FLOOR COVERING WITH FIREPROOF WEAR LAYER

Abstract

The present invention relates to a multi-layer floor covering comprising, from the base to the top of the covering: a back layer A, a decorative layer B, a surface layer C,
the decorative layer B being advantageously in the form of a printed substrate or an ink layer printed on the back layer A or on the back of the surface layer C,
the surface layer C comprising: a polymer matrix comprising polyvinyl chloride, and a mineral filler comprising hydrotalcite, the hydrotalcite being used as fireproofing and having a rate of incorporation, by weight, in the polymer matrix that is greater than or equal to 3%, preferably greater than or equal to 5%.

Claims

1. A multi-layer floor covering comprising, from the base to the top of the covering: a back layer A, a decorative layer B, a surface layer C, wherein the surface layer C comprises: a polymer matrix comprising polyvinyl chloride, and a mineral filler comprising hydrotalcite, the hydrotalcite being used as a flame retardant and representing at least 3%, relative to the weight of the surface layer C.

2. The multi-layer floor covering according to claim 1, wherein the surface layer C comprises polyvinyl chloride and hydrotalcite.

3. The multi-layer floor covering according to claim 1, wherein the hydrotalcite represents from 5% to 50% by weight relative to the weight of the surface layer C.

4. The multi-layer floor covering according to claim 1, wherein the hydrotalcite represents from 9% to 33% by weight relative to the weight of the surface layer C.

5. The multi-layer floor covering according to claim 1, wherein the hydrotalcite is of the type [MII1−x MIIIx (OH)2] [An−x/n, yH2O], with: MII being a divalent metal cation comprising Mg2+ and/or Zn2+, MIII being an Al3+ trivalent metal cation, An−: anions, x: charge density, of between 0.2 and 0.33, y being between 0 to 10, n being between 1 to 3.

6. The multi-layer floor covering according to claim 1, wherein the hydrotalcite is in the form of particles with a size of between 200 nm and 1 μm.

7. The multi-layer floor covering according to claim 1, wherein the polyvinyl chloride of the polymer matrix comprises plasticised polyvinyl chloride.

8. The multi-layer floor covering according to claim 1, wherein the surface layer C has a thickness of between 0.1 mm and 2 mm.

9. The multi-layer floor covering according to claim 1, wherein the back layer A comprises a polymer selected from the group consisting of polyvinyl chloride, ethylene vinyl acetate copolymer, and mixtures thereof.

10. The multi-layer floor covering according to claim 1, wherein the multi-layer floor covering comprises, from its base towards its top: a fibrous reinforcing layer A′ comprising polyester non-woven fabric or glass fibers, an adhesive layer B′, the back layer A comprising polyvinyl chloride, the decorative layer B, the surface layer C comprising.

11. A method of manufacturing the multi-layer floor covering according to claim 1, comprising the following steps: manufacturing the back layer A, decorative layer B and surface layer C, and assembling said back layer A, decorative layer B, and surface layer C.

12. The method according to claim 11, further comprising: manufacturing the fibrous reinforcing layer A′ and adhesive layer B′, and assembling said fibrous reinforcing layer A′ and adhesive layer B′, to form the multi-layer floor covering.

13. The multi-layer floor covering according to claim 1 wherein the hydrotalcite being is representing at least 5%, relative to the weight of the surface layer C.

14. The multi-layer floor covering according to claim 1, wherein the hydrotalcite is in the form of particles with a size of between 400 μm and 700 μm.

15. The multi-layer floor covering according to claim 1, wherein the decorative layer B is in the form of a printed substrate or an ink layer printed on the back layer A or on the back of the surface layer C.

Description

DESCRIPTION OF THE FIGURES

[0151] The following figures are provided as illustrative and non-limiting examples:

[0152] FIG. 1 is a diagram of a floor covering according to the invention, comprising a back layer A, a decorative layer B, and a surface layer C.

[0153] FIG. 2 is a diagram of a floor covering according to the invention, comprising a back layer A, a decorative layer B, and a surface layer C, as well as an underlying fibrous reinforcing layer A′ and an adhesive layer.

DETAILED DESCRIPTION OF THE INVENTION

[0154] Several multi-layer coatings referenced M1 to M10 have been manufactured.

[0155] The coverings M1 to M10 differ only in the nature of their surface layer C, and comprise the same back layers A, decorative layers B, and adhesive layers H making it possible to bond said back layer A with decorative layer B, namely: [0156] a back layer A: 100% PVC+plasticiser+mineral fillers, 1.5 mm thick; [0157] adhesive layer H: copolyamide hot-melt film (coPA), marketed under the reference TC203 by PROCHIMIR; [0158] decorative layer B: complex comprising a glass grid and a polyester non-woven fabric, coated with a pattern applied by digital printing.

[0159] The surface layers C of the coverings M1 to M10 are all 0.45 mm thick, and have the following compositions: [0160] M1: PVC plasticised to 38 per with a phosphate plasticiser marketed under the reference Santicizer 141 (S141) by Valtris; the acronym “per” means “percent resin”, it is the quantity (by weight) of plasticiser per 100 parts of resin consisting of PVC and the plasticiser. In the case of the covering M1, the resin consists of 38 parts by weight of Santicizer 141 plasticiser per 100 parts by weight of resin; —M2: PVC plasticised to 38 per with a phosphate plasticiser marketed under the reference Sanitiser 148 (S148) by Valtris; —M3: PVC plasticised with a mixture of two plasticisers marketed respectively under the reference S141 (19 per) and Cereclor S45 (C45) by Ineos (19 per); —M4: PVC plasticised to 38 per with plasticiser S141, additivated with 9% by weight of pyrogenic silica Evonik Aerosil R805; —M5: PVC plasticised to 38 per with plasticiser S141, additivated with 5% by weight of magnesium hydroxide Mg(OH).sub.2 (MDH) of grade Magnifin H10 from Huber; —M6: PVC plasticised to 38 per with plasticiser S141, additivated with 9% by weight of hydrotalcite no. 1 (HDT-1) of Mg—Zn—Al type; —M7: PVC plasticised to 38 per with plasticiser S141, additivated with 23% by weight of hydrotalcite no. 1 (HDT-1) of Mg—Zn—Al type; —M8: PVC plasticised to 38 per with plasticiser S141, additivated with 33% by weight of hydrotalcite no. 1 (HDT-1) of Mg—Zn—Al type; —M9: PVC plasticised to 38 per with plasticiser S141, additivated with 33% by weight of hydrotalcite no. 2 (HDT-2) of Mg—Al type; —M10: PVC plasticised to 38 per with plasticiser S141, additivated with 33% by weight of hydrotalcite of grade 5944 no. 3 (HDT-3) of Mg—Zn—Al type.

[0161] Two 75 mm×75 mm covering samples are produced for each of the coverings M1 to M10. These test pieces are bonded to a 1 mm aluminium substrate with Bostik ISR 7007 adhesive (300 g/m.sup.2). After drying the adhesive and conditioning, the samples are tested in a smoke chamber according to the ISO 5659-2 test method in accordance with the R10 requirement of EN45545 (rail transport standard), and then the following are determined: [0162] the density of the smoke (smoke no. 1 and smoke no. 2), which provides an average smoke density for these 2 tests (average smoke); [0163] the gas toxicity index (ITCg) 4 minutes after the start of the test (tox 4 min no. 1 and no. 2), and 8 minutes after the start of the test (tox 8 min no. 1 and no. 2), which provides an average toxicity at 4 minutes (average 4 mins tox) and 8 minutes (8 mins average tox).

[0164] The ISO 5659-2 standard corresponds to a fire test in a smoke chamber. The samples are subjected to a radiative flux of 25 kW/m.sup.2 with pilot flame. The optical density of the smoke is monitored for 20 mins (duration of the test), and the toxicity of the gases is measured following two sampling sessions which take place at 4 mins and 8 mins after the start of the test.

[0165] The results obtained are indicated in Table 1 below:

TABLE-US-00001 TABLE 1 Smoke density and toxicity values Coating M1 M2 M3 M4 M5 M6 M7 M8 M9 M10 Layer C PVC PVC PVC PVC PVC PVC PVC PVC PVC PVC S141 S148 S141 S141 S141 S141 S141 S141 S141 S141 C45 Silica MDH HDT-1 HDT-1 HDT-1 HDT-2 HDT-3 9% 23% 33% 33% 33% Layer B Complex + pattern by digital printing Layer H Hot-melt film coPA Layer A flame retardant PVC formula Smoke nº1 364 357 419 288 313 195 183 176 202 231 Smoke nº2 330 342 413 297 320 180 146 212 175 204 Smoke 347 350 416 293 317 188 165 194 189 218 (average) Tox 4 min 0.34 0.73 1.07 0.66 0.69 0.66 0.18 0.34 0.48 0.22 nº1 Tox 4 min 0.41 0.37 0.88 0.64 0.73 0.58 0.39 0.25 0.32 0.26 nº2 Tox 4 min 0.38 0.55 0.98 0.65 0.71 0.62 0.29 0.30 0.40 0.24 (average) Tox 8 min 0.4 0.6 0.76 0.63 0.54 0.57 0.24 0.38 0.47 0.24 nº1 Tox 8 min 0.35 0.28 0.65 0.47 0.51 0.48 0.31 0.26 0.3 0.28 nº2 Tox 8 min 0.38 0.44 0.71 0.55 0.53 0.53 0.28 0.32 0.39 0.26 (average)

[0166] From these results, it can be seen that the coverings M1, M2, M3, M4, and M5 of the state of the art are not satisfactory because the average smoke density value is greater than 300 (which corresponds to the maximum smoke density acceptable for requirement HL2 of standard EN45545), except for the M4 covering, the average smoke density value of which is however 293, i.e., very close to the threshold value of 300.

[0167] In contrast, the coverings M6, M7, M8, M9 and M10 of the invention are satisfactory both for the smoke density (the average smoke density value is less than 200 or very close to 200 for the covering M10), than for the toxicity of gases (the average toxicity values at 4 minutes and 8 minutes are less than 0.90, the maximum toxicity for the HL2 requirement).

[0168] In particular, by comparing the M6 covering (9% hydrotalcite) with the control covering M1, it can be seen that the presence of hydrotalcite in the surface layer decreases by (347-188)/347=45% of the smoke density from 9% of the loaded weight of the surface layer C.

[0169] The performances are even better in terms of the 23% hydrotalcite in the surface layer C, both for the average density of the smoke (165 for M7 against 188 for M6) and for the average toxicity of the smoke (0.29 for M7 against 0.62 for M6 at 4 minutes, and 0.28 for M7 against 0.53 for M6 at 8 minutes).

[0170] The performances remain excellent and similar overall, with 33% hydrotalcite in the surface layer C: M8, M9 and M10 coverings. However, the surface layer C is slightly yellowed.

[0171] The surface layers C of the coverings M1, M2, M3, M6, M7 and M8 have a transparency which is acceptable for industrial application. The M4 covering is slightly blue, the M5 covering is slightly opaque, and the M9 and M10 coverings are transparent but have a more yellowish colour.