Fireproof glazing

Abstract

The fire resistant glazing comprises at least three transparent plies and at least two transparent fire resistant layers, each fire resistant layer being intermediate of two plies, and each outer ply has a bending stiffness 1.5 to 15 times greater than the bending stiffness of at least one inner ply. In one embodiment, each outer ply has a thickness 0.20 mm to 16.00 mm greater than the thickness of at least one inner ply.

Description

[Technical field]

[0001] The present invention relates to a fire resistant glazing having improved fire resistance compared to conventional fire resistant glazing. [Background technology]

[0002] The fire resistant glazing may comprise a laminate of at least two transparent plies and at least one transparent fire resistant layer, each fire resistant layer being disposed as an intermediate layer between two plies.

[0003] Typically, each of the transparent plies of the laminate comprises a transparent sheet of an organic material such as a pane of float glass or polycarbonate, and each of the transparent fire-resistant layers comprises an inorganic intumescent material that expands or foams (expands) when the glazing is exposed to fire to form a barrier layer that is resistant to the passage of hot gases and flames, as well as to heat conduction and radiation.

[0004] Expansion is often accompanied by a cooling effect and the release of water vapor from the intumescent material, both of which serve to reduce heat transfer through the glazing.

[0005] These fire resistant glazings are sometimes provided with safety glazing to give the fire resistant glazing high impact resistance. Typically the safety glazing is a laminate comprising two panes of glass and a transparent plastic film that bonds the panes together.

[0006] Currently, these fire resistant glazings are used in a variety of fire glazing systems and in a variety of locations.

[0007] The fire-resistant glazings sold under the trade names Pyrostop® and Pyrodur® can be installed in a huge number of door and wall partitions, in sloping or horizontal roofs or floors. They can also be used as building facades.

[0008] Fire-resistant glazing employing toughened glass panes, such as those known as Pyrostop® T and Pyrodur® T, are widely used in ship bulkheads or hulls. They may also be used inside the hull.

[0009] Fire glazing systems, including these fire resistant glazings, must meet the fire resistance classification of the relevant building, railway and / or maritime authorities, whilst there is a constant need to improve protection against fire. Summary of the Invention [Problem to be solved by the invention]

[0010] The present invention generally aims to address this need by providing a fire resistant glazing that has improved fire resistance performance compared to conventional fire resistant glazing. [Means for solving the problem]

[0011] Thus, in a first aspect, the invention provides a fire-resistant glazing comprising a laminate of at least three transparent plies and at least two transparent fire-resistant layers, each fire-resistant layer being an intermediate layer of two plies, and each outer ply having a bending stiffness that is 1.5 to 15 times greater than the bending stiffness of at least one inner ply.

[0012] References herein to the bending stiffness of a ply are to the bending stiffness of a single ply, i.e. a ply that does not form part of the glazing.

[0013] The bending stiffness K may be calculated from the equation K=EI, where E is the modulus of elasticity of the ply's material and I is the moment of inertia of the ply about a central axis parallel to its width dimension.

[0014] It should be noted that the second moment of area I of a ply is the second moment of area given by the sum of the squares of the perpendicular distances of the element area from the centroid axis.

[0015] For plies with edge (thickness) profiles of regular geometric shapes, the second area moment can be determined from standard formulas found in reference texts on architecture, engineering and manufacturing technology (such as Lexikon der gesamten Technik).

[0016] For a ply with a rectangular edge profile, the second moment of area I about the ply's centroid axis parallel to its width dimension y is the formula bh 3 / 12, b is the width of the ply and h is the thickness of the ply.

[0017] In some embodiments, the bending stiffness of each outer ply is between 3 and 10 times greater than the bending stiffness of at least one inner ply, such as 5 or 8 times greater.

[0018] In other embodiments, the bending stiffness of each outer ply is between 3 and 10 times greater than the bending stiffness of each inner ply, such as 5 or 8 times greater.

[0019] It will be appreciated that the relative bending stiffness of the plies may be obtained by appropriate selection of one or more of the ply's elastic modulus, edge profile shape, and thickness.

[0020] It should be noted that the elastic modulus of glass can vary over a very wide range of values ​​(i.e., several orders of magnitude) and often depends on how the glass is made. Reinforced glass can have an elastic modulus that is significantly different from that of unreinforced glass.

[0021] In one option, the plies have the same edge profile and thickness, but each outer ply has a modulus of elasticity suitably greater than the modulus of elasticity of at least one or each inner ply.

[0022] Each outer ply may comprise the same glass, or one ply may comprise a different glass than the other outer plies. Further, each inner ply may comprise the same glass that is different from each outer ply, or one or more inner plies may comprise a different glass than each outer ply and any other inner ply.

[0023] In some embodiments, each outer ply comprises a sheet of tempered float glass and each inner ply comprises a sheet of non-tempered float glass.

[0024] In other embodiments, each outer ply comprises a sheet of float glass and each inner ply comprises a sheet of polycarbonate, the float glass of each outer ply having a modulus of elasticity suitably different from the modulus of elasticity of at least one or each of the inner plies.

[0025] In another option, each ply has the same thickness and the same modulus of elasticity, but the edge profile of each outer ply suitably differs from the edge profile of at least one or each inner ply.

[0026] The edge profile can be a straight line, a triangle, a circle, a semicircle, a regular trapezoid, a hexagon, a ring, an ellipse, a rectangular box cross section, an angular, a Plus, an I-shape, a T-shape, or a U-shape profile.

[0027] It should be noted that at least one surface along the length of the ply is preferably flat, although curved, angled, or concave surfaces are also possible.

[0028] In yet another option, the fire resistant glazing comprises plies of the same material and edge profile, the thickness of each outer ply suitably differing from the thickness of at least one or each inner ply.

[0029] This choice is not only convenient given the wide availability of float glass sheets, but is also desirable because the bending stiffness of such sheets (with a straight edge profile) increases greatly (cubically) with even a small increase in the thickness of the sheet.

[0030] In yet another option, the fire resistant glazing may comprise plies having different edge profiles, thicknesses, and different materials, provided that the bending stiffness of each outer ply is suitably greater than the bending stiffness of at least one inner glass sheet.

[0031] In any option, each outer ply may have a thickness between 0.20 mm and 10.00 mm greater than the thickness of at least one of the inner plies or each ply.

[0032] It should be noted that the invention therefore also provides a fire-resistant glazing comprising a laminate of at least three transparent plies and at least two transparent fire-resistant layers, each fire-resistant layer being an intermediate layer of two plies, and each outer ply having a thickness between 0.20 mm and 16.00 mm greater than the thickness of at least one inner ply.

[0033] The fire-resistant glazing may in particular have n plies and n-1 plies of fire-resistant layers, where n is an integer between 3 and 15, for example 4, 7, 11 or 13.

[0034] In some embodiments, the fire resistant glazing has 4 plies and 3 fire resistant layers, 5 plies and 4 fire resistant layers, 6 plies and 5 fire resistant layers, 7 plies and 6 fire resistant layers, 8 plies and 7 fire resistant layers, or 9 plies and 8 fire resistant layers.

[0035] The thickness of each outer ply may be between 0.50 mm and 5.00 mm greater than the thickness of at least one inner ply, for example, 1.00 mm, 1.50 mm, or 3.00 mm.

[0036] Additionally, the thickness of each outer ply may be between 0.50 mm and 5.00 mm greater than the thickness of each inner ply, for example 1.00 mm, 1.50 mm, or 3.00 mm.

[0037] In some embodiments, each outer ply has a thickness greater than 3.00 mm, for example 4.00 mm. In these embodiments, each inner ply may have a thickness between 1.50 mm and 3.00 mm, for example between 2.50 mm and 3.00 mm.

[0038] It should be noted that it is not necessary for each ply to be of uniform thickness, only that its average thickness correspond to a predetermined value.

[0039] In a preferred embodiment, the fire-resistant glazing has a total thickness of less than 65 mm.

[0040] In some embodiments, each of the outer plies has the same thickness, and each of the inner plies has the same thickness, or one or more of the inner plies has a thickness that is less than the thickness of another of the inner plies.

[0041] In other embodiments, one outer ply has a thickness greater than the thickness of the other outer ply, and each inner ply has the same thickness, or one or more inner plies have a thickness less than the thickness of another inner ply.

[0042] In a preferred embodiment, each ply comprises float glass sheets of the same modulus of elasticity and straight edge profile. Each outer glass sheet has a thickness greater than the thickness of at least one or each inner glass sheet.

[0043] Inorganic glasses suitable for the practice of the present invention include alkali silicate glasses, alkali borosilicate glasses and alkali aluminosilicate glasses, as well as ceramic glasses such as those sold under the trade name Firelite® by Nippon Electric Glass Co., Ltd.

[0044] Suitable organic glasses include polycarbonate and poly(methyl methacrylate), sold under a number of trade names including Perspex®.

[0045] The or each outer ply may have an anti-reflective or self-cleaning coating on its outer surface, and the or each inner ply may have a low-emissivity coating on its outer-facing surface and / or its inner-facing surface.

[0046] It should be noted that float glass sheets with anti-reflective coatings are sold under the trade name Optiview™, float glass sheets with self-cleaning coatings are sold under the trade names Activ® and SaniTise™, and float glass sheets with low-emissivity coatings are sold under the trade name K Glass™.

[0047] The fire resistant layer may comprise any fire resistant material used in the art. Preferably, the fire resistant material comprises at least 20% water by weight.

[0048] The fire-resistant material may comprise a hydrogel based on aluminum hydroxide or polyacrylate. Preferably, however, the material comprises an intumescent material such as water glass. The water glass may in particular be sodium water glass, potassium water glass or lithium water glass.

[0049] Suitable sodium water glass includes sodium silicate (SiO2:Na2O) water glass having a weight ratio of SiO2:Na2O of at least 1.6:1.0, preferably from 2.0:1.0 to 6.0:1.0, for example 4.0:1.0.

[0050] Other suitable sodium water glasses include those based on sodium silicate (SiO2:Na2O) in which the sodium ions are partially replaced by potassium and / or lithium ions.

[0051] The molar ratio of sodium ions to potassium and / or lithium ions in these water glasses may be at least 2:1, in particular in the range of 1.4:1.0 to 2.5:1.0.

[0052] In one embodiment, where the waterglass comprises a mixture of sodium and potassium silicates, the molar ratio of sodium ions to potassium ions is at least 4.0:1.0.

[0053] A fire-resistant layer comprising sodium waterglass may be provided on the plies by controlled evaporation ("pouring and drying") of an aqueous solution comprising an alkali metal silicate and, optionally, a polyol such as glycerol or diethylene glycol, an acrylate, a polysaccharide such as cellulose or starch, or a collagen such as gelatin, which acts as a coolant during evaporation.

[0054] Suitable potassium water glasses include potassium silicate (SiO2:K2O) water glasses having a relatively low water content (35% to 43% by weight) as described in WO 2008 / 053247. These water glasses contain organic and aqueous silica sols (at least 30% by weight of solid material) such that the molar ratio of silicon dioxide to potassium oxide is at least 4.0:1, preferably at least 4.5:1.

[0055] A refractory layer comprising potassium water glass may be "cast in place" (CIP) by introducing water glass and a hardener between adjacent plies and allowing the solution to harden until a solid interlayer is formed. CIP processes are described, for example, in U.S. Pat. Nos. 5,565,273 and 5,437,902, and WO 2008 / 053247.

[0056] The fire resistant layers may have a thickness between 0.50mm and 12.00mm. Preferably, the thickness of each fire resistant layer is between 1.00mm and 6.00mm, most preferably between 1.20mm and 4.00mm.

[0057] In some embodiments, each fire resistant layer has the same thickness, while in other embodiments, at least one fire resistant layer has a thickness that is greater (particularly 1 to 4 times, e.g., 2 times) than the thickness of at least one other fire resistant layer. A thicker fire resistant layer can be obtained, for example, by arranging the fire resistant layers so that they are provided on two plies that contact each other rather than on adjacent plies.

[0058] The fire resistant glazing may include at least one transparent plastic film between adjacent plies. Preferably, the plastic film is adjacent to the outer ply or adjacent to the innermost ply.

[0059] In some embodiments, the plastic film comprises one or more of a polyvinyl acetal such as polyvinyl butyral (PVB), ethylene vinyl acetate, an ionomer-based interlayer such as a SentryGlas® interlayer, a thermoplastic polyurethane, a polycarbonate, or an acrylic such as Uvekol®.

[0060] The thickness of the plastic film ranges from 0.1 mm to 10.0 mm, for example 0.38 mm or 0.76 mm. Suitable foils for the plastic film are commercially available.

[0061] It should be noted that such a glazing may be obtained by preparing in the manner described above an existing composite glazing formed by laminating two or more plies using one or more plastic films as outer or inner plies.

[0062] In either case, the thickness, material, and / or edge profile of the glass sheets of the composite glazing are selected to meet the relative bending stiffness requirements of the fire resistant glazing.

[0063] The fire-resistant glazing therefore consists of at least four plies, at least two fire-resistant layers and a transparent plastic film, which may also be an intermediate layer between the two plies.

[0064] The fire-resistant glazing in particular has n plies, n-(1+m) fire-resistant layers and m plastic films, where n is an integer from 4 to 20, for example 7, 11 or 13, and m is an integer from 1 to 5, for example 1, 2 or 3, with the proviso that n-(1+m) is at least 2.

[0065] In some embodiments, the fire resistant glazing has four glass plies, two fire resistant layers and a transparent plastic film, five glass plies, three fire resistant layers and a transparent plastic film, six glass plies, four fire resistant layers and a transparent plastic film, or seven glass plies, five fire resistant layers and a transparent plastic film.

[0066] In a preferred embodiment, the plastic film is adjacent to the outer ply or the innermost ply.

[0067] The fire resistant glazing according to the present invention may comply with A2-s1, d1 or higher as determined according to EN 13501-2 (2016).

[0068] The fire-resistant glazing may in particular comply with EI 30, EI 60, EI 90, EI 120 or EI 190 measured according to EN 1634-1 (2014), and may also comply with EW 30, EW 60, EW 90, EW 120 or EW 190 measured according to EN 1634-1 (2014).

[0069] The fire-resistant glazing may alternatively or additionally conform to A0, A15, A30, A60, B0, or B15 measured in accordance with the International Maritime Organization standard IMO A.754(18).

[0070] The fire-resistant glazing may also comply with A1-15, A1-30, A2-15 or A2-30 measured according to European Standard (Rail Vehicles) EN 45545-3.

[0071] A third aspect of the invention provides a product for a fire protection system comprising the fire resistant glazing of the first or second aspect.

[0072] Embodiments of this aspect will be apparent from the first and second aspects of the invention.

[0073] The products may provide for use as fixed glazing or for use as partial or full fire glazing in fire doors, walls, roofs, floors, bulkheads, or within vehicles.

[0074] Alternatively, the product may be a semi-finished product for use with other products to provide a security facility.

[0075] The fire protection system may comprise an insulated glazing unit (IGU), such as double or triple glazing. The IGU may comprise at least one fire resistant glass according to the first or second aspect of the invention in combination with conventional laminated safety glass.

[0076] Alternatively, an IGU may comprise at least one fire resistant glazing that includes a plastic film according to the present invention and at least one fire resistant glazing that does not include a plastic interlayer.

[0077] The IGU may specifically comprise a combination of fire resistant glazing having four plies and three fire resistant layers, and fire resistant glazing having four plies, two fire resistant layers and one plastic layer.

[0078] In a fourth aspect, the present invention provides a fire protection system comprising the fire resistant glazing of the first or second aspect.

[0079] Embodiments of this aspect will be apparent from the first and second aspects of the invention.

[0080] In the following the invention will be explained in more detail with reference to the accompanying drawings. [Brief description of the drawings]

[0081] [Figure 1A] FIG. 1 shows a cross-sectional view of a fire resistant glazing according to one embodiment of the present invention. [Figure 1B] 1 shows a cross-sectional view of another particular glazing. [Figure 1C] 1 shows a cross-sectional view of another particular glazing. [Figure 2A] 1 shows a cross-sectional view of a fire resistant glazing according to another embodiment of the present invention. [Figure 2B] 1 shows a cross-sectional view of another particular glazing. [Figure 3A] FIG. 2 shows a cross-sectional view of a fire resistant glazing according to yet another embodiment of the present invention. [Figure 3B] 1 shows a cross-sectional view of another particular glazing. [Figure 4A] FIG. 2 shows a cross-sectional view of a fire resistant glazing according to yet another embodiment of the present invention. [Figure 4B] 1 shows a cross-sectional view of another particular glazing. [Figure 4C] 1 shows a cross-sectional view of another particular glazing. [Figure 5A] 4 shows a cross-sectional view of a fire resistant glazing according to a further embodiment of the invention. [Figure 5B] 1 shows a cross-sectional view of another particular glazing. [Figure 6A] FIG. 2 shows a cross-sectional view of a fire resistant glazing according to yet another embodiment of the present invention. [Figure 6B] FIG. 2 shows a cross-sectional view of a fire resistant glazing according to yet another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0082] The figure compares the construction of a fire resistant glazing according to one embodiment of the invention with that of a conventional fire resistant glazing (all plies have the same thickness).

[0083] Portions of Figures B and / or C refer to glazing having a similar overall thickness to the illustrated embodiment, but are outside the scope of the present invention.

[0084] Fire resistant glazing comprises a sandwich construction in which three or more rectangular panes of float glass (with a straight edge profile) are sandwiched between two or more fire resistant layers comprising an intumescent material and optionally a plastic film.

[0085] It should be noted that the glass sheets have the same dimensions throughout, but differ in thickness as noted above. The fire resistant layers are composed of the same sodium silicate water glass and are approximately the same thickness throughout unless otherwise noted.

[0086] Figure 1A shows a fire resistant glazing according to one embodiment of the present invention, which has four glass panes 11, 12, 13 and three fire resistant layers 14 (4x3, the outer glass panes are thicker).

[0087] Each cover glass pane 11, 12 is about 1.5 times thicker than the inner glass pane 13. The fire-resistant layers 14 are each about one-half thinner than the inner glass pane 13.

[0088] FIG. 1B shows a conventional fire resistant glazing having four glass panes 11, 12, 13 and three fire resistant layers 14 (4x3, same glass pane thickness).

[0089] Each cover glass pane 11, 12 has a thickness equal to that of the inner glass pane 13. The fire-resistant layers 14 are each approximately one-half thinner than the inner glass pane 13.

[0090] FIG. 1C shows a fire resistant glazing with three glass panes 11, 12, 13 and two fire resistant layers 14 (3x2, the inner glass pane is thicker).

[0091] Each cover glass sheet 11, 12 has the same thickness and each fire-resistant layer 14 has the same thickness. The inner glass sheet 13 has a thickness that is about 2.5 times greater than the thickness of the cover glass sheets 11, 12. The fire-resistant layer 14 is about one-fifth thinner than the inner glass sheet 13.

[0092] Table 1 below gives the total thickness (t), weight (wt), moment of resistance (W) and EI performance (transverse direction) in the fire resistance test used in DIN EN 13501 for each of these glazing examples.

[0093] It should be noted that the resistance moment of a glazing is a measure of the maximum possible bending strength of the glazing before it breaks. This moment was calculated (and is calculated here) by computer-aided calculations for fire-resistant glazing (including the frame) of the type performed by structural engineers in composite structures.

[0094] For fire safety tests, fire resistant glazing having dimensions of 1800mmx3000mm was used in UP (vertical) direction and fire resistant glazing having dimensions of 3000mmx1500mm was used in ACROSS (horizontal) direction unless otherwise specified.

[0095] For the UP tests, the fire-resistant glazing was fitted within a high-quality steel window frame with 50mm wide edges and the frame was fixed within the fire-resistant test wall along three of its four sides.

[0096] For the ACROSS test, identical fire-resistant glazing was mounted within a high-quality steel frame with edges 50mm wide. The steel frame contained cross-pieces to space the glazing 70mm apart. The frame was fixed within the fire-resistant test wall along all four of its sides.

[0097] For each fire safety test, sensors were placed in the center and corners of the quadrants of the side glass panes of the room. The eight sensors monitored temperature and cracks during the fire tests and helped determine the integrity (E) and thermal insulation (I) of the glazing.

[0098] As is well known, integrity E is a measure of the ability of a building's glazing components, such as windows or fire doors, to keep out smoke gases, and insulation I is a measure of the ability of a building's glazing components to prevent the transmission of thermal radiation.

[0099] Building glazing components may be classified using a combination of these letters and time designations, for example, a building glazing with classification E30 is capable of resisting the transmission of smoke for 30 minutes, but does not prevent the transmission of thermal radiation.

[0100] Building glazing with a classification of EI30 will resist the transmission of smoke for 30 minutes and prevent the transmission of thermal radiation for 30 minutes.

[0101] Thermal radiation penetration occurs when the average temperature of the side glass panes of the room exceeds 140K and / or their maximum temperature exceeds 180K.

[0102] Similarly, building glazing with a classification of EI45 will resist the transmission of smoke for 45 minutes and prevent the transmission of thermal radiation for 45 minutes.

[0103] Table 1 refers to two fire-resistant glazings (A and A*) shown in FIG. 1A, which differ from each other only in the thickness chosen for each fire-resistant layer 14 (about 0.1 mm).

[0104] It should be noted that although the multiple glazings have similar overall thicknesses and similar weights, the mechanical stability of each glazing in FIG. 1A is found to be at least twice as strong as the glazing in FIG. 1B.

[0105] The highest EI performance belongs to the glazing of Fig. 1A, where both cover glass panes 11, 12 are thicker than the inner glass pane 13. The lowest EI performance belongs to the glazing of Fig. 1C, even though it is more mechanically stable than any other glazing of Fig. 1. Fig. 2A shows a fire-resistant glazing according to another embodiment of the invention. This glazing comprises six glass panes 11, 12, 13 and five fire-resistant layers 14 (6x5, the outer panes are thicker).

[0106] [Table 1]

[0107] Each cover glass pane 11, 12 is about 1.5 times thicker than each inner glass pane 13. The fire-resistant layer 14 is about one-half thinner than each of the inner glass panes 13.

[0108] FIG. 2B shows a conventional fire resistant glazing with six glass panes 11, 12, 13 and five fire resistant layers (6x5, same glass pane thickness).

[0109] Each cover glass pane 11, 12 has the same thickness as each of the inner glass panes 13. The fire-resistant layers 14 are each about one-half thinner than each of the inner glass panes 13.

[0110] Table 2 below gives the total thickness (t), weight (wt), moment of resistance (W) and EI performance (transverse) in the DIN EN 13501 fire test for each of these fire resistant glazing examples.

[0111] The table refers to two fire-resistant glazings (A and A*) shown in FIG. 2A, which differ from each other only in the thickness chosen for each fire-resistant layer 14 (approximately 0.1 mm).

[0112] [Table 2]

[0113] It should be noted that although the fire-resistant glazings have similar overall thicknesses and similar weights, the mechanical stability of each of the fire-resistant glazings in FIG. 2A is found to be at least twice as great as the fire-resistant glazing in FIG. 2B.

[0114] The highest EI performance belongs to the glazing of FIG. 2A where both cover glass sheets 11, 12 are thicker than the inner glass sheet 13.

[0115] Figure 3A shows a fire resistant glazing according to yet another embodiment of the invention, which has nine glass panes 11, 12, 13 and eight fire resistant layers 14 (9x8, with the outer panes being thicker).

[0116] Each cover glass pane 11, 12 is about 1.5 times thicker than each of the inner glass panes 13. The fire-resistant layer 14 is about one-half thinner than each of the inner glass panes 13.

[0117] FIG. 3B shows a conventional fire resistant glazing having nine glass panes 11, 12, 13 and eight fire resistant layers 14 (9x8, same thickness).

[0118] Each cover glass pane 11, 12 has the same thickness as each of the inner glass panes 13. The thickness of the fire-resistant layer 14 is approximately one-half that of each of the inner glass panes 13.

[0119] Table 3 below gives the total thickness (t), weight (wt), moment of resistance (W) and EI performance (transverse) in the DIN EN 13501 fire test for each of these fire resistant glazing examples.

[0120] [Table 3]

[0121] The table refers to two fire-resistant glazings (A and A*) shown in FIG. 3A, which differ from each other only in the thickness chosen for each of the fire-resistant layers 14 (approximately 0.1 mm).

[0122] It should be noted that although the multiple fire-resistant glazings have similar overall thicknesses and similar weights, the mechanical stability of each of the fire-resistant glazings of FIG. 3A is significantly higher than the fire-resistant glazing of FIG. 3B.

[0123] Note that the highest EI performance belongs to the fire resistant glazing of FIG. 3A where both cover glass sheets 11, 12 are thicker than the inner glass sheet 13.

[0124] Figure 4A shows a fire resistant glazing according to yet another embodiment of the invention, which has three glass panes 11, 12, 13 and two fire resistant layers 14 (3x2, the outer glass pane being thicker).

[0125] Each cover glass pane 11, 12 is approximately 1.5 times thicker than the inner glass pane 13. The fire-resistant layer 14 is approximately 1.7 times thinner than the inner glass pane 13.

[0126] Figure 4B shows a conventional fire-resistant glazing similar to that shown in Figure 1B. This glass has a conventional fire-resistant glazing with three glass panes 11, 12, 13 and three fire-resistant layers 14 (3x2, same glass pane thickness).

[0127] Each cover glass pane 11, 12 has a thickness equal to that of each inner glass pane 13. The thickness of the fire-resistant layers 14 is each approximately 1.7 times less than the thickness of the inner glass panes 13.

[0128] Figure 4C also shows a fire resistant glazing similar to that shown in Figure 1C, which has three glass panes 11, 12, 13 and two fire resistant layers 14 (3x2, the outer glass pane is thicker).

[0129] Each cover glass sheet 11, 12 has the same thickness and each fire-resistant layer 14 has the same thickness. The inner glass sheet 13 has a thickness that is about 2.3 times greater than the thickness of the cover glass sheets 11, 12. The fire-resistant layer 14 is about 3.75 times thinner than the inner glass sheet 13.

[0130] Table 4 below shows the EI performance of each of these glazing examples, as well as the fire resistant glazing of Figure 1A, in the fire resistance and smoke control test EN 1634-1 (various formats).

[0131] The highest EI performance is obtained with the fire resistant glazing of FIG. 1A in which both cover glass sheets 11, 12 are thicker than the inner glass sheet 13.

[0132] Figure 5A shows a fire resistant glazing according to yet another embodiment of the invention, which has four glass panes and two layers of alkali metal silicate and a layer of polyvinyl butyral 15 (4x3, the outer glass pane being thicker).

[0133] Each cover glass sheet 11, 12 is approximately 2.6 times thicker than the inner glass sheet 13. The fire resistant layers 14 are each approximately the same thickness as the inner glass sheet 13. The PVB layer 15 is located in the center of the glazing and is approximately one-quarter thinner than the inner glass sheet 13.

[0134] [Table 4]

[0135] Figure 5B shows a conventional fire resistant glazing (4x3, same glass sheet thickness) similar to that shown in Figure 1B. The glazing has four glass sheets 11, 12, 13, two fire resistant layers 14, and a polyvinyl butyral (PVB) layer 15.

[0136] Each cover glass sheet 11, 12 has the same thickness as each of the inner glass sheets 13. The fire-resistant layers 14 are each about 2.5 times thinner than each of the inner glass sheets 13. The PVB layer 15 is located in the center of the glazing and its thickness is about 5 times thinner than each of the inner glass sheets 13.

[0137] Table 5 below shows the EI performance of each of these fire resistant glazing examples compared to the fire resistant glazing of Figures 1A and 4A in the fire resistance test of DIN EN 13501-2 (horizontal direction).

[0138] Note that the highest EI performance belongs to the fire resistant glazing of FIG. 5A where both cover glass sheets 11, 12 are thicker than the inner glass sheet 13 when the PVB layer 15 is present.

[0139] It should also be noted that the EI performance of this fire resistant glazing is better than that of the fire resistant glazing shown in FIG. 4A, but not as good as that of the fire resistant glazing in FIG. 1A.

[0140] It should also be noted that if the fire resistant glazing of FIG. 5B passes fire resistance and smoke control tests, the PVB layer 15 functions as a sufficient barrier layer.

[0141] [Table 5]

[0142] FIG. 6 shows that a fire resistant glazing according to the present invention includes a plastic layer adjacent to the outer glass pane.

[0143] FIG. 6A shows a fire resistant glazing having five glass panes 11, 12, 13, three fire resistant layers 14 and a PVB layer 15 (5x4).

[0144] Each cover glass sheet 11, 12 is about 1.5 times thicker than each of the inner glass sheets 13. Each fire resistant layer 14 is about one-half thinner than each of the inner glass sheets 13. A PVB layer 15 is located adjacent the cover glass sheet 12 of the glazing and is about one-seventh thinner than the inner glass sheets 13.

[0145] FIG. 6B shows a fire resistant glazing which has seven glass panes 11, 12, 13, five fire resistant layers 12 and a PVB layer 15 (7x6).

[0146] Each cover glass sheet 11, 12 is about 1.5 times thicker than each of the inner glass sheets 13. Each fire resistant layer 14 is about one-half thinner than each of the inner glass sheets 13. A PVB layer 15 is located adjacent the cover glass sheet 12 of the glazing and is about one-seventh thinner than each of the inner glass sheets 13.

[0147] The fire resistant glazing of Figures 5A and 6 can provide fire and impact resistant glazing. They can be used in an IGU in combination with the fire resistant glazing of Figure 1A. The fire resistant glazing of Figure 6 can be used in an IGU in combination with the fire resistant glazing of any of Figures 2A, 3A, or 4A.

[0148] From the above, it is clearly seen that the fire resistant glazing of the present invention has improved fire resistance test performance compared to conventional fire resistant glazing.

[0149] Without wishing to be bound by any particular theory, it is believed that the improved performance results from the release of built-up steam pressure from the fireproofing layer upon failure of the inner pane rather than the outer pane on the room side.

[0150] This preferential discharge to the fire side means that fire-resistant glazing, especially the larger pieces, remains mechanically stable, with little or no chipping of the outer glass panes on the interior side, and improved interior cooling performance for a longer period during a fire.

[0151] The fire resistant glazing of the present invention also improves mechanical stability during handling and installation while maintaining an acceptable weight.

[0152] Compared to conventional fire-resistant glazing, the glazing is less likely to bend and the outer glass panes are less likely to shatter, greatly reducing the chance of glass breakage during installation, for example in a door.

[0153] The fire resistant glazing of the present invention may provide impact resistance while also improving fire resistance.

[0154] References herein to the outer ply or each outer ply are references to the ply or plies that provide the outer surface of the fire resistant glazing.

Claims

1. 1. A fire-resistant glazing comprising a laminate of at least three transparent plies and at least two transparent fire-resistant layers, each fire-resistant layer being an intermediate layer between two plies, and each outer ply having a bending stiffness that is 1.5 to 15 times greater than the bending stiffness of at least one inner ply.

2. 10. The fire resistant glazing of claim 1, wherein each outer ply has a thickness that is between 0.20 mm and 16.00 mm greater than the thickness of the at least one inner ply.

3. 3. A fire-resistant glazing according to claim 1 or 2, wherein each outer ply has a thickness greater than 3.00 mm, for example 3.50 mm or 4.00 mm.

4. 2. A fire resistant glazing according to claim 1, wherein each inner ply has a thickness of between 1.50 mm and 3.00 mm, for example between 2.50 mm and 3.00 mm.

5. 2. A fire-resistant glazing according to claim 1, wherein each fire-resistant layer has a thickness of between 0.50 mm and 12.00 mm, for example between 1.20 mm and 4.00 mm.

6. The fire-resistant glazing of claim 1 , wherein the outer plies have the same thickness.

7. The fire-resistant glazing of claim 1 , wherein the inner plies have the same thickness.

8. 10. The fire-resistant glazing of claim 1, wherein the fire-resistant layers have the same thickness.

9. 10. The fire-resistant glazing of claim 1, wherein at least one fire-resistant layer has a thickness that is different from the thickness of any other fire-resistant layer.

10. 10. The fire-resistant glazing of claim 1, wherein at least one fire-resistant layer has a thickness that is twice the thickness of at least one other fire-resistant layer.

11. The fire resistant glazing of claim 1 , wherein each ply comprises a glass sheet.

12. 12. The fire resistant glazing of claim 11, wherein the glass is float glass.

13. 10. The fire resistant glazing of claim 1, wherein each fire resistant layer comprises a material having a moisture content of 20% or greater.

14. The fire resistant glazing of claim 1 , wherein each fire resistant layer comprises a hydrogel.

15. The fire resistant glazing of claim 1 , wherein each fire resistant layer comprises an intumescent material.

16. 16. Fire-resistant glazing according to any one of claims 13 to 15, wherein the fire-resistant layer further comprises an organic cooling material such as a polyol, a polysaccharide or collagen.

17. 10. The fire-resistant glazing of claim 1, comprising at least four plies, at least two fire-resistant plies and at least one transparent plastic film, said plastic film also being an intermediate layer between two plies.

18. 20. The fire resistant glazing of claim 17, wherein the at least one plastic film comprises one or more of polyvinyl acetal, ionomer, polyethylene vinyl acetate, polyurethane, polycarbonate, or acrylic.

19. 19. Fire-resistant glazing according to claim 17 or 18, wherein the at least one plastic film has a thickness of from 0.10 mm to 10.00 mm.

20. 19. A fire-resistant glazing according to claim 17 or 18, wherein at least one plastic film is in contact with the outer ply or the innermost ply.

21. 10. The fire resistant glazing of claim 1 having an overall thickness of less than 65.00 mm.

22. A product for a fire glazing system comprising the fire resistant glazing of claim 1.

23. 22. The product of claim 21, which complies with EN 13501-2, IMO A. 754(18), or EN 45545.

3.

24. 23. A fire glazing system comprising one or more fire resistant glazings or products according to claim 1 or 22.

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