EA045402B1 - PANEL AND COVERING - Google Patents

Description

The present invention relates to a panel such as a floor panel, in particular a decorative floor panel. The invention also relates to a covering, in particular a floor covering, comprising a plurality of interconnected panels according to the invention.

Recent decades have seen tremendous progress in the flooring market. Floor panels are known to be installed onto the subfloor in a variety of ways. It is known, for example, that floor panels are attached to the subfloor either by gluing or by nailing. The disadvantage of this technology is that it is quite complex and subsequent changes can only be made by breaking out the floor panels. In an alternative installation method, the floor panels are laid loosely on the subfloor, with the floor panels mutually aligned with each other through a tongue and groove joint, and in most cases they are also glued together at the tongue and groove joint. The floor obtained in this way, also called floating parquet flooring, has the advantage that it is easy to lay and that the entire surface of the floor can be moved, which is often convenient to obtain possible expansion and contraction phenomena. Examples of known floor panels are described in US2018/094441, WO2017/115202, WO2019/137964 and EP3031998.

Flooring options and requirements have also changed. While flooring used to be made from wood or wood-derived products, the market has recently evolved towards plastic-based panels such as PVC panels, and even mineral-based panels such as magnesium oxide panels. Each of these alternatives has its own advantages and disadvantages. One disadvantage is that it can be difficult to connect and secure the panels together, and to secure them in such a way that a watertight connection is made between the panels.

It is therefore an object of the present invention to provide an improved connection between panels, in particular a watertight connection.

According to the present invention, there is provided a panel, in particular a (decorative) floor panel, comprising at least one first connecting part and at least one second connecting part located on opposite sides of the panel, wherein the first connecting part of said panel and the second connecting part a portion of the other panel is preferably configured to be connected by a downward movement. Preferably, the first connecting portion includes an upward tongue, at least one upward side surface spaced from the upward tongue, and an upward groove formed between the upward tongue and the upward side surface, wherein the upward groove is configured with being capable of receiving at least a portion of a downward tongue of the second connecting portion of the other panel, wherein the side of the upward tongue facing the upward side surface is an inner side of the upward tongue, and the side of the upward tongue facing away from the upward side surface is the outer side of the tongue pointing upward; wherein the second connecting portion comprises a downward tongue, at least one downward side surface located at a distance from the downward tongue, and a downward groove formed between the downward tongue and the downward side surface, wherein the downward tongue is configured with capable of receiving at least a portion of an upward tongue of the first connecting portion of the other panel, wherein a side of the downward tongue facing the downward side surface is an inner side of the downward tongue, and a side of the downward tongue facing away from the downward side surface , is the outer side of the downward-facing tongue; wherein both the outer side of the downwardly directed tongue and the upwardly directed side surface comprise an upper contact surface adjacent to, or on, adjacent to, or directed towards the top side of the panel, wherein preferably at least one of said contact surfaces extends vertically , at least partially, and preferably completely, and wherein the upper contact surface of the outer side of the downwardly directed tongue of said panel is configured to engage with the upper contact surface of the upwardly directed side surface of the adjacent panel in the connected state of said panels; wherein the lower, preferably adjacent, upper contact surfaces of both the downward tongue and the upward side surface comprise an inclined contact surface, wherein the inclined contact surface of the downward tongue of said panel is configured to engage the inclined contact surface of the upwardly directed side surface of the adjacent panel in the connected state of said panels, each vertical portion of the upper contact surface and each adjacent inclined surface mutually form an angle (α) from 100 to 175 degrees; wherein the downwardly directed tongue adjacent to the inclined contact surface comprises an outer surface located below the inclined contact surface of the downwardly directed tongue, and wherein the upwardly directed side surface adjacent to the inclined contact surface comprises an inner surface located below the upwardly directed inclined contact surface

- 1 045402 side surface, wherein the outer and inner surfaces extend substantially parallel and extend at least partially in the vertical direction; wherein, in the connected state of the adjacent panel, there is a space between at least part of the outer surface of said panel and at least part of the inner surface of the adjacent panel.

It can be imagined that both upper contact surfaces extend partially or completely in a vertical direction. It may be preferable that the upper contact surface of the downward tongue extends in a vertical direction, while the upper contact surface of the upward side surface is inclined downwardly in a direction away from the upward tongue. Preferably, the vertical upper contact surface of the downward tongue and the inclined upper contact surface of the upward side surface form an angle of 0 to 2 degrees, preferably 0 to 1 degree, more preferably 0 to 0.5 degrees, even more preferably 0 to 0. ,3 degrees. It can also be envisioned that the upper contact surface of the upwardly directed tongue extends in a vertical direction, and wherein the upper contact surface of the downwardly directed tongue is inclined downwardly towards the downwardly directed side surface. Preferably, the inclined upper contact surface of the downward tongue and the vertical upper contact surface of the upward side surface form an angle of 0 to 2 degrees, preferably 0 to 1 degree, more preferably 0 to 0.5 degrees, even more preferably 0 to 0. ,3 degrees. It is further possible for each of the upper contact surface of the downward tongue and the upper contact surface of the upward side surface to be at least partially inclined with respect to a vertical plane (ie, a plane perpendicular to the panels). This inclination is preferably such that both upper contact surfaces are inclined downwardly away from each other. The technical effect of these embodiments is that in the top seam formed between the panels, more intense contact between the top contact surfaces can be realized, which helps to create a waterproof barrier. Additionally, the aforementioned tilt usually reduces sensitivity to tolerances and precision in manufacturing and joining. The slightly angled top contact surface prevents squeaking between interconnected panels. The slope further provides a stronger or better connection between the joined panels at the top, where the panels are designed to be in full contact when joined.

It should be noted that when describing the invention, terms such as top, bottom, top, bottom, horizontal and vertical are used depending on the flooring configuration, with the side facing up being the top or top side, the side on the subfloor being the bottom or bottom side and the panels lie horizontally or in a horizontal plane. When used as wall covering, which is also possible with the panels according to the present invention, the panels are usually mounted vertically. The side facing the wall is the bottom, the side facing the room is the top, and the vertical and horizontal sides are reversed. The wall panels themselves can also be appreciated lying on the floor, as if they were lying as floor panels. The same applies to ceiling coverings, which is also possible with the panels according to the present invention, in which the panels are mounted on the ceiling. Then the top and bottom are swapped. The ceiling panels themselves can also be appreciated lying on the floor, as if they were lying as floor panels.

The connecting parts of the two panels interact and provide fixation of the panels, usually in the horizontal and vertical directions. An upward-facing tongue fits into a downward-facing groove, and a downward-facing tongue fits into an upward-facing groove, providing fixation in the plane of a panel or horizontal direction, such as for floor coverings.

The panels are usually designed in such a way that they are connected in a downward direction. This movement is also called a falling or vertical movement and can mean that a new panel can be inserted into an already placed panel. This connection is also possible when the panels are connected using a snap or scissor motion. Alternatively, the panels can be positioned so that they are connected in an oblique (downwards) motion. This motion can also be called a rotary motion, in which a portion of the new panel is inserted into a portion of an already placed panel and is fully inserted through an inclined motion. In a preferred embodiment, the panel includes at least one third connecting portion and at least one fourth connecting portion located on another pair of opposite sides of the panel, wherein the third connecting portion of said panel and the fourth connecting portion of the other panel are preferably configured to be connected by an inclined downward movements. Preferably, the third connecting portion comprises: a laterally directed tongue extending in a direction substantially parallel to the upper side of the core, at least one second downwardly directed side surface spaced from the sidewardly directed tongue, and a second downwardly directed groove formed between the sidewardly directed a tongue and a second downwardly directed side surface, and wherein the fourth connecting portion comprises: a third groove configured to receive at least a portion of the sideways directed tongue of a third connecting profile of an adjacent panel, said third groove being defined by an upper lip and a lower lip, wherein said lower lip is provided with an upwardly directed locking element, wherein the third connecting part and the fourth connecting part are configured such that two such panels are capable of being connected to each other by means of a rotary movement, wherein in the connected state: at least part a laterally directed tongue of the first panel is inserted into a third groove of the adjacent second panel, and wherein at least a portion of an upwardly directed locking member of said second panel is inserted into a second downwardly directed groove of said first panel.

To form a tight connection at the top, the panels are in contact with the upper contact surfaces. Preferably, these upper contact surfaces are plane-parallel and extend vertically to increase the contact surface. The top contact surfaces are not necessarily the top surfaces of the panels; for example, it is possible to provide the panels with a chamfered or chamfered top surface or grout that will serve a decorative function on the surface of the panels. Preferably, the upper contact surfaces are the upper surfaces on which the two panels are in contact.

In addition, in one embodiment, the outer side of the downward tongue comprises between the upper contact surface and the inclined contact surface of the downward tongue at least one recess, preferably in the shape of a trapezoid, wherein in the connected state of adjacent panels, said recess is preferably located at a distance from the top contact surface of the upward-facing side surface.

Said recess allows for (local) expansion or swelling of the panel material, preventing the joint between two interconnected panels from breaking or moving. The recess also acts as an additional dust chamber, preventing dust from entering the contact of the upper contact surfaces. The recess may be located between the upper contact surface of the downward tongue and the inclined contact surface of the downward tongue or at the transition of the upper contact surface and the inclined contact surface.

Preferably, the panels or connecting parts of the panels are designed in such a way that, in the connected state, they exert a certain locking force, pressing the panels against each other. Such locking force can be achieved, for example, by a pre-tensioned configuration or by slightly increasing the size of one connecting portion relative to the other. In floor panels, this creates a force in the horizontal direction or plane of the floor panel.

This locking force preferably presses the panels against each other in the main plane of the panels and thereby presses the upper contact surfaces against each other, this pre-tension improving the connection between the panels and preferably creating a watertight seal on the top of the panels.

It is possible that, due to the locking force or clamping force, the area or area on or around the inclined contact surface of the downward tongue is elastically or plastically deformed during engagement of adjacent inclined contact surfaces. The type of deformation degree usually depends on the characteristics of the panel material and the specific design of the connecting parts.

There is an inclined contact surface adjacent to the upper contact surfaces, and usually immediately adjacent to or immediately below them. On inclined surfaces, the panels are in contact, creating a joint or seal between the panels. The slope is preferably such that, when viewed from the downwardly directed tongue, the inclined surface extends outward, and when viewed from the upwardly directed side surface, the inclined surface extends inward. The angle of inclination makes it such that the downwardly directed tongue thus has a projecting portion and the upwardly directed side surface has a recessed portion, which in the engaged state are in contact and thus provide a vertical locking effect. The slope also creates a small labyrinth that improves the waterproof properties of the joint.

A downwardly directed tongue adjacent to, typically immediately adjacent to or immediately below, the inclined contact surface comprises an outer surface. This outer surface may, for example, be the outermost surface of the downward tongue or the surface of the outer tongue furthest from the downward side surface. Likewise, an upwardly directed lateral surface adjacent the inclined contact surface, typically immediately adjacent or immediately below it, comprises an inner surface. There is space between the inner surface and the outer surface. This space is intended to prevent any force acting on or through the panels from causing the panels to be pressed together anywhere other than at the top contact surfaces and/or inclined contact surfaces. If the inner and outer surfaces were in contact, they could interfere with the contact of the upper contact surfaces, which would adversely affect the waterproof properties of the joint. On the top, on the top pin

- 3 045402 surfaces and inclined contact surfaces, the goal is to create a connection between the panels, while underneath these contact surfaces the goal is to avoid such a connection.

The upper contact surfaces may be at least partially vertical and define an internal vertical plane, wherein the inclined contact surface of the downward-facing tongue extends beyond the internal vertical plane, preferably by a maximum of 1 mm in the horizontal direction, and wherein the inclined contact surface of the upward-facing side surface lies inward compared to the internal vertical plane. Such a configuration is such that the downwardly directed tongue locally protrudes from the inner vertical plane and the upwardly directed side surface is locally recessed, wherein in the connected state the inclined contact surfaces can engage each other to create a vertical locking effect. By limiting the horizontal extent of the protrusion, the downwardly directed tab can still be connected using a downward movement or a vertical movement while providing a vertical locking effect. Thus, a portion of the downward tongue may extend beyond the inner vertical plane, which portion may be extended by a larger vertical portion than the horizontal portion, preferably the vertical portion being at least 3 times larger than the horizontal portion. This provides a relatively small horizontal portion so that the panels can still be joined in a vertical or downward motion.

Thus, a portion of the downwardly directed tongue may extend beyond the inner vertical plane, which portion may be substantially trapezoidal or wedge-shaped. This shape allows the part, when subjected to any locking, connecting or other force in the plane of the panels, to wedge into the space provided in the upward lateral surface, and also provides a strong part capable of withstanding the forces to create a tight connection between the panels. This, in turn, improves the waterproof properties of the connection between the panels.

The inclined contact surfaces can either be located on the outer side and/or adjacent to the inner vertical plane, and preferably are located entirely on the outer side of the inner vertical plane or are located entirely on one side of the inner vertical plane. This provides a relatively simple design that provides a tight connection between the two panels. Preferably, the upper contact surfaces, which define a vertical plane, directly transition into inclined contact surfaces. In this configuration, the connection of the contact surfaces continues from the top contact surfaces to the inclined contact surfaces, increasing the continuous surface, thereby improving the connection between panels and the waterproof properties of the connection.

In the connected state, the bottom of the downwardly directed tongue may contact the upper side of the upwardly directed groove on the groove contact surface, and there is a gap between the first and second connecting portions extending from the inclined contact surfaces to the groove contact surface. This gap can be used to collect, for example, dust or chips from the panels that may form when connecting two panels. In addition, such clearance is intended to prevent any force acting on or through the panels from causing the panels to be pressed together anywhere other than at the top contact surfaces and/or inclined contact surfaces. The contact surface of the groove is preferably substantially horizontal and allows forces acting on the panel and in particular on the joint between two panels, typically in a downward direction when the panel is stepped on, to be transmitted to the subfloor or surface below the panels. Preferably, the upward groove and the downward tongue are shaped such that the gap between the contact surface of the groove and the outer surface of the bottom of the downward tongue spans the width of the gap, wherein the width of the gap extends at least one-quarter of the width of the groove, more preferably along by at least a third and even more preferably by more than half the width of the groove. Said groove width is determined by the smallest horizontal width between the outer surface of the upwardly directed tongue and the upwardly directed side surface.

The upper surface of the upwardly directed tongue and the upper surface of the downwardly directed groove may, in the connected state, be spaced apart such that there is a gap between the two surfaces. Again, this clearance is intended to prevent any force applied to or by the panels from causing the panels to be pressed together anywhere other than at the top contact surfaces and/or inclined contact surfaces. The upward movement of an upwardly directed tongue can, for example, result in a horizontal force that closes or compresses the joint between two panels, in particular in so-called closed-groove lock joints. To enable this upward movement, a gap is provided between the upwardly directed tongue and the downwardly directed groove.

The upper surface of the downward groove may, for example, be formed by the lower surface of a transition portion connecting the downward tongue to the rest of the panel.

The upper contact surface and the inclined contact surface of the upwardly directed side surface may mutually constitute a first angle, and the upper contact surface and the inclined contact surface of the downwardly directed tongue may mutually constitute a second angle, wherein the first and second angles are within a difference of 20 degrees. For example, the inclined contact surface of the upward-facing side surface may mutually constitute a first angle of 120 degrees, and the upper contact surface and the inclined contact surface of the downward-facing tongue may mutually constitute a second angle of 125 degrees. The difference between the two angles is 5 degrees, which is within 20 degrees since it is less than 20 degrees.

By creating a difference between the angles, a configuration can be achieved in which a wedging action can be achieved to increase the locking forces and waterproof properties in the joint. Pressing or wedging the fixing elements against each other can result in increased fixing forces or joints in the panels.

The outer side of the upwardly directed tongue may comprise a first locking element, for example in the form of an outer convexity, and the downwardly directed side surface may be provided with a second locking element, for example in the form of a recess, in which at least part of the first and at least part of the second the fixing element are in contact in the connected state of the panels and form the surface of the fixing element. Thus, the two locking elements can cooperate to provide locking, in particular locking in a vertical direction or perpendicular to the (main) plane of the panels. The first and second locking elements are preferably integral with the panel and may, for example, be milled into the panel material. The use of cooperating locking elements prevents the two panels from substantially vertically moving relative to each other. Either or both of the first locking element and the second locking element are preferably substantially rigidly connected, respectively, to the rest of the panel, so that a relatively secure and strong fixation can be realized since relatively weak elastic locking parts are not used, in which, in addition, relatively quickly Material fatigue may occur. The first locking element may form an integral part of the upwardly directed tongue, wherein the first locking element can be formed, for example, due to a protruding (outwardly convex) or recessed (inwardly convex) deformation of an edge of the upwardly directed tongue.

The first locking element may be an outer bulge, wherein the outer side of the outer bulge comprises an upper portion and an adjacent lower portion, the lower portion comprising an inclined, preferably flat, locking surface, and the upper portion including a preferably curved guide surface. The first locking element on the outer side of the upward tab abuts the downward side surface of the other panel during connection because it is the projecting portion of the panel and is typically the outermost portion of the panel on one side and requires a force to be overcome during connections to press one panel into another. By providing a (curved) guide surface on the top, an additional or other panel is guided downward so that the connection can occur gradually and large material deformations and/or stress peaks can be prevented. In this way, the lower part can be inclined and form part of the bulge, which from the outermost part of the bulge returns to the upward-pointing tongue. This inclined surface also performs a guiding function, guiding the panels to their final stage. The inclination of the locking surface further allows the potential upward force or movement of the panels to result in a vertical and horizontal force component. The horizontal component can be used to hold panels together by pressing the panels against each other to improve the joint and waterproof properties of the joint between panels. The second locking element may be a recess comprising a top portion and an adjacent bottom portion, the bottom portion comprising an inclined, preferably flat, locking surface for engagement with the first locking element. In addition, inclined surfaces have the advantage, for example, over rounded surfaces, that they are relatively easy to manufacture or mill, and it is relatively easy to provide a relatively large contact surface between them to distribute the locking forces in the connected panels. Preferably, in the connected state of adjacent panels, the outer convex and the recess interact with each other exclusively by means of inclined locking surfaces. In this way, the functionality and effect of the inclined locking surfaces can be improved. Preferably, in the connected state of adjacent panels, only a portion of the inclined locking surface of the lower part of the outer convex interacts only with 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 outer convex is longer, preferably at least 1.5 times longer, than the inclined locking surface of the lower part of the recess.

Preferably the upper outer side is substantially vertical and defines

- 5 045402 an outer vertical plane, wherein at least part of the first fixing element protrudes from the outer vertical plane, at least partially, preferably by a maximum of 2 mm, more preferably by a maximum of 1 mm, in the horizontal direction. The outer vertical plane generally divides the upwardly directed tongue into an inner section directed towards the upwardly facing side surface and an outer section which contains the first locking element, the maximum width of the inner section being preferably at least 8 times, preferably at least 10 times, the maximum width of the outer section.

The first locking element and the second locking element are preferably located at a level below the level of the inclined contact surfaces of the downwardly directed tongue and the upwardly directed side surface. This generally reduces the degree of deformation of the connecting parts during the joining process, which helps to increase the service life and reliability of the connecting parts. Preferably, the level of the inclined contact surfaces of the downward-facing tongue and the upward-facing side surface is above the level of the highest point of the upward-facing tongue. This is generally beneficial in order to create a waterproof barrier as close to the top surface of the panels as possible.

Preferably, at least a portion of the upper portion of the outer convexity located on the outer side of the upwardly directed tongue is located at a higher level than the level defined by the lowest point of the upwardly directed groove, and preferably at least a portion of the upper portion of the recess located on the downward side surface is located at a higher level than the level defined by the lowest point of the upward groove. The inclined contact surfaces of said convexity and recess are preferably located below the lowest point of the upwardly directed groove. This generally facilitates the joining process, but can also be advantageous for the separation of panels connected to each other by means of a downward inclined movement of the panels relative to each other.

The top can extend over a larger vertical section than the bottom to gradually guide the panels into place. The top portion generally does not provide a vertical locking effect, so its horizontal portions are of less importance compared to the lower portion, which typically provides a vertical locking effect. The parts of the first and second locking elements that are in contact in the connected state of the panels are usually formed by the inclined locking surfaces of the locking elements, that is, the lower parts. In the connected state of the panels, the tops of the first and second locking elements can be at least partially spaced apart. This distance allows the upward-facing tongue to move upward without being obstructed by the downward-facing side surface, which upward movement in turn can be transferred and translated into a closing horizontal movement to improve the connection or fixation of the panels, pressing the panels together.

The outer side of the upwardly directed tongue may comprise an upper outer portion and a lower outer portion, with a first locking element located between the upper and lower outer portions, with the lower outer portion located closer to the inner side of the upwardly directed tongue compared to the upper outer portion. The upper outer side may be substantially vertical and defines an outer vertical plane, with the first locking element protruding from the outer vertical plane at least partially, 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 another vertical plane parallel but offset, with the vertical plane of the lower outer portion being located closer to the upwardly oriented side surface. This difference creates a relatively large panel spacing at the intersection between the angled locking surface of the upward tongue and the lower outer portion, allowing for greater upward angle or rotational movement of the upward tongue and thus potentially greater closure or tension force of the locking elements for improved connections and waterproofing properties of panels. For the purpose of providing greater tensile force between the panels to create a watertight connection between them, it may also be useful when the inclined contact surface of the downward tongue, the inclined contact surface of the upward side surface, the inclined fixing surface of the upward groove and the inclined fixing surface of the downward side surface pass essentially in parallel.

The lower outer side may be substantially vertical, and the inclined locking surface or the lower part and the lower outer part form an angle of 100 to 175 degrees, in particular 100 to 150 degrees, more particularly 110 to 135 degrees. This angle provides the best combination of fixing and guiding properties. The angle formed between the upper contact surfaces and the inclined contact surfaces and the angle formed between the lower outer part and the inclined locking surface or the lower part may differ within 20 degrees and should preferably be the same. This allows for relatively simple manufacturing where the same or similar tool can be used to mill both elements from the panel.

The outermost portion of the first locking element may be located at a horizontal level that is lower than the upwardly directed groove. Thus, as the panels move downwards during joining, the widest or outermost part of the first locking element is encountered relatively late, making it easier to join the two panels.

The panels according to the invention are, for example, at least partially made of magnesium oxide or based on magnesium oxide. A panel according to the invention may comprise: a core having a top and a bottom side, a decorative top structure (or top section) attached directly or indirectly to said top side of the core, said core comprising: at least one composite layer comprising: at least one composition based on magnesium oxide (magnesia) and/or magnesium hydroxide, in particular magnesia cement. Particles, in particular cellulose and/or silicone based particles, can be dispersed in said magnesia cement. Optionally, one or more reinforcing layers, such as fiberglass layers, may be embedded in said composite layer. The core composition may also contain magnesium chloride, resulting in magnesium oxychloride (MOC) cement, and/or magnesium sulfate, resulting in magnesium oxysulfate (MOS) cement.

It has been found that the use of a composition based on magnesium oxide and/or magnesium hydroxide and, in particular, magnesium cement including MOS and MOC, significantly improves the flammability of the decorative panel itself. In addition, the relatively fire-resistant panel also has significantly improved dimensional stability under temperature fluctuations during normal use. Magnesia cement is a cement based on magnesia (magnesium oxide), in which the cement is the product of a chemical reaction in which magnesium oxide is one of the reactants. In magnesia cement, magnesia may still be present and/or has undergone a chemical reaction to form another chemical bond, as will be explained in more detail below. Below are the additional benefits of magnesium cement over other types of cement. The first additional benefit is that magnesia cement can be produced in a relatively energy-efficient and therefore cost-effective manner. In addition, magnesia cement has relatively high compressive and tensile strength.

Another advantage of magnesia cement is that this cement has a natural affinity for - usually inexpensive - cellulosic materials such as plant fiber wood powder (wood dust) and/or wood shavings; this not only improves the adhesion of magnesium cement, but also leads to reduced mass and greater sound insulation (damping). Magnesium oxide combines with cellulose and optionally clay to form magnesium cements, which are permeable to water vapor; this cement does not deteriorate (rot) because this cement effectively displaces moisture. In addition, magnesia cement is a relatively good insulating material, both thermally and electrically, making the panel particularly suitable for flooring in radar stations and hospital operating rooms. An additional advantage of magnesia cement is that it has a relatively low pH level compared to other types of cement, which together allows for greater durability of glass fibers dispersed in the cement matrix and/or (as glass fibers) as a reinforcing layer, and, In addition, it allows the use of other types of fibers in a durable manner. At the same time, an additional advantage of the decorative panel is that it is suitable for both interior and exterior use.

As already mentioned, magnesium cement is based on magnesium oxide and/or magnesium hydroxide. Magnesia cement itself may not contain magnesium oxide, depending on the additional reagents used to prepare the magnesia cement. In this case, for example, it is quite possible that magnesia as a reactant is converted into magnesium hydroxide during the production of magnesia cement.

Therefore, magnesium cement as such may contain magnesium hydroxide. Typically, magnesia cement contains water, in particular hydrated water. Water is commonly used as a binder to create a strong and cohesive cement matrix.

The magnesia-based composition, in particular magnesia cement, may contain magnesium chloride (MgCl ₂ ). Typically, when magnesia (MgO) is mixed with magnesium chloride in an aqueous solution, magnesium cement containing magnesium oxychloride (MOC) is formed. The binding phases are Mg(OH) ₂ , 5Mg(OH) ₂ .MgCl ₂ .8H ₂ O (form 5), 3Mg(OH) ₂ .MgCl ₂ .8H ₂ O (form 3), and Mg ₂ (OH)ClCO _r 3H ₂ O. Form 5 is the preferred phase since this phase has excellent mechanical properties. Compared to other types of cement such as Portland cement, MOC has superior properties. MOC does not require wet curing, has high fire resistance, low thermal conductivity, good abrasion resistance. MOC cement can be used with various aggregates (additives) and fibers with good adhesion. It can also receive various types of surface treatments. MOC develops high compressive strength within 48 hours (e.g.

- 7 045402

8000-10000 psi). The increase in compressive strength occurs at an early stage of curing - the 48-hour strength will be at least 80% of the ultimate strength.

The MOC compressive strength is preferably in the range of 40 to 100 N/mm ² . The flexural strength is preferably 10-17 N/mm2. The surface hardness of MOC is preferably 50-250 N/mm ² . The elastic modulus is preferably 1-3 10 ⁴ N/mm ² . The flexural strength of MOC is relatively low, but it can be significantly improved by the addition of 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. The MOC used in the panel of the invention may be enriched with one or more of these fiber types. MOC does not shrink, is resistant to abrasion and wear, impact, dents and scratches. MOC is resistant to heat and freeze-thaw cycles and does not require air entrainment for increased durability. In addition, MOC has excellent thermal conductivity, low electrical conductivity and excellent adhesion to various substrates and additives, and also has acceptable flame retardant properties. MOC is less preferred if the panel is exposed to relatively extreme weather conditions (temperature and humidity) that affect both the adhesion properties and the formation of the magnesium oxychloride phase. Over time, atmospheric carbon dioxide will react with magnesium oxychloride to form a surface layer of Mg ₂ (OH)ClCO ₃ .3H ₂ O. This layer serves to slow the leaching process. Ultimately, additional leaching leads to the formation of hydromagnesite 4MgO.3CO ₃ . 4H ₂ O, which is insoluble and allows the cement to maintain structural integrity.

The magnesium-based composition and, in particular, magnesium cement can be based on magnesium sulfate, in particular the epsomite sulfate mineral heptahydrate (MgSO ₄ -7H ₂ O). This last salt is also known as Epsom salt. In aqueous solution, MgO reacts with MgSO4, resulting in the formation of magnesium oxysulfate cement (MOS), which has very good cementitious properties. In MOS, the most commonly occurring chemical phase is 5Mg(OH) _2.MgSO4.8H2O . Although MOS is not as strong as MOC, MOS is better suited for flame retardant _applications because MOS begins to decompose at _temperatures more than twice that MOC temperature, which provides longer fire protection. In addition, their decomposition products at elevated temperatures are less harmful (sulfur dioxide) than oxychloride products (hydrochloric acid), and are also less aggressive. Additionally, weather conditions (humidity, temperature and wind) during application are not as critical for MOS as they are for MOC. The mechanical strength of MOC cement depends mainly on the type and relative content of crystalline phases in the cement. Four major magnesium salts that may contribute to the mechanical strength of MOS cement were found to exist in the ternary system MgO-MgSO ₄ -H ₂ O at various temperatures ranging from 30 to 120 degrees Celsius 5Mg(OH) ₂ -MgSO ₄ -3H ₂ O (phase 513), 3Mg(OH) ₂ -MgSO ₄ -8H ₂ O (phase 318), Mg(OH) ₂ -2MgSO ₄ -3H ₂ O (phase 123), and Mg(OH) ₂ -MgSO ₄ -5H ₂ O (phase 115). Typically, phase 513 and phase 318 could only be obtained by curing the cement under saturated steam conditions, with the molar ratio of MgO to MgSO4 fixed at (approximately) 5:1. The 318 phase has been found to contribute significantly to mechanical strength and is stable at room temperature and is therefore preferable to be present in the applied MOS. This also applies to the phase 513. Said phase 513 typically has a (micro)structure including a needle-like structure. This can be verified using SEM analysis. Magnesium oxysulfate needles (5Mg(OH) ₂ -MgSO ₄ -3H ₂ O) can be almost uniform and usually have a length of 10-15 µm and a diameter of 0.4-1.0 µm. When referring to a needle-like structure, a scaly structure and/or a thread-like structure may also be implied. In practice, it is not possible to obtain MOS containing more than 50% phase 513 or 318, but by adjusting the composition of the crystalline phase, the mechanical strength of MOS can be increased.

Preferably the magnesia cement contains at least 10%, preferably at least 20% and more preferably at least 30% 5Mg(OH) ₂ -MgSO ₄ -3H ₂ O (513 phase). This preferred embodiment provides magnesia cement having sufficient mechanical strength for use in the core layer of a floor panel.

The crystalline phase of MOS can be controlled by modifying MOS using an organic acid, preferably citric acid and/or phosphoric acid and/or phosphates. This modification can produce new MOS phases, which can be expressed as 5Mg(OH) _2.MgSO4.5H2O (phase ₅₁₅ ) and Mg(OH) _{2- MgSO4-7H2O (} phase 517). Phase 515 can be prepared by modifying MOS using citric acid. Phase 517 can be prepared by modifying MOS using phosphoric acid and/or phosphates (H ₃ PO ₄ , KH ₂ PO ₄ , K ₃ PO ₄ and K ₂ HPO ₄ ). These phase 515 and phase 517 can be determined by chemical elemental analysis, with SEM analysis proving that the microstructure of both phase 515 and phase 517 is a needle crystal, insoluble in water. In particular, the compressive strength and water resistance of MOS can be improved by adding citric acid. Therefore, it is preferable that MOS, if used in

- 8 045402 panels according to the invention, contained:

5Mg (OH) 2-MgSO ₄ -5H ₂ O (phase 515) and/or Mg(OH) ₂ -MgSO ₄ -7H ₂ O (phase 517). As stated above, the addition of phosphoric acid and phosphates can increase the setting time and improve the compressive strength and water resistance of MOS cement by changing the MgO hydration process and phase composition. In this case, phosphoric acid or phosphates are ionized in solution to form H ₂ PO ₄ ^- , HPO 4 ^{2 -} , and/or PO4 ^{3 -} , where these anions are adsorbed onto [Mg(OH)(H2O) ^x ] ⁺ , inhibiting the formation of Mg( OH)2 and further promotes the formation of a new magnesium subsulfate phase, which leads to a compact structure, high mechanical strength and good water resistance of MOS cement. The improvement caused by the addition of phosphoric acid or phosphates to MOS cement follows the order H ₃ PO ₄ = KH2PO+ >> K ₂ HPO ₄ >> K ₃ PO ₄ . MOS has better volumetric stability, less shrinkage, better binding properties and less corrosivity under a much wider range of weather conditions than MOC and may therefore be preferred over MOS. The density of MOS typically ranges from 350 to 650 kg/m ³ . The flexural strength is preferably 1-7 N/mm ² .

The magnesium cement composition preferably contains one or more silicone-based additives. A variety of silicone-based additives may be used, including, but not limited to, silicone oils, neutral-cure silicones, silanols, silanol liquids, silicone (micro)spheres or silicone particles, and mixtures and derivatives thereof. Silicone oils include liquid polymerized siloxanes with organic side chains, including, but not limited to, poly(methyl)siloxane and its derivatives. Neutral-cure silicones include silicones that release alcohol or other volatile organic compounds (VOCs) when cured. Other silicone-based additives and/or siloxanes (e.g., siloxane polymers) may also be used, including, but not limited to, hydroxyl (or hydroxy) terminated siloxanes and/or other reactive siloxanes, acrylic siloxanes, urethane siloxanes, epoxy siloxanes and mixtures and derivatives thereof. As described in detail below, one or more cross-linking agents (eg, silicone-based cross-linking agents) can also be used. The viscosity of one or more silicone-based additives (e.g., silicone oil, neutral-cure silicone, silanol fluid, siloxane polymers, etc.) may be around 100 cSt (at 25°C), which is called low-viscosity. In alternative embodiments, the viscosity of one or more silicone-based additives (e.g., silicone oil, neutral cure silicone, silanol fluid, siloxane polymers, etc.) is from about 20 cSt (25°C) to about 2000 cSt (25°C). C). In other embodiments, the viscosity of one or more silicone-based additives (e.g., silicone oil, neutral cure silicone, silanol fluid, siloxane polymers, etc.) is from about 100 cSt (25°C) to about 1250 cSt (25°C). C). In other embodiments, the viscosity of one or more silicone-based additives (e.g., silicone oil, neutral cure silicone, silanol fluid, siloxane polymers, etc.) is from about 250 cSt (25°C) to 1000 cSt (25°C ).

In other embodiments, the viscosity of one or more silicone-based additives (e.g., silicone oil, neutral cure silicone, silanol fluid, siloxane polymers, etc.) is from about 400 cSt (25°C) to 800 cSt (25°C ). And in specific embodiments, the viscosity of one or more silicone-based additives (e.g., silicone oil, neutral cure silicone, silanol fluid, siloxane polymers, etc.) is from about 800 cSt (25°C) to about 1250 cSt (25°C). °C). One or more silicone-based additives having a higher and/or lower viscosity may also be used. For example, in additional embodiments, the viscosity of one or more silicone-based additives (e.g., silicone oil, neutral cure silicone, silanol fluid, siloxane polymers, etc.) is from about 20 cSt (25°C) to about 200,000 (25°C). °C) cSt, from about 1000 cSt (25°C) to about 100,000 cSt (25°C) or from about 80,000 cSt (25°C) to about 150,000 cSt (25°C).

In other embodiments, the viscosity of one or more silicone-based additives (e.g., silicone oil, neutral cure silicone, silanol fluid, siloxane polymers, etc.) is from about 1,000 cSt (25°C) to about 20,000 cSt (25°C). C), from about 1000 cSt (25°C) to about 10000 cSt (25°C), from about 1000 cSt (25°C) to about 2000 cSt (25°C) or from about 10000 cSt (25°C) up to about 20,000 cSt (25°C). In still other embodiments, the viscosity of one or more silicone-based additives (e.g., silicone oil, neutral cure silicone, silanol fluid, siloxane polymers, etc.) is from about 1000 cSt (25°C) to about 80,000 (25°C). C) cSt, from about 50,000 cSt (25°C) to about 100,000 cSt (25°C) or from about 80,000 cSt (25°C) to about 200,000 cSt (25°C). And in still further embodiments, the viscosity of the one or more silicone-based additives (e.g., silicone oil, neutral cure silicone, silanol fluid, siloxane polymers, etc.) is from about 20 cSt (25°C) to about 100 cSt ( 25°C). Other viscosities can also be used as desired.

In a preferred embodiment, the magnesium cement composition, in particular a magnesium oxychloride cement composition, contains one type of silicone-based additive. IN

- 9 045402 In other embodiments, a mixture of two or more types of silicone-based additives is used. For example, in some embodiments, the magnesium oxychloride cementitious composition may include a mixture of one or more silicone oils and neutral curing silicones; in particular embodiments, the ratio of silicone oil to neutral curing silicone may be from about 1:5 to about 5:1 by weight. In other embodiments, the ratio of silicone oil to neutral cure silicone may be from about 1:4 to about 4:1 by weight. In other embodiments, the ratio of silicone oil to neutral cure silicone may be from about 1:3 to about 3:1 by weight. In still other embodiments, the ratio of silicone oil to neutral cure silicone may be from about 1:2 to about 2:1 by weight. In additional embodiments, the ratio of silicone oil to neutral cure silicone may be about 1:1 by weight.

It can be imagined that magnesia cement uses one or more cross-linking agents. In some embodiments, the crosslinkers are silicone-based crosslinkers. Examples of crosslinking agents include, but are not limited to, methylrimethoxysilane, methyltriethoxysilane, methyltris(methylethylketoxyimino)silane, and mixtures and derivatives thereof. Other crosslinkers (including other silicone-based crosslinkers) may also be used. In some embodiments, the magnesium oxychloride cement composition contains one or more silicone-based additives (eg, one or more silanols and/or silanol fluids) and one or more cross-linking agents. The ratio of one or more silicone-based additives (e.g., silanols and/or silanol fluids) to crosslinking agent may be from about 1:20 to about 20:1 by weight, from about 1:10 to about 10:1 by weight, or from about 1:1 to about 10:1 by weight.

Magnesium (oxychloride) cement compositions containing one or more silicone-based additives may exhibit reduced sensitivity to water compared to traditional magnesium (oxychloride) cement compositions. Additionally, in some embodiments, magnesium (oxychloride) cementitious compositions including one or more silicone-based additives may exhibit little or no sensitivity to water.

Magnesium (oxychloride) based cement compositions containing one or more silicone based additives may additionally exhibit hydrophobic and water resistant properties.

Additionally, magnesium (oxychloride) cementitious compositions containing one or more silicone-based additives may exhibit improved curing characteristics. For example, magnesium (oxychloride) based cement _compositions cure to form various reaction products, including the crystal _structures 3Mg(OH) _2.MgCl2.8H2O ( _phase 3) and 5Mg(OH) _{2.MgCl2.8H2O (} phase 5). In some situations, higher percentages of the 5Mg(OH) ₂ .MgCl ₂ .8H ₂ O (phase 5) crystal structure are preferred. In such situations, adding one or more silicone-based additives to magnesium oxychloride cement compositions can stabilize the curing process, _which can increase the percentage _yield of 5Mg(OH) _2.MgCl2.8H2O (phase 5) crystalline structures. For example, in some _embodiments , magnesium _oxychloride compositions including one or more silicone-based additives can be cured to form greater than 80% 5Mg(OH) _2.MgCl2.8H2O crystal structures (phase 5). In other _{embodiments , magnesium oxychloride compositions including one or more silicone-based additives can be cured to form greater than 85% 5Mg(OH)2.MgCl2.8H2O crystal} structures (phase 5). In still other embodiments, magnesium _oxychloride compositions including one or more silicone-based additives can be cured to form greater than 90% 5Mg(OH) _2.MgCl2.8H2O crystal structures ( _phase 5). In yet other _embodiments , magnesium oxychloride compositions including one or more silicone-based additives can be cured to form greater than 95% 5Mg(OH) _2.MgCl2.8H2O crystal structures ( _phase 5). In still other embodiments _, magnesium oxychloride compositions including one or more silicone-based additives can be cured to form greater than 98% 5Mg(OH) _2.MgCl2.8H2O crystal structures ( _phase 5). In yet other embodiments, magnesium _{oxychloride compositions including one or more silicone-based additives can be cured to form about 100% 5Mg(OH)2.MgCl2.8H2O crystal} structures ₍ phase 5).

In addition, magnesium (oxychloride) based cementitious compositions containing one or more silicone-based additives may also exhibit enhanced strength and adhesion characteristics. If desired, magnesium (oxychloride) cement compositions including one or more silicone-based additives can also be used to produce magnesium (oxychloride) cement or concrete structures that are relatively thin. For example, magnesium (oxychloride) based cement compositions containing one or more silicone based additives can be used to make cement or concrete structures or layers having a thickness of less than 8 mm, preferably less than 6 mm.

- 10 045402

To effect the connection between the connecting part, it may be desirable and/or even necessary to temporarily deform the connecting part(s), whereby it is advantageous to mix magnesium oxide and/or magnesium hydroxide and/or magnesium chloride and/or magnesium sulfate with one or several silicone-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 flex or flex without cracking or breaking.

Magnesium (oxychloride) cementitious compositions containing one or more silicone-based additives may further contain one or more additional additives. Additional additives may be used to improve specific characteristics of the composition. For example, in some embodiments, additional additives may be used to impart the appearance of stone (eg, granite, marble, sandstone, etc.) to structures formed using the disclosed magnesium oxychloride cement compositions. 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 cementitious compositions can also form UV stable structures such that the color and/or appearance is not subject to significant fading due to UV radiation over time. Other additives may also be included in the composition, including, but not limited to, plasticizers (eg, polycarboxylic acid plasticizers, polycarboxylate ester plasticizers, etc.), surfactants, water, and mixtures and combinations thereof. As stated above, the magnesium oxychloride cement composition, if used, may contain magnesium oxide (MgO), an aqueous solution of magnesium chloride (MgCl ₂ (aq)) and one or more silicone-based additives. Instead of aqueous magnesium chloride (MgCl2) solution, magnesium chloride (MgCl2) powder can also be used. For example, magnesium chloride (MgCl ₂ ) powder may be used in combination with an amount of water that would be equivalent or otherwise similar to the addition of aqueous magnesium chloride (MgCl ₂ (aq)).

In some embodiments, the ratio of magnesium oxide (MgO) to aqueous magnesium chloride (MgCl ₂ (aq)), if used, in the magnesium oxychloride cement composition may vary. In some such embodiments, the ratio of magnesium oxide (MgO) to aqueous magnesium chloride (MgCl ₂ (aq)) is from about 0.3:1 to about 1.2:1 by weight. In other embodiments, the ratio of magnesium oxide (MgO) to aqueous magnesium chloride (MgCl2(aq)) is from about 0.4:1 to about 1.2:1 by weight. In still other embodiments, the ratio of magnesium oxide (MgO) to aqueous magnesium chloride (MgCl ₂ (aq)) is from about 0.5:1 to about 1.2:1 by weight.

Aqueous magnesium chloride (MgCl2 (aq)) can be described as (or derived from) a brine solution of magnesium chloride. 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, and so on.

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

It is also preferred and even advantageous to include at least one oil, such as linseed oil or silicone oil, in the core layer. This gives the magnesium-based core layer and/or thermoplastic-based middle layer greater flexibility and reduces the risk of breakage. Instead of or in addition to oil, it is also conceivable to include one or more water-soluble polymers or polycondensed resins, such as polycarboxylic acid, in the core layer. This results in the advantage that the panel does not shrink during drying/curing/setting, which prevents cracking, and in addition makes the base layer more hydrophobic after drying/curing/setting, which prevents the penetration of water (moisture) when subsequent storage and use.

The core layer can be imagined to contain polycaprolactone (PCL). This biodegradable polymer is particularly preferred since it has been found to melt due to the exothermic reaction of the reaction mixture. It has a melting point of about 60°C. PCL can be low density or high density. The latter option is particularly preferred as it provides a stronger core layer. Instead of or in addition to other polymers, other polymers may be used, preferably a polymer selected from the group consisting of: other poly(lactic-glycolic acid) (PLGA), poly(lactic acid) (PLA), poly(glycolic acid) (PGA) ), polyhydroxyalkanoate (PHA) family, polyethylene glycol (PEG),

- 11 045402 polypropylene glycol (PPG), polyesteramide (PEA), poly(lactic acid-co-caprolactone), poly(lactide-co-trimethylene carbonate), poly(sebacic acid-coricinoleic acid) and a combination thereof.

Alternatively, the panel, in particular the core layer, can be at least partially made of PVC, PET, PP, PS or (thermoplastic) polyurethane (PUR). PS can be in the form of extended PS (EPS) to further reduce panel density, resulting in cost savings and easier handling of the panels. Preferably, at least a portion of the polymer used may be formed from recycled thermoplastic, such as recycled PVC or recycled PUR. Recycled PUR can be made from recyclable polymers, such as recyclable PET. PET can be processed chemically using glycolysis or depolymerization of PET into monomers or oligomers and then eventually into polyurethane polyols. It is also possible for rubber and/or elastomeric particles to be dispersed within at least one composite layer to improve flexibility and/or impact resistance to at least some extent. It is possible that a mixture of virgin and recycled thermoplastic materials is used to make at least part of the core. Preferably, in this mixture, the virgin thermoplastic material and the recycled thermoplastic material are substantially the same. For example, such a mixture may be entirely PVC based or entirely PUR based. The core may be solid or foam, or both in case the core consists of multiple parts/layers.

This may be advantageous if the core layer contains porous granules, in particular porous ceramic granules. Preferably, the granules have a plurality of micropores with an average diameter of from 1 micron to 10 microns, preferably from 4 to 5 microns. That is, the individual granules preferably have micropores. Preferably the micropores are interconnected. Preferably they are not limited to the surface of the granules, but are located essentially throughout the entire cross-section of the granules. Preferably, the granule size is from 200 microns to 900 microns, preferably from 250 microns to 850 microns, especially from 250 to 500 microns or from 500 to 850 microns. Preferably, at least two different granule sizes are used, most preferably two. Preferably, small and/or large granules are used. Small granules can range in size from 250 to 500 microns. Preferably, the coarse granules have a diameter between 500 microns and 850 microns. Each granule may be substantially the same size or two or more predetermined sizes. Alternatively, two or more different size ranges may be used, with a plurality of different particle sizes within each range. Preferably, two different sizes or ranges of sizes are used. Preferably, each granule contains a plurality of microparticles, substantially each microparticle being partially fused with one or more adjacent microparticles to form a lattice defining the micropores. Each microparticle preferably has an average size of from 1 micron to 10 microns, with an average of 4 to 5 microns. Preferably, the average micropore size is from 2 to 8 microns, most preferably from 4 to 6 microns. Micropores may have irregular shapes. Accordingly, the size of the micropores and even the medium-sized pores mentioned below is determined by adding the widest pore diameter to the narrowest pore diameter and dividing by 2. Preferably, the ceramic material is distributed evenly across the cross-section of the core layer, i.e., without substantially clumping the ceramic material . Preferably, the microparticles have an average size of at least 2 microns or 4 microns and/or less than 10 microns or less than 6 microns, most preferably from 5 to 6 microns. This particle size range has been found to provide controlled micropore formation.

The granules may also contain a plurality of substantially spherical medium sized pores having an average diameter of from 10 to 100 microns. They significantly increase the overall porosity of the ceramic material without compromising the mechanical strength of the materials. The medium-sized pores are preferably interconnected through a plurality of micropores. That is, medium-sized pores can be in hydraulic communication with each other through micropores. The average porosity of the ceramic material itself is preferably at least 50%, more preferably greater than 60%, most preferably 70 to 75% of the average porosity. The ceramic material used to make the granules can be any (non-toxic) ceramic known in the art, such as calcium phosphate and glass ceramic. The ceramic may be silicate, although preferably it is calcium phosphate, especially α- or βtricalcium phosphate or hydroxyapatite, or mixtures thereof. Most preferably, the mixture is hydroxyapatite and β-tricalcium phosphate, especially more than 50% by weight β-tricalcium, most preferably 85% β-tricalcium phosphate and 15% hydroxyapatite. Most preferably the material is 100% hydroxyapatite. Preferably, the cement composition or dry premix contains from 15 to 30% by weight of granules based on the total dry weight of the composition or premix.

Porous particles can lead to a lower average density of the core layer and therefore a reduction in mass, which is favorable from an economic and handling point of view. In addition, the presence of porous particles in the core layer usually results in at least

- 12 045402 to some extent to increased porosity of the porous top surface and bottom surface of the core layer, which is favorable for attaching an additional layer to the top surface and/or bottom surface of the core layer, such as, for example, a primer layer, an (initially liquid) adhesive layer or another decorative or functional layer. Often these layers are initially applied in a liquid state, with the pores allowing the liquid substance to be absorbed (permeate) into the pores, which increases the contact surface area between the layers and therefore improves the bond strength between said layers.

The panels may have a multi-layer structure comprising, for example, a central core (or core layer) and at least one decorative top section directly or indirectly attached to or integrated with said core layer, the top section forming the top surface of the panel. The top section preferably comprises at least one decorative layer attached directly or indirectly to the top surface of the core layer. The decorative layer may be a printed layer and/or may be covered with at least one protective (top) layer covering said decorative layer. The protective layer is also part of the decorative top section. The presence of a printed layer and/or protective layer can prevent damage to the tile due to scratches and/or environmental factors such as UV radiation/moisture and/or wear and tear. The printed layer may be formed by a film on which a decorative print is applied, the film being attached to a backing layer and/or an intermediate layer, such as a primer layer, located between the backing layer and the decorative layer. The printing layer may also be formed by at least one layer of ink that is applied directly to the top surface of the core layer or to a primer layer applied to the backing layer. The panel may comprise at least one wear-resistant layer attached directly or indirectly to the top surface of the decorative layer. The wear layer is also part of the decorative top section. Each panel may comprise at least one varnish layer attached directly or indirectly to the top surface of the decorative layer, preferably to the top surface of the wear layer.

The underside (back side) of the core (core layer(s)) may also constitute the underside (back side) of the panel itself. However, it is possible and may even be preferable for the panel to comprise a backing layer directly or indirectly attached to said lower portion of the core. Typically, the protective layer acts as a balancing layer to stabilize the shape, in particular the flatness of the panel itself. Moreover, the underlayment usually contributes to the sound absorption properties of the panel itself. Since the underlayer is typically a closed layer, applying the underlayer to the underside of the core covers the grooves of the core at least partially, and preferably completely. In this case, the length of each core groove is preferably less than the length of said backing layer.

The underlayment layer may be provided with cut portions, wherein at least a portion of said cut portions are overlapped by at least one core groove. The at least one bedding layer is preferably at least partially made of a flexible material, preferably an elastomer. The thickness of the litter layer usually varies from about 0.1 to 2.5 mm. Non-limiting examples of materials from which the bedding layer may be at least partially composed include polyethylene, cork, polyurethane, polyvinyl chloride and ethylene vinyl acetate. Optionally, the bedding layer contains one or more additives, such as fillers (eg, chalk), dyes, resins, and/or one or more plasticizers. In a particular embodiment, the bedding layer is at least partially made from a composite of ground (or shaved) cork particles bound with resin. Instead of cork, you can use other wood-related products, such as timber. The thickness of the polyethylene underlayer is usually, for example, 2 mm or less. The bedding layer can be solid or foam. A foam underlayment can further improve sound absorption properties. A hard underlayment can improve the desired balancing effect and stability of the panel.

The inner side of the upward tongue and the inner side of the downward tongue may contact in a connected state to transfer forces between them, in particular, from the upward tongue to the downward tongue.

The inner sides of the tongues may be in contact on the contact surfaces of the tongues, and the contact surfaces of the tongues may be inclined. The inclination may be such that a portion of the inner side of the upwardly directed tongue is inclined toward the side surface such that a tangent from the contact surface of the tongue intersects with an inner vertical plane above the contact surface of the tongue. Alternatively, the slope may be such that a portion of the inner side of the tongue is inclined from the upwardly oriented side surface such that a tangent from the tongue contact surface intersects the inner vertical plane below the tongue contact surface. This represents closed groove systems and open groove systems respectively. Closed-groove systems provide improved locking but are more difficult to join, while open-groove systems are easier to join but do not provide the additional vertical locking of a closed-groove system.

The first and second connecting parts are located on opposite sides of the panel. The panel is, for example, rectangular, parallelogram and/or elongated, and the first and second connecting portions may be located on both opposite sides (ie, all four sides) of such a panel. It is also possible to provide the first and second coupling portions on only one pair of opposite sides and to provide other coupling portions such as downwardly inclined coupling portions with a sideways tongue and a sideways groove on the other pair of opposite sides.

The invention further relates to a covering, in particular a floor covering, comprising a plurality of interconnected panels according to any one of the present invention.

Preferred embodiments of the invention are presented in a non-limiting set of paragraphs below.

Items.

1. Panel (1), in particular a floor panel, comprising:

a) at least one first connecting part (2) and at least one second connecting part (3) located on opposite sides of the panel (1), wherein the first connecting part (2) of said panel and the second connecting part (3) the other panel (1) is designed to be connected by means of a downward movement;

b) wherein the first connecting part (2) contains an upwardly directed tongue (4), at least one upwardly directed side surface (5) lying at a distance from the upwardly directed tongue (4), and an upwardly directed groove (6) formed between the upwardly directed tongue (4) and the upwardly directed side surface (5), wherein the upwardly directed groove (6) is configured to receive at least part of the downwardly directed tongue (7) of the second connecting part (3) of the other panel (1), wherein the side of the upwardly directed tongue (4) facing the upwardly directed side surface is the inner side (8) of the upwardly directed tongue (4), and the side of the upwardly directed tongue (4) facing away from the upwardly directed side surface (5) is the outer side (9) of the tongue (4) directed upwards;

c) wherein the second connecting part (3) comprises a downwardly directed tongue (7), at least one downwardly directed side surface (10) lying at a distance from the downwardly directed tongue (7), and a downwardly directed groove (11) formed between the downwardly directed tongue (7) and the downwardly directed side surface (10), wherein the downwardly directed groove (11) is configured to receive at least part of the upwardly directed tongue (4) of the first connecting part (2) of the other panel (1), wherein the side of the downward tongue (7) facing the downward side surface (10) is the inner side (12) of the downward tongue (7), and the side of the downward tongue (7) facing away from the downward side surface (10) ), is the outer side (13) of the downward-facing tongue (7);

d) wherein both the outer side (13) of the downwardly directed tongue (7) and the upwardly directed side surface (5) comprise an upper contact surface (14) adjacent to or towards the upper side of the panel (1), said contact surfaces (14) extend substantially vertically, at least partially, and wherein the upper contact surface (14) of the outer side (13) of the downwardly directed tongue (7) of said panel is configured to engage the upper contact surface (14) of the upwardly directed side surface (5) an adjacent panel in the connected state of said panels (1);

e) wherein the adjacent upper contact surfaces (14) of both the downwardly directed tongue (7) and the upwardly directed side surface (5) comprise an inclined contact surface (15), wherein the inclined contact surface (15) of the downwardly directed tongue (7) said panel is configured to engage, preferably when offset, with an inclined contact surface (15) of an upwardly directed side surface (5) of an adjacent panel, in the connected state of said panels (1), each vertical portion of the upper contact surface (14) and each the adjacent inclined surface (15) mutually make an angle (α) from 100 to 175 degrees;

f) in this case, the downward directed tongue (7) adjacent to the inclined contact surface (15) contains an outer surface (16) located below the inclined contact surface (15) of the downward directed tongue (7), and at the same time adjacent to the inclined contact surface (15 ) the upwardly directed side surface (5) comprises an inner surface (17) located below the inclined contact surface (15) of the upwardly directed side surface (5), wherein the outer (16) and inner (17) surfaces preferably extend substantially parallel and preferably extend at least partially in a vertical direction;

g) wherein in the connected state of adjacent panels there is preferably a space (18) between at least part of the outer surface (16) of said panel (1) and at least part of the inner surface (17) of the adjacent panel (1).

- 14 045402

2. Panel (1) according to claim 1, characterized in that in the connected state of adjacent panels, the upper contact surfaces (14) define an internal vertical plane (19), while the inclined contact surfaces (15a, 15b) are located on the same side of said internal vertical plane (19).

3. Panel (1) according to point 1 or 2, characterized in that in the connected state of adjacent panels, the upper contact surfaces (14) define the internal vertical plane (19), while the inclined contact surfaces (15a, 15b) are located on the same the same side of the specified internal vertical plane (19).

4. Panel (1) according to one of the preceding claims, characterized in that in the connected state of adjacent panels, the upper contact surfaces (14) define an internal vertical plane (19), while the inclined contact surface (15a) of the downward directed tongue (7) passes by a maximum of 1 mm in the horizontal direction relative to the inner vertical plane (19).

5. Panel (1) according to one of the previous claims, characterized in that the length of the inclined contact surface (15) of the upwardly directed side surface (5) exceeds the length of the inclined contact surface (15) of the downwardly directed tongue (7), and preferably the length of the inclined the contact surface (15) of the upwardly directed side surface (5) is at least twice the length of the inclined contact surface (15) of the downwardly directed tongue (7).

6. Panel (1) according to one of the preceding paragraphs, characterized in that in the connected state of adjacent panels, the upper contact surfaces (14) define the inner vertical plane (19), while part (20) of the downwardly directed tongue (7), including it an inclined contact surface (15a) extends beyond the inner vertical plane (19), said portion (20) being substantially trapezoidal or wedge-shaped.

7. Panel (1) according to paragraph 6, characterized in that the height of said part (20) exceeds the width of said part, and preferably the maximum height of said part (20) is at least three times the maximum width of said part (20 ).

8. Panel (1) according to item 6 or 7, characterized in that the width of the space (18) is equal to or greater than the width of the specified part (20) of the downward tongue (20).

9. Panel (1) according to one of the previous paragraphs, characterized in that in the connected state of adjacent panels, the upper contact surfaces (14) define the internal vertical plane (19), while the inclined contact surfaces (15) are adjacent to the internal vertical plane (19 ).

10. Panel (1) according to any one of the preceding claims, characterized in that, in the connected state of adjacent panels, the bottom (21) of the downward directed tongue (7) contacts the upper side (22) of the upward directed groove (6) on the contact surface of the groove (23 ), and between the first (2) and second (3) connecting parts there is a gap (24) extending from the inclined contact surfaces (15) to the contact surface of the groove (23).

11. Panel (1) according to any one of the preceding claims, characterized in that, in the connected state of adjacent panels, the bottom (21) of the downwardly directed tongue (7) contacts the upper side (22) of the upwardly directed groove (6) in a preferably substantially horizontal manner , the contact surface of the groove (23), and between the first (2) and second (3) connecting parts there are gaps (24) on both sides of the specified contact surface of the groove (23).

12. Panel (1) according to any one of the preceding claims, characterized in that the upper surface (25) of the upwardly directed tongue (4) and the upper surface (26) of the downwardly directed groove (11) in the connected state are at least partially spaced from each other such that there is a gap (27) between the two surfaces (25, 26).

13. Panel (1) according to any of the preceding claims, characterized in that the upper contact surface (14) and the inclined contact surface (15) of the upwardly directed side surface (5) mutually form a first angle, and the upper contact surface (14) and the inclined the contact surface (15) of the downward tongue (7) mutually form a second angle, the first and second angles being within a difference of 20 degrees.

14. Panel (1) according to any one of the preceding claims, characterized in that the outer side (9) of the upwardly directed tongue (4) contains a first locking element (28), and the downwardly directed side surface (10) is provided with a second locking element ( 29), while in the connected state of adjacent panels (1) at least part of the first (28) and at least part of the second (29) fixing element are in contact, forming a fixing surface (30) for vertical fixation of panels (1) in relation to each other to friend.

15. Panel (1) according to item 14, characterized in that the first fixing element (28) is an outer convexity (28), and the outer side of the outer convexity (28) contains an upper part (31) and an adjacent lower part (32) wherein the lower portion (32) comprises an inclined locking surface (30a) and the upper portion (31) preferably comprises a curved guide surface (32').

- 15 045402

16. Panel (1) according to item 14 or 15, characterized in that the second locking element (29) is a recess (29) containing an upper part (33) and an adjacent lower part (34), wherein the lower part contains an inclined locking surface (30B).

17. Panel (1) according to claim 15 or 16, characterized in that the length of the inclined locking surface (30a) of the lower part (32) of the outer convexity (28) is greater, preferably at least 1.5 times greater than the inclined locking surface (30B) of the lower part (34) of the recess (29).

18. Panel (1) according to one of paragraphs 15-17, characterized in that the upper part (31, 33) extends over a larger vertical section compared to the lower part (32, 34), while the height of the upper part (31, 34) is preferable 33), is at least three times the height of the lower part (32, 34).

19. Panel (1) according to claim 18, characterized in that the parts of the first locking element (28) and the second element (29) of the locking element, which are in contact in a connected state with adjacent panels (1), are inclined locking surfaces ( 30, 30A, 30B) of the fixing elements (28, 29) and/or in the connected state of the panels (1) the upper parts (31, 33) of the first fixing element (28) and the second element (29) of the fixing elements are spaced at least partially.

20. Panel (1) according to any one of paragraphs 14-19, characterized in that the outer side (9) of the upwardly directed tongue (7) contains an upper outer part (35) and a lower outer part (36), wherein the first locking element ( 28) is located between the upper (35) and lower (36) outer parts, with the lower outer part (36) located closer to the inner side (8) of the upwardly directed tongue (4) compared to the upper outer part (35).

21. Panel (1) according to claim 20, characterized in that the upper outer part (35) is preferably substantially vertical and defines an outer vertical plane (37), with at least part of the first locking element (28) protruding from the outer vertical plane plane (37) at least partially, preferably a maximum of 2 mm in the horizontal direction.

22. Panel (1) according to one of paragraphs 14-21, characterized in that the outer side (9) of the upwardly directed tongue (7) contains an upper outer part (35), which defines the outer vertical plane (37), with the first fixing the element (28) comprises an outer convexity (28), wherein the outer side of the outer convexity (28) comprises an upper portion (31) and an adjacent lower portion (32), the upper portion (31) being located entirely on the side of said outer vertical plane ( 37) facing away from the upwardly directed side surface, and at the same time the lower part (32) intersects the outer vertical plane (37).

23. Panel (1) according to item 16 or 17 and item 22, characterized in that both the locking surface of the inclined surface (30B) of the lower part (34) of the recess (29) and the upper part (31) are completely located on the side of the specified outer vertical plane (37) facing away from the upwardly directed side surface.

24. Panel (1) according to one of claims 20-21, characterized in that the lower outer part (36) is at least partially, preferably substantially vertical, and the inclined fixing surface (30A) of the lower part (32) and the vertical portion of the lower outer portion (36) forms an angle (β) of 100 to 175 degrees.

25. The panel (1) according to claim 24, characterized in that the angle (a) formed between the upper contact surfaces and the inclined contact surfaces, and the angle (β) formed between the lower outer part (36) and the inclined fixing surface (30A) or the lower part (32), differ within 20 degrees and are preferably the same.

26. Panel (1) according to any one of paragraphs 14-25, characterized in that the outermost part (38) of the first locking element (28) is located at a horizontal level lower than the upwardly directed groove (6).

27. Panel (1) according to any of the preceding paragraphs, characterized in that it contains at least one third connecting part and at least one fourth connecting part located on another pair of opposite sides of the panel (1), while the third connecting part of the specified the panels and the fourth connecting part of the other panel (1) are preferably designed to be connected by means of an inclined downward movement.

28. Panel (1) according to paragraph 27, characterized in that the third connecting part contains:

a laterally directed tongue extending in a direction substantially parallel to the upper side of the core, at least one second downwardly directed side surface spaced from the sidewardly directed tongue, and a second downwardly directed groove formed between the sidewardly directed tongue and the second downwardly directed side surface , and the fourth connecting part contains:

a third groove configured to accommodate at least a portion of a laterally directed tongue of a third connecting profile of an adjacent panel, wherein said third groove is defined by an upper lip and a lower lip, wherein said lower lip is provided with an upwardly directed locking element, wherein the third the connecting part and the fourth connecting part are configured in such a way that two such panels are capable of being connected to each other by means of a rotational movement, wherein in the connected state: at least a portion of the laterally directed tongue of the first panel is inserted into a third groove of the adjacent second panel, and wherein at least a portion of the upwardly directed locking element of said second panel is inserted into a second downwardly directed groove of said first panel.

29. Panel (1) according to any of the preceding paragraphs, characterized in that panel (1) is a decorative panel containing:

at least one core layer, and at least one decorative top section directly or indirectly attached to said core layer, wherein the top section defines a top surface of the panel, a plurality of side edges formed at least in part by said core layer and/or side an upper section, wherein at least two opposite side edges are provided with a first connecting part and a second connecting part, respectively.

30. A covering, in particular a floor covering, comprising a plurality of interconnected panels (1) according to any of the preceding paragraphs.

The invention will now be explained on the basis of non-limiting examples of embodiments, which are illustrated in the following figures. Corresponding elements are designated in the figures by corresponding reference numerals. On the figures:

in fig. 1 schematically shows two interconnected panels with first and second connecting parts according to the present invention;

in fig. 2 schematically shows a first connecting part of a panel according to the present invention and FIG. 1;

in fig. 3 schematically shows a second connecting part of a panel according to the present invention and FIG. 1;

in fig. 4 schematically shows an embodiment of two interconnected panels with first and second connecting parts according to the present invention;

in fig. 5 is a schematic detail view of part A of the embodiment shown in FIG. 4; and in fig. 6 is a schematic detail view of part B of the embodiment shown in FIG. 4.

In fig. 1 shows a floor panel (1) containing a first connecting part (2) and a second connecting part (3) in a connected state. The first connecting part (2) includes an upwardly directed tongue (4), an upwardly directed side surface (5) lying at a distance from the upwardly directed tongue (4), and an upwardly directed groove (6) formed between the upwardly directed tongue (4) and upwardly directed side surface (5), while the upwardly directed groove (6) is adapted to the downwardly directed tongue (7) of the second connecting part (3) of the other panel (1). The side of the upward tongue (4) facing the upward side surface is the inner side (8) of the upward tongue (4), and the side of the upward tongue (4) facing away from the upward side surface (5) is with the outer side (9) of the tongue (4) pointing upward.

The second connecting part (3) includes a downward tongue (7), a downward side surface (10) lying at a distance from the downward tongue (7), and a downward groove (11) formed between the downward tongue (7) and side surface (10) pointing downwards. The side of the downward tongue (7) facing the downward side surface is the inner side (12) of the downward tongue (7), and the side of the downward tongue (7) facing away from the downward side surface (10) is with the outer side (13) of the downward-facing tongue (7).

The outer side (13) of the downward-facing tongue (7) and the upward-facing side surface (5) comprise an upper contact surface (14) on the top of the panel (1), with the upper contact surfaces (14) being in contact and extending vertically. Adjacent to the upper contact surfaces (14), both the downwardly directed tongue (7) and the upwardly directed side surface (5) comprise an inclined contact surface (15), the inclined contact surfaces (15) being in contact, the upper contact surfaces ( 14) on one side, and the inclined contact surfaces (15) of the upwardly directed side surface (5) and/or the outer side (13) of the downwardly directed tongue (7) on the other hand preferably make an angle (α) of about 125 degrees to each other. The upper contact surface (14) and the inclined contact surface (15) of the upwardly directed side surface (5) mutually form a first angle of about 125 degrees, and the upper contact surface (14) and the inclined contact surface (15) of the downward directed tongue (7) mutually make a second angle equal to about 125 degrees.

The downward directed tongue (7) adjacent to the inclined contact surface (15) contains an outer surface (16), and adjacent to the inclined contact surface (15) a directed

- 17 045402 up the side surface (5) contains an inner surface (17), while the outer (16) and inner (17) surfaces are parallel and vertical. There is a space (18) between the outer surface (16) and the inner surface (17).

The upper contact surfaces (14) define the inner vertical plane (19), wherein the inclined contact surface (15) of the downward directed tongue (7) extends beyond the inner vertical plane (19), and the inclined contact surface (15) of the upwardly directed side surface (5 ) lies inward compared to the inner vertical plane (19). A portion (20) of the downward tongue (7) extends beyond the inner vertical plane (19), said portion (20) being substantially trapezoidal or wedge-shaped. The inclined contact surfaces (15) are located entirely outside and adjacent to the inner vertical plane (19). Part (20) has an elongated vertical part compared to the horizontal part.

The bottom (21) of the downward tongue (7) contacts the upper side (22) of the upward groove (6) on the contact surface of the groove (23), and there is a gap (24) between the first (2) and second (3) connecting parts. , extending from the inclined contact surfaces (15) to the contact surface of the groove (23). Additionally, the upper surface (25) of the upwardly directed tongue (4) and the upper surface (26) of the downwardly directed groove (11) are spaced apart from each other such that there is a gap (27) between the two surfaces (25, 26).

The outer side (9) of the upwardly directed tongue (4) contains a first locking element (28) in the form of an outer convexity, and the downwardly directed side surface (10) is provided with a second locking element (29) in the form of a recess, with the first (28) and, at least a portion of the second (29) locking element is in contact and forms a surface of the locking element (30).

In fig. 2 and 3 show the first and second connecting parts separately. The outer side of the outer convex (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), the lower portion including an inclined locking surface (30B). The upper part (31, 33) extends over a larger vertical section compared to the lower part (32, 34).

The parts of the first (28) and second (29) locking element that are in contact are the inclined locking surfaces (30, 30A, 30B) of the locking elements (28, 29) and the upper parts (31, 33) of the first (28) and second (29) the locking elements are at least partially spaced.

The outer side (9) of the upwardly directed tongue (7) includes an upper outer part (35) and a lower outer part (36), with the first locking element (28) located between the upper (35) and the lower outer part (36). The lower outer portion (36) is located closer to the inner side (8) of the upwardly directed tongue (4) compared to the upper outer portion (35).

The upper outer portion (35) is substantially vertical and defines the outer vertical plane (37), with the first locking element (28) protruding from the outer vertical plane (37). The lower outer portion (36) is substantially vertical, and the inclined locking surface (30A) of the lower portion (32) and the lower outer portion (36) form an angle (β) of 100 to 175 degrees. The angle (α) formed between the upper contact surfaces and the inclined contact surfaces and the angle (β) formed between the lower outer part (36) and the inclined locking surface (30A) or the lower part (32) are approximately the same.

The outermost part (38) of the first locking element (28) is located at a horizontal level that is lower than the upwardly directed groove (6).

In fig. 4 schematically shows an embodiment of two interconnected panels (1) with first and second connecting parts according to the present invention. The panels (1) contain a first connecting part (2) and a second connecting part (3) in a connected state. The embodiment shown contains all of the elements shown in FIG. 1, and further includes a recess (40) located under the upper contact surface (14a) of the second connecting part (3). The recess (40) contains an upper inclined surface and a lower inclined surface. The lower inclined surface is aligned with the inclined contact surface (15a) of the downward directed tongue (7). The recess (40) can act as an expansion chamber to allow the panel material to swell, for example when exposed to heat and/or moisture, and further reduces the contact surface area in the top seam between the two panels (1), allowing for more visible clamping forces in the upper seam between said panels (1) to improve the waterproofing properties of the panel itself.

In fig. 5 is a schematic detail view of part A of the embodiment shown in FIG. 4, around the upper contact surfaces of two interconnected panels. The figure shows two points or areas of contact (41, 42) in which the engagement force (or clamping force) in that particular area of the connecting parts (2, 3) is higher than in other parts shown in these figures. These two

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Claims (16)

points or zones of intense contact (41, 42) lead to a significant improvement in water tightness and, therefore, to a further improvement in the water tight connection between said panels (1). The figure shows that the upper contact areas 14b and 14a are not completely parallel, but the upper contact area 14b is slightly inclined with respect to the opposite vertical upper contact area 14a and, in particular, extends (slightly) from the vertical upper contact area 14a in a downward direction. This does not necessarily mean that the upper contact areas 14a, 14b will separate from each other in a downward direction, but generally results in the contact between the upper portions of the upper contact areas 14a, 14b being more intense than the contact between the lower portions of the upper contact areas 14a , 14b. It is possible that, due to the locking force, the area on or around the inclined contact surface 15a of the downward tongue is elastically or plastically deformed during engagement of adjacent inclined contact surfaces. Locally, the area on or around the inclined contact surface 15b may also be elastically or plastically deformed. In fig. 6 is a schematic detail view of part B of the embodiment shown in FIG. 4, around the fixing elements (28, 29) of two interconnected panels. The upper outer portion (35) is substantially vertical and defines the outer vertical plane (37), with the first locking element (28) protruding from the outer vertical plane (37). The distance (39a) between the outermost part (38) of the first locking element (28) and the outer vertical plane (37) is substantially half the distance (39b) between the outermost part 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 an embodiment, the horizontal distance between the outer vertical plane (37) and the upper contact surface is equal to distance D. Distance 39b may be about 0.4 times greater than distance D, and distance 39a may be about 0.2 times greater than distance D. The serial numbers used in this document, such as first, second, third, etc., are used for identification purposes only. The panels according to the invention may also be called tiles. The core (core layer) of a panel may also be called a core (layer) and may consist of a number of sublayers, which may, for example, include a reinforcing layer such as a layer of fiberglass. Connecting parts may also be called connecting profiles or connecting profiles. By responsive connection profiles it is meant that these connection profiles can interact with each other. However, for this purpose, the mating connecting profiles do not necessarily have to have mating shapes. Fixation in the vertical direction means fixation in a direction perpendicular to the plane of the panel. By fixation in the horizontal direction we mean fixation in a direction perpendicular to the respective joined edges of the two panels and parallel to or coinciding with the plane defined by the panels. As used herein, the expressions foamed composite and foamed plastic material (or foamed material) are used interchangeably, wherein in fact a foamed composite is a foam mixture comprising at least one (thermo)plastic material and at least one filler (non-polymeric material). The above-described inventive concepts are illustrated by several exemplary embodiments. It is possible that certain teachings of the invention can be practiced without applying other details of the described example. It is not necessary to go into detail about every conceivable combination of the above-described inventive ideas, since one skilled in the art will appreciate that numerous inventive ideas can be (re)combined to achieve a particular application. The verb contain and its conjugations used in this patent publication are understood to mean not only contain, but are also understood to mean the phrases contain, essentially consist of, formed by and their conjugations. CLAIM 1. Panel (1), in particular a floor panel, comprising: a) at least one first connecting part (2) and at least one second connecting part (3) located on opposite sides of the panel (1), wherein the first connecting part (2) of said panel and the second connecting part (3 ) the other panel (1) is designed to be connected by means of a downward movement; b) wherein the first connecting part (2) contains an upwardly directed tongue (4), at least one upwardly directed side surface (5) lying at a distance from the upwardly directed tongue (4), and an upwardly directed groove (6) formed between the upwardly directed tongue (4) and the upwardly directed side surface (5), wherein the upwardly directed groove (6) is configured to receive at least part of the downwardly directed tongue (7) of the second connecting part (3) of the other panel (1) , while the side of the upward-directed tongue (4) facing the direction - 19 045402 the upward side surface is the inner side (8) of the upward tongue (4), and the side of the upward tongue (4) facing away from the upward side surface (5) is the outer side (9) of the upward tongue ( 4); c) wherein the second connecting part (3) comprises a downwardly directed tongue (7), at least one downwardly directed side surface (10) lying at a distance from the downwardly directed tongue (7), and a downwardly directed groove (11) formed between the downwardly directed tongue (7) and the downwardly directed side surface (10), wherein the downwardly directed groove (11) is configured to receive at least part of the upwardly directed tongue (4) of the first connecting part (2) of the other panel (1) , wherein the side of the downward tongue (7) facing the downward side surface (10) is the inner side (12) of the downward tongue (7), and the side of the downward tongue (7) facing away from the downward side surface ( 10), is the outer side (13) of the downward directed tongue (7); d) wherein both the outer side (13) of the downwardly directed tongue (7) and the upwardly directed side surface (5) comprise an upper contact surface (14) near or towards the upper side of the panel (1), (i) wherein both of the contact surfaces (14) extend completely vertically, or (ii) wherein the upper contact surface (14) of the downward-facing tongue (7) extends vertically, and wherein the upper contact surface (14) of the upward-facing side surface (5) is inclined downward in a direction from the upwardly directed tongue (4), and wherein the upper contact surface (14) of the outer side (13) of the downwardly directed tongue (7) of said panel is configured to engage with the upper contact surface (14) of the upwardly directed side surface (5) adjacent panel in the connected state of the panels (1), wherein the upper contact surfaces (14) represent the upper surfaces with which the panels (1) are in contact; e) wherein below, the upper contact surfaces (14) of both the downwardly directed tongue (7) and the upwardly directed side surface (5) comprise an inclined contact surface (15), wherein the inclined contact surface (15) of the downwardly directed tongue (7) ) of said panel is configured to engage with an inclined contact surface (15) of an upwardly directed side surface (5) of an adjacent panel in the connected state of said panels (1), wherein each vertical portion of the upper contact surface (14) and each adjacent inclined surface (15 ) mutually make the same angle (α) from 100 to 175°, while the specified vertical upper contact surface of the upwardly directed side surface (5) is adjacent to the specified inclined contact surface of the upwardly directed side surface (5); f) in this case, the downward directed tongue (7) adjacent to the inclined contact surface (15) contains an outer surface (16) located below the inclined contact surface (15) of the downward directed tongue (7), and at the same time adjacent to the inclined contact surface (15 ) the upwardly directed side surface (5) contains an inner surface (17) located below the inclined contact surface (15) of the upwardly directed side surface (5), while the outer (16) and inner (17) surfaces are substantially parallel and extend, at least partially in the vertical direction; g) in this case, in the connected state of adjacent panels, there is a space (18) between at least part of the outer surface (16) of the panel (1) and at least part of the inner surface (17) of the adjacent panel (1), while in the connected state of adjacent panels, the upper contact surfaces (14) define the inner vertical plane (19), with the inclined contact surfaces (15a, 15b) located on the side of the inner vertical plane (19) facing away from the upwardly directed tongue (4). 2. Panel (1) according to claim 1, characterized in that the vertical upper contact surface (14) of the downwardly directed tongue (7) and the inclined upper contact surface (14) of the upwardly directed side surface (5) mutually make an angle from 0 to 2 °, preferably from 0 to 1°, more preferably from 0 to 0.5°. 3. Panel (1) according to claim 1 or 2, characterized in that in the connected state of adjacent panels, the upper contact surfaces (14) define the internal vertical plane (19), while the inclined contact surfaces (15a, 15b) are located on one and the same side of the inner vertical plane (19), facing away from the upwardly directed tongue (4). 4. Panel (1) according to one of the previous paragraphs, characterized in that in the connected state of adjacent panels, the upper contact surfaces (14) define the internal vertical plane (19), while the inclined contact surface (15a) of the downward directed tongue (7) extends a maximum of 1 mm, preferably a maximum of 0.5 mm, more preferably a maximum of 0.2 mm, in the horizontal direction with respect to the inner vertical plane (19). 5. Panel (1) according to one of the preceding claims, characterized in that the length of the inclined contact surface (15) of the upwardly directed side surface (5) exceeds the length of the inclined contact surface (15) of the downwardly directed tongue (7), wherein preferably length tilt- - 20 045402 The specified contact surface (15) of the upwardly directed side surface (5) is at least twice the length of the inclined contact surface (15) of the downwardly directed tongue (7). 6. Panel (1) according to one of the preceding paragraphs, characterized in that in the connected state of adjacent panels, the upper contact surfaces (14) define the inner vertical plane (19), while part (20) of the downwardly directed tongue (7), including it the inclined contact surface (15a) extends beyond the inner vertical plane (19), wherein the portion (20) is substantially trapezoidal or wedge-shaped, preferably the height of the portion (20) being greater than the width of said portion, wherein, preferably, the maximum height of the portion (20) is at least three times the maximum width of the portion (20), and preferably the width of the space (18) is equal to or greater than the width of the portion (20) of the downward tongue (20). 7. Panel (1) according to one of the previous paragraphs, characterized in that in the connected state of adjacent panels, the upper contact surfaces (14) define the internal vertical plane (19), while the inclined contact surfaces (15) are adjacent to the internal vertical plane (19 ). 8. Panel (1) according to any one of the preceding claims, characterized in that in the connected state of adjacent panels, the bottom (21) of the downward tongue (7) contacts the upper side (22) of the upward groove (6) on the contact surface of the groove ( 23), and between the first (2) and second (3) connecting parts there is a gap (24) extending from the inclined contact surfaces (15) to the contact surface of the groove (23). 9. Panel (1) according to any one of the preceding claims, characterized in that, in the connected state of adjacent panels, the bottom (21) of the downward tongue (7) contacts the upper side (22) of the upward groove (6) in a preferably substantially horizontal manner contact surface of the groove (23), and between the first (2) and second (3) connecting parts there are gaps (24) on both sides of the contact surface of the groove (23). 10. Panel (1) according to any one of the preceding claims, characterized in that the upper surface (25) of the upwardly directed tongue (4) and the upper surface (26) of the downwardly directed groove (11) in the connected state are at least partially spaced from each other such that there is a gap (27) between the two surfaces (25, 26). 11. Panel (1) according to any one of the preceding claims, characterized in that the upper contact surface (14) and the inclined contact surface (15) of the upwardly directed side surface (5) mutually form a first angle, and the upper contact surface (14) and the inclined contact surface (15) of the downward directed tongue (7) mutually form a second angle, the first and second angles being within a difference of 20°. 12. Panel (1) according to any one of the preceding claims, characterized in that the outer side of the downward tongue (7) contains at least one recess between the upper contact surface (14) and the inclined contact surface (15a) of the downward tongue (7) , wherein in the connected state of adjacent panels, said recess is preferably located at a distance from the upper contact surface (14) of the upwardly directed side surface (5). 13. Panel (1) according to any of the preceding claims, characterized in that the outer side (9) of the upwardly directed tongue (4) contains a first locking element (28), and the downwardly directed side surface (10) is provided with a second locking element ( 29), while in the connected state of adjacent panels (1) at least part of the first (28) and at least part of the second (29) fixing element are in contact, forming a fixing surface (30) for vertical fixation of panels (1) along in relation to each other, wherein preferably the first locking element (28) is an outer convexity (28), the outer side of the outer convexity (28) preferably comprising 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) preferably contains a curved guide surface (32'). 14. Panel (1) as claimed in any one of the preceding claims, characterized in that the level of the inclined contact surfaces (15A, 15B) of the downward tongue (7) and the upward side surface (5) is higher than the level of the highest point of the upward tongue (4) ). 15. Panel (1) according to any of the preceding paragraphs, characterized in that it contains at least one third connecting part and at least one fourth connecting part located on another pair of opposite sides of the panel (1), wherein the third connecting part a portion of said panel and a fourth connecting portion of the other panel (1) are preferably configured to be connected by an inclined downward movement. 16. Panel (1) according to claim 15, characterized in that the third connecting part contains: a laterally directed tongue extending in a direction substantially parallel to the upper side of the core, at least one second downwardly directed side surface lying at a distance -