Multilayer structure for creating a floor covering

Abstract

The invention relates to a multilayer structure (1) for creating a loose-lay floor covering. The multilayer structure (1) is without coupling means and comprises successively: - a top wear layer (2) of PVC comprising 20 to 50 PCR of plasticizer, and having a thickness of between 0.3 and 2 mm, preferably between 0.5 and 1 mm; - a first reinforcing layer (3); - a backing layer (4) of compact PVC comprising 40 to 60 PCR of plasticizer, and a load factor greater than 130 PCR; notable in that the backing layer (4) has a thickness of between 0.2 and 1 mm, and in that the multilayer structure (1) comprises an underlayer (5) of PVC comprising 30 to 50 PCR of plasticizer and a load factor less than 5% by weight of the underlayer (5) and having a thickness of between 0.05 and 0.5 mm, and in that the multilayer structure (1) has a total thickness of less than 3.5 mm. Figure for the abstract: Fig. 1

Description

Description Title of the invention: Multilayer structure for the production of a flooring Technical field

[0001] — The present invention relates to a multi-layer structure, devoid of means coupling and presented in slabs, blades, or rolls, for the production of a re- loose-fitting floor garment. Artterior

[0002] Known from the state of the art is a multilayer structure devoid of means coupling, presented in slabs, blades, or rolls, for the production of a re- loose-fitting floor covering.

[0003] This multi-layer structure successively comprises, that is to say from the top towards the ground: - a top wear layer made of plasticized PVC, and having a thickness of between between 0.3 and 2 mm: - a layer of compact, i.e. non-foamed, plasticized PVC backing obtained, not by coating, but rather by calendering, pressing or extrusion, the layer backing is laminated and with a charge rate greater than 130 PCR, or even greater than 150PCR.

[0004] — In order to facilitate installation and improve the dimensional stability of this type of re- floor garment, it is known that the backing layer includes a reinforcement of reinforcement, such as a glass veil coated with a gelled PVC plastisol on both sides and placed in contact with the wear layer.

[0005] — To facilitate freestanding, the structure must be balanced and, to do this, it is known to add fillers in the PVC backing layer or to increase its thickness to have a thickness greater than | mm.

[0006] Furthermore, for surfaces greater than 30 m2, or even greater than 50 m2, the installation This type of coating still requires the use of a tackifier for ensure the maintenance, or even double-sided adhesive on the periphery of the surface to be coated.

[0007] — The resulting disadvantage is that the total thickness of the structure becomes too significant, especially between 4 and 6 mm, which results in too much weight, the order of 5 to 7 kg / m°, and therefore logistical difficulties and problems environmental impact.

[0008] — Document EP3505342 describes the implementation of a second layer reinforced with a second reinforcement frame, which makes it possible to stiffen the structure and to form a so-called “bimetallic strip” effect, contributing to the weighting effect of the slab, which makes it easier to install. However, the disadvantages of the heavy weight of the structure are still present. Another disadvantage of the prior art is encountered when the upper wear layer is transparent, with 20 to 50 PCR of plasticizer, and a zero filler rate, or even less than 5% by weight of the upper layer. In this situation, the low amount of charge causes, during the manufacture of the structure, a shrinkage of the wear layer which generates the phenomenon well known to those skilled in the art under the English term of "curving", in which the periphery of the multi-layer structure rises, which creates an imbalance. Statement of the invention One of the aims of the invention is therefore to propose a multi-layer structure for the production of a floor covering, which is balanced and suitable for loose installation without coupling means, with satisfactory rigidity to withstand the passage of heavy loads, while having a mass of less than 5 kg / m? to facilitate logistics and reduce the environmental impact. For this purpose, a multi-layer structure was developed without coupling means and comprising successively, that is to say from the top to the ground: - a PVC wear top layer comprising 20 to 50 PCR of plasticizer (PCR means one hundred parts of resin), and having a thickness of between 0.3 and 2 mm, preferably between 0.5 and 1 mm; - a first reinforcement frame; - a backing layer of compact PVC, i.e. which is not foamed, preferably calendered, pressed or extruded, and comprising between 40 and 60 PCR, preferably between 50 and 55 PCR of plasticizer and a filler rate greater than 130 PCR, or even 150 PCR, more preferably greater than 200 PCR, without exceeding 250 PCR. According to the invention, the backing layer has a thickness of between 0.2 and | mm, and the multilayer structure comprises a PVC underlayer, i.e. the last layer of the structure intended in particular to be in contact with the ground, comprising 20 to 50 PCR, preferably 30 to 50 PCR of plasticizer and a filler rate of zero, or even less than 5% by weight of the underlayer. Furthermore, the underlay has a thickness of between 0.05 and 0.5 mm, for a multi-layer structure with a total thickness of less than 3.5 mm, and for example less than 3 mm when presented in a roll. The presence of the underlay according to the invention makes it possible to balance the structure, without requiring an increase in the thickness of the loaded PVC backing layer. In practice, the low charge rate in the upper wear layer of plasticized PVC causes the phenomenon of "curving" or incurvation tending to unbalance the multilayer structure. However, the presence of the underlayer according to the invention, which is also plasticized and which also comprises a low charge rate, makes it possible to generate the reverse curving phenomenon well known to those skilled in the art under the English term "doming" in which the edges of the structure lower (or the center rises), creating a reverse imbalance which therefore compensates and rebalances the structure. Given the low charge rate in the underlayer, another advantage is that it has a lower surface mass than the backing layer, which is charged and therefore heavier. In other words, the invention makes it possible to rebalance the structure, with a lower weight, compared to the known solution of increasing the thickness of the backing layer. The high level of plasticizer in the backing layer increases the flexibility of the structure. The presence of the underlayer according to the invention therefore also makes it possible to stiffen the multilayer structure with a minimum of material, in order to facilitate free installation, reduce the weight compared to the prior art, and consequently reduce the environmental impact. In a particular embodiment, the upper wear layer is transparent and comprises 30 to 50 PCR of plasticizer, with a loading rate of zero, or even less than 5% by weight of the upper layer, and the multi-layer structure comprises a decor layer positioned under the upper wear layer. The decorative layer may, for example, be in the form of a layer of ink printed on a lower face of the wear layer, or on an upper face coated with the first reinforcement, or on an upper face of a decorative film positioned under the wear layer. In this configuration, the low load rate in the upper wear layer of plasticized PVC causes the phenomenon of "curving" or incurvation tending to unbalance the multi-layer structure, compensated by the underlayer. According to another embodiment, the wear layer may be in the form of a layer of pressed granules, so that the wear layer itself forms the decoration. The granules may be of any desired color, as is well known in the prior art. The layer of pressed granules is obtained from plasticized and loaded PVC. Generally, the loading rate of the pressed granules is much lower than 130 PCR, preferably lower than 100 PCR or even 80 PCR so as to have good scratch resistance. The layer of pressed granules thus tends to cause a phenomenon of "curving" or incurvation tending to unbalance the multi- structure layer, which is compensated by the underlayer. Advantageously, the multi-layer structure comprises a second reinforcing reinforcement, embedded in the surface of the backing layer and bonded to a lower face of the first reinforcing reinforcement by a bonding layer. This improves the rigidity of the multi-layer structure, and in particular allows it to meet the resistance test for a chair with casters when laid loose, or even semi-loose, with the use of double-sided adhesive on the periphery and edges of the strips in the case of a roll. The bonding layer is for example a plastisol layer, for example a gelled PVC plastisol. According to another embodiment, the bonding layer can also be made by a lower layer of plastisol impregnation, such as a gelled PVC plastisol, and a glass veil which comprises the first reinforcing frame. In this situation, the decorative layer can be printed on an upper layer of plastisol, such as a PVC plastisol, coated on the glass veil and then gelled. According to particular embodiments, the first and / or the second reinforcement frame is in the form of a glass veil, a glass grid, or a glass grid and glass veil complex, in particular to satisfy the tests of resistance to the passage of heavy loads and punching. Preferably, and to ensure a good compromise between the total thickness of the multi-layer structure and its weight, while having a balanced structure, a ratio between the thickness of the upper wear layer and the thickness of the assembly comprising the backing layer and the underlayer, is between 0.65 and 1. In order to further reduce, or even avoid, the wave / swell phenomenon which is generated in front of the wheels of a heavy load, i.e. of the order of 200 kg or more, circulating on the multi-layer structure in free laying on a ground, the underlay according to the invention is preferably produced by coating, calendering or extrusion, because these techniques make it possible to obtain a smoother contact surface with the ground than when the underlay is pressed and then sanded. According to another characteristic, the multilayer structure according to the invention preferably has a modulus of elongation at 1% of between 7 and 9 daN / cm. Brief description of the drawings Other characteristics and advantages of the invention will emerge clearly from the description given below, for information purposes only and in no way limiting, with reference to the appended figures in which: [Fig.1] is a schematic cross-sectional representation of one embodiment of the multi-layer structure of the invention. [Fig.2] is a schematic cross-sectional representation of another embodiment of the multi-layer structure of the invention incorporating a printed decorative layer. [Fig.3] is a schematic cross-sectional representation similar to that of [Fig.2], the decorative layer being printed on a polymer film. [Fig.4] is a schematic representation, in section similar to that of [Fig.2], the decorative layer being printed on a glass veil coated on both sides with a PVC plastisol. [Fig.5] is a schematic representation, in section similar to that of [Fig.1], the structure integrating a second reinforcement frame embedded in the surface of the backing layer and linked to the first frame by a bonding layer. [Fig.6] is a schematic representation, in section similar to that of [Fig.5], the multi-layer structure integrating a decorative layer, for example conforming to that of [Fig.4]. Detailed description of the invention The invention relates to a multi-layer structure for producing a loose-lay floor covering, without coupling means between two adjacent structures, which is balanced with a low weight, i.e. less than 5 kg / m?, while having a total thickness of less than 3.5 mm. The multilayer structure according to the invention can have any shape, in particular in panel, slab or blade, and can be wound on itself or on a mandrel to be presented in a roll. When presented in a roll, the multi-layer structure has a flexibility that allows it to comply with ISO 24344:2008. In this standard, flexibility is defined as the ability of a covering or a layer of a floor covering to be rolled around a 20 mm mandrel, without cracks or crazing forming. Thus, the multi-layer structure according to the invention subjected to this test would not exhibit breaks, cracks, crazing and other permanent defects. With reference to [Fig. 1], the multi-layer structure (1) comprises successively, from the top towards the ground, an upper wear layer (2) made of plasticized PVC, a first reinforcing frame (3), a compact backing layer (4) made of plasticized and loaded PVC, and an underlayer (5) made of unloaded plasticized PVC intended to form the last layer of the structure, in particular with a view to being in contact with the ground. The upper wear layer (2) provides slip control, wear resistance and ease of cleaning. It includes 20 to 50 PCR of plasticizer and has a thickness of between 0.3 and 2 mm, preferably between 0.5 and 1 mm. The upper wear layer (2) can be obtained by extrusion, calendering, pressing, or by coating and then gelling a plastisol. The upper layer wear layer (2) may be coated with a varnish without departing from the scope of the invention, such as a varnish based on polyurethane or urethane acrylate. The upper wear layer (2) may be varnished and / or grained in order to improve resistance to staining and scratching. The upper wear layer (2) can also serve as a decoration, particularly if it is obtained from a tinted plastisol or by pressing tinted granules. Preferably, and with reference to [Fig. 2], the upper wear layer (2) is transparent or translucent so that a decorative layer (6) is visible through the upper wear layer (2). In this configuration, the upper wear layer (2) comprises 30 to 50 PCR of plasticizer, and a zero filler rate, or even less than 5% by weight of the upper wear layer (2), and the decorative layer (6) can be printed on a lower face of the upper wear layer (2), or on an upper face coated with the reinforcement, or on a polymer film (7) such as a PVC film, see [Fig.3], printed by any known technique and positioned under the upper wear layer (2). The first reinforcement frame (3) can be a glass grid, a glass fiber veil. In order to combine the advantages of the various existing solutions, the frame includes a glass veil, which is complexed with the glass grid by means of a binder, preferably by lamination. In order to bond the glass veil with the glass grid without complicating the manufacturing process or unduly weighing down the structure, the binder comprises an acrylic glue, or ethylene-vinyl acetate ("EVA"), or plastisol such as a PVC plastisol. Preferably the binder is arranged in a thin layer, at a density of between 5 and 35 g / m2, or preferably between 10 g / m? to 30 g / m?. For example, the glass veil comprises glass fibres of approximately 10 um in diameter and 10 mm in length, distributed randomly and linked together by a modified polyvinyl alcohol. Glass veil generally has a surface mass of between 30 g / m² and 100 g / m². The tensile strength of a reinforcing veil is generally chosen to be between 100 N / 50 mm and 400 N / 50 mm in the longitudinal and transverse directions, measured according to the ISO 1924 / 2 method. The threads of a glass grid according to the invention are for example obtained from glass fibers, and are preferably spaced from each other by between 1 mm and 5 mm, preferably by between 2 mm and 4 mm, depending on the longitudinal and transverse dimensions, and have a linear mass of between 20 g / m and 110 g / m, advantageously between 35 g / m and 70 g / m. A glass grid generally has a thickness of between 0.1 mm and 1 mm and a surface mass of between 30 g / m2 and 150 g / m2, preferably between 45 g / m2 and 110 g / m2. The resistance to traction of a reinforcement grid according to the invention is advantageously between 400 N / 50mm and 1000 N / 50mm in the longitudinal and transverse directions. The first reinforcing frame (3) makes it possible to improve the dimensional stability of the multi-layer structure (1) as well as the resistance to punching. The multi-layer structure according to the invention can claim class U4P3 according to the UPEC standard. The first reinforcing frame (3) may be bonded to the decorative layer (6) and to the backing layer (4) by any means, in particular by thermolamination, cold bonding, hot bonding, extrusion of the layer(s) onto the first reinforcing frame (3), by powdering with hot melt glue or by using a double-sided adhesive. If the first reinforcing frame (3) is bonded by thermolamination, this directly penetrates the thickness of the backing layer (4) and the decorative layer (6) which then impregnate the first reinforcing frame (3). According to a particular embodiment, see [Fig.4], the first reinforcing frame (3) is a glass veil impregnated on its lower face with a bonding layer in the form of a gelled plastisol (8), such as a PVC plastisol, and on its upper face with a plastisol, such as a PVC plastisol, gelled and printed with a decorative layer (6). The backing layer (4) is made of compact plasticized polyvinyl chloride, i.e. it is not foamed. The backing layer (4) has a thickness of between 0.2 and | mm, and is calendered, pressed, or extruded. Generally, a calendered backing layer (4) is preferred because it is easier to integrate recycled material into its composition with this manufacturing technique, without degrading the decoration or the appearance of the multilayer structure (1). The backing layer (4) comprises between 40 and 60 PCR, preferably between 50 and 55 PCR of plasticizer and a filler rate greater than 130 PCR, or even 150 PCR, or even greater than 200 PCR and up to 250 PCR. With reference to [Fig.5], the multilayer structure (1) preferably comprises a second reinforcing frame (9) to increase rigidity and improve dimensional stability and in the form of a glass veil, a glass grid, or a glass grid and glass veil complex. The second reinforcing frame (9) is embedded in the surface of the backing layer (4) so ​​as to limit the deformation of the decorative layer (6), and is bonded to a lower face of the first reinforcing frame (3) by a bonding layer (10), in particular in the form of a plastisol, preferably a PVC plastisol with a thickness of between 0.1 and 0.3 mm. According to the invention, the PVC underlayer (5) comprises 20 to 50 PCR, preferably 30 to 50 PCR of plasticizer and a zero filler rate, or even less than 5% by weight of the underlayer (5). The underlay has a thickness between 0.05 and 0.5 mm and is preferably obtained by coating or is hot rolled after being obtained by calendering or extrusion. The underlayer (5) can be related to the upper wear layer (2), in terms of composition and properties, and therefore makes it possible to balance the structure by counterbalancing the curvature phenomenon generated by the upper wear layer (2), with a low weight compared to the backing layer (4) (at equivalent thickness). Preferably, the upper wear layer (2) and the underlayer (5) are obtained from plasticized PVC and have the same plasticizer content. The calendered, loaded and plasticized backing layer (4) increases the mass and flexibility of the structure, the underlayer (5) then stiffens the structure to facilitate installation. The plasticizers used in the multilayer structure (1) are of all well-known types, such as Diisononyl Phthalate (DINP), Diisodecyl Phthalate (DIDP), 2-Ethylhexyl Diphenyl Phosphate (DPO), Dioctyl Terephthalate (DOTP), 1,32-cyclohexane dicarboxylic acid diisononyl ester (DINCH), plasticizers of the benzoate family, plasticizers of the adipate family, plasticizers marketed under the PEVALEN® brand by the company Perstorp, epoxidized soybean oil (HSE), octyl epoxy stearate (ESO), totally or partially bio-sourced plasticizers such as, for example, the plasticizers of the polysorb® exelD 37 range marketed by the company Roquette Pharma, plasticizers from the Citrofol® range marketed by Jungbunzlauer International AG, or plasticizers from the Soft-n-safe® range marketed by Danisco. Liquid plasticizers can be used alone or in a mixture. The fillers used in each of the layers of the structure may be calcium carbonate, clay, silica, kaolin, or talc. This is preferably a powdered material to prevent the filler from degrading during mixing of the PVC masterbatch intended to form the layers, but fibers may be considered. The fillers can be used alone or in a mixture. To ensure a good compromise between the total thickness of the multi-layer structure (1) and its weight, while having a balanced structure, a ratio between the thickness of the upper wear layer (2) and the thickness of the assembly comprising the backing layer (4) and the underlayer (5), is between 0.65 and 1, for example 0.97 or 0.72. Comparative tests were carried out by the Applicant on the following products: Example 1 according to the invention having a total thickness of 2.39 mm for a surface mass of 3.234 kg / m?, and comprising: - a top layer (2) of transparent wear in plasticized PVC, not loaded 0.68 mm thick; - a veil of glass fibers (3) impregnated with a PVC plastisol (8) and 0.58 mm thick, coated on an upper face with a printed PVC plastisol (6) 0.18 mm thick - a bonding layer (10) made of PVC plastisol with a thickness of 0.25 mm; - a compact backing layer (4) made of plasticized and loaded PVC, reinforced by a glass grid, with a thickness of 0.60 mm; - an underlayer (5) in plasticized and unfilled PVC, 0.1 mm thick. Example IB not in accordance with the invention having a total thickness of 2.29 mm for a surface mass of 3.114 kg / m?, and comprising: - a transparent top wear layer made of plasticized PVC, unfilled, 0.68 mm thick; - a veil of glass fibers impregnated with a PVC plastisol and 0.58 mm thick, coated on one upper face with a printed PVC plastisol 0.18 mm thick - a 0.25 mm thick PVC plastisol bonding layer; - a compact backing layer made of plasticized and loaded PVC, reinforced by a glass grid, 0.60 mm thick. Example 2 according to the invention having a total thickness of 2.42 mm for a surface mass of 3.394 kg / m?, and comprising: - a top layer (2) of transparent wear in plasticized PVC, unfilled, 0.65 mm thick; - a veil of glass fibers (3) impregnated with a PVC plastisol (8) and 0.56 mm thick, coated on an upper face with a printed Plastisol (6) 0.16 mm thick: - a bonding layer (10) made of PVC plastisol with a thickness of 0.15 mm; - a compact backing layer (4) made of plasticized and loaded PVC, reinforced by a glass grid, 0.80 mm thick; - an underlayer (5) in plasticized and unfilled PVC, 0.1 mm thick. Example 2B not in accordance with the invention having a total thickness of 2.32 mm for a surface mass of 3.262 kg / m?, and comprising: - a transparent top wear layer made of plasticized PVC, unfilled, 0.65 mm thick; - a veil of glass fibers impregnated with a PVC plastisol and 0.56 mm thick, coated on one upper face with a printed Plastisol 0.16 mm thick; - a bonding layer (10) made of PVC plastisol with a thickness of 0.15 mm; - a compact backing layer (4) made of plasticized and loaded PVC, reinforced by a glass grid, 0.80 mm thick. The results are compiled in the table below. [Tables 1] Punching | Curvature (mm) (mm) 2h30 | 24h Di- |Module |Telegraphing mensional stability |1% after chair at (%) (daN / em) |casters s |sL ST Ex. 0.7 Ex2 002 |-0.1 Ex.2B — - |gnsoec Imois |SL |sT 23°C 07 law [003 |-0.03 |s8 = 19 |-001 |-004 |8.1 [01 [01 [002 |-005 |s3 “Jos Jos [002 |-003 |s.1 With in the “telegraphing” column: . = not visible 2 = barely visible 3 = visible 4 = very visible The phenomenon known by the English term "telegraphing", being that during which irregularities in the surface of the reinforcement or the ground are transferred to the surface of the covering, and result in unevenness in its appearance or flatness It can be seen from the table above that examples 1 and 2 according to the invention give satisfactory results in terms of resistance to punching since the values ​​obtained tend towards 0 mm. It is also noted that examples 1 and 2 according to the invention give satisfactory results in terms of balancing, i.e. reduction of the curvature phenomenon since at 1 month at 23°C, the values ​​obtained tend towards 00 mm, while in examples 1B and 2B not in accordance with the invention, the values ​​are close to 1 mm, or even 2 mm. Resistance to the curling phenomenon at 1 month at 23°C is improved by increasing the thickness of the backing layer and therefore the total weight of the multi-layer structure, see comparison between example 1B and 2B. Thus, at equivalent weight, see comparison between example 1 according to the invention and non-compliant example 2B, the resistance to the curving phenomenon at 1 month at 23°C is improved in example 1 according to the invention. It is also noted that examples 1 and 2 according to the invention give satisfactory results in terms of reduction of the “telegraphing” phenomenon, since after passing 25,000 cycles of the wheeled chair according to the standardized test (NF EN 425, July 2002), the scores obtained are between | and 2, while in examples 1B and 2B not in accordance with the invention, the scores obtained are greater than 2, in particular 4. Furthermore, the Applicant also noted that when a heavy load of around 200 kg (100 kg hospital bed with a weight of 100 kg) passes over the structure, this does not generate any waves in front of the wheels for examples | and 2 according to the invention, and example 2B, while a wave of 8.9 mm is present for example 1B. It can be seen that the modulus at 1% elongation increases at constant thickness, see comparison between example 1 and example 2B which shows an increase in the rigidity of the product, thus increasing its resistance to traffic when laid loose. The elongation modulus at 1% between 7 and 9 daN / cm allows for a good hand. The above values ​​are values ​​measured according to the following standards: Total thickness: NF EN ISO 24346 April 2012 Layer thicknesses: NF EN ISO 24340 April 2012 Weight / Surface mass: ISO 23997 December 2007 Modulus at 1% elongation: QB 30 - M1-Ueatc July 2015 Curving 6 hours at 80°C: NF EN ISO 23999 August 2018 Curving 72 hours at 80°C: NF EN ISO 23999 August 2018 Curvature monitoring | month at 23°: NF EN ISO 23999 August 2018 Dimensional stability 6h at 80°C: NF EN ISO 23999 August 2018 Residual static punching (Building): ISO 24343-1 June 2007 It is clear from the above that the invention provides a multi-layer structure (1) for producing a floor covering, which is balanced and suitable for loose laying without coupling means, with satisfactory rigidity to withstand the passage of heavy loads, while having a mass of less than 5 kg / m? to facilitate logistics and reduce environmental impact.

Claims

Claims

1. Multi-layer structure (1) for producing a floor covering cn free-standing, the multi-layer structure (1) is devoid of means coupling and successively includes: - a top layer (2) of PVC wear comprising 20 to 50 PCR of plasticizer), and having a thickness between 0.3 and 2 mm, of preferably between 0.5 and Imm; - a first reinforcement frame (3); - a backing layer (4) in compact PVC and comprising 40 to 60 PCR of plasticizer, and a charge rate greater than 130, or even greater than 150 PCR, or even more than 200 PCR and up to 250 PCR; characterized in that the backing layer (4) has a thickness of between 0.2 and 1 mm, and in that the multilayer structure (1) comprises a PVC underlayer (5) comprising 20 to 50 PCR of plasticizer and a filler rate of less than 5% by weight of the underlayer (5) and having a thickness of between 0.05 and 0.5 mm, and in that the structure Multilayer structure (1) according to claim 1, characterized in that that the upper wear layer (2) is transparent, includes 30 to 50 PCR of plasticizer, and a loading rate of less than 5% by weight of the upper layer (2), and in that the multilayer structure (1) includes a decorative layer (6) positioned under the upper layer (2) wear.

3. Multilayer structure (1) according to claim 2, characterized in that that the decorative layer (6) is a layer of ink printed on one side lower part of the upper wear layer (2), or on a su- upper coated with the first reinforcement frame (3), or on one face upper part of a decorative film positioned under the upper wear layer (2).

4. Multilayer structure (1) according to claim 1, characterized in that that the upper wear layer (2) is a layer of pressed granules.

5. Multilayer structure (1) according to one of the preceding claims, characterized in that it comprises a second reinforcing frame (9), embedded in the surface of the backing layer (4) and bonded to an in- lower than the first reinforcement frame (3) by a bonding layer {10).

6. Multilayer structure (1) according to claim 5, characterized in that that the bonding layer (10) is a plastisol layer, such as a gelled PVC plastisol.

7. Multilayer structure (1) according to one of the preceding claims, characterized in that the first and / or second frame of reinforcement (9) is a glass veil, a glass grid, or a complex glass grid and glass veil.

8. Multilayer structure (1) according to one of the preceding claims, characterized in that a ratio between the thickness of the upper layer (2) wear and thickness of the assembly including the backing layer (4) and the underlayer (5), is between 0.65 and 1.

9. Multilayer structure (1) according to one of the preceding claims, characterized in that it comprises an elongation modulus of 1% between 7 and 9 daN / cm.