DECORATIVE PANEL AND DECORATIVE FLOOR COVERING CONSISTING OF SAID PANELS.

Abstract

In the field of decorative floor coverings, decorative panels are known that have a core layer based on MDF (medium-density fiberboard) or HDF (high-density fiberboard) onto which a decorative substrate is bonded to give the panels the desired appearance. The invention relates to a panel, in particular a decorative panel, a floor panel, a ceiling panel, or a wall panel. The invention also relates to a floor covering consisting of a plurality of panels joined together.

Description

The invention relates to a panel, in particular a decorative panel, a floor panel, a ceiling panel, or a wall panel. The invention also relates to a floor covering consisting of a plurality of panels connected together. In the field of decorative floor coverings, decorative panels are known to have a core layer based on MDF (medium-density board) or HDF (high-density board), on which a decorative substrate is fixed to give the panels the desired appearance. A major disadvantage of these well-known panels is the hygroscopic nature of the core layer, which affects the panels' lifespan and durability. For this reason, traditional MDF / HDF-based panels are increasingly being replaced by polyvinyl chloride (PVC)-based panels, also provided with a decorative substrate on top. These PVC-based panels have the advantage of being relatively waterproof compared to MDF / HDF-based panels.However, the drawback of these PVC-based panels is their very poor temperature resistance, as a result of which they typically warp (bend) easily if exposed to a heat source, such as a radiator or even a lamp. Furthermore, an additional major drawback common to both MDF / HDF-based and PVC-based panels is their flammability. The flammability of furniture is a concern since, for example, accidents involving cigarettes and candles can easily trigger house fires. Therefore, there is a general need in the field of decorative flooring to develop more decorative panels to counter at least one of the above drawbacks and, in particular, to develop a decorative panel that is relatively fire-resistant.There is a further need to develop a decorative panel that has improved dimensional stability when subjected to temperature fluctuations during regular use. It is an objective of the invention to satisfy at least one of the needs mentioned above. The above objective of the invention is met by providing a panel, in particular a decorative panel, according to the above preamble, comprising: a core provided with an upper side and a lower side, a decorative upper structure fixed on said upper side of the core, a first panel edge comprising a first coupling profile, and a second panel edge comprising a second coupling profile which is designed to interlock with said first coupling profile of an adjacent panel, both in the horizontal direction and in the vertical direction, wherein said core comprises: at least one composite layer comprising: at least one composition based on magnesium oxide (magnesia) and / or magnesium hydroxide, in particular a magnesia cement; particles, in particular cellulose-based particles, dispersed in said magnesia cement; and, preferably,at least one reinforcing layer embedded in said composite layer. It is found that the application of a composition based on magnesium oxide and / or magnesium hydroxide, and in particular a magnesia cement, significantly improves the flammability (non-combustibility) of the decorative panel as such. Furthermore, the relatively fire-resistant panel according to the invention also has significantly improved dimensional stability when subjected to temperature fluctuations during normal use. The magnesia-based cement is a magnesia-based cement (magnesium oxide), wherein the cement is the reaction product of a chemical reaction in which magnesium oxide acts as one of the reactants. In the magnesia cement, the magnesia may still be present and / or undergo a chemical reaction in which another chemical bond is formed, as will be explained in more detail below. Additional advantages of the magnesia cement,Also compared to other types of cement, are presented below. A first additional advantage is that magnesia cement can be manufactured in an energy-efficient and therefore cost-effective manner. Furthermore, magnesia cement has a relatively high compressive and tensile strength. Another advantage of magnesia cement is that this cement has a natural affinity for cellulose materials, typically inexpensive, such as plant fibers, wood dust (wood powder), and / or wood chips. This not only improves the bonding of the magnesia cement but also leads to weight savings and more sound insulation (damping). Magnesium oxide, when combined with cellulose and, optionally, clay, creates water vapor-respiring magnesia cements; this cement does not deteriorate (rot) because it efficiently expels moisture. Furthermore, magnesia cement is a relatively good insulating material.both thermally and electrically, making the panel according to the invention particularly suitable for floors in radar stations and hospital operating rooms. A further advantage of magnesia cement is that it has a relatively low pH compared to other types of cement, which allows for greater durability of the glass fiber, either as particles dispersed in the cement matrix and / or (as glass fiber) as a reinforcing layer, and furthermore allows for the use of other types of fibers in a durable manner. bi cban / i ζηζ / α / γίΛΐ Furthermore, an additional advantage of the decorative panel is that it is suitable for both indoor and outdoor use. As already mentioned, magnesia cement is based on magnesium oxide and / or magnesium hydroxide. Magnesia cement itself can be free of magnesium oxide, depending on the additional reagents used to produce the magnesia cement. Here, for example, it is quite conceivable that magnesia as a reagent is converted into magnesium hydroxide during the magnesia cement production process. Therefore, magnesia cement itself can comprise magnesium hydroxide. Typically, magnesia cement comprises water, particularly hydrated water. Water is typically used as a binder to create a strong and coherent cement matrix. In one embodiment of a crystal according to the invention, the magnesia-based composition, in particular the magnesia cement, comprises magnesium chloride (MgCh). Typically, when magnesia (MgO) is mixed with magnesium chloride in an aqueous solution, a magnesia cement comprising magnesium oxychloride (MOC) will be formed. The bonding phases are Mg(OH)2, 5MG(OH)2.MgC12.8H2O (form 5), 3Mg(OH)2.MgC12.8H2O (form 3) and Mg2(OH)CICO3GH2O. Form 5 is the preferred phase, since this phase has superior mechanical properties. Relative to other types of cement, such as Portland cement, MOC has superior properties. MOC does not require moist curing, has high fire resistance, low thermal conductivity, and good abrasion resistance. MOC cement can be used with various aggregates (additives) and fibers with good bond strength. It can also be treated with various types of surface treatments.MOC develops a high compressive strength within 48 hours (e.g., 8,000–10,000 psi). The increase in compressive strength occurs early in the curing process; the 48-hour strength will be at least 80% of the maximum strength. The compressive strength of MOC is preferably between 40 and 100 N / mm2. The flexural tensile strength is preferably 10–17 N7mm2. The surface hardness of MOC is preferably 50–250 N / mm2. The E modulus is preferably 1–3 104 N7mm2. The flexural strength of MOC is relatively low but can be significantly improved by the addition of fibers, particularly cellulose-based fibers. MOC is compatible with a wide variety of plastic fibers, mineral fibers (such as basalt fibers), and organic fibers such as bagasse, wood fibers, and hemp. The MOC used in the panel according to the invention may be enriched with one or more of these types of fibers.MOC is non-shrinking, abrasion resistant, and resistant to wear, impact, indentation, and scratches. MOC is resistant to heat and freeze-thaw cycles and does not require air entrainment to improve durability. Furthermore, MOC has excellent thermal conductivity, low electrical conductivity, and excellent bonding to a variety of substrates and additives, and has acceptable fire resistance properties. MOC is less preferred if the panel is exposed to relatively extreme weather conditions (temperature and humidity), which affect both the setting properties and the development of the magnesium oxychloride phase. Over a period of time, atmospheric carbon dioxide will react with the magnesium oxychloride to form a surface layer of Mg2(OH)C10Cl3.3H2O. This layer serves to slow the leaching process.Finally, further leaching results in the formation of hydromagnesite, 4MgO.3CO3.4H2O, which is insoluble and allows the cement to maintain structural integrity. In a preferred embodiment of the panel according to the invention, the magnesium-based composition, and in particular the magnesia cement, is based on magnesium sulfate, in particular epsomite mineral sulfate heptahydrate, (MgSO4-7H2O). The latter salt is also known as Epsom salt. In aqueous solution, MgO reacts with MgSO4, giving rise to magnesium oxysulfate cement (MOS), which has very good binding properties. In MOS, 5Mg(OH)2.MgSO4.8H2O is the most frequently found chemical phase. Although MOS is not as strong as MOC, MOS is more suitable for fire-resistant uses, since MOS begins to decompose at temperatures more than twice as high as MOC, thus providing longer fire protection. Furthermore, its decomposition products at high temperatures are less harmful (sulfur dioxide) than those of oxychloride (hydrochloric acid) and, furthermore, less corrosive.Furthermore, climatic conditions (humidity, temperature and wind) during application are not as critical with MOS as with MOC. The mechanical strength of MOS cement depends mainly on the type and relative content of crystalline phases in the cement. It is found that there are four basic magnesium salts that can contribute to the mechanical strength of MOS cement in the thematic system MgO-MgSO4- H2O at different temperatures between 30 and 120 degrees Celsius: 5Mg(OH)2-MgSO4-3H2O (phase 513), 3Mg(OH)2 MgSO4-8H2O (phase 318), Mg(OH)2-2MgSO4-3H2O (phase 123) and Mg(OH)2MgSO4-5H2O (phase 115). Normally, phase 513 and phase 318 could only be obtained by curing the cement under saturated steam conditions when the molar ratio of MgO and MgSO4 was set at (approximately) 5:1. Phase 318 is found to contribute significantly to the mechanical strength and is stable at room temperature, so its presence in the applied SOM is preferred.This also applies to the 513 phase. The 513 phase typically has a (micro)structure comprising a needle-like structure. This can be verified by means of SEM analysis. Magnesium oxysulfate needles (5Mg(OH)2-MgSO4-3H2O) can form substantially uniformly, and will typically be 10-15 μm long and 0.4-1.0 μm in diameter. When referring to a needle-like structure, a scaly structure and / or a whisker structure can also be meant. In practice, it does not appear feasible to obtain MOS comprising more than 50% of the 513 or 318 phase, but by adjusting the crystal phase, composition can be applied to improve the mechanical strength of MOS. Preferably, the magnesia cement comprises at least 10%, preferably at least 20% and more preferably at least 30% of 5Mg(OH)2*MgSO4*3H2O (phase 513).This preferred embodiment will provide a magnesia cement that has sufficient mechanical strength for use in the core layer of a floor panel. The crystalline phase of SOM is tunable by modifying the SOM using an organic acid, preferably citric acid, and / or by phosphoric acid and / or phosphates. During this modification, new phases of SOM can be obtained, which can be expressed as 5Mg(OH)2.MgSO4.5H2O (phase 515) and Mg(OH)2*MgSO4«7H2O (phase 517). Phase 515 can be obtained by modifying the SOM using citric acid. Phase 517 can be obtained by modifying the SOM using phosphoric acid and / or phosphates (H3PO4, KH2PO4, KsPO4 and K2HPO4). These phases 515 and 517 can be determined by chemical element analysis, where SEM analysis demonstrates that the microstructure of both phase 515 and phase 517 is a needle-shaped crystal, insoluble in water. In particular, the compressive strength and water resistance of MOS can be improved by the addition of citric acid.Therefore, it is preferred that MOS, if applied in the panel according to the invention, comprises 5Mg(OH)2.MgSO4.5H2O (phase 515) and / or Mg(OH)2*MgSO4*7H2O (phase 517). As mentioned above, adding phosphoric acid and phosphates can extend the setting time and improve the compressive strength and water resistance of the MOS cement by changing the hydration process of MgO and the phase composition. Here, the phosphoric acid or phosphates ionize in solution to form H2PO4'. HPO42and / or PO43-, where these anions adsorb on [Mg(OH) (H2O)x]+ to inhibit the formation of Mg(OH)2 and further promote the generation of new magnesium subsulfate phase, which leads to the compact structure, high mechanical strength and good water resistance of MOS cement. The improvement brought about by the addition of phosphoric acid or phosphates to MOS cement follows the order of H3PO4= KH2PO+ » K2HPO4>> K3PO4.MOS has better volumetric stability, less shrinkage, better bonding properties and lower corrosivity under a significantly wider range of climatic conditions than MOC and could therefore be preferred over MOS. The density of MOS typically ranges from 350 to 650 kg / m3. The flexural tensile strength is preferably 1-7 N / mm2. In another preferred embodiment, the magnesium-based composition, particularly the magnesia cement, comprises magnesium phosphate cement (MPC). Preferred MPCs are magnesium ammonium phosphate cement (MAPC) and magnesium potassium phosphate cement (MKPC). MAPC results from a chemical reaction between magnesium oxide and a soluble phosphate, such as ammonium phosphate (NH4H2PO4), also referred to as ADP, either the mono- or dibasic salt. Alternatively, an agricultural fertilizer solution known as 10-340 (NPK designation) can also be used. MAPC has a rapid set and very high early strength. It has very good adhesion to a wide variety of compatible aggregates (additives). A wide variety of insoluble phases of ammonium and magnesium phosphate are formed, but struvite (NH4MgPO4*6H2O) and dittmarite (NILMgPC^EEO) are believed to be the principal phases.The ratio of these phases is determined by the reaction rate, with dittmarite predominating at a rapid rate and struvite predominating at a slower rate. At temperatures above 55°C, struvite decomposes, releasing water and ammonia from its structure. The resulting material has an amorphous structure that chemically corresponds to MgHPO. Excess ADP is added to ensure a complete and proportional reaction. MKPC is formed by the reaction of MgO with monopotassium phosphate (KHPO), referred to as MKP. The final reaction product is identified as magnesium potassium phosphate hexahydrate (MgKPO*6HO). Several intermediate phases are formed during the reaction as the pH and temperature vary.Both increasing the magnesium-to-phosphate molar ratio (M / P) and decreasing the liquid-to-solid weight ratio can accelerate the reaction rate. Due to the very rapid reaction rate, the MgO typically used burns to death in both MAPC and MKPC. Retarders, usually borates, are preferentially used during the formation of both MAPC and MKPC to achieve a manageable reaction time. MPC develops high compressive strength within the range of 5,000–10,000 psi (35–70 MPa). MPC does not lose strength over time under normal exposure conditions. Several factors can affect strength development, with the greatest observed effects being the reactant ratios (M / P), the w / w ratio, the amount of retarders used, and the materials added as fillers / aggregates to the binder.6 bi cban / i ζηζ / α / γίΛA flexural strengths of 600 to 2000 psi (4-14 MPa) were found with little effect on strength due to reactant ratios. Fibers, such as cellulose-based fibers, particularly wood fibers and / or hemp fibers, are preferably added to the MPC, as this will improve the flexural strength. The use of additives and fibers results in useful formulations for flexural reinforcement of magnesia cement by using at least one glass mesh. MPC, and particularly MKP, exhibit minimal shrinkage, excellent freeze-thaw resistance, and very low permeability. It also has a low coefficient of thermal expansion, relatively good corrosion protection, and relatively high abrasion resistance. Immersion in a magnesium sulfate solution is preferably performed to increase the strength of the formed MPC. As mentioned above, the addition of citric acid and / or a derivative thereof, particularly citrate, is preferred, as this will improve the panel's strength. The composite layer may, for example, comprise and / or be formed at least partially by using up to 0.5% by weight of citric acid. However, it is also conceivable for the composite material to subsequently comprise up to 1% by weight of citric acid and possibly up to 2% by weight. Typically, the composite layer comprises at least 0.1% by weight of citric acid, and preferably at least 0.2% by weight. The same applies to the addition of sodium silicate, particularly when the combination of citrate and sodium silicate is applied in a 1:1 ratio. In the latter case, the flexural strength can even be doubled. The addition of sodium bicarbonate significantly improved the water resistance of magnesia cements and is therefore also preferred.Adding dolomite, magnesite, or other fillers at a 40-60% binder level can absorb some heat and reduce the chances of thermal damage. cracking of the formed magnesia cement and can therefore also be advantageously applied. The composite layer preferably comprises at least one mineralizer selected from the group consisting of: sodium hydroxide (NaOH), calcium chloride (CaCh), aluminum sulfate (AhCSCCh) and calcium hydroxide Ca(OH)2. As mentioned above, the panel according to the invention typically comprises cellulose-based particles, in particular lignocellulose-based particles. Preferably, the cellulose-based particles comprise wood and / or hemp. Previous research shows that wood and hemp are chemically heterogeneous and their components can be divided into two groups: structural components of high molecular weight natural polymeric substances (cellulose, hemicelluloses and lignin), which are the main components of the cell wall, and low molecular weight non-structural components (extractive and inorganic components).Both wood and wood fibers comprise many chemical components, but the main inhibitor of cement hydration was found to be sugar. Various chemical treatments are preferentially applied to natural fibers, such as wood fibers or hemp fibers, before mixing them with the (initially fluid) magnesia cement. The compressive strength and other mechanical properties of treated wood fiber composites are higher than those of untreated fibers. Chemicals such as sodium hydroxide (NaOH), calcium chloride (CaCl), and aluminum sulfate (AgSO4), sometimes also referred to as mineralizing agents (mineralizers), typically improve the compatibility of cement and plant-based aggregates. Complex minerals such as Ah(SO4)3 + Ca(OH)2 can also be applied.When Ah(SO4)3 is used as a mineralizer, it prevents the release of sugar from organic aggregates and reduces hygroscopicity and water absorption. AhSCUh in the form of hydrate is characteristic of an acidic reaction in water, and calcium hydroxide [Ca(OHh)] is characteristic of an alkaline reaction in water. Mineralization is achieved by improving the efficiency of Ah(SO4)3, which at least partially neutralizes the acidic environment caused by AhíSCUh and improves the workability of the mixture. Mineralization of the wood aggregate also leads to improved adhesion between wood particles and magnesia cement, as a result of which a more stable and coherent magnesia cement can be obtained. As mentioned above, at least part of the cellulose-based particles are fibers. It is also conceivable that at least part of the cellulose-based particles are dust, wood shavings, wood wool, and / or wood chips. Instead of wood, other natural fibers, such as hemp, can also be used. Hemp-enriched magnesia cement also exhibits relatively good thermal insulation, excellent water properties, high acoustic properties, and good fire resistance. Here, hemp shavings are typically used as the coarse aggregate (basic component). As with wood, the hemp shavings are preferentially mineralized by hydroxybenzoates (AHC), neutralized with Ca(OH) and mixed with the magnesia cement (initially fluid / liquid). The composite layer preferably comprises at least one additional filler selected from the group consisting of: steel, glass, polypropylene, wood, acrylic, alumina, curaua, carbon, cellulose, coconut, Kevlar, nylon, Perlon, polyethylene, PVA, rock wool, sisal and fique. This may further increase the strength of the panel and / or the water resistivity and / or the fire-resistant properties of the panel as such. Preferably, the composite layer comprises sodium carboxymethylcellulose (CMC). It was found that the addition of CMC to the composite layer (during production) facilitates and even promotes the self-degradation of said magnesium-based composite layer, in particular a magnesia cement, in an alkaline aqueous environment and at elevated temperature (200 °C or higher). This will therefore improve the biodegradability of the panel. At this elevated temperature, the CMC emitted two main volatile compounds, CO2 and acetic acid, which creates a porous structure in the cement. The CMC also reacted with sodium silicate NaOH, if applied, to form three water-insensitive solid reaction products, disodium glycolate salt, sodium glucosidic salt, and sodium bicarbonate. Other water-sensitive solid reaction products, such as sodium polysilicate and sodium carbonate, were derived from sodium silicate hydrolysates.The dissolution of these products upon contact with water generated heat that promoted the self-degradation of the cement. Thus, CMC, particularly the high-molecular-weight CMS of MW 30,000, contributed two important features to the water-catalyzed self-degradation of heated cement: One was the high thermal energy generated in exothermic reactions in the cement; the other was the introduction of high porosity into the cement. Here, for example, it is conceivable that the composite layer comprises 50 parts of magnesium oxide, 20 parts of magnesium sulfate solution, 7 parts of coarse wood fiber (or flour), 5 parts of fine wood fiber (or flour), 3 parts of other reinforcing fibers, 3 parts of sodium silicate, 0.3 parts of sodium carboxymethylcellulose (CMC), and optionally 3 parts of fly ash. Fly ash typically replaces magnesium-based ingredients to save costs.Fly ash is often a byproduct of power plants and is typically classified as a pozzolanic material that can be used as a mineral additive for magnesia cement. Fly ash can reduce the initial heat of hydration of cement, the shrinkage rate of magnesia cements, and the porosity of cement stone, as well as improve cement stone density and physical and mechanical properties. Fly ash has been shown to improve the rheology of magnesia cement, although typically at the expense of compressive strength. Consequently, the amount of fly ash in the composite layer, particularly the magnesia layer, is preferably limited to an amount equal to or less than 10% by weight. Preferably, the composite layer comprises silica fume. Silica fume, also known as microsilica, is an amorphous (non-crystalline) polymorph of silicon dioxide, silica. It is an ultrafine powder collected as a by-product of the production of silicon and ferrosilicon alloys and typically consists of spherical particles with an average particle diameter of 150 nm. By incorporating silica fume into the composite layer, particularly magnesia cement, the water resistivity as well as the flame-retardant properties can be significantly improved. However, silica fume can affect the compressive strength of the composite layer, as a result of which the amount of silica fume is preferably limited to an amount equal to or less than 10% by weight. The composite layer may comprise iron oxide (FCI), preferably in an amount less than 6% by weight. Iron oxide imparts color to the cement. Furthermore, at very high temperatures, iron oxide chemically reacts with calcium and aluminum, which may also be present in the composite layer, to form tricalcium alumino-ferrite, which material (tricalcium aluminoferrite) improves the hardness and strength of the composite layer. Preferably, the amount of alumina (AI2O3) in the composite layer is between 3 and 8% by weight. Preferably, the amount of calcium sulfate required for the aforementioned reaction will typically be up to (and including) 0.5% by weight. The composite layer preferably comprises fatty acids. The fatty acids can penetrate the channels (pores) of the raw magnesite before grinding and will facilitate the grinding process (efficiency) to produce magnesia-based cement powder. The composite layer may comprise at least one alkali metal sulfate, such as magnesium sulfate. This will typically speed up the production process of the composite layer. Although one or more composite layers are preferably polymer-free, it is conceivable that one or more composite layers comprise at least one polymer, such as polyvinyl chloride (PVC), polystyrene (PS), and / or polyurethane (PUR). The PS may be in the form of expanded PS (EPS) to further reduce the density of the panel, which leads to cost savings and facilitates handling of the panels. Other polymers, in particular thermoplastics, may also be used. It is also conceivable that rubber components (particles) are dispersed within at least one composite layer to improve flexibility at least to a certain extent. At least one polymer, if applied, may be applied within the composite layer in the form of a sheet (closed layer), a mesh (woven), a nonwoven fabric, and / or as separate polymer particles (such as fibers, beads, spheres, etc.).In case a polymer layer is applied, the layer is preferably enclosed 10 bi cban / i ζηζ / α / γίΛA on both sides by composite material and is therefore preferably embedded within said composite layer. Preferably, the composite layer comprises perlite, preferably expanded (foamed) perlite. Perlite is an amorphous volcanic glass with a relatively high water content, typically formed by the hydration of obsidian. Perlite has the unusual property of expanding greatly when sufficiently heated, which could significantly reduce the density of the composite layer and thus of the panel as such. It is preferred that the composite layer further comprises foamed perlite of various particle size values. Closed-cell foamed perlite can lead to the achievement of a (perlite) porosity of 30-40%. Such perlite can be pre-processed with silicone solutions, sodium, potassium, and lithium silicates. The composite layer may further comprise one or more additive materials, advantageously including surface-active substances (SAS) such as methylcellulose, Badimol plasticizers, and other cationic SAS active materials to improve the rheology of the mixture. The composite layer may also comprise bentonite, a finely ground natural product designed to enhance the thermoplastic and waterproofing characteristics of the panel itself. The composite layer may also comprise at least one flame-retardant additive. This fire-retardant additive is preferably composed of an organic halogen compound. The compounds can scavenge reactive H and OH radicals during a fire. The organic halogen compound preferably comprises bromine and / or chlorine. An organic bromine compound such as PBDE (polybrominated diphenyl ether) is recommended for fire retardancy over an organochlorine compound such as PCB (polychlorinated biphenyl). Other examples of applicable brominated compounds are: Tetrabromobisphenol A, decabromodiphenyl ether (Deca), octabromodiphenyl ether, tetrabromodiphenyl ether, hexabromodiphenyl ether, hexabromocyclododecane (HBCD), tribromophenol, bis(tribromophenoxy)ethane, tetrabromophenoxy)ethane, tetrabromophenol A (TBB) tetrabromophenol A (TBB) polycarbonate oligomer or tetrab acid anhydride.Other examples of applicable chlorinated compounds are: chlorinated paraffin, bis(hexachlorocyclopentadiene) cyclooctane, pentacyclodecane dodecachloride (Dechlorane) and 1,2,3,4,7,8,9,10,13,13,14,14dodccachloro-1,4,4,5,6,6a,7,10,10a,ll,12,12a-dodccahydro-l,4,7,10-dimctanedibcnzo[a,c]cyclooctene (Dechlorane Plus). Although halogenated flame retardants are particularly effective, they generally have the disadvantage that they can produce toxic smoke in the event of a fire. Therefore, the application of one or more alternative, less toxic fire retardant additives, including intumescent (foaming) substances, may also be considered. The operating principle of these alternative additives is based on the formation of a foam layer that acts as an oxygen barrier and therefore also has a fire-retardant effect. Intumescent additives generally contain melamine or a salt derived from it.An example of this is a mixture of polyphosphates (acid donor) in coaction with melamine (foaming agent) and a carbon donor such as dipentaerythritol, starch, or pentaerythritol. Gaseous products such as carbon dioxide and ammonia gas are formed here in the event of a fire. The resulting foam layer is stabilized by crosslinking, as in vulcanization. Other examples of applicable and relatively environmentally friendly melamine-based additives are melamine cyanurate, melamine polyphosphate, and melamine phosphate. To save weight and, therefore, costs, it may be advantageous for the composite layer to be at least partially foamed. The foam structure may comprise open pores (cells) and / or closed pores (cells). Although the composite layer(s) may be provided with one or more plasticizers, such as phthalates, to provide more flexibility to the composite layer(s) (and to the panel as such), it is preferred that each composite material is preferably free of any plasticizer to increase the rigidity of the panel core, and which is also favorable from an environmental point of view. At least one reinforcing layer is preferably a nonwoven layer or a woven layer, in particular a fabric, for example made of glass fiber. They may have a thickness of 0.2 to 0.4 mm. It is also conceivable that each tile comprises a plurality of the (usually thinner) base layer stacked on top of each other, where at least one reinforcing layer is located between two adjacent base layers. Preferably, the density of the reinforcing layer is preferably between 1000 and 2000 kg / m3, preferably between 1400 and 1900 kg / m3, and more preferably between 1400 and 1700 kg / m3. At least one reinforcing layer may comprise natural fibers, such as jute. The reinforcing layer comprising natural fibers, such as but not limited to jute, can increase the setting time and the water consistency standard value of the composite layer.Furthermore, the hydration kinetics of magnesia cement could be slowed down when a reinforcing layer comprising natural fibers is embedded in the magnesia cement. This knowledge can be used to control the setting time, or curing time, of the panel. Therefore, the use of a reinforcing layer comprising natural fibers can ensure that the hardening of the panel is slowed down, thereby preventing the drying process from being too rapid, which results in water evaporation. The latter can cause unwanted irregularities in the material, such as cracks. At least one reinforcing layer may comprise synthetic fibers, in particular polymeric fibers, such as nylon fibers. Preferably, the composite layer comprises at least 50% by weight, preferably between 50 and 90% by weight, of magnesia cement. Preferably, the composite layer comprises between 1 and 15% by weight of cellulose-based fibers. Preferably, the composite layer comprises between 0 and 3% by weight of perlite. Preferably, the composite layer comprises between 1 and 8% by weight of reinforcing layer. In a preferred embodiment, at least one composite layer has a density greater than 1 kg / m3. This relatively high density will typically result in strong and rigid panels. However, it is also conceivable that at least one composite layer has a density of less than 1 kg / m3, which leads to savings in weight and therefore in transportation and handling costs. The lower density can be achieved, for example, by applying one or more foamed ingredients, such as expanded perlite, expanded polystyrene, etc. It is conceivable that the core is provided with a waterproof coating that substantially covers at least one composite layer. This can further improve the waterproof properties of the panel itself. To this end, the waterproof coating can be a two-component liquid-applied waterproofing formulation for application as a liquid to at least one (outer surface of at least one) composite layer.Typically, this coating comprises: separate components A and B which can be shipped in separate containers and can be combined to form a mixture in which vulcanization is initiated which solidifies the components into a membrane wherein component A comprises an aqueous latex of natural rubber or synthetic rubber and component B comprises a petroleum carrier wherein a vulcanizing agent operative to cure the rubber in component A is dispersed, and a hygroscopic agent operative to chemically bind water in component A. Component A preferably comprises a latex stabilizer operative to increase latex pot life which controls the initial pH of the latex components. It is also discovered that additions of potassium hydroxide (KOH) dissolved in trace amounts in component A can lengthen the setting time, but excessive amounts can destabilize and cause premature gelation of the latex.Thus, a preferred addition rate is up to 1.5 parts per 100 parts of rubber. It is believed that other high pH additives, such as ammonia or sodium hydroxide 13 (NaOH), may be used. Accordingly, an exemplary component A of the invention may comprise from 0 to 2.5 phr (per hundred parts of rubber). Component B contains, among other things, a petroleum carrier fluid 12 for the vulcanizing agent and the hygroscopic agent. In preferred embodiments, the petroleum carrier fluid is a mixture of hydrocarbon petroleums, such as a mixture of aromatic and paraffinic compositions. Aromatic petroleums which preferentially swell rubber particles are generally more viscous. Fluidity can be controlled by the addition of lower viscosity paraffinic petroleums which also serve to adjust the set time of the composition.In other illustrative embodiments, synthetic liquid plasticizers such as phthalates, adipates, or other commonly used rubber plasticizers may be used. The carrier fluid 12 may also contain a proportion of bitumen, either oxidized or penetration grade. The level of aromatic petroleum is unlikely to be less than 50% of the petroleum carrier fluid, and bitumen is unlikely to exceed 30%. However, the presence of bitumen is not critical to the invention. The use of a synthetic or natural hard resin is also optional. The petroleum carrier fluid 12 will comprise 20-60% by total weight of the formulation (when components A and B are combined). Component B typically contains a vulcanizing agent or gasket.Preferably, the vulcanizing pack comprises elemental sulfur as a sulfur donor for the system, zinc oxide as a vulcanization activator, and a mixture of zinc isopropyl xanthate (ZIX) and zinc dibutyl dithiocarbamate dibutylamine complex (ZDBCX) as accelerators. These may be used in the preferred ranges, respectively, 0.5 to 15.0 phr (parts of sulfur based on one hundred parts of rubber), 0.5 to 20.0 phr (ZnO), 0.1 to 5.0 phr (ZIX), and 0.1 to 5.0 phr (ZDBCX). Other known vulcanizing agents and / or packages are believed to be suitable for use in the invention. Component B may further comprise a hygroscopic agent or desiccant for chemically binding water from component A. The preferred hygroscopic agent is calcium oxide. Other hygroscopic agents may include other metal oxides that react with water to form hydroxides, for example, magnesium, barium, etc.Hydraulic cements, such as Portland cement or high alumina cement, calcium sulfate cement (plaster of Paris), or magnesium oxychloride cement, may also be used. The hygroscopic agent may also comprise anhydrous salts that absorb significant proportions (25% or more) of their own weight in water, such as borax. The weight of the hygroscopic agent is chosen to effectively dehydrate the latex, preferably with a slight excess to ensure water binding. However, partial desiccation of the latex, i.e., less than stoichiometric amounts of hygroscopic agent used, may be used. The hygroscopic agent, depending on which 14 bi cban / i ζηζ / α / γίΛA is chosen, may comprise 10-50% of the total formulation system. Component B may also comprise one or more rheology modifiers.Preferably, a combination of montmorillonite clay (activated with a chemical activator) and stearate-coated calcium carbonate is used to achieve the desired balance of rheological properties, although other options could be employed, such as organically treated bentonite clays, fumed silica, polymer fibers, ground rubber, pulverized fly ash, hollow glass microspheres, and hydrogenated castor oils. The amount of rheology modifiers, depending on the material chosen, could comprise 0.5 to 25.0% by weight of total solids in the formulation system (components A and B combined). It is also conceivable that a waterproof layer may be located between the core and the upper structure. This may further improve the waterproof properties of the panel itself. The waterproof layer may have the same composition as the waterproof coating composition described above, but may also be formed by a polymer layer, such as a PVC layer. It is not unlikely that the composite layer comprises a plurality of reinforcing layers. For example, at least a first reinforcing layer may be located in an upper portion of the composite layer, and at least a second reinforcing layer may be located in a lower portion of the composite layer. It is conceivable that the core comprises a laminate of composite layers, which are stacked directly and / or indirectly on top of one another. The composite layers may have identical compositions, although they may also have different compositions, allowing the properties of each composite layer to be modified and tailored to its primary function (e.g., sound dampening, strength, flexibility, etc.). The top structure is preferably bonded to the core using a waterproof adhesive. This protects the composite layer(s) from water applied to the top structure, making the panel more waterproof. It also prevents the top structure from easily separating from the core. The top structure preferably comprises at least one decorative layer and at least one transparent wear layer covering said decorative layer. A layer of lacquer or other protective layer may be applied on top of said wear layer. A topcoat may be applied between the decorative layer and the wear layer. The decorative layer will be visible and will be used to give the panel an attractive appearance. To this end, the decorative layer may have a design pattern, which may be, for example, a wood grain design, a mineral vein design resembling marble, granite, or any other natural stone vein, or a color pattern, a color mixture, or a single color, to name just a few design possibilities. Customized appearances, often achieved by digital printing during the panel production process, can also be imagined.The decorative upper structure can also be formed from a single layer. The decorative upper structure preferably comprises a polymer film and / or a paper layer. The aforementioned polymer film and paper layer are typically provided with a decorative print. The aforementioned polymer film and / or paper layer are bonded directly or indirectly to the core, for example by using glue. In an alternative embodiment, the decorative upper structure is omitted and therefore not applied to the panel according to the invention.In this latter embodiment, the decorative panel, in particular a floor panel, ceiling panel or wall panel, comprises: a core provided with an upper side and a lower side, a first panel edge comprising a first coupling profile and a second panel edge comprising a second coupling profile that is designed to interlock with said first coupling profile of an adjacent panel, both in the horizontal direction and in the vertical direction, wherein said core comprises: at least one composite layer comprising: at least one magnesia cement, cellulose-based particles dispersed in said magnesia cement; and at least one reinforcing layer embedded in said composite layer. Preferably, the panel comprises a backing layer bonded to a rear side of the core. Preferably, at least one backing layer is made at least partially of a flexible material, preferably an elastomer. The thickness of the backing layer typically ranges from about 0.1 to 2.5 mm. Non-limiting examples of materials from which the backing layer can be made are polyethylene, cork, polyurethane, and ethylene-vinyl acetate. The thickness of a polyethylene backing layer is, for example, typically 2 mm or less. The backing layer commonly provides additional strength, dimensional stability, and / or impact resistance to the panel itself, which increases the durability of the panel. Furthermore, the (flexible) backing layer can increase the acoustic (sound-dampening) properties of the panel. In a particular embodiment, Preferably, at least one reinforcing layer extends in only one coupling profile of the first and second coupling profiles. This can be achieved by designing the first coupling profile and the second coupling profile in such a way that a vertically extending (foldable) tongue-and-groove connection is formed, typically by using an upper and a lower profile 16, a preferred example of which will be given below. The advantage of applying the reinforcing layer in only one coupling profile, typically the aforementioned lower profile, and therefore not in the complementary coupling profile, the typically aforementioned upper profile, is that the flexibility of one profile (upper profile) is greater than the flexibility of the other profile (lower profile).This typically means that the upper profile is easier to deform than the lower profile, and this is particularly advantageous in case deformation is needed to make a coupling between the coupling profiles. Preferably, the first coupling profile comprises: • an upward tab, • at least one upward flank lying at a distance from the upward tab, • an upward groove formed between the upward tab and the upward flank wherein the upward groove is adapted to receive at least a portion of a downward tab of a second engaging profile of an adjacent panel, and • at least one first locking element, preferably provided on a side distant from the upward tab facing away from the upward flank, and preferably the second (complementary) engaging profile comprising: • a first downward tab, • at least one first downward flank located at a distance from the downward tab, • a first downward slot formed between the downward tab and the downward flank, wherein the downward slot is adapted to receive at least a part of an upward tab of a first coupling profile of an adjacent panel, and • at least one second locking element adapted to cooperate with a first locking element of an adjacent panel, said second locking element preferably being provided on the downward flank. Preferably, the first locking element comprises a bulge and / or a cavity, and wherein the second locking element comprises a bulge and / or a cavity. The protrusion is commonly adapted to be received at least partially in the cavity of an adjacent coupled panel in order to achieve a locked coupling, preferably a vertically locked coupling. It is also conceivable that the first locking element and the second lock are not formed by a bulge-cavity combination, but by another combination of co-acting profiled surfaces and / or high-friction contact surfaces.In this latter embodiment, at least one locking element of the first locking element and the second locking element may be formed by a contact surface (flat or otherwise formed) composed of a plastic material, optionally separate, configured to generate friction with the other locking element of another panel in the mated (engaged) condition. Examples of suitable plastics for generating friction include: Acetal (POM), which is rigid and strong with good creep resistance. It has a low coefficient of friction, remains stable at high temperatures, and offers good resistance to hot water; Nylon (PA), which absorbs more moisture than most polymers, improves impact resistance and overall energy absorption qualities as moisture is absorbed. Nylons also have a low coefficient of friction, good electrical properties, and good chemical resistance; Polyphthalamide (PPA). This high-performance nylon has improved temperature resistance and lower moisture absorption. It also has good chemical resistance; Polyetheretherketone (PEEK), which is a high-temperature thermoplastic with good chemical and fire resistance combined with high strength. PEEK is a favorite in the aerospace industry; Polyphenylene sulfide (PPS), which offers a balance of properties including chemical and high temperature resistance, flame retardancy, fluidity, dimensional stability and good electrical properties; Polybutylene terephthalate (PBT), which is dimensionally stable and has high thermal and chemical resistance with good electrical properties; Thermoplastic polyamide (TPI) is inherently flame retardant with good physical, chemical and wear resistance properties. Polycarbonate (PC), which has good impact resistance, high heat resistance, and good dimensional stability. PC also has good electrical properties and is stable in water and mineral or organic acids; and Polyvinyl chloride (PEI), which maintains strength and rigidity at elevated temperatures. It also has good long-term heat resistance, dimensional stability, inherent flame retardancy, and resistance to hydrocarbons, alcohols, and halogenated solvents. It is conceivable that the first coupling profile and the second coupling profile are designed such that in the coupled state there is a bias which forces the coupled panels at the respective edges towards each other, where this is preferably done by applying overlapping contours of the first coupling profile and the second coupling profile, in particular overlapping contours of the tongue downwards and the groove upwards and / or overlapping contours of the tongue upwards and the groove downwards, and where the first coupling profile and the second coupling profile are designed such that the two of said panels can be coupled to each other by means of a folding movement and / or a vertical movement, so that, in the coupled condition, where, in the coupled condition,at least a portion of the downward-facing tongue of the second coupling portion is inserted into the upward-facing groove of the first coupling portion, such that the downward-facing tongue is held by the first coupling portion and / or the upward-facing tongue is held by the second coupling portion. In a preferred embodiment, the panel comprises at least one third coupling profile and at least one fourth coupling profile located respectively at a third panel edge and a fourth panel edge, wherein the third coupling profile comprises: • a side tab extending in a direction substantially parallel to the upper side of the core, • at least one second downward flank located at a distance from the side tab, and • a second downward groove formed between the side tab and the second downward flank, wherein the fourth coupling profile comprises: • a third slot configured to accommodate at least a portion of the side tab of the third coupling profile of an adjacent panel, said third slot being defined by an upper flange and a lower flange, said lower flange being provided with an upward locking element, wherein the third coupling profile and the fourth coupling profile are configured such that two of said panels can be coupled to each other by means of a turning movement, wherein, in the coupled state: at least a portion of the side tab of a first panel is inserted into the third slot of an adjacent second panel, and wherein at least a portion of the upward locking element of said second panel is inserted into the second downward slot of said first panel. The panel, typically the core, in particular at least one composite layer, preferably comprises recycled material. Recycled material typically relates to the reuse of surplus material resulting from previous production processes (panels). The core preferably has a thickness of at least 3 mm, preferably at least 4 mm, and most preferably at least 5 mm. The panel thickness is typically between 3 and 10 mm, preferably between 4 and 8 mm. The invention also relates to a decorative covering, in particular a decorative floor covering, a decorative ceiling covering, or a decorative wall covering, comprising a plurality of decorative panels coupled together according to the invention. The covering can also be installed on vertical corners, such as the inside corners of intersecting walls or furniture, and on outside corners, such as at entrances.The invention also relates to a decorative panel, in particular a floor panel, ceiling panel or wall panel, comprising a core provided with an upper side and a lower side, a decorative upper structure fixed to said upper side of the core, a first panel edge comprising a first coupling profile, and a second panel edge comprising a second coupling profile which is designed to interlock with said first coupling profile of an adjacent panel, both in the horizontal direction and in the vertical direction, wherein said core comprises at least one composite layer comprising at least one magnesia cement, cellulose-based particles dispersed in said magnesia cement; and at least one reinforcing layer embedded in said composite layer, wherein the magnesia cement is based on magnesium oxide and wherein the composite layer comprises citric acid.In this preferred embodiment, the magnesia cement is based on magnesium oxide, and the composite layer also comprises citric acid. The combination of magnesium oxide and citric acid has a positive effect on the crystal structure and its formation of the composite layer. The combination of magnesium oxide and citric acid, in particular, facilitates the formation of needle-like structures. This combination can therefore contribute to improving the compressive strength and water resistance of the composite layer and, therefore, of the panel as a whole. Furthermore, the use of citric acid can improve the volume stability of the composite layer. The invention is clarified by the following non-limiting clauses: 1. Decorative panel, in particular floor panel, ceiling panel or wall panel, comprising: a core provided with an upper side and a lower side, a decorative upper structure fixed on said upper side of the core, a first panel edge comprising a first coupling profile, and a second panel edge comprising a second coupling profile which is designed to interlock with said first coupling profile of an adjacent panel, both in horizontal direction and in vertical direction, bi cban / i ζηζ / α / γίΛA wherein said core comprises: • at least one composite layer comprising: • at least one magnesia layer comprising magnesium oxide and / or magnesium oxide and / or magnesia cement, • particles, in particular cellulose-based particles, dispersed in said magnesia layer; and • preferably at least one reinforcing layer embedded in said composite layer. 2. Panel according to clause 1, wherein the magnesia layer is based on magnesium oxide and / or magnesium hydroxide. 3. Panel according to one of the preceding clauses, wherein the magnesia layer as such is free of magnesium oxide. 4. Panel according to one of the preceding clauses, wherein the magnesia layer as such comprises magnesium hydroxide. 5. Panel according to one of the preceding clauses, wherein the magnesia layer comprises water, in particular hydrated water. 6. Panel according to one of the clauses comprises magnesium chloride. 7. Panel according to one of the clauses comprises magnesium oxide. 8. Panel according to one of the preceding clauses, wherein the above magnesia layer, wherein the above magnesia layer, wherein the magnesia layer comprises 5Mg(OH)2MgCl2-8H2O. 9. Panel according to one of the preceding clauses, wherein the magnesia layer comprises Mg2(OH)ClCO3'3H2O. 10. Panel according to one of the preceding clauses, wherein the magnesia layer comprises magnesite, in particular hydromagnesite (Mg5(CO3)4(OH)2-4H2O). 11. Panel according to one of the previous clauses, wherein the magnesia layer is based on monoammonium dihydrogen phosphate (NH4H2PO4). 12. Panel according to one of the previous clauses, wherein the magnesia layer comprises struvite (NFLMgPO^óHaO) and / or dittmarite (NH4MgPO4*H2O). 13. Panel according to one of the preceding clauses, wherein the magnesia layer comprises MgHPCU 14. Panel according to one of the previous clauses, wherein the magnesia layer is based on monopotassium phosphate (KH2PO4). 15. Panel according to one of the preceding clauses, wherein the magnesia layer comprises magnesium potassium phosphate hexahydrate (MgKPO4*6H2O). 16. Panel according to one of the preceding clauses, wherein the magnesia layer comprises at least one borate. 17. Panel according to one of the preceding clauses, wherein the magnesia layer is based on magnesium sulfate, in particular, epsomite mineral sulfate heptahydrate (MgSO4-7H2O). 18. Panel according to one of the preceding clauses, wherein the magnesia layer comprises 5Mg(OH)2*MgSO4*3H2O (phase 513) and / or 3Mg(OH)2«MgSO4*8H2O (phase 318). 19. Panel according to one of the preceding clauses, wherein the magnesia layer comprises 5Mg(OH)2«MgSO4*5H2O (phase 515) and / or Mg(OH)2*MgSO4«7H2O (phase 517). 20. Panel according to one of the preceding clauses, wherein the composite layer comprises citric acid. 21. Panel according to one of the preceding clauses, wherein the composite layer comprises sodium silicate. 22. Panel according to one of the preceding clauses, wherein the composite layer comprises sodium bicarbonate. 23. Panel according to one of the preceding clauses, wherein the composite layer comprises dolomite. 24. Panel according to one of the preceding clauses, wherein the composite layer comprises phosphoric acid (H3PO4) and / or at least one phosphate, in particular H2PO4'. 25. Panel according to one of the preceding clauses, wherein the composite layer comprises at least one mineralizer selected from the group consisting of: sodium hydroxide (NaOH), calcium chloride (CaCh), aluminum sulfate (AhCSCLh) and calcium hydroxide Ca(OH)2. 26. Panel according to one of the preceding clauses, wherein the cellulose-based particles comprise lignocellulose. 27. Panel according to one of the preceding clauses, wherein the cellulose-based particles comprise wood. 28. Panel according to one of the preceding clauses, wherein at least a part of the cellulose-based particles is formed by fibers. 29. Panel according to one of the preceding clauses, wherein the cellulose-based particles comprise hemp fibers. 30. Panel according to one of the preceding clauses, wherein at least a part of the cellulose-based particles is formed by powder. 31. Panel according to one of the preceding clauses, wherein at least a part of the cellulose-based particles is formed by wood chips. 32. Panel according to one of the preceding clauses, wherein at least a part of the cellulose-based particles is formed by wool, in particular wood wool. 33. Panel according to one of the preceding clauses, wherein at least a part of the cellulose-based particles is formed by wood chips. 34. Panel according to one of the preceding clauses, wherein the core comprises dispersed particles that are made of a material other than cellulose. 35. Panel according to one of the preceding clauses, wherein the composite layer comprises at least one additional filler selected from the group consisting of: steel, glass, polypropylene, wood, acrylic, alumina, curaua, carbon, cellulose, coconut, Kevlar, nylon, perlon, polyethylene, PVA, rock wool, sisal and fique. 36. Panel according to one of the preceding clauses, wherein the composite layer comprises sodium carboxymethylcellulose. 37. Panel according to one of the preceding clauses, wherein the composite layer comprises fly ash. 38. Panel according to one of the preceding clauses, wherein the composite layer comprises silica fume. 39. Panel according to one of the preceding clauses, wherein the composite layer comprises iron oxide. 40. Panel according to one of the preceding clauses, wherein the composite layer comprises fatty acids. 41. Panel according to one of the preceding clauses, wherein the composite layer comprises alkali metal sulfates. 42. Panel according to one of the preceding clauses, wherein at least one composite layer comprises at least one polymer, such as PVC or PUR. 43. Panel according to one of the preceding clauses, wherein at least one composite layer is free of polymers. 44. Panel according to one of the preceding clauses, wherein the composite layer comprises perlite, preferably expanded perlite. 45. Panel according to one of the preceding clauses, wherein the composite layer comprises at least one flame-retardant additive. 46. ​​Panel according to one of the preceding clauses, wherein the composite layer is at least partially foamed. 47. Panel according to one of the preceding clauses, wherein the composite layer is free of plasticizer. 48. Panel according to one of the preceding clauses, wherein the reinforcing layer is a non-woven layer or a woven layer, in particular a fabric. 49. Panel according to one of the preceding clauses, wherein the reinforcing layer comprises fiberglass. 50. Panel according to one of the preceding clauses, wherein the reinforcing layer comprises natural fibers, such as jute. 51. Panel according to one of the preceding clauses, wherein the reinforcing layer comprises synthetic fibers, in particular polymeric fibers. 52. Panel according to one of the preceding clauses, wherein the composite layer comprises at least 50% by weight, preferably between 50 and 90% by weight, of magnesia layer. 53. Panel according to one of the preceding clauses, wherein the composite layer comprises between 1 and 15% by weight of cellulose-based fibers. 54. Panel according to one of the preceding clauses, wherein the composite layer comprises between 0 and 3% by weight of perlite. bi cban / i ζηζ / α / γίΛΐ 55. Panel according to one of the preceding clauses, wherein the composite layer comprises between 1 and 8% by weight of reinforcement layer. 56. Panel according to one of the preceding clauses, wherein at least one composite layer has a density greater than 1 kg / m3. 57. Panel according to one of the preceding clauses, wherein at least one composite layer has a density less than 1 kg / m3. 58. Panel according to one of the preceding clauses, wherein the core is provided with a waterproof coating substantially covering at least one composite layer. 59. Panel according to one of the previous clauses, wherein a waterproof layer is placed between the core and the upper structure. 60. Panel according to one of the preceding clauses, wherein the composite layer comprises a plurality of layers of the reinforcement layer, wherein, preferably, at least a first reinforcement layer is located in an upper portion of the composite layer, and wherein at least a second reinforcement layer is located in a lower portion of the composite layer. 61. Panel according to one of the preceding clauses, wherein the core comprises a laminate of composite layers, which are stacked directly and / or indirectly with each other. 62. Panel according to one of the preceding clauses, wherein the core comprises a laminate of composite layers, wherein the composition of at least two composite layers is mutually different. 63. Panel according to one of the preceding clauses, wherein the upper structure is adhered to the core by means of a waterproof adhesive. 64. Panel according to one of the preceding clauses, wherein the upper structure comprises at least one decorative layer and at least one transparent wear layer covering said decorative layer. 65. Panel according to clause 64, wherein the wear layer has a melting temperature greater than 100 degrees Celsius, wherein the wear layer is preferably made of polyurethane. 66. Panel according to one of the preceding clauses, wherein the panel comprises a backing layer bonded to a rear side of the core. 67. Panel according to one of the preceding clauses, wherein at least one reinforcing layer extends in a single coupling profile of the first and second coupling profiles. 68. Panel according to one of the preceding clauses, wherein the panel, preferably the core, comprises recycled material. 69. Panel according to one of the previous clauses, where the thickness of the panel is between 3 and 10 mm. 70. Panel according to one of the preceding clauses, wherein the first coupling profile comprises: • an upward tab, • at least one upward flank located at a distance from the upward tab, • a first upward slot formed between the upward tab and the upward flank wherein the upward slot is adapted to receive at least a part of a downward tab of a second coupling profile of an adjacent panel, and • at least one first locking element, preferably provided on a side distant from the upward tab facing away from the upward flank, and wherein the second coupling profile comprises: • a first downward tab, • at least one first downward flank located at a distance from the downward tab, • a first downward slot formed between the downward tab and the downward flank, wherein the downward slot is adapted to receive at least a part of an upward tab of a first coupling profile of an adjacent panel, and • at least one second locking element adapted to cooperate with a first locking element of an adjacent panel, said second locking element preferably providing on the downward flank. 71. Panel according to any of the preceding clauses, wherein the panel comprises at least a third coupling profile and at least a fourth coupling profile located respectively at a third panel edge and a fourth panel edge, wherein the third coupling profile comprises: • a side tab extending in a direction substantially parallel to the upper side of the core, • at least one second downward flank located at a distance from the side tab, and • a second downward groove formed between the side tab and the second downward flank, wherein the fourth coupling profile comprises: • a third slot configured to accommodate at least a portion of the side tongue of the third coupling profile of an adjacent panel, said third slot being defined by an upper flange and a lower flange, said lower flange being provided with an upward locking element, wherein the third coupling profile and the fourth coupling profile are configured such that two of said panels can be coupled to each other by means of a turning movement, wherein, in the coupled state: at least a portion of the side tongue of a first panel is inserted into the third slot of an adjacent second panel, and wherein at least a portion of the upward locking element of said second panel is inserted into the second downward slot of said first panel. 72. Decorative covering, in particular a decorative floor covering, decorative ceiling covering or decorative wall covering, comprising a plurality of decorative panels coupled together according to any of clauses 1-71. The ordinal numbers used in this document, such as "first," "second," and "third," are for identification purposes only. Therefore, the use of the terms "third blocking element" and "second blocking element" does not necessarily require the co-presence of a "first blocking element." The decorative panels according to the invention can also be referred to as decorative tiles. Complementary coupling profiles mean that these coupling profiles can cooperate with each other. However, for this purpose, the complementary coupling profiles do not necessarily have to have complementary shapes. Locking in the vertical direction means locking in a direction perpendicular to the plane of the panel. Locking in the horizontal direction means locking in a direction perpendicular to the respective coupled edges of two panels and parallel to or adjacent to the plane defined by the panels. The invention will be clarified on the basis of non-limiting illustrative embodiments shown in the following figures, where: • The Figure shows a schematic representation of a multipurpose panel for use in a multipurpose panel system according to the invention; bl CbQn / l 7Π7 / 3 / ΥΙΛΙ • Figure Ib shows a schematic representation of a multipurpose panel system comprising a plurality of multipurpose panels as shown in Figure la; • Figure 2a shows a schematic representation of two different types of multipurpose panels for use in another embodiment of a multipurpose panel system according to the invention; • Figure 2b shows a schematic representation of a multi-purpose panel system comprising a plurality of multi-purpose panels as shown in Figure 2a; • Figure 3 a shows a schematic representation of a multi-purpose panel for use in yet another embodiment of a multi-purpose panel system according to the invention; • Figure 3b shows a schematic representation of a multi-purpose panel system comprising a plurality of multi-purpose panels as shown in Figure 3a; • Figure 4a shows a cross section along line AA of a multipurpose panel as shown in Figures 1a, 2a or 3a; • Figure 4b shows a cross section along line BB of a multipurpose panel as shown in Figures 1a, 2a or 3a; • Figures 5a-5c show a cross-section of two multipurpose panels as shown in Figures 1a, 2a or 3a in a first, second and third coupled condition respectively; • Figures 6a-6c show a cross-section of two multi-purpose panels with alternative coupling profiles in a first, second, and third coupled condition, respectively; and • Figures 7a-7c show a cross-section of two multi-purpose panels with other alternative coupling profiles in a first, second, and third coupled condition, respectively. Figure 1 shows a schematic representation of a multi-purpose decorative panel (100) for use in a multi-purpose panel system (110) according to the invention. Figure 1 shows a panel (100) comprising a first pair of opposing edges consisting of a first edge (101) and a third opposing edge (103) and a second pair of opposing edges consisting of a second edge (102) and a (further) third opposing edge (103). The first, second and third edges (101, 102, 103) are respectively provided with first, second and third coupling profiles (104, 105, 106). The first coupling profile (104) and the third coupling profile (106) are configured such that two of said panels (100) can be coupled to each other at the first and third edges (101, 103) by means of a rotating movement.Furthermore, the second coupling profile (105) and the third coupling profile (106) are configured such that the two of said panels (100) can be coupled to each other at the second and third edges (102, 103) by means of a folding movement and / or a vertical movement. The proportional relationship between the width and the length of the panel (100) can be chosen at will. The Figure shows only one of the many possibilities where the panel has an upper side (107) with a rectangular contour (108). However, it is also possible that the width and the length of the panel (100) are the same, so that the panel (100) has an upper side (107) with a square contour. Figure 1b shows a schematic representation of a multi-purpose panel system (110) comprising a plurality of multi-purpose panels (100) as shown in Figure 1a. Although each of the panels (100) are equivalent, having a first pair of opposing edges consisting of a first edge (101) and a third opposing edge (103) and a second pair of opposing edges consisting of a second edge (102) and a third opposing edge (103), the panels (100) may, due to the compatibility of the mating profile of the third edge (103) with the mating profile of the first and second edges (101,102), be joined in different ways, resulting in differential panel patterns (111,112) within a multi-purpose panel system (110).In the depicted multi-purpose panel system (110) wherein the individual panels (110) have a top side (107) with a rectangular outline (108), the panels (100) each have a long side (113) and a short side (114). The different panel patterns (111, 112) are created by coupling a first panel pattern (111) of interconnected panels (100), having their long side (113) connected to the long side (113) of an adjacent panel (100), to a second panel pattern (112) of interconnected panels (100), having their long side (113) connected to the long side (113) of an adjacent panel (100) and their short side (114) connected to the short side (114) of another adjacent panel (100).The first and second panel patterns (111, 112) are rotated relative to each other such that the long sides (113) of the panels (100) of the first panel pattern (111) lie at an angle of 90 degrees relative to the long sides (113) of the panels (100) of the second panel pattern (112). This coupling between the different panel patterns (111, 112) is made possible by connecting the short sides (114) of the panels (100) of the first panel pattern (111) to the long sides (113) of the panels (100) of the second panel pattern (112). The installation of the 29 bi cban / i ζηζ / α / γίΛΐ panel system (110) can be performed by tilting downwards the first edge (101) of a panel (100) to be installed with respect to a third edge (103) of an already installed panel (100), which will commonly mutually block said panels (100) in both vertical and horizontal directions.During this angulation or rotation movement of the panel (100) to be installed with respect to the already installed panel (100), the second edge (102) of the panel (100) to be installed will be connected (simultaneously) to the third edge (103) of another already installed panel (100), which is typically performed by lowering or folding the panel (100) to be installed with respect to another already installed panel (100) during which the second edge (102) of the panel (100) to be installed and the third edge (103) of the other already installed panel (100) will divide from each other. This results in a locking of the panel (100) to be installed with respect to another already installed panel (100) both in horizontal direction and in vertical direction. Figure 2a shows a schematic representation of two different types of multi-purpose panels (201, 202) for use in another embodiment of a multi-purpose panel system (200) according to the invention. Like the multi-purpose panel (100) shown in Figure 1a, each of these panels (201, 202) comprises a first pair of opposing edges consisting of a first edge (101) and a third opposing edge (103) and a second pair of opposing edges consisting of a second edge (102) and a third opposing edge (103).Again, the first, second and third edges (101, 102, 103) are provided respectively with a first, second and third coupling profile (104, 105, 106), wherein the first coupling profile (104) and the third coupling profile (106) are configured such that two panels (201, 202) can be coupled to each other at the first and third edges (101, 103) by means of a turning movement, and the second coupling profile (105) and the third coupling profile (106) are configured such that the two panels (201, 202) can be coupled to each other at the second and third edges (102, 103) by means of a folding movement and / or a vertical movement.This time, however, there are two different types of panels (201, 202), wherein the coupling profiles (105, 106) of one pair of opposite edges (102, 103) in the first type of panel (201) are arranged in a mirror-inverted manner relative to the coupling profiles (105, 106) of the corresponding pair of opposite edges (102, 103) in the second type of panel (202). Note that the depicted pairs of edges of the different types of panels (201, 202) that are mirror-inverted are formed by a second and a third edge (102, 103). However, it is equally possible for the mirror-inverted pairs of edges to be formed by a first and a third edge (101, 103). Furthermore, the multipurpose panels (201, 202) for use in this multipurpose panel system (200) have an upper side (107) with a parallelogram-shaped contour (208).Two adjacent edges (101, 102, 103) of these panels (201, 202) enclose an acute angle (203) or an obtuse angle (204). In this specific embodiment, the first and second edges (101, 102) respectively, the third edge (103) enclose an obtuse angle (204) of the same size, while the first and third edges (101, 103) respectively, the second and third edges (102, 103) enclose an acute angle (203) of the same size. The difference in panel configuration and the parallelogram-shaped contour (208) of its upper side (107) allow these panels (201, 202) to form a chevron pattern (205) in a joined state. Figure 2b shows a schematic representation of a multi-purpose panel system (200) comprising a plurality of multi-purpose panels (201, 202) as shown in Figure 2a. As previously discussed, the multi-purpose panels (201, 202) that are part of this multi-purpose panel system (200) come in two different types / configurations (reflected).While the difference in panel configuration and the parallelogram shape of its upper surface (107) allows these panels (201, 202) to form a Chevron pattern (205) in a joined state, having a first pair of opposing edges consisting of a first edge (101) and a third opposing edge (103) and a second pair of opposing edges consisting of a second edge (102) and a third opposing edge (103), where the mating profile (106) of the third edge (103) is compatible with the mating profile (104, 105) of both the first and second edges (101, 102), it allows the panels (201, 202) to be joined also in different ways, which results in differential patterns of panels (206, 207) within an interconnected multipurpose panel system (200).As in the multi-purpose panel system (110) shown in Figure 1 b, the different panel patterns (206, 207) are created by coupling a first panel pattern (206) of interconnected panels (201, 202) to a second panel pattern (207) of interconnected panels (201, 202). Within these separate panel patterns (206, 207), each panel (201, 202) has each of its pairs of opposite edges (101, 103; 102, 103) connected to edges (101, 102, 103) of adjacent panels (201, 202) that are part of a corresponding pair of opposite edges (101, 103; 102, 103) of said adjacent panels (201, 202).However, the coupling of the first and second panel patterns (206, 207) is accomplished by connecting a panel (201, 202) of the first panel pattern (206) with an edge (101, 103) that is part of one pair of opposing edge elements (101, 103) to a panel (201, 202) of the second panel pattern (207) with an edge (102, 103) that is part of the other, non-corresponding pair of opposing edges (102, 103). The result is an interconnected multipurpose panel system (200) comprising two different panel patterns (206, 207) that are rotated 90 degrees relative to each other. The installation of the panel system (200) shown in Figure 2b is typically analogous to the installation of the panel system (110) shown in Figure 1b. Figure 3a shows a schematic representation of a multipurpose panel (301) for use in yet another embodiment of a multipurpose panel system (300) according to the invention. Apart from the multipurpose panels (100, 201, 202) shown in Figures 1a and 2a, each of these panels (301) comprises three pairs of opposite edges and has a top side (107) with a regular hexagon-shaped contour (302). The first pair of opposite edges consists of a first edge (101) and a third opposite edge (103). The second and third pairs of opposite edges consist of a second edge (102) and a third opposite edge (103). The first, second and third edges (101, 102, 103) are positioned here such that the third edges (103) are directly adjacent to each other and the second edges (102) are located on both edges adjacent to the first edge (101). The second edges (102) are consequently not adjacent to each other.The similarity between these multipurpose panels (301) and the multipurpose panels (100, 201, 202) shown in Figures 1a and 2a is, however, that the first, second and third edges (101, 102, 103) are respectively provided with a first, second and third coupling profile (104, 105, 106), wherein the first coupling profile (104) and the third coupling profile (106) are configured such that two panels (301) can be coupled to each other at the first and third edges (101, 103) by means of a turning movement, and the second coupling profile (105) and the third coupling profile (106) are configured such that the two panels (301) can be coupled to each other at the second and third edges (102, 103) by means of a folding movement and / or a vertical movement. Figure 3b shows a schematic representation of a multi-purpose panel system (300) comprising a plurality of multi-purpose panels (301) as shown in Figure 3a. In the depicted panel formation, the panels (301) are all oriented identically. Installation of the panel system (300) may be performed similarly to the panel systems (110, 200) of Figures 1b and 2b. By angling downwards a first edge (101) of a panel (301) to be installed relative to a third edge (103) of an already installed panel (301), said panels (301) will commonly lock together in both the vertical and horizontal directions.During this tilting or turning movement of the panel (301) to be installed with respect to the already installed panel (301), one or more second edges (102) of the panel (300) to be installed will be connected (simultaneously) to a third edge (103) of one or more adjacent panels (301) already installed, which is typically performed by lowering or folding the panel (301) to be installed with respect to another panel (301) already installed (301) during which said second edge (102) of the panel (301) to be installed and the third edge (103) of the other panel (301) already installed (301) will scissor-split relative to each other. This results in a locking of the panel (301) to be installed with respect to other already installed panel(s) (301) both in the horizontal direction and in the vertical direction. Figure 4a shows a cross-section along line AA of a multi-purpose panel (100, 201, 202, 301) as shown in Figures 1a, 2a or 3a. In Figure 4a, the first edge (101) and an opposite third edge (103) of the panel (100, 201, 202, 301) are visible, which has a first coupling profile (104) and a third coupling profile (106) respectively. The first coupling profile (104) comprises a side tab (400) extending in a direction substantially parallel to the upper side (107) of the panel (100, 201, 202, 301), having at least a first descending flank (401) at a distance from the side tab (400), and a first downward cavity (402) formed between the side tab (400) and the first downward flank (401).The near side (403) of the side tongue (400) of the first coupling profile (104), which faces the first recess downwards (402), slopes downwards in a direction away from the first downward flank (401). However, it is also possible for the near side (403) of the side tongue (400) to slope downwards in a direction towards the first downward flank (401). A first transition zone (404) can be defined between the near side (403) of the side tongue (400) of the first coupling profile (104) and a bottom side (405) of the side tongue (400) of the first coupling profile (104), which first transition zone (404) is curved in this case. The upper side (406) of the first downward cavity (402) is represented in the panel (100, 201,202, 301) inclined downwards towards the first downward flank (401).The first coupling profile (104) may further comprise a first locking element (407) which can, in a coupled position, cooperate with a third locking element (440) of a third coupling profile (106) of an adjacent panel (100, 201, 202, 301). This first locking element (407) may be provided on the first falling edge (401) of the first coupling profile (104). In the currently shown panel (100, 201, 202, 301), the first locking element (407) comprises at least one first locking groove (408). The third coupling profile (106) comprises a third cavity (430) configured to receive at least a part of the lateral tongue (400) of the first coupling profile (104) of a further panel (100, 201, 202, 301), said third cavity (430) being defined by an upper flange (431) and a lower flange (432), wherein said lower flange (432) is provided with an upward locking element (433). The near side (434) of the upward locking element (433) of the third coupling profile (106), facing the third cavity (430), is inclined upwardly in a direction away from the upper flange (431). However, alternatively, it may be possible for the near side (434) of the upward locking element (433) to be tilted upward in a direction towards the upper rim (431).A third transition zone (435) can be defined between the near side (434) of the upward locking element (433) and an upper side (436) of the upward locking element (433), which third transition zone (435) is in this instance also curved to follow the first curved transition zone (404). The upper side (436) of the upward locking element (433) is in the shown panel (100, 201, 202, 301) inclined downwards in a direction looking from the upper flange (431) of the third coupling profile (106). On the lower side (437) of the lower flange (432) of the third coupling profile (106), a recess (438) is present, which extends to the distal end (439) of the lower flange (432). This recess (438) allows the lower flange (432) to be bent in the downward direction.As already mentioned, the third coupling profile (106) may further comprise a third locking element (440) that can cooperate with the first locking element (407) of the first coupling profile (104) of an adjacent panel (100, 201, 202, 301) to establish a vertical lock between the coupled panels (100, 201, 202, 301). The third locking element (440) may be provided on a distal side (441) of the lower flange (432) remote from the third cavity (430) and / or on a distal side (442) of the upwardly facing locking element (433) facing away from the third cavity (430). The third locking element (440) may, as shown here, be specifically positioned at a distance from both a lower side (437) of the lower rim (432) and an upper side (436) of the upward locking element (433).In the presently shown panel, the third locking element (440) comprises at least one outward protrusion (443), the outward protrusion (443) being adapted to be received at least partially in the first locking groove (408) or a second locking groove (423) of an adjacent coupled panel (100, 201, 202, 301) so as to perform a (vertically) locked coupling. The core (452) is provided with at least one reinforcing layer (454), such as a fiberglass (fabric) layer, incorporated (embedded) in the core (452). More particularly, the core comprises at least one composite layer comprising at least one magnesia cement, cellulose-based particles dispersed in said magnesia cement; and at least one reinforcing layer (454) embedded in said composite layer.The composite layer shown can be considered as a single layer, although one part is located above the reinforcing layer (454) and one part is located below the reinforcing layer (454), where both parts are mutually connected (integrally) by the composite material present in the pores of the reinforcing layer. Examples of detailed compositions and additives are described exhaustively above. Figure 4b shows a cross-section along the line BB of a multi-purpose panel (100, 201, 202, 301) as shown in Figures 1a, 2a or 3a. In Figure 4b, the second edge (102) and another third opposite edge (103) of the panel (100, 201, 202, 301) are visible, having a second coupling profile (105) and a third coupling profile (106) respectively.Where the third coupling profile (106) coincides with the third coupling profile (106) provided on the third adjacent edge (103) of the panel (100, 201, 202, 301), the characteristics of which are given above in the description of the cross-section along the line AA of the multipurpose panel (100, 201, 202, 301), the second coupling profile (105) comprises a downward tongue (410) extending in a direction substantially perpendicular to the upper side (107) of the panel (100, 201, 202, 301), at least one second downward flank (411) located at a distance from the downward tongue (410), and a second downward cavity (412) formed between the downward tongue (410) and the second downward flank (411). The near side (413) of the downward tongue (410) of the second coupling profile (105), which faces the second downward cavity (412), slopes downward in a direction away from the second downward flank (411).However, it is also possible that the near side (413) of the downward tongue (410) slopes downwards in a direction towards the second downward flank (411). A second transition zone (414) can be defined between the near side (413) of the downward tongue (410) of the second coupling profile (105) and a bottom side (415) of the downward tongue (410) of the second coupling profile (105), which second transition zone (414) is curved in this case.A distal side (416) of the down-tab (410), remote from the second down-tab (412), comprises at least one up-standing top wall portion (417) adjacent the top side (107) of the panel (100, 201, 202, 301), and adjacent to and located downstream of said up-standing top wall portion (417), an angled wall portion (418) angled inwardly toward a chamfered and / or curved bottom wall portion (419) of said distal side (416) of the down-tab (410). An intermediate up-standing wall portion (420) may be present between the angled wall portion (418) and the chamfered and / or curved bottom wall portion (419). The lower wall portion (419) of the distal side (416) of the downward tab (410) may further be connected to the lower side (415) of the downward tab (410).The upper side (421) of the second downward cavity (412) is shown on the panel (100, 201, 202, 301) inclined downwards towards the second downward flank (411). The second coupling profile (105) may further comprise at least one second locking element (422) which can, in a coupled position, cooperate with a third locking element (440) of a third coupling profile (106) of an adjacent panel (100, 201, 202, 301) to establish a vertical locking between the panels (100, 201, 202, 301). The second locking element (422) may be provided on the second descending flank (411) of the second coupling profile (105).In the presently depicted panel (100,201,202,301), the second locking element (422) comprises at least one second locking slot (423) adapted to at least partially receive the outward protrusion (443) of the third locking element (440) of an adjacent coupled panel (100,201,202,301) in order to perform a (vertically) locked coupling. The coupling profiles (104, 105, 106) of each of the multipurpose panels (100, 201, 202, 301) shown in Figures 4a and 4b are provided with chamfers (bevels) (450) on or near the upper side (107) of the panels (100, 201, 202, 301). The panels (100, 201, 202, 301) comprise an upper substrate (451) fixed to an upper side (453) of a core (452) to which the first, second and third coupling profiles (104, 105, 106) are integrally connected. At least one reinforcing layer (454), such as a layer of fiberglass (fabric), embedded in the core (452), is again visualized. Both Figure 4a and Figure 4b show that this reinforcement layer (454) is present only in one of the two complementary coupling profiles.The upper substrate (451) comprises a decorative layer (455), an abrasion resistant wear layer (456) covering said decorative layer (455), and a transparent topcoat layer (457) positioned between the decorative layer (455) and the wear layer (456). The panels (100, 201, 202, 301) further comprise a backing layer (458) secured to one side of the bottom portion (459) of the core (452). Figures 5a-5c show a cross-section through two multipurpose panels (100, 201, 202, 301) as shown in Figures 1a, 2a or 3a in a first, second and third coupled condition respectively. In these figures it can be seen that in a coupled state, at least a part of the side tongue (400) of the first coupling profile (104) of one panel (100, 201, 202, 301) is inserted into the third cavity (430) of the third coupling profile (106) of an adjacent panel (100, 201, 202, 301), and at least a part of the upward locking element (433) of the third coupling profile (106) is inserted into the first downward cavity (402) of the first coupling profile (104).In order to establish a fixation in the mutual position of the first coupling profile (104) and the third coupling profile (106), a lower side (405) of the side tongue (400) of the first coupling profile (104) may be supported by a lower surface (500) of the third cavity (430) of the third coupling profile (106). The first edge (101) and the third edge (103), in coupled condition, define a first closing surface (501) defined as a first vertical plane (502) through the upper edges (503) of the coupled panels (100, 201, 202, 301). Each of the side tongue (400) and the third cavity (430) extend through said first vertical plane (502). In the embodiments shown, the first and third coupling profile (104, 106) respectively comprise a first and third locking element (407, 440).The first and third locking elements (407, 440) are positioned here such that the first locking element (407) faces and cooperates with the third locking element (440) of the third coupling profile (106) to realize a vertical locking effect. Figures 5a-5c further show that in coupled condition, at least a part of the downward tongue (410) of the second coupling profile (105) is inserted into the third cavity (430) of the third coupling profile (106), and at least a part of the upward locking element (433) of the third coupling profile (106) is inserted into the second downward cavity (412) of the second coupling profile (105).In order to establish a fixation in the mutual position of the second coupling profile (105) and the third coupling profile (106), a lower side (415) of the descending tongue (410) of the second coupling profile (105) can be supported by a lower surface (500) of the third cavity (430) of the third coupling profile (106). The second edge (102) and the third edge (103), in coupled condition, define a second closing surface (504) defining a second vertical plane (505) through the upper edges (503) of the coupled panels (100, 201, 202, 301). The descending tongue (410) is thus positioned on one side of said second vertical plane (505), while the third cavity (430) extends through said second vertical plane (505). In the embodiments shown, the second coupling profile (105) further comprises a second locking element (422).Said second locking element (422) faces and acts together with the third locking element (440) of the third coupling profile (106) to achieve a vertical locking effect. Figures 6a-6c show a cross-section of two multipurpose panels (600) with alternative coupling profiles (601, 602, 603) in a first, second and third coupled condition respectively. Wherein the coupling profiles (104, 105, 106) of the panels (100, 201, 202, 301) shown in Figures 5a-5c are configured such that in a coupled condition, there is (substantially) no pretension between the coupling profiles (104, 105, 106), the coupling profiles (601, 602, 603) of the panels (600) shown in Figures 6a-6c are configured such that in a coupled condition there is a pretension that forces the respective panels 37 bl CbQn / l 7P7 / 3 / YILI (600) at their respective edges (604) against each other. In the shown embodiments of the coupling profiles (601, 602, 603), the pretension is the result of a (local) deformation of the coupling profiles (601, 602, 603). Figures 7a-7c show a cross-section of two multipurpose panels (700) with alternative coupling profiles (701, 702, 703) in a first, second and third coupling condition, respectively. In this embodiment of the third coupling profile (703), there is no cavity on the lower side (705) of the lower flange (704) thereof. In the represented multipurpose panels (700), the first coupling profile (701) further comprises a further first locking element (706), provided on a distal side (707) of the first coupling profile (701), which is located above at least a part of the sideways tongue (708). Furthermore, the second coupling profile (702) comprises a further second locking element (709), provided on a distal side (711) of the downward tongue (710) facing away from the second downward cavity (712).The third coupling profile (703) further comprises a third locking element (713), provided on one side (715) of the upper flange (714). In the coupled conditions shown in Figures 7a and 7b, the third additional locking element (713) faces the distal side (707) of the first coupling profile (701) of the adjacent panel (700), while in the coupled condition shown in Figure 7c, the third additional locking element (713) faces the distal side (711) of the downward tab (710) of the second coupling profile (702) of an adjacent panel (700).Furthermore, in Figures 7a-7c there is represented the cooperation between the first or second additional locking element (706, 709) and the third additional locking element (713) to create a vertical locking effect in the coupled condition of two panels (700), defines a tangent TI (716) enclosing an angle A1 (717) with a plane (718) defined by the panel (700), which angle A1 (717) is smaller than an angle A2 (719) enclosed by said plane (718) defined by the panel (700) and a tangent T2 (720) defined by a joint action between an inclined portion of a near side (722) of the upward locking element (721) facing the third cavity (723) and an inclined portion of a near side (724) of the downward tongue (710) facing the second downward flank (725) respectively a portion inclined from a near side (726) of the side tab (708) facing the first downward flank (727). In the embodiments of the coupling profiles (701, 702, 703) shown in Figures 7a-7c, the first coupling profile (701) and the third coupling profile (703) respectively the second coupling (702) and the third coupling profile (703) are configured such that in the coupled condition a plurality of distant contact zones (728) are present, wherein between each pair of adjacent contact zones (728) there is a space (729). Specifically, Figures 7a and 7b show that the first downward flank (727) of the first coupling profile (701) and a distal side (730) of the upward locking element (721) and the lower flange (704) 5 of the third coupling profile (703), which face the first downward flank (727), are placed at a distance from each other.Additionally, the upper side (731) of the upward locking element (721) of the third coupling profile (703) is positioned at a distance from the upper side (733) of the first downward recess (732) of the first coupling profile (701). In Figure 7c it can be seen that the second downward flank (725) of the second coupling profile 10 (702) and a distal side (730) of the upward locking element (721) and the lower flange (704) of the third coupling profile (703), which face the second downward flank (725), are placed at a distance from each other. Furthermore, the upper side (731) of the upward locking element (721) of the third coupling profile (703) is placed at a distance from the upper side (734) of the second downward recess (712) of the second coupling profile (702).

Claims

1. A decorative panel, in particular a floor panel, ceiling panel, or wall panel, comprising: a core provided with an upper and a lower side, a decorative upper structure fixed to said upper side of the core, a first panel edge comprising a first coupling profile, and a second panel edge comprising a second coupling profile designed to interlock with said first coupling profile of an adjacent panel, both horizontally and vertically, wherein said core comprises: or at least one composite layer comprising: • at least one magnesium cement, • cellulose-based particles dispersed in said magnesium cement; and • at least one reinforcing layer embedded in said composite layer, wherein the magnesium cement comprises 5Mg(OH)2*MgSO4*3H2O (phase 513) and / or 3Mg(OH)2'MgSO4'8H2O (phase 318).

2. Panel according to claim 1, wherein the magnesia cement is based on magnesium oxide and / or magnesium hydroxide.

3. Panel according to one of the preceding claims, wherein the magnesia cement as such is free of magnesium oxide.

4. Panel according to one of the preceding claims, wherein the magnesia cement as such comprises magnesium hydroxide.

5. Panel according to one of the preceding claims, wherein the magnesia cement comprises water, in particular hydrated water.

6. Panel according to any of the preceding claims, wherein the magnesia cement comprises magnesium chloride.

7. Panel according to one of the preceding claims, wherein the magnesia cement comprises magnesium oxychloride.

8. Panel according to one of the preceding claims, wherein the magnesia cement comprises 5Mg(OH)2-MgCh· 8H2O.

9. Panel according to one of the preceding claims, wherein the magnesia cement comprises Mg2(OH) ClCOs'SEbO.

10. Panel according to one of the preceding claims, wherein the magnesia cement comprises magnesite, in particular hydromagnesite (Mgs(CO3)4(OH)2-4H2O).

11. Panel according to one of the preceding claims, wherein the magnesia cement is based on monoammonium dihydrogen phosphate (NH4H2PO4).

12. Panel according to one of the preceding claims, wherein the magnesia cement comprises struvite (NELMgPC^óEEO) and / or dittmarite (NELMgPCU^HiO).

13. Panel according to one of the preceding claims, wherein the magnesium cement comprises MgHPO4 14. Panel according to one of the preceding claims, wherein the magnesia cement is based on monopotassium phosphate (KH2PO4).

15. Panel according to one of the preceding claims, wherein the magnesia cement comprises magnesium potassium phosphate hexahydrate (MgKPO4*6H2O).

16. Panel according to any one of the preceding claims, wherein the magnesium cement comprises at least one borate.

17. Panel according to one of the preceding claims, wherein the magnesia cement is based on magnesium sulfate, in particular epsomite mineral sulfate heptahydrate (MgSO4-7H2O).

18. Panel according to one of the preceding claims, wherein the magnesia cement comprises at least 10% of 5Mg(OH)2*MgSO4*3H2O (phase 513).

19. Panel according to one of the preceding claims, wherein the magnesia cement comprises 5Mg(OH)2«MgSO4«5H2O (phase 515) and / or Mg(OH)2«MgSO4«7H2O (phase 517).

20. Panel according to any one of the preceding claims, wherein the composite layer comprises and / or is at least partially formed by the use of citric acid, in particular up to 0.5% by weight of citric acid.

21. Panel according to one of the preceding claims, wherein the composite layer comprises sodium silicate.

22. Panel according to one of the preceding claims, wherein the composite layer comprises sodium bicarbonate.

23. Panel according to one of the preceding claims, wherein the composite layer comprises dolomite.

24. Panel according to one of the preceding claims, wherein the composite layer comprises phosphoric acid (H3PO4) and / or at least one phosphate, in particular H2PO4.” 25. Panel according to one of the preceding claims, wherein the composite layer comprises at least one mineralized material selected from the group consisting of: sodium hydroxide (NaOH), calcium chloride (CaCl2), aluminum sulfate (Al2(SO4)3) and calcium hydroxide Ca(OH)2.

26. Panel according to one of the preceding claims, wherein the cellulose-based particles comprise lignocellulose.

27. Panel according to one of the preceding claims, wherein the cellulose-based particles comprise wood.

28. Panel according to one of the preceding claims, wherein at least a portion of the cellulose-based particles are formed from fibers.

29. Panel according to one of the preceding claims, wherein the cellulose-based particles comprise hemp fibers.

30. Panel according to one of the preceding claims, wherein at least a portion of the cellulose-based particles are formed from powder.

31. Panel according to one of the preceding claims, wherein at least a portion of the cellulose-based particles is formed from wood chips.

32. Panel according to one of the preceding claims, wherein at least a portion of the cellulose-based particles is formed from wool, in particular wood wool.

33. Panel according to one of the preceding claims, wherein at least a portion of the cellulose-based particles is formed from wood chips.

34. Panel according to any of the preceding claims, wherein the core comprises dispersed particles made of a material other than cellulose.

35. Panel according to any one of the preceding claims, wherein the composite layer comprises at least one additional filler selected from the group consisting of: steel, glass, polypropylene, wood, acrylic, alumina, curaua, carbon, cellulose, coconut, KVLAR, nylon, perlon, polyethylene, PVA, rock wool, sisal, and fique.

36. Panel according to one of the preceding claims, wherein the composite layer comprises sodium carboxymethylcellulose.

37. Panel according to one of the preceding claims, wherein the composite layer comprises fly ash.

38. Panel according to one of the preceding claims, wherein the composite layer comprises silica fume.

39. Panel according to one of the preceding claims, wherein the composite layer comprises iron oxide.

40. Panel according to any of the preceding claims, wherein the composite layer comprises fatty acids. 15 41. Panel according to one of the preceding claims, wherein the composite layer comprises alkali metal sulfates.

42. Panel according to one of the preceding claims, wherein at least one composite layer comprises at least one polymer, such as PVC or PUR.

43. Panel according to one of the preceding claims, wherein at least one composite layer is free of polymers.

44. Panel according to one of the preceding claims, wherein the composite layer comprises perlite, preferably expanded perlite.

45. Panel according to any one of the preceding claims, wherein the composite layer comprises at least one fire-retardant additive. 30 46. ​​Panel according to any of the preceding claims, wherein the composite layer is at least partially alveolated.

47. Panel according to one of the preceding claims, wherein the composite layer is free of plasticizer.

48. Panel according to one of the preceding claims, wherein the reinforcement layer is a non-woven layer or a woven layer, in particular a fabric.

49. Panel according to one of the preceding claims, wherein the reinforcing layer comprises glass fiber.

50. Panel according to one of the preceding claims, wherein the reinforcing layer comprises natural fibers, such as jute.

51. Panel according to one of the preceding claims, wherein the reinforcing layer comprises synthetic fibers, in particular polymeric fibers.

52. Panel according to one of the preceding claims, wherein the composite layer comprises at least 50% by weight, preferably between 50 and 90% by weight, of magnesia cement.

53. Panel according to one of the preceding claims, wherein the composite layer comprises between 1 and 15% by weight of cellulose-based fibers.

54. Panel according to one of the preceding claims, wherein the composite layer comprises between 0 and 3% by weight of perlite.

55. Panel according to one of the preceding claims, wherein the composite layer comprises between 1 and 8% by weight of reinforcing layer.

56. Panel according to any of the preceding claims, wherein at least one composite layer has a density greater than 1 kg / m3. bi cban / i ζηζ / α / γίΛΐ 57. Panel according to one of the preceding claims, wherein at least one composite layer has a density of less than 1 kg / m3.

58. Panel according to one of the preceding claims, wherein the core is provided with a waterproof coating that substantially covers at least one composite layer.

59. Panel according to one of the preceding claims, wherein a waterproof layer is located between the core and the upper structure.

60. Panel according to any of the preceding claims, wherein the composite layer comprises a plurality of reinforcing layers, wherein, preferably, at least a first reinforcing layer is located in an upper portion of the composite layer, and wherein at least a second reinforcing layer is located in a lower portion of the composite layer.

61. Panel according to one of the preceding claims, wherein the core comprises a laminate of composite layers, which are stacked directly and / or indirectly against each other.

62. Panel according to one of the preceding claims, wherein the core comprises a laminate of composite layers, wherein the composition of at least two composite layers is mutually different.

63. Panel according to one of the preceding claims, wherein the upper structure is adhered to the core by means of a waterproof adhesive.

64. Panel according to one of the preceding claims, wherein the upper structure comprises at least one decorative layer and at least one transparent wear layer covering said decorative layer.

65. Panel according to claim 64, wherein the wear layer has a melting temperature above 100 degrees Celsius, and wherein the wear layer is preferably made of polyurethane.

66. Panel according to one of the preceding claims, wherein the panel comprises a backing layer attached to a rear side of the core.

67. Panel according to one of the preceding claims, wherein at least one reinforcing layer extends over a single coupling profile of the first and second coupling profiles.

68. Panel according to one of the preceding claims, wherein the panel, preferably the core, comprises recycled material.

69. Panel according to one of the preceding claims, wherein the thickness of the panel is between 3 and 10 mm.

70. A panel according to any one of the preceding claims, wherein the first coupling profile comprises: • an upward-facing tongue, • at least one upward-facing flank located at a distance from the upward-facing tongue, • an upward-facing groove formed between the upward-facing tongue and the upward-facing flank, wherein the upward-facing groove is adapted to receive at least a portion of a downward-facing tongue of a second coupling profile of an adjacent panel, and • at least one first locking element, preferably provided on a side distant from the upward-facing tongue and facing in the opposite direction from the upward-facing flank, and wherein the second coupling profile comprises: • a first downward-facing tongue, • at least one first downward-facing flank located at a distance from the downward-facing tongue, • a first downward-facing groove formed between the downward-facing tongue and the downward-facing flank,wherein the downward-facing groove is adapted to receive at least a portion of an upward-facing tab of a first mating profile of an adjacent panel, and bl CbQn / l 7P7 / 3 / YILI • at least a second locking element adapted to cooperate with a first locking element of an adjacent panel, said second locking element being provided preferably on the downward flank.

71. A panel according to any of the preceding claims, wherein the panel comprises at least a third coupling profile and at least a fourth coupling profile located respectively on a third panel edge and a fourth panel edge, wherein the third coupling profile comprises: • a side tab extending in a direction substantially parallel to the upper side of the core, • at least a second downward flank located a distance from the side tab, and • a second downward groove formed between the side tab and the second downward flank, wherein the fourth coupling profile comprises: • a third groove configured to accommodate at least a portion of the side tab of the third coupling profile of an adjacent panel, wherein said third groove is defined by an upper flange and a lower flange, wherein said lower flange is provided with an upward locking element,wherein the third coupling profile and the fourth coupling profile are configured so that two of said panels can be coupled together by means of a rotational movement, wherein, in the coupled state: at least a portion of the side tab of a first panel is inserted into the third groove of an adjacent second panel, and wherein at least a portion of the upward locking element of said second panel is inserted into the downward second groove of said first panel.

72. Decorative cladding, in particular a decorative floor covering, decorative ceiling covering or decorative wall covering, comprising a plurality of decorative panels coupled together according to claims 1-71.