Panel and covering

Abstract

The market for floor coverings has made tremendous progress over the past few decades. Various methods of installing floor panels on subfloors are known. This invention relates to an improved panel, such as a floor panel, particularly a decorative floor panel. This invention also relates to a covering, particularly a floor covering, comprising a plurality of interconnected panels according to the invention.

Description

[Technical Field]

[0001] The present invention relates to a panel, particularly a floor panel, and a covering, particularly a floor covering, comprising a plurality of panels according to the invention. [Previous Technology]

[0002] Over the past few decades, the market for floor coverings has made tremendous progress. Various methods of installing floor panels on a subfloor are known. For example, floor panels are known to be attached to the subfloor by gluing or nailing. The disadvantage of this technique is its complexity, and subsequent modifications can only be made by removing the floor panels. According to another installation method, the floor panels are loosely installed on the subfloor, whereby the panels fit together with each other by tongue and groove engagement, thus they are mostly glued together in the tongue and groove. Flooring obtained in this way is also called floating parquet flooring, which has the advantages of easy installation and the entire floor surface being movable, which generally facilitates the acceptance of possible expansion and contraction.

[0003] The selection and requirements for flooring have also evolved. Flooring used to be made from wood or wood-derived products, but recently the market has expanded to include plastic panels, such as PVC panels, and even mineral panels, such as magnesium oxide panels. Each of these alternatives has its advantages and disadvantages. One disadvantage is that it can be difficult to bond and lock the panels together, and to lock them in a waterproof bond between the panels.

[0004] Therefore, one object of the present invention is to provide an improved inter-panel bonding, particularly a waterproof bonding. [Summary of the Invention]

[0005] The present invention thus provides a panel, particularly a floor panel, comprising: at least one first connecting member and at least one second connecting member disposed on opposite sides of the panel, wherein the first connecting member and the second connecting member of another panel are configured to engage in a downward movement; wherein the first connecting member comprises: an upward tongue, at least one upward wing located at a distance from the upward tongue, and an upward groove formed between the upward tongue and the upward wing, wherein the upward groove is adapted to receive at least a portion of the downward tongue of the second connecting member of the other panel, wherein the side of the upward tongue facing the upward wing is the inner side of the upward tongue, and the side of the upward tongue away from the upward wing is the outer side of the upward tongue; wherein the second connecting member comprises: a downward tongue, at least one downward wing located at a distance from the downward tongue, and a downward groove formed between the downward tongue and the downward wing, wherein the downward groove is adapted to receive at least a portion of the upward tongue of the first connecting member of the other panel, wherein The side of the downward tongue facing the downward wing is the inner side of the downward tongue, and the side of the downward tongue away from the downward wing is the outer side of the downward tongue; wherein the outer side of the downward tongue and the upward wing both include an upper contact surface near / located / adjacent to / facing the top of the panel, wherein, in the closed state of the panel, the upper contact surfaces are in contact with each other, wherein at least one of the contact surfaces preferably extends at least partially vertically; wherein, the outer side of the upward tongue includes: a first locking element, which is in the form of an outward protrusion, and wherein the downward wing is provided with a second locking element, which is in the form of a recess, wherein, in the closed state of the panel, at least a portion of the first locking element is in contact with at least a portion of the second locking element, forming a locking element surface; Wherein, the outwardly protruding outer side includes an upper portion and an adjacent lower portion, wherein the lower portion includes an inclined locking surface, and the upper portion includes a guide surface, the guide surface being preferably curved; wherein, the recess includes an upper portion and an adjacent lower portion, wherein the lower portion includes an inclined locking surface; wherein, in the panel's engaged state, the contact portion between the first locking element and the second locking element is the inclined locking surface of these locking elements, and / or, wherein, in the panel's engaged state, the upper portions of the first locking element and the second locking element are at least partially spaced apart.

[0006] It should be noted that in describing the present invention, terms such as top, bottom, upper, lower, horizontal, and vertical are based on the floor configuration, with the upward-facing side being the top side or upper side, and the side on the bottom floor being the bottom side or lower side, and the panel being placed horizontally or on a horizontal plane. When used as a wall covering, this is also possible for the panel according to the present invention, in which case it is usually installed vertically. The side facing the wall is the bottom, the side facing the room is the top, and vertical and horizontal are flipped. The wall panel itself can also be placed on the floor, just as if the panel were placed as a floor panel. This also applies to ceiling coverings, which is also possible for the panel according to the present invention, wherein the panel is installed on the ceiling. The top and bottom are flipped. The ceiling panel itself can also be placed on the floor, just as if the panel were placed as a floor panel.

[0007] The connecting parts of the two panels interact and provide locking between the panels, typically in the horizontal and vertical directions. The upward tongue is positioned in the downward groove, and the downward tongue is positioned in the upward groove, providing, for example, locking of a floor covering on the panel plane or in the horizontal direction.

[0008] Preferably, at least a portion, more preferably the entire inner side, of the upward tongue is inclined toward the upward flank, and more preferably, at least a portion, more preferably the entire inner side, of the downward tongue is inclined toward the downward flank. This generally produces the beneficial effect that the upward tongue is at least partially surrounded and secured by the downward groove and may be clamped, and the downward tongue is at least partially surrounded and secured by the upward groove and may be clamped.

[0009] Panels are typically configured to engage with a downward movement. This movement, also known as a pull-down or vertical movement, may mean that a new panel can be pushed into an already placed panel. This engagement can also be achieved when panels are joined by a compression or scissor movement. Alternatively, panels may be configured to engage with a tilting (downward) movement. This movement may also be referred to as a rotational movement, in which a portion of a new panel is inserted into a portion of an already placed panel and fully inserted by the tilting movement. In a preferred embodiment, the panel includes at least one third engaging member and at least one fourth engaging member disposed on another pair of opposite sides of the panel, wherein the third engaging member of the panel and the fourth engaging member of the other panel are preferably configured to engage with each other by a downward tilting movement. Preferably, the third coupling member includes: a lateral tongue extending in a direction substantially parallel to the upper side of the core; at least one second downward wing located at a distance from the lateral tongue; and a second downward groove formed between the lateral tongue and the second downward wing, wherein the fourth coupling member includes: a third groove configured to receive at least a portion of the lateral tongue of the third coupling profile of an adjacent panel, the third groove being defined by an upper lip and a lower lip, wherein the lower lip is provided with an upward locking element, wherein the third coupling member and the fourth coupling member are configured such that two of the panels can be coupled by means of rotational movement, wherein, in the coupled state, at least a portion of the lateral tongue of a first panel is inserted into the third groove of an adjacent second panel, and wherein at least a portion of the upward locking element of the second panel is inserted into the second downward groove of the first panel.

[0010] To form a tight connection at the top, these panels contact each other at the upper contact surfaces. Preferably, these upper contact surfaces are substantially planar parallel, and both contact surfaces can extend vertically to increase the contact surface. It is generally advantageous that at least one upper contact surface is slightly inclined relative to a vertical plane, wherein the at least one slightly inclined contact surface and the vertical plane preferably form an angle between 0 and 2 degrees, more preferably between 0 and 1 degree, even more preferably between 0 and 0.5 degrees, and most preferably between 0 and 0.3 degrees. Preferably, the upper contact surface of the downward tongue extends vertically, and wherein the upper contact surface of the upward wing is inclined downward in a direction away from the upward tongue, wherein, preferably, the vertical upper contact surface of the downward tongue and the inclined upper contact surface of the upward wing form an angle between 0 and 2 degrees, more preferably between 0 and 1 degree, even more preferably between 0 and 0.5 degrees, and most preferably between 0 and 0.3 degrees. It is also conceivable that the upper contact surfaces of the upward wing extend vertically, while the upper contact surfaces of the downward tongue are inclined downwards in the direction toward the downward wing. Preferably, the inclined upper contact surfaces of the downward tongue and the vertical upper contact surfaces of the upward wing form an angle between 0 and 2 degrees, more preferably between 0 and 1 degree, even more preferably between 0 and 0.5 degrees, and most preferably between 0 and 0.3 degrees. It is also conceivable that the upper contact surfaces of each downward tongue and the upper contact surfaces of the upward wing are at least partially inclined relative to a vertical plane (i.e., a plane perpendicular to the panel). This inclination preferably causes both upper contact surfaces to incline downwards away from each other. The technical effect of these embodiments is that a tighter contact between the upper contact surfaces can be achieved at the top seam formed between the panels, which is beneficial for forming a waterproof barrier. Furthermore, the aforementioned inclination generally reduces sensitivity to tolerances and precision during manufacturing and assembly. Slightly inclined upper contact surfaces can prevent squeaking between interconnected panels. This tilt also allows for a more secure or better connection of the combined panels at the top, wherein the panels are configured to be in full contact when combined.

[0011] The upper contact surface is not necessarily the upper surface of the panel. For example, the panel may have a chamfered or beveled top surface or grout, which will provide a decorative function to the surface of the panel. Preferably, the upper contact surface is the upper surface of the two panels in contact.

[0012] Furthermore, in one embodiment, the outer side of the downward tongue includes at least one, preferably trapezoidal, recess between the upper contact surface and the inclined contact surface of the downward tongue, wherein, in the coupled state of adjacent panels, the recess is preferably located at a distance from the upper contact surface of the upward wing. The recess allows (partial) expansion or swelling of the panel material, preventing damage or dislocation of the bond between the two interconnected panels. The recess also serves as an additional dust collection chamber to prevent dust from interfering with the contact of the upper contact surface. The recess may be located between the upper contact surface of the downward tongue and the inclined contact surface and / or the third locking element of the downward tongue, or at the transition between the upper contact surface, the inclined contact surface, and / or the third locking element of the downward tongue.

[0013] Preferably, the panels or their connecting components are configured to apply a locking force when joined, forcing the panels toward each other. This locking force can be achieved, for example, through a pre-tightening configuration or through a connecting component that is slightly larger than the other. In floor panels, this generates a force in the horizontal direction or on the plane of the floor panel. This locking force preferably pushes the panels toward each other in the main plane of the panels, thereby pushing the upper contact surfaces together, wherein this pre-tightening force improves the connection between the panels and preferably forms a waterproof seal on the top of the panels.

[0014] It is conceivable that, due to locking or clamping forces, during the engagement of adjacent inclined contact surfaces, the area or space where the inclined contact surface of the downward tongue is located or around it will undergo elastic or plastic deformation. The type of deformation usually depends on the material properties of the panel and the specific design of the engagement components.

[0015] The outer side of the upward tongue includes: a first locking element, which is, for example, in the form of an outward protrusion, and a second locking element, which is, for example, in the form of a recess, may be provided on the downward side wing, wherein at least a portion of the first locking element and at least a portion of the second locking element are in contact in the engaged state of the panels and form a locking element surface. The two locking elements can thus work together to provide locking, particularly in the vertical direction or perpendicular to the (main) plane of the panel. Preferably, the first and second locking elements are integrally formed with the panel and can be, for example, milled into the panel material. The application of the cooperating locking elements prevents substantial vertical displacement of the two panels relative to each other. Preferably, one or both of the first and second locking elements are substantially rigidly connected to the remainder of the panel, thereby achieving a relatively durable and secure locking, since relatively weak locking components that may experience material fatigue relatively quickly are not used. The first locking element may be formed as an integral part of the upward tongue, wherein the first locking element may be formed by deformation, for example, of the protruding (outward protrusion) or recessed (inward protrusion) edge of the upward tongue.

[0016] The first locking element may be an outwardly protruding portion, wherein the outer side of the outwardly protruding portion includes an upper portion and an adjacent lower portion, wherein the lower portion includes an inclined locking surface and the upper portion includes a guide surface, which is preferably curved. During engagement, the first locking element on the outer side of the upward tongue encounters a downward flank of another panel, which, being a protruding portion of the panel and typically the outermost portion of the panel on one side, requires overcoming forces to press one panel into the other during engagement. By providing a (curved) guide surface on the upper portion, another panel is guided downward, thereby allowing engagement to occur gradually and preventing large material deformation and / or peak stress. The lower portion may therefore be inclined, forming a portion of the protrusion that turns from the outermost portion of the protrusion toward the upward tongue. The inclined surface also provides a guiding function, guiding the panels to their final stage. The inclination of the locking surface further allows for potential upward forces or movements of the panels that create vertical and horizontal force components. The horizontal component can be used to hold the panels together, forcing the panels closer to each other to improve the connection and the waterproofing of the connection between the panels. The second locking element may be a recess comprising an upper portion and an adjacent lower portion, wherein the lower portion includes a sloped locking surface to interact with the first locking element. Sloping surfaces also have advantages, such as being relatively easier to manufacture or mill compared to circular surfaces, and relatively easier to allow for a relatively large contact surface between them to distribute locking forces in the engaging panel. Preferably, each sloped locking surface is a surface defining a plane (planar surface) that forms a crease or kink with the curved upper portion of the corresponding locking element. Preferably, the planar surfaces are positioned parallel to the plane formed by the sloped contact surfaces of the panel. For smooth guidance, the upward tongue preferably extends vertically downwards on its outer side and upwards to bulge outwards. The intersection of the outwardly bulging upper portion and the vertical outer side of the upward tongue includes a crease or kink. The outward bulge is preferably formed by a curved upper portion whose curvature gradually flattens below the substantially vertically oriented lower portion. The upper portion extends downwards to the lower portion, which is composed of planar inclined locking surfaces. The inclined locking surfaces form creases or kinks with the flat lower region of the outwardly convex upper portion. The recess in the downward flank preferably complements the outward convexity (shape fit), thus preferably, the upward flank includes a vertical outer portion that extends from the upper surface of the downward groove upwards to the recess. The inward recess includes a curved upper portion, the curvature of which gradually flattens below the substantially vertically oriented upper portion. The inclined locking surfaces form creases or kinks with the flat lower region of the upper portion of the recess. These inclined locking surfaces have substantially the same angle of inclination relative to the vertical plane.

[0017] Preferably, in the coupled state of adjacent panels, the upper part of the first locking element and the upper part of the second locking element are completely spaced apart. This typically results in the situation where, in the coupled state of adjacent panels, the outward protrusion and the recess engage only through the inclined locking surfaces. In this way, the functionality and effectiveness of the inclined locking surfaces can be ensured in an improved manner. Preferably, in the coupled state of adjacent panels, only a portion of the inclined locking surface of the lower part of the outward protrusion interacts with only a portion of the inclined locking surface of the lower part of the recess. Preferably, the length of the inclined locking surface of the lower part of the outward protrusion is greater than the length of the inclined locking surface of the lower part of the recess, preferably at least 1.5 times greater.

[0018] Preferably, the upper outer portion is substantially vertical and defines an outer vertical plane, wherein at least a portion of the first locking element protrudes at least partially from the outer vertical plane, preferably by a maximum of 2 mm in the horizontal direction, more preferably by a maximum of 1 mm. The outer vertical plane generally divides the upward tongue into: an inner section facing the upward wing; and an outer section including the first locking element, wherein the maximum width of the inner section is preferably at least 8 times that of the outer section, more preferably at least 10 times.

[0019] Preferably, the first and second locking elements are located at a height below the height of the inclined contact surface (if applied) and / or the height of the third and fourth locking elements (if applied) of the lower tongue and upper wing. This generally reduces the degree of deformation of the coupling assembly during coupling, which is beneficial to the lifespan and reliability of the coupling assembly. Preferably, the height of the inclined contact surface of the lower tongue and upper wing is above the height of the highest point of the upper tongue. This generally helps to form a waterproof barrier as close as possible to the top surface of the panel.

[0020] Preferably, at least a portion of the upper part of the outwardly protruding portion located on the outer side of the upward tongue is at a height higher than the height defined by the lowest point of the upward groove, and preferably, at least a portion of the upper part of the recess is at a height higher than the height defined by the lowest point of the upward groove. The inclined contact surfaces of the protrusion and the recess are preferably located below the lowest point of the upward groove. This generally facilitates the joining process, but may also facilitate the separation of the joined panels by means of downward directional tilting movement of the panels relative to each other.

[0021] Compared to the lower portion, the upper portion can extend over a larger vertical cross-section to gradually guide the panel into place. The upper portion typically does not provide a vertical locking effect (because the outwardly protruding and recessed upper portion is better spaced apart during engagement), making its horizontal portion less correlated compared to the lower portion, which typically does provide a vertical locking effect. In the engaged state of the panel, the contact portion between the first and second locking elements is typically formed by the inclined locking surfaces of the locking elements, and thus formed by the lower portion. In the engaged state of the panel, the upper portions of the first and second locking elements can be at least partially spaced apart. This spacing allows the upward tongue to move upward without obstruction by the downward flanks; this upward movement can then be transferred and converted into a closing horizontal movement to improve the connection or locking of the panel, thereby forcing the panel to close.

[0022] The outer side of the upward tongue may include an upper outer portion and a lower outer portion, wherein the first locking element is disposed between the upper outer portion and the lower outer portion, wherein the lower outer portion is disposed closer to the inner side of the upward tongue than the upper outer portion. Preferably, the upper outer portion may be substantially vertical and define an outer vertical plane, wherein the first locking element protrudes at least partially from the outer vertical plane, preferably by a maximum of 2 mm. For example, the upper outer portion above the first locking element defines a vertical plane, and the lower outer portion below the first locking element defines a parallel but offset vertical plane, and the vertical plane of the lower outer portion is located closer to the upward flank. This difference creates a relatively large distance between the panels at the intersection between the lower outer portion and the inclined locking surface of the upward tongue, which allows for greater upward tilting or rotational movement of the upward tongue, thereby allowing for potentially larger closing forces or tensions applied by the locking elements to improve panel connection and waterproofing.

[0023] The lower outer portion can be substantially vertical, and the inclined locking surface or lower part forms an angle between 100 and 175 degrees, particularly between 100 and 150 degrees, and more particularly between 110 and 135 degrees, with the lower outer portion. Such an angle has proven to provide an optimal combination of locking and guiding performance. The angle formed by the upper contact surface and the inclined contact surface, and the angle formed by the lower outer portion and the inclined locking surface or lower part, can differ by no more than 20 degrees, and are preferably the same angle. This allows for relatively easy manufacturing, where the same or similar tools can be used to mill the two components in the panel.

[0024] The outermost portion of the first locking element may be positioned at a horizontal height lower than the upward groove. In this way, during the downward movement of the panel during engagement, the widest or outermost portion of the first locking element will be encountered relatively late, which is beneficial for the engagement of the two panels.

[0025] The outer side of the downward tongue includes a third locking element, which is located below and preferably adjacent to the upper contact surface of the downward tongue, and the upper wing includes a fourth locking element, which is located below and preferably adjacent to the upper contact surface of the upper wing. In the coupled state of adjacent panels, at least a portion of the third locking element of the panel is in contact with at least a portion of the second locking element of the other panel to achieve a locking effect between the panels, preferably a vertical locking effect. Preferably, in the coupled state of adjacent panels, the upper contact surface defines an inner vertical plane, wherein the third and fourth locking elements are located on the same, and more preferably on one side, of the inner vertical plane away from the upward tongue. Preferably, the third and fourth locking elements extend at most 1 mm, more preferably at most 0.5 mm, and more preferably at most 0.2 mm in the horizontal direction relative to the inner vertical plane. Each of the third and fourth locking elements may include a protrusion and / or a groove, wherein, preferably, the third locking element includes a protrusion, and wherein the fourth locking element includes a groove.

[0026] Preferably, the heights of the third and fourth locking elements are higher than the height of the highest point of the upward tongue, which reduces material deformation and thus reduces material stress during engagement and disengagement. Preferably, the first and second locking elements are located at a height lower than the heights of the third and fourth locking elements, which also reduces material deformation and thus reduces material stress during engagement and disengagement.

[0027] Preferably, the outer side of the downward tongue includes at least one recess between the upper contact surface and the third locking element of the downward tongue, wherein, in the engaged state of adjacent panels, the recess is preferably located at a distance from the upper contact surface of the upward wing. The recess allows (partial) expansion or swelling of the panel material, preventing damage or dislocation of the bond between the two interconnected panels. The recess also serves as an additional dust collection chamber to prevent dust from interfering with the contact of the upper contact surface. The groove may be provided between the upper contact surface of the downward tongue and the third locking element of the downward tongue, or at the transition between the upper contact surface and the third locking element.

[0028] An inclined contact surface may exist adjacent to, and typically directly adjacent to, the upper contact surface or directly below the upper contact surface. These panels contact at this inclined surface to form a connection or seal between the panels. The inclination is preferably such that, when viewing the downward tongue, the inclined surface extends outward, while when viewing the upward flank, the inclined surface extends inward. The inclination angle causes the downward tongue to have a protruding portion and the upward flank to have a recessed portion, both of which are in contact in the engaged state, thereby providing a vertical locking effect. The inclination also creates a slight tortuous seal, thereby improving the waterproof performance of the connection.

[0029] Preferably, the inclined contact surface of the downward tongue extends at most 1 mm in the horizontal direction relative to the inner vertical surface, more preferably at most 0.5 mm, and even more preferably at most 0.2 mm, the inner vertical surface being defined by the upper contact surface (contact portion) of the panel in the joined state. Preferably, the height of the inclined contact surface of the downward tongue and the upward wing is higher than the height of the highest point of the upward tongue. This reduces material stress during the joining process, which will benefit the reliability of the durability of the adjacent panel joint. Typically, the inclined contact surface of the downward tongue defines at least a portion of the third locking element, and the inclined contact surface of the upward wing defines at least a portion of the fourth locking element.

[0030] The downward tongue may include an outer surface that is adjacent to, and typically directly adjacent to, or directly below the inclined contact surface. This outer surface may be, for example, the outermost surface of the downward tongue, or the surface of the outer tongue furthest from the downward flank. Similarly, the upward flank includes an inner surface that is adjacent to, and typically directly adjacent to, or directly below the inclined contact surface. A space exists between the inner and outer surfaces. This space is intended to prevent any force applied to or exerted by the panel from causing the panels to push together anywhere except at the upper contact surface and / or the inclined contact surface. If the inner and outer surfaces are in contact, they would prevent the upper contact surface from contacting, which would compromise the waterproof properties of the connection. At the top, at the upper contact surface and the inclined contact surface, the purpose is to thereby create a connection between the panels, while below these contact surfaces, the purpose is to prevent such a connection.

[0031] The upper contact surface may be at least partially perpendicular to and define an inner vertical plane, wherein the inclined contact surface of the downward tongue extends beyond the inner vertical plane, preferably by a maximum of 1 mm in the horizontal direction, and wherein the inclined contact surface of the upward flank is inward compared to the inner vertical plane. This configuration causes the downward tongue to partially protrude from the inner vertical plane and the upward flank to partially recess, wherein in the engaged state, the inclined contact surfaces can grip each other behind each other to create a vertical locking effect. By limiting the horizontal extent of the protrusion, the downward tongue can still engage with downward or vertical movement while providing a vertical locking effect. A portion of the downward tongue may thereby extend beyond the inner vertical plane, and this portion can be elongated as a vertical portion that is larger than the horizontal portion, wherein preferably the vertical portion is at least 3 times the length of the horizontal portion. This allows for a relatively small horizontal portion, so that the panel can still be connected using vertical or downward movement.

[0032] A portion of the downward tongue may extend beyond the inner vertical plane, wherein said portion may be substantially trapezoidal or wedge-shaped. This shape allows the portion to wedge into the space provided in the upward flank when subjected to any locking, engagement, or other forces in the panel plane, while also providing a sturdy portion capable of withstanding forces to form a tight connection between the panels. This correspondingly improves the waterproof properties of the connection between the panels.

[0033] The inclined contact surface can be simultaneously disposed outside and / or adjacent to the inner vertical plane, and preferably entirely disposed outside the inner vertical plane or entirely on one side of the inner vertical plane. This allows for a relatively simple construction that provides a tight connection between the two panels. Preferably, the upper contact surface defining the vertical plane transitions directly to the inclined contact surface. In this configuration, the connection of the contact surfaces continues from the upper contact surface to the inclined contact surface, increasing the uninterrupted surface and thereby improving the connection between the panels and the waterproof properties of the connection. In the joined state, the bottom of the downward tongue can contact the upper side of the upward groove at the groove contact surface, and wherein a gap exists between the first and second joining members, extending from the inclined contact surface to the groove contact surface. This gap can be used to collect, for example, dust or debris from the panels that may be generated during the joining of the two panels. In addition, this gap is designed to prevent any force applied to or exerted by the panels from causing the panels to be pushed together anywhere except at the upper contact surface and / or the inclined contact surface. The groove contact surface is preferably primarily horizontal, allowing forces applied to the panel, particularly those applied to the connection between two panels, typically transmitted in a downward direction through stepping on the panel to the underlying floor or surface. Preferably, the upward groove and downward tongue are shaped such that the gap between the groove contact surface and the outward surface of the bottom of the downward tongue spans a gap width extending more than a quarter of the groove width, more preferably at least a third, and even more preferably more than half the groove width. The groove width is defined by the minimum horizontal width between the outer surface of the upward tongue and the upward flank.

[0034] In the joined state, the upper surface of the upward tongue and the upper surface of the downward groove can be spaced apart from each other, such that a gap exists between the two surfaces. Again, this gap is intended to prevent any force applied to or exerted by the panels from pushing the panels together anywhere except at the upper contact surface and / or the inclined contact surface. The upward movement of the upward tongue can, for example, create a horizontal force that closes or secures the connection between the two panels, more particularly in a so-called closed groove locking connection. To allow this upward movement, a gap is provided between the upward tongue and the downward groove. The upper surface of the downward groove can, for example, be formed by the bottom surface of the bridge portion that connects the downward tongue to the rest of the panel.

[0035] The upper contact surface and the inclined contact surface of the upward-facing wing can form a first angle with each other, and the upper contact surface and the inclined contact surface of the downward-facing tongue can form a second angle with each other, wherein the difference between the first angle and the second angle is within 20 degrees. For example, the inclined contact surfaces of the upward-facing wing can form a first angle of 120 degrees with each other, and the upper contact surface and the inclined contact surface of the downward-facing tongue can form a second angle of 125 degrees with each other. The difference between the two angles is 5 degrees, which is less than 20 degrees, and therefore within 20 degrees. By generating the difference between the angles, a configuration can be provided in which a wedging action can be achieved to increase the locking force and waterproof properties in the connection. Pushing or wedging the locking elements into each other can cause an increase in the locking force or connection in the panel.

[0036] Preferably, in the coupled state of adjacent panels, a space exists between at least a portion of the outer surface of the panel and at least a portion of the inner surface of the adjacent panel. Preferably, the outer side of the upward tongue includes an upper outer portion that defines an outer vertical plane that divides the upward tongue into: an inner segment pointing upward wing; and an outer segment including a first locking element, wherein the maximum width of the inner portion is at least 8 times, preferably at least 10 times, the maximum width of the outer portion. This results in a limited effective width of the first locking element, which is beneficial to the coupling process and reduces the degree of material deformation during coupling, which is beneficial to the reliability and durability of the interconnect panel coupling.

[0037] Panels according to the invention are, for example, made at least partially of magnesium oxide, or based on magnesium oxide. A panel according to the invention may comprise: a core having upper and lower sides, and a decorative top structure (or top section) directly or indirectly fixed to the upper side of the core, wherein the core comprises: at least one composite layer comprising: at least one composition based on magnesium oxide (magnesia) and / or magnesium hydroxide, particularly magnesium oxychloride cement. Particles, particularly cellulose and / or polysiloxane particles, may be dispersed in the magnesium oxychloride cement. Optionally, one or more reinforcing layers, such as glass fiber layers, may be embedded in the composite layer. The core composition may also comprise magnesium oxychloride that forms magnesium oxychloride (MOC) cement and / or magnesium oxysulfate that forms magnesium oxysulfate (MOS) cement.

[0038] It has been found that the application of compositions based on magnesium oxide and / or magnesium hydroxide, particularly magnesium oxycement, including MOS and MOC, significantly improves the flammability (non-flammability) of the decorative panels themselves. Furthermore, the dimensional stability of the relatively fire-resistant panels is also significantly improved when subjected to temperature fluctuations during normal use. Magnesium oxycement is cement based on magnesium oxide (magnesium oxide), where cement is a reaction product of a chemical reaction in which magnesium oxide is already one of the reactants. In magnesium oxycement, magnesium oxide can still be present and / or has undergone a chemical reaction, forming another type of chemical bond, which will be explained in more detail below. Additional advantages of magnesium oxycement compared to other cement types are also presented below. The first additional advantage is that magnesium oxycement can be manufactured in a relatively energy-efficient and therefore cost-efficient manner. Furthermore, magnesium oxycement has relatively high compressive and tensile strengths. An additional advantage of magnesium oxycement is its natural affinity for (typically inexpensive) cellulose materials, such as plant fiber wood flour (wood ash) and / or sawdust; this not only improves the bonding strength of the magnesium oxycement but also results in weight savings and better sound insulation (reduction). Magnesium oxide, when combined with cellulose and optionally clay, produces magnesium oxycement that breathes water vapor; this cement does not deteriorate (rot) because it effectively expels moisture. Furthermore, magnesium oxycement is a relatively good insulating material, providing both thermal and electrical insulation, making the panels particularly suitable for floors in radar stations and hospital operating rooms. An additional advantage of magnesium oxycement is its relatively low pH value compared to other cement types, which allows for greater durability of the dispersed particles in the cement matrix and / or (as glass fiber) as the reinforcing layer, and, moreover, the ability to use other types of fibers in a durable manner. Furthermore, an additional advantage of decorative panels is their suitability for both indoor and outdoor use.

[0039] As already mentioned, magnesium oxychloride cement is based on magnesium oxide and / or magnesium hydroxide. Magnesium oxychloride cement itself may not contain magnesium oxide, but rather depends on further reactants used in its production. Here, for example, it is conceivable that magnesium oxide, as a reactant, is converted to magnesium hydroxide during the production of magnesium oxychloride cement. Therefore, magnesium oxychloride cement itself may contain magnesium hydroxide. Typically, magnesium oxychloride cement contains water, particularly hydrated water. Water is typically used as a binder to produce a strong and adhesive cementitious matrix.

[0040] Magnesium oxychloride-based compositions, particularly magnesium oxychloride cement, may contain magnesium chloride (MgCl2). Typically, magnesium oxychloride cement containing magnesium oxychloride (MOC) is formed when magnesium oxide (MgO) is mixed with magnesium chloride in an aqueous solution. The bonding phases are Mg(OH)2, 5Mg(OH)2.MgCl2.8H2O (type 5), 3Mg(OH)2.MgCl2.8H2O (type 3), and Mg2(OH)ClCO3•3H2O. Type 5 is the preferred phase because it possesses excellent mechanical properties. Compared to other cement types (such as Portland cement), MOC exhibits superior properties. MOC does not require wet curing, has high refractoriness, low thermal conductivity, and good abrasion resistance. MOC cement can be used with various binders (additives) and fibers, exhibiting good anti-adhesion properties. It also accepts various types of surface treatments. MOC develops high compressive strength (e.g., 8,000-10,000 psi) within 48 hours. The compressive strength increases in the early stages of the curing process – the strength after 48 hours will be at least 80% of the final strength. The compressive strength of MOC is preferably between 40 and 100 N / mm². The flexural tensile strength is preferably 10-17 N / mm². The surface hardness of MOC is preferably 50-250 N / mm². The E-modulus is preferably 1-3 10⁴ N / mm². MOC has relatively low flexural strength, but this can be significantly improved by adding fibers, particularly cellulose-based fibers. MOC is compatible with a wide range of plastic fibers, mineral fibers (such as basalt fibers), and organic fibers such as bagasse, wood fibers, and hemp fibers. The MOC used in the panels according to the invention can be enriched with one or more of these fiber types. MOC exhibits non-shrinkage, abrasion resistance, and acceptable water resistance, impact resistance, dent resistance, and scratch resistance. MOC is resistant to heat and freeze-thaw cycles and does not require air entrainment to improve durability. Furthermore, MOC possesses excellent thermal conductivity, low electrical conductivity, and excellent adhesion to various substrates and additives, along with acceptable fire resistance. However, MOC performs poorly when panels are exposed to relatively extreme weather conditions (temperature and humidity), which can affect curing properties and the development of the magnesium oxychloride phase. Over time, atmospheric carbon dioxide reacts with magnesium oxychloride to form a surface layer of Mg2(OH)ClCO3·3H2O. This layer slows the leaching process. Ultimately, additional leaching leads to the formation of hydromagnesite, 4MgO·3CO3·4H2O, which is insoluble and allows the cement to maintain its structural integrity.

[0041] Magnesium-based compositions, particularly magnesium oxychloride cement, can be based on magnesium sulfate, especially the heptahydrate sulfate mineral Epsom salt (MgSO4·7H2O). This latter salt is also known as Epsom salt. In aqueous solution, MgO reacts with MgSO4, resulting in magnesium oxysulfate (MOS) cement, which has very good binding properties. In MOS, 5Mg(OH)2·MgSO4·8H2O is the most common chemical phase. Although MOS is not as strong as MOC, it is more suitable for fire-retardant applications because MOS begins to decompose at temperatures more than twice as high as MOC, providing longer-lasting fire protection. Furthermore, the products of their decomposition at elevated temperatures (sulfur dioxide) are less toxic than the products of oxychloride decomposition at elevated temperatures (hydrochloric acid), and are also less corrosive. In addition, weather 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 crystalline phases in the cement. It has been found that at different temperatures between 30 and 120 degrees Celsius, four basic magnesium salts can promote the mechanical strength of MOS cement present in the ternary system MgO-MgSO4-H2O: 5Mg(OH)2·MgSO4·3H2O (513 phase), 3Mg(OH)2·MgSO4·8H2O (318 phase), Mg(OH)2·2MgSO4·3H2O (123 phase), and Mg(OH)2·MgSO4·5H2O (115 phase). Typically, when the molar ratio of MgO to MgSO4 is fixed at (approximately) 5:1, the 513 and 318 phases can only be obtained by curing cement under saturated steam conditions. The 318 phase has been found to significantly contribute to the mechanical strength and is stable at room temperature, and is therefore preferred in the applied MOS. This also applies to the 513 phase. The 513 phase typically has a (micro)structure containing needle-like structures. This can be verified by SEM analysis. Magnesium oxysulfate (5Mg(OH)₂·MgSO₄·3H₂O) needles can be formed substantially uniformly and are typically 10-15 µm in length and 0.4-1.0 µm in diameter. When referring to needle-like structures, it can also refer to lamellar and / or whisker structures. In practice, obtaining a MOS containing more than 50% of the 513 or 318 phase seems impractical, but the mechanical strength of the MOS can be improved by adjusting the crystal phase composition. Preferably, the magnesium oxycement contains at least 10%, preferably at least 20%, and more preferably at least 30% of 5Mg(OH)₂•MgSO₄•3H₂O (513 phase). This preferred embodiment will provide a magnesium oxycement with sufficient mechanical strength for use as a core layer in floor panels.

[0042] The crystal phase of MOS can be adjusted by modifying it with organic acids, preferably citric acid and / or phosphoric acid and / or phosphates. During this modification process, new MOS phases can be obtained, which can be represented by 5Mg(OH)₂·MgSO₄·5H₂O (phase 515) and Mg(OH)₂•MgSO₄•7H₂O (phase 517). Phase 515 can be obtained by modifying MOS with citric acid. Phase 517 can be obtained by modifying MOS with phosphoric acid and / or phosphates (H₃PO₄, KH₂PO₄, K₃PO₄, and K₂HPO₄). These 515 and 517 phases can be identified by elemental chemical analysis, with SEM analysis demonstrating that the microstructure of both phases is needle-like crystals, insoluble in water. In particular, the addition of citric acid can improve the pressure resistance and water resistance of MOS. Therefore, preferably, when applied to a panel according to the invention, the MOS comprises 5Mg(OH)₂·MgSO₄·5H₂O (515 phase) and / or Mg(OH)₂•MgSO₄•7H₂O (517 phase). As mentioned above, the addition of phosphoric acid and phosphates can prolong the setting time and improve the compressive strength and water resistance of the MOS cement by altering the hydration process and phase composition of MgO. Here, phosphoric acid or phosphates ionize in solution to form H₂PO₄⁻, HPO₄²⁻, and / or PO₄³⁻, wherein these anions adsorb onto [Mg(OH)(H₂O)x]⁺ to inhibit the formation of Mg(OH)₂ and further promote the formation of a new magnesium sulfite phase, resulting in a dense MOS cement structure with high mechanical strength and good water resistance. The improvements resulting from adding phosphoric acid or phosphates to the MOS cement follow the order H₃PO₄ = KH₂PO₄⁺ >> K₂HPO₄ >> K₃PO₄. Compared to MOC, MOS exhibits better volumetric stability, less shrinkage, better adhesion properties, and lower corrosivity over a significantly wider range of weather conditions, thus making it superior to MOC. The density of MOS typically varies between 350 and 650 kg / m³. The preferred flexural tensile strength is 1–7 N / mm².

[0043] The magnesium cement composition preferably contains one or more polysiloxane-based additives. Various polysiloxane-based additives can be used, including but not limited to polysiloxane oils, neutral-curing polysiloxanes, silicones, silicone fluids, polysiloxane (micro)spheres or polysiloxane particles, and mixtures and derivatives thereof. Polysiloxane oils include liquid polymeric siloxanes having organic side chains, including but not limited to poly(methyl)siloxanes and their derivatives. Neutral-curing polysiloxanes include those that release ethanol or other volatile organic compounds (VOCs) when cured. Other polysiloxane-based additives and / or siloxanes (e.g., siloxane polymers) may also be used, including but not limited to hydroxyl (or hydroxyl-terminated) siloxanes and / or siloxanes terminated with other reactive groups, acrylate siloxanes, urethane siloxanes, epoxy siloxanes, and mixtures and derivatives thereof. As detailed below, one or more crosslinking agents (e.g., polysiloxane-based crosslinking agents) may also be used. The viscosity of one or more polysiloxane-based additives (e.g., polysiloxane oils, neutral-curing polysiloxanes, silicone fluids, siloxane polymers, etc.) may be approximately 100 cSt (at 25°C), which is referred to as low viscosity. In alternative embodiments, one or more polysiloxane-based additives (e.g., polysiloxane oils, neutral-curing polysiloxanes, silicone fluids, silicone polymers, etc.) have a viscosity between about 20 cSt (25°C) and about 2000 cSt (25°C). In other embodiments, one or more polysiloxane-based additives (e.g., polysiloxane oils, neutral-curing polysiloxanes, silicone fluids, silicone polymers, etc.) have a viscosity between about 100 cSt (25°C) and about 1250 cSt (25°C). In other embodiments, one or more polysiloxane-based additives (e.g., polysiloxane oils, neutral-curing polysiloxanes, silicone fluids, silicone polymers, etc.) have a viscosity between about 250 cSt (25°C) and 1000 cSt (25°C). In yet another embodiment, one or more polysiloxane-based additives (e.g., polysiloxane oils, neutral-curing polysiloxanes, silicone fluids, silicone polymers, etc.) have a viscosity between approximately 400 cSt (25°C) and 800 cSt (25°C). And in certain embodiments, one or more polysiloxane-based additives (e.g., polysiloxane oils, neutral-curing polysiloxanes, silicone fluids, silicone polymers, etc.) have a viscosity between approximately 800 cSt (25°C) and approximately 1250 cSt (25°C). One or more polysiloxane-based additives with higher and / or lower viscosities may also be used.For example, in a further embodiment, one or more polysiloxane-based additives (e.g., polysiloxane oil, neutral-curing polysiloxane, silicone fluid, siloxane polymer, etc.) have a viscosity between about 20 cSt (25°C) and about 200,000 cSt (25°C), between about 1,000 cSt (25°C) and about 100,000 cSt (25°C), or between about 80,000 cSt (25°C) and about 150,000 cSt (25°C). In other embodiments, one or more polysiloxane-based additives (e.g., polysiloxane oil, neutral-curing polysiloxane, silicone fluid, siloxane polymer, etc.) have a viscosity between about 1,000 cSt (25°C) and about 20,000 cSt (25°C), between about 1,000 cSt (25°C) and about 10,000 cSt (25°C), between about 1,000 cSt (25°C) and about 2,000 cSt (25°C), or between about 10,000 cSt (25°C) and about 20,000 cSt (25°C). In yet another embodiment, one or more polysiloxane-based additives (e.g., polysiloxane oils, neutral-curing polysiloxanes, silicone fluids, silicone polymers, etc.) have a viscosity between about 1,000 cSt (25°C) and about 80,000 cSt (25°C), between about 50,000 cSt (25°C) and about 100,000 cSt (25°C), or between about 80,000 cSt (25°C) and about 200,000 cSt (25°C). And in a further embodiment, one or more polysiloxane-based additives (e.g., polysiloxane oils, neutral-curing polysiloxanes, silicone fluids, silicone polymers, etc.) have a viscosity between about 20 cSt (25°C) and about 100 cSt (25°C). Other desired viscosities may also be used.

[0044] In a preferred embodiment, the magnesium cement composition, particularly the magnesium oxychloride cement composition, comprises a single type of polysiloxane-based additive. In other embodiments, a mixture of two or more types of polysiloxane-based additives is used. For example, in some embodiments, the magnesium oxychloride cement composition may include a mixture of one or more polysiloxane oils and neutral-curing polysiloxanes. In a particular embodiment, the weight ratio of polysiloxane oil to neutral-curing polysiloxane may be between about 1:5 and about 5:1. In other such embodiments, the weight ratio of polysiloxane oil to neutral-curing polysiloxane may be between about 1:4 and about 4:1. In other such embodiments, the weight ratio of polysiloxane oil to neutral-curing polysiloxane may be between about 1:3 and about 3:1. In yet another such embodiment, the weight ratio of polysiloxane oil to neutral-curing polysiloxane may be between about 1:2 and about 2:1. In a further embodiment like this, the weight ratio of polysiloxane oil to neutral-cured polysiloxane can be approximately 1:1.

[0045] It is conceivable that one or more crosslinking agents are used in magnesium oxychloride cement. In some embodiments, the crosslinking agent is a polysiloxane-based crosslinking agent. Exemplary crosslinking agents include, but are not limited to, methyltrimethoxysilane, methyltriethoxysilane, methyltris(methylethyl ketoxime)silane, and mixtures and derivatives thereof. Other crosslinking agents (including other polysiloxane-based crosslinking agents) may also be used. In some embodiments, the magnesium oxychloride cement composition comprises one or more polysiloxane-based additives (e.g., one or more silanols and / or silanol fluids) and one or more crosslinking agents. The weight ratio of one or more polysiloxane-based additives (such as silanols and / or silanol fluids) to the crosslinking agent may be between about 1:20 and about 20:1, between about 1:10 and about 10:1, or between about 1:1 and about 10:1.

[0046] Compared to conventional magnesium (oxychloride) cement compositions, magnesium (oxychloride) cement compositions containing one or more polysiloxane-based additives can exhibit reduced water sensitivity. Furthermore, in some embodiments, magnesium (oxychloride) cement compositions containing one or more polysiloxane-based additives can exhibit very low or no water sensitivity. Magnesium (oxychloride) cement compositions containing one or more polysiloxane-based additives can further exhibit hydrophobic and water-repellent properties.

[0047] Furthermore, magnesium (oxychloride) cement compositions containing one or more polysiloxane-based additives can exhibit improved curing properties. For example, magnesium (oxychloride) cement compositions cure to form various reaction products, including 3Mg(OH)₂.MgCl₂.8H₂O (third phase) and 5Mg(OH)₂.MgCl₂.8H₂O (fifth phase) crystal structures. In some states, a higher percentage of 5Mg(OH)₂.MgCl₂.8H₂O (fifth phase) crystal structure is preferred. In this state, adding one or more polysiloxane-based additives to the magnesium oxychloride cement composition can stabilize the curing process, which can increase the percentage yield of the 5Mg(OH)₂.MgCl₂.8H₂O (fifth phase) crystal structure. For example, in some embodiments, magnesium oxychloride compositions containing one or more polysiloxane-based additives can cure to form a 5Mg(OH)₂.MgCl₂.8H₂O (fifth phase) crystal structure of greater than 80%. In other embodiments, the magnesium oxychloride composition containing one or more polysiloxane-based additives can be cured to form a 5Mg(OH)₂·MgCl₂·8H₂O (5th phase) crystal structure with a content greater than 85%. In yet another embodiment, the magnesium oxychloride composition containing one or more polysiloxane-based additives can be cured to form a 5Mg(OH)₂·MgCl₂·8H₂O (5th phase) crystal structure with a content greater than 90%. In yet another embodiment, the magnesium oxychloride composition containing one or more polysiloxane-based additives can be cured to form a 5Mg(OH)₂·MgCl₂·8H₂O (5th phase) crystal structure with a content greater than 95%. In yet another embodiment, the magnesium oxychloride composition containing one or more polysiloxane-based additives can be cured to form a 5Mg(OH)₂·MgCl₂·8H₂O (5th phase) crystal structure with a content greater than 98%. In yet another embodiment, a magnesium oxychloride composition containing one or more polysiloxane-based additives can be cured to form approximately 100% 5Mg(OH)2.MgCl2.8H2O (the fifth phase) crystal structure.

[0048] Furthermore, magnesium (oxychloride) cement compositions containing one or more polysiloxane-based additives can also exhibit increased strength and bonding properties. If desired, magnesium (oxychloride) cement compositions containing one or more polysiloxane-based additives can also be used to manufacture relatively thin magnesium (oxychloride) cement or concrete structures. For example, magnesium (oxychloride) cement compositions containing one or more polysiloxane-based additives can be used to manufacture cement or concrete structures or layers with a thickness of less than 8 mm, preferably less than 6 mm.

[0049] To achieve bonding between the bonding components, temporary deformation of the bonding components may be required and / or even necessary. As a result, it is beneficial to mix magnesium oxide and / or magnesium hydroxide and / or magnesium chloride and / or magnesium sulfate with one or more polysiloxane-based additives, as this results in an increased degree of flexibility and / or elasticity. For example, in some embodiments, cement and concrete structures formed using magnesium oxychloride cement compositions can bend or flex without cracking or breaking.

[0050] Magnesium (oxychloride) cement compositions containing one or more polysiloxane-based additives may further contain one or more additional additives. Additional additives may be used to enhance specific properties of the composition. For example, in some embodiments, additional additives may be used to make the structure formed using the disclosed magnesium oxychloride cement composition resemble stone (e.g., granite, marble, sandstone, etc.). In certain embodiments, 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 fibers. Magnesium oxychloride cement compositions may also form UV-stable structures such that the color and / or appearance do not suffer substantial fading due to UV exposure over time. Other additives may also be included in the composition, including but not limited to plasticizers (e.g., polycarboxylate plasticizers, polycarboxylate ether-based plasticizers, etc.), surfactants, water, and mixtures and combinations thereof. As noted above, magnesium oxychloride cement compositions, if applied, may contain magnesium oxide (MgO), an aqueous solution of magnesium chloride (MgCl2(aq)), and one or more polysiloxane-based additives. Magnesium chloride (MgCl2) powder can also be used instead of magnesium chloride (MgCl2) aqueous solution. For example, magnesium chloride (MgCl2) powder can be used in combination with a certain amount of water, which will be equivalent to or otherwise similar to an aqueous solution of magnesium chloride (MgCl2(aq)).

[0051] In certain embodiments, if applied, the ratio of magnesium oxide (MgO) to an aqueous solution of magnesium chloride (MgCl2(aq)) in the magnesium oxychloride cement composition can vary. In some such embodiments, the weight ratio of magnesium oxide (MgO) to an aqueous solution of magnesium chloride (MgCl2(aq)) is between about 0.3:1 and about 1.2:1. In other embodiments, the weight ratio of magnesium oxide (MgO) to an aqueous solution of magnesium chloride (MgCl2(aq)) is between about 0.4:1 and about 1.2:1. And in yet another embodiment, the weight ratio of magnesium oxide (MgO) to an aqueous solution of magnesium chloride (MgCl2(aq)) is between about 0.5:1 and about 1.2:1.

[0052] An aqueous solution of magnesium chloride (MgCl2(aq)) can be described as (or otherwise derived from) an aqueous solution of magnesium chloride salts. An aqueous solution of magnesium chloride (MgCl2(aq)) (or magnesium chloride brine) may also include relatively small amounts of other compounds or substances, including but not limited to magnesium sulfate, magnesium phosphate, hydrochloric acid, phosphoric acid, etc.

[0053] In a preferred embodiment, the amount of one or more (liquid) polysiloxane-based additives in the magnesium oxychloride cement composition can be defined as the ratio of the polysiloxane-based additives to magnesium oxide (MgO). For example, in some embodiments, the weight ratio of the polysiloxane-based additives to magnesium oxide (MgO) is between 0.06 and 0.6.

[0054] Preferably, it is also conceivable, and even advantageous, to add at least one oil, such as linseed oil or polysiloxane oil, to the core layer. This makes the magnesium-based core layer and / or the thermoplastic-based core layer more flexible and reduces the risk of breakage. Instead of oil or in addition to oil, it is also conceivable to add one or more water-soluble polymers or polycondensation (synthetic) resins, such as polycarboxylic acids, to the core layer. The resulting advantage is that the panel does not shrink during the drying / curing / condensation process, which prevents crack formation; furthermore, after drying / curing / condensation, it provides the core layer with more hydrophobic properties, which prevent water (moisture) penetration during subsequent storage and use.

[0055] It is conceivable that the core layer comprises polycaprolactone (PCL). This biodegradable polymer is particularly preferred because it has been found to melt through an exothermic reaction of the reaction mixture. Its melting point is approximately 60°C. PCL can be low-density or high-density. The latter is particularly preferred because it produces a stronger core layer. Other polymers can be used instead or added, preferably selected from other poly(lactic acid-co-glycolic acid) (PLGA), poly(lactic acid) (PLA), poly(glycolic acid) (PGA), polyhydroxyalkanoate (PHA), polyethylene glycol (PEG), polypropylene glycol (PPG), polyesteramide (PEA), poly(lactic acid-co-caprolactone), poly(lactide-co-propyl carbonate) family, poly(sebacic acid-co-ricinoleic acid) and combinations thereof.

[0056] Alternatively, the panel, particularly the core layer, may be at least partially made of PVC, PET, PP, PS, or (thermoplastic) polyurethane (PUR). PS may be in the form of foamed PS (EPS) to further reduce the panel density, resulting in cost savings and facilitating panel handling. Preferably, at least a portion of the polymer used may be formed from recycled thermoplastic materials, such as recycled PVC or recycled PUR. Recycled PUR may be made from recyclable polymers, such as recycled PET. PET can be chemically recycled by converting it into monomers or oligomers using glycolysis or depolymerization, and subsequently into polyurethane polyols. It is also conceivable that rubber and / or elastomer portions (particles) are dispersed within at least one composite layer to improve flexibility and / or impact resistance to at least some extent. It is conceivable to use a mixture of virgin and recycled thermoplastic materials to constitute at least a portion of the core. Preferably, in this mixture, the virgin and recycled thermoplastic materials are substantially identical. For example, such a mixture may be entirely based on PVC or entirely based on PUR. When the core consists of multiple parts / layers, the core can be solid or foamed, or both.

[0057] It may be advantageous when the core layer comprises porous particles, particularly porous ceramic particles. Preferably, the particles have a plurality of micropores with an average diameter ranging from 1 micrometer to 10 micrometers, more preferably from 4 micrometers to 5 micrometers. That is, individual particles preferably have micropores. Preferably, the micropores are interconnected. They are preferably not confined to the surface of the particles, but are found to substantially cover the entire cross-section of the particles. Preferably, the particle size is from 200 micrometers to 900 micrometers, more preferably from 250 micrometers to 850 micrometers, especially from 250 micrometers to 500 micrometers or from 500 micrometers to 850 micrometers. Preferably, at least two different sizes of particles are used, preferably two. Preferably, small and / or large particles are used. Small particles may have a size range of 250 micrometers to 500 micrometers. Preferably, large particles have a diameter of 500 micrometers to 850 micrometers. The individual particle sizes may be substantially the same or two or more predetermined sizes. Alternatively, two or more different size ranges can be used with particles of various sizes within each range. Preferably, two different sizes or size ranges are used. Preferably, each particle comprises a plurality of microparticles, substantially each microparticle being partially fused to one or more adjacent microparticles to define a lattice that defines micropores. Each microparticle preferably has an average size of 1 micrometer to 10 micrometers, and an average of 4 to 5 micrometers. Preferably, the average size of the micropore is from 2 to 8 micrometers, most preferably 4 to 6 micrometers. The shape of the micropore can be irregular. Accordingly, the size of the micropore, and specifically the mesopore mentioned below, is determined by adding the widest diameter of the pore to the narrowest diameter of the pore and dividing by 2. Preferably, the ceramic material is uniformly distributed across the entire cross-section of the core layer, i.e., there are substantially no agglomerates of ceramic material. Preferably, the microparticles have an average size of at least 2 micrometers or 4 micrometers and / or less than 10 micrometers or less than 6 micrometers, most preferably 5 to 6 micrometers. This particle size range has been found to allow for the controlled formation of micropores.

[0058] The particles may also contain a plurality of substantially spherical mesopores with an average diameter of 10 to 100 micrometers. These substantially increase the total porosity of the ceramic material without impairing its mechanical strength. The mesopores are preferably interconnected via a plurality of micropores. That is, the mesopores can be fluidly connected to each other via the micropores. The average porosity of the ceramic material itself is preferably at least 50%, more preferably greater than 60%, and most preferably 70% to 75%. The ceramic material used to produce the particles can be any (non-toxic) ceramic known in the art, such as calcium phosphate and glass ceramics. The ceramic can be a silicate, although calcium phosphate is preferred, especially α- or β-tricalcium phosphate or hydroxyapatite, or mixtures thereof. Preferably, the mixture is hydroxyapatite and β-tricalcium phosphate, especially greater than 50% w / w β-tricalcium, preferably 85% β-tricalcium phosphate and 15% hydroxyapatite. The preferred material is 100% hydroxyapatite. Preferably, the cement composition or dry premix contains 15% to 30% particles by weight of the total dry weight of the composition or premix.

[0059] Porous particles can result in a lower average density of the core layer and thus a lighter weight, which is advantageous from an economic and processing perspective. Furthermore, the presence of porous particles in the core layer typically leads to an increase in porosity, at least to some extent, on the porous top and bottom surfaces of the core layer. This is beneficial for attaching additional layers to the top and / or bottom surfaces of the core layer, such as, for example, a primer layer, an adhesive layer (initially liquid), or another decorative or functional layer. Typically, these layers are initially applied in a liquid state, where the pores allow liquid substances to be drawn into (to permeate) the pores, which increases the contact surface area between the layers and thus improves the bonding strength between the layers.

[0060] The panel may comprise a layered structure, including, for example, a central core (or core layer) and at least one decorative top section, the decorative top section being directly or indirectly attached to the core layer, or integrally formed with the core layer, wherein the top section defines the top surface of the panel. The top section preferably comprises at least one decorative layer, the decorative layer being directly or indirectly attached to the 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 the decorative layer. The protective layer also becomes part of the decorative top section. The presence of the printed layer and / or the protective layer can prevent the tile from being scratched and / or damaged by environmental factors such as UV / moisture and / or abrasion. The printed layer may be formed from a film on which a decorative print is applied, wherein the film is attached to a base layer and / or an intermediate layer, such as a primer layer, located between the base layer and the decorative layer. The printed layer may also be formed of at least one ink layer, which is applied directly to the top surface of the core layer or applied to the primer layer, which is applied to the base layer. The panel may include at least one wear layer that is directly or indirectly attached to the upper surface of the decorative layer. The wear layer also becomes part of the decorative top section. Each panel may include at least one paint layer that is directly or indirectly attached to the upper surface of the decorative layer, preferably to the upper surface of the wear layer.

[0061] The lower (rear) side of the core (layer) may also constitute the lower (rear) side of the panel itself. However, it is conceivable, and even preferred, that the panel includes said lower side which is directly or indirectly fixed to the core. Typically, the back layer serves as a balancing layer to stabilize the shape of the panel itself, particularly its flatness. Furthermore, the back layer typically has sound-suppressing properties that contribute to the panel itself. Since the back layer is typically a sealing layer, applying the back layer to the lower side of the core will at least partially, preferably completely, cover the core recesses. Here, the length of each core recess is preferably less than the length of the back layer. The back layer may be provided with cutout portions, at least a portion of which overlaps with at least one core recess. At least one back layer is preferably at least partially made of a flexible material, preferably an elastomer. The thickness of the back layer typically varies from about 0.1 to 2.5 mm. Non-limiting examples of materials that may at least partially constitute the back layer are polyethylene, cork, polyurethane, polyvinyl chloride, and ethylene-vinyl acetate. Optionally, the backing layer comprises one or more additives, such as fillers (e.g., chalk), dyes, resins, and / or a variety of plasticizers. In certain embodiments, the backing layer is at least partially made of a composite material of resin-bonded, ground (or scraped) cork particles. Other tree-related products, such as wood, can be used instead of cork. The thickness of the polyethylene backing layer is typically, for example, 2 mm or less. The backing layer can be solid or foamed. A foamed backing layer can further improve sound-damping properties. A solid backing layer can improve the required balance and stability of the panel.

[0062] The inner sides of the upward tongue and the downward tongue can contact each other in the engaged state to transfer force between them, particularly from the upward tongue to the downward tongue. The inner sides of the tongues can contact at a tongue contact surface, wherein the tongue contact surface can be inclined. This inclination can cause a portion of the inner side of the upward tongue to tilt toward the flank, such that a tangent from the tongue contact surface intersects an inner vertical plane above the tongue contact surface. Alternatively, this inclination can cause a portion of the inner side of the tongue to tilt away from the upward flank, such that a tangent from the tongue contact surface intersects an inner vertical plane below the tongue contact surface. These are respectively a closed groove system and an open groove system. The closed groove system provides improved locking but is more difficult to engage, while the open groove system is easier to engage but does not provide the additional vertical locking of the closed groove system.

[0063] The first and second coupling members are disposed on opposite sides of the panel. The panel is, for example, rectangular, parallelogram, and / or elongated, and the first and second coupling members may be disposed on two opposite sides of such a panel (and thus on all four sides). Alternatively, the first and second coupling members may be provided only on one pair of opposite sides, and other coupling members, such as angled downward coupling members having lateral tongues and lateral grooves, may be provided on another pair of opposite sides.

[0064] The present invention further relates to a covering, particularly a floor covering, comprising a plurality of interconnected panels according to any one of the present inventions.

[0065] Preferred embodiments of the present invention are presented in the following group of non-limiting clauses. Clause 0066.

[0067] 1. A panel (1), particularly a floor panel, comprising: a. at least one first coupling member (2) and at least one second coupling member (3) disposed on opposite sides of the panel (1), wherein the first coupling member (2) of the panel and the second coupling member (3) of another panel (1) are configured to engage in a downward movement; b. The first connecting member (2) includes: an upward tongue (4), at least one upward wing (5) located at a distance from the upward tongue (4), and an upward groove (6) formed between the upward tongue (4) and the upward wing (5), wherein the upward groove (6) is adapted to receive at least a portion of the downward tongue (7) of the second connecting member (3) of the other panel (1), wherein the side of the upward tongue (4) facing the upward wing is the inner side (8) of the upward tongue (4), and the side of the upward tongue (4) away from the upward wing (5) is the outer side (9) of the upward tongue (4), wherein at least a portion of the inner side (8) of the upward tongue (4) is inclined toward the upward wing (5); c. The second connecting member (3) includes: a downward tongue (7), at least one downward wing (10) located at a distance from the downward tongue (7), and a downward groove (11) formed between the downward tongue (7) and the downward wing (10), wherein the downward groove (11) is adapted to receive at least a portion of the upward tongue (4) of the first connecting member (2) of the other panel (1), wherein the side of the downward tongue (7) facing the downward wing (10) is the inner side (12) of the downward tongue (7), and the side of the downward tongue (7) away from the downward wing (10) is the outer side (13) of the downward tongue (7), wherein at least a portion of the inner side (12) of the downward tongue (7) is inclined toward the downward wing (10); d. Wherein, the outer side (13) of the downward tongue (7) and the upward wing (5) both include an upper contact surface (14) near or toward the top of the panel (1), wherein at least one of the contact surfaces (14) preferably extends at least partially vertically, and in the engaged state of the panel (1), the upper contact surface (14) of the outer side (13) of the downward tongue (7) of the panel is configured to engage with the upper contact surface (14) of the upward wing (5) of the adjacent panel; e.Wherein, the outer side (9) of the upward tongue (4) includes: a first locking element (28), the first locking element (28) includes an outward protrusion, and wherein a second locking element (29) is provided on the downward side wing (10), the second locking element (29) includes a recess, wherein, in the combined state of adjacent panels, at least a portion of the first locking element (28) of the panel is in contact with at least a portion of the second locking element (29) of the other panel (1) to achieve a locking effect between the panels (1), preferably a vertical locking effect; f. wherein, the outer side of the outward protrusion (28) includes an upper part (31) and an adjacent lower part (32), wherein the lower part (32) includes an inclined locking surface (30a), and the upper part (31) includes a guide surface (32'), the guide surface (32') preferably being curved; g. wherein, the recess (29) includes an upper part (33) and an adjacent lower part (34), wherein the lower part includes an inclined locking surface (30b); h. In the coupled state of adjacent panels, the inclined locking surface (30a) of the lower portion (32) of the outwardly protruding (28) and the inclined locking surface (30b) of the lower portion (34) of the recessed (29) are in contact to achieve a locking effect between the panels (1), wherein, in the coupled state of adjacent panels (1), the upper portions (31, 33) of the first locking element (28) and the second locking element (29) are at least partially spaced apart.

[0068] 2. The panel (1) as described in Clause 1, wherein the entire inner side (8) of the upward tongue (4) is inclined toward the upward wing (5), and the entire inner side (12) of the downward tongue (7) is inclined toward the downward wing (10).

[0069] 3. The panel (1) as described in clause 1 or 2, wherein, in the combined state of adjacent panels, the upper portions (31, 33) of the first locking element (28) and the second locking element (29) are completely separated.

[0070] 4. The panel (1) as described in any of the preceding clauses, wherein, in the coupled state of adjacent panels, only a portion of the inclined locking surface (30a) of the lower portion (32) of the outwardly protruding (28) interacts with only a portion of the inclined locking surface (30b) of the lower portion (34) of the recess (29).

[0071] 5. The panel (1) as described in any of the preceding clauses, wherein at least a portion of the upper part (31) of the outward protrusion (28) is located at a height higher than the height defined by the lowest point of the upward groove (6), and wherein at least a portion of the upper part (33) of the recess (29) is located at a height higher than the height defined by the lowest point of the upward groove (6).

[0072] 6. The panel (1) as described in any of the preceding clauses, wherein the length of the inclined locking surface (30a) of the lower portion (32) of the outwardly protruding (28) is greater than the inclined locking surface (30B) of the lower portion (34) of the groove (29), preferably at least 1.5 times greater.

[0073] 7. The panel (1) as described in any of the preceding clauses, wherein the upper portion (31, 33) extends in a larger vertical cross section compared to the lower portion (32, 34), wherein, preferably, the height of the upper portion (31, 33) is at least three times the height of the lower portion (32, 34).

[0074] 8. The panel (1) as described in any of the preceding clauses, wherein the outer side (9) of the upward tongue (7) includes an upper outer portion (35) and a lower outer portion (36), wherein the first locking element (28) is disposed between the upper portion (35) and the lower outer portion (36), wherein the lower outer portion (36) is disposed closer to the inner side (8) of the upward tongue (4) than the upper outer portion (35).

[0075] 9. The panel (1) as described in Clause 8, wherein the upper outer portion (35) is preferably substantially vertical and defines an outer vertical plane (37), wherein the first locking element (28) protrudes at least partially from the outer vertical plane (37) in a horizontal direction, preferably at most 2 mm.

[0076] 10. The panel (1) as described in any of the preceding clauses, wherein the outer side (9) of the upward tongue (7) includes an upper outer portion (35) defining an outer vertical plane (37), wherein the first locking element (28) includes an outward protrusion (28), wherein the outer side of the outward protrusion (28) includes an upper portion (31) and an adjacent lower portion (32), wherein the upper portion (31) is entirely located on the side of the outer vertical plane (37) away from the upward wing, and wherein the lower portion (32) intersects the outer vertical plane (37).

[0077] 11. The panel (1) as described in Clause 10, wherein the inclined surface locking surface (30B) and the upper part (31) of the lower part (34) of the groove (29) are both located entirely on the side of the outer vertical plane (37) away from the upward wing.

[0078] 12. The panel (1) as described in any one of Clauses 10-11, wherein the lower outer portion (36) is preferably substantially vertical, and wherein the inclined locking surface (30A) or the lower portion (32) forms an angle (β) between 100 and 175 degrees with the lower outer portion (36).

[0079] 13. The panel (1) as described in any of the preceding clauses, wherein the outermost portion (38) of the first locking element (28) is disposed at a horizontal height lower than the upward groove (6).

[0080] 14. The panel (1) as described in any of the preceding clauses, wherein the upper contact surface (14) of the lower tongue (7) extends in a vertical direction, and wherein the upper contact surface (14) of the upper wing (5) is inclined downward away from the upper tongue (4), wherein, preferably, the angle between the vertical upper contact surface (14) of the lower tongue (7) and the inclined upper contact surface (14) of the upper wing (5) is between 0 and 2 degrees, preferably between 0 and 1 degree, and more preferably between 0 and 0.5 degrees.

[0081] 15. The panel (1) as described in any of the preceding clauses, wherein the upper contact surface (14) of the lower tongue (7) and the upper side wing (5) includes a third locking element, which is located below and preferably adjacent to the upper contact surface (14) of the lower tongue (7), and the upper side wing (5) includes a fourth locking element, which is located below and adjacent to the upper contact surface (14) of the upper side wing (5), wherein, in the combined state of adjacent panels, at least a portion of the third locking element of the panel and at least a portion of the second locking element of the other panel contact each other to achieve a locking effect of the panels relative to each other, preferably a vertical locking effect, and wherein, in the combined state of adjacent panels, the upper contact surface (14) defines an inner vertical plane (19), wherein the third locking element and the fourth locking element are located on the same side of the inner vertical plane (19) away from the upper tongue (4).

[0082] 16. The panel (1) as described in Clause 15, wherein the third locking element and the fourth locking element are located on a single and identical side of the inner vertical plane (19) opposite to the upward tongue (4).

[0083] 17. The panel (1) as described in any one of Clauses 15-16, wherein the third locking element and the fourth locking element extend at most 1 mm in the horizontal direction relative to the inner vertical plane (19), preferably at most 0.5 mm, and more preferably at most 0.2 mm.

[0084] 18. The panel (1) as described in any one of clauses 15-17, wherein the third locking element includes a protrusion and wherein the fourth locking element includes a recess.

[0085] 19. The panel (1) as described in any one of Clauses 15-18, wherein the height of the third locking element and the fourth locking element is higher than the height of the highest point of the upward tongue (4).

[0086] 20. The panel (1) as described in any one of Clauses 15-19, wherein the first locking element (28) and the second locking element (29) are located at a height lower than that of the third locking element and the fourth locking element.

[0087] 21. The panel (1) as described in any of the preceding clauses, wherein the outer side of the downward tongue (7) includes at least one recess between the upper contact surface (14) and the third locking element of the downward tongue (7), wherein, in the engaged state of adjacent panels, the recess is preferably located at a distance from the upper contact surface (14) of the upward wing (5).

[0088] 22. The panel (1) as described in any of the preceding clauses, wherein the downward tongue (7) and the upward wing (5) each include an inclined contact surface (15) adjacent to their upper contact surface (14), wherein the inclined contact surface (15) of the downward tongue (7) of the panel is configured to engage the inclined contact surface (15) of the upper wing (5) of the adjacent panel in the coupled state of the panel (1), wherein a portion of each vertical upper contact surface (14) and each adjacent inclined surface (15) form an angle (α) between 100 and 175 degrees with each other.

[0089] 23. The panel (1) as described in Clause 22, wherein the inclined contact surface (15) of the downward tongue (7) extends at most 1 mm, preferably at most 0.5 mm, and more preferably at most 0.2 mm in the horizontal direction relative to the inner vertical plane (19), the inner vertical plane (19) being defined by the upper contact surfaces (14) of the two panels in the coupled state.

[0090] 24. The panel (1) as described in Clause 22 or 23, wherein the height of the inclined contact surfaces (15A, 15B) of the lower tongue (7) and the upper wing (5) is higher than the height of the highest point of the upper tongue (4).

[0091] 25. The panel (1) as described in any one of Clauses 15-20 and any one of Clauses 22-24, wherein the inclined contact surface (15) of the downward tongue defines at least a portion of the third locking element, wherein the inclined contact surface (15) of the upward wing (5) defines at least a portion of the fourth locking element.

[0092] 26. The panel (1) as described in any one of clauses 22-25, wherein the downward tongue (7) includes an outer surface (16) which is located below and adjacent to the inclined contact surface (15) of the downward tongue (7), and the upward wing (5) includes an inner surface (17) which is located below and adjacent to the inclined contact surface (15) of the upward wing (5), wherein the outer surface (16) and the inner surface (17) are substantially parallel, preferably extending at least partially in a vertical direction and / or at least partially curved.

[0093] 27. A panel (1) as described in any one of clauses 22-26, wherein, in the combined state of adjacent panels, an upper contact surface (14) defines an inner vertical plane (19), wherein inclined contact surfaces (15a, 15b) are located on the same side of the inner vertical plane (19).

[0094] 28. The panel (1) as described in any one of clauses 22-27, wherein, in the combined state of adjacent panels, the upper contact surface (14) defines an inner vertical plane (19), wherein the inclined contact surfaces (15a, 15b) are located on a single and identical side of the inner vertical plane (19).

[0095] 29. The panel (1) as described in any one of clauses 22-28, wherein the length of the inclined contact surface (15) of the upward wing (5) exceeds the length of the inclined contact surface (15) of the downward tongue (7), wherein preferably, the length of the inclined contact surface (15) of the upward wing (5) is at least twice the length of the inclined contact surface (15) of the downward tongue (7).

[0096] 30. A panel (1) as described in any one of clauses 22-29, wherein, in the coupled state of adjacent panels, an upper contact surface (14) defines an inner vertical plane (19), wherein a portion (20) of the lower tongue (7), including its inclined contact surface (15a), extends beyond the inner vertical plane (19), wherein said portion (20) is substantially trapezoidal or wedge-shaped.

[0097] 31. The panel (1) as described in Clause 30, wherein the height of said portion (20) exceeds the width of said portion, wherein, preferably, the maximum height of said portion (20) is at least three times the maximum width of said portion (20).

[0098] 32. The panel (1) as described in clause 30 or 31, wherein the width of the space (18) is equal to or greater than the width of the portion (20) of the downward tongue (20).

[0099] 33. The panel (1) as described in any one of clauses 30-32, wherein, in the combined state of adjacent panels, the upper contact surface (14) defines the inner vertical plane (19), wherein the inclined contact surface (15) is adjacent to the inner vertical plane (19).

[0100] 34. The panel (1) as described in any one of clauses 30-33, wherein the angle (α) formed by the upper contact surface and the inclined contact surface is within 20 degrees different from the angle (β) formed by the lower outer portion (36) and the inclined locking surface (30A) or the lower portion (32), preferably the same.

[0101] 35. The panel (1) as described in any of the preceding clauses, wherein, in the combined state of adjacent panels, a space (18) exists between at least a portion of the outer surface (16) of the panel (1) and at least a portion of the inner surface (17) of the adjacent panel (1).

[0102] 36. The panel (1) as described in any of the preceding clauses, wherein, in the coupled state of adjacent panels, the bottom (21) of the downward tongue (7) is in contact with the upper side (22) of the upward groove (6) at the groove contact surface (23), and wherein the gap (24) exists between the first coupling member (2) and the second coupling member (3) and extends from the inclined contact surface (15) to the groove contact surface (23).

[0103] 37. The panel (1) as described in any of the preceding clauses, wherein, in the coupled state of adjacent panels, the bottom (21) of the downward tongue (7) contacts the upper side (22) of the upward groove (6) at the groove contact surface (23), wherein the groove contact surface (23) is preferably substantially horizontal, and wherein there is a gap (24) on both sides of the groove contact surface (23) between the first coupling member (2) and the second coupling member (3).

[0104] 38. The panel (1) as described in any of the preceding clauses, wherein, in the engaged state, the upper surface (25) of the upward tongue (4) and the upper surface (26) of the downward groove (11) are at least partially separated from each other, such that there is a gap (27) between the two surfaces (25, 26).

[0105] 39. The panel (1) as described in any of the preceding clauses, wherein the upper contact surface (14) of the upward side wing (5) and the inclined contact surface (15) form a first angle with each other, and the upper contact surface (14) and the inclined contact surface (15) of the downward tongue (7) form a second angle with each other, wherein the difference between the first angle and the second angle is within 20 degrees.

[0106] 40. The panel (1) as described in any of the preceding clauses, wherein the outer side of the downward tongue (7) includes at least one recess between the upper contact surface (14) and the inclined contact surface (15a) and / or the third locking element, wherein, in the engaged state of adjacent panels, the recess is preferably located at a distance from the upper contact surface (14) of the upward wing (5).

[0107] 41. The panel (1) as described in any of the preceding clauses, wherein the outer side (9) of the upward tongue (7) includes an upper outer portion (35) that defines an outer vertical plane (37) that divides the upward tongue (4) into an inner section pointing to an upward wing (6) and an outer section including a first locking element (28), wherein the maximum width of the inner section is at least 8 times, preferably at least 10 times, the width of the outer section.

[0108] 42. A panel (1) as described in any of the preceding clauses, wherein the panel includes at least one third coupling member and at least one fourth coupling member disposed on another pair of opposite sides of the panel (1), wherein the third coupling member of the panel and the fourth coupling member of the other panel (1) are preferably configured to engage by downward angular movement.

[0109] 43. The panel (1) according to clause 42, wherein the third coupling member comprises: • a lateral tongue extending in a direction substantially parallel to the upper side of the core, • at least one second downward wing located at a distance from the lateral tongue, • a second downward groove formed between the lateral tongue and the second downward wing, and wherein the fourth coupling member comprises: • a third groove configured to receive at least a portion of the lateral tongue of the third coupling profile of an adjacent panel, the third groove being defined by an upper lip and a lower lip, wherein the lower lip is provided with an upward locking element, wherein the third coupling member and the fourth coupling member are configured such that two of such panels can be coupled to each other by rotational movement, wherein, in the coupled state: at least a portion of the lateral tongue of the first panel is inserted into the third groove of the adjacent second panel, and wherein at least a portion of the upward locking element of the second panel is inserted into the second downward groove of the first panel.

[0110] 44. The panel (1) according to any one of the preceding clauses, wherein the panel (1) is a decorative panel, comprising: • at least one core layer, and • at least one decorative top section which is directly or indirectly fixed to the core layer, wherein the top section defines the top surface of the panel, and • a plurality of sides which are at least partially defined by the core layer and / or by the top section, wherein at least two opposing sides are provided with a first connecting member and a second connecting member, respectively.

[0111] 45. A covering, particularly a floor covering, comprising a plurality of interconnected panels (1) as described in any of the preceding clauses.

Implementation Method

[0112] Figure 1 shows a floor panel (1), which includes a first connecting member (2) and a second connecting member (3) in a connected state. The first connecting member (2) includes: an upward tongue (4); an upward wing (5) located at a distance from the upward tongue (4); and an upward groove (6) formed between the upward tongue (4) and the upward wing (5), wherein the upward groove (6) is adapted to the downward tongue (7) of the second connecting member (3) of the other panel (1). The side of the upward tongue (4) facing the upward wing is the inner side (8) of the upward tongue (4), and the side of the upward tongue (4) away from the upward wing (5) is the outer side (9) of the upward tongue (4).

[0113] The second connecting member (3) includes: a downward tongue (7); a downward side wing (10) located at a distance from the downward tongue (7); and a downward groove (11) formed between the downward tongue (7) and the downward side wing (10). The side of the downward tongue (7) facing the downward side wing (10) is the inner side (12) of the downward tongue (7), and the side of the downward tongue (7) away from the downward side wing (10) is the outer side (13) of the downward tongue (7).

[0114] The outer side (13) of the downward tongue (7) and the upward wing (5) both include an upper contact surface (14) located at the top of the panel (1), the upper contact surfaces (14) of both extending vertically in contact. The downward tongue (7) and the upward wing (5) both include an inclined contact surface (15) adjacent to their upper contact surface (14), the inclined contact surfaces (15) of both being in contact, wherein the upper contact surface (14) at one end and the inclined contact surface (15) of the upward wing (5) and / or the outer side (13) of the downward tongue (7) preferably form an angle (α) of approximately 125 degrees with each other. The upper contact surface (14) and the inclined contact surface (15) of the upward wing (5) form a first angle of approximately 125 degrees with each other, and the upper contact surface (14) and the inclined contact surface (15) of the downward tongue (7) form a second angle of approximately 125 degrees with each other.

[0115] The downward tongue (7) includes an outer surface (16) adjacent to its inclined contact surface (15), and the upward wing (5) includes an inner surface (17) adjacent to its inclined contact surface (15), wherein the outer surface (16) and the inner surface (17) are parallel and perpendicular. There is a space (18) between the outer surface (16) and the inner surface (17).

[0116] The upper contact surface (14) defines the inner vertical plane (19), wherein the inclined contact surface (15) of the lower tongue (7) extends beyond the inner vertical plane (19), and the inclined contact surface (15) of the upper wing (5) is located inside the inner vertical plane (19). A portion (20) of the lower tongue (7) extends beyond the inner vertical plane (19), wherein the portion (20) is generally trapezoidal or wedge-shaped. The inclined contact surfaces (15) are all arranged completely outside the inner vertical plane (19) and adjacent to the inner vertical plane (19). The portion (20) is an extension having a vertical portion larger than the horizontal portion.

[0117] The bottom (21) of the downward tongue (7) contacts the upper side (22) of the upward groove (6) at the groove contact surface (23), wherein there is a gap (24) between the first connecting member (2) and the second connecting member (3). The gap (24) extends from the inclined contact surface (15) to the groove contact surface (23). In addition, the upper surface (25) of the upward tongue (4) and the upper surface (26) of the downward groove (11) are spaced apart from each other, such that a gap (27) exists between the two surfaces (25, 26).

[0118] The outer side (9) of the upward tongue (4) includes a first locking element (28) in the form of an outward protrusion, and a second locking element (29) in the form of a recess is provided on the downward side wing (10), wherein at least a portion of the first locking element (28) and the second locking element (29) are in contact and form a locking element surface (30).

[0119] Figures 2 and 3 show the first and second coupling components, respectively. The outer side of the outwardly protruding (28) includes an upper portion (31) and an adjacent lower portion (32), wherein the lower portion (32) includes an inclined locking surface (30a), and the upper portion (31) includes a curved guide surface (32'). The recess (29) includes an upper portion (33) and an adjacent lower portion (34), wherein the lower portion includes an inclined locking surface (30B). Compared with the lower portions (32, 34), the upper portions (31, 33) extend over a larger vertical segment.

[0120] The part in contact between the first locking element (28) and the second locking element (29) is the inclined locking surface (30, 30A, 30B) of the locking elements (28, 29), and the upper parts (31, 33) of the first locking element (28) and the second locking element (29) are at least partially spaced apart.

[0121] The outer side (9) of the upward tongue (7) includes an upper outer portion (35) and a lower outer portion (36), wherein the first locking element (28) is disposed between the upper outer portion (35) and the lower outer portion (36). The lower outer portion (36) is disposed closer to the inner side (8) of the upward tongue (4) than the upper outer portion (35).

[0122] The upper outer portion (35) is substantially vertical and defines an outer vertical plane (37), wherein the first locking element (28) protrudes from the outer vertical plane (37). The lower outer portion (36) is substantially vertical, and the inclined locking surface (30A) or the lower portion (32) forms an angle (β) between 100 degrees and 175 degrees with the lower outer portion (36). The angle (α) formed by the upper contact surface and the inclined contact surface is approximately the same as the angle (β) formed by the lower outer portion (36) and the inclined locking surface (30A) or the lower portion (32).

[0123] The outermost part (38) of the first locking element (28) is positioned at a lower horizontal height than the upward groove (6).

[0124] Figure 4 schematically illustrates an embodiment of two interconnected panels (1) having a first connecting member and a second connecting member according to the present invention. The panel (1) comprises a first connecting member (2) and a second connecting member (3) in a joined state. The illustrated embodiment includes all the features shown in Figure 1 and further includes a recess (40) located below the upper contact surface (14a) of the second connecting member (3). The recess (40) comprises an upper inclined surface and a lower inclined surface. The lower inclined surface is aligned with the inclined contact surface (15a) of the downward tongue (7). The recess (40) can serve as an expansion chamber to allow the panel material to expand, for example, upon exposure to heat and / or moisture, and further, to reduce the contact surface area at the top seam between the two panels (1), which allows the clamping force to be more significantly present at the top seam between the panels (1) to improve the water-resistant properties of the panel joint itself.

[0125] FIG5 schematically shows a detailed view of part A of the embodiment shown in FIG4, surrounding the upper contact surfaces of two interconnected panels. The figure shows two contact points or areas (41, 42), in which the engagement force (or clamping force) of the connecting parts (2, 3) in this particular area is higher than the engagement force (or clamping force) of the other parts shown in this figure. These two closely contacting points or areas (41, 42) result in significantly improved water resistance and thus further improve the waterproof connection between the panels (1). This figure shows that the upper contact area 14b is not completely parallel to the upper contact area 14a, but is slightly inclined relative to the opposite vertical upper contact area 14a, and more specifically extends (slightly) in a downward direction away from the vertical upper contact area 14a. This does not necessarily mean that the upper contact areas 14a and 14b will become separated from each other in the downward direction, but it usually results in a tighter connection between the upper parts of the upper contact areas 14a and 14b than between the lower parts of the upper contact areas 14a and 14b.

[0126] It is conceivable that, due to the locking force, during the engagement process of adjacent inclined contact surfaces, elastic or plastic deformation occurs at or around the inclined contact surface 15a of the downward tongue. The area at or around the inclined contact surface 15b may also undergo localized elastic or plastic deformation.

[0127] FIG6 schematically shows a detailed view of part B of the embodiment shown in FIG4 of the interlocking elements (28, 29) of two interconnected panels, and FIG6 surrounds the interlocking elements (28, 29) of the two interconnected panels.

[0128] The upper outer portion (35) is substantially vertical and defines an outer vertical plane (37), wherein the first locking element (28) protrudes from the outer vertical plane (37). The distance (39a) between the outermost portion (38) of the first locking element (28) and the outer vertical plane (37) is substantially half the distance (39b) between the outermost portion of the second locking element (29) and the vertical plane (37). The distance 39b is preferably less than 0.75 mm and the distance 39a is preferably less than 0.375 mm. In one embodiment, the horizontal distance between the outer vertical plane (37) and the upper contact surface is distance D. The distance 39b may be approximately 0.4 times the distance D and the distance 39a may be approximately 0.2 times the distance D.

[0129] Ordinal numbers used in this document, such as "first," "second," "third," etc., are for identification purposes only. The panel according to the invention may also be called a ceramic tile. The core (layer) of the panel may also be called a base (layer) and may consist of a plurality of sublayers, which may include, for example, reinforcing layers, such as fiberglass layers. The bonding components may also be called bonding profiles or connecting profiles. "Complementary" bonding profiles mean that these bonding profiles can fit together. However, for this purpose, complementary bonding profiles do not necessarily have to be complementary in form. Locking in the "vertical direction" means locking in a direction perpendicular to the plane of the panel. Locking in the "horizontal direction" means locking in a direction perpendicular to the individual bonding edges of the two panels and parallel to or descending with the plane defined by the panel. In the context of this document, the expressions "foamed composite material" and "foamed plastic material" (or "foamed plastic material") are interchangeable, wherein a foamed composite material actually comprises a foamed mixture comprising at least one (thermo)plastic material and at least one filler (non-polymeric material).

[0130] The above-described inventive concepts have been illustrated through several illustrative embodiments. It is conceivable that individual inventive concepts may be applied, and other details of the described examples may also be applied without doing so. It is not necessary to describe in detail all possible combinations of the above-described inventive concepts, as those skilled in the art to which this invention pertains will understand that many inventive concepts can be (re)combined to achieve a particular application.

[0131] The verb “to contain” and its conjugations used in this patent publication are understood not only to mean “to contain”, but also to mean the phrases “containing”, “substantially composed of”, “formed by” and their conjugations. [Simplified Explanation of the Diagram]

[0133] The invention will now be explained based on non-limiting exemplary embodiments shown in the following figures. Corresponding elements are represented by corresponding element symbols in the figures. In the figures: [Figure 1] Schematively shows two interconnected panels having a first connecting member and a second connecting member according to the invention. [Figure 2] Schematably shows the first connecting member portion of the panel according to the invention and Figure 1. [Figure 3] Schematably shows the second connecting member portion of the panel according to the invention and Figure 1. [Figure 4] Schematably shows an embodiment of two interconnected panels having a first connecting member and a second connecting member according to the invention. [Figure 5] Schematably shows a detailed view of part A of the embodiment shown in Figure 4. [Figure 6] Schematably shows a detailed view of part B of the embodiment shown in Figure 4.

Claims

1. A panel (1), comprising: a. At least one first connecting member (2) and at least one second connecting member (3) disposed on opposite sides of the panel (1), wherein the first connecting member (2) of the panel and the second connecting member (3) of the other panel (1) are configured to engage in a downward movement; b. wherein the first connecting member (2) includes: an upward tongue (4), at least one upward wing (5) located at a distance from the upward tongue (4), and an upward groove (6) formed between the upward tongue (4) and the upward wing (5), wherein the upward groove (6) is adapted to receive at least a portion of the downward tongue (7) of the second connecting member (3) of the other panel (1), wherein the side of the upward tongue (4) facing the upward wing is the inner side (8) of the upward tongue (4), and the side of the upward tongue (4) away from the upward wing (5) is the outer side (9) of the upward tongue (4), wherein at least a portion of the inner side (8) of the upward tongue (4) is inclined toward the upward wing (5); c. The second connecting member (3) includes: a downward tongue (7), at least one downward wing (10) located at a distance from the downward tongue (7), and a downward groove (11) formed between the downward tongue (7) and the downward wing (10), wherein the downward groove (11) is adapted to accommodate at least a portion of the upward tongue (4) of the first connecting member (2) of the other panel (1), wherein the side of the downward tongue (7) facing the downward wing (10) is the inner side (12) of the downward tongue (7), and the side of the downward tongue (7) away from the downward wing (10) is the outer side (13) of the downward tongue (7), wherein at least a portion of the inner side (12) of the downward tongue (7) is inclined toward the downward wing (10); d. Wherein, the outer side (13) of the downward tongue (7) and the upward wing (5) both include an upper contact surface (14) near or toward the top of the panel (1), and in the coupled state of the panel (1), the upper contact surface (14) of the outer side (13) of the downward tongue (7) of the panel is configured to engage with the upper contact surface (14) of the upward wing (5) of the adjacent panel; e. Wherein, the outer side (9) of the upward tongue (4) includes: a first locking element (28), the first locking element (28) including an outward protrusion, and wherein the downward wing (10) is provided with a second locking element (29), the second locking element (29) including a recess, wherein, in the coupled state of the adjacent panels, at least a portion of the first locking element (28) of the panel is in contact with at least a portion of the second locking element (29) of the other panel (1) to achieve a locking effect between the panels (1); f.Wherein, the outer side of the outward protrusion (28) includes a curved upper portion (31) and an adjacent lower portion (32), wherein the lower portion (32) includes a planar inclined locking surface (30A), and the upper portion (31) includes a curved guiding surface (32'), wherein the inclined locking surface (30A) forms a crease with the curved upper portion (31); g. wherein, the recess (29) includes a curved upper portion (33) and an adjacent lower portion (34), wherein the lower portion includes a planar inclined locking surface (30B), wherein the inclined locking surface (30B) forms a crease with the curved upper portion (33); h. Wherein, in the coupled state of adjacent panels, the inclined locking surface (30A) of the lower part (32) of the outwardly protruding (28) and the inclined locking surface (30B) of the lower part (34) of the recessed (29) are in contact to achieve a locking effect between the panels, and wherein, in the coupled state of adjacent panels (1), the upper parts (31, 33) of the first locking element (28) and the second locking element (29) are at least partially spaced apart.

2. The panel (1) as described in claim 1, wherein, The entire inner side (8) of the upward tongue (4) is inclined toward the upward wing (5), and the entire inner side (12) of the downward tongue (7) is inclined toward the downward wing (10).

3. The panel (1) as described in claim 1 or 2, wherein, When adjacent panels are joined together, the upper parts (31, 33) of the first locking element (28) and the second locking element (29) are completely separated.

4. The panel (1) as described in claim 1, wherein, In the combined state of adjacent panels, only a portion of the inclined locking surface (30A) of the lower part (32) of the outward protrusion (28) and only a portion of the inclined locking surface (30B) of the lower part (34) of the recess (29) work together.

5. The panel (1) as described in claim 1, wherein, At least a portion of the upper part (31) of the outward protrusion (28) is located at a height higher than the height defined by the lowest point of the upward groove (6), and at least a portion of the upper part (33) of the recess (29) is located at a height higher than the height defined by the lowest point of the upward groove (6).

6. The panel (1) as described in claim 1, wherein, The outer side (9) of the upward tongue (4) includes an upper outer portion (35) and a lower outer portion (36), wherein the first locking element (28) is disposed between the upper outer portion (35) and the lower outer portion (36), wherein the lower outer portion (36) is disposed closer to the inner side (8) of the upward tongue (4) than the upper outer portion (35).

7. The panel (1) as described in claim 1, wherein, The outer side (9) of the upward tongue (4) includes an upper outer portion (35) that defines an outer vertical plane (37), wherein the first locking element (28) includes an outward protrusion (28), wherein the outer side of the outward protrusion (28) includes an upper portion (31) and an adjacent lower portion (32), wherein the upper portion (31) is located entirely on the side of the outer vertical plane (37) opposite to the upward wing, and wherein the lower portion (32) intersects the outer vertical plane (37).

8. The panel (1) as described in claim 1, wherein, The outermost portion (38) of the first locking element (28) is positioned at a lower horizontal height than the upward groove (6).

9. The panel (1) as described in claim 1, wherein, The upper contact surface (14) of the downward tongue (7) extends in a vertical direction, and the upper contact surface (14) of the upward wing (5) is inclined downward away from the upward tongue (4).

10. The panel (1) as described in claim 1, wherein, Below the upper contact surface (14) of the downward tongue (7) and the upward wing (5), the outer side of the downward tongue (7) includes a third locking element (20) and the upward wing (5) includes a fourth locking element (18), wherein, in the combined state of adjacent panels, at least a portion of the third locking element (20) of the panel and at least a portion of the fourth locking element (18) of the other panel are in contact to achieve a locking effect between the panels, and wherein, in the combined state of adjacent panels, the upper contact surface (14) defines an inner vertical plane (19), wherein the third locking element (20) and the fourth locking element (18) are located on the same side of the inner vertical plane (19) away from the upward tongue (4).

11. The panel (1) as described in claim 10, wherein, The third locking element (20) and the fourth locking element (18) are located on the same single side of the inner vertical plane (19) away from the upward tongue (4).

12. The panel (1) as described in claim 1, wherein, The outer side (9) of the upward tongue (4) includes an upper outer portion (35) that defines an outer vertical plane (37) that divides the upward tongue (4) into an inner segment and an outer segment. The inner segment faces the upward wing (5), and the outer segment includes the first locking element (28). The maximum width of the inner segment is at least 8 times the maximum width of the outer segment.

13. The panel (1) as described in claim 1, wherein, The panel includes at least one third coupling member and at least one fourth coupling member disposed on another pair of opposite sides of the panel (1).

14. The panel (1) as described in claim 1, wherein, The panel (1) is a decorative panel, comprising: at least one core layer; at least one decorative top section which is directly or indirectly fixed to the core layer, wherein the top section defines the top surface of the panel; and a plurality of sides which are at least partially defined by the core layer and / or the top section, wherein the first connecting member and the second connecting member are respectively provided on at least two opposite sides.

15. A covering comprising a plurality of interconnected panels as described in any one of claims 1 to 14 (1).

Images