FLEXIBLE, FLAME-RETARDANT COMPOSITE MATERIAL

Abstract

A flexible, flame-retardant composite material includes a fabric layer; and at least one impregnated or coated Polyvinyl Butyral (PVB) coating layer, which is integral with said fabric layer. The PVB coating layer contains 20 to 60% by weight of PVB, at least one plasticizer in an amount of 5 to 40% by weight of the coating layer, and at least one flame retardant in a total amount of 5 to 75% by weight with respect to the coating layer. A manufacturing method thereof is also described, and includes an impregnation or coating of a water-based dispersion of PVB onto the fabric layer, and a further curing.

Claims

1. A flexible, flame-retardant composite material comprising: a fabric layer; and at least one impregnated or coated Polyvinyl Butyral (PVB) coating layer, which is integral with said fabric layer; the PVB coating layer containing 20 to 60% by weight of PVB, at least one plasticizer in an amount of 5 to 40% by weight of the coating layer, and at least one flame retardant in a total amount of 5 to 75% by weight with respect to the coating layer.

2. The flexible, flame-retardant composite material according to claim 1, wherein said flame retardant is a mixture of antimony trioxide Sb.sub.2O.sub.3 and at least one halogenated organic compound as flame retardant in a total amount of 5 to 45%, by weight with respect to the coating layer, and in a ratio of 0.1 to 5, part of antimony trioxide Sb.sub.2O.sub.3 per part of halogenated organic compound.

3. The flexible, flame-retardant composite material according to claim 1, wherein said flame retardant is constituted by melamine cyanurate and ammonium polyphosphate.

4. The flexible, flame-retardant composite material according to claim 1, wherein said material is a rollable fabric.

5. The flexible, flame-retardant composite material according to claim 1, wherein the fabric is a textile-based substrate comprising fibers chosen from the group consisting of polyester, polyamide, polyacrylic, polyethylene, polypropylene, glass, wool, cotton, rayon, linen, bamboo, carbon, steel, copper, and aramid fibers and their mixtures.

6. The flexible, flame-retardant composite material according to claim 1, wherein the PVB coating layer further comprises at least one mineral flame retardant, the mineral flame retardant being present in an amount of 0 to 40% by weight with respect to the coating layer, the flame retardant being chosen from aluminum trihydrate, magnesium hydroxide, zinc borate, sodium borate, sodium metaborate, borax, huntite, hydromagnesite, and their mixtures.

7. The flexible, flame-retardant composite material according to claim 1, wherein the plasticizer is present in an amount of 5 to 25% with respect to the coating layer.

8. The flexible, flame-retardant composite material according to claim 1, wherein the plasticizer originates from recycled PVB waste.

9. The flexible, flame-retardant composite material according to claim 1, wherein the plasticizer is chosen from triethylene glycol, triethylene glycol di(2-ethylhexoate), alkyl phthalate, dibutyl maleate, dibutyl adipate, dibutyl sebacate, tris (2-ethylhexyl) phosphate, 2-ethylhexyl diphenyl phosphate, triphenyl phosphate, and their mixtures.

10. The flexible, flame-retardant composite material according to claim 1, wherein the PVB of the PVB coating layer is partially crosslinked.

11. The flexible, flame-retardant composite material according to claim 1, wherein the composite material has been manufactured by a manufacturing method comprising: Providing a fabric layer, Providing at least one water-based dispersion of PVB containing the PVB, the plasticizer, at least one crosslinker, and at least one flame retardant; Impregnating or coating at least one side of the fabric layer with the water-based dispersion of PVB; Curing the thus impregnated or coated fabric at a temperature of 100 to 200? C.

12. A manufacturing method for forming the flexible, flame-retardant composite material according to claim 1, wherein said method comprises: Providing a fabric layer, Providing at least one water-based dispersion of PVB containing the PVB, the plasticizer, at least one crosslinker, and at least one flame retardant; Impregnating or coating at least one side of the fabric layer with the water-based dispersion of PVB; Curing the thus impregnated or coated fabric at a temperature of 100 to 200? C.

13. The manufacturing method according to claim 12, wherein the PVB originates from recycled PVB waste.

14. The manufacturing method according to claim 12, wherein a drying step is carried out after the impregnation step and before the curing step.

15. The manufacturing method according to claim 12, wherein the crosslinker is chosen from blocked isocyanates, isocyanates, carbodiimides and their mixtures, and is present in an amount from more than 0% up to 20% by weight based on the weight of the PVB polymer in the water-based dispersion.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0098] The way of carrying out the invention as well as the advantages thereof will become apparent from the following description, made by way of non-limiting indication and with the aid of the accompanying drawings, in which:

[0099] FIG. 1 is a perspective view of a flexible sheet constituting a first embodiment of the invention.

[0100] FIG. 2 is a perspective view of a flexible sheet constituting a second embodiment of the invention.

[0101] FIG. 3 is a cross section of a first apparatus for the manufacture of a flexible sheet according to the invention.

[0102] FIG. 4 is a cross section of a second apparatus for the manufacture of a flexible sheet according to the invention.

[0103] FIG. 5 is a cross section of a third apparatus for the manufacture of a flexible sheet according to the invention.

DETAILED DESCRIPTION

[0104] Identical numbers denote identical parts.

[0105] FIG. 1 is a perspective view of a flexible sheet 1 constituting a first embodiment of the invention. The flexible sheet 1 comprises a fabric layer 11 coated on both sides by a PVB coating layer 10.

[0106] FIG. 2 is a perspective view of a flexible sheet 2 constituting a second embodiment of the invention. The flexible sheet 2 comprises a fabric layer 11 coated on both sides by a PVB coating layer 10, the side to be in contact with the outdoor atmosphere being further coated by a top-coat layer 12. This top-coat layer 12 is a clear coat.

[0107] FIG. 3 is a cross section of a first apparatus 3 for the manufacture of a flexible sheet 39 according to the invention. The apparatus 3 can typically be used for both mesh fabrics and plain fabrics, especially fabrics of large width. The arrows indicate the direction of circulation of the sheet. A fabric 29 is unwound from a roll 28, and further guided by rolls 33. The fabric is impregnated in a bath 30 of liquid PVB present in a container 31. Two scrapers 22 remove excess 32 of PVB which fall down in the bath. The coated fabric 36 is then guided, optionally passed next to a nozzle 20 which blows air by micro jets to clean the holes in the coated fabric 36 if necessary (for example in the case of a mesh fabric if the holes of the mesh fabric are of dimension less than 5 mm), to an oven 25 which allows the drying and crosslinking and thus leads to obtaining the flexible sheet 29. The flexible sheet 29 comprises no crosslinker once the heat-induced chemical reaction is complete.

[0108] FIG. 4 is a cross section of a second apparatus 4 for the manufacture of a flexible sheet 40 according to the invention. The apparatus 4 can typically be used for mesh fabrics. The arrows indicate the direction of circulation of the sheet. The fabric 29 is unwound from the roll 28, further impregnated in the bath 30 of liquid PVB present in the container 31 and guided by the transfer roll 42 which transfers the coating onto the mesh fabric 29. The following rollers 34 transfers the liquid coating between both sides of the mesh fabric back and forth and ensure an equal, uniform coating of both sides and the inner surface of the mesh fabric. The coated fabric 37 is then guided optionally passed next to a nozzle 21 which blows air by micro jets to clean the holes in the coated fabric 37 if necessary (for example if the holes of the mesh fabric are of dimension less than 3 mm), to an oven 26 which allows the drying and crosslinking and thus leads to obtaining the flexible sheet 40.

[0109] FIG. 5 is a cross section of a third apparatus 5 for the manufacture of a flexible sheet 41 according to the invention. The apparatus 5 can typically be used for plain fabrics. The arrow indicates the direction of circulation of the sheet. The fabric 29 is unwound from the roll 28, and the liquid PVB 30 is spread onto the fabric 29 using a doctor blade 24. During the knife coating step, the fabric 38 is stabilized by a support roll 35. Afterwards it enters an oven 27 which allows the drying and crosslinking and thus leads to obtaining the flexible sheet 41.

EXAMPLES

[0110] 8 examples, among which 3 comparative examples and 5 examples according to the invention, were carried out.

[0111] First, the components of the compositions of the 8 different PVB coating layers are summarized in Tables 1 and 1a below, and the related ratios when needed in Table 2 below.

[0112] These 8 compositions were used in a manufacturing corresponding the one disclosed in FIG. 3. The 6 first compositions used the same fabric layer which is made of woven PES spun yarn and has a weight per area of about 125 g/m2. The 7.sup.th composition used other fabric layer: 100% PET mesh fabric 110 g/qm coated both side (the weight after coating was 250 g/qm). The 8.sup.th composition used still another fabric: 100% PET fabric 200 g/qm, closed structure (the weight after coating was 450 g/qm).

[0113] The drying was carried out for 1 minute at 80? C. followed by a curing step for 2 minutes at 150? C.

[0114] The properties of the thus obtained composite materials were tested according to the standard, except weldability which was measured using a stationary high frequency (HF-) welding machine manufacturesd by Forsstrom, Sweden, model type Forsstrom XP 160. Pressure: 3.0 kg/cm.sup.2. Welding time: 6 s. Welding current: 0.55 A. Cooling time: 8 seconds. The results are summarized in Table 3 below.

TABLE-US-00001 TABLE 1 composition (part on top of 100 parts of resin dispersion) Example no 1 2 3 4 5 6 7 8 Comp Inv Comp Inv Comp Inv Inv Inv Aqueous PVB 100 100 100 100 100 100 100 100 dispersion (Shark dispersion SX1) UV filter 1 1 1 1 1 1 1 1 (Uvinul 3039) Crosslinker: 0 3 3 3 3 3 2 2 blocked isocyanate (Imprafix 2794) Mineral flame 50 50 50 50 0 0 30 50 retardant: ATH powder (Alfrimal 104D) Flame 40 40 0 50 0 60 0 0 retardant component: comprising Br/Sb.sub.2O.sub.3, 1 part of Sb.sub.2O.sub.3 per 3 parts of brominated agent (Flacavon FH 9004/123) White pigment 15 15 15 15 15 15 15 15 TiO.sub.2 (Tubiprint weiss K90) Phosphate 0 0 0 0 0 0 10 10 plasticizer (Addiflam SR10) Melamine 0 0 0 0 0 0 15 10 cyanurate (Addiflam pow MCA Eco) Coated 0 0 0 0 0 0 40 30 ammonium polyphosphate (Aflammit TLP 1630) Where Comp means comparative and Inv means Invention

TABLE-US-00002 TABLE 1a composition (in % in the dried coating before curing) Example no 1 2 3 4 5 6 7 8 Comp Inv Comp Inv Comp Inv Inv Inv PVB 27 26.8 33.3 25.5 61.8 36.8 23 22 TEG-EH 8.5 8.5 10.5 8.1 19.5 11.6 7.3 7 UV filter 0.7 0.7 0.9 0.7 1.7 1.0 0.6 0.6 Crosslinker: 0 0.7 0.8 0.6 1.5 0.9 0.4 0.4 blocked isocyanate Mineral flame 37.3 37.1 46.1 35.4 0 0 19 32 retardant: ATH Sb.sub.2O.sub.3 4.9 4.9 0 5.8 0 10.1 0 0 brominated 14.8 14.7 0 17.5 0 30.3 0 0 agent TiO.sub.2 6.7 6.7 8.3 6.4 15.4 9.2 7.7 7.1 Phosphate 0 0 0 0 0 0 6.5 6.1 plasticizer MCU 0 0 0 0 0 0 10 6.5 Coated APP 0 0 0 0 0 0 25.5 18.3

TABLE-US-00003 TABLE 2 ratios (Sb as Sb.sub.2O.sub.3, Br as the brominated organic compound) Example no 1 2 3 4 5 6 Comp Inv Comp Inv Comp Inv Ratio PVB 5.5:1 5.5:1 N/A 5.5:1 N/A 3.6:1 on Sb Ratio PVB 1.4:1 1.4:1 N/A 1.4:1 N/A 0.9:1 on (Sb + Br) Ratio (PVB + 7.2:1 7.2:1 N/A 7.2:1 N/A 4.8:1 plasticizer) on Sb) Ratio (PVB + 1.8:1 1.8:1 N/A 1.8:1 N/A 1.2:1 plasticizer) on (Sb + Br) Where Comp means comparative, Inv means Invention and N/A means not applicable or not defined (not calculable)

[0115] Examples 1 to 6 relate to use of the same flame retardant component (brominated organic compound+antimony trioxide), according to a first embodiment of the invention.

[0116] It can be seen that examples 1 and 2 were carried out modifying only the content of crosslinker (blocked isocyanate, cells in bold), examples 3 and 4 were carried out modifying only the content of the flame retardant component (brominated organic compound+antimony trioxide, cells in bold), some ATH as mineral flame retardant being present, and examples 5 and 6 were carried out modifying only the content of the flame retardant component (brominated organic compound+antimony trioxide, cells in bold), no mineral flame retardant being present.

[0117] Examples 2, 4 and 6 (respectively Inv 2, Inv 4 and Inv 6) correspond to cases according to the invention wherein all the ratios PVB on Sb, PVB on (Sb+Br), (PVB+plasticizer) on Sb and (PVB+plasticizer) on (Sb+Br) are inside the preferred ranges.

[0118] Comparative example 1 (Comp 1) correspond to a case where the composite material does not comprise any crosslinker during the manufacturing process; therefore, the PVB is not partially crosslinked.

[0119] Comparative example 3 (Comp 3) correspond to a case where the composite material does not comprise any flame retardant component comprising Br/Sb.sub.2O.sub.3.

[0120] Comparative example 5 (Comp 5) correspond to a case where the composite material does not comprise any flame retardant component comprising Br/Sb.sub.2O.sub.3.

[0121] Examples 7 and 8 (respectively Inv 7 and Inv 8) relate to use of another mixture of flame retardant (phosphate plasticizer+melamine cyanurate+coated ammonium phosphate+ATH), according to a second embodiment of the invention.

TABLE-US-00004 TABLE 3 results of the tests Example no 1 2 3 4 5 6 7 8 Comp Inv Comp Inv Comp Inv Inv Inv HF weldability YES YES YES YES YES YES YES YES Flexibility FAIL PASS Not tested PASS PASS PASS N/A PASS Fire retardancy, B2 PASS PASS FAIL PASS FAIL PASS PASS PASS

[0122] It can be seen that examples 2, 4, 6, 7 and 8 according to the invention are the only examples fulfilling all the requirements in particular in terms of flame retardant properties.

[0123] Comp 1 shows a good weldability. However, due to the lack of crosslinker, the coating is not durable enough and shows not sufficient adhesion to the textile substrate.

[0124] Comp 3 demonstrates that even a high load of a mineral flame retardant like ATH is not sufficient in order to get the desired flame retardancy properties.

[0125] If no Sb.sub.2O.sub.3 nor ATH is present, nor any other flame retardant according to the invention, Comp 5 demonstrates that it is not possible to get the desired flame retardancy properties.