Panels, method for manufacturing panels, mixture and coating

Abstract

A method for manufacturing a set of panels, wherein said panels (1) comprise profiled edges with coupling parts, wherein said panels (1) comprises a first edge (3) and a second edge (2), wherein the method comprises the step of forming the coupling parts, and at least the following step: -applying a waterproof coating (14) on at least a part of the first edge (3), and preferably also on at least a part of the second edge (2), and waterproof coating (14) and / or mixture for panels (1).

Description

[0001] Panels, method for manufacturing panels, mixture and coating

[0002] The present invention relates to panels, such as floor panels, and a method for manufacturing panels. This invention also relates to a waterproof coating and a mixture for panels.

[0003] In particular the invention relates to panels that are used for assembling a floating floor covering. Floor panels of this kind are known for example from WO97 / 47834 and may be provided on two opposite edges with profiled edge regions that comprise milled coupling means that fit into one another, with which two floor panels of this kind can be coupled together on the respective edges, preferably without using glue. Optionally the coupling means may be configured with some pretension, which means that the contour of the coupling means is configured as somewhat overlapping, so that in the coupled state a stress arises that pushes the panels together. This pretension is advantageous for counteracting the formation of gaps after laying. The penetration of dust and moisture may also be limited thereby. In some cases the milling quality of the coupling means is insufficient to keep the seams permanently waterproof. Moreover, at the location of the corner points of such panels there is increased susceptibility to water penetration. The profiled edge regions of adjacent lateral edges cross at the location of the corners, and therefore it is possible that the milled coupling means may be absent or insufficient there.

[0004] The penetration of moisture into the seams of a floor covering that is assembled from panels may, in the case of panels with a moisture-sensitive substrate and / or top layer, such as a substrate based on MDF or HDF (medium or high density fibreboard) and / or a top layer comprising timber, lead to swelling and / or discoloration, which may be annoyingly visible on the decorative surface of such panels. In addition, such swelling of the substrate may in itself lead to accelerated wear of the floor surface. Furthermore, the penetration of moisture in the seams of a floor covering is problematic per se, even if neither the substrate nor the top layer is moisture sensitive. In such cases water may collect under the floor covering and this may give rise to mould formation and the unpleasant effects of that. It is known from W02008 / 078181 to treat the edges of a floor panel with an MDF or HDF substrate with a water-repellent substance that comprises a fluorinated polymer or copolymer. The substance in question is applied on the edge of the floor panel by means of a so-called vacumate, for example of the type as known from DE9202976U1.

[0005] The present invention aims firstly to offer alternative methods for manufacturing panels, wherein according to various preferred embodiments, a solution can be offered for one or more of the problems with the methods and / or panels from the prior art. In particular, one aim of the invention is to describe methods that allow optimal water resistance of panels to be obtained more easily.

[0006] The invention is described in the independent claims. Embodiments are described in the dependent claims.

[0007] The first aspect of the invention relates to a method for manufacturing a set of panels, wherein said panels comprise profiled edges with coupling parts which allow the panels from the set to be coupled to each other, wherein said panels comprise a first edge with a first coupling part, preferably a female coupling part, and a second edge with a second coupling part, preferably a male coupling part, said first coupling part of a first one of said panels and said second coupling part of a second one of said panels being couplable as such to couple said first one of said panels and said second one of said panels to each other, wherein the method comprises the step of forming the coupling parts, and at least the following step:

[0008] -applying a waterproof coating on at least a part of the first edge, and preferably also on at least a part of the second edge; wherein the waterproof coating is obtained by adding a first composition, said first composition comprising a crosslinker, to a lacquer, wherein the weight ratio of the dry matter weight crosslinker upon the total weight of the lacquer is preferably between 3: 1000 and 1 : 10, more preferably between 5: 1000 and 1 :20, for example between 1 : 100 and 3: 100. Said first composition can be added to said lacquer by bringing together said first composition and said lacquer in a mixing unit. This mixing unit can be a continuous mixing unit, but preferably this mixing unit is a batch mixing unit, e.g. a mixing unit comprising a vessel and a stirring mechanism. Said lacquer can also be present in a holding element such as a container, barrel or tank, wherein said first composition is added to said holding element, after which stirring takes place.

[0009] Here at least a portion of the first edge, and preferably also a portion of the second edge, comprises said waterproof coating. Preferably said waterproof coating is applied over the entire length of the first edge, and more preferably also the entire length of said second edge. After application of said waterproof coating upon said edge, said waterproof coating typically cures, e.g. hardens, and preferably forms a film-like layer, e.g. a coating, upon said edge. The panel thus preferably comprises a cured waterproof coating, and more preferably a film.

[0010] Preferably said waterproof coating also impregnates said portion of the respective edge upon which the waterproof coating is applied. In this manner, if water is able to penetrate the film-like layer, then said water can still be sufficiently repelled and damage to the respective edge can be avoided.

[0011] Curing of the waterproof coating is preferably a physical curing wherein at least a film-like layer, e.g. a film, is formed upon the respective edge. Said curing can be accelerated by heat, for example with the aid of infrared light or a hot air stream. For example, if the waterproof coating is water-based, heat can accelerate the evaporation of the water, such that formation of a said film is accelerated. Of course said curing can also comprise radical curing, for example if the lacquer is a UV polyurethane dispersion, wherein said radical curing then makes use of radiation, e.g. UV light or electron beam.

[0012] With a lacquer is indicated a mixture / dispersion that, when applied to a material, such as an edge of a panel, and allowed to dry / harden / cure, can form at least a film-like layer. Said lacquers can comprise pigments and / or dyes, such that a coloured film- like layer is formed. For panels, such as floor panels comprising a substrate and a top layer, a said lacquer can be applied upon a lowered edge, for example in the form of a chamfer or a bevel which extends from the top layer into the substrate. With such lacquer the lowered edge is given the desired color, as such forming aesthetic panels. Such a lacquer, when used for a lowered edge can be indicated as a bevel paint, a bevel lacquer or a bevel coating. A drawback of the known lacquers is that the filmlike layer is not watertight. On the contrary, such a film-like layer can lower the water-resistance of the lowered edge. This is especially a problem when the lowered edge extends into the substrate and the substrate is sensitive to moisture, for example when the substrate is a wood fiberboard or a particle board. Lacquers can include synthetic or natural resins such as alkyds, acrylics, acrylates, vinyl acetate / ethylene (VAE), polyurethanes, polyester, melamine resins, epoxy, silanes or siloxanes, oils, or mixtures thereof. For example a lacquer can be a water-based lacquer comprising one or more acrylate dispersions, optionally pigments and optionally additives, such as defoamers and / or thickeners. Said lacquer can be a water-based lacquer which is a mixture of different binders like polyurethanes and acrylates, optionally pigments and optionally additives, such as defoamers and / or thickeners. Said lacquer can be a styrene acrylate lacquer or can be an alkyd lacquer or can be a urethane modified alkyd lacquer or can be a carboxylated styrene-butadiene copolymer latex or can be an acrylic ester-styrene copolymer lacquer or can be a cationic acryl dispersion or can be, an oil, silicone modified PU alkyd emulsion.

[0013] Preferably the type or types of crosslinkers for the first composition is chosen, based on the composition of the lacquer. Preferably also the amount of crosslinker is chosen based on the composition of the lacquer.

[0014] By adding said first composition to a said lacquer, a coating is obtained which is very suitable to provide edges of panels with increased water-resistant properties, thus a waterproof coating is obtained. Said first composition comprises a crosslinker, such that the formed film-like layer will have more internal bonds, as such increasing the watertightness of the formed film-like layer. Said crosslinkers preferably increase the number of bonds in said formed film-like layer as such creating a more dense mase. Further by adding said first composition to a said lacquer, adhesion with the substrate can be promoted, such that the first composition can also act as adhesion promoter to form additional bonds with the respective edge, for example with the wood of the substrate, if the substrate is for example a wood fiberboard or a particle board, such as protect the substrate against moisture in an improved manner. Said method thus makes the panels less sensitive to water and enhances the water tightness of the panels.

[0015] This method according the first aspect can also be easily implemented in a production environment. It is easy to add said first composition to a said lacquer. Said lacquer can be a known lacquer or can be lacquer especially made for this method. The invention also relates to lacquers especially made for this method. The invention thus also relates to lacquers as such, which are suitable for this method, said lacquers being described throughout this description.

[0016] Preferably, applying said waterproof coating is subsequently to the step of forming the coupling parts. Thus first the coupling part is formed and then said waterproof coating is applied. Said waterproof coating can be applied upon the entire height of a said edge comprising said coupling part. Preferably however, said waterproof coating is only applied at an upper part of a said edge comprising said coupling part.

[0017] Said waterproof coating can be applied by one of following:

[0018] -application by spraying, by for example a spray head, a needle gun or a plasma torch; -application by a transfer wheel or transfer roll;

[0019] -application under vacuum;

[0020] -application with one or more paint nozzles.

[0021] If spraying is used, one can spray with a pressure above 3 bar, above 5 bar or above 8 bar or one can spray at a pressure of at most 2 bar or at most 1 bar, for example a pressure between 0,1 and 0,9 bar, or a pressure between 0,2 and 0,8 bar, such as a pressure of 0,5 bar or a pressure of 0,6 bar. For example, use can made of a spray gun which sprays at a pressure of between 7 and 20 bar, for example 7 to 8 bar or 10 to 15 bar. For example use can be made of needles which spray at a pressure of between 0,3 and 1,5 bar or more. The opening of a said needle can have a diameter of between 0,1 and 1,54 mm.

[0022] Said panels are preferably rectangular, either square or oblong, and comprise a substrate and a top layer. Said panels then can comprise at least a first pair of opposite edges with coupling parts, which allow two such panels to be coupled to each other, wherein in a coupled position a locking is created in a direction perpendicular to the plane of the coupled panels and / or in a direction in the plane of the panels and perpendicular to the coupled side edges, wherein the first pair of opposite edges comprise said first edge and said second edge. Said first coupling part can for example be a groove and said second coupling part can for example be a tongue. Further preferably the panels are provided with a second pair of opposite edges, wherein also said waterproof coating is applied on said second pair of opposites edges, and this in the same way as for the first pair of opposite edges. In this way, a very efficient method is obtained for making the edges of the panels watertight.

[0023] Preferably the coupling parts are configured as overlapping, so that during coupling of edges, coupling with pretension is obtained. Here the waterproof coating and the coupling parts enhance the water-resistance of coupled panels.

[0024] Said lacquer can comprise wetting agents, which allows to apply said waterproof coating in a uniform manner. If the latter is the case, said first composition does not have to comprise wetting agents, however this is not excluded. Said first composition can comprise wetting agents. The latter is especially beneficial if said lacquer does not comprise wetting agents. Preferably the waterproof coating comprises between 0,1 and 5 percent by weight of a wetting agent. The percent by weight is here preferably expressed based on the total weight of the waterproof coating. The presence of wetting agents ensures that the waterproof coating gets well spread over at least the part of the edge upon which it is applied. By making use of wetting agents, it is ensured that the desired watertight properties are always obtained, with little fluctuation in the quality of the manufactured panels trough-out the process. The wetting agents also have a moistening effect, so that a better adhesion is obtained. Said added wetting agents or said wetting agents of the lacquer can be alcohols, such as long-chain alcohols or 3,5-dimethyl-l-hexyn-3-ol. Preferably said wetting agents consist of 3,5-dimethyl-l-hexyn-3-ol. Preferably wetting agents migrate and / or evaporate away, such that the panels, when they are installed, no longer comprise said wetting agents. The invention also relates to a lacquer as such comprising wetting agents which migrate and / or evaporate away, e.g. a lacquer comprising 3,5- dimethyl- 1 -hexyn-3 -ol .

[0025] The weight ratio of the dry matter weight crosslinkers upon the total weight of the lacquer is preferably between 1 : 100 and 1 : 10. The total weight of the lacquer is preferably the weight including the water, if the lacquer is water-based, or including the solvent, if the lacquer is solvent-based. With a solvent is indicated a solvent different from water. Preferably the weight ratio of the dry matter weight crosslinkers upon the total weight of the lacquer is between 5: 1000 and 1 : 10 or between 1 : 100 and 1 : 10 or between 1 :50 and 1 :30, for example 1 :20. The amount of crosslinkers needs to be sufficient to enhance the formation of a sufficiently dense cured waterproof coating, however unwanted chemical reactions before application of said waterproof coating should be avoided.

[0026] A said lacquer can comprise:

[0027] -a binder, such as resin, a polyurethane and / or an acrylate;

[0028] -a solvent or water;

[0029] -preferably pigments and / or dyes;

[0030] -optionally wetting agents.

[0031] In a preferred embodiment, said lacquer is a water-based lacquer. Water-based lacquers can be more environmentally safe and safer to handle. A said water-based lacquer can for example comprise the following composition:

[0032] -30 to 70 wt% of a polyurethane dispersion;

[0033] -10 to 40 wt% of an acrylate dispersion;

[0034] -0.5 to 5 wt% of defoamers; -0 to 30 wt% of pigments and / or dyes or

[0035] -70 to 80 wt% of an acrylic dispersion

[0036] -1 to 3 wt% of wetting agents;

[0037] -3 to 7 wt% of wax;

[0038] -3 to 7 wt% of pigments and / or dyes;

[0039] -1 to 5 wt% of coalescing agents;

[0040] -8 to 12 wt% of fillers, such as calcium carbonate.

[0041] In a very preferred embodiment, the lacquer is a dispersion comprising an acrylate, a polyurethane, an alkyd resin or mixtures thereof. For example the binder of said lacquer can substantially comprise acrylates, such that the lacquer is indicated as an acrylate dispersion. The binder of said lacquer can substantially comprise polyurethanes, such that the lacquer is indicated as a polyurethane dispersion. Polyurethane dispersions (PUDs) are preferably polyurethane polymer resins dispersed in water. Said lacquers can thus be acrylate lacquers, polyurethane lacquers, polyurethane acrylate lacquers, acrylic lacquers. It is especially which such lacquers that crosslinkers can enhance the watertightness of a film formed by the waterproof coating. The lacquer can be an acrylic lacquer. Acrylic lacquers can have a fast drying time. Another example of a possible lacquer is a cationic acrylic lacquer having a small average particle size (e.g. 60 nm) and a low minimum film forming temperature. The lacquer can be a polyurethane lacquer. Preferably the lacquer comprises a mixture of different binders, for example a mixture of polyurethanes and acrylates.

[0042] Said crosslinkers are preferably chosen from the list of: isocyanates, aziridines, oxazolidines, oxazoles, carbodiimides, alkoxysilanes, and mixtures thereof. These are very useful for lacquers which are an acrylate dispersion or a polyurethane dispersion or comprise an alkyd resin. For example the first composition can be a solvent-based crosslinking agent based on aziridinic structure and preferably of an aliphatic nature. The first composition can be a water-based carbodiimide crosslinker or a solvent-based carbodiimide crosslinker, for example a carbodiimide crosslinker diluted in a methoxy propyl acetate. The first composition can also be a 100% liquid carbodiimide crosslinker. For example polycarbodiimide crosslinkers are very suitable for lacquers which are acrylate dispersions. (Poly)carbodiimides are preferred crosslinkers since they do not negatively influence pot life and they are relative harmless (e.g. with regard to carcinogenic, mutagenic and / or reprotoxic properties).

[0043] Preferably, adding the first composition to the lacquer takes place at most 24h before applying said waterproof coating, preferably at most 12h, most preferably at most 6h. This ensures that the desired quality of the waterproof coating, when applying said waterproof coating, is sufficient. The shelf life of a said waterproof coating can be ensured for at least 6 hours. Here the risk is low that the crosslinkers lose their functionality before the waterproof coating is applied. For example use can be made of hydrolysable crosslinkers, without the risk that the crosslinkers lose their functionality due to hydrolysation, before the waterproof coating is applied.

[0044] In a specific embodiment the dry matter of the first composition substantially comprises said crosslinker, for example comprises 95 wt% of crosslinker or only comprises said crosslinker. Said first composition can comprise a solvent or water. However said first composition cannot comprise a solvent or water, and then substantially comprises crosslinkers, said crosslinkers preferably being liquid crosslinkers. Crosslinkers can be dissolved in the lacquer, since a lacquer is normally water-based or solvent-based. By making sure that the mixing of the lacquer and the first composition takes place at most 24h before applying said waterproof coating, said solid crosslinkers will not settle.

[0045] In a specific embodiment the first composition is solvent based. For example the first composition can comprise between 20 and 70 wt% of crosslinker based on the total weight of the first composition. Preferably the lacquer is water-based and the first composition is solvent-based. With the aid of a solvent based first composition, a crosslinker which is less compatible with water can be added and can thus be present in the waterproof coating.

[0046] In a very specific embodiment the panels comprise a substrate and a top layer, wherein the first edge, and preferably also the second edge, comprises a lowered edge which extends from the top layer and preferably into the substrate, for example in the form of a chamfer or bevel, wherein the waterproof coating is at least applied upon said lowered edge and wherein the waterproof coating preferably forms a decoration separate from the top layer. Especially when the substrate is a moisture sensitive substrate, such as wood fiberboard or particle board, and when the lowered edge extends into the substrate, it is very beneficial to use the waterproof coating as indicated in the invention to obtain a waterproof lowered edge having said decoration. Said lowered edge having said decoration formed by the waterproof coating, can be indicated as a lacquered bevel or a painted bevel, wherein said lacquered bevel or painted bevel is the result of the method according to the first aspect of the invention and thus has good water tightness. Preferably said waterproof coating is also applied directly below said lowered edge, such to enhance the water resistant properties. Further preferably said lowered edge can be formed by means of a mechanical cutting operation with the aid of a knife or a milling device. Preferably the formation of said lowered edge and the application of said waterproof coating are done in the same continuous process. Preferably said waterproof coating forms a decoration separate from the top layer, because said waterproof coating comprises pigments and / or dyes. Said pigments and / or dyes can or cannot be the result of using a lacquer comprising pigments and / or dyes to form the waterproof coating. For example said lacquer can be transparent lacquer and said pigments and / or dyes can be added before, during or after adding the first composition to the lacquer. Said first composition can also comprise said pigments and / or dyes. Said waterproof coating could also be a transparent coating, such that the substrate is visible through said coating when applied upon a lowered edge that extends into the substrate. The substrate can have a desired appearance, for example the substrate can be greyish / dark coloured, e.g. a coloured wood fiber board. Further preferably the first edge comprises a sealing face preferably substantially perpendicular to the upper surface of the panel, and the second edge comprises a sealing face preferably substantially perpendicular to the upper surface of the panel. The first edge of the panel may be coupled to the second edge of another such panel, wherein in the coupled state the sealing face of the first edge of the panel is in contact with or is close to the sealing face of the second edge of the other such panel. Preferably said waterproof coating is at least applied upon a said sealing face. Through the contact of or the proximity of the sealing faces and because a said waterproof coating is also present at said sealing faces, good water resistance is obtained. If said first and / or second edge comprises also said lowered edge, then said sealing face is preferably directly located beneath said lowered edge.

[0047] In a specific embodiment the panels comprise a substrate and a top layer, wherein the first edge, and preferably also the second edge, comprises a lowered edge which extends from the top layer and preferably into the substrate, and by which said first and second edge form a recess which preferably extends into the substrate, wherein the waterproof coating is at least applied upon said recess, and wherein the waterproof coating is a transparent coating and / or a coloured coating. Said recess can be a gutter shaped recess, such as a U-shaped recess. Preferably said recess imitates a grout. Preferably said recess is a recess as described in WO 2022 / 097052. The coupling parts and recesses described in WO 2022 / 097052 are incorporated by reference. Preferably said waterproof coating is a coloured coating comprising pigments and / or dyes, such that the recess has a grout colour. Said substrate can already have the desired colour, for example can be greyish or black. This can be the case if the substrate comprises thermoplastic material, such as PVC, or if the woodbased substrate has a greyish / dark colour by adding pigments when manufacturing said wood-based substrate. If the substrate already has a good colour, use can be made of a transparent coating. If the substrate is not moisture sensitive, adding said waterproof coating is beneficial, since this waterproof coating can prevent water from entering the seams between panels and also said waterproof coating aids in stain resistance. In a preferred embodiment, the waterproof coating comprises pigments and / or dyes. For example said lacquer can comprise said pigments and / or dyes, by which said waterproof coating comprises said pigments and / or dyes. It is also possible that the lacquer is colourless and / or translucent. The benefit here is that a stock of different coloured lacquers is not needed for having different colours of waterproof coatings. For example said first composition can then comprise said pigments and / or dyes. It is also possible to add said pigments and / or dyes separately to the lacquer and this before, during and / or after adding of the first composition to the lacquer. With the aid of dyes / pigments the waterproof coating will give the edge upon which it is applied the desired colour. Said pigments and / or dyes can or cannot comprise carbon in the form of activated carbon, carbon black, carbon black nanotubes, or graphene.

[0048] In a preferred embodiment, the first composition comprises hydrophobic components and / or hydrophobic components are added, before, during and / or after adding of the first composition to the lacquer, to the lacquer. Here the waterproof coating not only forms a more watertight film, but also has water repellent properties. Water is thus also actively repelled from edges of coupled panels. Higher contact angles can be obtained. Said hydrophobic components preferably at least comprise metallic soaps. Said waterproof coating preferably comprises at least a binder comprising a polyurethane acrylate and / or an alkyd resin, water, metallic soaps, crosslinkers and optionally wax and optionally wetting agents. Said hydrophobic components can also be polymers such as hydrophobic polycarbodiimides, hydrophobic polyurethanes or hydrophobic acrylate polymers or hydrophobic polysilazanes, wherein the hydrophobic polymers preferably comprise at least one aliphatic hydrocarbon group, for example with 6 to 34 carbon atoms. Said aliphatic hydrocarbon group is preferably a linear hydrocarbon chain. The hydrophobic components can be amphiphilic copolymers. The hydrophobic components can comprise A-B-A block copolymers or other copolymers comprising A and B, wherein A is preferably an acrylate, e.g. a hydrophobic acrylate comprising for example a said aliphatic hydrocarbon group with 6 to 34 carbon atoms, and wherein B is a urethane, said urethane comprising or not comprising a carbodiimide group. Said urethane can be an octadecylurethane. The hydrophobic components can be or comprise silanes and / or (poly)siloxanes and / or polysilazanes and / or cyclic siloxanes and / or (modified) alkyd resins and / or (modified) acryl resins and / or benzoate esters and / or silica and / or metallic soaps and / or zinc stearates. For example the hydrophobic components can comprise propoxy silanes and / or ethoxy silanes and / or methoxy silanes. Ethoxy silanes and / or methoxy silanes can comprise hydroxylgroups which can bound with the hydroxylgroups of a wood based substrate. For example the hydrophobic components can comprise decamethylcyclopentasiloxane and / or 3- aminopropyltriethoxysilane and / or hexamethyldisilazane and / or organic polysilazanes and / or octadecyltri ethoxy silane and / or hexadecyltri ethoxy silane. The hydrophobic components can comprise N-ethyl-3 -trimethoxy silyl-2- methylpropanamine. The hydrophobic components can comprise polyurethane modified alkyd, acrylated alkyd, silicone-modified alkyd and / or thixotropic alkyd.

[0049] The hydrophobic components can comprise carnauba wax or paraffine wax or a wax comprising carnauba and paraffine.

[0050] The hydrophobic components can comprise silicone or silicone resin.

[0051] If said waterproof coating comprises at least a binder comprising a polyurethane acrylate and / or an alkyd resin, water, metallic soaps, crosslinkers and optionally wax and optionally wetting agents, then said waterproof coating preferably comprises between 1 and 3 wt% of metallic soaps. The following composition can be present: -between 25 and 70 wt% of binder;

[0052] -between 0 and 20 wt% of water;

[0053] -between 1 and 3 wt% of metallic soaps;

[0054] -between 0 and 7 wt% of wax, preferably between 2 and 6 wt%;

[0055] -between 0 and 7 wt% of wetting agents, preferably between 2 and 6 wt%;

[0056] -between 0,3 and 10 wt% of crosslinkers, for example between 0,5 and 3 wt%;

[0057] -between 0 and 5 wt% of thickener, such as a polyurethane thickener or acrylic associative thickener or acrylic thickener;

[0058] -between 0 and 5 wt% of defoamer;

[0059] -between 0 and 30 wt% of pigments. In a specific embodiment, a mixture comprising hydrophobic components is applied on at least a part of the first edge, and preferably also on at least a part of the second edge, wherein said mixture is different from said waterproof coating, such that at least a portion of the first edge, and preferably also a portion of the second edge, comprises both the waterproof coating and said hydrophobic components of the mixture. Said hydrophobic components can be hydrophobic components as indicated above. Here the mixture ensures the water-repellent properties, while the waterproof coating enhances watertightness. In this specific embodiment of the method, applying said waterproof coating can be performed before applying said mixture. Applying said mixture can also be performed before applying said waterproof coating. Applying said mixture and / or applying said waterproof coating can be done in two or more partial steps. If two or more of said partial steps are present, it is possible that applying said waterproof coating and / or applying said mixture is at least partially performed before applying respectively said mixture and / or waterproof coating and is also at least partially performed after applying respectively said mixture and / or waterproof coating.

[0060] In a specific embodiment, said first composition further comprises wax or wherein the waterproof coating is obtained by adding said first composition and wax to the lacquer. In a specific embodiment, said first composition further comprises wetting agents or wherein the waterproof coating is obtained by adding said first composition and wetting agents to the lacquer. In a specific embodiment, said waterproof coating comprises wax and wetting agents, wherein said first composition further comprises wax and / or wetting agents or wherein the waterproof coating is obtained by adding said first composition and wetting agents and / or wax, to the lacquer. Said wax can be an anionic paraffin. Said wax can be a carnauba wax. Said wax can be a paraffin wax. Said wax can be a hydrophobically modified synthetic wax. Said wax can be present in the form of a wax emulsion, for example a carnauba wax emulsion. The presence of wax provides the waterproof coating with water-repellent properties. Further preferably said wax is substantially present at the surface of the cured waterproof coating such that it can optimally perform its water-repellent properties. Said waterproof coating preferably comprises between 3 and 7 wt% of wax based on the dry matter weight of the waterproof coating. Said wetting agents ensures uniform application of said waterproof coating. Said wetting agents can be alcohols, such as long-chain alcohols or 3,5-dimethyl-l-hexyn-3-ol. Preferably said wetting agents migrate and / or evaporate away, such that the panels, when they are installed, no longer comprise said wetting agents. Said lacquer can already comprise wetting agents, such that said first composition could comprise wax but no wetting agents, or that said waterproof coating is obtained by only mixing said lacquer, said first composition and wax. Of course the combination of abovementioned hydrophobic components and wax and optionally wetting agents is possible for said first composition or for said waterproof coating. If wetting agents are presents, independent of their source -e.g. the lacquer or the first composition-, the waterproof coating preferably comprises between 1 and 4 wt% of wetting agents based on dry matter weight, for example comprises 2 wt% or 3 wt% of wetting agents.

[0061] In a preferred embodiment, said first composition comprises a non-VOC coalescing agent. With such a non-VOC coalescing agent excellent film formation is obtained, resulting in a watertight film upon said respective edge. Said non-VOC coalescing agent can for example be an ether such as dipropylene glycol dimethyl ether (DMM) or dipropylene glycol n-butyl ether (DPnB) or can be a diester such as 2,2,4- Trimethyl-1,3-Pentanediol Diisobutyrate.

[0062] In a very preferred embodiment the waterproof coating forms a film of less than 50 micrometer, preferably less than 25 micrometer. In this manner, the waterproof coating does not negatively influence the coupling of the panels. For example, this waterproof coating is very suitable to cover a lowered edge, such as a bevel or chamfer, of a panel. When applying said waterproof coating, it is difficult to only cover said lowered edge and also it can be beneficial to also treat the part of edge directly located below said lowered edge. When having such a thin film, coupling is not hindered by said waterproof coating, even when it is present upon coupling parts and / or sealing faces as described above. According to a second aspect, the invention relates to a method for manufacturing a set of panels, wherein said panels comprise profiled edges with coupling parts which allow the panels from the set to be coupled to each other, wherein said panels comprise a first edge with a first coupling part, preferably a female coupling part, and a second edge with a second coupling part, preferably a male coupling part, said first coupling part of a first one of said panels and said second coupling part of a second one of said panels being couplable as such to couple said first one of said panels and said second one of said panels to each other, wherein the method comprises the step of forming the coupling parts, characterized in that the method further comprises at least the following step:

[0063] -applying a waterproof coating on at least a part of the first edge, and preferably also on at least a part of the second edge; wherein the waterproof coating is obtained by adding a first composition to a lacquer, said first composition comprising one or more of the following components, preferably hydrophobic components and / or catalysts: polysiloxane, silicone, silane, fumed silica, metal soap, metal drier, metal carboxylate, or wax, wherein the weight ratio of the dry matter weight of said polysiloxane, silicone, silane, fumed silica, metal soap, metal drier, metal carboxylate, or wax of the first composition upon the total weight of the lacquer is preferably between 1 : 1000 and 1 : 10, more preferably between 1 :500 and 6: 100, most preferably between 1 : 100 and 5: 100, for example is between 2: 100 and 1 : 10 or between 3: 100 and 6: 100.

[0064] Said first composition can or cannot be a first composition as disclosed in the first aspect of the invention, e.g. can or cannot comprise a said crosslinker. Said specific hydrophobic components, such as polysiloxane, silicone, silane, fumed silica, metal soap or wax, added to said lacquer, have been found to repel water from edges of coupled panels in a very efficient way. Higher contact angles can be obtained. Said specific catalysts such as metal drier or metal carboxylate have been found to enhance the film formation and as such enhance water-repellent properties. The metal soap can for example be zinc soap. The metal carboxylate can bismuth neodecanoate. The metal drier can be a manganese drier. Regardless of whether the second aspect is or is not in accordance with the first aspect, embodiments / features of the first aspect of the invention not relating to the crosslinkers as such, apply mutatis mutandis for the second aspect of the invention and vice versa.

[0065] Preferably, if the first composition comprises two or more of the above-mentioned hydrophobic components and / or catalysts, said hydrophobic components and / or catalysts are firstly added together and then as a whole added to said lacquer. However, it is also possible to add these hydrophobic components and / or catalysts separately to the lacquer to form said waterproofing coating. For example, the first composition can comprise a silicone emulsion and a wax emulsion, wherein said silicone emulsion and wax emulsion are each separately added to said lacquer. If two or more two or more of the above-mentioned hydrophobic components are added to said lacquer, one could also state that the waterproof coating is obtained by

[0066] -adding a first composition to the lacquer, said first composition comprising one of the list of the following hydrophobic components and / or catalysts: polysiloxane, silicone, silane, fumed silica, metal soap, metal drier, metal carboxylate, or wax, wherein the weight ratio of the dry matter weight of said hydrophobic component and / or catalyst of the first composition upon the total weight of the lacquer is preferably between is preferably between 1 : 1000 and 1 : 10, more preferably between 1 :500 and 6: 100, most preferably between 1 : 100 and 5: 100; and

[0067] -adding a second composition to a lacquer, said second composition comprising one of the list of the following hydrophobic components and / or catalysts: polysiloxane, silicone, silane, fumed silica, metal soap, metal drier, metal carboxylate, or wax, wherein the weight ratio of the dry matter weight of said hydrophobic component and / or catalyst of the second composition upon the total weight of the lacquer is preferably between 1 : 1000 and 1 :10, more preferably between 1 :500 and 6: 100, most preferably between 1 : 100 and 5: 100; and wherein the first composition differs from the second composition. Preferably said lacquer is a water-based lacquer. Water-based lacquers can be more environmentally safe and safer to handle. A said water-based lacquer can for example comprise the following composition:

[0068] -30 to 70 wt% of a polyurethane dispersion;

[0069] -10 to 40 wt% of an acrylate dispersion;

[0070] -0.5 to 5 wt% of defoamers;

[0071] -0 to 30 wt% of pigments and / or dyes; or

[0072] -70 to 80 wt% of an acrylic dispersion

[0073] -1 to 3 wt% of wetting agents;

[0074] -3 to 7 wt% of wax;

[0075] -3 to 7 wt% of pigments and / or dyes;

[0076] -1 to 5 wt% of coalescing agents;

[0077] -8 to 12 wt% of fillers, such as calcium carbonate.

[0078] Said lacquer can be a dispersion comprising an acrylate, a polyurethane, an alkyd resin or mixtures thereof, and preferably is an acrylate lacquer or a polyurethane lacquer.

[0079] In a preferred embodiment, said first composition at least comprises silicone and / or polysiloxane, and preferably also comprises a wax. Said first composition can for example be combination of a water-based polysiloxane emulsion and a wax emulsion. To form said waterproofing coating, said water-based polysiloxane emulsion and a wax emulsion can be added separately to the lacquer, or said waterbased polysiloxane emulsion and said wax emulsion can firstly be added together and as a whole added to said lacquer. All the substances of the first composition do not have to be added to the lacquer in one single step. Said first composition can for example be combination of a water-based silicone emulsion and a wax emulsion. It has been found that such a preferred combination significantly increases water- repellent properties and ensures high contact angles at the height of the applied waterproof coating. The first composition can for example be a silicone emulsion. Said first composition can be a combination of a silicone emulsion and a wax emulsion. Said wax can be chosen from paraffin, carnauba, palm oil, rape seed or bee wax. Said wax is preferably added to the first composition in the form of a waterbased wax emulsion. The ratio silicone and / or polysiloxane upon the total weight of the first lacquer can be between 2 and 10 wt%. The ratio wax upon the total weight of the first lacquer can be between 2 and 10 wt%.

[0080] Preferably adding the first composition to the lacquer takes place at most 24h before applying said waterproof coating, preferably at most 12h, most preferably at most 6h.

[0081] Preferably the first composition is water-based, and is preferably a water-based emulsion, for example comprises two or more water-based emulsions. Said first composition can be well homogeneously mixed with said lacquer in a good manner, if said lacquer is also water-based.

[0082] Preferably the panels comprise a substrate and a top layer, and wherein the first edge, and preferably also the second edge, comprises a lowered edge which extends from the top layer and preferably into the substrate, for example in the form of a chamfer or bevel, wherein the waterproof coating is at least applied upon said lowered edge and wherein the waterproof coating preferably forms a decoration separate from the top layer. Preferably said waterproof coating is also applied directly below said lowered edge, such to enhance the water resistant properties. Further preferably said lowered edge can be formed by means of a mechanical cutting operation with the aid of a knife or a milling device. Preferably the formation of said lowered edge and the application of said waterproof coating are done in the same continuous process.

[0083] Said waterproof coating can comprise pigments and / or dyes. Such a waterproof coating is well capable of providing a said lowered edge with a separate decoration.

[0084] In a specific embodiment a mixture comprising hydrophobic components is applied on at least a part of the first edge, and preferably also on at least a part of the second edge, wherein said mixture is different from said waterproof coating, such that at least a portion of the first edge, and preferably also a portion of the second edge, comprises both the waterproof coating and said hydrophobic components of the mixture. Said hydrophobic components can be hydrophobic components as indicated above for the mixture described in the first aspect of the invention. Here the waterproof coating ensures watertightness and water-repellent properties, and the mixture further enhances water-repellent properties. In this specific embodiment of the method, applying said waterproof coating can be performed before applying said mixture. Applying said mixture can also be performed before applying said waterproof coating. Applying said mixture and / or applying said waterproof coating can be done in two or more partial steps. If two or more of said partial steps are present, it is possible that applying said waterproof coating and / or applying said mixture is at least partially performed before applying respectively said mixture and / or waterproof coating and is also at least partially performed after applying respectively said mixture and / or waterproof coating.

[0085] In a specific embodiment said first composition further comprises wetting agents or wherein the waterproof coating is obtained by adding said first composition and wetting agents to the lacquer. Said wetting agents ensures uniform application of said waterproof coating. Said wetting agents can be alcohols, such as long-chain alcohols or 3,5-dimethyl-l-hexyn-3-ol. Preferably said wetting agents migrate and / or evaporate away, such that the panels, when they are installed, no longer comprise said wetting agents.

[0086] Preferably the waterproof coating forms a film of less than 50 micrometer, preferably less than 25 micrometer.

[0087] In a specific embodiment, said first composition, in addition to a said hydrophobic component or as an alternative to a said hydrophobic component, can comprise a said catalyst. If said lacquer is a polyurethane lacquer, then said catalyst is preferably a polyurethane catalyst and / or a metal carboxylate, such as bismuth neodecanoate. The catalyst can also be metal drier, such as manganese drier. The ratio catalyst upon the total weight of the lacquer is preferably between 0,1 and 1 wt%.

[0088] If the hydrophobic components of the first composition comprise fumed silica, the ratio fumed silica upon the total weight of the lacquer is preferably between 0,1 and 1 wt%.

[0089] Preferred embodiments for the first composition of the second aspect of the invention are indicated below (with wt% based on the total weight of the lacquer). For all these embodiments a significant increase of the contact angle for the edge upon which said waterproofing coating was applied, was observed, when such a first composition was added to the lacquer.

[0090] Embodiment one:

[0091] -between 3 and 20 wt%, preferably between 4 and 10 wt%, of a water-based emulsion of polysiloxane, with a dry matter weight of between 30 and 70 wt%.

[0092] Embodiment two:

[0093] -between 3 and 20 wt%, preferably between 4 and 10 wt%, a water-based emulsion of a silicone resin, with a dry matter weight of between 30 and 70 wt%.

[0094] Embodiment three:

[0095] -between 3 and 15 wt%, preferably between 4 and 10 wt% of a wax emulsion comprising paraffin and carnauba, with a dry matter weight of between 40 and 80 wt%; and

[0096] -between 3 and 15 wt%, preferably between 4 and 10 wt%, of a water-based emulsion of a silicone resin, with a dry matter weight of between 30 and 70 wt%.

[0097] Embodiment four:

[0098] -between 3 and 15 wt%, preferably between 4 and 10 wt% of a wax emulsion comprising paraffins, with a dry matter weight of between 30 and 70 wt%; and -between 3 and 20 wt%, preferably between 4 and 10 wt%, of a water-based emulsion of polysiloxane, with a dry matter weight of between 30 and 70 wt%.

[0099] Embodiment five:

[0100] -between 3 and 15 wt%, preferably between 4 and 10 wt% of a wax emulsion comprising paraffins, with a dry matter weight of between 30 and 70 wt%; and -between 3 and 20 wt%, preferably between 4 and 10 wt%, of a water-based emulsion of polysiloxane, with a dry matter weight of between 30 and 70 wt%; and

[0101] -between 0,1 and 2 wt%, preferably between 0,3 and 1 wt% of a catalyst, preferably a metal carboxylate, such as bismuth neodecanoate.

[0102] Significant enhancing of the contact angle was observed, especially if the lacquer was a polyurethane lacquer and the catalyst a polyurethane catalyst, such as a metal carboxylate, e.g. bismuth neodecanoate.

[0103] Embodiment six:

[0104] -between 3 and 20 wt%, preferably between 4 and 10 wt%, of a water-based emulsion of polysiloxane, with a dry matter weight of between 30 and 70 wt%.%; and -between 0,1 and 1 wt% of fumed silica.

[0105] According to a third aspect, the invention relates to a method for manufacturing a set of panels, wherein said panels comprise profiled edges with coupling parts which allow the panels from the set to be coupled to each other, wherein said panels comprises a first edge with a first coupling part, preferably a female coupling part, and a second edge with a second coupling part, preferably a male coupling part, said first coupling part of a first one of said panels and said second coupling part of a second one of said panels being couplable as such to couple said first one of said panels and said second one of said panels to each other, wherein the method comprises the step of forming the coupling parts, and at least the following step: -applying a mixture comprising hydrophobic components on at least a part of the first edge, and preferably also on at least a part of the second edge; wherein the mixture comprises carbon in the form of graphene, carbon black or activated carbon or carbon nanotubes, and wherein preferably the dry matter of said mixture comprises between 0.1 wt% and 2 wt% of said carbon. For example between 0, 1 and 1 wt% of carbon nanotubes can be present. Said carbon can or cannot be a hydrophobic component. Preferably said mixture comprises hydrophobic components different from said carbon, and said carbon.

[0106] Said method according to the third aspect of the invention, is preferably also according to the first aspect and / or the second aspect of the invention. Preferably a portion of the first edge, and preferably also a portion of the second edge, comprises then both the cured waterproof coating and the cured mixture, e.g. comprises at least said hydrophobic components of the mixture and a film formed by the waterproof coating. Said mixture described in the third aspect of the invention can be the mixture described in the first and / or the second aspect of the invention, namely said mixture of the first and / or the second aspect of the invention comprising hydrophobic components, wherein said mixture is different from said waterproof coating. Thus all the embodiments / features of said mixture of the first and / or the second aspect of the invention can apply mutatis mutandis for this mixture of the third aspect of the invention and vice versa.

[0107] The mixture used in the third aspect of the invention is also an invention as such.

[0108] Said mixture can be applied by one of following:

[0109] -application by spraying, by for example a spray head, a needle gun or a plasma torch; -application by a transfer wheel or transfer roll;

[0110] -application under vacuum;

[0111] -application with one or more paint nozzles.

[0112] If spraying is used, one can spray with a pressure above 3 bar, above 5 bar or above 8 bar or one can spray at a pressure of at most 2 bar or at most 1 bar, for example a pressure between 0,1 and 0,9 bar, or a pressure between 0,2 and 0,8 bar, such as a pressure of 0,5 bar or a pressure of 0,6 bar. For example, use can made of a spray gun which sprays at a pressure of between 7 and 20 bar, for example 7 to 8 bar or 10 to 15 bar. For example use can be made of needles which spray at a pressure of between 0,3 and 1,5 bar or more. The opening of a said needle can have a diameter of between 0,1 and 1,54 mm.

[0113] The mixture according to the third aspect of the invention is preferably a solventbased mixture. Especially with solvent-based mixtures said carbon is beneficial, since the risk of settling of said carbon in a solvent-based mixture is low. With the aid of solvents, hydrophobic components are present at the surface of the edges, but hydrophobic components can also impregnate said edges, e.g. when said edge comprises a moisture sensitive substrate such as wood fiberboard or particle board. The latter is very beneficial for obtaining excellent water-resistant properties. Said solvent-based mixture can for example comprise hydrophobic polyurethane and an alkyd resin. The mixture can for example comprise 30 wt% of hydrophobic polyurethane, 37 wt% of solvent comprising hydrocarbons with 11 to 14 carbons, 5 wt% of co-solvent 2-ethylhexylacetate, 25 wt% of a long-oil alkyd resin, 2 wt% of 2-ethylhexyl titanate or TNBT and 1 wt% of a said carbon, or comprise 50 wt% of hydrophobic polyurethane, 24 wt% of solvent comprising hydrocarbons with 15 to 20 carbons, 13 wt% of white mineral oil, 5 wt% of co-solvent 2-ethylhexylacetate, 1,5 wt% of 2-ethylhexyl titanate or TNBT, 0,5 wt% of octadecyltriethoxysilane, 0,5 wt% of a said carbon, or comprise 48 wt% of hydrophobic polyurethane, 21 wt% of solvent comprising hydrocarbons with 11 to 14 carbons, 21 wt% of co-solvent 2- ethylhexylacetate, 2 wt% of a said carbon and 1,5 wt% hydrophobic fumed amorphous silica.

[0114] The mixture can for example comprise 7 wt% of hydrophobic polyurethane, 49 wt% of solvent comprising hydrocarbons with 11 to 14 carbons, 16 wt% of co-solvent 2- ethylhexylacetate, 25 wt% of a long-oil alkyd resin, 2 wt% of 2-ethylhexyl titanate or TNBT and 1 wt% of a said carbon, or comprise 12,5 wt% of hydrophobic polyurethane, 49 wt% of solvent comprising hydrocarbons with 15 to 20 carbons, 13 wt% of white mineral oil, 23 wt% of co-solvent 2-ethylhexylacetate, 1,5 wt% of 2- ethylhexyl titanate or TNBT, 0,5 wt% of octadecyltri ethoxy silane, 0,5 wt% of a said carbon, or comprise 12 wt% of hydrophobic polyurethane, 45,5 wt% of solvent comprising hydrocarbons with 11 to 14 carbons, 39 wt% of co-solvent 2- ethylhexylacetate, 2 wt% of a said carbon and 1,5 wt% hydrophobic fumed amorphous silica.

[0115] The solvents can comprise one or more of: a glycol ether, propylene glycol methyl ether, propylene glycol methyl ether acetate, hydrocarbons - preferably aliphatic hydrocarbons and / or preferably iso-hydrocarbons -, butyl acetate, propyl acetate - for example 3 -methoxy-3 -methyl- 1 -butyl acetate (MMB-AC) or 1 -methoxy -propyl acetate (MPA) -, 2-ethylhexylacetate, a dibasic ester, a glycol diether, a benzoate ester, a phthalate ester or a tetramethoxy ether. Solvents being or comprising benzoate esters have been found to provide mixtures with good water repelling properties. The solvent-based mixture can comprise for example alkanes, such as isoalkanes or branched alkanes or aliphatic hydrocarbons. The alkanes preferably have 10 to 20 carbon atoms, for example between 11 and 14 carbon atoms or between 15 and 20 carbon atoms. In order to increase the flash point, use may be made of 3- methoxy-3 -methyl -1 -butanol acetate. Thus, the mixture may for example comprise between 8 and 12 wt% of 3 -methoxy-3 -methyl- 1 -butanol acetate. If the mixture is solvent based, the dry matter content of the mixture is preferably between 5 and 20 percentage by weight, or for example between 10 and 15 percentage by weight.

[0116] The aforementioned solvent-based mixture comprises for example one or more of the following solvents: ethylhexyl acetate, propyl acetate or butyl acetate - for example 3 -Methoxy-3 -Methyl- 1 -Butyl Acetate (MMB-AC) or 1 -Methoxy Propyl Acetate (MPA) -, triethyl citrate, propylene glycol methyl ether, propylene glycol methyl ether acetate, 2-ethylhexylacetate, dibasic ester, glycol diether, benzoate ester, phthalate ester, dipropylene glycol dimethyl ether or a tetramethoxy ether. These components may or may not be indicated as cosolvents. For example the mixture can comprise between 20 and 25 wt% of solvents, e.g. solvents comprising alkanes, and between 20 and 25 wt% of cosolvents, e.g. 2-ethylhexyl acetate. The use of such solvents is preferred because good stability of the mixture is obtained, necessary for the processability thereof; and because good impregnation of the edge(s) of the panel with the mixture is obtained.

[0117] Preferably, the panels comprise at least a substrate and a top layer, wherein said mixture is at least applied upon said substrate and wherein at least part of the mixture penetrates into the substrate of said respective edge to a certain depth, for example penetrates at least 1 mm or between 0,1 mm and 0,5 mm. More preferably at least part of the hydrophobic components is present at the surface and most preferably the hydrophobic components at least have parts that are directed away from the panel, for example are directed outwards. If the hydrophobic components comprise said aliphatic hydrocarbon groups with for example 6 to 34 carbon atoms, these aliphatic hydrocarbon groups are preferably directed outwards, such that they are very well suited to provide the panels with water repellent properties. More preferably at least part of the hydrophobic components has penetrated the side edge, e.g. are present between the wood fibers or wood chips if the panels comprise a wood fiberboard or particle board substrate, such to provide the side edge with good water-repellent properties. It has been found that the best water-repellent properties are obtained when at least part of the hydrophobic components is present at the surface of the waterproof coating (if also said waterproof coating is present) and at least part of the hydrophobic components have penetrated the side edge.

[0118] Carbon black provides the mixture with a dark color, such that said mixture can darken said respective edge and for example can cover certain parts of the edge. For example a said mixture comprising carbon black is very suitable for application upon a lowered edge, for example in the form of a chamfer or a bevel, of a panel comprising a substrate and a top layer, wherein said lowered edge extends from the top layer into the substrate. Such a decorative top layer can comprise a white / yellow paper with a decor printed upon it. With such a mixture, the white line formed by said paper can be covered. Further carbon black contributes to the watertightness of the edge comprising said cured mixture. Also with carbon black, mixtures having a good shelf life can be made. 1

[0119] Graphene contributes to the watertightness of the edge comprising said cured mixture, since graphene forms a maze through which water cannot easily move. Activated carbon enhances the water-repellent properties of the mixture.

[0120] Preferably the mixture is a solvent-based mixture. Said carbon is preferably dissolved in a solvent and added in this form to form a said mixture. With the aid of solvents, curing can be performed smoothly. The mixture can comprise a solvent with a flashpoint of at least 60 °C, preferably at least 80°C, for example at least 100°C, for example at least 120°C and / or wherein preferably the mixture is VOC (volatile organic solvents) free or comprises at most 1 percent by weight of VOC’ s.

[0121] Said mixture can comprise between 0,1 and 5 percent by weight of a wetting agent. Said wetting agent can be an alcohol, such as a long-chain alcohol or 3,5-dimethyl- l-hexyn-3-ol. Preferably said wetting agent migrates and / or evaporates away, such that the panels, when they are installed, no longer comprise said wetting agent.

[0122] If also a said waterproof coating is applied, applying said waterproof coating can be performed before applying said mixture. For example first said waterproof coating can be applied and further at least partially dried with for example IR light, after which the mixture is applied. The latter is beneficial when the waterproof coating is water-based and the mixture is solvent-based. However, applying said mixture can also be performed before applying said waterproof coating. The latter can be beneficial when said mixture is solvent-based and said waterproof coating is waterbased, since no additional drying step is needed between applying said mixture and applying said waterproof coating. Applying said mixture and / or applying said waterproof coating can or cannot be done in two or more partial steps. If two or more of said partial steps are present, it is possible that applying said waterproof coating and / or applying said mixture is at least partially performed before applying respectively said mixture and / or waterproof coating and is also at least partially performed after applying respectively said mixture and / or waterproof coating. According to a fourth aspect, the invention relates to a method for manufacturing a set of panels, wherein said panels comprise profiled edges with coupling parts which allow the panels from the set to be coupled to each other, wherein said panels comprises a first edge with a first coupling part, preferably a female coupling part, and a second edge with a second coupling part, preferably a male coupling part, said first coupling part of a first one of said panels and said second coupling part of a second one of said panels being couplable as such to couple said first one of said panels and said second one of said panels to each other, wherein the method comprises the step of forming the coupling parts, and at least the following further step: applying a mixture on at least a part of the first edge, and preferably also on at least a part of the second edge; wherein said mixture comprises a hydrophobic polymer, such as a polycarbodiimide, a titanate -such as tetra n-butyl titanate (TNBT)-, and one or more solvents. Surprisingly it was found that with such a mixture, a said edge can be provided with superior water-repellent properties. Said polycarbodiimide is preferably comprises one or more aliphatic hydrocarbon groups, for example with 6 to 34 carbon atoms. A said aliphatic hydrocarbon group is preferably a linear hydrocarbon chain.

[0123] Preferably the solvents comprise alkanes, said alkanes having preferably 12 to 16 carbons, and further one or more co-solvents chosen from the list of: hydrophobic glycol ethers - such as propylene glycol n-butyl ether-, dipolar aprotic solvents -such as l-butylpyrrolidin-2-one-. For the abovementioned mixtures, excellent results for enhancing the water repellent properties of panel edges have been obtained with such combination of solvents.

[0124] Preferably said solvents are a combination of alkanes, glycol ethers and dipolar aprotic solvents. Preferably the amount of glycol ethers is lower than the amount of alkanes and preferably is at most 50% of the amount of alkanes. Preferably the amount of dipolar aprotic solvents is lower than the amount of alkanes and preferably is at most 50% of the amount of alkanes. Preferably the amount of glycol ethers is within 10% of the amount of aprotic solvents and preferably is substantially the same. In an embodiment the solvents comprise dipolar aprotic solvents and optionally a cosolvent such as an acetate, for example 2-ethylhexylacetate. If the latter is the case, said mixture preferably comprises between 30 and 40 wt% of a said dipolar aprotic solvent and between 5 and 10 wt% of said co-solvent.

[0125] Preferably, for all the embodiments of the fourth aspect, the mixture comprise a resin, preferably an alkyd resin, wherein the mixture comprises between 10 and 40 wt% of said resin. Said resin can also be an polyurethane resin or an acrylate resin. Excellent water resistance and good stability is obtained when an alkyd resin, such as a long oil alkyd resin is used.

[0126] Preferably the solvents are present in the mixture between 20 and 50 wt%.

[0127] Said mixture can or cannot be mixture as described in the first and / or second and / or third aspect of the invention.

[0128] Preferred formulations of this mixture for the fourth aspect of the invention are the following:

[0129] -between 25 and 40 wt% -preferably between 30 and 35 wt%- of hydrophobic polymer, preferably hydrophobic polycarbodiimide. Said hydrophobic polymer provides water resistance;

[0130] -between 10 and 35 wt% -preferably between 22 and 27 wt%- of an alkyd resin. Said alkyd resin enhances film formation;

[0131] -between 15 and 35 wt% -for example 20 wt% or 30 wt%- of alkane solvent, wherein said alkane solvent is preferably VOC free and comprises between 12 to 16 carbons;

[0132] -between 2 and 15 wt% -for example 5 wt% or 10 wt%- of a dipolar aprotic solvent, such as l-butylpyrrolidin-2-one;

[0133] -between 2 and 15 wt% -for example 5 wt% or 10 wt%- of a glycol ethers, such as propylene glycol n-butyl ether; -between 1 and 5 wt% of TNBT. TNBT is a good catalyst which enhances film formation;

[0134] -between 15 and 35 wt% of an alkane solvent, said alkanes having preferably 12 to 16 carbons.

[0135] -between 6 and 10 wt% -preferably between 7 and 9 wt%- of hydrophobic polymer, preferably hydrophobic polycarbodiimide. Said hydrophobic polymer provides water resistance;

[0136] -between 10 and 35 wt% -preferably between 22 and 27 wt%- of an alkyd resin. Said alkyd resin enhances film formation;

[0137] -between 15 and 48 wt% -for example 20 wt% or 30 wt%- of alkane solvent, wherein said alkane solvent is preferably VOC free and comprises between 12 to 16 carbons;

[0138] -between 2 and 15 wt% -for example 5 wt% or 10 wt%- of a dipolar aprotic solvent, such as l-butylpyrrolidin-2-one;

[0139] -between 2 and 15 wt% -for example 5 wt% or 10 wt%- of a glycol ethers, such as propylene glycol n-butyl ether;

[0140] -between 1 and 5 wt% of TNBT. TNBT is a good catalyst which enhances film formation;

[0141] -between 15 and 35 wt% of an alkane solvent, said alkanes having preferably 12 to 16 carbons.

[0142] Another preferred formulation of this mixture for the fourth aspect of the invention is given below. For this formulation excellent NALFA tests were observed. NALFA sets the industry standard for laminate flooring through rigorous, ANSI-accredited testing and certification.

[0143] -between 6 and 10 wt% -preferably between 7 and 9 wt%- of hydrophobic polymer, preferably hydrophobic polycarbodiimide and / or hydrophobic polyurethane;

[0144] -between 10 and 35 wt% -preferably between 22 and 27 wt%- of an alkyd resin; -between 5 and 23 wt% of an acetate co-solvent, such as 2-ethylhexylacetate;

[0145] -between 25 and 40 wt% of a glycol ether solvent, preferably dipropylene glycol dimethyl ether;

[0146] -between 1 and 5 wt% of an alcohol co-solvent, preferably an alcohol co-solvent with an ether group such as 3 -methoxy-3 -methyl -1 -butanol;

[0147] -optionally between 0,2 and 5 wt% of a catalyst, and preferably between 2 and 4 wt% of said catalyst, for example a titanate such as tetra-n-butyl titanate;

[0148] -optionally between 5 and 13 wt% of a hydrocarbon solvent.

[0149] Optionally a said mixture of the fourth aspect of the invention can comprise silica, such as (coated) fumed silica and this preferably in an amount of between 1 and 2 wt%, for example 1,5 wt%.

[0150] According to a variant of the first and / or second and / or third and / or fourth aspect of the invention, said panels do not comprise coupling parts and said panels are installed with an edge of a first one of said panels abutting an edge of a second one of said panels or at least being at a distance of at most 0,2 mm, preferably at most 0,1 mm of said edge of said second one of said panels, wherein one of said edges and preferably both of said edges have been treated with said waterproof coating and / or mixture. For this variant, the said coupling parts are not present. The embodiments described for the methods according to the invention described above apply mutatis mutandis for this variant.

[0151] The invention, according to a fifth aspect of the invention, also relates to a waterproof coating for treating edges of panels, wherein said waterproof coating at least comprises the following

[0152] -a binder, such as resin, a polyurethane or an acrylate;

[0153] -a solvent or water;

[0154] -preferably pigments and / or dyes;

[0155] -a crosslinker.

[0156] Preferably this waterproof coating is a waterproof coating as described in the first and / or second aspect of the invention. All the advantages described for the waterproof coating used in the first and / or second aspect of the invention and the preferred / specific embodiment therefore also apply mutatis mutandis for the waterproof coating of the fifth aspect of the invention and vice versa.

[0157] Preferably said waterproof coating is at least a two-component system, wherein a first component comprises at least said binder and a solvent or water, preferably comprises at least said binder and water, and wherein a second component comprises said crosslinker. Said pigments / dyes can be part of the first or second component, but can also be a separate component. Preferably said components are only added to each other at most 24h, preferably at most 12h or at most 6h, before said waterproof coating is used, for example is used to cover edges of panels. Said second component comprising said crosslinker can be the first composition of the first aspect of the invention.

[0158] Preferably said binder comprises or is an acrylate, such that the waterproof coating can be indicated as an acrylate dispersion, or said binder comprises or is polyurethane, such that the waterproof coating can be indicated as a polyurethane dispersion. It is especially which such coatings that said crosslinker significantly enhance the watertightness of a said applied coating.

[0159] Said crosslinker can be chosen from the list of: isocyanates, aziridines, oxazolidines, oxazoles, alkoxysilanes and carbodiimides. Of course, the waterproof coating can comprise a mixture of the above-mentioned crosslinkers. Preferably said waterproof coating only comprise one type of crosslinkers. The crosslinkers can for example consist of carbodiimide.

[0160] The waterproof coating preferably comprises between 0,3 and 10 wt% of crosslinkers, this preferably based on the total weight of the waterproof coating, more preferably between 0,5 and 8 wt%, for example 3 wt% or 5 wt%.

[0161] Said waterproof coating is preferably water-based. Further the waterproof coating can comprise wetting agents and / or wax and / or metallic soaps.

[0162] A preferred composition of the waterproof coating can be:

[0163] -between 25 and 70 wt% of a binder, such as an alkyd resin, a polyurethane or an acrylate or mixtures thereof;

[0164] -between 1 and 10 wt% of pigments and / or dyes;

[0165] -between 0,5 and 10 wt% of a crosslinker, for example between 1 and 3 wt%;

[0166] -between 2 and 5 wt% of a metallic soap;

[0167] -between 1 and 7 wt% of wax;

[0168] -between 1 and 3 wt% of a wetting agent;

[0169] -water.

[0170] According to a sixth aspect, the invention relates to a mixture for treating edges of panels, wherein said mixture is a solvent-based mixture comprising hydrophobic components, wherein the solvent-based mixture further comprises carbon in the form of graphene, carbon black, carbon nanotubes or activated carbon, and wherein preferably the dry matter of said mixture comprises between 0.1 wt% and 2 wt% of said carbon.

[0171] Said mixture according to the sixth aspect of the invention is preferably a mixture as described in the first and / or second and / or third and / or fourth aspect of the invention. Specific / preferred embodiments of mixtures of the first and / or second and / or third and / or fourth aspect of the invention apply mutatis mutandis for this mixture according to the sixth aspect of the invention and vice versa.

[0172] Said carbon will improve the water resistant properties of said mixture while also providing said mixture with additional darkening properties. Said darkening properties enable said mixture to darken an edge upon which the mixture is applied. This can be beneficial if a said edge has parts which are preferably covered. For example a said mixture comprising said carbon is very suitable for application upon a lowered edge, for example in the form of a chamfer or a bevel, of a panel comprising a substrate and a top layer, wherein said lowered edge extends from the top layer into the substrate. Such a top layer can comprise a white / yellow paper with a decor printed upon it. With such a mixture, the white line formed by said paper can be covered. It has been found that carbon black is very suitable to cover up such white lines. Further carbon black contributes to the watertightness of the edge comprising said cured mixture. Also with carbon black, mixtures having a good shelf life can be made. Graphene contributes to the watertightness of the edge comprising said cured mixture, since graphene forms a maze through which water cannot easily move. Activated carbon enhances the water-repellent properties of the mixture.

[0173] Preferably the mixture is a solvent-based mixture. Said carbon is preferably dissolved in a solvent and added in this form to form a said mixture. With the aid of solvents, curing can be performed smoothly. The mixture can comprise a solvent with a flashpoint of at least 60 °C, preferably at least 80°C, for example at least 100°C, for example at least 120°C and / or wherein preferably the mixture is VOC free or comprises at most 1 percent by weight of VOC’ s.

[0174] In a specific embodiment the mixture comprises wetting agents, wherein preferably the dry matter of said mixture comprises between 0.1 wt% and 5 wt% of said wetting agents, preferably between 2 and 4 wt%.

[0175] In a very preferred embodiment the mixture comprises a dye, preferably a metalcomplex dye such as a chrome-complex dye. According to a variant said mixture does not comprise a said carbon, but comprises a metal-complex dye, such as chrome-complex dye. The benefit of such a metal-complex dye is that there is less risk of settling.

[0176] The invention, according to a seventh aspect of the invention, also relates to a panel comprising profiled edges with coupling parts which allow such panels to be coupled to each other, wherein said panel comprises a first edge with a first coupling part, preferably a female coupling part, and a second edge with a second coupling part, preferably a male coupling part, said first coupling part of a said panel and said second coupling part of another said panel being couplable as such to couple such panels to each other, wherein said panel is manufactured according to a method of the first and / or second and / or third and / or fourth aspect of the invention. Said coupling parts can be coupling parts which allow coupling by angling, by horizontal movement and / or a downward movement. Said coupling parts can be as described in WO 2020 / 109961, WO 2021 / 070022, WO 2021 / 111210, WO 2022 / 097052 and WO 2023 / 119043. Coupling parts of said patent applications are incorporated by reference.

[0177] According to all aspects of the invention, the panels are preferably panels comprising at least a substrate and a top layer. The substrate is preferably selected from or the substrate preferably comprises:

[0178] - a wood fibre board, for example an MDF (Medium Density Fibreboard) or HDF (High Density Fibreboard) board. Such a panel can be indicated as a laminate;

[0179] - a particle board, or

[0180] - a mineral board, for example a magnesium oxide board, a plasterboard, a board made of mineral fibres bonded with a binder (for example by means of a thermosetting binder), or a fibre-cement board, or

[0181] - a polymer-based substrate, for example such as a filled or unfilled and / or foamed polyvinyl chloride-based substrate or a substrate based on some other thermoplastic or thermosetting polymer. Such a panel can be an SPC (solid plastic composite) panel or an LVT (luxury vinyl tile) panel or a WPC (waterproof plastic composite) panel.

[0182] If the substrate is an MDF or HDF, it preferably has a swelling rate between 2 and 20%, as measured according to EN 317: 1993. Even for low quality MDF or HDF, being MDF or HDF having a swelling of at least 10% or at least 15% as measured according to EN 317: 1993, good watertight properties can be obtained by applying a said waterproof coating and / or mixture to the at least part of a said edge. The swelling is measured by submerging the substrate in water having for example a pH of 7 and a temperature of 20°C. According to all aspects of the invention, said first and second coupling parts could be produced substantially in the form of a groove and tongue, which in the coupled state provide locking in the direction perpendicular to the plane of the coupled panels, wherein the groove and tongue are provided with locking elements, which in the coupled state of two such panels provide locking in the direction in the plane of the panels and perpendicular to the coupled edges, wherein the groove is delimited by an upper lip and a lower lip, preferably wherein the lower lip projects farther in the distal direction than the upper lip, wherein the lower lip comprises a locking element in the form of an upwards directed locking element for interacting with a locking element on the underside of the tongue for forming locking in the direction in the plane of the panels and perpendicular to the coupled edges. The panels are then preferably coupled to each other by means of a turning motion and / or by pushing the panels together with a snap effect substantially parallel to the plane of the panels. If pretension is present, said lower lip is preferably arranged to deflect so as to be bent- out and push on said tongue to urge the coupled panels towards each other. For example the aforementioned lower lip in a coupled state could display a maximum deflection of at least 0.07 millimeter.

[0183] For better illustration of the features of the invention, some preferred embodiments are described hereunder, as examples without any limiting character, referring to the appended drawings, in which:

[0184] Fig. 1 shows a floor panel obtained by a method according to the first and / or second and / or third and / or fourth aspect of the invention;

[0185] Fig. 2 shows a first possible embodiment of this floor panel in a cross-section along line II-II in Fig. 1;

[0186] Fig. 3 shows a second possible embodiment of this floor panel in a crosssection along line II-II in Fig. 1;

[0187] Fig. 4 shows a third possible embodiment of coupled floor panels obtained by a method according to the first and / or second and / or third and / or fourth aspect of the invention in a cross-section; Fig. 5 shows a possible embodiment of this floor panel in a cross-section along line V-V in Fig. 1;

[0188] Fig. 6 illustrates detail F6 of figure 2;

[0189] Fig. 7 illustrates detail F7 of figure 3;

[0190] Fig. 8 schematically shows a method according to the first aspect of the invention;

[0191] Fig. 9 shows a floor covering comprising floor panels obtained by a method according to the first and / or second and / or third and / or fourth aspect of the invention.

[0192] Fig. 10 shows a possible embodiment of coupled floor panels shown in figure 9 in a cross-section along line X-X in Fig. 9.

[0193] Fig. 1 shows an elongated rectangular floor panel 1 that is provided with coupling parts on two pairs of opposite edges 2-3 (the long edges) and 4-5 (the short edges). Said long edges 2-3 comprise a first long edge 3 with a female coupling part, and a second long edge 2 with a male coupling part, which allow the panel 1 to be coupled on its second long edge 2 to the first long edge 3 of another such panel 1. Said short edges 4-5 comprise a first short edge 5 with a female coupling part, and a second short edge 4 with a male coupling part, which allow the panel 1 to be coupled on its second short edge 4 to the first short edge 5 of another such panel 1.

[0194] The panel 1 comprises, from top to bottom: a top layer 8, a substrate 12, an optionally a balancing layer (not shown in the figures). This top layer 8, as shown in figures 2 to 7, comprises a decorative layer 10, being preferably a resin impregnated printed paper, and a wear layer 11, being preferably a resin impregnated translucent paper with optionally hard particles such as aluminium oxide. The balancing layer, if present, is preferably a resin impregnated kraft paper. The substrate 12 is preferably MDF or HDF, with for example a swelling rate of 2%, 4%, 6%, 8%, 10%, 12% or 15% measured according to EN 317: 1993. Of course, other embodiments are possible. Such a floor panel 1 is typically named a laminate floor panel 1. Of course, other embodiments -not shown- are possible, wherein the substrate 12 is for example a thermoplastic based substrate and the panel is an SPC panel or a WPC panel, or wherein the top layer comprises a veneer or a thicker timber layer or wherein the top layer comprises a print directly printed upon the substrate.

[0195] Fig. 2 shows the floor panel 1 from Fig. 1 in a cross-section along line II-II in Fig. 1, and illustrates that the coupling parts form a first locking system on the long edges 2-3, which provides locking in the plane of the panels 1 and perpendicular to the long edges 2-3, namely locking in the horizontal direction H; and a second locking system that produces locking perpendicular to the plane of the panels 1, namely locking in the vertical direction V. The coupling parts illustrated in this example are mainly formed by a tongue 6 and a groove 7. The groove 7 is delimited by an upper lip and a lower lip 9, wherein the lower lip 9 projects farther in the distal direction than the upper lip.

[0196] The coupling parts as shown in figures 2 to 4, are of the type that allows two such panels 1 to be coupled together selectively by means of a turning motion and / or by means of a horizontal sliding movement of one such panel 1 relative to another such panel 1. In the examples, the coupling parts are produced in the substrate 12.

[0197] Preferably the coupling parts on the first pair of opposite edges 2-3 are configured as overlapping, so that during coupling on the first pair of opposite edges 2-3, coupling with pretension is obtained. As a result, in the coupled state, upper parts of the long edges 2-3 of the coupled panels 1 are pushed together. This can be obtained because in the coupled state the lower lip 9 is slightly bent elastically. This elastic bending gives rise to a compressive force that presses the long edges 2-3 against each other.

[0198] Preferably the pair of opposite short edges 4-5 is provided with coupling parts that comprise locking elements so that in the coupled state, locking occurs in the direction V perpendicular to the surface of the coupled panels 1 and locking also occurs in the direction H in the plane of the coupled panels 1 and perpendicular to the coupled edges 4-5. The coupling parts can be configured as the coupling parts of the long edges 2-3, but can also be configured differently. In figure 5, a configuration which differs from the long edges 2-3 is shown for the short edges 4-5. Here the short edges 4-5 are couplable to each other by a downward movement.

[0199] The present invention is by no means limited to coupling parts of the embodiments described above.

[0200] Preferably, the panels 1 shown in figures 1 to 5 are at least according to the first aspect of the invention and preferably according to the first and the second aspect of the invention.

[0201] The panel 1 shown in the embodiments of figure 3, can be obtained by a method shown in figure 8 and comprising the successive steps of:

[0202] -forming the coupling parts, with the panel 1 shown in figure 8 already comprising said coupling parts;

[0203] -applying a waterproof coating 14 on a portion of each of the long edges 2-3, and this with the aid of an application device, here a spraying device 16. The waterproof coating 14 is applied on the lowered edge 17 (see further) and partly on the sealing face 18 (see further) which is directly located below said lowered edge 17. Of course other application devices, such as transfer wheels or vacumates, are possible. Said waterproof coating 14 can be present in a barrel 15 or the like and from this barrel 15 delivered to the spraying device 16. Said waterproof coating 14 is preferably formed by bringing a lacquer, a first composition and possible other additives such as wax and / or wetting agents and / or hydrophobic components together and stirring. Applying said waterproof coating 14 is preferably done while the panel 1 is being transported by a transporting device, such as a chain transporting device 20.

[0204] -drying this waterproof coating 14, and this for example with the aid of IR lamps.

[0205] Optionally, before or after applying said waterproof coating 14, a mixture comprising hydrophobic components and preferably carbon in the form of carbon black, graphene, carbon nanotubes or activated carbon is applied on a portion of each of the long edges 2-3, and this with the aid of an application device. Here said portions of the long edges 2-3 then preferably comprises both the waterproof coating 14 and said hydrophobic components of the mixture. During the successive steps of applying said waterproof coating 14 and drying of said waterproof coating 14, the panel 1 is preferably moved by a chain transporting device 20 according to the direction as indicated by the arrow in figure 8.

[0206] Figure 8 shows an embodiment to apply said waterproof coating 14. Said mixture can be applied in a similar manner, e.g. also with an application device while the panel 1 is being transported.

[0207] Said method shown in figure 8 can also be the method for the embodiments shown in figures 2 and 4, except for the location upon which the waterproof coating 14 is applied.

[0208] The waterproof coating 14 forms a film 13 upon said portion upon which said waterproof coating 14 is applied. This film 13 is indicated by a bold line. The film 13 is preferably a thin film 13 which is preferably smaller than 50 micrometer, more preferably smaller than 25 micrometer.

[0209] The long edges 2-3 shown in the embodiment shown in figure 2 do not comprise a lowered edge 17. The long edges 2-3 shown in the embodiment of figure 3 comprise lowered edges 17. The long edges 2-3 shown in the embodiment of figure 4 form a recess 19 in coupled condition. The short edges 4-5 shown in the embodiment of figure 4 comprise lowered edges 17. All said edges 2-3-4-5 have sealing faces 18 which are provided to contact each other, and which form a first barrier for water. When said lowered edges 17 are present, said sealing faces 18 are preferably directly located beneath said lowered edges 17. As shown in figure 2, the sealing faces 18 form the most upper part of said long edges 2-3. The film 13 formed by said waterproof coating 14 forms a barrier for water. As shown in figure 3, the lowered edge 17 extends from the surface of the top layer 8 into the substrate 12. Said film 13 is applied upon at least said lowered edges 17, but preferably -and as shown in figure 7- also on said sealing faces 18 which are present directly under said lowered edges 17. For the embodiment shown in figure 4, the recess 19 extends from the top layer 8 into the substate 12 and is limited at its sides by the most upper part of the first long edge 3 and the most upper part of the second long edge 2, and at its bottom by the substrate 12 located above the tongue 6. The film 13 covers the entire recess 19 and optionally the sealing faces 18 located below the recess 19.

[0210] Figures 9 and 10 show other embodiments of floor panels 1 according to the invention. The floor covering shown in figure 10 comprises a plurality of floor panels 1. These floor panels 1 can be thin, can have a thickness of less than 4 mm or even less than 3 mm, for example can be 2,5 mm. Such thin floor panels 1 can also be indicated as floor strips. Said floor panels 1 comprise a substrate 12 and a provided thereon decorative top layer 8, wherein said floor panels 1 comprise profiled long edges 2-3 with male and female coupling parts 60, 70 and profiled short edges 4-5. As can be seen in figure 11, said first long edge 3 comprises a bottom lip 70 and said second long edge 2 comprises a top lip 60. In coupled condition, said top lip 60 of the panel 1 vertically overlaps said bottom lip 70 of another said panel 1. A recess 19 in said floor covering is formed by a first upstanding surface 22, said first upstanding surface 22 preferably being a generally vertically extending surface 22, and a second upstanding surface 23, said second upstanding surface 23 preferably being a generally vertically extending surface 23, and a bottom portion 24 connecting said first and second upstanding surfaces 22-23, wherein said first upstanding surface 22 is formed by a distal portion of said top lip 60, said second upstanding surface 23 is formed by the most upper portion of the profiled edge at said first long edge 3. Said recess 19 is covered by a film 13 formed by applying a waterproof coating 14. Preferably as shown in figure 10, the waterproof coating 14 is applied upon the upper surface of the bottom lip 70 to at least cover said bottom portion 24 of the recess 19 and also the part of the upper surface of the bottom lip located next to this bottom portion 24 and under the top lip 60. The ensures the watertightness. Preferably, and as shown in figure 10, the bottom lip 70 contacts the profiled edge at said second long edge 2 at abutting surfaces 24-25. For the floor covering shown in figure 9, said floor panels 1 are preferably floor strips of so-called gluedown LVT, dryback LVT or looselay LVT (luxury vinyl tile). In figure 10 a glue layer 21 is shown to connect said floor strips 1 to an underground 26. For example the substrate 12 comprises at least polyvinylchloride, or another thermoplastic, and fillers, for example at least 50 wt% of fillers. Said substrate 12 can comprise plasticizers, preferably at least 15 phr of plasticizers, and / or in that said substrate 12 comprises soft or semi-rigid PVC. Said top layer 8 can be essentially made from polyvinylchloride (PVC) or another thermoplastic, for example a decorative layer 10 which is a print layer formed by a printed PVC foil and a provided thereon wear layer 11 of PVC, preferably soft PVC, and preferably further a lacquer layer provided on said wear layer 11, for example an acrylic or urethane lacquer layer and / or a UV and / or excimer cured lacquer layer.

[0211] For all the embodiments above, if also a said mixture according to the invention is applied -or only a said mixture is applied-, then said mixture is preferably applied at the location of said film 13.

[0212] Here below some examples of possible compositions of the waterproof coating 14 according to the fifth aspect of the invention and used in the first aspect of the invention are given. Here below some possible composition of the mixture according to the sixth aspect of the invention and used in the third aspect of the invention are given. Here below also some example for the second aspect of the invention are shown. Also comparative test results are discussed.

[0213] Test 1:

[0214] Laminate floor panels 1 comprising an HDF substrate 12, and coupling parts in the form of tongue 6 and grooves 7 and lowered edges 17 as shown in figure 3, were treated with a waterproof coating 14 according to the invention. In order to determine the water-resistant properties of said laminate floor panels 1 the swelling at the edges was determined. To have a reference said laminate floor panels 1 were also treated with a reference lacquer.

[0215] Edges of said laminate panels 1, and at least said lowered edges 17, were treated with a waterproof coating 14 according to the invention. To test the water-resistant properties, a test set-up according to the Nalfa surface swell test was used. For the Nalfa surface swell test, a cylinder with water is placed on the T-joint of a floor covering comprising said laminate floor panels 1 and this for 24h. Then the floor covering is dried for another 24h. Afterwards the swelling of the material is measured by a measurement device.

[0216] To measure the thickness use was made of a thickness gauge (Kafer FD50). Measurements were taken at different places along the length of the edges.

[0217] The applied waterproof coating 14 was made by adding 5g of dry matter weight of a crosslinker to 100 g of a first lacquer. Said first lacquer is a water-based lacquer comprising a mixture of acrylates and polyurethanes. The crosslinker is a solventbased crosslinking agent based on an aziridinic structure and having an aliphatic nature.

[0218] The reference lacquer is said first lacquer as such.

[0219] Test 2:

[0220] Laminate floor panels 1 comprising an HDF substrate 12, and coupling parts in the form of tongue 6 and grooves 7 and lowered edges 17 as shown in figure 3, were treated with waterproof coatings 14 according to the invention and a mixture comprising hydrophobic components, said mixture being different from the waterproof coating 14. In order to determine the water-resistant properties of said laminate floor panels 1 the swelling at the edges was determined.

[0221] Edges of said laminate panels 1, and at least said lowered edges 17, were treated with a waterproof coating 14 according to the invention and a mixture comprising hydrophobic components. To test the water-resistant properties, a test set-up according to the Nalfa surface swell test was used. For the Nalfa surface swell test, a cylinder with water is placed on the T-joint of a floor covering comprising said laminate floor panels 1 and this for 24h. Then the floor covering is dried for another 24h. Afterwards the swelling of the material is measured by a measurement device.

[0222] To measure the thickness use was made of a thickness gauge (Kafer FD50). Measurements were taken at different places along the length of the edges.

[0223] The applied waterproof coating 14 was made by adding 5g of dry matter weight crosslinker to 100 g of a first lacquer. Said first lacquer is a water-based lacquer comprising a mixture of acrylates and polyurethanes. The crosslinker for the waterproof coating 14 was the following:

[0224] -waterproof coating A: water-based polycarbodiimide crosslinker

[0225] -waterproof coating B: a solvent-base crosslinking agent based on an aziridinic structure and having an aliphatic nature.

[0226] The mixture had the following composition: 30 wt% of hydrophobic polyurethane, 37 wt% of solvent comprising hydrocarbons with 11 to 14 carbons, 5 wt% of cosolvent 2-ethylhexylacetate, 25 wt% of a long-oil alkyd resin, 3 wt% of 2- ethylhexyl titanate (or alternatively TNBT).

[0227] The reference lacquer is said first lacquer as such.

[0228] Test 3

[0229] Laminate floor panels 1 comprising an HDF substrate 12, and coupling parts in the form of tongue 6 and grooves 7 and lowered edges 17 as shown in figure 3, were treated with a waterproof coating 14 according to the second aspect of the invention.

[0230] In order to determine the water-resistant properties of said laminate floor panels 1 the contact angle at the edges was determined. To have a reference said laminate floor panels 1 were also treated with a reference lacquer. Edges of said laminate panels 1, and at least said lowered edges 17, were treated with a waterproof coating 14 according to the invention. To test the water-resistant properties, a droplet of water was dropped upon said lowered edges 17 and the contact angle was measured. The applied waterproof coating 14 was made by adding a first composition to a first lacquer. Said first lacquer is a water-based lacquer comprising a mixture of acrylates and polyurethanes.

[0231] The reference lacquer is said first lacquer as such.

[0232] An increase of the contact angle was detected when adding a specific first composition to the reference first lacquer.

[0233] Test 4

[0234] Laminate floor panels 1 comprising an HDF substrate 12, and coupling parts in the form of tongue 6 and groove 7 as shown in figure 2, were treated with a waterproof coating 14 according to the invention. In order to determine the water-resistant properties of said laminate floor panels 1 the contact angle at the edges was determined. To have a reference said laminate floor panels 1 were also treated with a reference lacquer.

[0235] Edges of said laminate panels 1, and at least said lowered edges 17, were treated with a waterproof coating 14 according to the invention. To test the water-resistant properties, a droplet of water was dropped upon said lowered edges 17 and the contact angle was measured.

[0236] The applied waterproof coating 14 was made by adding a first composition to a first lacquer. Said first lacquer is a water-based acrylate lacquer.

[0237] The reference lacquer is said first lacquer as such.

[0238] An increase of the contact angle was detected when adding a specific first composition to the reference first lacquer.

Claims

Claims:1.- A method for manufacturing a set of panels, wherein said panels (1) comprise profiled edges with coupling parts which allow the panels (1) from the set to be coupled to each other, wherein said panels (1) comprise a first edge (3) with a first coupling part, preferably a female coupling part, and a second edge (2) with a second coupling part, preferably a male coupling part, said first coupling part of a first one of said panels (1) and said second coupling part of a second one of said panels (1) being couplable as such to couple said first one of said panels (1) and said second one of said panels (1) to each other, wherein the method comprises the step of forming the coupling parts, characterized in that the method further comprises at least the following step:-applying a waterproof coating (14) on at least a part of the first edge (3), and preferably also on at least a part of the second edge (2); wherein the waterproof coating (14) is obtained by adding a first composition comprising a crosslinker to a lacquer, wherein the weight ratio of the dry matter weight crosslinkers upon the total weight of the lacquer is preferably between 3 : 1000 and 1 : 10, more preferably between 5: 1000 and 1 :20.2.- The method according to claim 1, wherein said lacquer is a water-based lacquer.3.- The method according to claim 1 or 2, wherein the lacquer is a dispersion comprising an acrylate, a polyurethane, an alkyd resin or mixtures thereof.4.- The method according to any of the preceding claims, wherein the crosslinker is chosen from the list of: isocyanates, aziridines, oxazolidines, oxazoles, carbodiimides and alkoxysilanes.5.- The method according to any of the preceding claims, wherein adding the first composition to the lacquer takes place at most 24h before applying said waterproof coating (14), preferably at most 12h, most preferably at most 6h.6.- The method according to any of the preceding claims, where the dry matter of the first composition substantially comprises said crosslinker.7.- The method according to any of the preceding claims, wherein the first composition is solvent based.8.- The method according to any of the preceding claims, wherein the panels(1) comprise a substrate (12) and a top layer (8), and wherein the first edge (3), and preferably also the second edge (2), comprises a lowered edge (17) which extends from the top layer (8) and preferably into the substrate (12), for example in the form of a chamfer or bevel, wherein the waterproof coating (14) is at least applied upon said lowered edge (17) and wherein the waterproof coating (14) preferably forms a decoration separate from the top layer (8).9.- The method according to any of the preceding claims, wherein the waterproof coating (14) comprises pigments and / or dyes.

10. The method according to any of the preceding claims, wherein the first composition comprises hydrophobic components or hydrophobic components are added, before, during or after adding the first composition to the lacquer, to the lacquer.

11. The method according to any of the preceding claims, wherein a mixture comprising hydrophobic components is applied on at least a part of the first edge (3), and preferably also on at least a part of the second edge (2), wherein said mixture is different from said waterproof coating (14), such that at least a portion of the first edge (3), and preferably also a portion of the second edge (2), comprises both the waterproof coating (14) and said hydrophobic components of the mixture.12.- The method according to any of the preceding claims, wherein said first composition further comprises wax or wherein the waterproof coating (14) is obtained by adding said first composition and wax to the lacquer.13.- The method according to any of the preceding claims, wherein said first composition further comprises wetting agents or wherein the waterproof coating (14) is obtained by adding said first composition and wetting agents to the lacquer.14.- The method according to any of the preceding claims, wherein said first composition comprises a non-VOC coalescing agent.15.- The method according to any of the preceding claims, wherein the waterproof coating (14) forms a film (13) of less than 50 micrometer, preferably less than 25 micrometer.16.- A method for manufacturing a set of panels, optionally according to any of the preceding claims, wherein said panels (1) comprise profiled edges with coupling parts which allow the panels (1) from the set to be coupled to each other, wherein said panels (1) comprise a first edge (3) with a first coupling part, preferably a female coupling part, and a second edge (2) with a second coupling part, preferably a male coupling part, said first coupling part of a first one of said panels (1) and said second coupling part of a second one of said panels (1) being couplable as such to couple said first one of said panels (1) and said second one of said panels (1) to each other, wherein the method comprises the step of forming the coupling parts, characterized in that the method further comprises at least the following step: -applying a waterproof coating (14) on at least a part of the first edge (3), and preferably also on at least a part of the second edge (2); wherein the waterproof coating (14) is obtained by adding a first composition to a lacquer, said first composition comprising one or more of: poly siloxane, silicone, silane, fumed silica, metal soap, metal drier, metal carboxylate, or wax, wherein the weight ratio of the dry matter weight of said polysiloxane, silicone, fumed silica, metal soap, metal drier, metal carboxylate or wax of the first composition upon thetotal weight of the lacquer is preferably between 1 : 1000 and 1 : 10, more preferably between 1 :500 and 6: 100, most preferably between 1 : 100 and 5: 100.17.- The method according to claim 16, wherein said lacquer is a water-based lacquer.18.- The method according to claim 16 or 17, wherein the lacquer is a dispersion comprising an acrylate, a polyurethane, an alkyd resin or mixtures thereof.19.- The method according to any of the preceding claims 16 to 18, wherein said first composition at least comprises silicone and / or polysiloxane, and preferably also comprises a wax.20.- The method according to any of the preceding claims 16 to 19, wherein adding the first composition to the lacquer takes place at most 24h before applying said waterproof coating (14), preferably at most 12h, most preferably at most 6h.21.- The method according to any of the preceding claims 16 to 20, wherein the first composition is water-based, and is preferably a water-based emulsion.22.- The method according to any of the preceding claims 16 to 21, wherein the panels (1) comprise a substrate (12) and a top layer (8), and wherein the first edge (3), and preferably also the second edge (2), comprises a lowered edge (17) which extends from the top layer (8) and preferably into the substrate (12), for example in the form of a chamfer or bevel, wherein the waterproof coating (14) is at least applied upon said lowered edge (17) and wherein the waterproof coating (14) preferably forms a decoration separate from the top layer (8).23.- The method according to any of the preceding claims 16 to 22, wherein the waterproof coating (14) comprises pigments and / or dyes.

24. The method according to any of the preceding claims 16 to 23, wherein a mixture comprising hydrophobic components is applied on at least a part of the first edge (3), and preferably also on at least a part of the second edge (2), wherein said mixture is different from said waterproof coating (14), such that at least a portion of the first edge (3), and preferably also a portion of the second edge (2), comprises both the waterproof coating (14) and said hydrophobic components of the mixture.25.- The method according to any of the preceding claims 16 to 24, wherein said first composition further comprises wetting agents or wherein the waterproof coating (14) is obtained by adding said first composition and wetting agents to the lacquer.26.- The method according to any of the preceding claims 16 to 25, wherein the waterproof coating (14) forms a film (13) of less than 50 micrometer, preferably less than 25 micrometer.

27. A method for manufacturing a set of panels, optionally according to any of the preceding claims, wherein said panels (1) comprise profiled edges with coupling parts which allow the panels (1) from the set to be coupled to each other, wherein said panels (1) comprises a first edge (3) with a first coupling part, preferably a female coupling part, and a second edge (2) with a second coupling part, preferably a male coupling part, said first coupling part of a first one of said panels (1) and said second coupling part of a second one of said panels (1) being couplable as such to couple said first one of said panels (1) and said second one of said panels (1) to each other, wherein the method comprises the step of forming the coupling parts, and at least the following further step:-applying a mixture comprising hydrophobic components on at least a part of the first edge (3), and preferably also on at least a part of the second edge (2); characterized in that the mixture comprises carbon in the form of graphene, carbon black, carbon nanotubes, or activated carbon, and wherein preferably the dry matter of said mixture comprises between 0.1 wt% and 2 wt% of said carbon.

28. A method for manufacturing a set of panels, optionally according to any of the preceding claims, wherein said panels (1) comprise profiled edges with coupling parts which allow the panels (1) from the set to be coupled to each other, wherein said panels (1) comprises a first edge (3) with a first coupling part, preferably a female coupling part, and a second edge (2) with a second coupling part, preferably a male coupling part, said first coupling part of a first one of said panels (1) and said second coupling part of a second one of said panels (1) being couplable as such to couple said first one of said panels (1) and said second one of said panels (1) to each other, wherein the method comprises the step of forming the coupling parts, and at least the following further step:-applying a mixture on at least a part of the first edge (3), and preferably also on at least a part of the second edge (2); characterized in that said mixture comprises a hydrophobic polymer, such as a polycarbodiimide, a titanate -such as tetra n-butyl titanate-, and one or more solvents.

29. The method according to claim 28, wherein the solvents comprise alkanes having preferably 12 to 16 carbons and one or more co-solvents chosen from the list of: hydrophobic glycol ethers - such as propylene glycol n-butyl ether-, dipolar aprotic solvents -such as l-butylpyrrolidin-2-one-.

30. A waterproof coating for treating edges of panels, wherein said waterproof coating (14) at least comprises the following:-a binder, such as resin, a polyurethane and / or an acrylate;-a solvent or water;-a crosslinker;-preferably pigments and / or dyes.

31. The waterproof coating according to claim 30, wherein said binder comprises an acrylate and the waterproof coating (14) is an acrylate dispersion, or said binder comprises polyurethane and the waterproof coating (14) is a polyurethane dispersion.

32. The waterproof coating according to claim 30 or 31, wherein-the crosslinker is chosen from the list of: isocyanates, aziridines, oxazolidines, oxazoles, carbodiimides and alkoxysilanes; and / or-the waterproof coating (14) comprises between 0,3 and 10 wt% of crosslinker, preferably between 0,5 and 8 wt% of crosslinker.

33. The waterproof coating according to any of claims 30 to 32, wherein the waterproof coating (14) comprises wetting agents and / or wax and / or metallic soaps.

34. A mixture for treating edges of panels, wherein said mixture is a solvent-based mixture comprising hydrophobic components, characterized in that the solvent-based mixture further comprises carbon in the form of graphene, carbon black or activated carbon, and wherein preferably the dry matter of said mixture comprises between 0.1 wt% and 2 wt% of said carbon.

35. The mixture according to claim 34, wherein the mixture comprises wetting agents, wherein preferably the dry matter of said mixture comprises between 0.1 wt% and 5 wt% of said wetting agents.

36. The mixture according to claim 34 or 35, wherein the mixture comprises a dye, preferably a metal-complex dye such as a chrome-complex dye.

37. A panel comprising profiled edges with coupling parts which allow such panels (1) to be coupled to each other, wherein said panel (1) comprises a first edge (3) with a first coupling part, preferably a female coupling part, and a second edge (2) with a second coupling part, preferably a male coupling part, said first coupling part of a said panel (1) and said second coupling part of another said panel (1) being couplable as such to couple such panels (1) to each other, characterized in that said panel (1) is manufactured according to any of the preceding claims 1 to 29.

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