Wood material panel with coated and sealed square and / or bevelled edges

Abstract

The present invention relates to a composition for sealing and coating square and / or bevelled edges of wood material panels, comprising at least one swelling agent, and at least one additive composed of at least one compound of general formula (I) R1 aSiX1 (4-a) (I), wherein X1 is alkoxy, aryloxy, acyloxy, and R1 is an organic moiety selected from the group comprising alkyl, aryl, cycloalkyl, which can be interrupted by -O- or -NH-, and wherein R1 comprises at least one functional group Q1, which is selected from a group containing an acryl group, an acryloxy group, a methacryl group, a methacryloxy group, a cyano group, an isocyano group and an epoxide group, and a is 0, 1, 2, 3, in particular is 0 or 1, at least one compound of general formula (II) R2 bSiX2 (4-b) (II), wherein X2 is alkoxy, aryloxy, acyloxy, R2 is a non-hydrolyzable organic moiety R2 selected from the group comprising alkyl and aryl, and b is 1, 2, 3, or 4, and at least one aqueous polymer dispersion, and at least one surfactant.

Description

[0001] Wood-based panel with coated and sealed edges and / or bevels

[0002] The present invention relates to a wood-based panel with coated and sealed edges and / or bevels, wherein the composition used for coating and sealing the edges and / or bevels of the wood-based panel comprises silanes, swelling agents, and surfactants. The present invention also relates to the production of this composition.

[0003] Description

[0004] Floor panels with tongue-and-groove profiles on the side edges for installation in panel assemblies, such as laminate flooring, are widely used and conventionally known. The tongue-and-groove profiles enable easy installation of floor panels with floor coverings. Such floor coverings can be made of wood fiberboard or plastic panels, for example. The floor panels are usually provided with a decorative layer and an abrasion-resistant surface layer.

[0005] Such tongue-and-groove profiles have a tongue (or tongue) on a first side edge with a (first) joining surface provided above the tongue, and a groove with a lip and a (second) joining surface on a second side edge. When installing the panels, the tongue and groove are inserted or clicked into each other, resulting in contact between the first and second joining surfaces. However, this approach creates a gap on the upper side of the joined panels, particularly at the contact points of the joining surfaces of the two opposite side edges of two joined floor panels, through which moisture and dirt can penetrate between the floor panels.

[0006] To reduce water penetration at the contact points of the tongue-and-groove profiles, modern click profiles also feature a rebate in the area of ​​the joining edge. A rebate is defined as a ledge, edge, or fold.

[0007] Laminate floors with so-called V-joints have proven very popular. These V-joints are created when floorboards with bevels are installed. The bevels are angled milled cuts on the side edges of the floorboards, which are painted with colored varnishes and give the laminate flooring a visual impression similar to parquet. However, all of these panel connection variants still offer inadequate protection against water penetration at the connection or contact point. This is due to the fact that with these products, water is sucked into the profile area via capillary action through the fine joints or gaps between the floorboards (e.g. during cleaning), causing swelling there. To examine this problem, the so-called NALFA test was developed. In this test, a defined amount of water is applied to the connection area of ​​three installed plank sections.After a defined test time (24 hours), an analysis is carried out to determine whether water is still present on the surface, whether water has penetrated into the profile, whether water has penetrated through the profile to the underside, and whether there is any clearly visible swelling of the planks.

[0008] To mitigate moisture damage, various strategies have been used individually or in combination. The simplest way to prevent moisture penetration into the profile is to achieve the tightest possible fit in the tongue and groove joint. However, this can make it difficult to join the elements or cause damage during installation. This method also has the disadvantage that if water penetrates the tongue and groove area, the wood-based substrate will swell normally.

[0009] Another option is sealing the profile with hydrophobic agents. WO 2006 / 038867, for example, describes the use of waxes to coat the edges, with at least partial penetration of the wax into the wood-based material being observed. EP 903451 A2 describes the use of diphenylmethane diisocyanate to treat the edges, which readily penetrates the wood-based material. WO 2008 / 078181 A1, in turn, uses a fluorinated polymer, e.g., a perfluoroalkyl methacrylate copolymer, as the coating agent, with the layer-forming material being solid at room temperature.

[0010] The disadvantage of these known sealants is that they often migrate into the wood-based substrate during application, thus minimizing the water-repellent effect. However, this can also occur afterward, so that the effect is gradually lost during use. Furthermore, perfluoro compounds are considered critical from an environmental perspective. Accordingly, the known measures have various disadvantages. For example, the improvement in swelling protection is too small, the proposed measures cannot withstand real-world stresses, and the achieved effects are temporary.

[0011] The present invention was therefore based on the object of overcoming the aforementioned disadvantages. In particular, the technical object of the invention was to produce a laminate flooring based on wood-based panels that, by sealing the edges and bevels, creates a watertight profile.

[0012] This object is achieved according to the invention by a wood-based panel having the features of claim 1.

[0013] Accordingly, a wood-based panel, in particular floor panels, with coated and sealed edges and / or bevels is provided, wherein the composition used for coating and sealing the edges and / or bevels of the wood-based panels comprises the following: a) At least one swelling agent, and b) At least one additive comprising at least one compound of the general formula (I)

[0014] R 1 aSiX 1(4-a) (I), where

[0015] - X 1 Alkoxy, aryloxy, acyloxy, and

[0016] - R 1 an organic radical is selected from the group comprising alkyl, aryl, cycloalkyl, which may be interrupted by -O- or -NH-, and

[0017] - where R 1 has at least one functional group Qi selected from a group containing an acrylic, acryloxy, methacrylic, methacryloxy, cyano, isocyano and epoxy group, and

[0018] - a = 0, 1, 2, 3, in particular 0 or 1,

[0019] - at least one compound of the general formula (II) R 2 bSiX 2 (4-b) (II), where

[0020] - X 2 alkoxy, aryloxy, acyloxy,

[0021] - R 2 a non-hydrolyzable organic residue R 2 is selected from the group comprising alkyl and aryl, and

[0022] - b = 1, 2, 3, or 4, preferably 1 or 2, and

[0023] - at least one aqueous polymer dispersion, and c) at least one surfactant, preferably at least one anionic surfactant.

[0024] The water-repellent effect of the present composition can be realized for a variety of locking profiles. The present composition is applied in particular to profile surfaces, joining surfaces, and / or bevels of side edges of wood-based panels, especially floor panels.

[0025] By adding a swelling agent, this composition not only exhibits a water-repellent effect but also seals the joints of floor panels laid together to form a floating floor covering. This further improves the tightness of the joints between the joined panels.

[0026] The additive used in the present composition comprises a crosslinking component, the compound of general formula (I), and a hydrophobic component, the compound of general formula (II). The crosslinking, hydrophilic component of formula (I) enables, on the one hand, a bonding of the compound to the wood fibers, particularly via the free -OH groups (present or formed by hydrolysis of, for example, alkoxy groups), and, on the other hand, the formation of a network. The hydrophobic component of formula (II) - formed, for example, from the alkyl groups of the radical R 2 - forms a water-repellent barrier. This prevents water from diffusing through the network of the formed coating.

[0027] The additive used in this composition fills the pores present in the wood fiberboard and envelops the wood fibers, thereby "sealing" them. On the other hand, the use of hydrophobic modifications creates a "hydrophobic coating" for the remaining pores and the still uncoated wood fibers.

[0028] To achieve the highest possible flexibility of the coating, the silane compounds are mixed with a suitable aqueous polymer dispersion. The polymers used have functional groups that are compatible with the inorganic silane matrix. This makes it possible to produce a coating with a high degree of crosslinking even at low temperatures.

[0029] The surfactant used in the composition reduces the surface tension of the preferably aqueous composition and supports the formation of dispersions with the swelling agent or acts as a solubilizer.

[0030] Although the use of a composition containing silanes and polymer dispersion is known from WO 2020 / 016176 A1, the composition mentioned in WO 2020 / 016176 A1 contains neither a swelling agent nor a surfactant. As already mentioned above, the addition of a swelling agent in combination with a surfactant not only has a water-repellent effect but also seals the joining edges of floor panels assembled to form a floating floor covering, thereby improving the tightness of the joints of the assembled panels compared to the composition of WO 2020 / 016176 A1 (see also Example 4). The improved effect of the composition according to the invention was surprising and unforeseeable.

[0031] This composition can be used for any board and adhesive system. The composition reduces swelling in wood fiberboards, regardless of the adhesive system used, varying porosity, or board thickness. The swelling-reducing effect of this composition has been demonstrated for HDF boards and particleboards with urea-formaldehyde glue (UF glue), melamine-urea-formaldehyde glue (MUF glue), or polyurethane-based glue (PMDI glue).

[0032] In one embodiment of the present composition, the at least one swelling agent is selected from a group of swellable natural or synthetic polymers or inorganic substances. Thus, the at least one swelling agent can be a swellable polymer selected from the group consisting of polysaccharides, preferably xanthan gum, starch, cellulose, modified cellulose, preferably ethylcellulose, pectins, and protein, preferably gelatin.

[0033] Xanthan gum is a naturally occurring polysaccharide. It is extracted from sugar-containing substrates using bacteria of the genus Xanthomonas and is used as a thickener and gelling agent in foods, among other things.

[0034] Ethylcellulose is a macromolecular substance derived semi-synthetically from naturally occurring cellulose. Chemically, it is a cellulose ether that exists in various types that differ in their degree of polymerization (molecular weight distribution) and degree of etherification.

[0035] In one embodiment, the starch used is selected from the group containing potato starch, corn starch, wheat starch or rice starch.

[0036] Starch is a polysaccharide with the formula (C6Hi0O5)n, consisting of alpha-D-glucose units. This macromolecule is therefore classified as a carbohydrate. Under heat, starch can physically bind, swell, and gelatinize many times its own weight in water. When heated with water, the starch swells at 47–57 °C, and at 55–87 °C (potato starch at 62.5 °C, wheat starch at 67.5 °C), starch paste is formed. This paste has different stiffening capacities depending on the type of starch (corn starch paste is greater than wheat starch paste, which is greater than potato starch paste) and decomposes more or less easily under acidification.

[0037] In a further embodiment, the at least one swelling agent is a swellable synthetic polymer selected from the group consisting of polyacrylates or inorganic substances such as silica gel. Phyllosilicates, however, are not intended as swelling agents.

[0038] In a particularly preferred embodiment, a copolymer of acrylic acid and acrylate is used as the swelling agent. Such acrylic-containing absorbents with particle sizes between 100 and 1000 μm are also known as superabsorbents, which are capable of absorbing many times their own weight in polar liquids such as water. Upon absorbing the liquid, the superabsorbent swells and forms a hydrogel. In this case, the swelling agent, in a particularly preferred embodiment, consists of a copolymer of potassium polyacrylate and polyamide.

[0039] Particularly preferred swelling agents are ethylcellulose, polyacrylates and / or xanthan.

[0040] The proportion of at least one swelling agent is between 0.3 and 5% by weight, preferably 1 and 4% by weight, based on the additive.

[0041] The rest X 1is advantageously selected from a group containing C 1-6 alkoxy, in particular methoxy, ethoxy, n-propoxy and butoxy, C 1-w aryloxy, in particular phenoxy, C 2-7 acyloxy, in particular acetoxy or propionoxy, and the radical X 2 is advantageously selected from a group containing H, C1-6-alkoxy, in particular methoxy, ethoxy, n-propoxy and butoxy, C6-io-aryloxy, in particular phenoxy, C 2-7 -acyloxy, especially acetoxy or propionoxy,

[0042] The organic residue R 1 is preferably selected from a group comprising C1-C3o-alkyl, in particular C5-C25-alkyl and C3-C8-cycloalkyl. In one embodiment, the organic R 1 selected from the group containing methyl, ethyl, n-propyl, isopropyl, n-butyl, s-butyl, t-butyl, pentyl, hexyl, cyclohexyl, preferably methyl, ethyl, propyl.

[0043] In one embodiment of the present composition, the at least one functional group Q1 selected from a group containing epoxy, methacrylic, methacryloxy, vinyl, cyano and / or isocyano groups. The functional group Q 1 can therefore advantageously have a residue with a double bond or an epoxy group, which can be activated and polymerized by means of UV radiation.

[0044] In a variant of the present composition, compounds of the general formula (I) according to R 1 a Six 1 (4-a), in particular R 1 Six 1 3, with a functional group Q 1 be selected from methacryloxypropyltrimethoxysilane (MPTS), silanes with an epoxy functionalization such as glycidyloxypropyltriethoxysilane, or silanes with a vinyl functionalization such as vinyltrimethoxysilane.

[0045] As described, the residue R 1 at least one functional group Q 1In a preferred embodiment, however, the radical R1 does not have one of the described functional groups Q1, in particular no polymerizable group, such as a double bond or epoxide bond.

[0046] In addition, the residue R 1 but substituted with further residues.

[0047] The term “substituted” refers to the substitution of one or more atoms, usually H atoms, by one or more of the following substituents, preferably by one or two of the following substituents: hydroxy, protected hydroxy, oxo, protected oxo, C3-cycloalkyl, bicyclic alkyl, phenyl, naphthyl, amino, protected amino, monosubstituted amino, protected monosubstituted amino, disubstituted amino, guanidino, protected guanidino, a heterocyclic ring, a substituted heterocyclic ring, such as pyrrolidinyl, imidazolyl, indolyl, C1-C12 alkoxy, C1-C12 acyloxy, acryloyloxy, carboxy, protected carboxy, carbamoyl, cyano, methylsulfonylamino, thiol, C1-C12 alkylthio and C1-C12 alkylsulfonyl. The substituted alkyl groups, aryl groups, alkenyl groups can be substituted once or multiple times, preferably once or twice, with the same or different substituents.

[0048] The term "aryl," as used herein, refers to aromatic hydrocarbons, for example, phenyl, benzyl, naphthyl, or anthryl. Substituted aryl groups are aryl groups that are substituted, as defined above, with one or more substituents as defined above.

[0049] The term “cycloalkyl” includes the groups cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and cycloheptyl.

[0050] In a particularly preferred variant of the present composition, the compound of general formula (I) corresponds to the formula SiX 1 4, where the remainder X 1 Alkoxy, especially methoxy, ethoxy, n-propoxy, or i-propoxy. Tetramethoxysilane and tetraethoxysilane are particularly preferred crosslinkers.

[0051] In a further embodiment of the present composition, the non-hydrolyzable organic radical R 2the compound according to formula (II) is selected from a group comprising C1-C15-alkyl, in particular C1-C10-alkyl, and C6-C10-aryl. These may be unsubstituted or substituted with another hydrophobic group. It is preferred if the non-hydrolyzable organic radical R 2 is selected from the group consisting of methyl, ethyl, n-propyl, isopropyl, n-butyl, s-butyl, t-butyl, pentyl, hexyl, heptyl, octyl, nonyl, cyclohexyl, phenyl, and naphthyl. Methyl, ethyl, propyl, octyl, or phenyl radicals are particularly preferred.

[0052] In the context of the present invention, the term “non-hydrolyzable organic residue” is understood to mean an organic residue which, in the presence of water, does not lead to the formation of an OH group or NH2 group linked to the Si atom.

[0053] The compound of formula (II) may in particular comprise one of the following formulas:

[0054] - R 2 Six 2 3with R2 as a C1-C10 alkyl group, preferably methyl, ethyl, propyl, pentyl, hexyl, heptyl, octyl, or as a C6-C10 aryl group, preferably phenyl and with X 2 as alkoxy, in particular methoxy, ethoxy, n-propoxy or i-propoxy, such as methyltriethoxysilane, octyltriethoxysilane, phenyltriethoxysilane.

[0055] In a variant of the present composition, a compound of the general formula (I) and a compound of the general formula (II) are used as additives.

[0056] In a further variant of the present composition, however, at least one compound of general formula (I) and at least two, preferably at least three, compounds of general formula (II) may also be present in the additive. Any combination is conceivable here. In a preferred embodiment, however, no more than four silane compounds are present in the composition.

[0057] The additive used in this composition may contain the following combinations:

[0058] - at least one SiX 1 4, where the remainder X 1 Alkoxy, especially methoxy, ethoxy, n-propoxy or i-propoxy, and at least one R 2 Six 2 3with R 2 as a C1-C10 alkyl group, preferably methyl, ethyl, propyl, pentyl, hexyl, heptyl, octyl, or as a C6-C10 aryl group, preferably phenyl and with X 2 as alkoxy, in particular methoxy, ethoxy, n-propoxy or i-propoxy, such as methyltriethoxysilane, octyltriethoxysilane, phenyltriethoxysilane; or

[0059] - at least one SiX 1 4, where the remainder X 1 Alkoxy, especially methoxy, ethoxy, n-propoxy or i-propoxy, and at least one R 2 Six 2 3with R 2as a C1 -C10 alkyl group, preferably methyl, ethyl, propyl, pentyl, hexyl, heptyl, octyl, such as methyltriethoxysilane, octyltriethoxysilane and at least one R 2 Six 2 3with R 2 as a C6-C10 aryl group, preferably phenyl and with X 2 as alkoxy, especially methoxy, ethoxy, n-propoxy or i-propoxy, such as phenyltriethoxysilane. or

[0060] - at least one SiX 1 4, where the remainder X 1 Alkoxy, especially methoxy, ethoxy, n-propoxy or i-propoxy, and at least two R 2 Six 2 3with R 2 as a C1 -C10 alkyl group, preferably methyl, ethyl, propyl, pentyl, hexyl, heptyl, octyl, such as methyltriethoxysilane, octyltriethoxysilane and at least one R 2 Six 2 3with R 2 as a C6-C10 aryl group, preferably phenyl and with X 2 as alkoxy, in particular methoxy, ethoxy, n-propoxy or i-propoxy, such as phenyltriethoxysilane.

[0061] Furthermore, in one variant, the composition may contain tetraethoxysilane as a compound of formula (I) and methyltriethoxysilane and phenyltriethoxysilane as compounds of formula (II).

[0062] In another variant, the composition contains tetraethoxysilane as a compound of formula (I) and methyltriethoxysilane, phenyltriethoxysilane and octyltriethoxysilane as compounds of formula (II).

[0063] In a further embodiment, the compound of general formula (I) is contained in the composition in a molar amount between 0.08 - 0.2 mol, preferably 0.1 - 0.15 mol, particularly preferably 0.1 - 0.12 mol and the compound of general formula (II) is contained in a molar amount between 0.05 and 0.1 mol, preferably between 0.06 and 0.09 mol, particularly preferably between 0.07 and 0.08 mol.

[0064] The range of the molar amount given for the compound of the general compound (II) can refer to one compound or to the sum of two compounds or three compounds of the general formula (II)

[0065] Thus, in the variant of the composition of tetraethoxysilane as a compound of formula (I) and methyltriethoxysilane and phenyltriethoxysilane as compounds of formula (II), 0.15 mol of tetraethoxysilane and 0.04 mol of methyltriethoxysilane / 0.033 mol of phenyltriethoxysilane may be contained.

[0066] In the other variant of the composition of tetraethoxysilane as a compound of formula (I) and methyltriethoxysilane, phenyltriethoxysilane and octyltriethoxysilane as compounds of formula (II), 0.1 mol of tetraethoxysilane and 0.03 mol of methyltriethoxysilane, I 0.025 mol of phenyltriethoxysilane and 0.043 mol of octyltriethoxysilane may be contained.

[0067] The ratio of the silane compound of formula (I) to the silane compounds of formula (II) is preferably between 1:0.5 and 1:2, particularly preferably between 1:0.75 and 1:1.5, most preferably between 1:1 and 1:1.2.

[0068] In a further embodiment of the present composition, the at least one polymer is selected from the group comprising polyurethanes, epoxy resins; melamine resins, such as melamine-formaldehyde resin, and polyacrylates.

[0069] In the present case, the use of a polyurethane polymer is preferred, wherein the polyurethane polymer is based on aromatic polyisocyanates, in particular polydiphenylmethane diisocyanate (PMDI), toluene diisocyanate (TDI) and / or diphenylmethane diisocyanate (MDI), wherein PMDI is particularly preferred.

[0070] The polymer is incorporated into the network formed from the silane compounds and gives the composition flexible properties that facilitate application.

[0071] The type of polymer used is preferably matched to the silane compounds used. For example, it is advantageous to use epoxy-modified silanes together with epoxy polymers, and methacrylate-modified silanes together with acrylate polymers.

[0072] In a further embodiment of the present composition, it is also possible to use more than one polymer.

[0073] In a further embodiment, the polymer content in the presently used composition is at least 30 wt%, preferably at least 20 wt%, particularly preferably at least 10 wt%. In one embodiment, the ratio of sol-gel to polymer is between 1:0.1 and 1:0.5, preferably between 1:0.2 and 1:0.4 (based on the solids).

[0074] The solvent content, which is essentially determined by the use of silanes, is between 1 and 15 wt.%, preferably 2 to 13 wt.%, particularly preferably between 4 and 10 wt.%. However, these figures do not initially take into account the solvent content of the polymer used. Solvents are, in particular, water and / or alcohols, preferably ethanol here. The alcohol content can be, for example, < 1%. It is also possible for the present composition to contain exclusively alcohol and little or no water, i.e., the silane compounds and also the polymer dispersion can be used in an alcoholic form.

[0075] In a further embodiment, the present composition can contain inorganic particles, in particular SiO2, Al2O3, ZrO2, TiO2 particles. The particles preferably used here have a size between 2 and 400 nm, preferably between 2 and 100 nm, particularly preferably between 2 and 50 nm. The addition of the inorganic particles increases the solids content of the composition, thereby improving the application behavior of the composition. The addition of inorganic particles also prevents shrinkage and cracking. The inorganic particles can be used in an amount range of 0.1 to 25 wt.%, preferably 5 to 20 wt.%, based on the solids content of the silane material (sol-gel material).

[0076] The additive used in this composition may contain the following combinations:

[0077] - at least one SiX 1 4, where the remainder X 1Alkoxy, especially methoxy, ethoxy, n-propoxy or i-propoxy, and at least one R 2 Six 2 3with R 2 as a C1-C10 alkyl group, preferably methyl, ethyl, propyl, pentyl, hexyl, heptyl, octyl, or as a C6-C10 aryl group, preferably phenyl and with X 2 as alkoxy, in particular methoxy, ethoxy, n-propoxy or i-propoxy, such as methyltriethoxysilane, octyltriethoxysilane, phenyltriethoxysilane, polyurethane and optionally SiO2 particles; or

[0078] - at least one SiX 1 4, where the remainder X 1 Alkoxy, especially methoxy, ethoxy, n-propoxy or i-propoxy, and at least one R 2 Six 2 3with R 2 as a C1 -C10 alkyl group, preferably methyl, ethyl, propyl, pentyl, hexyl, heptyl, octyl, such as methyltriethoxysilane, octyltriethoxysilane and at least one R 2 Six 2 3with R 2 as a C6-C10 aryl group, preferably phenyl and with X 2as alkoxy, in particular methoxy, ethoxy, n-propoxy or i-propoxy, such as phenyltriethoxysilane, polyurethane and optionally SiO2 particles, or

[0079] - at least one SiX 1 4, where the remainder X 1 Alkoxy, especially methoxy, ethoxy, n-propoxy or i-propoxy, and at least two R 2 Six 2 3with R 2 as a C1 -C10 alkyl group, preferably methyl, ethyl, propyl, pentyl, hexyl, heptyl, octyl, such as methyltriethoxysilane, octyltriethoxysilane and at least one R 2 Six 2 3with R 2 as a C6-C10 aryl group, preferably phenyl and with X 2as alkoxy, in particular methoxy, ethoxy, n-propoxy or i-propoxy, such as phenyltriethoxysilane, polyurethane, and optionally SiO2 particles. A particularly preferred variant of the present composition comprises tetraethoxysilane, methyltriethoxysilane, phenyltriethoxysilane, octyltriethoxysilane, and polyurethane, and optionally SiO2 particles. A very particularly preferred variant of the present composition comprises tetraethoxysilane, methyltriethoxysilane, phenyltriethoxysilane, octyltriethoxysilane, polyurethane, and SiO2 particles.

[0080] As mentioned above, the present composition according to the invention contains at least one surfactant. The surfactant reduces the surface tension of the preferably aqueous composition and supports the formation of dispersions with the swelling agent or acts as a solubilizer.

[0081] Possible surfactants are anionic surfactants and cationic surfactants based on quaternary ammonium compounds.

[0082] Anionic surfactants that can be used include alkyl carboxylates, alkylbenzenesulfonates, preferably sodium dodecylbenzenesulfonate, secondary alkylsulfonates, fatty alcohol sulfates such as sodium lauryl sulfate, or alkyl ether sulfates such as sodium dodecylpoly(oxyethylene) sulfate. Sodium dodecylbenzenesulfonate is preferred.

[0083] The amount of surfactant added is between 0.1 and 0.2 wt%, preferably between 0.12 and 0.15 wt% based on the additive of silane and polymer.

[0084] The described composition comprising at least one swelling agent, at least one additive of at least two silanes and one polymer (as described above) and at least one surfactant is used for coating and sealing profiles, the upper regions of a joining edge and / or for bevels (for V-joints).

[0085] The composition used to coat and seal edges and / or bevels of wood-based panels and correspondingly applied to the edges and / or bevels of the wood-based panel is preferably free of chromium-containing compounds classified as hazardous to health. Furthermore, the composition is preferably free of zinc-containing and / or halogen-containing, in particular chlorine-containing, substances. In a further embodiment, at least one bevel color system is added to the present composition. The bevel color system comprises color pigments and an aqueous solvent or suspending agent. Carbon black, iron oxides, titanium dioxide, and / or organic pigments are used as color pigments. Suitable solvents or suspending agents are melamine resin-formaldehyde resins or acrylates. In one embodiment, the bevel color comprises color pigment, acrylate, and water.

[0086] Accordingly, a coating system or sealing system comprising at least one swelling agent, at least one additive comprising at least two silanes and a polymer as described above, at least one surfactant, at least one bevel color, and a suspending agent, preferably an aqueous acrylate, is also provided. This coating system is preferably used for coating and sealing joining edges and / or bevels (for V-joints).

[0087] According to a first embodiment, the present composition can be prepared in a process comprising the following steps:

[0088] Providing at least one dispersion A) comprising polymer dispersion and optionally a dispersion of inorganic particles,

[0089] - Providing a solution B) comprising a mixture of at least one compound of the general formula (I), at least one compound of the general formula (II) and at least one catalyst, in particular an acid,

[0090] - Addition of solution B) to dispersion A) and neutralization of the additive mixture (e.g. by addition of a basic compound);

[0091] - separating the aqueous phase of the additive from polymer dispersion, at least one compound of formula (I) and at least one compound of formula (II), and

[0092] - Addition of at least one surfactant to the aqueous additive phase,

[0093] - Addition of at least swelling agent to the aqueous additive phase,

[0094] - Optional addition of at least one bevel color system.

[0095] Inorganic and / or organic acids suitable as catalysts are selected from a group consisting of phosphoric, acetic, p-toluenesulfonic, hydrochloric, formic, or sulfuric acid. Ammonium salts such as ammonium sulfate, which react as weak acids, are also suitable. p-toluenesulfonic acid is particularly preferred. For subsequent neutralization of the reaction mixture, a basic compound such as ammonia or NaOH is preferably added. This leads to a separation of the aqueous phase containing the binder component from the alcoholic phase (ethanolic phase). The aqueous phase can then be easily separated from the alcoholic phase.

[0096] In the case that inorganic particles are mixed into the binder composition, the inorganic particles are preferably used in an amount between 0.1 to 15 wt%, preferably 0.5 to 10 wt%, particularly preferably between 1 to 5 wt%.

[0097] The addition of at least surfactant enables better suspension of the subsequently added swelling agent, as described above.

[0098] Depending on the swelling agent added, an increase in viscosity occurs. This increase in viscosity is influenced by the swelling agent used and can lead to undesirable gel formation, which affects further use of the composition.

[0099] The viscosity of the present composition is determined by the flow time using a flow cup according to EN ISO 2431:2011 (Paints and varnishes - Determination of flow time using flow cups, 4 mm nozzle, 21 °C).

[0100] The flow time of a composition containing at least one surfactant is between 10 and 60 seconds, preferably between 12 and 40 seconds, more preferably between 15 and 30 seconds. Without surfactant, the flow time of the composition is more than 60 seconds.

[0101] When using xanthan as a swelling agent, it has proven advantageous, for example, to first mix an aqueous xanthan solution with at least one silane of the general formula R 2 Six 2 3with R 2 as a C1 -C10 alkyl group, preferably methyl, ethyl, propyl, pentyl, hexyl, heptyl, octyl, and with X 2as alkoxy, in particular methoxy, ethoxy, n-propoxy or i-propoxy, such as methyltriethoxysilane. The addition of the silane prevents gel formation of the xanthan gum. In a further step, the composition comprising at least one swelling agent, at least one additive comprising at least two silanes and a polymer (as described above), and at least one surfactant can be added to a fiber color system (comprising fiber color and suspending agent). The amount added to the fiber color system can be up to 20% by weight, preferably up to 30% by weight, particularly preferably up to 40% by weight, even more preferably up to 50% by weight.

[0102] As already mentioned above, the present composition can be used for coating or sealing joint edges, profiles and / or bevels of wood-based panels, in particular WPC, chipboard, HDF or MDF panels.

[0103] Preferably, the wood-based panel coated and sealed with the described composition is an HDF or MDF or chipboard, wherein the joining edges, profiles and / or bevels of the wood-based panel are coated for the purpose of sealing.

[0104] The composition can be applied to the joining edges, profiles and / or bevels of the wood-based panel, e.g. by spraying, rolling or using a vacuum.

[0105] The layer thickness of the composition on the plate edge and / or bevel can be in a range between 10 and 50 pm, preferably between 20 and 40 pm.

[0106] The composition can be applied in liquid form with a quantity between 100 and 200 silane fl. g / m 2 , preferably between 120 and 150 silane fl. g / m 2 applied to the board edges and / or bevels. This results in a solids content on the board edge of between 5 and 25 mg / cm 2, preferably between 10 and 20 mg / cm 2 .

[0107] Wood-based panels, such as particle boards and fiberboards such as MDF and HDF boards, are made from wood chips or wood fibers that are obtained by chipping the wood chips in a chipper or by defibrating the wood chips in a refiner. The wood fibers used in wood fiber boards have a length of between 1.5 mm and 20 mm and a thickness of between 0.05 mm and 1 mm. The size of the wood chips used in wood chipboards depends on whether they are used in the top layer or middle layer. In the middle layer, the chips start at a mesh size of > 0.125 mm, while in the top layer they start at > 0.8 - 1.0 mm. These wood-based panels can have various binder systems that are mixed and pressed with the wood fibers as a binding agent.Preferred binder systems are: formaldehyde resins, such as urea-formaldehyde resins, melamine-formaldehyde resins, melamine-urea-formaldehyde resins; polyurethanes, preferably based on polydiphenylmethane diisocyanate (PMDI), epoxy resin, or polyester resins.

[0108] These wood-based panels can also be coated on the top surface with foils, e.g., foils made of thermoplastic materials such as PVC or PP, or paper impregnates, such as impregnated with decorative paper layers or overlay papers. Overlay, decorative, counterweight, and kraft paper impregnates are based on thin paper layers that are fully or partially saturated (impregnated) with a resin, preferably melamine-formaldehyde resin.

[0109] Impregnations can be applied, for example, in an impregnation bath, by rolling, anilox rollers, by doctor blades, or by spraying. In one variant, the paper layers are treated as follows: First, the back of the paper layer is impregnated (e.g., in an impregnation tank) with a resin with a solids content between 50 and 70 wt%, preferably 60 wt%. After passing through an air gap, immersion impregnation with a resin follows. Excess resin is removed in a doctor blade system / pair of squeeze rollers, and optionally (in the case of an overlay paper layer), abrasion-resistant particles are sprinkled onto the impregnated paper layer. A drying step follows to a residual moisture content of approximately 6%.

[0110] In the case of coated wood-based panels, these papers (decorative, overlay) are applied to the wood-based panels and pressed together. Typically, the impregnated decorative paper is first applied to the top side of the wood-based panel. The decorative impregnated paper is then followed by at least one overlay impregnated paper. The counter-layer impregnated paper is pressed onto the underside of the wood-based panel. A typical structure of a coated HDF panel, from top to bottom, is: overlay impregnated paper, decorative impregnated paper, HDF core, counter-layer impregnated paper.

[0111] In one embodiment, it is also provided to apply a veneer to a wood-based panel. Such veneers typically have a surface finish based on UV or ESH varnishes. The veneers are glued onto the wood-based panel (HDF, particleboard, OSB, etc.). Urea or PVAc glues, with or without hardeners, are usually used to bond the veneers to the substrate.

[0112] It is also possible to press the veneer onto the wood-based panel in a short-cycle press using paper impregnated with melamine resin (e.g., an overlay). The pressing parameters are approximately T > 150°C, p > 30 bar, and t > 30 see. This technology can also be used to produce veneer flooring with veneers that are approximately 0.5 mm thick. It is crucial that the melamine resin penetrates as far as possible into the veneer during the pressing process. This not only reinforces the veneer with the synthetic resin, but also fixes the veneer compressed by the pressing. However, the melamine resin should not ooze out of the veneer, as this would cause discoloration of the surface and adhesion problems during subsequent painting or oiling.

[0113] In a preferred embodiment, a particle board pressed with a veneer is used. For this purpose, in a first step, a resin-impregnated paper (preferably a resin-impregnated kraft paper) with a veneer is applied to a particle board (e.g., on the top side) and pressed together. In a more advanced variant, a resin-impregnated paper and / or a veneer are used as the counterlayer.

[0114] It is also possible for the wood-based panel to be coated with liquid resin layers (liquid coating) and pressed. In this process, a primer layer is first applied to the wood-based panel, followed by a layer of primer, which is then printed to form a decorative layer. Additional resin layers are then applied to the decorative layer as protective and wear-resistant layers. The wood-based panel can accordingly have at least one decorative layer on the top surface and a multi-layer resin structure containing abrasion-resistant particles, cellulose fibers, and glass beads.The following layer structure is possible (from bottom to top): Backing layer consisting of six resin layers - wood-based panel - primer layer - printed decorative layer - protective layer, in particular a protective layer made of a not yet fully cured resin - first resin layer with cellulose fibers - layer of abrasion-resistant particles - second resin layer - third resin layer with glass beads - fourth resin layer with glass beads - fifth resin layer with glass beads - sixth resin layer (without glass beads). The protective layer serves to cover the decorative layer and protect it during intermediate storage (stacking, storage, transport). The additional resin layers on the top side together form an overlay that protects the finished laminate against abrasion and enables structuring in synchronization with the decorative layer.

[0115] When using the described wood-based panels as floor panels, the wood-based panels are provided with a tongue-and-groove interlock and used for floating installation. A corresponding installation method involves laying a first floor panel and attaching a second floor panel to the first floor panel, with the tongue of the second floor panel being inserted into the groove of the first floor panel.

[0116] After installation, the beveled floor panels form V-shaped joints that are sealed by the applied composition of bevel paint and additive and protected against moisture penetration.

[0117] The invention is explained in more detail below with reference to exemplary embodiments.

[0118] Embodiment 1: Preparation of a sealing composition according to a first embodiment

[0119] 28.8 g of an aqueous SiO2 dispersion (Köstrosol 3550) and 20 g of an aqueous polyurethane solution Alberdingk U 3215 are placed in a reaction vessel.

[0120] In parallel, 12.3 g of octyltriethoxysilane, 2.4 g of methyltriethoxysilane / triethoxy(methyl)silane or 6.1 g of phenyltriethoxysilane, 20.8 g of tetraethoxysilane, and 28.8 g of water are heated to 50 °C and stirred. 2.8 g of sulfuric acid are then added while stirring and the mixture is stirred for 120 minutes. This solution is then stirred into the above suspension while still warm and stirred at room temperature for a further 60 minutes. A 0.1 molar NaOH solution is added until a pH of 7.5 is reached.

[0121] After 24 hours of standing, the alcoholic phase is separated using a separatory funnel. 0.13 g of the surfactant sodium dodecylbenzenesulfonate is then added.

[0122] A swelling agent is now added to this solution, which is prepared as follows: 10 g of xanthan is dissolved in 100 g of demineralized water, after 30 minutes the solution is heated to 80 °C and 0.78 g of methyltriethoxysilane is added and stirred for another 60 minutes.

[0123] Now, 20.1 g of the aqueous xanthan gum solution are added to 100 g of the above solution. When pure xanthan gum is added at this concentration, the solution thickens considerably, and gel formation occurs.

[0124] The additive (ino®sil AS-II) can now be added up to 50 wt.% to a commercially available edge coating system, which remains stable for several weeks. After application, curing occurs thermally (e.g., 100 °C, 5 minutes).

[0125] Embodiment 2: Preparation of a sealing composition according to a second embodiment

[0126] 28.8 g of an aqueous SiO2 dispersion (Köstrosol 3550) and 20 g of an aqueous polyurethane solution Alberdingk U 3215 are placed in a reaction vessel.

[0127] In parallel, 12.3 g of octyltriethoxysilane, 2.4 g of methyltriethoxysilane, 6.1 g of phenyltriethoxysilane, 20.8 g of tetraethoxysilane, and 28.8 g of water are heated to 50 °C and stirred. 2.8 g of sulfuric acid are then added while stirring for 120 minutes. This solution is then stirred into the above suspension while still warm and stirred at room temperature for a further 60 minutes. A 0.1 molar NaOH solution is added until a pH of 7.5 is reached.

[0128] After 24 hours of standing, the alcoholic phase is separated using a separatory funnel. 0.13 g of the surfactant sodium dodecylbenzenesulfonate is then added.

[0129] To 100 g of the above solution, 1.5 g of ethylcellulose is added as a swelling agent. This results in a slight increase in viscosity.

[0130] The additive (ino® sil AS-I) can now be added up to 50 wt. % to a commercially available edge coating system, which remains stable for several weeks. Curing after application occurs thermally (e.g., 100 °C, 5 minutes). Embodiment 3: Production of a sealing composition according to a third embodiment.

[0131] 28.8 g of an aqueous SiO2 dispersion (Köstrosol 3550) and 20 g of an aqueous polyurethane solution Alberdingk U 3215 are placed in a reaction vessel.

[0132] In parallel, 12.3 g of octyltriethoxysilane, 2.4 g of methyltriethoxysilane, 6.1 g of phenyltriethoxysilane, 20.8 g of tetraethoxysilane, and 28.8 g of water are heated to 50 °C and stirred. 2.8 g of sulfuric acid are then added while stirring for 120 minutes. This solution is then stirred into the above suspension while still warm and stirred at room temperature for a further 60 minutes. A 0.1 molar NaOH solution is added until a pH of 7.5 is reached.

[0133] After 24 hours of standing, the alcoholic phase is separated using a separatory funnel. 0.13 g of the surfactant sodium dodecylbenzenesulfonate is then added.

[0134] To 100 g of the above solution, 0.8 g of a polyacrylic-based superabsorbent is added as a swelling agent. Even at a small dosage, the viscosity increases significantly.

[0135] The additive (ino® sil AS-HI) can now be added up to 50 wt.% to a commercially available edge coating system, which remains stable for several weeks. After application, curing occurs thermally (e.g., 100 °C, 5 minutes).

[0136] Example 4: NALFA test on samples with edge sealing

[0137] A NALFA test was conducted according to ISO 4760 EN. For this purpose, a composition from Example 1 was compared with a composition from WO 2020 / 01676 A1.

[0138] Comparative composition from WO 2020 / 01676 A1 :

[0139] 12.3 g of octyltriethoxysilane, 2.4 g of trimethylsilane, 6.1 g of phenyltriethoxysilane, 20.8 g of tetraethoxysilane, and 28.8 g of an aqueous SiO2 dispersion (50 wt.%) from Obermaier are initially charged, heated to 80 °C, and stirred. 3.6 g of para-toluic acid in water (30 wt.%) are then added while stirring and the mixture is stirred for 120 minutes. After a further 24 hours, the pH is raised to 7 by adding a 25% ammonia solution (6.2 g in the above example) while stirring.

[0140] After a further stirring time of 2 hours, 80 g of water is added, stirred again for 30 minutes and then the suspension is stored for 4 hours without stirring.

[0141] After this waiting period, the aqueous phase containing the binder separates from the ethanolic phase. The aqueous phase is then separated using a separating funnel, thus yielding the inorganic aqueous coating system.

[0142] 50 g of this coating system (solids: 52%) is now mixed with 20 g of an aqueous polyurethane solution (Alberdingk U 3251, solids: 35%).

[0143] The coating system can now be applied to an edge using a foam roller or a pipette and thermally cured (e.g. 100 °C, 5 minutes).

[0144] The results of the NALF tests are shown in the following table.

[0145] As can be seen from the table, the percentage of NALFA test passes almost doubled when using the composition of Example 1 compared to the composition known from WO2020016176A1. Accordingly, the tightness of the joints of assembled floor panels is increased when using the composition of Example 1.

Claims

Claims 1. A wood-based panel comprising at least one composition applied to edges and / or bevels of the wood-based panel for sealing and coating the edges and / or bevels, wherein the composition comprises a) at least one swelling agent, b) at least one additive comprising at least one compound of the general formula (I) R 1 aSiX 1 (4-a) (I), where - X 1 Alkoxy, aryloxy, acyloxy, and - R 1 an organic radical is selected from the group comprising alkyl, aryl, cycloalkyl, which may be interrupted by -O- or -NH-, and - where R 1 has at least one functional group Qi selected from a group containing an acrylic, acryloxy, methacrylic, methacryloxy, cyano, isocyano and epoxy group, and - a = 0, 1, 2, 3, in particular 0 or 1, - at least one compound of general formula (II) R 2 bSiX 2 (4-b) (II), where - X 2 alkoxy, aryloxy, acyloxy, - R 2 a non-hydrolyzable organic residue R 2 is selected from the group comprising alkyl and aryl, and - b = 1 , 2, 3, or 4, and - at least one aqueous polymer dispersion, and c) at least one surfactant, preferably at least one anionic surfactant.

2. A wood-based panel with a composition according to claim 1, characterized in that the at least one swelling agent is a swellable polymer selected from the group comprising polysaccharides, preferably xanthan gum, starch, cellulose, modified cellulose, pectins, protein, preferably gelatin.

3. Wood-based panel with a composition according to one of the preceding claims, characterized in that the at least one swelling agent is a swellable synthetic polymer selected from the group containing polyacrylates, or silica gel.

4. A wood-based panel with a composition according to one of the preceding claims, characterized in that the proportion of at least one swelling agent is between 0.3 and 5% by weight, based on the additive.

5. Wood-based panel with a composition according to one of the preceding claims, characterized in that at least one anionic surfactant is selected from a group containing alkyl carboxylates, alkylbenzenesulfonates, preferably sodium dodecylbenzenesulfonate, secondary alkylsulfonates, fatty alcohol sulfates, such as sodium lauryl sulfate, or alkyl ether sulfates, such as sodium dodecylpoly(oxyethylene) sulfate, 6. Wood-based panel with a composition according to one of the preceding claims, characterized in that at least one bevel color system is added.

7. Wood-based panel with a composition according to one of the preceding claims, characterized in that at least one compound of the general formula (I) and at least two, preferably at least three compounds of the general formula (II) are contained.

8. Wood-based panel with a composition according to one of the preceding claims, characterized in that X 1 is selected from a group containing C1-6-alkoxy, in particular methoxy, ethoxy, n-propoxy and butoxy, C6-io-aryloxy, in particular phenoxy, C2-7-acyloxy, in particular acetoxy or propionoxy, and X 2 is selected from a group containing H, Ci-6-alkoxy, in particular Methoxy, ethoxy, n-propoxy and butoxy, Ce-wAryloxy, especially phenoxy, C2-7-acyloxy, especially acetoxy or propionoxy, 9. Wood-based panel with a composition according to one of the preceding claims, characterized in that the compound of general formula (I) of the formula SiX 1 4, especially with X 1 Alkoxy, in particular methoxy, ethoxy, n-propoxy or i-propoxy.

10. Wood-based panel with a composition according to one of the preceding claims, characterized in that the non-hydrolyzable organic R 2 is selected from a group comprising C1-C15-alkyl, in particular C1-C10-alkyl, and C6-C10-aryl, preferably methyl, ethyl, n-propyl, isopropyl, n-butyl, s-butyl, t-butyl, pentyl, hexyl, heptyl, octyl, nonyl, cyclohexyl, phenyl and naphthyl.

11. Wood-based panel with a composition according to one of the preceding claims, characterized in that the compound of formula (II) comprises one of the following formulas: - R 2 Six 2 3with R 2 as a C1-C10 alkyl group, preferably methyl, ethyl, propyl, pentyl, hexyl, heptyl, octyl, or as a C6-C10 aryl group, preferably phenyl and with X 2 as alkoxy, in particular methoxy, ethoxy, n-propoxy or i-propoxy.

12. Wood-based panel with a composition according to one of the preceding claims, characterized in that the at least one polymer of the polymer dispersion is selected from the group containing polyurethanes, in particular polydiphenylmethane diisocyanate (PMDI), epoxy resins, melamine resins, polyacrylates.

13. Wood-based panel with a composition according to one of the preceding claims, characterized in that inorganic particles, in particular SiO2, Al2O3, ZrO2, TiO2 particles, may be included.

14. A process for producing a composition for coating and sealing edges and / or bevels of a wood-based panel according to any one of the preceding claims, comprising the following steps: Providing at least one dispersion A) comprising polymer dispersion and optionally a dispersion of inorganic particles, - Providing a solution B) comprising a mixture of at least one compound of the general formula (I), at least one compound of the general formula (II) and at least one catalyst, in particular an acid, - Addition of solution B) to dispersion A) and neutralization of the additive mixture, preferably addition of a basic compound; - separating the aqueous phase of the additive from polymer dispersion, at least one compound of formula (I) and at least one compound of formula (II), - Addition of at least one surfactant, and - Addition of at least one swelling agent to the aqueous additive phase, - Optional addition of at least one bevel color system.

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