Multi-layer structure for creating a reinforced and recyclable floor covering

Abstract

The invention relates to a multilayer structure (1) for producing a floor covering, comprising at least one surface layer (2) bonded to a backing layer (3), the surface layer (2) and the backing layer (3) being made from PVC; characterized in that the multilayer structure (1) comprises a surface mass of between 1500 and 2500 g / m², and a woven reinforcement (5) bonded to the surface layer (2) and to the backing layer (3) by means of bonding layers (6) in the form of hot-melt or copolyester films, or layers of cross-linked polyurethane adhesive; and in that the backing layer (3) made from PVC comprises: - a thickness of between 150 µm and 600 µm; - less than 15 PCR of plasticizer. Figure for the abstract: Fig. 3

Description

Title of the invention: Multi-layer structure for the production of a reinforced and recyclable floor covering Technical field

[0001] The invention relates to the technical field of flexible floor coverings, preferably presented in rolls or in the form of a welded and adhesive kit.

[0002] The invention relates to a multi-layer structure for producing a reinforced and recyclable floor covering.

[0003] The invention finds an advantageous application for coating honeycomb aircraft floor panels for example. Prior art

[0004] A multi-layer structure for producing a floor covering is well known in the prior art, comprising a surface layer bonded to a so-called "laminated" backing layer used to cover aircraft floors, for example.

[0005] In this type of structure, the laminated backing layer consists of a woven reinforcement of glass fibers impregnated with phenolic or polyester resins. This backing layer ensures that the floor covering is held on its support, provides dimensional stability, blocks the migration of plasticizers from the PVC surface layers, and improves the impact resistance of the floor covering.

[0006] The laminated backing layer is complex to manufacture and requires a certain technical mastery, for which a limited number of companies have the skills, which implies a high production cost.

[0007] Another disadvantage of this laminated backing layer is that it is not recyclable due to the use of phenolic resin. To date, production waste from flooring containing this type of layer is generally discarded.

[0008] Documents US2010 / 0227132 and EP3064347 are known from the prior art, which describe multi-layer structures for producing floor coverings in which a backing layer is composed of a composite material comprising woven or non-woven reinforcing fibers and a thermosetting or thermoplastic polymer resin, chosen from the group comprising polyester resin; phenolic resin; epoxy resin; polysulfone; vinylester resin; epoxy-acrylic resin; and mixtures thereof.

[0009] The resulting disadvantage is that the use of a thermosetting resin affects the recyclability of the floor covering.

[0010] Replacing phenolic resin with a thermoplastic resin may affect also recyclability, because the structure becomes too heterogeneous. In addition, the expected performances of the multi-layer structure are not achieved, such as weldability between two structures or resistance to traffic for example. Statement of the invention

[0011] One of the aims of the invention is therefore to overcome the drawbacks of the prior art by proposing a multi-layer structure, for example used to cover aircraft floors, having a backing layer whose manufacturing cost is low compared to that of laminated layers, and to provide a multi-touch structure giving complete satisfaction in terms of the hold of the covering on its support, dimensional stability, and impact resistance of the floor covering.

[0012] Another objective of the invention is to provide such a multilayer structure whose recyclability is improved.

[0013] For this purpose, a multi-layer structure has been developed for producing a floor covering, comprising at least one surface layer bonded to a backing layer, the surface layer and the backing layer being made from PVC.

[0014] According to the invention, the multilayer structure comprises a surface mass of between 1500 and 2500 g / m2, and a woven reinforcement bonded to the surface layer and to the backing layer by means of bonding layers in the form of hot-melt films (for example made of copolyamide CoPA in thermoplastic polyurethane TPU, or thermoplastic copolyester CoPES), or of a crosslinked polyurethane adhesive layer, and the backing layer made from PVC comprises: - a thickness between 150 pm and 600 pm; - less than 15 PCR of plasticizer.

[0015] The woven reinforcement improves the rigidity and dimensional stability of the multi-layer structure.

[0016] The amount of plasticizer is directly related to the amount of flame retardant required in the composition since plasticizers are flammable compounds. Thus limiting the amount of plasticizer to 15 PCR makes it possible to limit the amount of flame retardant, to limit the migration of plasticizers in the double-sided adhesives generally used to bond the multi-layer structure to a honeycomb floor of an aircraft for example, and consequently makes it possible to avoid degrading the adhesion properties of these adhesives over time.

[0017] The multilayer structure according to the invention thus has a backing layer, making it possible to obtain a floor covering whose manufacturing cost is relatively low, and which gives complete satisfaction in terms of the holding of the covering on its support, dimensional stability, and impact resistance. Given that the surface layer and the backing layer are both made from PVC, the recyclability of the multi-layer structure becomes possible.

[0018] Preferably, the backing layer made from PVC has a flexural strength, measured according to standard ISO 2493-2, of between 1 mN.m and 30 mN.m.

[0019] Preferably, the backing layer comprises 2% or less of flame retardant.

[0020] According to a particular embodiment, the surface layer comprises an upper layer, in particular a wear layer, and one or more intermediate layers of plasticized PVC.

[0021] For example, the upper layer is transparent, and a first intermediate layer directly disposed under the surface layer is for example in the form of a film printed with a decoration. In the latter case, a second intermediate layer is preferably disposed under the printed film to ensure sufficient opacity.

[0022] According to a particular embodiment, the woven reinforcement is impregnated with a thermoplastic or thermosetting polymer in an amount of between 1% and 10% by weight of the impregnated woven reinforcement so as not to degrade the recyclability. This allows the multilayer structure to have greater rigidity. The thermoplastic or thermosetting polymer may be chosen from the group comprising polyurethane resin, polyester resin, phenolic resin, epoxy resin, polysulfone, vinylester resin, epoxy-acrylic resin, and mixtures thereof.

[0023] Preferably and to improve the resistance to the phenomenon known to those skilled in the art under the English term "telegraphing", a layer of non-woven, advantageously comprising aramid fibers to confer fire-resistant properties, is bonded to a lower face of the backing layer by means of a bonding layer (6) in the form of a layer of crosslinked polyurethane PUR, or a layer of thermoplastic copolyester CoPES.

[0024] Advantageously, and to facilitate the installation of the multilayer structure according to the invention, the multilayer structure comprises on a lower face intended to be opposite the ground, that is to say directly on the lower face of the backing layer, or on the lower face of the non-woven layer, a layer of repositionable adhesive, that is to say which has a power of adhesion to the multilayer structure greater than the power of adhesion to the ground in order to be able to detach and reposition the multilayer structure. Brief description of the drawings

[0025] [Fig.l] illustrates in section a multi-layer structure according to a first embodiment of the invention, with a top layer, an intermediate layer, a woven reinforcement, and a backing layer.

[0026] [Fig.2] is a view similar to that of [Fig.l], with two intermediate layers.

[0027] [Fig.3] is a view similar to that of [Fig.2], with in addition a non-woven fabric on the lower face of the backing layer and a repositionable adhesive facing the ground. Detailed description of the invention

[0028] With reference to Figures 1 to 3, the invention relates to a multi-layer structure (1) for producing a floor covering, preferably for covering aircraft floors, for example honeycomb floors, without this being limiting.

[0029] The multilayer structure (1) according to the invention has a low manufacturing cost, while possessing optimal performance, that is to say in terms of the hold of the covering on its support, dimensional stability, impact resistance of the floor covering, recyclability.

[0030] For this purpose, the multilayer structure (1) according to the invention comprises at least one surface layer (2) made from PVC, bonded to a backing layer (3), also made from PVC.

[0031] According to the invention, the multilayer structure (1) comprises a surface mass of between 1500 and 2500 g / m2, preferably between 1700 and 2300 g / m2, and a woven reinforcement (5) bonded to the surface layer (2) and to the backing layer (3) by means of bonding layers (6) in the form of thermofusible or copolyester films, or layers of crosslinked polyurethane adhesive.

[0032] The backing layer (3) made from PVC comprises: - a thickness between 150 pm and 600 pm, preferably between 200 pm and 500 pm; - a quantity of plasticizer less than 15 PCR, or even less than 5 PCR, and for example free of plasticizer, “PCR” meaning part(s) percent of resin, the term “resin” relating to the PVC of the backing layer (3); - preferably a flexural strength, in particular the flexural strength B of PVC films measured according to standard ISO 2493-2 on a “Taber Stiffness” test bench from the company “Taber Industries”, model “TABER 150-E”, between 1 mN.m and 30 mN.m; - preferably an amount of flame retardant, for example antimony, less than or equal to 2% (by weight of the PVC backing layer).

[0033] A limited quantity of plasticizer makes it possible to limit the quantity of flame retardant agent, to limit the migration of plasticizers in the double-sided adhesives which are generally used to bond the multi-layer structure (1) to a floor, so as to avoid degrading the adhesion properties of said adhesives over time.

[0034] The bending strength is tested in the machine direction, the bending strength is determined as the average bending moment of 10 measured values, namely 5 bending movements in one direction and 5 bending movements in one direction opposite.

[0035] The surface layer (2) may comprise an upper layer (2a), in particular a wear layer, and one, see [Fig.l], or several, see [Fig.2], intermediate layers (4) made of plasticized PVC, for example with a quantity of plasticizer greater than 15 PCR.

[0036] The upper layer (2a) and the intermediate layers (4) are made integral for example by lamination, that is to say by hot lamination. For example, the upper layer (2a) has a thickness of between 0.35 mm and 0.55 mm, and the intermediate layer has a thickness of between 0.15 mm and 0.60 mm.

[0037] The upper layer (2a) is plasticized and optionally filled, and may optionally have a surface varnish well known to those skilled in the art, to ensure ease of maintenance.

[0038] According to a particular embodiment, the upper layer (2a) is transparent to light in the range visible to the human eye and the intermediate layer (4), directly arranged under the upper layer (2a), may be in the form, for example, of a film printed with a decoration on its face opposite the upper layer (2). In the latter case, it is preferable to arrange a second intermediate layer (4) which is positioned under the printed film to ensure sufficient opacity to the decoration and to avoid seeing the structure of the woven reinforcement (5).

[0039] The woven reinforcement (5) makes it possible to improve the rigidity and dimensional stability of the multilayer structure (1), and is for example in the form of a glass fabric.

[0040] Due to the lack of affinity of the woven reinforcement (5) with PVC, said woven reinforcement (5) is bonded to the surface layer (2) and to the backing layer (3) by means of bonding layers (6), for example in the form of hot-melt films (for example, made of copolyamide CoPA in thermoplastic polyurethane TPU, or in thermoplastic copolyester or CoPES), of layers of crosslinked polyurethane PUR, applied in the form of glue well known to those skilled in the art according to the English designation "hotmelt".

[0041] The reinforcement (5) is preferably woven in a plain weave, without this being limiting. A twill or satin woven weave could quite easily be considered.

[0042] The woven reinforcement (5) is preferably made from glass fibers, polyamide fibers or polyester fibers.

[0043] The glass fibers can have a count of between 22 Tex and 68 Tex. The polyester fibers can have a count of around 1100 decitex. The polyamide fibers can have a count of between 44 decitex and 78 decitex. The woven reinforcement (5) generally has a thickness of between 150 μm and 300 μm, preferably between 165 μm and 205 μm. The woven reinforcement (5) has a surface mass of between 150 and 300 g / m2, although this value depends on the nature of the fibers used.

[0044] When the woven reinforcement (5) is made from glass fiber, it has a number of warp threads of between 17 and 18 threads per cm and a number of weft threads of between 13.5 and 14 threads per cm.

[0045] Below 17 warp threads per cm or 13.5 weft threads per cm, the woven reinforcement (5) becomes porous, in particular with a count between 22 and 68 Tex.

[0046] Preferably the woven reinforcement (5) is impregnated with a thermoplastic or thermosetting polymer in an amount of between 1% and 10% by weight of the impregnated woven reinforcement so as not to degrade recyclability, to obtain greater rigidity and to limit or even eliminate the passage of glue likely to clog the lamination line during the process of assembling the layers.

[0047] The woven reinforcement (5) may comprise aramid yarns to provide fire-resistant properties.

[0048] The thermosetting or thermoplastic polymer may be chosen from the group comprising polyurethane resin, polyester resin, phenolic resin, epoxy resin, polysulfone, vinylester resin, epoxy-acrylic resin, and mixtures thereof.

[0049] Preferably and with reference to [Fig. 3], and to improve the resistance to the phenomena known to those skilled in the art under the English terms “telegraphing” and “buckling” or “waving”, a layer of non-woven textile (7) is bonded to a lower face of the backing layer (3) by means of a bonding layer (6) in the form of “hotmelt” glue, for example made of polyurethane PUR or copolyester “CoPES”.

[0050] The non-woven textile layer (7) advantageously has a surface mass of between 100 g / m2 and 350 g / m2, preferably between 150 g / m2 and 250 g / m2. A surface mass of at least 100 g / m2 makes it possible to improve the resistance to “telegraphing” and “buckling” (or “waving”).

[0051] A surface mass greater than 350 g / m2 can degrade the punching resistance of the multilayer structure (1) and increase its weight too much. A surface mass less than 100 g / m2 can, on the contrary, improve the punching resistance but degrade the telegraphing resistance properties. In fact, a surface mass between 150 g / m2 and 250 g / m2 makes it possible to obtain a good compromise between telegraphing resistance and punching resistance.

[0052] The thickness of the non-woven textile layer (7) is generally between 1.2 mm and 2.8 mm.

[0053] The nonwoven textile layer (7) may comprise self-extinguishing fibers so as to improve the fire resistance of the multi-layer structure (1) while improving the telegraphing resistance properties of the floor covering. Self-extinguishing fibers are generally fibers having a limit index oxygen limit (ILO) greater than 0.21 according to standard NF EN ISO 4589-2 / A1. In order to have a limiting oxygen index greater than 0.21, the non-woven textile layer (7) may in particular comprise fibers chosen from polyetherimide, polyester, polyacrylate, aramid, para-aramid, oxidized polyacrylonitrile, aromatic polyamide fibers and their mixtures. The quantity of each type of fiber can easily be adapted by a person skilled in the art to achieve a limiting oxygen index value greater than 0.21, in particular from the limiting oxygen index values ​​of each type of fiber used in the production of the non-woven textile layer (7).

[0054] Advantageously, the non-woven textile layer (7) has a limiting oxygen index greater than 0.28 according to standard NF EN ISO 4589-2 / A1. It has been found that better fire resistance results for the multi-layer structure (1) were obtained with a non-woven textile layer (7) having a limiting oxygen index greater than 0.28 according to standard NF EN ISO 4589-2 / A1. This limiting oxygen index value makes it possible in particular to obtain a floor covering according to the invention which can meet standard FAR 25.853 in terms of fire resistance without, however, excessively increasing the manufacturing cost of the floor covering.

[0055] Advantageously, the non-woven textile layer (7) has a limiting oxygen index greater than 0.32 according to standard NF EN ISO 4589-2 / A1. This limiting oxygen index value makes it possible in particular to obtain a floor covering which can meet standard FAR 25.853 in terms of fire resistance.

[0056] Advantageously, the non-woven textile layer (7) has a limiting oxygen index of less than 0.42, preferably less than 0.40 according to standard NF EN ISO 4589-2 / A1. Although limiting oxygen index values ​​greater than 0.40 are possible, the materials used to achieve them generally result in an additional cost for the floor covering. Preferably, the non-woven textile layer (7) has a limiting oxygen index of between 0.28 and 0.42 and more preferably of between 0.32 and 0.40 in order to obtain a good compromise between the manufacturing cost and the fire behavior of the floor covering.

[0057] Preferably, the non-woven textile layer (7) comprises fibers chosen from polyetherimide, polyester, polyacrylate, aramid, para-aramid, oxidized polyacrylonitrile, aromatic polyamide fibers, and mixtures thereof.

[0058] In order to improve the telegraphing resistance properties of the floor covering while maintaining good fire resistance properties and limiting manufacturing costs, the non-woven textile layer (7) may be made from a mixture of polyester fibers and polyetherimide fibers, a mixture of polyester fibers and aramid fibers, a mixture of polyacrylate fibers and aramid fibers, a mixture of polyester fibers and aramid fibers, or a mixture of fibers of oxidized polyacrylonitrile and para-aramid fibers.

[0059] Preferably and with reference to [Fig. 3], the multilayer structure (1) comprises on a lower face intended to be in contact with the ground, that is to say for example directly the lower face of the backing layer (3), or the lower face of the non-woven textile layer, a repositionable double-sided adhesive (8), that is to say which adheres more to the multilayer structure (1) than to the ground on which it is placed, thus facilitating installation.

[0060] The Applicant carried out tests on: - a reference product, in accordance with the prior art with a laminated backing layer; - a product A according to the invention; - a product B, not in accordance with the invention.

[0061] Products A and B have the same structure, except for the backing layer (3) which is different and whose characteristics are detailed in the table below.

[0062] Products A and B both have: - a top layer (2a) of 0.50 mm thick PVC, 640 g / m2; - an intermediate layer (4) made of PVC, 0.50 mm thick, 640 g / m2; - a bonding layer (6) in the form of a hot-melt film with a thickness of 0.045 mm, of 50 g / m2; - a woven frame (5) impregnated with a thickness of 0.15mm and 223g / m2; - a bonding layer (6) in the form of a hot-melt film with a thickness of 0.045 mm, of 50 g / m2; - a backing layer (3).

[0063] Table 1: Standards Requirements Reference: Prior Art -laminated backing Backing layer Product A Backing layer Product B Antimony oxide - - 0 0% 2% Plasticizer type - - 0 - DIDP / DPO Plasticizer rate - - - 0PCR 37 PCR (DIDP:21 / DPO: 16) PVC backing thickness (pm) - - - 220 pm 240 pm PF mass (theoretical) - 1720- 1750 1720 g / m2 1720 g / m2 1720 g / m2 FAR 25.853 (test with adhesive, without liner) AITM 2.0002B at 12 sec < 15 s OK 1s 1s Adhesion fabric - PVC -3J@23°C 180° peel at 50mm / min > 13 OK 38 N / 25 mm 26 N / 25mm Adhesion fabric - PVC -7J@70°C 180° peel at 50mm / min > 13 OK 33 N / 25 mm 21 N / 25mm Adhesion back / adh. 3M950 - 3J@23°C ISO 4578 > REF 15 N / 25mm 19 N / 25 mm 47 N / 25mm Backing adhesion / adh. 3M950 - 7J@70°C ISO 4578 >20 37 N / 25mm 30 N / 25 mm 14 N / 25mm

[0064] In this table we note that the tested product B, not covered by the invention, namely with a plasticized and flame-retardant PVC backing, in particular comprising 37PCR of plasticizers, is not suitable because it does not allow the adhesion test according to the ISO4578 standard to be satisfied.

[0065] In particular, the backing layer glued to a support with a commercially available acrylic adhesive sold by the company 3M under the registered trademark 3M® reference 950, does not satisfy the adhesion test of the ISO 45 78 standard which provides that the layer must detach with a force greater than 20 N / 25 mm, whereas Product B detaches with a force of 14 N / 25 mm.

[0066] The reference product, namely the product with laminated backing, as well as product A according to the invention with rigid PVC backing free of plasticizer, both satisfy the adhesion tests to the support carried out according to standard ISO 4578, with the same adhesive (3M950).

[0067] Product A also passes the adhesion tests between the PVC backing layer (3) and the woven reinforcement (5), as well as the fire tests according to FAR 25.853.

[0068] It is clear from the above that the multilayer structure according to the invention has a backing layer whose manufacturing cost is low compared to that of laminated layers, which multi-touch structure gives complete satisfaction in terms of the holding of the covering on its support, dimensional stability, impact resistance of the floor covering, while presenting improved recyclability.

Claims

Claims

1. Multi-layer structure (1) for producing a floor covering, comprising at least one surface layer (2) bonded to a backing layer (3), the surface layer (2) and the backing layer (3) being made from PVC; characterized in that the multi-layer structure (1) comprises a surface mass of between 1500 and 2500 g / m2, and a woven reinforcement (5) bonded to the surface layer (2) and to the backing layer (3) by means of bonding layers (6) in the form of hot-melt or copolyester films, or layers of crosslinked polyurethane adhesive; and in that the backing layer (3) made from PVC comprises: - a thickness of between 150 pm and 600 pm; - less than 15 PCR of plasticizer.

2. Multilayer structure (1) according to claim 1, characterized in that the backing layer (3) made from PVC comprises a flexural strength measured according to standard ISO 2493-2 of between 1 mN.m and 30 mN.m.

3. Multilayer structure (1) according to one of the preceding claims, characterized in that the backing layer (3) comprises 2% or less of flame retardant agents.

4. Multilayer structure (1) according to one of the preceding claims, characterized in that the surface layer (2) comprises an upper layer (2a) and one or more intermediate layers (4) made of plasticized PVC.

5. Multilayer structure (1) according to claim 4, characterized in that the upper layer (2a) is transparent and the intermediate layer (4) which is directly arranged under the upper layer (2) is a film printed with a decoration.

6. Multilayer structure (1) according to one of the preceding claims, characterized in that the woven reinforcement (5) is impregnated with a thermoplastic or thermosetting polymer in an amount of between 1% and 10% by weight of the impregnated woven reinforcement.

7. Multi-layer structure (1) according to one of the preceding claims, characterized in that a non-woven textile layer (7) is bonded to a lower face of the backing layer (3) by means of a bonding layer (6) in the form of crosslinked polyurethane or a thermoplastic copolyester layer.

8. Multilayer structure (1) according to claim 7, characterized in that the non-woven textile layer (7) comprises aramid fibers.

9. Multilayer structure (1) according to one of the preceding claims, characterized in that it comprises on a lower face intended to be facing the ground, a layer of repositionable double-sided adhesive (8).

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