Non-Combustible, Breathable Membrane

Abstract

A coated textile contains a web based on glass fibres having a back face, a front face and at least one edge. The front face is covered with a coating layer based on silicone and back face is capable of being bonded to a support. The coating layer has a thickness between 5 μm and 250 μm and includes at least one inorganic flame retardant compound in a quantity which is sufficient for the coated textile to have a gross calorific value of less than or equal to 3 MJ/kg, the inorganic flame retardant compound having a D50 granule size of less than 50 μm.

Claims

1. A coated textile containing a web based on glass fibres having a back face, a front face and at least one edge, said front face being covered with a coating layer based on silicone and said back face being capable of being bonded to a support, said coating layer having a thickness between 5 μm and 250 μm and comprising at least one inorganic flame retardant compound in a quantity which is sufficient for the coated textile to have a gross calorific value of less than or equal to 3 MJ/kg, the inorganic flame retardant compound having a D50 granule size of less than 50 μm.

2. The coated textile according to claim 1, wherein the web has a thickness between 20 μm and 1 mm.

3. The textile according to claim 1, wherein the web has a weight between 20 g/m.sup.2 and 1000 g/m.sup.2.

4. The textile according to claim 1, wherein the coating layer covers the edge of the web based on glass fibres.

5. The textile according to claim 1, wherein the back face of the web based on glass fibres is covered with a coating layer.

6. The textile according to claim 5, wherein the coating layers covering the front and back faces are based on the same material.

7. The textile according to claim 5, wherein the thickness of the coating layer covering the back face is less than the thickness of the coating layer covering the front face.

8. The textile according to claim 1, wherein the silicone is selected from the group comprising polydimethylsiloxanes, polydiphenylsiloxanes, oligosiloxanes, polyaminosiloxanes, polyvinylsiloxanes and their copolymers.

9. The coated textile according to claim 1, wherein said inorganic flame retardant compound is selected from the group comprising aluminium trihydrate, magnesium hydroxide, silicas, zeolites, zinc hydroxystannate, calcium hydroxystannate, antimony trioxide, calcium carbonate, inorganic pigments and metallic fillers, such as aluminium or copper.

10. The textile according to claim 1, wherein said coating layer comprises between 5% and 70% by weight of at least one inorganic flame retardant compound.

11. A process for the production of a textile according to claim 1, comprising at least the following steps: obtaining a woven or nonwoven web based on glass fibres, coating said front face with a silicone-based composition comprising between 5% and 70% by weight of at least one inorganic flame retardant compound.

12. The process according to claim 11, wherein the coating step is carried out in the aqueous base type liquid phase or in a more viscous LSR, RTV type phase.

13. Use of the textile according to claim 1, as a covering for a structure of a building.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0056] The manner of carrying out the disclosed embodiemtns as well as the advantages accruing to them will become apparent from the following description of embodiments made with the aid of the accompanying drawings, in which:

[0057] FIG. 1 is a cross section of one embodiment of a textile,

[0058] FIG. 2 is a cross section of two textiles of the figure assembled together;

[0059] FIG. 3 is a cross sectional view of the textile of FIG. 1 associated with a support;

[0060] FIG. 4 is a cross section of another embodiment of a textile.

[0061] Clearly, the dimensions and the proportions of the elements illustrated in FIGS. 1 and 2 have had to be exaggerated with respect to reality and have only been given with the aim of facilitating comprehension of the disclosed embodiments.

DETAILED DESCRIPTION

[0062] The embodiment of the coated textile 1 illustrated in FIG. 1 comprises a web 2 based on woven glass fibres. The web 2 has a front face 3, a back face 4 and edges 5, 6. The web 2 is covered with a coating layer 7 based on silicone at the level of the front face 3 and the edges 5, 6.

[0063] In this configuration, the thickness of the coating layer 7 is sufficient to ensure good protection of the coated textile 1 in the event of bad weather, such as heavy rain, at the edges 5 and 6 in particular, and is sufficient to guarantee strength and fire resistance while providing the coated textile 1 with a waterproof breathable nature.

[0064] The back face 4 of the web 2 is not coated, which means, as already indicated above, that any technique can be used with a view to attaching the coated textile 1 to a façade of a building.

[0065] FIG. 2 illustrates an assembly 8 of two panels in accordance with the embodiment illustrated in FIG. 1. In practice, a first textile 1 is positioned facing a second textile 21 in a manner such as to have an overlapping zone 15. The two panels 1 and 21 are then attached at this overlapping zone by interposing a line of adhesive 20 which comes into contact with the coating layer 7 of the first panel 1, and the back face 24 of the second power 21. Thus, the assembly 8 is impermeable, in particular at the level of the edge of the panel intended to be exposed to the exterior, or more generally to an atmosphere containing liquid moisture, and the physical properties of this assembly are substantially similar to those of the coated textiles 1 and 21.

[0066] FIG. 3 illustrates the association of a textile sheet 1 with a support 30, which may be a layer of an insulating material such as rockwool or glass wool; via a layer 31 which is advantageously heat-reactivatable, present on all or a portion of the facing surfaces.

[0067] In a variation illustrated in FIG. 4, the textile 40 includes a woven core 42 which is equivalent to that of FIG. 1. The front face 43 of this core is covered with a first coating layer 47, and on its back face 44 is a second coating layer 48.

EXAMPLES

[0068] Coated textiles were produced from fabrics based on woven glass fibres and with different coating compositions. More precisely, the fabric was obtained with glass yarns which had been Z twisted at 40 twists/m; with a warp and weft density of 680 dtex. These yarns were woven in a proportion of 16 and 16.5 yarns per centimetre in the respective warp and weft directions, in accordance with a 4-harness satin weave.

[0069] The characteristics of the various textiles are summarized in Table 1.

TABLE-US-00001 TABLE 1 Granule size Quantity of of inorganic inorganic Specimen Coating Inorganic compound compound number layer compound (D50) (% dry matter) 1 Silicone Aluminium 2 μm 45 (disclosed trihydrate embodiment) 2 Silicone Aluminium 16 μm  55 (disclosed trihydrate embodiment) 3 Silicone None — — (contrasting example) 4 Acrylate Antimony 2 μm 25 (contrasting trihydrate example)

[0070] These coated textiles underwent a dynamic impermeability test before and after ageing, a static impermeability test, a breathability test, an adhesive breaking test, and a crease fold test. The GCV of each textile was also measured. The results are summarized in Table 2.

[0071] The dynamic permeability of water was measured in accordance with the standard EN 20811; a textile is sufficiently impermeable if the result of the water column test is more than 100 cm. The dynamic water column test can be used to quantify the impermeability of a product which is subjected to a gradual increase in pressure from a 60 cm column of water per min, denoted 60 cmWS/min. The test face was coated with the membrane and covered a surface area of 100 cm.sup.2. The test had a target value which was defined by the user and the test was stopped as soon as it was reached. However, the test could have been stopped prematurely after three droplets became visible on the back of the membrane. The value in cm on the column corresponding to the third appearance was noted.

[0072] The specimens were subjected to ageing by placing them in an oven at 120° C. for one week. They were then tested in accordance with the above dynamic water column protocol.

[0073] In contrast to the measurement of the dynamic impermeability, wherein the pressure was varied by ramping it up, the measurement of the static impermeability (W1 test) employed a constant pressure procedure provided by a 20 mbar column of water. The test lasted two hours. The device was constituted by a reservoir of water, coloured to make it visible. The membrane was placed on top. A filter paper covered the top in order to provide evidence of the passage of water through the membrane and thus betray the non-permeability of the product. A plate of plexiglass was then deposited in order to prevent explosion phenomena due to the pressure. The result of the test is binary: either the product reaches the W1 classification, or it does not satisfy these conditions.

[0074] The breathability was measured in accordance with the standard EN ISO 12572-C/DIN 1931. The breathability was evaluated by comparison with a parameter for resistance to the diffusion of vapour (Sd), which corresponds to the diffusion-equivalent air layer thickness (in metres). This parameter was calculated from the transmission rate for water vapour (WVRT, for Water Vapour Rate of Transmission), expressed in g/m.sup.2/day, and depended on the thickness of the material. A textile was considered to be sufficiently breathable if the parameter Sd is less than 0.2 m.

[0075] It was evaluated by gravimetric measurement under moist conditions. The membrane was installed above a cup filled with a standardized quantity of water, then placed in a precisely controlled climatic chamber. The measurement was available after a few hours; the time varied as a function of the thickness of the product.

[0076] The adhesive breakage was measured in accordance with the standard EN 12311-1. The bonded assemblies were placed in an oven at 200° C. for 8 hours. It was a joint with a single covering of the adhesive device adapted to the application. The specimens were produced in a shear-tensile configuration. They were cut to a width of 5 cm and a length of 20 cm and were tested on a standardized tensile test bench. The breaking force of the adhesive was then measured in N/5cm. The bond was considered to be satisfactory if breaking occurred above 200 N/5cm.

[0077] The breaking strength after crease fold was measured in accordance with the standard ASTM D 4851. Glass textile membranes (5 cm width and 20 cm length) were pre-folded in accordance with specific conditions: the membrane was folded back on itself before being subjected to a pressure on its surface, repeated ten times by means of a roller, always in the same direction. The back face-to-the back face was tested as well as the front face-to-the front face.

[0078] The GCV was measured in accordance with the standard EN ISO 1716 with the “bomb calorimeter” method. The value for the GCV (gross calorific value) determines the role that the product could play in a fire. It is measured using a bomb calorimeter. A small amount of the material was placed in a crucible with a combustible agent. This was all placed in the bomb calorimeter filled with pure dioxygen. It was closed and placed in a thermostated bath the temperature of which was known and fixed. The bomb calorimeter was triggered; the principle of the measurement resides in the difference in temperature between the water of the bath before the reaction and after the reaction due to the energy of combustion. The final value for the GCV was provided in MJ/kg. As already mentioned, the desired GCV is a GCV of 3 MJ/kg or less.

TABLE-US-00002 TABLE 2 Adhesive Dynamic breaking Breaking Dynamic impermeability Static @200° C., after crease impermeability after ageing impermeability WVRT 8 hours fold GCV Specimen (cm) for 1 week at (W1 or not) Sd (m) ((g/m.sup.2)/day) °(N/5 cm) (N/5 cm) (MJ/kg) Standard EN Using EN EN EN ISO EN ISO Using EN ASTM EN 20811 20811 1928 12572- 12572- 12311-1 D485.1 1716 C/DIN C/DIN 1931 1931 1 >300 >300 W1 0.16 143 >600 >1000 2.75 2 >300 >300 W1 0.18 126 >600 >1000 2.45 3 >300 >300 W1 0.32 75 >600 >1000 >4.5 4 <60 <10 No W1 0.08 255 504-616 400 4.54

[0079] The various tests show that the membranes produced with a textile in accordance with the disclosed embodiments (specimens 1 and 2) have a GCV of less than 3 MJ/kg, while having impermeability, waterproofing and breathability and mechanical properties that mean that they can be used as a covering for a wall of a building, while the membranes produced with a textile with a coating layer not comprising the inorganic flame retardant compound (specimen 3) or based on acrylate (specimen 4) did not have the desired set of properties.