DECORATIVE PANEL AND COVER FOR SUCH DECORATIVE PANELS

Abstract

The invention relates to an interconnected decorative panel, in particular a floor panel, wall panel, or ceiling panel, provided with a tongue and groove. The invention also relates to a covering, in particular a floor covering, wall covering, or ceiling covering, composed of a plurality of interconnected decorative panels according to the invention.

Description

DECORATIVE PANEL AND COVER FOR SUCH DECORATIVE PANELS The invention relates to a decorative panel, in particular a floor panel, wall panel, or ceiling panel. The invention also relates to a covering, in particular a floor covering, wall covering, or ceiling covering, composed of multiple interconnected decorative panels according to the invention. The last few decades have seen enormous advancements in the flooring and flooring market. There are several known methods for installing flooring panels over an existing floor. For example, flooring panels can be attached to the subfloor either by gluing or nailing. This technique has the disadvantage of being somewhat complicated, and subsequent changes can only be made by removing the flooring panels. An alternative installation method involves laying the flooring panels loosely over the subfloor, where they interlock using a tongue-and-groove system. The resulting floor, also known as a floating floor, has the advantage of being easy to install and allowing the entire floor surface to move, which is often beneficial for accommodating expansion and contraction.Flooring options and requirements have also evolved. While flooring was generally made of wood and wood-based products such as MDF or HDF, traditionally known as laminate, the market has recently shifted towards plastic-based panels, such as PVC panels, and even mineral-based panels, such as magnesium oxide panels. Each of these alternatives has its advantages and disadvantages. One of the disadvantages of traditional panels, beyond the material itself, is that they are often difficult to assemble and ensure a tight seal, preventing water from seeping between them.If water seeps into the seams between panels, this can not only affect the panels if they are at least partially made of moisture-sensitive materials such as MDF and HDF, but it can also promote the growth of microbes between the panels, which is undesirable from a hygienic and sanitary point of view. A first purpose of the present invention is to provide improved contact between panels, in particular a waterproof contact between panels. A second purpose of the present invention is to provide a panel with an improved downward-angled assembly mechanism, in particular to achieve an essentially watertight contact between panels. QRzcnn / eznz / e / Y To that effect, the invention provides a decorative panel according to the preamble, comprising at least a first pair of opposing edges, a first interlocking piece, and a second interlocking piece that allows several of said panels to be coupled together, whereby these interlocking pieces, in the coupled state of two such panels, provide a fit in a first direction (R1) perpendicular to the plane of the panels, as well as in a second direction (R2) perpendicular to the relative edges and parallel to the plane of the panels, wherein said first interlocking piece comprises a side tab, wherein said side tab comprises a front region and a rear region, wherein an upper surface of the front region is preferably at least partially inclined downwards in a direction away from the front region,and where a lower and / or side surface of the rear region of said side tab defines a first contact portion, and where the side tab comprises a passive lower surface located adjacent to the first contact portion, wherein said second interlocking piece comprises a recess (or groove) to accommodate at least a portion of the side tab of another panel, and such recess is defined by an upper lip and a lower lip, where the lower lip extends beyond the upper lip, and where the lower lip is provided with an upwardly projecting shoulder defining a second contact portion configured to act in conjunction, in particular to act actively in conjunction with said first contact portion of another panel, in the coupled state of said panels, such that the panels are subjected to a force, in particular a tensile force (TI),at least laterally towards each other, where an upper surface of said lower lip is curved, in particular slightly curved, at least partially, and where said at least partially curved upper surface of the lower lip and said passive lower surface of the side tab are positioned reciprocally such that in the coupled state of two panels there is an adjacent intermediate space for the first and second contact portions to actively act together, and where a lower surface of the upper lip is preferably at least partially inclined and configured to splice at least a portion of the upper surface of the front region of the side tab of another panel. During installation, the panel to be installed is generally held at an angle against an already installed panel, with the side tab of the panel to be installed partially inserted into the groove of the already installed panel. The panel to be installed is then angled downwards, causing the side tab to fit snugly into the groove. This fitting effect creates a tight seal between the panels, preventing the 2 QRzcnn / eznz / e / YiAi water penetrates the seam. This method of assembly, where a panel is placed at a downward angle to be installed, is also called a downward-angled interlock. Depending on the shoulder height, the parts to be joined can also be configured to slide—essentially within a plane of the panel—and fit an interlocking piece of the first panel into the interlocking piece of the second panel. This method of assembly is also called a side-locking movement. Preferably, at least a portion of the upper surface of the shoulder, and more preferably essentially the entire upper surface of the shoulder, is oriented horizontally. Preferably, a lower surface of the first interlocking piece, generally located adjacent to the side tongue, which faces the shoulder in the joined state of the adjacent panels, is at least partially, and preferably entirely, oriented horizontally.Preferably, the shoulder and said opposite facing lower surface reciprocally contain a gap in the coupled state of adjacent panels, which will generally facilitate assembly. The panel according to the invention exerts a force (tension) between panels in a relatively effective manner through the combination of contact portions that act together and an adjacent intermediate space. This allows the contact portions to push the panels toward each other and close the seam between panels as firmly and watertightly as possible. Without this intermediate space adjacent to the contact portions, in the assembled state of the panels, it will be practically impossible to adjust the interlocking piece and / or less tension force will be exerted, leading to a less watertight seam between the upper surfaces of the panels. Preferably, a lower surface and / or a side surface of the front region are rounded and / or convex, at least partially. This generally facilitates the insertion of the side tongue into the mortise, as the outer end of the side tongue, also known as the nose, acts as a sliding surface during fitting. The lower surface and / or the side surface of the front region of the side tongue may be formed from the same surface, at least partially. Preferably, the rounded shape of the nose of the side tongue is a slightly rounded shape, meaning without sharp edges or other discontinuity. As mentioned above, in the coupled state of two panels, the passive lower surface faces, at a distance, the upper surface of the lower lip, allowing the contact portions to exert the desired prestress between the panels. It is generally preferred that this passive lower surface be defined by a portion cut out on one side. QAzcnn / eznz / e / YiAi lower part of the side tongue, most preferably resulting in an essentially flattened passive lower surface. Preferably, the at least partially rounded (section of the) upper surface of the lower lip is configured as a sliding surface for joint sliding action with the -preferably rounded- lower and / or side surface of the front region of the side tongue, during the interlocking of two panels. Preferably, at least a portion of the upper surface of the lower lip is slightly curved, meaning without sharp edges or other discontinuity. This will facilitate the interlocking process. Preferably, at least a portion of the upper surface of the lower lip is slightly curved according to an essentially constant radius.An additional advantage of this embodiment is that the interlocking pieces are relatively easy and practical to produce compared to more complicated interlocking pieces. Preferably, the upper surface of the essentially entire lower lip is slightly curved according to an essentially constant radius. This will generally facilitate the sliding of the side tongue into the recess during the interlocking of adjacent panels. Furthermore, such a constant radius can be achieved using a single milling tool, which is advantageous from an economic and efficiency standpoint. Preferably, the lateral surface of the front region of the side tab and an opposing portion of the upper surface of the lower lip are formed in an essentially complementary manner, and preferably in a slightly curved, essentially complementary manner. This allows the side tab to be designed as robustly as possible, while minimizing the amount of material removed to create the recess, thus avoiding unnecessary weakening of the second interlocking piece. Preferably, the lateral surface of the front region of the side tab and an opposing portion of the upper surface of the lower lip are at least partially spaced and separated, and reciprocally contain a (front) gap. Preferably, the front gap is smaller than a lower gap defined by the passive lower surface of the side tab and an opposing portion of the upper surface of the lower lip.Preferably, the maximum distance a between the lateral surface of the anterior region of the lateral tongue and an opposing part of the upper surface of the lower lip is smaller than the maximum distance b between the passive lower surface of the lateral tongue and an opposing part of the upper surface of the lower lip. QRzcnn / eznz / e / YiAi Preferably, as mentioned above, a lower surface of the upper lip is inclined downwards towards a core of the panel, and an upper surface of the front region of the side tongue is also inclined downwards in a direction away from said core of the panel. Here, the angles of inclination can be the same. Each angle of inclination is preferably between (and inclusive of) 20 and 30 degrees with respect to the plane defined by the panel. This inclination can considerably facilitate the interlocking process and ensure that the panels are fully flush-fitted.Furthermore, this inclined orientation can contribute to increasing the tensile force between the panel, since, in the interlocking position, pre-tension between the lower surface of the upper lip and the upper surface of the front region of the side tongue may be present, and this pre-tension can be transferred to the contact portions and / or the essentially vertical contact surfaces that define the seam between two panels. The decorative panel according to the invention is primarily intended for interior use, but can also be used outdoors. The decorative panels according to the invention are generally of limited thickness (20 millimeters or less) and are designed to be installed as a floating floor covering, preferably without the use of rubber underlayment. Their use is specifically intended for residential, office, commercial, and similar applications. In particular, the applications described herein in laminate flooring are understood to be those where a decorative top layer—generally waterproof—is applied over a core layer of the panel. This core layer is often made of wood, wood-based material, particleboard, and / or fiberboard, such as medium-density fiberboard (MDF) or high-density fiberboard (HDF).However, alternative materials such as thermoplastics, particularly polyvinyl chloride (PVC) and / or polyurethane (PU), and / or minerals, such as calcium carbonate and / or magnesium (hydro)oxide and / or calcium (hydro)oxide, can also be used to make up at least part of the core layer(s). A slip agent, such as paraffin, oil, wax, or similar substances, can be applied to the contact areas of the decorative floor panels to facilitate interlocking and possibly also make the interlocking parts more water-repellent, which can promote a watertight seal between the assembled parts. Further on, other preferred embodiments of the panel according to the invention are presented. As mentioned, preferably, the passive bottom surface is at least partially flat or flattened, which is easy to achieve during production and ensures the presence of the 5 QRzcnn / eznz / e / YiAi intermediate space. It is imagined that, preferably flattened, the passive lower surface is at least partially inclined in a direction towards the front region, with respect to the panel plane. Here, the inclined upper surface of the side tongue and the inclined passive lower surface preferably converge in a direction away from the rear region of the side tongue. The angle of inclination between the inclined upper surface of the side tongue and the inclined passive lower surface is preferably less than 15 degrees, more preferably less than 10 degrees, and may be, for example, 5 degrees. This will result in a relatively thin nose of the side tongue while allowing the rear region of the side tongue to remain relatively robust, which in turn will make possible a firm tongue that can be inserted relatively easily into the recess.For the purposes of integrity, it should be noted that the passive lower surface need not necessarily be a flat surface, and may, for example, also be a concave surface and / or a convex surface and / or a profiled surface, provided that the intermediate space is formed in the coupled state of two embedded panels. Preferably, the upper surface of the lower lip defines a deeper point of the recess, and in the case of two interlocking panels, this deeper point is located at a distance from—and opposite—the passive lower surface. This means that if the nose of the side tab slides over the upper surface of the lower lip during interlocking into the final fixing position, the nose initially moves (slides) downward and then upward, facilitating the correct placement of the nose in the side tab position and allowing the lower surface of the upper lip and the upper surface of the anterior region of the side tab to align with each other. Preferably, the upper surface of the lower lip defines a deeper point of the rebate, where the shoulder of the lower lip defines a higher point of the lower lip, where such a deeper point and such a higher point define a lower lip depth (LLD), and where the first and second contact portions are located entirely above the midpoint (i.e., 50%) of the lower lip depth. It is generally preferred to position the contact portions as high as possible to allow them to efficiently transfer a clamping force between the contact portions to the essentially vertical contact surfaces of two panels that define the seam formed between the panels. In a preferred embodiment, the upper surface of the lower lip has a deeper point of indentation, where the shoulder of the lower lip defines a higher point of the lower lip, where such a deeper point and such a higher point define a depth of the lower lip 6 QRzcnn / eznz / e / YiAi (LLD), and wherein the minimum thickness (STD) of the side tab, measured between the at least partially inclined upper surface and the passive lower surface of the side tab, exceeds the depth of the lower lip. This means that the thickness of the side tab is relatively thick compared to the depth of the lower lip, which also means that a portion of the side tab is positioned above the shoulder (level) of the lower lip. This typically results in panel interlocking pieces according to the invention that are more robust and therefore less vulnerable. Preferably, the first contact portion is inclined upwards in a direction away from the front region of the side lip, where the first inclined contact portion and the panel plane preferably form an angle of at least 45 degrees, and where the second contact portion is inclined upwards in a direction away from the top lip, where the second inclined contact portion and the panel plane preferably form an angle of at least 45 degrees. These angles of inclination generally have a sufficiently large horizontal component (parallel to the panel plane) to exert sufficient tensile force to create a watertight (waterproof) contact between the panels.Although the first and second contact portions can extend in slightly different directions, it is generally preferred that they extend in essentially parallel directions. This parallel alignment will usually facilitate the sliding of the second contact portion over the first during panel installation. Preferably, the lower and / or lateral surface of the anterior region of the side tab are configured to work in conjunction with the lower lip in the coupled state of the two panels, and together they define a lower anterior contact surface. This lower anterior contact surface generally provides (additional) stability and (furthermore) locks the interlocking pieces in the coupled state. Preferably, the entire lower anterior contact surface is located below the level of the first and second contact portions. This results in a situation where the side tab has an inclined orientation (inclined heart line) in both the coupled and uncoupled states, which is efficient in securing the side tab between the lower and upper lips.Furthermore, this position of the lower anterior contact surface can increase the bonding force between the contact portion and, consequently, the bonding forces between the essentially vertical contact surfaces on the upper surface of adjacent or nearby panels. Preferably, the surface of 7. The lower anterior contact of one side and the contact surface defined by the first and second contact portions of the other side contain reciprocal angles of between 70 and 110 degrees, preferably between 80 and 100 degrees, more preferably essentially 90 degrees (± 23 degrees). Generally, a larger angle affects the locking effect of the side tab, while a smaller angle will generally prevent the interlocking of the interlocking pieces. Typically, the (upper) seam formed by (or between) two panels in the mated state defines a vertical plane (VP). This vertical plane is perpendicular to the panel plane. Preferably, this vertical plane subdivides the lower lip into an inner lower lip portion and a lower lower lip portion. Preferably, at least a portion, and more preferably the entire lower contact surface (already mentioned), as well as the first and second contact portions, are located on the same side of the vertical plane. This results in a relatively large distance and / or an inclined orientation between, on the one hand, the second contact portions, defined by the lower surface of the upper lip and the splice portion of the upper surface of the front region of the side tongue of another panel, and on the other hand, the lower contact surface, which facilitates the interlocking and securing of adjacent panels.The upper lip is generally located entirely on the same side of the vertical plane. The upper surface of the anterior region of the lateral tab preferably intersects the vertical plane (VP). Here, the larger portion of this upper surface is located below (and more preferably in contact with) the lower surface of the upper lip. The entire upper surface (portion) of the lower lip that extends between the vertical plane (VP) and the second contact portion is preferably formed by a slightly curved surface, which is more preferably configured to act as a sliding surface to facilitate assembly. Preferably, the seam formed by two panels in the joined state defines a vertical plane (VP), where said vertical plane subdivides the lower lip into an inner lower portion and a lower lower portion, and where, in the joined state, the entire lower surface and the entire side surface (if these surfaces are distinct) of the inner lower lip portion are positioned at a distance from the second interlocking piece, in particular the side tab. The upper surface of the lower lip is (more preferably) provided with a stepped and / or cut-out portion (and / or stepped portion), which is located at least partially below the upper lip, and which is configured to accommodate a terminal portion of the side tab of another panel.This stepped and / or trimmed portion can create a desired space between the middle of the side tongue nose and an upper surface of the lower lip, which can 8. QRzcnn / eznz / e / YiAi not only facilitates the fit but also allows the side tab to expand to some extent during normal use, due to, for example, moisture absorption and / or heating. Preferably, the upper lip and the stepped or cut portion of the lower lip are configured to secure the terminal portion (i.e., the nose) of the side tab. This can further enhance the fit between the interlocking pieces. Preferably, the stepped and / or cut portion and / or the stepped portion is located entirely beneath the upper lip, as this is normally where the nose of the side tab will be positioned in the attached state. Preferably, the upper surface of the lower lip comprises a posteriorly curved upper surface and an anteriorly curved upper surface, wherein the posterior and anterior upper surfaces are staggered relative to each other, and wherein the anterior upper surface is preferably deeper than the posterior upper surface. The curvatures of the posterior and anterior upper surfaces may vary from each other, but are preferably essentially identical. Due to the staggered orientation, the hypothetical centers of the curvatures of the anterior and posterior upper surfaces do not coincide and are spaced apart from each other.Therefore, the rear upper surface and the front upper surface are preferably deeper than the rear upper surface, which is generally achieved by removing additional material (machining) during production. This creates slightly more space to accommodate the outer end (the tip) of the side tab. As mentioned, the transition between the front upper surface and the rear upper surface is preferably made by means of a stepped section. Preferably, the panel defines a top surface and a bottom surface, and together these define the panel thickness (PT). The shoulder thickness (or height) (ST), measured from the bottom surface of the panel to the highest point of the shoulder, exceeds 30%, preferably 50%, of the panel thickness (PT). As explained, by applying a relatively thick (or high) shoulder, the contact portions can be positioned at a higher level, which helps to efficiently transfer the clamping force from the contact portions of the top seam formed between the panels, and thus produces a relatively close contact between the panels at that top seam. In the assembled state of the panels, an upper shoulder surface is preferably positioned at a distance from a facing lower surface of the first interlocking piece. This prevents 9 QRzcnn / eznz / e / YiAi The upper surface of the shoulder and the opposite lower surface of the first interlocking piece act together, which could affect the desired tensile strength between the panels. Therefore, this means that the contact portions are contained by two gaps: the aforementioned intermediate gap and the gap above the shoulder. Preferably, the upper surface of the shoulder is essentially parallel to the panel plane. Preferably, the opposite lower surface of the second interlocking piece is also essentially parallel to the panel plane. In this way, both components can be made relatively robust without creating a weak area in the shoulder and / or the opposite lower surface of the second interlocking piece. The lower lip is preferably positioned entirely below (i.e., at a lower level in comparison) the upper lip. This facilitates the insertion of the lateral tongue into the indentation. Preferably, the upper surface of the anterior region of the side tab and a lateral surface of the anterior region of the side tab are connected by a convex transition surface, and / or the lower surface of the upper lip and a lateral surface of the upper lip are connected by a convex transition surface. These one or more convex surfaces can act as sliding surfaces during the interlocking of the interlocking parts, particularly during lateral movement for engagement. In the decorative panel according to the invention, the first and second interlocking pieces are also provided with at least a second pair of opposing edges. This means that all the edges of the panel are configured to interlock with a downward angle. This design of different first interlocking pieces on different panel edges can be identical, but it can also be different; the same applies to the different second interlocking pieces. For example, in the case of oblong (rectangular) panels, it is reasonable to imagine that on the short edges the shoulder thickness is either lower or higher than the shoulder thickness on the long edges, and the same can be said for other components of the interlocking pieces. Such a panel is also called an angle-to-angle panel, which is functional but may not be easy to install.Therefore, it is commonly preferred that the panel comprise at least a following, in particular a second, pair of opposing edges, a third interlocking piece and a fourth interlocking piece that allows several such panels to be coupled together by a downward or vertical movement, where these interlocking pieces, in the coupled state of two such panels, produce a lock in a first direction (R1) perpendicular to the plane of the panels, as well as in a second direction (R2) perpendicular to the respective edges and parallel to the plane of the 10. QRzcnn / eznz / e / YiAi panels, wherein the third interlocking piece comprises a rising tongue, at least one rising flank located at a distance from the rising tongue, and a rising groove formed between the rising tongue and the rising flank, wherein the rising groove is adapted to receive at least a portion of a falling tongue of the fourth interlocking piece of another panel, wherein the side of the rising tongue facing the rising flank is the inside of the rising tongue and the side of the rising tongue facing away from the rising flank is the outside of the rising tongue, wherein the fourth interlocking piece comprises a falling tongue, at least one falling flank located at a distance from the falling tongue, and a falling groove formed between the falling tongue and the falling flank,where the descending groove is adapted to receive at least a portion of the ascending tongue of the third interlocking piece of another panel, where the side of a descending tongue facing the descending flank is the interior of the descending tongue and the side of the facing descending tongue moving away from the descending flank is the exterior of the descending tongue. Preferably, the interior of the ascending tongue and the interior of the descending tongue of another panel are configured to act in conjunction with the interior of the descending tongue of another panel, in the coupled state of said panels, such that the panels are subjected to a tensile force (T2) at least laterally to each other. The tensile force (T2) contributes to achieving a firm and preferably watertight interlock between the third and fourth interlocking pieces. Preferably, at least a portion of the interior of the rising tongue is inclined towards the rising flank, and at least a portion of the interior of the falling tongue is inclined towards the falling flank. This "closed groove" interlocking mechanism could allow two panels to be locked in the first direction (R1). In an alternative embodiment, at least a portion of the interior of the rising tongue is inclined away from the rising flank, and at least a portion of the interior of the falling tongue is inclined away from the falling flank. This "open groove" interlocking mechanism generally allows the third and fourth interlocking pieces to be connected more easily. Preferably, the exterior of the rising tab is provided with a first locking element, and the descending flank is provided with a second locking element configured to act in conjunction with the first locking element of another panel. This would allow two panels to be locked in the first direction (R1). The first locking element preferably comprises a protrusion, and the second locking element preferably comprises a recess, where the exterior of the protrusion comprises an upper portion and a portion 11 QRzcnn / eznz / e / YiAi adjacent lower portion, where the lower portion comprises an inclined locking surface and the upper portion comprises a preferably curved guide surface, where said recess comprises an upper portion and an adjacent lower portion, where the lower portion comprises an inclined locking surface, where in the coupled state of adjacent panels, the inclined locking surface of the lower portion of the protrusion and the inclined locking surface of the lower portion of the recess are in contact to produce such a locking effect between the panels and / or where, in the coupled state of adjacent panels, the upper portions of the first locking element and the second locking element are preferably spaced, at least partially.Preferably, the length of the inclined blocking surface of the lower portion of the protrusion is greater, preferably at least 1.5 times greater than the inclined blocking surface of the lower portion of the inlet. Preferably, the upper portion extends over a larger vertical section compared to the lower portion, where preferably the height of the upper portion is at least three times the height of the lower portion. The first locking element, located on the outside of the rising tongue, will encounter the descending flank of another panel during interlocking. This is because it is the projecting portion of the panel, and is usually the outermost portion on one side. The forces required to force one panel into the other must be overcome during interlocking. By providing a (curved) guide surface on the upper portion, the rear or other panel is directed downwards, allowing the interlocking to occur gradually and preventing large deformations and / or stress peaks in the material. The lower portion can then be inclined, forming the protrusion that curves back towards the rising tongue from the outermost part of the protrusion. This inclined surface also serves as a guide, directing the panels towards their final position.The inclination of the locking surface also allows a potential upward force or movement of the panels to result in a vertical and horizontal force component. The horizontal component can be used to hold the panels together, forcing them towards each other to improve contact and the waterproofing properties of the panel-to-panel interface. The second locking element can be a recess comprising an upper portion and an adjacent lower portion, where the lower portion comprises an inclined locking surface, for the purpose of acting in conjunction with the first locking element. Inclined surfaces also have the advantage, for example over rounded surfaces, of being relatively easy to manufacture or mill, and it is relatively easy to create a contact surface 12. QRzcnn / eznz / e / YiAi relatively large gap between the two to expand the locking forces on the interlocking panels. The upper portion can extend over a larger vertical section compared to the lower portion, to guide the panels gradually into place. The upper portion generally does not provide a vertical locking effect, so its horizontal portions are less relevant compared to the lower portion, which generally provides a vertical locking effect. The parts of the first and second locking elements that are in contact, in the coupled state of the panels, are generally formed by the inclined locking surfaces of the locking elements, as well as by the lower portions. In the coupled state of the panels, the upper portions of the first and second locking elements may be spaced apart, at least partially.This space allows the ascending tongue to move upwards without being obstructed by the descending flank, whose upward movement can in turn be transferred and translated into a horizontal approach movement to improve contact or locking of the panels, forcing the panels to come together. The exterior of the rising tongue may comprise an upper outer portion and a lower outer portion, where the first locking element appears between the upper and lower outer portions, the lower outer portion being closer to the interior of the rising tongue compared to the upper outer portion. The upper outer portion may preferably be essentially vertical and defines an external vertical plane, where the first locking element projects at least partially from the external vertical plane, preferably by a maximum of 2 mm. For example, the upper outer portion above the first locking element defines one vertical plane and the lower outer portion below the first locking element defines another vertical plane, which are parallel but offset, with the vertical plane of the lower outer portion located closer to the rising flank.This difference creates a relatively long distance between the panels at the intersection between the inclined locking portion of the rising tongue and the outer lower portion, allowing for a greater upward angle or rotational movement of the rising tongue and thus a greater potential approach or tensile force exerted by the locking elements to improve the connection and waterproof properties of the panels. The lower outer portion can be essentially vertical, and the inclined locking surface, or the lower portion and the lower outer portion, contain an angle of between 100 and 175 degrees, particularly between 100 and 150 degrees, and more specifically between 110 and 135 degrees. Such an angle has proven to allow the best combination of locking and guiding properties. The contained angle 13 QRzcnn / eznz / e / YiAi by the upper contact surfaces and the inclined contact surfaces and the angle contained by the lower outer portion and the inclined outer surface or the lower portion may be within 20 degrees of difference and preferably is the same. This allows for relatively easy manufacturing where the same or a similar tool can be used to mill both elements of a panel. An outer portion of the first locking element can be positioned horizontally lower than the ascending groove. This ensures that, during the downward movement of the panels during assembly, the wider outer portion of the first locking element intersects relatively late, facilitating the coupling of two panels. Adjacent to, and generally directly adjacent to or directly below, the upper contact surfaces, there may be an inclined contact surface. The panels are in contact on these inclined surfaces, creating a seal between them. The inclination is preferably such that, when viewed from the downward tongue, the inclined surface extends outward, and when viewed from the upward flank, the inclined surface extends inward. The angle of inclination is formed so that the downward tongue has a protruding portion and the upward flank has a recessed portion, which, when mated together, are in contact and thus provide a vertical locking effect. The inclination also creates a slight labyrinth, which enhances the watertight properties of the connection. Adjacent to, and generally directly adjacent to or directly below, the inclined contact surface, the downstem may comprise an outer surface. This outer surface may, for example, be the outermost surface of the downstem or the outermost surface of the downstem furthest from the downstem. Equally adjacent to, and generally directly adjacent to or directly below, the inclined contact surface, the upstem comprises an inner surface. A gap exists between the inner and outer surfaces. This gap is designed so that any force exerted on or by the panels pushes the panels against each other at locations other than the upper contact surfaces and / or the inclined contact surfaces.If the inner and outer surfaces were to come into contact, they could prevent the contact surfaces from making contact, which would compromise the waterproof properties of the contact. Therefore, at the top, on the upper contact surfaces, and on the inclined contact surfaces, the purpose is to create a connection between the panels, while below these contact surfaces, the purpose is to prevent such a connection. The upper contact surfaces may be at least partially vertical and define a 14. QRzcnn / eznz / e / YiAi internal vertical plane, where the inclined contact surface of the descending tongue extends beyond the internal vertical plane, preferably by a maximum of 1 mm in the horizontal direction, and where the inclined contact surface of the rising flank is inwardly positioned relative to the internal vertical plane. This configuration is such that the descending tongue projects beyond the internal vertical plane, and the rising flank is locally inwardly recessed, where in the engaged state the inclined contact surfaces can grip each other from behind to create a vertical locking effect. A portion of the descending tongue can thus extend beyond the internal vertical plane, this portion being made longer with a larger vertical portion relative to the horizontal portion, where preferably the vertical portion is at least three times the horizontal portion.This allows for a relatively small horizontal portion so that the panels can still be connected with a vertical or downward movement. A portion of the descending tongue can then extend beyond the interior vertical plane, where it can be essentially trapezoidal or wedge-shaped. This shape allows the portion, when subjected to locking, interlocking, or other forces in the plane of the panels, to be wedged into the space provided on the rising flank, while providing a robust, force-bearing portion to create a tight contact between the panels. This, in turn, improves the watertight properties of the panel connection. The inclined contact surfaces can be located on the exterior and / or adjacent to the interior vertical plane, and are positioned either entirely outside the interior vertical plane or entirely on one side of it. This allows for a relatively simple construction that provides close contact between two panels. Preferably, the upper contact surfaces, which define the vertical plane, serve directly as a transition to the interior of the inclined contact surfaces. In such a configuration, the connection between the contact surfaces continues from the upper contact surfaces to the inclined contact surfaces, increasing the uninterrupted surface area and thereby improving the connection between the panels and the waterproofing properties of the joint.In the engaged state, a lower portion of the descending tongue can make contact with the upper side of the ascending groove on a groove contact surface, and where there is a gap between the first and second interlocking pieces, extending from the inclined contact surfaces to the groove contact surface. This gap can be used to collect, for example, dust or burrs from the panels, potentially produced during the interlocking of two panels. Furthermore, this gap points to 15. QRzcnn / eznz / e / YiAi to prevent any force exerted on or by the panels from pushing the panels against each other at any point other than the upper contact surfaces and / or the inclined contact surfaces. The contact surface of the groove is preferably primarily horizontal, and allows forces exerted on the panel, and in particular on the connection between two panels, generally in a downward direction when placed on the panel, to be transferred to the subsoil or the surface beneath the panels. A top surface of the rising tongue and a top surface of the falling groove may, in the mated state, be positioned at a distance from each other such that a gap exists between the two surfaces. This gap prevents a force exerted on or by the panels from pushing them together at any point other than the upper contact surfaces and / or inclined contact surfaces. An upward movement of the upper tongue may, for example, result in a horizontal force that closes or tightens the contact between two panels, particularly in so-called closed-groove locking contacts. To allow this movement, the gap between the rising tongue and the falling groove is present. The upper surface of the falling groove may, for example, be formed by the lower surface of a bridge connecting the falling tongue to the rest of the panel. The upper contact surface and the inclined contact surface of the rising flank may contain a first angle, and the upper contact surface and the inclined contact surface of the falling tongue may contain a second angle, where the first and second angles differ by less than 20 degrees. For example, the inclined contact surface of the rising flank may contain a first angle of 120 degrees, and the upper contact surface and the inclined contact surface of the falling tongue may contain a second angle of 125 degrees. The difference between the two angles is 5 degrees, which is within 20 degrees since it is less than 20 degrees. By creating a difference between the angles, a configuration can be achieved where a wedge action can be used to increase the locking forces and the waterproofing properties of the contact.Pushing or wedging the locking elements together can result in increased locking forces or contacts on the panels. Preferably, the rising flank and the outer edge of the falling tongue define vertical upper contact surfaces of the panel, and where the upper contact surfaces of both the falling tongue and the rising flank are adjacent, they comprise an inclined contact surface, where the inclined contact surface of the falling tongue of said 16 QAzcnn / eznz / e / YiAi panel is configured to engage the inclined contact surface of the rising flank of an adjacent panel, in the mated state of said panels, wherein each essentially vertical upper contact surface and each adjacent inclined surface reciprocally contain an angle (a) of between 100 and 175 degrees. Preferably, the outside of the descending tongue is provided with a third locking element, such as a protrusion or recess, and wherein the rising flank is provided with a fourth element, such as a recess or protrusion, configured to act in conjunction with the third locking element of another panel, thereby enabling two panels to be locked in the first direction (Rl).More preferably, the third locking element is at least partially defined by the upper contact surface of the descending tab, and where the fourth contact element is at least partially defined by the upper contact surface of the ascending flank. Preferably, at least a portion of each interlocking piece forms an integral part of a core layer of the panel. In other words, the side surface of the core may be shaped or profiled such that these profiled edges at least partially form the interlocking portions. Preferably, the panel comprises at least one core layer and at least one decorative top structure, directly or indirectly attached to said core layer, where the top structure or top section defines a top surface of the panel. Typically, this top structure (or top section) is waterproof and thus protects the core, which may or may not be composed of a moisture-sensitive material, from water (and other liquids). Preferably, the top section comprises a printed decorative layer and at least one wear layer covering said printed decorative layer.Due to the improved water resistance of the interlocking pieces, including the first interlocking piece and the second interlocking piece, this allows one or more core layers to be at least partially composed of a moisture-sensitive material such as wood, medium-density fiberboard (MDF), or high-density fiberboard (HDF). The panels may comprise a layered structure, comprising, for example, a central core (or core layer) and at least one decorative top section, where the top section defines a top surface of the panel. The top section preferably comprises at least one decorative layer affixed directly or indirectly to a top surface of the core layer. The decorative layer may be a printed layer, such as a printed PVC layer, a printed PU layer, or a printed paper layer, and / or may be covered by at least one protective (top) layer covering such decorative layer. The protective layer is also part of the top section. QRzcnn / eznz / e / YiAi decorative. The presence of a printed layer and / or a protective layer can prevent the tile from being damaged by scraping and / or due to factors such as UV / humidity and / or wear and tear. The printed layer may consist of a film onto which a decorative print is applied, where the film is fixed onto a substrate layer and / or an intermediate layer, such as a primer layer, situated between the substrate layer and the decorative layer. The printed layer may also consist of at least one ink layer applied directly onto a top surface of the core layer, or onto a primer layer applied to the substrate layer. The panel may comprise at least one wear layer fixed directly or indirectly to a top surface of the decorative layer. The wear layer is also part of the decorative top section.Each panel may comprise at least one layer of lacquer fixed directly or indirectly to an upper surface of the decorative layer, preferably to an upper surface of the wear layer. The underside (back side) of the core layer or layers can also constitute the underside (back side) of the panel itself. However, it is reasonable to assume, and may even be preferable, that the panel comprises a support layer directly or indirectly attached to this underside of the core. The support layer typically acts as a balancing layer to stabilize the shape, particularly the flattening of the panel. Furthermore, the support layer generally contributes to the panel's good wetting properties. Since the support layer is usually a closed layer, applying it to the underside of the core will cover the core grooves at least partially, and preferably completely. Here, the length of each core groove is preferably less than the length of the support layer.The backing layer may be provided with cut-out portions, where at least part of said cut-out portions overlaps with at least one groove of the core. The at least one backing layer is preferably made at least partially of a flexible material, preferably an elastomer. The thickness of the backing layer generally varies between about 0.1 and 2.5 mm. Non-limiting examples of materials from which the backing layer may be at least partially composed are polyethylene, cork, polyurethane, polyvinyl chloride, and ethylene vinyl acetate. Optionally, the backing layer comprises one or more additives, such as pore fillers (like chalk), dyes, resins, and / or one or more plasticizers. In one particular embodiment, the backing layer is made at least partially of a composite of ground (or deburred) cork particles bonded with resin. Other tree-based products, such as wood, may be used instead of cork.The thickness of a polyethylene support layer is usually 2mm or less, for example. The support layer can be 18. QRzcnn / eznz / e / YiAi can be solid or agglomerated. An agglomerated support layer can maximize the good humidification properties. A solid support layer can improve the desired balance effect and stability of the panel. In a preferred embodiment, at least one core layer comprises at least one main polymer and at least one plasticizing composition, preferably comprising polyvinyl butyral (PVB), most preferably at a content of 35-65% by weight. This plasticizing composition has the advantage over conventional plasticizers used in flooring panels of being relatively safe to use and less toxic. Thus, a plasticizing composition is proposed that is suitable for incorporation into the decorative panel, particularly in the core (and / or another layer) of the decorative panel. At the same time, the panel is inherently elastically deformable due to the inclusion of the plasticizing composition within the material layer.Furthermore, it has been found that in the claimed panel, the components included in the plasticizing composition do not tend to migrate through the main polymer matrix. This prevents detrimental leaching of the plasticizing components from the matrix when incorporating the plasticizing composition as claimed. Likewise, the plasticizing composition used in the panel according to the invention is a polymer-based plasticizing composition, preferably phthalate-free, and is therefore different from conventional plasticizers. Consequently, the polymer-based plasticizing composition used in the panel according to the invention can also be considered a flexibilizer composition, or simply a flexibilizer.The presence of this flexibilizing composition (or flexibilizer) imparts a desired flexibility (resilience) to the panel's material layer(s), and therefore to the panel itself, making it more difficult to break and thus less vulnerable. This also facilitates proper installation of the panel on, for example, a (slightly) uneven floor, and further improves the panel's acoustic properties (both sound transmission and sound reflection). Panels according to the invention can even be made flexible enough to be rolled up, which can facilitate their storage and / or transport before installation. It is therefore conceivable that the panel consists of a strip (or sheet) presented as a roll that is unrolled for installation. The length of this strip is generally between 1 and 30 meters.The panel can, for example, be elongated and have a width of between 10 and 100 cm, and a length of between 50 and 250 cm. The polymer blend compound used in at least one layer of the core material is primarily intended to be a completely non-plasticizer. QAzcnn / eznz / e / YiAi migrating plasticizer for flexible polymer-based panels and / or modifying the impact of other polymers where both elastic and acoustic properties (sound mitigation) are improved. If PVB is used as the sole plasticizing additive in, for example, a PVC-based core, there is generally poor compatibility between PVB and PVC, resulting in a limited plasticizing effect and brittleness of the mixture. Here, a less successful microstructure (with microvolumes of PVB in a PVC-based matrix) can also result in undesirable drawbacks such as lower tear resistance, risk of partial deterioration over time, and risk of uneven hardening fracture. According to the present invention, by including PVB in a non-migrating solid-state plasticizer, and by mixing PVB with one or more alloy copolymers, the aforementioned drawbacks of using PVB as a plasticizer, especially in PVC, are avoided.Furthermore, PVB can be maximized and the properties of the final polymer matrix optimized. Key improvements include enhanced elongation at break, changes in flexural modulus and tensile strength, improved robustness, and sustained surface tension. This opens up new possibilities for panel design, particularly because this type of polymer-based plasticizer composition is scalable, and the blend's microstructure is reproducible and homogeneous. The panels according to the invention may also be at least partially made of magnesium oxide. More particularly, the panel according to the invention may comprise: at least one core layer provided with a top and a bottom side, and a decorative top structure (or top section) fixed directly or indirectly onto such top side of the core layer, wherein at least one core layer comprises: at least one composite layer comprising: at least one composition with magnesium oxide (magnesia) and / or magnesium hydroxide, in particular a magnesia cement. Particles, in particular cellulose-based and / or silicone-based particles, may be dispersed in said magnesia cement. Optionally, one or more reinforcing layers, such as fiberglass layers, may be embedded in said composite layer.The core composition may also include magnesium chloride, resulting in a magnesium oxychloride (MOC) cement, or magnesium sulfate, resulting in a magnesium oxysulfate (MOS) cement. The application of a magnesium oxide and / or magnesium hydroxide-based composition, and in particular a magnesia cement, including MOS and MOC, has been found to significantly improve the non-flammability (incombustibility) of the decorative panel. Furthermore, the relatively fire-resistant panel also exhibits significantly improved dimensional stability when subjected to fluctuations.20 QRzcnn / eznz / e / YiAi of temperature during normal use. Magnesia-based cement is cement that is based on magnesia (magnesium oxide), where the cement is the product of a chemical reaction in which magnesium oxide has acted as one of the reactants. In magnesia cement, magnesia may still be present and / or have undergone a chemical reaction where another chemical bond is formed, as will be explained in more detail later. Additional advantages of magnesia cement, also compared to other types of cement, are presented below. A primary advantage is that magnesia cement can be manufactured efficiently and economically. Furthermore, magnesia cement has relatively high tensile and compressive strength.Another advantage of magnesium cement is its natural affinity for cellulose materials—generally inexpensive—such as wood fiber dust (sawdust) and / or wood chips. This not only improves the bonding of the magnesium cement but also saves weight and adds sound insulation (damping). Magnesium oxide, when combined with cellulose and optionally clay, creates breathable magnesium cement; this cement does not deteriorate (rot) because it effectively expels moisture. Furthermore, magnesium cement is a relatively good insulating material, both thermally and electrically, making the panel particularly suitable as flooring for radar stations and hospital operating rooms.An additional advantage of magnesia cement is its relatively low pH compared to other types of cement. This allows for greater durability of fiberglass, whether as particles dispersed within the cement matrix and / or (as fiberglass) as a reinforcing layer. It also allows for the durable use of other types of fibers. Furthermore, another advantage of the decorative panel is its suitability for both interior and exterior applications. As noted, magnesia cement is based on magnesium oxide and / or magnesium hydroxide. Magnesium cement itself may be free of magnesium oxide, depending on the other reactants used in its production. For example, it is reasonable to assume that magnesia, as a reactant, is converted to magnesium hydroxide during the manufacturing process. Therefore, magnesia cement may contain magnesium hydroxide.Magnesia cement typically comprises water, particularly hydrated water. Water is normally used as a binder to create a strong and cohesive cement matrix. Magnesia-based compositions, particularly magnesia cement, may include magnesium chloride (MgCl2). Typically, when magnesia (MgO) is mixed with magnesium chloride in an aqueous solution, a magnesia cement comprising magnesium oxychloride (MOC) will be formed. The phases of 21. The bonding phases are Mg(OH)2, 5Mg(OH)2.MgC12.8H2O (form 5), 3Mg(OH)2.MgC12.8H2O (form 3), and Mg2(OH)ClCO3«3H2O. Form 5 is the preferred phase because it has superior mechanical properties. Compared 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 different additives and fibers with good bond strength. It can also receive different types of surface treatments. MOC develops high compressive strength within 48 hours, for example, 8000-10000 pounds per square inch (psi). The compressive strength achieved occurs early during curing—at 40 hours, the strength will be at least 80% of the final strength. The compressive strength of MOC is preferably between 40 and 100 N / mm².The tensile and flexural strength is preferably 10-17 N / mm². The surface hardness of MOC is preferably 50-250 N / mm². The E-modulus is preferably 1-3 x 10⁴ N / mm². 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. MOC used in the panel according to the invention can be enriched with one or more of these types of fibers. MOC does not shrink, is abrasion-resistant, and acceptably resistant to wear, impact, chipping, and scratching. MOC resists heat and freeze-thaw cycles and does not require air convection to improve durability.MOC also has excellent thermal conductivity, low electrical conductivity, and excellent bonding to a variety of substrates and additives, and it has acceptable fire resistance properties. MOC is not preferred if the panel will be exposed to extreme climatic conditions (temperature and humidity), which affect both settlement properties and the development of the magnesium oxychloride phase. Over time, carbon dioxide from the atmosphere will react with the magnesium oxychloride to form a surface layer of Mg₂(OH)ClCO₃·3H₂O. This layer slows the leaching process. Eventually, further leaching results in the formation of hydromagnesite, 4MgO·3CO₃·4H₂O, which is insoluble and allows the cement to maintain its structural integrity.Magnesium-based compositions, and in particular magnesia cement, can be used on magnesium sulfate, specifically epsomite heptahydrate of the mineral magnesium sulfate (MgSO4·7H2O). The latter is also known as Epsom salt. In an aqueous solution, MgO reacts with MgSO4, forming magnesium oxysulfate cement. QRzcnn / eznz / e / YiAi (MOS), which has very good bonding properties. In MOS, 5Mg(OH)2.MgSO4.8H2O is the most frequently found chemical phase. Although MOS is not as strong as MOC, it is more suitable for fire-resistant applications because MOS begins to decompose at temperatures more than twice that of MOC, resulting in longer-lasting fire protection. Furthermore, its decomposition products at elevated temperatures are less harmful (sulfur dioxide) than those of oxychloride (hydrochloric acid), and as an aggregate, it is less corrosive. Additionally, climatic conditions (humidity, temperature, and wind) during application are not as critical for MOS as they are for MOC. The mechanical strength of MOS cement depends primarily on the type and relative content of the cement's crystalline phases.Four basic magnesium salts that can contribute to the mechanical strength of MOS cement have been found to exist in the MgO-MgSO4-H2O ternary system at different temperatures between 30 and 120 degrees Celsius: 5Mg(OH)2-MgSO4-3H2O (phase 513), 3Mg(OH)2MgSO4-8H2O (phase 318), Mg(OH)2-2MgSO4-3H2O (phase 123), and Mg(OH)2-MgSO4-5H2O (phase 115). Typically, phase 513 and phase 318 can only be obtained by curing cement under saturated steam conditions when the molar ratio of MgO to MgSO4 is set at (approximately) 5:1. Phase 318 has been found to contribute significantly to mechanical strength and is stable at room temperature, and is therefore preferred in MOS applications. This also applies to phase 513. Phase 513 typically has a (micro)structure comprising an acicular-type structure. This can be verified by SEM analysis.Essentially uniform needles of magnesium oxysulfate (5Mg(OH)2MgSO4·3H2O) can be formed, typically 10–15 pm long and 0.4–1.0 pm in diameter. When referring to an acicular-type structure, a flaky and / or whisker-like structure may also be meant. In practice, it does not appear feasible to obtain MOS comprising more than 50% of phase 513 or 318, but adjustments to the crystalline phase composition can be applied to improve the mechanical strength of the 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 with sufficient mechanical strength for use in the core layer of a floor panel.The crystalline phase of MOS is adjustable by modifying MOS with an organic acid, preferably citric acid and / or phosphoric acid and / or phosphates. During this modification, new MOS phases 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 23. QRzcnn / eznz / e / YiAi MOS with the use of citric acid. Phase 517 can be obtained by modifying MOS with the use of phosphoric acid and / or phosphates (H3PO4, KH2PO4, K3PO4, 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 acicular crystal type and they are insoluble in water. In particular, the compressive strength and water resistance of MOS can be improved with 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 noted above, the addition of phosphoric acid and phosphates can extend the parameter setting time and improve the compressive strength and water resistance of MOS cement by modifying the MgO hydration process and phase composition.Here, phosphoric acid or phosphates ionize in solution to form H₂PO₄⁻, HPO₄²⁻, and / or PO₄³⁻, where these anions adsorb onto [Mg(OH)(H₂O)ₓ]⁺ to inhibit the formation of Mg(OH)₂ and further promote the generation of a new subsulfate phase, resulting in the compact structure, high mechanical strength, and good water resistance of MOS cement. The improvement produced by adding phosphoric acid or phosphates to MOS cement follows the order H₃PO₄ = K₂HPO₄⁻ >> K₂HPO₄ >> K₃PO₄. MOS has better volumetric stability, shrinks less, has better bonding properties, and less co-resistivity over a wider range of climatic conditions than MOC, and is therefore preferred over MOS. The density of MOS typically ranges from 350 to 650 kg / m³. The tensile strength is preferably 1-7 N / mm2. The magnesium cement composition preferably comprises one or more silicone-based additives. Various silicone-based additives may be used, including, but not limited to, silicone oils, neutral-cure silicones, silanols, silanol liquids, silicone (micro)spheres, and mixtures and derivatives thereof. Silicone oils include siloxanes polymerized with organic side chains, including, but not limited to, polymethylsiloxane and its derivatives. Neutral-cure silicones include silicones that release alcohol or other volatile organic compounds (VOCs) during curing. Other silicone-based additives and / or siloxanes (e.g., siloxane polymers) may also be used, including, but not limited to, hydroxyl-terminated (or hydroxy) siloxanes and / or siloxanes terminated with other reactive groups, acrylic siloxanes, urethane siloxanes, epoxy siloxanes, and mixtures and derivatives thereof.As detailed below, one or more crosslinking agents (e.g., silicone-based crosslinking agents) may also be used. The viscosity of one or more silicone-based additives (e.g., silicone oil, neutral-cure silicones, silanol liquid, siloxane polymers, etc.) may be 24. QRzcnn / eznz / e / YiAi around 100 cSt (at 25 °C), which is referred to as low viscosity. In alternative embodiments, the viscosity of one or more silicone-based additives (e.g., silicone oil, neutral-cure silicones, silanol liquid, siloxane polymers, etc.) is between around 20 cSt (25 °C) and around 2000 cSt (25 °C). In other embodiments, the viscosity of one or more silicone-based additives (e.g., silicone oil, neutral-cure silicones, silanol liquid, siloxane polymers, etc.) is between around 100 cSt (25 °C) and around 1250 cSt (25 °C). In other embodiments, the viscosity of one or more silicone-based additives (e.g., silicone oil, neutral-cure silicones, silanol liquid, siloxane polymers, etc.) is between about 250 cSt (25 °C), and 1000 cSt (25 °C).In still other embodiments, the viscosity of one or more silicone-based additives (e.g., silicone oil, neutral-cure silicones, silanol liquid, siloxane polymers, etc.) is between approximately 400 cSt (25 °C) and 800 cSt (25 °C). And in particular embodiments, the viscosity of one or more silicone-based additives (e.g., silicone oil, neutral-cure silicones, silanol liquid, siloxane polymers, etc.) is between approximately 800 cSt (25 °C) and approximately 1250 cSt (25 °C). One or more silicone-based additives may also be used. For example, in later embodiments, the viscosity of one or more silicone-based additives (e.g., silicone oil, neutral-cure silicones, silanol liquid, siloxane polymers, etc.) is between about 20 cSt (25 °C), and about 200.000 cSt (25 °C), from around 1000 cSt (25 °C), and around 100,000 cSt (25 °C), or from around 80,000 cSt (25 °C), and around 150,000 cSt (25 °C). In other embodiments, the viscosity of one or more silicone-based additives (e.g., silicone oil, neutral-cure silicones, silanol liquid, siloxane polymers, etc.) is between approximately 1000 cSt (25 °C) and approximately 20,000 cSt (25 °C).The viscosity of one or more silicone-based additives (e.g., silicone oil, neutral-curing silicones, silanol liquid, siloxane polymers, etc.) is between approximately 1000 cSt (25 °C) and 80,000 cSt (25 °C), between approximately 50,000 cSt (25 °C) and approximately 100,000 cSt (25 °C), or between approximately 80,000 cSt (25 °C) and approximately 200,000 cSt (25 °C). In still other embodiments, the viscosity of one or more silicone-based additives (e.g., silicone oil, neutral-curing silicones, silanol liquid, siloxane polymers, etc.) is between approximately 20 cSt (25 °C) and 100 cSt (25 °C). Other viscosities may also be used as desired. In a preferred embodiment, the cement composition 25. The magnesium oxychloride cement composition, in particular the magnesium oxychloride cement composition, comprises a single type of silicone-based additive. In other embodiments, a mixture of two or more types of silicone-based additives is used. For example, in some embodiments, the magnesium oxychloride cement composition may include a mixture of one or more silicone oils and neutral-curing silicones. In particular embodiments, the ratio of silicone oil to neutral-curing silicones may be from approximately 1:5 to approximately 5:1 by weight. In other embodiments, the ratio of silicone oil to neutral-curing silicones may be from approximately 1:4 to approximately 4:1 by weight. In still other such embodiments, the ratio of silicone oil to neutral-curing silicones may be from approximately 1:3 to approximately 3:1 by weight.In still other embodiments, the ratio of silicone oil to neutral-cure silicones may be between approximately 1:2 and approximately 2:1 by weight. In other such embodiments, the ratio of silicone oil to neutral-cure silicones may be approximately 1:1 by weight. It is reasonable to assume that one or more crosslinking agents are used in the magnesium cement. In some embodiments, the crosslinking agents are silicone-based crosslinkers. Examples of crosslinking agents include, but are not limited to, methyltrimethoxysilane, methyltriethoxysilane, methyltris(methylethylketoxymino)silane, and mixtures thereof and derivatives. Other crosslinking agents (including other silicone-based crosslinkers) may also be used.In some embodiments, the magnesium oxychloride cement composition comprises one or more silicone-based additives (e.g., one or more silanols and / or silanol liquids) and one or more crosslinking agents. The ratio of one or more silicone-based additives (e.g., silanols and / or silanol liquids) to crosslinking agents may be from approximately 1:20 to approximately 20:1 by weight, from approximately 1:10 to approximately 10:1 by weight, or from approximately 1:1 to approximately 10:1 by weight. Magnesium (oxychloride) cement compositions comprising one or more silicone-based additives may exhibit reduced water sensitivity compared to traditional magnesium (oxychloride) cement compositions. Furthermore, in some embodiments, magnesium (oxychloride) cement compositions comprising one or more silicone-based additives may exhibit little or no water sensitivity. Magnesium (oxychloride) cement compositions comprising one or more silicone-based additives may also exhibit hydrophobic and water-resistant properties. QRzcnn / eznz / e / YiAi Furthermore, magnesium (oxychloride) cement compositions comprising one or more silicone-based additives can exhibit improved curing characteristics. For example, magnesium (oxychloride) cement compositions cure to form various reaction products, including 3Mg(OH)₂.MgCl₂.8H₂O (phase 3) and 5Mg(OH)₂.MgCl₂.8H₂O (phase 5) crystalline structures. In some situations, higher percentages of the 5Mg(OH)₂.MgCl₂.8H₂O (phase 5) crystalline structure are preferred. In such situations, the addition of one or more silicone-based additives to magnesium oxychloride cement compositions can stabilize the curing process, which can increase the yield of the 5Mg(OH)₂.MgCl₂.8H₂O (phase 5) crystalline structure.For example, in some embodiments, magnesium oxychloride compositions comprising one or more silicone-based additives can cure to form crystalline structures with more than 80% of 5Mg(OH)2.MgCl2.8H2O (phase 5). In other embodiments, magnesium oxychloride compositions comprising one or more silicone-based additives can cure to form crystalline structures with more than 85% of 5Mg(OH)2.MgCl2.8H2O (phase 5). In still other embodiments, magnesium oxychloride compositions comprising one or more silicone-based additives can cure to form crystalline structures with more than 90% of 5Mg(OH)2.MgCl2.8H2O (phase 5). In still other embodiments, magnesium oxychloride compositions comprising one or more silicone-based additives can cure to form crystalline structures with more than 95% of 5Mg(OH)2.MgCl2.8H2O (phase 5).In still other embodiments, magnesium oxychloride compositions comprising one or more silicone-based additives can cure to form crystalline structures with more than 98% of 5Mg(OH)2.MgCl2.8H2O (phase 5). In still other embodiments, magnesium oxychloride compositions comprising one or more silicone-based additives can cure to form crystalline structures with approximately 100% of 5Mg(OH)2.MgCl2.8H2O (phase 5). Furthermore, magnesium (oxychloride) cement compositions comprising one or more silicone-based additives may also exhibit increased strength and enhanced bonding characteristics. If desired, magnesium (oxychloride) cement compositions comprising one or more silicone-based additives can also be used to manufacture relatively thin magnesium (oxychloride) cement or concrete structures. For example, magnesium (oxychloride) cement compositions comprising one or more silicone-based additives can be used to manufacture cement or concrete structures or layers less than 8 mm thick, preferably less than 6 mm. To achieve interlocking between the interlocking piece, a temporary deformation of part(s) 27 may be desirable and / or even required. QRzcnn / eznz / e / YiAi of interlocking as a result of which it is advantageous to mix magnesium oxide and / or magnesium hydroxide and / or magnesium chloride and / or magnesium sulfate with one or more silicone-based additives, since this results in a greater degree of flexibility and / or elasticity. For example, in some embodiments, cement and concrete structures formed using magnesium oxychloride cement compositions can be bent or banded without cracking or breaking. Magnesium (oxychloride) cement compositions comprising one or more silicone-based additives may further comprise one or more additional additives. These additional additives can be used to enhance particular characteristics of the composition. For example, in some embodiments, the additional additives can be used to give structures formed using the magnesium oxychloride cement compositions the appearance of stone (e.g., granite, marble, sandstone, etc.). In particular embodiments, the additional additives may include one or more pigments or colorants.In other embodiments, additional additives may include fibers, including but not limited to paper fibers, wood fibers, polymer fibers, organic fibers, and glass fiber. Magnesium oxychloride cement compositions may also form UV-stable structures, so that the color and / or appearance are not subject to substantial fading by UV light over time. Other additives may also be included in the composition, including but not limited to plasticizers (e.g., polycarboxylic acid plasticizers, polycarboxylate ether-based plasticizers, etc.), surfactants, water, and mixtures and combinations thereof. As indicated, the magnesium oxychloride cement composition, if applicable, may comprise magnesium oxide (MgO), aqueous magnesium chloride (MgCl₂(aq)), and one or more silicone-based additives.Instead of aqueous magnesium chloride (MgCl₂), magnesium chloride powder (MgCl₂) can also be used. For example, magnesium chloride powder (MgCl₂) can be used in combination with an amount of water that is equivalent to, or otherwise analogous to, the amount of aqueous magnesium chloride (MgCl₂(aq)) added. In certain embodiments, the ratio of magnesium oxide (MgO) to aqueous magnesium chloride (MgCl₂(aq)), if used, can vary in the composition of magnesium oxychloride cement. In some such embodiments, the ratio of magnesium oxide (MgO) to aqueous magnesium chloride (MgCl₂(aq)) is between approximately 0.3:1 and approximately 1.2:1 by weight. In other embodiments, the ratio of magnesium oxide (MgO) to aqueous magnesium chloride (MgCl2(aq)) is between approximately 0.4:1 and approximately 1.2:1 by weight. And in still other embodiments, the ratio of oxide of 28. The ratio of magnesium oxide (MgO) to aqueous magnesium chloride (MgCl2(aq)) to magnesium oxide cement is between approximately 0.5:1 and approximately 1.2:1 by weight. Aqueous magnesium chloride (MgCl2(aq)) can be described as (or otherwise derived from) a magnesium chloride brine solution. Aqueous magnesium chloride (MgCl2(aq)) (or magnesium chloride brine) may also include small amounts of other components and substances, including, but not limited to, magnesium sulfate, magnesium phosphate, hydrochloric acid, phosphoric acid, etc. In a preferred embodiment, the amount of one or more (liquid) silicone-based additives within the magnesium oxychloride cement composition can be defined as the ratio of silicone-based additives to magnesium oxide (MgO). For example, in some embodiments, the weight ratio of silicone-based additives and magnesium oxide (MgO) is between 0.06 and 0.6. Ideally, and even more conveniently, the core layer should incorporate at least one oil, such as linseed oil or silicone oil. This gives the magnesium-based core layer, or the thermoplastic-based core layer, greater flexibility and reduces the risk of breakage. Alternatively, or as an addition to oil, one or more water-soluble polymers or polycondensed (synthetic) resins, such as polycarboxylic acid, can also be incorporated into the core layer. This has the advantage that the panel will not shrink during drying / curing / setting, preventing cracks from forming. Furthermore, after drying / curing / setting, the core layer becomes more hydrophobic, preventing water (moisture) penetration during subsequent storage and use. It is assumed that the core layer comprises polycaprolactone (PCL). This biodegradable polymer is particularly preferred because it has been found to melt the exothermic reaction mixture. It has a melting point of approximately 60°C. PCL can be either low-density or high-density. The latter is especially preferred as it produces a stronger core layer. Instead of, or as an additive to, other polymers may be used, preferably a polymer selected from the group consisting of: other poly(lactic-co-glycolic acid) (PLGA), poly(lactic acid) (PLA), poly(glycolic acid) (PGA), the polyhydroxyalkanoate (PHA) family, polyethylene glycol (PEG), polypropylene glycol (PPG), polyesteramide (PEA), poly(lactic-co-caprolactone), poly(lactide-co-trimethylene carbonate), poly(sebacic acid-co-ricinoleic acid), and a combination thereof. Alternatively, the panel, particularly the core layer, can at least partially be made of PVC, PET, PP, PS, or polyurethane (thermoplastic) (PUR). PS can be in the form of expanded polystyrene (EPS) to further reduce panel density, thus contributing to cost savings.29 QRzcnn / eznz / e / YiAi and facilitates the handling of the panels. Preferably, at least a fraction of the polymer used may be made of recycled thermoplastic, such as recycled PVC or recycled PUR. Recycled PUR may be prepared from recyclable polymers, such as those based on recyclable PET. PET may be chemically recycled by glycolysis or depolymerization of PET into monomers or oligomers, and subsequently into polyurethane polyols. It is also conceivable that rubber and / or elastomeric (particle) parts are dispersed within at least one composite layer to improve flexibility and / or impact resistance to some extent. It is conceivable that a mixture of virgin material and recycled thermoplastic may be used to make up at least a portion of the core. Preferably, in this mixture, the virgin thermoplastic material and the recycled thermoplastic material are essentially the same.For example, such a mixture may be entirely PVC-based or entirely PUR-based. The core (layer) may be solid or agglomerated, or both if the core is composed of a plurality of parts / layers. This may be advantageous if the core layer comprises porous granules, particularly porous ceramic granules. Preferably, the granules have multiple micropores with an average diameter of between 1 and 10 microns, preferably between 4 and 5 microns. That is, the individual granules preferably contain micropores. Preferably, the micropores are interconnected. Preferably, they are not confined to the surface of the granules but are found primarily through the cross-sections of the granules. Preferably, the granule size is between 200 and 900 microns, preferably between 250 and 850 microns, especially between 250 and 500 microns or between 500 and 850 microns. The granules may be substantially the same size or of two or more predetermined sizes.Alternatively, two or more different size ranges can be used with a variety of different-sized particles within each range. Preferably, two different sizes or different size ranges can be used. Preferably, the granules each comprise a plurality of microparticles, substantially each microparticle being partially bonded to one or more adjacent microparticles to define a lattice that defines the micropores. Each microparticle has an average size of 1 to 10 microns, with an average of 4 to 5 microns. Preferably, the average size of the micropores is between 2 and 8 microns, more preferably between 4 and 6 microns. The micropores can be irregularly shaped. Similarly, the size of the micropores, and indeed the midipores discussed below, is determined by summing the diameters of the widest particles. QRzcnn / eznz / e / YiAi of the pore to the narrowest pore diameter and dividing by 2. Preferably, the ceramic material is evenly distributed across a cross-section of the core layer, which is substantially free of agglomerations of the ceramic material forming it. Preferably, the microparticles have an average size of at least 2 microns or 4 microns and / or less than 10 microns or less than 6 microns, more preferably 5 to 6 microns. This particle size range has been found to allow for controlled micropore formation. The granules may also comprise a plurality of substantially spherical midipores having an average diameter of between 10 and 100 microns. These essentially increase the overall porosity of the ceramic material without compromising its mechanical strength. The midipores are preferably interconnected by multiple micropores. That is, the midipores may be fluidly connected to each other through micropores. The average porosity of the ceramic material itself is preferably at least 50%, more preferably 60%, and more preferably between 70 and 75%. The ceramic material used to produce the granules may be any (non-toxic) ceramic material known in the art, such as calcium phosphate and glass ceramics.The ceramic may be a silicate, although it is preferably a calcium phosphate, especially alpha- or beta-tricalcium phosphate or hydroxyapatite, or mixtures thereof. Most preferably, the mixture is hydroxyapatite and beta-tricalcium phosphate, especially more than 50% w / w (m / w) beta-tricalcium phosphate, and more preferably 85% w / w (m / w) beta-tricalcium phosphate and 15% hydroxyapatite. Most preferably, the material is 100% hydroxyapatite. Preferably, the cement or dry premix composition comprises between 15 and 30% by weight of granules of the total dry weight of the composition or premix. Porous particles can lead to a lower average density of the core layer and therefore a reduction in weight, which is advantageous from both an economic and handling perspective. Furthermore, the presence of porous particles in the core layer generally results in, at least to some extent, increased porosity of both the upper and lower porous surfaces of the core layer. This is advantageous for adding an additional layer to the upper and / or lower surface of the core layer, such as a primer, an adhesive (initially liquid), or another decorative or functional layer. Often, these layers are initially applied in a liquid state, where the pores allow the liquid substance to be absorbed (permeate) within them, increasing the surface area of ​​contact between the layers and thus increasing the bond strength between them.31 QRzcnn / eznz / e / YiAi layers. Although most decorative panels according to the invention will be square or rectangular, it is also conceivable that the panel according to the invention may have another shape (viewed from above), such as a hexagonal, octagonal, rhomboid, or parallelogram shape. Preferably, the thickness of the panel is in the range of 3.0 mm to 20.0 mm, and more preferably in the range of 4.0 mm to 12.0 mm. The panel according to the invention may be rigid, semi-rigid, or flexible. Generally, the panels will have at least a degree of resilience to allow the interlocking piece to fit and to achieve (and maintain) the desired tensile strength. The invention also relates to a decorative covering for a floor, ceiling or wall, which is made up of multiple interconnected decorative panels according to the invention. The following set of non-limiting clauses describes other ways of carrying out the invention. Clauses 1. A decorative panel, in particular a floor panel, a wall panel, or a ceiling panel, comprising, at least on a first pair of opposite edges, a first interlocking piece and a second interlocking piece that allow several of said panels to be coupled together, wherein said interlocking pieces, in the coupled state of two of said panels, provide a locking mechanism in a first direction (R1) perpendicular to the plane of the panels, as well as in a second direction (R2) perpendicular to the respective edges and parallel to the plane of the panels, wherein said first interlocking piece comprises a side tongue, and said side tongue comprises a front region and a rear region, wherein a lower surface and / or a side surface of said front region is at least partially rounded,where an upper surface of the front region is inclined at least partially downwards in the opposite direction to the rear region and where a lower and / or lateral surface of the rear region of said side tab defines a first contact portion, and where the side tab comprises a passive lower surface situated adjacent to the first contact portion, where said passive lower surface is defined by a portion cut out on a lower side of the side tab where said second interlocking piece comprises a recess for accommodating at least a portion of the side tab of another panel, said recess being defined by an upper lip and a lower lip, where the lower lip extends beyond the upper lip, and where the lower lip is provided with an upwardly projecting shoulder that defines a second contact portion 32, QRzcnn / eznz / e / YiAi configured to actively co-act with said first contact portion of another panel, in the coupled state of said panels, such that the panels are forced with a tensile force (TI) at least laterally towards each other, wherein an upper surface of said lower lip is at least partially gently curved and is configured as a sliding surface for the lower surface that is at least partially rounded and / or the lateral surface of the front region of the side tab of another panel during coupling, and wherein said at least partially curved upper surface of the lower lip and said passive lower surface of the side tab are mutually situated such that, in the coupled state of two panels, there is an intermediate space adjacent to the first and second actively co-acting contact portions,and where a lower surface of the upper lip is at least partially inclined and configured to splice with at least a portion of the upper surface of the front region of the side tab of another panel. 2. The panel in accordance with clause 1, wherein the passive lower surface of the side tab is substantially flat. 3. The panel in accordance with clause 1 or 2, wherein the passive lower surface is at least partially inclined downwards in the direction of the front region. 4. The panel in accordance with clause 3, wherein the inclined upper surface of the side tongue and the inclined passive lower surface converge in a direction away from the rear region of the side tongue. 5. The panel in accordance with one of the preceding clauses, wherein the upper surface of the lower lip defines a deeper point of the inlet, and wherein, in the coupled state of two panels, said deeper point is located at a distance from the passive lower surface. 6. The panel according to any of the preceding clauses, wherein the upper surface of the lower lip defines a deeper point of the recess where the shoulder of the lower lip defines a higher point of the lower lip, wherein said deeper point and said higher point define a lower lip depth (LLD), and wherein the first and second contact portions are situated entirely above half the lower lip depth. 7. The panel according to any of the preceding clauses, wherein the upper surface of the lower lip defines a deeper point of the recess where the shoulder of the lower lip defines a higher point of the lower lip, wherein said deeper point and said higher point define a lower lip depth (LLD), and wherein the minimum thickness (STD) of the side tongue, measured between the at least partially inclined upper surface and the passive lower surface 33 QRzcnn / eznz / e / YiAi of the lateral tongue exceeds the depth of the lower lip. 8. The panel according to one of the preceding clauses, wherein the first contact portion is inclined upwards in a direction away from the front region of the side tab, wherein the first inclined contact portion and the plane of the panel preferably enclose an angle of at least 45 degrees, and wherein the second contact portion is inclined upwards in a direction away from the upper lip, wherein the second inclined contact portion and the plane of the panel preferably enclose an angle of at least 45 degrees. 9. The panel in accordance with one of the above clauses, wherein the first contact portion and the second contact portion extend in a substantially parallel direction. 10. The panel in accordance with one of the preceding clauses, wherein the lower surface and / or the side surface of the front region of the side tab is configured to coerce the lower lip in the coupled state of two panels, and together define a lower front contact surface. 11. The panel in accordance with clause 10, wherein the entire lower front contact surface is situated below the level of the first and second contact portions. 12. The panel according to clause 10 or 11, wherein the lower front contact surface on one side and the contact surface defined by the first and second contact portions on the other side mutually enclose an angle of between 70 and 110 degrees, preferably between 80 and 100 degrees. 13. The panel in accordance with one of the preceding clauses, wherein a seam formed by two interlocking panels defines a vertical plane (VP), wherein said vertical plane subdivides the lower lip into an inner part of the lower lip and an outer part of the lower lip. 14. The panel in accordance with one of clauses 10-12 and clause 13, wherein at least a portion of the lower front contact surface, preferably the entire lower front contact surface, and the first and second contact portions are situated on the same side of the vertical plane. 15. The panel in accordance with clause 13 or 14, in which the upper surface of the front region of the side tab intersects the vertical plane (VP). 16. The panel in accordance with one of clauses 13-15, wherein the entire upper surface of the lower tongue extending between said vertical plane (VP) and the second contact portion is a smooth curved surface. 17. The panel in accordance with one of the preceding clauses, in which the upper surface of the 34 QAzcnn / eznz / e / YiAi The lower lip is provided with a stepped cut-out portion, which is at least partially located below the upper lip, and which is configured to accommodate a terminal portion of the side tab of another panel. 18. The panel according to clause 17, wherein the upper lip and the stepped cutout portion of the lower lip are configured to engage the terminal portion of the side tab. 19. The panel according to one of clauses 17-18, wherein the stepped cutout portion is fully positioned beneath the upper lip. 20. The panel in accordance with one of the preceding clauses, wherein the panel defines an upper surface and a lower surface that define the panel thickness (PT), and wherein the shoulder thickness (ST), measured from the lower surface of the panel to the highest point of the shoulder, exceeds 30%, preferably 50%, of the panel thickness (PT). 21. The panel in accordance with one of the preceding clauses, wherein, in the coupled state of the panels, an upper shoulder surface is located at a distance from a facing lower surface of the first interlocking piece. 22. The panel in accordance with one of the preceding clauses, wherein an upper shoulder surface is substantially parallel to the plane of the panel. 23. The panel in accordance with one of the preceding clauses, wherein a seam formed by or between two panels in the coupled state defines a vertical plane (VP), wherein said vertical plane subdivides the lower lip into an inner part of the lower lip and an outer part of the lower lip, and wherein, in the coupled state, the entire lower surface and the entire side surface of the inner part of the lower lip are located at a distance from the second interlocking piece. 24. The panel in accordance with one of the preceding clauses, in which the lower lip is entirely situated below the upper lip. 25. The panel in accordance with one of the above clauses, wherein the upper surface of the front region of the side tab and a side surface of the front region of the side tab are connected by a convex transition surface. 26. The panel in accordance with one of the above clauses, where the lower surface of the upper lip and a lateral surface of the upper lip are connected by a convex transition surface. 27. The panel in accordance with one of the preceding clauses, wherein the first interlocking piece and the second interlocking piece are also provided for at least a second pair of opposite edges. 28. The panel according to one of the preceding clauses, wherein the panel comprises, at least on another pair of opposite edges, in particular the second, a third interlocking piece and a fourth interlocking piece that allow several of said panels to be assembled together by a downward or vertical movement, wherein said interlocking pieces, in the coupled state of two of said panels, provide a locking mechanism in a first direction (R1) perpendicular to the plane of the panels, as well as in a second direction (R2) perpendicular to the respective edges and parallel to the plane of the panels, wherein the third interlocking piece comprises a rising tongue, at least one rising flank located at a distance from the rising tongue, and a rising groove formed between the rising tongue and the rising flank,where the ascending groove is adapted to receive at least a portion of a descending tongue of the fourth interlocking piece of another panel, where the side of the ascending tongue facing the ascending flank is the inside of the ascending tongue and the side of the ascending tongue facing the outside of the ascending flank is the outside of the ascending tongue, wherein the fourth interlocking piece comprises a descending tongue, at least one descending flank located at a distance from the descending tongue, and a descending groove formed between the descending tongue and the descending flank, wherein the descending groove is adapted to receive at least a portion of the ascending tongue of the third interlocking piece of another panel,where the side of the descending tongue facing the descending flank is the inside of the descending tongue and the side of the descending tongue facing away from the descending flank is the outside of the descending tongue. 29. The panel according to clause 28, wherein the interior of the rising tab and the interior are configured to coerce with the interior of the descending tab of another panel, in the coupled state of said panels, such that the panels are forced with a tensile force (T2) at least laterally towards each other. 30. The panel in accordance with clause 28 or 29, wherein at least a portion of the inside of the rising tab is inclined towards the rising flank, and wherein at least a portion of the inside of the falling tab is inclined towards the falling flank, allowing the locking of two panels in the first direction (Rl). 31. The panel in accordance with one of clauses 28-30, wherein the exterior of the rising tab is provided with a first locking element, and wherein the descending flank is provided with a second locking element configured for coercion with the first element 36 QRzcnn / eznz / e / YiAi of blocking another panel, allowing two panels to be locked in the first direction (Rl). 32. The panel according to clause 31, wherein the first locking element comprises an outward protrusion and the second locking element comprises a recess, wherein the outer portion of the outward protrusion comprises an upper portion and an adjacent lower portion, wherein the lower portion comprises an inclined locking surface and the upper portion comprises a guide surface, preferably curved, wherein said recess comprises an upper portion and an adjacent lower portion, wherein the lower portion comprises an inclined locking surface, wherein, in the coupled state of the adjacent panels, the inclined locking surface of the lower portion of the outward protrusion and the inclined locking surface of the lower portion of the recess are in contact to effect said locking effect between the panels and / or wherein, in the coupled state of the adjacent panels,The upper portions of the first locking element and the second locking element are preferably at least partially separated. 33. The panel in accordance with clause 32, wherein the length of the inclined locking surface of the lower portion of the outward protrusion is greater, preferably at least 1.5 times greater, than the inclined locking surface of the lower portion of the inward protrusion. 34. The panel according to clause 32 or 33, wherein the upper portion extends over a larger vertical section compared to the lower portion, where, preferably, the height of the upper portion is at least three times greater than the height of the lower portion. 35. The panel according to one of clauses 28-34, wherein the rising flank and the outer portion of the falling tongue define substantially vertical upper contact surfaces of the panel, and wherein adjacent to the upper contact surfaces both the falling tongue and the rising flank comprise an inclined contact surface, wherein the inclined contact surface of the falling tongue of said panel is configured to engage the inclined contact surface of the rising flank of an adjacent panel, in the coupled state of said panels, wherein each substantially vertical upper contact surface and each adjacent inclined surface mutually enclose an angle (a) between 100 and 175 degrees. 36. The panel in accordance with one of clauses 28-35, wherein the outer part of the descending tab is provided with a third locking element, and wherein the ascending flank is provided with a fourth locking element configured to coerce the third element of 37 QRzcnn / eznz / e / YiAi blocking another panel, allowing the blocking of two panels in the first direction (Rl). 37. The panel in accordance with clauses 35 and 36, wherein the third locking element is defined at least partially by the upper contact surface of the descending tab, and wherein the fourth locking element is defined at least partially by the upper contact surface of the ascending flank. 38. The panel in accordance with any of the above clauses, wherein at least a part of each of the interlocking pieces forms an integral part of a core layer of the panel. 39. The panel in accordance with any of the preceding clauses, wherein the panel comprises at least one core layer, and at least one decorative top section, fixed directly or indirectly to said core layer, wherein the top section defines a top surface of the panel. 40. The panel in accordance with clause 39, wherein the upper section comprises a printed decorative layer, and at least one wear layer covering said printed decorative layer. 41. The panel according to clause 39 or 40, wherein at least one core layer comprises a moisture-sensitive material, such as wood. 42. The panel in accordance with one of clauses 39-41, wherein at least one core layer is composed, at least partially, of a medium-density fiberboard (MDF) or a high-density fiberboard (HDF). 43. The panel in accordance with one of the above clauses, wherein the panel has a rectangular or hexagonal shape. 44. The panel in accordance with one of the above clauses, wherein the panel has a vertical thickness in the range of 3.0 mm to 20.0 mm, preferably in the range of 4.0 mm to 12.0 mm. 45. The panel in accordance with one of the preceding clauses, in which the upper surface of the lower lip is, for the most part, gently curved according to a substantially constant radius. 46. ​​The panel according to one of the preceding clauses, wherein the upper surface of the lower lip comprises a curved rear upper surface and a curved front upper surface, wherein the rear upper surface and the front upper surface are stepped relative to each other, and wherein preferably the front upper surface is recessed relative to the rear upper surface. 47. The panel in accordance with one of the preceding clauses, wherein the lateral surface of the front region of the side tab and an opposing part of the upper surface of the lower lip have a substantially complementary shape, and preferably a substantially 38 curvature Complementary QRzcnn / eznz / e / YiAi. 48. The panel in accordance with one of the preceding clauses, wherein the maximum distance a between the lateral surface of the front region of the side tab and an opposing part of the upper surface of the lower lip is less than the maximum distance b between the passive lower surface of the side tab and an opposing part of the upper surface of the lower lip. 49. The decorative covering for a floor, ceiling or wall, which is made up of a multitude of interconnected decorative panels in accordance with one of the preceding clauses. The invention will be elucidated on the basis of the non-limiting exemplary embodiments illustrated in the following figures, in which: Figure 1 shows a rectangular floor panel according to the present invention; Figure 2 shows a cross-section along line AA of Figure 1, of the respective side edges; Figure 3 shows a method for assembling the side edges illustrated in Figure 2; Figure 4 shows, in a cross section, the lateral edges of Figure 2 in the coupled state; Figure 5 shows a cross section along line BB of Figure 1 of the respective lateral edges; Figure 6 shows a method of coupling the side edges illustrated in Figure 5; Figure 7 shows, in a longitudinal cross-section, further details of the respective side edges when they are in a coupled state; Figure 8 shows an alternative way of realizing the side edges of Figure 2 that allows another method of coupling; Figure 9 shows another alternative way of realizing the side edges of Figure 2. Figure 1 shows a decorative panel 1 whose upper face 2 is provided with a decorative top layer 12. The panel is rectangular in shape and has a length extending longitudinally along line BB, and a width extending transversely along line AA. The plane of the panel is determined by the combination of lines AA and BB. At opposite lateral edges 3 and 4, there is a first insert in the shape of profile 5, or a second insert in the shape of profile 6. At opposite lateral edges 9 and 10, there is a third insert in the shape of profile 7, or a fourth insert in the shape of profile 8. Figure 2 shows in cross section the first interlocking piece 5 on the lateral edge 3. The first interlocking piece 5 comprises a lateral tab 20 comprising a front region 39 QRzcnn / eznz / e / YiAi and a rear region 22, wherein a lower surface 23 and / or a side surface 23 of said front region 21 is at least partially rounded, wherein an upper surface 24 of the front region 21 is inclined at least partially downwards in the opposite direction to the rear region 22, and wherein a lower surface 26 and / or a side surface 26 of the rear region 22 of said side tab 20 defines a first contact portion 26, and wherein the side tab 20 comprises a passive lower surface 27 located adjacent to the first contact portion 26, wherein said passive lower surface 27 is defined by a portion cut out on a lower side of the side tab 20. The passive lower surface 27 extends over an intermediate region 28 between the rear region 22 and the front region 21, and is substantially flat.The passive lower surface 27 is inclined downwards towards the front region 21, such that the inclined upper surface 24 of the side tab and the inclined passive lower surface 27 converge in a direction away from the rear region of the side tab. Furthermore, the second interlocking piece 6 comprises a recess 30 for accommodating at least a portion of the side tab 20 of another panel, said recess 30 being defined by an upper lip 31 and a lower lip 32, wherein the lower lip 32 extends beyond the upper lip 31, and wherein the lower lip 32 is provided with an upwardly projecting shoulder 33 defining a second contact portion 34 configured to actively engage with a first contact portion 26 of another panel, in the coupled state of such panels, as will be established with reference to Figure 4.An upper surface 35 of the lower lip 32 is gently curved, at least partially, and is configured as a sliding surface for the lower surface 23, which is at least partially rounded, and / or the side surface 23 of the front region 21 of the side tab 20 of another panel during the engagement of the first and second interlocking pieces. The upper surface 35 of the lower lip is provided with a stepped cutout portion 35s, which is located at least partially below the upper lip 31, and which is configured to accommodate a terminal portion of the side tab 20 of another panel. Figure 3 shows a method for coupling two panels 1 and Γ, each of which is provided with a first and a second interlocking piece 5 and 6, as shown in Figure 2. The two panels are coupled together by a tilting movement about arrow MA. As can be seen in Figure 3, the curvature of the upper surface 35 of the lower lip 32 acts as a sliding surface for the lower surface 23, which is at least partially rounded, and / or the side surface 23 of the tab 20. QAzcnn / eznz / e / YiAi Figure 4 shows the interlocking pieces 5 and 6 of the two panels 1 and 1' once the coupling shown in Figure 3 has been completed by tilting. The respective contact portions 26 and 34 in the coupled state shown, together create a tensile force (TI) that forces the side edges 3 and 4 towards each other. Furthermore, in the engaged state shown, the at least partially curved upper surface 35 of the lower lip 32 and the passive lower surface 27 of the side tab 20 are positioned such that an intermediate space S is present adjacent to the actively acting contact portions 26 and 34. The passive lower surface 27 is represented as substantially flat, but may alternatively have a concave or convex surface, provided that an amount of intermediate space S is maintained between the tab and the inlet in the engaged state. A lower surface 36 of the upper lip 31 is at least partially inclined and configured to abut at least a portion of the upper surface 24 of the front region of the side tab 20.The upper surface 35 of the lower lip defines a deepest point 38 of the recess, where the shoulder 33 of the lower lip defines a highest point 39 of the lower lip, and where said deepest point and said highest point define a lower lip depth (LLD). On the upper face of panels 1 and Γ, which are forced together by the tensile force of the contact portions 26 and 34, there is a seam 40 that defines a vertical plane VP which subdivides the lower lip 32 into an inner lower lip portion 32i and an outer lower lip portion 32o. The upper surface of the shoulder portion 33 is here located at a distance from the first mating portion 5, so that an intermediate space is also present in this portion. Figure 5 shows a longitudinal cross-section of panel 1 shown in Figure 1, along line BB. At the side edges 9 and 10, there is a third interlocking piece in the form of profile 7 respectively. A fourth interlocking profile is in the form of profile 8. The third interlocking piece 7 comprises a rising tongue 71, a rising flank 72 located at a distance from the rising tongue, and a rising groove 73 formed between the rising tongue 71 and the rising flank 72, where the rising groove is adapted to receive at least a portion of a falling tongue 81 from the fourth coupling element 8 of another panel. The side of the ascending tongue 71 that faces the ascending flank 72 is the inside 77 of the ascending tongue, and the side of the ascending tongue 71 that faces away from the ascending flank 72 is the outside 76 of the ascending tongue.A first locking element 75 is provided on an outer side of the ascending tongue 71 that extends away from the ascending flank 72. The fourth locking piece 8 comprises a descending tongue 81, a descending flank 82 located at a distance from 41. QRzcnn / eznz / e / YiAi descending tongue, and a descending groove 83 formed between the descending tongue 81 and the descending flank 82, wherein the descending groove 83 is adapted to receive at least a portion of the ascending tongue 71 of the third interlocking piece 7 of another panel. The side of the descending tongue 81 that faces the descending flank 82 is the inside 87 of the descending tongue and the side of the descending tongue 81 that faces away from the descending flank 82 is the outside 86 of the descending tongue 81. A second locking element 85 adapted for coercion with a first locking element 75 of another panel is provided on the descending flank 82. Figure 6 shows how the third and fourth interlocking profiles 7 and 8 of Figure 5 can be coupled together by connecting a panel 1 and a panel 1'. Panel 1' is moved vertically downwards along the arrow, where profiles 7 and 8 are coupled together by receiving the upward tongue 71 in the downward groove 83 and receiving the downward tongue 81 in the upward groove 73. Figure 7 shows in more detail the side edges 7 and 8 in the coupled state, after the vertical movement coupling has been completed as shown in Figure 6. It can be seen that the side edges 7 and 8 of the embodiment in Figure 7 contain some slight adaptations compared to the embodiment illustrated in Figures 5 and 6, which are directly visible from the figures and are explained later. Since Figures 5-7 share the same features, these are indicated by the same reference numbers. The inner part 77 of the rising tab 71 is in contact with the inner part 87 of the descending tab 81 of another panel, such that the panels create a tensile force (T2) that forces the side edges 7 and 8 closer together.A portion of the interior 77 of the rising tongue is inclined towards the rising flank 72, and a portion of the interior 87 of the descending tongue 81 is inclined towards the descending flank 82, such that the two mating panels interlock in a direction perpendicular to the plane of the panels (i.e., in a vertical direction). Furthermore, the first and second locking elements 75 and 85 interlock with each other, further contributing to the vertical interlocking of the mating panels. The first locking element is a protrusion 75, and the second locking element is a recess 85. The protrusion 75 has an upper portion 90 and an adjacent lower portion 88, wherein the lower portion 88 comprises an inclined locking surface and the upper portion 90 comprises a guide surface, preferably curved.The inlet 85 comprises an upper portion 94 and an adjacent lower portion 92, wherein the lower portion 92 comprises an inclined locking surface. QRzcnn / eznz / e / YiAi The respective upper portions 90 and 94 are spaced apart, thus allowing for an intermediate gap. At the top of the coupled side edges 7 and 8, the upper contact surfaces 95 and 96 are forced together due to the interaction of the inner parts 77 and 87. Furthermore, the respective upper contact surfaces 95 and 96 are provided with a protrusion 98 and a recess 97, which interlock with each other in the coupled state. Above the protrusion 98 and the recess 97 are provided the respective inclined contact surfaces 99a and 99b, which couple with each other. Figure 8 shows an alternative embodiment of the side edges 3 and 4 according to Figure 2, wherein the upper surface 24 of the front region 21 of the side tab and a side surface 23 of the front region 21 of the side tab are connected by a transient convex surface 100, and the lower surface 36 of the upper lip 31 and a side surface 102 of the upper lip 31 are connected by a transient convex surface 104. All other features of the side edges 3 and 4 are similar to Figure 2. The illustrated embodiment allows for a snapping movement by sliding the panels toward each other in a planar direction as indicated by the "Snap" arrow. Figure 9 shows an alternative embodiment of the lateral edges 3 and 4 according to Figure 2, wherein the upper surface 35 of the lower lip 32 has a stepped, cut-out portion 35s that is complementary in size to the terminal portion 23 of the tab 20, so that it encloses portion 23 in a clasp-like fashion. All other features of the lateral edges 3 and 4 are similar to those in Figure 2. The concepts of the invention described above have been illustrated by various embodiments. It is conceivable that individual concepts of the invention may be applied without also applying other details of the described example. It is not necessary to provide examples of all conceivable combinations of the concepts of the invention described above, since a person skilled in the art will understand that numerous concepts of an invention may be (re)combined to achieve a specific application. It will be evident that the invention is not limited to the examples of operation shown and described herein, but that numerous variations are possible within the scope of the attached claims, which will be obvious to those skilled in the art. The verb "comprender" and its conjugations as used in this patent publication are understood not only as "to understand," but also as "to contain," "to consist substantially of," "formed by," and its conjugations.

Claims

1. The decorative panel, in particular a floor panel, wall panel, or ceiling panel, comprising, at least on a first pair of opposite edges, a first interlocking piece and a second interlocking piece that allows several such panels to be coupled together, wherein these interlocking pieces, in the coupled state of two of said panels, provide a locking mechanism in a first direction (R1) perpendicular to the plane of the panels, as well as in a second direction (R2) perpendicular to the respective edges and parallel to the plane of the panels, wherein said first interlocking piece comprises a side tongue, wherein said side tongue comprises a front region and a rear region, wherein a lower surface and / or a side surface of said front region are at least partially rounded,wherein an upper surface of the front region is at least partially inclined downwards in a direction opposite to the rear region, and wherein a lower and / or side surface of the rear region of said side tab defines a first contact portion, and wherein the side tab comprises a passive lower surface located adjacent to the first contact portion, wherein said passive lower surface is defined by a portion cut out on a lower side of the side tab, wherein said second interlocking piece comprises a recess for accommodating at least a portion of the side tab of another panel, said recess being defined by an upper lip and a lower lip, wherein the lower lip extends beyond the upper lip,and wherein the lower lip is provided with an upwardly projecting shoulder that defines a second contact portion configured to actively co-act with said first contact portion of another panel, in the coupled state of said panels, such that the panels are forced with a tensile force (TI) at least laterally toward one another, wherein an upper surface of said lower lip is at least partially gently curved and is configured as a sliding surface for the lower surface that is at least partially rounded and / or the lateral surface of the front region of the side tab of another panel during assembly, and wherein said at least partially curved upper surface of the lower lip and said passive lower surface of the side tab are mutually positioned such that, in the coupled state of two panels,An intermediate space is presented adjacent to the first and second actively co-acting contact portions, and where a lower surface of the upper lip is at least partially inclined and configured to splice with at least a portion of the upper surface of the front region of the side tab of another panel, wherein the lower surface and / or the 44 QRzcnn / eznz / e / YiAi side surface of the front region of the side tab are configured to co-act with the lower lip in the coupled state of two panels, and together define a lower front contact surface, wherein a seam formed by two panels in the coupled state defines a vertical plane (VP), wherein said vertical plane subdivides the lower lip into an inner portion of the lower lip and a lower outer portion of the lower lip,and wherein the entire lower front contact surface and the first and second contact portions are located on the same side of the vertical plane.

2. The panel according to claim 1, wherein the passive lower surface of the side tab is substantially flat.

3. The panel according to claim 1 or 2, wherein the passive lower surface is at least partially inclined downwards in a direction towards the front region.

4. The panel according to claim 3, wherein the inclined upper surface of the side tab and the inclined passive lower surface converge in a direction opposite to the rear region of the side tab.

5. The panel according to one of the preceding claims, wherein the upper surface of the lower lip defines a deeper point of the recess, and wherein, in the coupled state of two panels, said deeper point is located at a distance from the passive lower surface.

6. The panel according to one of the preceding claims, wherein the upper surface of the lower lip defines a deeper point of the recess, wherein the shoulder of the lower lip defines a higher point of the lower lip, wherein said deeper point and said higher point define a lower lip depth (LLD), and wherein the first and second contact portions are fully located above half the lower lip depth.

7. The panel according to one of the preceding claims, wherein the upper surface of the lower lip defines a deeper point of the recess, wherein the shoulder of the lower lip defines a higher point of the lower lip, wherein said deeper point and said higher point define a lower lip depth (LLD), and wherein the smaller thickness (STD) of the side tab, measured between the at least partially inclined upper surface and the passive lower surface of the side tab, exceeds the lower lip depth.

8. The panel according to one of the preceding claims, wherein the first contact portion is inclined upwards in a direction opposite to the front region of the side tab, wherein the first inclined contact portion and the plane of the panel preferably enclose an angle of at least 45 degrees, and wherein the second contact portion is inclined upwards in a direction opposite to the upper lip, wherein the second inclined contact portion and the plane of the panel preferably enclose an angle of at least 45 degrees.

9. The panel according to one of the preceding claims, wherein the first contact portion and the second contact portion extend in a substantially parallel direction.

10. The panel according to one of the preceding claims, wherein the substantially complete upper surface of the lower lip is smoothly curved according to a substantially constant radius.

11. The panel according to one of the preceding claims, wherein the upper surface of the lower lip comprises a curved rear upper surface and a curved front upper surface, wherein the rear upper surface and the front upper surface are stepped relative to each other, and wherein preferably the front upper surface is recessed relative to the rear upper surface.

12. The panel according to one of the preceding claims, wherein the entire lower front contact surface is located below the level of the first and second contact portions.

13. The panel according to one of the preceding claims, wherein the lower front contact surface on one side and the contact surface defined by the first and second contact portions on the other side form an angle between 70 and 110 degrees, preferably between 80 and 100 degrees.

14. The panel according to one of the preceding claims, wherein the side surface of the front region of the side tab and an opposing part of the upper surface of the lower lip have a substantially complementary shape, and preferably substantially complementary curves.

15. The panel according to one of the preceding claims, wherein the upper surface of the front region of the side tab intersects the vertical plane (VP).

16. The panel according to one of the preceding claims, wherein the entire upper surface of the lower lip extending between said vertical plane (VP) and the second contact portion is a smooth curved surface.

17. The panel according to one of the preceding claims, wherein the upper surface of the lower lip is provided with a stepped cut-out portion, which is located at least partially below the upper lip, and which is configured to accommodate a terminal portion of the side tab of another panel.

18. The panel according to claim 17, wherein the upper lip and the stepped cut-out portion of the lower lip are configured to hold the terminal portion of the side tab.

19. The panel according to one of claims 17-18, wherein the stepped cut-out portion is positioned completely below the upper lip.

20. The panel according to one of the preceding claims, wherein the panel defines an upper surface and a lower surface that define the thickness (PT) of the panel, and wherein the shoulder thickness (ST), measured from the lower surface of the panel to the highest point of the shoulder, exceeds 30%, preferably 50%, of the panel thickness (PT).

21. The panel according to one of the preceding claims, wherein, in the coupled state 47 QRzcnn / eznz / e / YiAi of the panels, an upper shoulder surface is positioned at a distance from a facing lower surface of the first interlocking piece.

22. The panel according to one of the preceding claims, wherein an upper shoulder surface is substantially parallel to the plane of the panel.

23. The panel according to one of the preceding claims, wherein a seam formed by or between two panels in the coupled state defines a vertical plane (VP), wherein said vertical plane subdivides the lower lip into an inner lower lip part and an outer lower lower lip part, and wherein, in the coupled state, the entire lower surface and the entire side surface of the inner lower lip part are positioned at a distance from the second interlocking piece.

24. The panel according to one of the preceding claims, wherein the lower lip is entirely below the upper lip.

25. The panel according to one of the preceding claims, wherein the upper surface of the front region of the side tab and a side surface of the front region of the side tab are connected by means of a convex transition surface.

26. The panel according to one of the preceding claims, wherein the lower surface of the upper lip and a lateral surface of the upper lip are connected by means of a convex transition surface.

27. The panel according to one of the preceding claims, wherein the first interlocking piece and the second interlocking piece are also provided at least on a second pair of opposite edges.

28. The panel according to one of the preceding claims, wherein the panel comprises, at least on another pair of opposite edges, in particular the second, a third interlocking piece and a fourth interlocking piece that allows several such panels to be coupled together by a downward or vertical movement, wherein these interlocking pieces, in the coupled state of two of said panels, provide a locking in a first direction (R1) perpendicular to the plane of the panels, as well as in a second direction (R2) perpendicular to the respective edges and parallel to the plane of the panels, wherein the third interlocking piece comprises a rising tongue, at least one rising flank located at a distance from the rising tongue, and a rising groove formed between the rising tongue and the rising flank,wherein the ascending groove is adapted to receive at least a portion of a descending tongue of the fourth interlocking piece of another panel, wherein the side of the ascending tongue facing the ascending flank is the inside of the ascending tongue and the side of the ascending tongue opposite the ascending flank is the outside of the ascending tongue, wherein the fourth interlocking piece comprises a descending tongue, at least one descending flank located at a distance from the descending tongue, and a descending groove formed between the descending tongue and the descending flank, wherein the descending groove is adapted to receive at least a portion of the ascending tongue of the third interlocking piece of another panel,wherein the side of the descending tongue that faces the descending flank is the inside of the descending tongue and the side of the descending tongue that is opposite the descending flank is the outside of the descending tongue.

29. The panel according to claim 28, wherein the interior of the rising tab and the interior are configured to co-act with the interior of the descending tab of another panel, in the coupled state of said panels, so that the panels are forced with a tensile force (T2) at least laterally against each other.

30. The panel according to claim 28 or 29, wherein at least a portion of the interior of the rising tab is inclined towards the rising flank, and wherein at least a portion of the interior of the descending tab is inclined towards the descending flank, allowing two panels to lock together in the first direction (Rl).

31. The panel according to any one of claims 28-30, wherein the exterior of the upper tab is provided with a first locking element, and wherein the lower flank is provided with a second locking element configured to co-act with the first locking element of another panel, enabling two panels to be locked in the first direction (Rl). QRzcnn / eznz / e / YiAi 32. The panel according to claim 31, wherein the first locking element comprises an outward projection and wherein the second locking element comprises a recess, wherein the exterior of the outward projection comprises an upper portion and an adjacent lower portion, wherein the lower portion comprises an inclined locking surface and the upper portion comprises a guide surface, preferably curved, wherein said recess comprises an upper portion and an adjacent lower portion, wherein the lower portion comprises an inclined locking surface, wherein, in the coupled state of adjacent panels, the inclined locking surface of the lower portion of the outward projection and the inclined locking surface of the lower portion of the recess are in contact to effect said locking effect between the panels and / or wherein, in the coupled state of adjacent panels,The upper portions of the first locking element and the second locking element are preferably at least partially separated.

33. The panel according to claim 32, wherein the length of the inclined locking surface of the lower portion of the outward projection is greater, preferably at least 1.5 times greater, than the inclined locking surface of the lower portion of the inward projection.

34. The panel according to claim 32 or 33, wherein the upper portion extends over a larger vertical section compared to the lower portion, wherein, preferably, the height of the upper portion is at least three times the height of the lower portion.

35. The panel according to any one of claims 28-34, wherein the rising flank and the outside of the falling tab define substantially vertical upper contact surfaces of the panel, and wherein adjacent to the upper contact surfaces, both the falling tab and the rising flank comprise an inclined contact, wherein the inclined contact surface of the falling tab of said panel is configured to engage the inclined contact surface of the rising flank of an adjacent panel, in the coupled state of said panels, wherein each substantially vertical upper contact surface and each adjacent inclined surface mutually enclose an angle (a) between 100 and 175 degrees.

36. The panel according to one of claims 28-35, wherein the exterior of the 50 QRzcnn / eznz / e / YiAi downward tab is provided with a third locking element, and wherein the upper flank is provided with a fourth locking element configured to co-act with the third locking element of another panel, enabling two panels to be locked in the first direction (Rl).

37. The panel according to claims 35 and 36, wherein the third locking element is defined at least partially by the upper contact surface of the descending tab, and wherein the fourth locking element is defined at least partially by the upper contact surface of the ascending flank.

38. The panel according to any of the preceding claims, wherein at least a portion of each of the interlocking pieces forms an integral part of a core layer of the panel.

39. The panel according to any of the preceding claims, wherein the panel comprises at least one core layer and at least one decorative top section, fixed directly or indirectly to said core layer, wherein the top section defines an upper surface of the panel.

40. The panel according to claim 39, wherein the upper section comprises a printed decorative layer and at least one wear layer covering said printed decorative layer.

41. The panel according to claim 39 or 40, wherein at least one core layer comprises a moisture-sensitive material, such as wood.

42. The panel according to one of claims 39-41, wherein at least one core layer is composed at least partially of medium density fiberboard (MDF) or high density fiberboard (HDF).

43. The panel according to one of the preceding claims, wherein the panel is rectangular or hexagonal in shape.

44. The panel according to one of the preceding claims, wherein the panel has a vertical thickness in the range of 3.0 mm to 20.0 mm, preferably in the range of 4.0 mm to 12.0 mm.

45. The panel according to one of the preceding claims, wherein the maximum distance a between the lateral surface of the front region of the side tab and an opposing part of the upper surface of the lower lip is less than the maximum distance b between the passive lower surface of the side tab and an opposing part of the upper surface of the lower lip.

46. ​​The decorative covering for a floor, ceiling or wall, which is made up of a multitude of interconnected decorative panels according to one of the preceding claims.