at least one organic nitrogen compound, for example an amine compound that is at least partially dissociated, for example quaternary (an ammonium compound such as tetramethylammonium hydroxide. It is contemplated that adding a stabilizing agent such as tetramethylammonium hydroxide according to a preferred embodiment of the present invention o aging of the panel, but can also have a beneficial effect on the foam produced during the fire and thus contribute to the fire resistance of the panel.

The panel according to the present invention can be manufactured very simply. SUMMARY OF THE INVENTION The present invention provides a process for the manufacture of a transparent fire-resistant glazing panel comprising at least one layer of swelling material associated with at least one structural layer of a panel, which comprises separating grains of a swellable hydrated metal salt having a water content of 22% to 26% the layer to be incorporated into the panel and while the grains are sandwiched between the pair of molding plates, the layer is subjected to thermal and pressure conditions for degassing and solidification and bonding to said surface of the panel layer.

Such a method is very simple to carry out and can be carried out using devices known in the art of glazing laminates.

In addition to providing very good aging properties and fire resistance of the panel, the choice of swelling grains having said water content gives other advantages. The use of swelling grains having a water content of not more than 26% promotes the retention of the optical properties of the panel irrespective of its aging and such grains are also suitable for handling before and during the manufacture of the panel. The swellable grains having a water content of not less than 22% are readily solidified into hard and transparent layers, or at least into layers that become transparent when interconnected between two transparent sheets. This does not mean that the resulting swelling layer will necessarily have a water content of 22% or more. Some water is likely to be removed during degassing, but the mean water content of the layer will be only slightly lower than the mean water content of the grains ^; from which the layer was created. It has been found that the difference in water contents in the grains and in the layer is at most 2% and can be neglected, so that for example a layer made of grains with an average water content of 25% will have a mean water content between 23% and 25%. When grains with a lower water content are used for the production of the layer, it is desirable to control the degassing conditions so that only a small amount of water is removed: it is not desirable that the mean water content of the layer be less than 20%. less than 22%.

During degassing and consolidation, the swelling layer is attached to the layer in the panel with which it is in contact. This layer may be a film of thermoplastic adhesive material for subsequent bonding to a structural layer of a panel such as glass sheets, and although this is particularly desirable for a particular reason, it introduces a particular step in the manufacturing process and therefore grain distribution into the layer is preferred. a surface of the glass sheet which will form part of the panel and which also forms the forming plate.

If it is desired that the second shaping plate is not bonded to the resulting swelling material layer, the latter may be suitably treated, for example with silicone, but it is preferred that the second shaping plate is formed by or adjacent to the layer to be incorporated. into the panel and to which the swelling material layer will be attached. Thus, a layer of swelling material may be sandwiched between two layers of a panel that is laminated together with degassing and consolidation. The panel can then be delivered to the autoclave for the next high pressure bonding step, if desired.

Note that any desired number of successively alternating layers of glazing material and swelling material may be laminated in such a manner, but the difficulty of producing a laminate having good optical properties increases with the number of layers of swelling material, particularly when three or more such layers are to be consolidated and the grouping is to be subjected to heating during consolidation and / or bonding of such layers as described below.

It will also be noted that two or more such panels consisting of alternating layers of glazing material and swelling material can be laminated using a film of adhesive thermoplastic material when greater fire resistance is desired.

Such a process has practical advantages in cases where it is desirable to incorporate multiple layers of swelling material.

As a practical example, it could be desirable to produce a fireproof panel having four layers of swelling material, each 1.5 mm thick. It has been found that the layers of grains of the swelling material to form such reinforced layers must be up to seven times thicker than the reinforced layers, so that such a panel can shrink by up to 36 mm in thickness during degassing and bonding. Production is simplified by forming two panels each having two layers of swelling material and laminating these panels using a film of a sticky thermoplastic material such as polyvinyl butyral. Presence. Such a film of sticky thermoplastic material can also have a beneficial effect on the fire resistance properties of the panel by limiting the thermal shock fracture transmission.

In the most preferred embodiments of the invention said grains have a total water content of not less than 23% and preferably not more than 25% by weight. The presence of such proportions of water in the swelling grains results in good foaming properties of the resulting layer during fire and also allows the formation of a hard and compact layer of swelling material that has and retains good optical properties over time *

Preferably, the grains have a size such that at least 90% by weight of the grains have a maximum dimension of less than 700 µm, preferably in the range of 150 µm to 500 µm. Grains of such sizes are convenient to handle and give the resultant reinforced layer a structure which is believed to be beneficial to the good fire-resistance properties as mentioned above. Such grain sizes are also particularly advantageous for forming layers of the most desired thicknesses, for example from 0.1 to 5.0 mm.

Preferably, at least part of the degassing and bonding time, the layer of swelling material is subjected to a temperature of at least 80 ° C. Heating the swelling material to such a temperature helps to degass and consolidate, as well as bonding to the panel layer. It should be noted that the swelling material must not be subjected to such high temperatures that, due to the pressure exerted on the swelling material,

-10 cause premature foaming of the swelling material * It is noted that it is much easier to ensure that a single layer of swelling material, or each of the two layers of swelling material of a panel, is subjected to an optimal heating process than to ensure that each of three or more layers is optimally heated, although only because the middle layer or layers are more shielded from the heat source by other panel layers than the outer layers.

Preferably, during degassing and bonding, the swelling material layer is subjected to a pressure of less than 30 kPa. This allows perfect degassing of the swelling material.

In the foregoing, the use of additives in the swelling material layer has been discussed to improve its aging properties. The use of such an additive may have other unexpected advantages in improving fire resistance during fire, as has also been reported. It is therefore preferred that the swelling material comprises at least one silicate stabilizing agent, and preferably a stabilizing agent comprising at least one organic nitrogen compound, for example an amino compound that is at least partially dissociated, for example a quaternary ammonium compound such as tetramethylammonium hydroxide.

Overview of Figures> in the drawings

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram of an apparatus for degassing and consolidating a layer of swelling material according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a panel formed from two glass panes 1,2 and an intermediate layer 2 ^{of grains of} swelling material having a total water content of between 22% and 26%. The grains have a size ranging from 150 µm to 500 µm. The grains are simply dispersed on the first glass sheet in a layer seven times thicker than the resulting thickness of the reinforced layer to be produced. The panel is enclosed in the housing 8. The housing 6 is connected by suction line 6 to the pump 6, which can maintain the vacuum in the housing 6 and also in the gap between the glass panes 1 and 2. When the pump 6 operates, the upper and lower walls of the housing 6 are attracted to the outer surfaces of the assembly enclosed in the housing 6. and the glass sheets 1,2 act as forming plates for strengthening the layer 2 of the swelling material. The housing 6 is at least near its peripheral region 2

Sufficiently rigid to resist clamping against the edges of the stack of layers 1, 2, 2 such that a vacuum is maintained in the cavity (8) by the pump (6) around its edges in the housing (4).

The use of a sleeve 8 that surrounds the stack of layers 1, 2, 2 has the advantage that the size of the sleeve 5 with respect to the dimensions of the stack of layers 1, 2, 2, 2, 2, 2, 2, 2, 2. ^nen 4 critical. The housing 4 can be used for stack assemblies 1, 2, 2. different sizes. The use of such a sleeve 4 also facilitates the application of the same pressure over the entire surface of the main surfaces of the stack of layers 1, 2, 2 during their processing so that reaction forces arising from pressure differences between the environment in which the sleeve is located and caused bending of the 1,2 sheets. Such a bend could lead to the formation of bubbles in the edges of the swelling material layer 2 and could also cause unevenness. final product.

In a variant of the apparatus described, optional support means are provided to accommodate the reaction forces generated by pressure differences between the inside and outside of the housing. In Fig. 1 such support means are shown as a pair of frames 2 of the same shape but larger in size than the stack of layers 1, 2, ^and held by the spaced posts 10 to keep the sleeve 6 away from the edges of the stack of 1, 2, 2 layers. 2 is shown in the drawing.

Heaters (not shown) may be provided for the upper and lower surfaces of the housing 6 to heat the swellable material layer 2 sandwiched between the glass sheets 1.2 to facilitate consolidation and bonding of the layer assembly 1,2,2 *.

The layer assembly 1, 2, 2 shown in FIG. 1 can be treated by a pumping device in a simple process in which the outside of the housing is always exposed to air pressure. In one example of the method, the pump 6 is started to reduce the pressure in the housing, i.e. the pressure exerted on the edges of the stack of layers 1.2 to the peripheral cavity 8, to a value below 30 kPa. The exact optimum value will depend on the water content of the swelling grains used. The setpoint can be reached after a few minutes and is maintained after. another 100 minutes. The stack of layers 1, 2 ^{, 2} initially has a room temperature of about 20 ° C, and then heats inside the enclosure 6 until it reaches a temperature of 90 ° C after 45 minutes.

After the desired degassing, the pressure within the housing is brought back to atmospheric pressure for about 15 minutes. At the end of this time, it is found that the swelling material layer 2 is strengthened so that the grain boundary boundaries are not visible to the naked eye and the layer assembly 1, 2, 2 is joined into a transparent laminate panel. Optionally, the panel may be transferred to an autoclave for high pressure treatment, if desired.

It has been found that the water loss in the swelling material due to the suction during consolidation into the layer is less than 2% by weight of the layer.

Example 1

The above-described series of panels was prepared using glass sheets of 3 mm thick intumescent interlayer having a thickness of 1.5 mm and a total water content of from 23.5% to ^24: 5r% of intumescent layers each such panel was formed They have a grain size having a total water content of 24.5% and sieved so that their dimension is from 150 µm to 500 µm. The weight ratio of silica to sodium oxide in sodium silicate was between 3.3: 1 and 3.4: 1. The grains of the swelling material contained no tetramethylammonium hydroxide as a flame retardant.

A series of comparative test panels of similar dimensions were produced in a conventional manner, in which to form such a panel, the hydrated sodium silicate solution was dried in situ on a 3 mm thick glass sheet to form a 1.8 mm thick layer over a thickness range of 1.5 mm up to 2,1 mm and with a total water content of 29% to 34%. The solution contained. 0.25% by weight of tetramethylammonium hydroxide as an anti-aging additive. Again, the weight ratio of silica to sodium oxide in sodium silicate was between 3.3: 1 and 3.4: 1. A second 3 mm glass sheet was attached to this layer to form a laminated panel.

The panels were framed in substantially the same frames to create glazing assemblies for testing in accordance with ISO 834-1975.

The two glazing assemblies, each of one row of panels, were then built side by side into the furnace wall and the furnace was heated according to a desired predetermined pattern to test the stability and integrity of both assemblies as barriers to flame and smoke penetration according to the RE class. The comparative test kit was found to satisfy ISO 834 at the RE level for 30 minutes but not for 45 minutes. The assembly comprising the panel of the present invention satisfied the ISO 834 standard at an RE level above 60 min.

13Both types of panels were also subjected to aging tests. In the first test, the panels were held at 80 ° C for 15 days. At the end of this time, no microbubbles were visible in the panel according to the present invention, while in the comparative test panel a number of bubbles were visible so as to create fogging regardless of the presence. a stabilizing agent in its swelling material layer. In the panel of the present invention, fogging only occurred after 30 days. In the second test, the panels were exposed to ultraviolet radiation for 500 hours. The panel according to the present invention contained no microbubbles after this time, but the comparative test panel contained more than twice the amount of bubbles than after the first test.

Example 2

Two further rows of panels according to the invention were produced using the same starting materials as in Example 1. In these rows, the panels consisted of three 3 m glass sheets and two layers of intumescent material 1.5 mm thick. In one of the panels of the invention, the swelling material layers contained a proportion of tetramethyl ammonium hydroxide; second, there was no such additive. Tetramethylammonium hydroxide was added by addition to the silicate solution from which the grains were formed in a proportion of 0.125% by weight. Many comparative test panels of the same structure were made using a hydrated solution. sodium silicate with tetramethylammonium hydroxide addition as specified for the comparative test panels in Example 1. The swelling layers of such comparative test panels had an average thickness of 1.8 mm.

The panels were again framed into identical frames to create glazing assemblies for testing in accordance with the international standard ISO 834-1975.

Such glazing assemblies were then built side by side into the furnace wall and the furnace was heated according to the desired predetermined scheme for testing the stability, integrity and insulation of both KEI class rows. Various assemblies have been found to have the ability to maintain integrity as a barrier to flame penetration and smoke as well as meet insulation requirements in the KEI class for between 30 and 35 minutes.

Other members of each row of glazing assemblies were subjected to the aging tests given in Example 1. It was found that according to each test all panels of the invention gave better results than comparative test panels and also those panels of the invention in which the swelling material contained tetramethylammonium hydroxide. , gave better results than panels without it.

Example 3

Two further rows of panels according to the invention were made as described in Example 2 except that one of the outer glass panes of the panel had a thickness of 2 mm instead of 3 mm. The panels of each row were laminated with a 2 mm glass sheet inside using 0.76 nm thick polyvinyl butyral films.

In one row of these polyvinyl butyral laminated panels each contained four layers of 1.5 nm thickness of hydrated sodium silicate with tetramethyl ammonium hydroxide, while in the second row it was not used.

The panels were again framed in substantially identical frames to create glazing assemblies for testing in accordance with ISO 834-1975 ·

The assemblies were then built side by side into the furnace wall and the furnace was heated according to the desired predetermined scheme to test the effectiveness of both panel rows, again according to the EEI class. It was found that those assemblies whose panels did not contain tetramethylammonium hydroxide were able to maintain integrity as a barrier to flame and smoke penetration and satisfy EEI class insulation requirements for 55-70 minutes. The assemblies of the invention, the panels of which contained tetramethylammonium hydroxide, remained effective as barriers to flame and smoke penetration and satisfy the EEI class insulation requirements for 70 to 80 minutes.

Example 4

Another series of glazing assemblies was made by laminating and framing the three panels of the invention made by the method of Example 2 using 0.76 mm thick polyvinyl butyral layers. The assemblies were then built side by side into the furnace wall and the furnace was heated according to the desired predetermined performance test scheme of the assemblies, again according to the EEI class. The kits of the invention have been found to remain effective as barriers to flame and smoke penetration and meet the REI class insulation requirements for more than 90 minutes, and when tetramethylammonium hydroxide was used as an flame retardant additive to meet the REI class requirements for 110 minutes .

Example 5

Two fire-resistant panels according to the invention were produced _, each containing three glass sheets of 3 mm thickness and two layers of swelling material of 0.6 mm thickness. In one panel, the swelling material contained tetramethylammonium hydroxide as a flame retardant according to Example 2, in the other panel such additive was not used.

Framed assemblies containing the two panels were then tested for stability, integrity and insulation according to the REI class when exposed to fire. The panel without additive was eroded after 34 minutes.

The additive panel withstood the effects of the test for 35 to 36 minutes.

Example 6

Two fireproof panels were made, each containing three 3mm, 8mm and 3mm glass sheets and two layers of swelling material. In one panel, each layer of swelling material was formed according to the invention according to the method of Example 1 with a thickness of 2.5 mm. In the second panel, the swelling material layer was formed with a thickness of 1.8 mnt using the classical technique described in connection with the comparative test panel of Example X.

Framed assemblies containing the two panels were then tested for stability, integrity and insulation according to the SEI class when exposed to fire. The comparison test panel was disrupted after 40 minutes. The panel according to the invention withstood the effects of the test for 50 minutes.

Claims (22)

PATENTOVÍ A transparent refractory glazing panel comprising: ^{- a} < 1 ^& gt ^; pun one layer of swelling material associated with at least one structural layer of a panel, comprising a structural layer which is bonded to a layer of swelling material which has been formed by joining grains of swellable hydrated metal salt; water content from 20 to 26%. 2. A transparent fire-resistant glazing panel according to claim 1, characterized in that it comprises two structural layers which are laminated together with said layer of swelling material. 3. A transparent fire-resistant glazing panel according to claim 1 or 2, characterized in that the swelling material layer has a total water content of not less than 22%. 4. The transparent fire-resistant glazing panel of claim 3, wherein the swelling material layer has a total water content of not less than 23%. A transparent fire-resistant glazing panel according to any one of claims 1 to 4, characterized in that the swelling material layer has a total water content of not more than 25%. 6. The transparent fire-resistant glazing panel according to any one of claims 1 to 5, characterized in that the grains have a maximum size of less than 700 [mu] m, and preferably have a size of from 150 [mu] m to 500 [mu] m. 7 /. Transparent fire-resistant glazing panel according to any one of claims 1 to 6, characterized in that the swelling material layer has a thickness of 0.1 mm to 5.0 mm. 8. A transparent fire-resistant glazing panel according to any one of claims 1 to 7, wherein the swellable material is hydrated sodium silicate. 9. The transparent fire-resistant glazing panel according to any one of claims 1 to 8, wherein the layer of swelling material comprises at least one silicate stabilizing agent. 10. The transparent refractory glazing panel of claim 9, wherein the silicate stabilizing agent comprises at least one organic nitrogen compound, for example an amino compound that is at least partially dissociated, for example, a quaternary ammonium compound such as tetramethylammonium hydroxide. A method of making a transparent fireproof glazing panel comprising at least one layer of swelling material bonded -17 with at least one structural layer of the panel, characterized in that the grains of the swellable hydrated metal salt having a water content of 22% to 26% by weight are divided into a layer on the surface of the layer to be built into the panel; of the molding plates, the layer is subjected to thermal and pressure conditions for degassing and consolidation and bonding to said panel layer surface. 12. The method of claim 11, wherein the grain layer is distributed on the surface of the glass sheet to be incorporated into the panel and forming said forming plate. Method according to claim 12, characterized in that the second molding plate comprises a layer to be built into the panel and to which a layer of swelling material is attached. 14. A method according to any one of claims 11 to 13, wherein the grains have a total water content of not less than 23% by weight. 15o A method according to any one of claims 11 to 14, wherein the grains have a total water content of no more than 25% by weight. 16. A method according to any one of claims 11 to 15, wherein at least 90% by weight of the grains have a maximum dimension of less than 700 .mu.m and preferably has a size of from 150 .mu.m to 150 .mu.m. 500 µm. 17. A method according to any one of claims 11 to 16 wherein the layer of swelling material is formed in a thickness of from 0.1 mm to 5.0 mm. 18. The method of any one of claims 11 to 17, wherein the layer of swelling material comprises hydrated sodium silicate. A method according to any one of claims 11 to 18, characterized in that at least part of the degassing and bonding time the layer of swelling material is subjected to a temperature of at least 80 ° C. 20. A method according to any one of claims 11 to 19, characterized in that during degassing and bonding the layer of swelling material is subjected to a pressure of less than 30 kPa. 21. The method of any one of items 1 to 20, wherein the swelling material comprises at least one silicate stabilizing agent. 22. The method of claim 21, wherein the silicate stabilizing agent is at least one organic nitrogen compound, e.g.