Multi-layer structure for cladding a heated floor or heated wall

Description

TECHNICAL FIELD

[0001] The present invention relates to a multi-layer heating structure, in particular for producing a heated floor or wall covering. The multi-layer structure according to the invention may be in the form of a rolled strip or in the form of a panel, a slab, a blade, or the like.

[0002] The invention finds an advantageous application in the production of a heated floor or wall covering, that is to say incorporating elements allowing the heating of the room or premises in which it is installed, using electrical energy.

[0003] More generally, the invention finds an advantageous application in the production of a flexible, heterogeneous multi-layer structure presented in a roll, allowing the heating of a room or a building by Joule effect. PRIOR ART

[0004] A multi-layer structure for producing a floor covering is known from the prior art. This multi-layer structure generally comprises a top decorative and surface layer whose main functions are wear resistance, ease of cleaning and decorative appearance, linked to a backing underlay intended to be glued to the floor or similar.

[0005] These multi-layer structures are commonly installed on a concrete slab, screed, or leveling compound in which the heating functions are embedded. This is particularly the case for underfloor heating systems using water circulation. The disadvantage of these systems integrated into the floor is that they are difficult to repair because they are inaccessible by definition, and they are cumbersome to install in the case of renovations to existing homes or premises.

[0006] Multi-layer structures for floor coverings can also be used in combination with an attached heating underlay, incorporating a heating function using conductive electrodes or water circulation. During installation, the heating underlay is laid on the substrate, such as a screed or leveling compound. The floor covering is then laid on the heating underlay in a loose-laying manner, or in a glued-down manner using acrylic adhesive, or even in an adhesive-coated manner.

[0007] The disadvantage of these added heating underlays is that they require multiple installation operations for the same surface. These operations are all the more complex as they require cutting and adjustments for both the heating underlay and the floor covering.

[0008] On the other hand, depending on the number and thickness of the layers in the floor covering, the efficiency of the heating function can be greatly reduced. The layers of the floor covering can thus have a barrier effect and limit the transmission of heat from the heating underlay to the room to be heated.

[0009] Another disadvantage of these added heating underlays is that they mostly incorporate a network of resistive electrodes or water circulation channels distributed unevenly over the surface to be heated, thus leading to an uneven distribution of heat dissipation in the room. In addition, they have significant thicknesses, particularly greater than 1 mm, making their integration impossible among the layers of a multi-layer structure for the creation of a floor covering retaining adequate flexibility properties.

[0010] Multilayer structures are also known for producing underfloor heating, comprising a heating layer interposed between the surface layer and the backing sub-layer of said multilayer structures, said heating layer being produced from a network of electrodes. However, these multilayer structures have the same problems of non-uniform distribution of the heating of the room, the network of electrodes having to be very branched to heat the entire surface. The network of electrodes thus generally comprises a conductor making numerous loops under the surface to be heated. As a result, the design of these multilayer structures makes it difficult or even impossible to pierce the heating layer without risking cutting an electrode and thus dissociating part of the network of electrodes from the electrical current supply.Drilling operations may be necessary before installation to bypass an obstacle on the support such as a pipe, or after installation to allow the passage of a sheath or cable through the floor covering. These multi-layer structures thus complicate the cutting and drilling of the covering during or after the installation operation. In addition, the production of the electrode network is complex and expensive in conductive material, this being mainly made of copper or aluminum. Among the prior art documents, documents US3627981A and FR2124610A1 describe multi-layer heating structures, but these are clearly unsuitable for use as floor coverings with resistance to traffic or perforation. Document FR1535059A2 describes a heating structure in the form of a blanket, but no application as a floor covering is described. STATEMENT OF THE INVENTION

[0011] One of the aims of the invention is therefore to overcome the aforementioned drawbacks by proposing a multi-layer structure resistant to traffic and punching for the production of a heated floor or wall covering or similar, and which is easy to install, repair and renovate, which retains adequate flexibility properties to facilitate its presentation, for example in a roll, and its installation, which has good heating efficiency and the heating of which is distributed evenly over said covering, which is inexpensive to implement, and which is easy to drill and cut. The invention is set out in the set of claims attached to this description.

[0012] Another objective of the invention is to provide such a multi-layer structure which has mechanical properties making it possible to maintain a laying operation comparable to conventional operations for laying wound strips, panels, slabs, blades, or the like. This is particularly in order to use the multi-layer structure for the renovation of homes or premises, without carrying out heavy operations or generating rubble.

[0013] For this purpose, a multi-layer structure is proposed for producing a heated floor or wall covering or the like, in accordance with that of the state of the art in that it comprises an upper decorative layer consisting of at least one surface layer of plastic material, said decorative layer being bonded to a heating layer, said heating layer being bonded to a lower sub-layer intended to be laid on the floor or a wall or the like.

[0014] According to the invention, the surface layer is made of polyvinyl chloride and has a thickness of between 0.2 and 1 mm, the underlayer is obtained by coating, pressing, extrusion or calendering and from PVC, and the heating layer comprises a conductive strip made of a non-woven textile comprising conductive particles distributed homogeneously on the surface and / or in the thickness of the non-woven textile, said conductive strip supporting at least three conductive electrodes, said electrodes being spaced from one another and electrically powered so as to define a discontinuous heating surface.

[0015] In a general but non-limiting manner, the electrodes extend substantially in a longitudinal direction and are arranged parallel to one another.

[0016] According to one embodiment, the electrodes are spaced apart from each other and arranged parallel to each other so as to obtain a central electrode arranged between two lateral electrodes. For example, the central electrode is substantially arranged in the center of the conductive strip and equidistant from two lateral electrodes.

[0017] To obtain a heating surface, the electrodes are configured so as to present an electrical potential difference and obtain an electric current flow between at least two electrodes. For example, an electric potential is applied to the central electrode and at least one different electric potential is applied to each of the lateral electrodes, so as to obtain a current flow between the central electrode and each of the two lateral electrodes. This flow can in particular be obtained with a direct current or an alternating current.

[0018] The multi-layer structure thus obtained allows in particular a homogeneous distribution of the heating when at least part of the conductive strip of said heating layer is crossed by an electric current. By applying an electric voltage, obtained by a potential difference, between two conductive electrodes, the resistance of the conductive strip arranged between these two electrodes produces a release of heat by Joule effect distributed over the entire heating surface between the electrodes. The heat is then transmitted to the different layers of the multi-layer support, in particular the decorative layer, then to the room in which the structure is arranged, thus allowing the room to be heated.

[0019] The conductive strip comprises conductive particles distributed homogeneously over the surface and / or in the thickness of said conductive strip, it can thus be partially cut or perforated without risking electrically insulating one part of the conductive strip from another. The heating surface obtained is considered to be discontinuous insofar as no heating is obtained over the width of the conductive strip supporting the conductive electrodes. The electrodes are thus advantageously chosen to be very narrow, more advantageously in the form of conductive ribbons. For example, good results are obtained with electrodes in the form of conductive ribbons with a width of between a few millimeters and a few centimeters wide, preferably between 5mm and 10cm wide, more preferably between 5mm and 3.5cm wide. The thickness of the conductive electrodes is generally less than 100µm.

[0020] Generally, the central electrode will be wider than the width of the side electrodes so as to reduce its resistance by increasing its cross-section.

[0021] This results in a multi-layer heating structure that can be installed in cluttered rooms or rooms with obstacles requiring cutting operations. Indeed, depending on the location of an obstacle in the room, it may be necessary to cut out part of the multi-layer structure. By carrying out this cutting, part of the heating layer may be rendered unusable, for example due to the cutting of one of the conductive electrodes supported by the conductive strip. Since this cutting preserves part of the conductive strip arranged between two conductive electrodes, it is still possible to heat the room in which the multi-layer structure is installed by supplying power to the remaining conductive electrodes.

[0022] The use of a conductive strip supporting at least three electrodes arranged side by side and spaced from each other also makes it possible to obtain multi-layer coverings of all widths, for example a width greater than 1 meter, advantageously between 1 meter and 5 meters, and not modifying the duration of the floor or wall covering installation operation. In addition, the manufacture of this type of covering is facilitated insofar as the heating layer can be bonded in one pass, for example by lamination, to the conductive electrodes and to the decorative layer and / or to the underlayer.

[0023] Advantageously, the conductive strip supports at least two pairs of conductive electrodes, said electrodes being spaced from each other and configured so as to define a discontinuous heating surface. This embodiment is particularly advantageous because it generally makes it possible to use two pairs of electrodes of identical widths and therefore to simplify the manufacturing process of the multilayer structure and reduce its cost.

[0024] In a general but non-limiting manner, at least two pairs of electrodes extend substantially in a longitudinal direction and are arranged parallel to each other. A pair of electrodes is constituted by two electrodes spaced from each other only by the conductive strip so that an electrical potential difference applied to this pair of electrodes causes an electric current to flow in a single part of the conductive strip. Two electrodes of a pair of electrodes are generally spaced from each other by a distance greater than 5 cm, advantageously between 5 cm and 60 cm. Two pairs of electrodes are generally spaced from each other by a distance between the two closest electrodes of each pair of less than 5 cm, preferably between 0.5 and 3 cm.

[0025] To obtain a heating surface, each pair of electrodes has an electrical potential difference. For example, an electrical potential is applied to one of the electrodes of a pair and at least one different electrical potential is applied to the other electrode of the same pair, so as to obtain a current flow between the electrodes. This flow can in particular be obtained with a direct current or an alternating current. The heating surface obtained is considered to be discontinuous insofar as no heating is obtained over the width of the conductive strip supporting the conductive electrodes. Similarly, if the same electrical potential is applied to the two closest electrodes of each pair, no heating is obtained over the width of the conductive strip arranged between the pairs of electrodes. The electrodes are thus advantageously chosen to be very narrow, more advantageously in the form of conductive ribbons.

[0026] Advantageously, the heating layer comprises at least two conductive strips arranged side by side and spaced from each other, said conductive strips comprising conductive particles distributed homogeneously on the surface and / or in the thickness of said conductive strips, each conductive strip supporting two conductive electrodes spaced from each other so as to define a discontinuous heating surface.

[0027] In this way, the multi-layer structure thus obtained allows in particular a homogeneous distribution of the heating when the two conductive strips of said heating layer are crossed by an electric current. By applying an electric voltage between the two conductive electrodes supported by each conductive strip, the resistance of each conductive strip produces a release of heat by Joule effect distributed over the entire heating surface between the electrodes. The heat is then transmitted to the different layers of the multi-layer support, in particular the decorative layer, then to the room in which the structure is arranged, thus allowing the room to be heated.These conductive strips comprising conductive particles distributed homogeneously on the surface and / or in the thickness of said conductive strips, they can be partially cut or perforated without risking electrically insulating one part of the conductive strip from another. The heating surface obtained is considered to be discontinuous insofar as each conductive strip is independent and has its own pair of electrodes. One conductive strip can thus be crossed by an electric current without the other strip being operational.

[0028] Advantageously, the heating layer of the multilayer structure according to the invention thus comprises at least two conductive strips arranged side by side and spaced apart from each other. This makes it possible in particular to obtain a heating multilayer structure that can be installed in cluttered rooms or rooms with obstacles requiring cutting operations. Indeed, depending on the location of an obstacle in the room, it may be necessary to cut out a portion of the multilayer structure. By carrying out this cutting, a portion of the heating layer may be rendered unusable, for example due to the cutting of a conductive strip or one of the conductive electrodes supported by one of the two conductive strips. However, due to the presence of a second conductive strip, it is then still possible to heat the room in which the multilayer structure is installed by supplying power to the conductive electrodes supported by this second conductive strip.Furthermore, depending on the resistivity of the conductive strip, it may be difficult to obtain distances between two electrodes supported by the same conductive strip greater than 1 meter, or even greater than 50 cm, while maintaining supply voltage values ​​that do not endanger the occupants of the premises in which the multilayer structure according to the invention is arranged. The voltage value necessary to obtain a conventional heating power, of the order of a hundred Watts for one square meter of surface area of ​​said strip, is directly proportional to the distance between two electrodes supported by the same conductive strip.Therefore, the use of at least two conductive strips arranged side by side and spaced apart from each other also makes it possible to obtain multi-layer coverings of conventional width, for example a width greater than 1 meter, advantageously between 1 meter and 5 meters, and not modifying the duration of the floor or wall covering installation operation.

[0029] The conductive strips according to the invention comprise conductive particles distributed homogeneously on the surface and / or in the thickness of said conductive strips. A conductive strip according to the invention is made of a non-woven textile, comprising conductive particles distributed homogeneously on the surface and / or in the thickness of the strip. For example, a conductive strip may be made of a non-woven textile impregnated, coated or powdered with conductive particles. According to a variant not in accordance with the invention, a conductive strip may for example be made of a plastic material, in particular from PVC, acrylic or polyolefin, comprising conductive particles, such as carbon black particles, in a sufficient quantity for the strip thus obtained to be conductive.According to another variant not in accordance with the invention, a conductive strip can also be obtained by applying to the surface of a strip made from plastic material a paint comprising conductive particles, in a quantity sufficient for the strip thus obtained to be conductive.

[0030] By conductive, we preferably mean a resistivity value measured from one edge to another in the transverse direction of a conductive strip or, between two electrodes supported by the same conductive strip, less than 100 ohm / m, preferably less than 10 ohm / m, more preferably less than 5 ohm / m, even more preferably between 1 ohm / m and 5 ohm / m. Such resistivity values ​​make it possible to obtain heating powers of the order of a few hundred watts per square meter of coating, and this for supply voltages of the electrodes which do not endanger the occupants of the premises where the multilayer structures according to the invention are installed. Recommended supply voltages are in particular voltages in the very low voltage range, i.e. less than 110 Volts in direct current.Preferably, the supply voltages of the electrodes are less than 60 volts direct current or even less than 36 volts direct current. Alternating current voltage sources may also be used.

[0031] Advantageously, in the case where the multilayer structure according to the invention comprises at least two conductive strips, the electrodes are arranged along the longitudinal edges of the conductive strips. This makes it possible in particular to optimize the heating surface so that it extends over almost the entire surface of the multilayer structure thus formed. The heating surface thus produced extends in the longitudinal direction and between the electrodes supported by each conductive strip.

[0032] Advantageously, the multilayer structure according to the invention is produced in the form of a strip, the conductive strip(s) extending along said strip. This type of structure can thus be manufactured by a continuous process, the conductive strip(s) being for example unwound and then continuously bonded to the decorative layer and the underlayer as they advance in said continuous process. The direction of advancement of the process corresponds to the longitudinal direction of the strip thus formed. The invention thus makes it possible to obtain a multilayer structure which can be manufactured and then transported in the form of a roll.

[0033] Alternatively, the multilayer structure according to the invention is produced in the form of a strip, the conductive strip(s) extending transversely to said strip.

[0034] The conductive particles comprising the conductive strips may be carbon black particles, drops of conductive ink such as silver or carbon inks, carbon nanotubes, carbon fibers or the like.

[0035] A conductive strip made from a non-woven fabric can be made from glass fibers, but also from synthetic polymers, such as polyester, polyamide or polypropylene fibers. For example, it is possible to impregnate, coat or powder the non-woven fabric with conductive particles such as carbon particles or equivalent. In particular, a conductive strip can be made from a non-woven fabric impregnated with carbon fibers, silver ink or carbon ink. The advantage of a conductive strip made from an impregnated non-woven fabric is that it is conductive in a particularly homogeneous manner throughout the thickness of the strip, the conductive particles themselves being distributed homogeneously during the manufacture of said conductive strip.

[0036] A conductive strip made of a non-woven fabric can also be partially cut or perforated without risking electrically insulating one part of the conductive strip from another. It can also be easily handled in conventional continuous processes for manufacturing multi-layer structures for the production of floor or wall coverings, particularly in the form of rolls.

[0037] According to the invention, nonwoven textiles that can be used advantageously have a grammage of between 25 g / m 2 and 80 g / m 2 , advantageously between 25 g / m 2 and 40 g / m 2 . Such a grammage makes it possible in particular to obtain nonwoven textiles that can be arranged between layers of a multilayer structure and retain good bonding properties with a decorative layer and an underlayer made of thermoplastic material. A conductive strip made of a nonwoven textile can thus easily be heat-laminated or bonded with an underlayer and a decorative layer made of plastic material in a conventional floor covering manufacturing process. The impregnation by heat-laminated bonding of the decorative layers, the underlayer, and any adhesives is sufficiently deep in the thickness of the conductive strips made of a nonwoven textile so that they do not cause any risk of delamination.

[0038] Advantageously, each conductive strip made from a non-woven fabric can be used as a coating support in a method for manufacturing the multilayer structure according to the invention. For example, a conductive strip made from a non-woven fabric can be coated with a PVC or acrylic or polyolefin plastisol, then gelled in order to obtain the decorative layer or the underlayer of the multilayer structure according to the invention.

[0039] Advantageously, in the case where the multilayer structure according to the invention comprises at least two conductive strips, two conductive strips made of a non-woven textile are arranged side by side and spaced from each other and then complexed in order to be arranged in contact with the same reinforcing reinforcement, such as a glass veil and / or a glass grid, in order to obtain a reinforced coating support resistant to large tensile forces. In this way, a PVC or acrylic or polyolefin plastisol can be coated on the reinforced coating support obtained, then gelled in order to obtain the decorative layer or the underlayer of the multilayer structure according to the invention.

[0040] The decorative and undercoat layers are obtained in a conventional manner by coating, pressing, extrusion or calendering and from plastic materials such as PVC, acrylics, polyurethanes, polyolefins, as well as their mixtures, allowing a smooth and flat surface to be obtained.

[0041] The two electrodes supported by the same conductive strip are spaced from each other in order to avoid contact between them and can be supported by the same face, facing the decorative layer or facing the underlayer of said strip or supported by two opposite faces of said strip.

[0042] Advantageously, the electrodes are conductive strips, made for example of copper or aluminum. This makes it possible in particular to obtain electrodes of very low thickness, namely less than 100µm, thus limiting the well-known effect under the English acronym of "telegraphing" on the decorative layer. The "telegraphing" effect corresponds to the appearance of defects on the decorative layer of a floor covering in particular, due to the presence of irregularities in the support placed under the covering, such as clumps of glue or small asperities. This effect can also be observed when the structure of the covering includes a reinforcing grid. This effect is not necessarily visible during manufacturing but can appear after installation, or even after several months of use.

[0043] The electrodes can in particular be made from a copper or aluminum strip by cutting strips with a width of less than 5 cm, advantageously between 0.5 cm and 3.5 cm. Said strips are then glued onto each conductive strip using a conductive glue.

[0044] Advantageously, the heating layer comprises a dielectric layer bonded to the decorative layer and / or a dielectric layer bonded to the underlayer. A dielectric layer may be bonded, for example by heat-bonding, to the upper face of the heating layer, i.e. the face facing the decorative layer, or to the lower face of the heating layer, i.e. the face facing the underlayer. For example, it is possible to heat-bond a film obtained from Polyvinyl Chloride (PVC) to the upper and lower faces of the heating layer in order to obtain an assembly sufficiently strong to be handled by conventional in-line production processes, in particular processes for complexing multilayer structures made of thermoplastic materials such as PVC. A dielectric layer may also be obtained from Polyethylene (PE), Polyethylene terephthalate (PET) or any other non-conductive polymer.

[0045] Conventionally, the heating layer can be bonded by gluing, heat-sealing, hot-melt bonding, cold bonding, to the undercoat and the decorative layer.

[0046] The invention also makes it possible not to modify conventional installation techniques, the mechanical behavior during installation of the multilayer structure with or without the heating layer being comparable.

[0047] The advantage of the invention is also to propose a multi-layer structure of low thickness, namely less than 3 mm and of lower cost than conventional techniques allowing a heating function to be provided to a room, in particular via the floor or the walls.

[0048] The invention can also be used for exterior floor de-icing applications. Other applications are also conceivable. In particular, in the case where the decorative layer comprises thermochromic pigments, it is possible to produce multi-layer signage structures. Indeed, heating the multi-layer structure by the heating layer allows the thermochromic pigments to change color and thus display a message or logo in a particularly uniform manner.

[0049] The invention also makes it possible to provide a heating solution in a room without having to undertake major works. In the case where the multilayer structure is produced in the form of a roll, the installation consists of unrolling the roll on a clean support and connecting the electrodes to a direct or alternating current power source. The invention also makes it possible to easily adapt the multilayer heating structure to the constraints of the room, such as the presence of conduits, drains or attachment points and requiring the cutting of the floor or wall covering.

[0050] In this way, it is possible to renovate more quickly and with very little downtime of the premises while providing heating and protection functions for the floors and / or walls. This configuration makes it possible to significantly reduce the cost of the renovation.

[0051] Advantageously, the underlay of the multi-layer structure is a foam, for example obtained from a mixture of expanded polyvinyl chloride, plasticizer and filler. The presence of air trapped in the foam makes it possible in particular to improve thermal insulation and to promote the transmission of heat from the heating layer to the decorative layer, and therefore to the room.

[0052] Alternatively, the underlay is a compact underlay, i.e. one that does not contain bubbles, for example, made from polyvinyl chloride, plasticizer, and filler. A compact underlay allows the resulting multi-layer structure to have better puncture resistance.

[0053] Preferably, and to increase the mechanical performance and resistance to punching and rolling and to allow dimensional stability of the floor covering over time, the decorative layer and / or the underlay comprise a textile reinforcement frame, such as a grid or a glass veil.

[0054] In order to heat a room in which the multilayer structure according to the invention is arranged, each electrode is connected to a direct or alternating current source via a connector. The connection between the connectors and the electrodes can be made by any means capable of establishing and maintaining electrical contact. For example, a connector can in particular pass through the thickness of the multilayer structure opposite an electrode and be held by clipping, screwing or the like. Advantageously, the power supply to each connector can be interrupted by a control-command system, so as to be able to activate or deactivate certain heating surfaces, in particular in the case of moving a partition in rooms.Advantageously, the power supply to each connector can be modified by a control system, so as to be able to increase or decrease the temperature of certain heating surfaces.

[0055] The invention also relates to a method for the continuous manufacture of the multilayer structure according to the invention comprising the following steps: Obtain, for example by impregnation of conductive particles, a conductive strip made of a non-woven textile Bond to the conductive strip, for example by gluing using a conductive glue, at least three electrodes spaced from each other and configured so as to define a discontinuous heating surface Complex the conductive strip on a reinforcing frame such as a glass veil and / or a glass grid in order to obtain a reinforced coating support Coat the reinforced coating support with a Plastisol in order to obtain a decorative layer or an underlayer Heat-bond, coat, glue, or press on the back of the structure obtained in the previous step a decorative layer or, where appropriate, an underlayer made of a plastic material

[0056] The invention also relates to a method for the continuous manufacture of a variant of the multilayer structure according to the invention comprising the following steps: Obtain, for example by impregnation of conductive particles, two conductive strips made of a non-woven textile Bond by gluing using a conductive glue, two electrodes spaced from each other along the longitudinal edges of each conductive strip Complex side by side and spaced from each other the two conductive strips as obtained in the previous step either arranged in contact on a reinforcing frame such as a glass veil and / or a glass grid in order to obtain a reinforced coating support Coat on the coating support obtained in the previous step, a Plastisol in order to obtain a decorative layer or an underlayer Heat-bond, coat, glue, or press on the back of the structure obtained in the previous step a decorative layer or where appropriate an underlayer made of a plastic material SUMMARY DESCRIPTION OF THE FIGURES

[0057] Other advantages and characteristics will emerge more clearly from the following description, given by way of non-limiting example, of the multi-layer structure according to the invention for producing a heated floor or wall covering, from the attached drawings in which: there figure 1 illustrates, schematically and in cross-section, the multi-layer structure according to the invention; figure 2 illustrates, schematically and in top view, an exemplary embodiment according to the invention; figure 3 illustrates, schematically and in cross-section, an alternative multi-layer structure according to the invention; figure 4 illustrates schematically and in top view an alternative embodiment of the multilayer structure according to the invention. Figure 5 illustrates, schematically and in cross-section, a multi-layer structure according to the invention; figure 6illustrates, schematically and in top view, an exemplary embodiment according to the invention; figure 7 has a multi-layer structure according to the invention placed in a cluttered room; the figure 8 illustrates an alternative embodiment of the multilayer structure according to the invention. DETAILED DESCRIPTION OF THE INVENTION

[0058] In reference to the figure 1 , the invention relates to a multi-layer structure (1) for producing a floor or wall covering or similar heating material, i.e. allowing the heating of the room in which the structure according to the invention is installed.

[0059] The multi-layer structure (1) can be produced in the form of a panel, slab, strip or roll. The multi-layer structure (1) according to the invention is intended for the production of floor or wall coverings in glued, semi-loose or free installation, presenting high performance in terms of waterproofing and resistance to traffic.

[0060] The multi-layer structure (1) comprises an upper decorative layer (2) consisting of at least one surface layer (2a) of plastic material, bonded to a heating layer (4), said heating layer (4) being bonded to a lower sub-layer (3) intended to be laid on the floor or a wall or the like. The heating layer comprises a conductive strip (4a) comprising conductive particles distributed homogeneously on the surface and / or in the thickness of said conductive strip (4a), said conductive strip (4a) supporting at least three conductive electrodes (5a, 5b, 5c), said electrodes being spaced from each other and configured so as to define a discontinuous heating surface.

[0061] The upper decorative layer (2) and the lower sub-layer (3) can have various compositions and structures depending on the application considered.

[0062] For this purpose, the decorative layer (2) comprises a surface layer (2a) made of polyvinyl chloride comprising a thickness of between 0.2 and 1 mm. This surface layer (2a) may be mass-dyed and comprise decorative granules throughout its thickness. Preferably, and to satisfy, for example, the U4 P3 classification of the French UPEC standard, the surface layer (2a) comprises a density of between 1.4 and 1.6, a residual depression of less than 0.10 mm, and resistance to rolling chairs at 25,000 cycles. The surface layer (2a) may be transparent and associated with a decorative layer (not shown) printed on its reverse side, namely on its side opposite the heating layer (4). The printed decorative layer generally comprises a thickness of between 0.07 and 0.5 mm.

[0063] The decorative layer (2) is bonded for example by hot lamination, or by means of an adhesive layer (not shown) to the heating layer (4). The heating layer (4) comprises a conductive strip (4a) made of a non-woven textile impregnated with conductive particles, namely of glass fiber impregnated with carbon fibers, with a grammage of between 25 g / m 2< and 80 g / m 2< , advantageously between 25 g / m 2< and 40 g / m 2< . A conductive strip made of a non-woven textile of glass fibers impregnated with carbon fibers with a grammage of 30 g / m 2< has a resistance of between 4 and 5 Ohms over a distance of 40 cm.

[0064] The conductive strip (4a) supports at least three conductive electrodes (5a, 5b, 5c) spaced apart from each other so as to define a discontinuous heating surface. The heating surface thus extends between each electrode supported by the conductive strip. Obviously, the weight of the non-woven fabric of the conductive strip and the quantity of conductive particles can be adapted to obtain the desired resistivity value depending on the size of the heating surface.

[0065] The conductive electrodes (5a, 5b, 5c) are strips arranged in the center and along the longitudinal edges of the conductive strip (4a) in such a way that the heating surface extends over almost the entire surface of the multilayer structure thus formed. The heating surface thus obtained extends between the electrodes (5a, 5b) and (5b, 5c). In the case of a structure (1) produced in the form of a strip, the heating surface extends in the longitudinal direction of the produced strip and between the electrodes (5a, 5b) and (5b, 5c).

[0066] The electrodes (5a, 5b, 5c) are for example ribbons made from a 40 µm thick copper foil. The electrodes (5a, 5b, 5c) are for example bonded on each conductive strip by a 25 µm thick layer of conductive glue.

[0067] Advantageously, the heating layer (4) comprises a dielectric layer (6) bonded to the decorative layer (2).

[0068] Advantageously, the heating layer (4) comprises a dielectric layer (7) bonded to the sub-layer (3).

[0069] As regards the lower sub-layer (3), this comprises a balancing layer (3a) made of plastic, such as polyvinyl chloride, preferably having a thickness of 2 mm. Preferably, and to satisfy for example the U4 P3 classification of the French UPEC standard, the balancing layer (3a) has a Shore A hardness of between 80 and 95. This balancing layer (3a) may also be made of PVC or polyurethane foam to provide acoustic and / or thermal insulation properties to the floor or wall covering. In the case where this balancing layer (3a) is made of foam, its density is between 0.2 and 0.9.

[0070] This balancing layer (3a) is then bonded, for example by hot pressing, to the heating layer (4).

[0071] A textile reinforcement frame (not shown) may also be embedded in the underlayer (3) and / or the decorative layer (2). This reinforcement frame is, for example, in the form of a grid or a grid of textile threads of negligible thickness, or a glass veil. The textile threads of said reinforcement frame are preferably spaced apart from each other by 3 mm, according to the longitudinal and transverse dimensions, and comprise a linear mass of between 20 g / m and 70 g / m, advantageously between 35 g / m and 50 g / m. A reinforcement frame makes it possible to increase the mechanical performance and the resistance to punching and rolling of the floor or wall covering. The reinforcement frame also ensures dimensional stability of the covering over time.

[0072] The arrangement of the decorative layer (2) and the underlayer (3) are given as non-limiting examples. It is obvious that depending on the application considered, layers can be added to or removed from the multilayer structure (1) described.

[0073] For example, the multilayer structure (1) described below is intended for use, for example, in hospitals or in schools. The multilayer structure (1) has good mechanical performance in terms of resistance to punching and rolling, and incorporates heating functions.

[0074] In the case where the conductive strip (4a) is made of a non-woven textile, the conductive strip can be used as a coating support in a method for manufacturing the multilayer structure according to the invention. For this purpose, the conductive strip is complexed with a reinforcing reinforcement (8), such as a glass veil and / or a glass grid. This makes it possible to obtain a reinforced coating support. The width of the reinforcing reinforcement (8) is advantageously greater than the width of the conductive strip (4a). The electrodes (5a, 5b, 5c) are spaced from each other and then bonded to the conductive strip (4a). Alternatively, the electrodes (5a, 5b, 5c) are spaced from each other and then complexed on the reinforcing reinforcement (8).

[0075] In this way, a PVC or acrylic plastisol or a polyolefin can be coated on the reinforced coating support obtained and then gelled in order to obtain the decorative layer or the underlayer of the multilayer structure according to the invention.

[0076] A glass grid may be in the form of a grid or a grid of textile threads of negligible thickness, preferably spaced apart from each other by 3 mm, according to the longitudinal and transverse dimensions, and comprising a linear mass of between 20 g / m and 70 g / m, advantageously between 35 g / m and 50 g / m.

[0077] In reference to the figure 2, the invention also relates to a multilayer structure (1) produced in the form of a strip, for producing a heated floor or wall covering or the like, comprising a decorative layer (not shown), a heating layer and a lower sub-layer (3) of which the heating layer (4) comprises a conductive strip (4a) produced in a non-woven textile comprising conductive particles distributed homogeneously on the surface and / or in the thickness of said conductive strip (4a). The multilayer structure (1) is produced in the form of a strip and the conductive strip (4a) extends along said strip. The conductive strip (4a) supports three conductive electrodes, respectively (5a, 5b, 5c), spaced from each other and configured so as to define a discontinuous heating surface.The heating surface thus extends over almost the entire surface of the multi-layer structure (1) thus formed, in the longitudinal and transverse directions.

[0078] In this way, a large multi-layer structure can be obtained, while limiting heating losses due to too large a spacing between the electrodes supported by the conductive strip.

[0079] In order to heat a room in which the multilayer structure (1) according to the invention is arranged, each electrode is connected to a direct or alternating current source (20), via two connectors (21a, 21b). The connection between the connectors and the electrodes can be made by any means capable of establishing and maintaining electrical contact. For example, a connector can in particular pass through the thickness of the multilayer structure opposite an electrode and be held by clipping, screwing or the like. Advantageously, a part of the multilayer structure is arranged along a technical duct or a baseboard so as to hide the connectors in the technical duct or the baseboard and protect them.

[0080] The heating surface obtained is considered to be discontinuous insofar as no heating is obtained over the width of the conductive strip supporting the conductive electrodes, in particular the electrode (5b). The electrodes are thus advantageously chosen to be very narrow, more advantageously in the form of conductive strips. Generally, the electrode (5b) will be of a width greater than the width of the electrodes (5a, 5c) so as to reduce its resistance by increasing its cross-section. The electrode (5b) can be considered as a central electrode insofar as it is arranged between the electrodes (5a, 5c). The electrodes (5a, 5c) can be considered as lateral electrodes. In the example shown in the figure 2, a positive electric potential is applied to the electrode (5b), a negative potential is applied to the electrodes (5a, 5c). The current then flows in the parts of the conductive strip (4a) arranged between the electrodes (5a, 5b) and (5b, 5c).

[0081] In order to obtain a regulated heating system, the direct current source (20) can be controlled by a regulation system (30) connected to a temperature sensor (40) arranged in the room to be heated or linked to the decorative layer or the underlayer of the multilayer structure (1).

[0082] In reference to the figure 3 , an alternative embodiment not in accordance with the invention of the multilayer structure (1) comprises a conductive strip (4a) supporting at least two pairs of conductive electrodes (5a, 5b, 5a', 5b'), said electrodes being spaced from each other and configured so as to define a discontinuous heating surface.

[0083] In reference to the figure 4, a multilayer structure (1) according to the figure 3is produced in the form of a strip, for producing a heated floor or wall covering or the like, comprising a decorative layer (not shown), a heating layer and a lower sub-layer (3) of which the heating layer (4) comprises a conductive strip (4a) made of a non-woven textile comprising conductive particles distributed homogeneously over the surface and / or in the thickness of said conductive strip (4a). The multilayer structure (1) is produced in the form of a strip and the conductive strip (4a) extends along said strip. The conductive strip (4a) supports two pairs of conductive electrodes (5a, 5b, 5a', 5b'), spaced from each other and configured so as to define a discontinuous heating surface. The heating surface thus extends over almost the entire surface of the multilayer structure (1) thus formed, in the longitudinal and transverse directions.The heating surface obtained is considered to be discontinuous insofar as no heating is obtained over the width of the conductive strip supporting the conductive electrodes (5a, 5b, 5a', 5b'). Similarly, if the same electrical potential is applied to the two closest electrodes of each pair (5b, 5a'), no heating is obtained over the width of the conductive strip arranged between the electrodes (5b, 5a'). The electrodes are thus advantageously chosen to be very narrow, more advantageously in the form of conductive ribbons.

[0084] In reference to the Figure 5 , an alternative embodiment of the multilayer structure (1) not in accordance with the invention is shown.

[0085] The multi-layer structure (1) comprises an upper decorative layer (2) consisting of at least one surface layer (2a) of plastic material, bonded to a heating layer (4), said heating layer (4) being bonded to a lower sub-layer (3) intended to be laid on the floor or a wall or the like. The heating layer consists of at least two conductive strips (4a, 4a'), arranged side by side and spaced apart from each other, said conductive strips (4a, 4a') comprise conductive particles distributed homogeneously on the surface and / or in the thickness of said conductive strips (4a, 4a'), each conductive strip (4a, 4a') supports two conductive electrodes (5a, 5b, 5a', 5b') spaced apart from each other so as to define a discontinuous heating surface.

[0086] The heating layer (4) consists of two conductive strips (4a, 4a') arranged side by side and spaced apart from each other. The conductive strips (4a, 4a') are for example made of a non-woven textile impregnated with conductive particles, namely of glass fiber impregnated with carbon fibers, with a grammage of between 25 g / m 2< and 80 g / m 2< , advantageously between 25 g / m 2< and 40 g / m 2< . A conductive strip made of a non-woven textile of glass fibers impregnated with carbon fibers with a grammage of 30 g / m 2< has a resistance of between 4 and 5 Ohms over a distance of 40 cm.

[0087] Each conductive strip (4a, 4a') supports two conductive electrodes (5a, 5b, 5a', 5b') spaced apart from each other so as to define a discontinuous heating surface. The heating surface thus extends between each pair of electrodes supported by the same conductive strip. Obviously, the weight of the non-woven fabric of the conductive strip and the quantity of conductive particles can be adapted to obtain the desired resistivity value depending on the size of the heating surface.

[0088] The conductive electrodes (5a, 5b), (5a', 5b') are ribbons arranged along the longitudinal edges of the conductive strips (4a, 4b, 4a', 4b') in such a way that the heating surface extends over almost the entire surface of the multilayer structure thus formed. The heating surface thus obtained extends between the electrodes (5a, 5b) and (5a', 5b'). In the case of a structure (1) produced in the form of a strip, the heating surface extends in the longitudinal direction of the produced strip and between the electrodes (5a, 5b) and (5a', 5b').

[0089] Alternatively, the electrodes (5b) and (5a') are in electrical contact, and are for example obtained from a single conductive strip. In this case, the electrical connections of the electrodes (5a) and (5b') are then modified in order to keep two conductive strips (4a, 4a') powered independently. This configuration makes it possible to define a discontinuous heating surface of simpler construction. The single electrode corresponding to the electrodes (5b) and (5a') is for example powered by direct current at a voltage of 24 Volts, the electrodes (5a) and (5b') being connected to ground.

[0090] The electrodes (5a, 5b, 5a', 5b') are for example ribbons made from a 40 µm thick copper foil. The electrodes (5a, 5b, 5a', 5b') are for example bonded on each conductive strip by a 25 µm thick layer of conductive glue.

[0091] In the case where each conductive strip (4a, 4a') is made of a non-woven textile, said conductive strips can be used as a coating support in a method for manufacturing the multilayer structure according to the invention. For this purpose, each conductive strip made of a non-woven textile (4a, 4a') is arranged edge to edge and spaced from one another and then complexed in order to be arranged in contact with the same reinforcing reinforcement (8), such as a glass veil and / or a glass grid. This makes it possible to obtain a reinforced coating support. The width of the reinforcing reinforcement (8) is advantageously greater than the sum of the widths of the conductive strips arranged edge to edge in order to complex the conductive strips over their entire width on the reinforcing reinforcement. The electrodes (5a, 5b, 5a', 5b') are spaced apart from each other and then glued to each conductive strip (4a, 4a').Alternatively, the electrodes (5a, 5b, 5a', 5b') are spaced from each other and then complexed on the reinforcing frame (8), then each conductive strip (4a, 4a') is arranged edge to edge and spaced from each other and then complexed on the electrodes and the reinforcing frame (8).

[0092] In this way, a PVC or acrylic plastisol or a polyolefin can be coated on the reinforced coating support obtained and then gelled in order to obtain the decorative layer or the underlayer of the multilayer structure according to the invention.

[0093] In reference to the figure 6, according to an alternative embodiment not in accordance with the invention, a multilayer structure (1) is produced in the form of a strip, for producing a heated floor or wall covering or the like, comprising a decorative layer (not shown), a heating layer and a lower sub-layer (3) of which the heating layer (4) comprises three conductive strips (4a, 4a', 4a") produced from a non-woven textile comprising conductive particles distributed homogeneously on the surface and / or in the thickness of said conductive strips (4a, 4a', 4a"). The conductive strips (4a, 4a', 4a") are arranged side by side and spaced apart from each other. The multilayer structure (1) is produced in the form of a strip and the conductive strips (4a, 4a', 4a") extend along said strip.Each of the conductive strips (4a, 4a', 4a") supports two conductive electrodes, respectively (5a, 5b), (5a', 5b') and (5a", 5b") spaced from each other so as to define a discontinuous heating surface. The heating surface thus extends over almost the entire surface of the multilayer structure (1) thus formed, in the longitudinal and transverse directions.

[0094] In this way, a multi-layer structure of great width, preferably greater than 1.20 m, can be obtained while limiting the heating losses due to too great a spacing between the electrodes supported by the same conductive strip. Indeed, it is undesirable to have a distance between two conductive electrodes of the same conductive strip greater than 50 cm, the current necessary for heating said conductive strip being directly proportional to this spacing and quickly reaching dangerous electrical powers in inhabited premises.

[0095] Still according to the figure 6, for example, a multilayer structure (1) according to the invention is produced in the form of a strip with a width of approximately 1.20 m comprising three conductive strips (4a, 4a', 4a") made from a non-woven textile with a weight of 30 g / m 2< in glass fibers impregnated with carbon fibers, each strip measuring 40 cm in width. The strips are arranged side by side and spaced apart from each other in order to obtain a heating surface with a width of approximately 1.20 m. Each conductive strip supports two copper ribbons 1 cm wide and 45 µm thick, spaced apart from each other and glued with a 25 µm layer of conductive glue on the conductive strip. A few millimeters are left between the conductive electrodes (5b, 5a') and (5b', 5a") in order to limit the risks of short circuit.

[0096] For a conductive strip made of a non-woven fabric with a weight of 30 g / m 2< in glass fibers impregnated with carbon fibers with a width of 40 cm and a length of 300 cm, the measured resistance is between 4 and 5 ohms between two electrodes supported by the same conductive strip. Thus, with a 24 Volt direct current source, a heating power of 109W is obtained on the surface between two electrodes of the same conductive strip over a width of 40 cm and a length of 300 cm. With a 36V source, a heating power of 236W is obtained.

[0097] In reference to the figure 7 , the heating multilayer structure (1) according to the figure 6is shown schematically placed in cluttered premises with obstacles (50, 51) requiring cutting operations. In the example shown, it is necessary to cut out part of the multilayer structure in order to bypass the obstacles (50, 51). By carrying out this cutting, part of the heating layer is rendered unusable, for example due to the cutting of the electrode 5b". However, it is still possible to heat the premises in which the multilayer structure is placed by supplying power to the conductive electrodes (5a', 5b') supported by the conductive strip (4a'). The other conductive strips (4a, 4a") may also be supplied by their own electrodes in order to heat the surfaces opposite each of these conductive strips (4a, 4a''), the heating surface obtained being however reduced.

[0098] In reference to the figure 8, according to an alternative embodiment not in accordance with the invention, a multilayer structure (1) is produced in the form of a strip, for producing a heated floor or wall covering or the like, comprising a decorative layer (not shown), a heating layer and a lower sub-layer (3) of which the heating layer comprises three conductive strips (4a, 4a', 4a") comprising conductive particles distributed homogeneously on the surface and / or in the thickness of said conductive strips (4a, 4a', 4a"). The conductive strips (4a, 4a', 4a") are arranged side by side and spaced apart from each other. The multilayer structure (1) is produced in the form of a strip and the conductive strips (4a, 4a', 4a") extend transversely to said strip.Each of the conductive strips (4a, 4a', 4a") supports two conductive electrodes, respectively (5a, 5b), (5a', 5b') and (5a", 5b") spaced from each other so as to define a discontinuous heating surface.

[0099] Preferably, the heating layer (4) comprises a dielectric layer (6) bonded to the decorative layer (2) and a dielectric layer (7) bonded to the sub-layer (3) in order to electrically insulate this layer from the other layers of the multi-layer structure according to the invention. The conductive strips (4a, 4a') as well as the electrodes (5a, 5b, 5c, 5a', 5b', 5a", 5b") that they support are thus sandwiched between the two dielectric layers (6, 7). A dielectric layer can in particular be obtained from a PVC or Polyethylene terephthalate (PET) film or any other non-conductive polymer and bonded for example by heat-sealing.

[0100] A dielectric layer can also serve as a support for producing the heating layer. For this purpose, each conductive strip, for example a conductive strip made of a non-woven fabric, is arranged edge to edge and spaced from each other and then cold-laminated with a dielectric layer (7) serving as a support. The electrodes are subsequently spaced from each other and then glued onto each conductive strip. Advantageously, a second dielectric layer (6) is laminated onto each conductive strip so as to sandwich the two conductive strips, and the electrodes they support, between the dielectric layers (6) and (7) and to obtain an assembly that can be directly laminated with a decorative layer and an underlayer.

[0101] Advantageously, and whatever the embodiment, the heating layer (4) may comprise a reinforcing frame (8) linked to the decorative layer (2) and / or linked to the underlayer (3) arranged in contact with the conductive strip(s) (4a, 4a', 4a"). A reinforcing frame (8) makes it possible in particular to increase the mechanical performance and the resistance to punching and rolling of the floor or wall covering. The reinforcing frame also ensures dimensional stability of the covering over time.

[0102] It is clear from the above that the invention provides a multi-layer structure (1) for producing a heated floor or wall covering or similar, in glued, semi-loose or loose installation, making it possible to achieve high classification levels in terms of resistance to traffic and waterproofing, while guaranteeing rapid, nuisance-free and inexpensive renovation of a room and which integrates efficient heating functions.

Claims

1. Multilayer structure (1) for the realization of a heated floor or wall covering or similar for a dwelling or premises, said multilayer structure (1) comprising a decorative layer (2) consisting of at least one surface layer (2a) made of plastic material, said decorative layer (2) being bonded to a heating layer (4), said heating layer being bonded to an underlayer (3) intended to be placed on the floor, a wall, or a similar surface, the heating layer (4) comprising a conductive strip (4a) made of a textile incorporating conductive particles distributed homogeneously over the surface and / or throughout the thickness of the textile, said conductive strip (4a) supporting at least three conductive electrodes (5a, 5b, 5c), said electrodes being spaced apart from each other and electrically powered to define a discontinuous heating surface, characterized in that the textile of the heating layer is a non-woven textile and in that the surface layer (2a) is made of polyvinyl chloride (PVC) and has a thickness between 0.2 and 1 mm, and the underlayer is obtained by coating, pressing, extrusion, or calendering and made of PVC.

2. Multilayer structure (1) according to claim 1, characterized in that the conductive strip (4a) supports at least two pairs of conductive electrodes (5a, 5b, 5a', 5b'), said electrodes being spaced apart from each other and electrically powered to define a discontinuous heating surface.

3. Multilayer structure (1) according to one of claims 1 to 2, characterized in that the multilayer structure (1) is formed as a strip, with the conductive strip(s) (4a, 4a') extending along said strip.

4. Multilayer structure (1) according to one of claims 1 to 2, characterized in that the multilayer structure (1) is formed as a strip, with the conductive strip(s) (4a, 4a') extending transversely to said strip.

5. Multilayer structure (1) according to one of the preceding claims, characterized in that the thickness of the electrodes (5a, 5b, 5c, 5a', 5b') is less than 100µm.

6. Multilayer structure (1) according to one of the preceding claims, characterized in that the heating layer (4) comprises a dielectric layer (6) bonded to the decorative layer (2) and a dielectric layer (7) bonded to the underlayer (3).

7. Multilayer structure (1) according to claim 1, characterized in that the non-woven textile has a weight between 25 g / m2 and 80 g / m2.

8. Multilayer structure (1) according to one of claims 1 to 12, characterized in that the conductive particles contained in the conductive strip(s) (4a, 4a') are carbon fibers.

9. Multilayer structure (1) according to one of the preceding claims, characterized in that the heating layer (4) comprises a reinforcement framework (8) arranged in contact with the conductive strip(s) (4a, 4a').