EP4364918A1 - Method for producing a chipboard and chipboard - Google Patents

Abstract

The invention relates to a method for coating a waterproof chipboard (1) in order to make the chipboard better and more versatile, wherein the chipboard comprises wood chips and at least one adhesive with an adhesive content of at least 12 wt. % /dry wood, with the steps:- providing the chipboard (1), which has a top side (1a) and a bottom side (1b) and side surfaces,- applying a coating,- applying a decoration (2),- if necessary structuring the coating, in each case on at least one section of a top side (1a), a bottom side (1b) or a side surface, and- if necessary curing the coating. The invention further relates to a coated, waterproof chipboard (1).

Description

The invention relates to a method for producing a chipboard and a chipboard, in particular a waterproof chipboard.

Chipboards with an adhesive content of at least 12% that are dimensionally stable in the presence of moisture are called waterproof chipboards. Such chipboards have a relatively rough and aesthetically unappealing surface.

The object of the invention is to make such a waterproof chipboard better and more versatile.

The object is achieved by a method according to claim 1 and a chipboard according to claim 10. Dependent claims relate to advantageous developments of the invention.

The chipboard has an adhesive content of at least 12% by weight / dry wood. Based on the proportion of wood or chips, an adhesive content of at least 15% by weight / dry wood, preferably at least 17% by weight / dry wood, particularly preferably at least 20% by weight / dry wood, very particularly preferably at least 25% by weight / dry wood is applied to the chips. Provided that an upper limit for the moisture content of the layer and/or layers of the chip cake is observed after gluing, any desired amount of adhesive can be applied to the chips. The upper limit of the moisture content is preferably between 1% by weight / glued wood to 20% by weight / glued wood, preferably between 3% by weight / glued wood to 18% by weight / glued wood, particularly preferably between 5% by weight / glued wood to 15% by weight / glued wood.

The adhesive content is expressed in relation to the chips, i.e. the adhesive content is given in relation to the weight of the chips used. For chips that can absorb moisture (e.g. wood chips), the adhesive content is based on wood dried to constant weight. The chips are dried to constant weight at 103±2 °C and referred to as absolutely dry wood (atro wood: absolutely dry wood). The adhesive content is given as 100% solids, i.e. without any added liquid.

Lignocellulosic material is used to produce chips, such as wood, e.g. round wood, fresh wood, old wood or leftover wood or annual plants, typically straw or bagasse. The chips preferably have a length of 0.5 mm to 50 mm, a width of 0.1 to 20 mm and a thickness of 0.05 mm to 2 mm. A distinction is often made between coarse chips with a length of 5 mm to 50 mm, a width of 1 to 20 mm and a thickness of 0.2 to 2 mm and fine chips with a length of 0.5 mm to 25 mm, a width of 0.1 to 5 mm and a thickness of 0.05 to 1 mm.

The high adhesive content when gluing the chips allows the production of a water-resistant and therefore moisture-resistant chipboard that is also very strong. It has also surprisingly been found that swelling of the chipboard, e.g. due to 24 hours of water storage, is reversible due to the high adhesive content. The swelling behavior is preferably determined according to DIN EN 317. After 24 hours of re-drying, e.g. at room temperature, the chipboard regains its original dimensions, e.g. initial length, initial width and initial thickness before 24 hours of water storage. From this it can be concluded that the adhesive bonds remain essentially undamaged during exposure to water. This swelling-shrinkage behavior has not previously been observed in chipboards; rather, a partial, irreversible residual swelling was common. The complete reversal of the deformation caused by swelling has opened up new areas of application for chipboard.

It is particularly preferred to use an adhesive for the production of the chipboard that a first, thermosetting component and a second, thermoplastic component. The adhesive is used in a proportion of at least 12 wt.%/dry wood to 60 wt.%/dry wood, preferably from 15 wt.%/dry wood to 45 wt.%/dry wood, particularly preferably from 18 wt.%/dry wood to 35 wt.%/dry wood, in particular from 20 wt.%/dry wood to 33 wt.%/dry wood, advantageously from 24 wt.%/dry wood to 31 wt.%/dry wood.

According to an advantageous embodiment of the invention, a condensation resin, in particular aminoplasts, such as melamine-formaldehyde resin, urea-formaldehyde resin (UF resin), or benzoguanamine resin, as well as phenolplasts, such as phenolformaldehyde resin (PF resin), are used as the thermosetting component, either individually or in a mixture. Aminoplasts are used in aqueous solution, e.g. as melamine resin, usually as melamine-formaldehyde resin (MF resin), the solids content of the aminoplast preferably being at least 45% by weight based on the aqueous solution; the solids content is advantageously over 50% by weight. The upper limit of the solids content is determined by the solubility and, if applicable, processability of the aminoplast in the production process, e.g. in spray nozzles or high-pressure gluing processes.

The adhesive preferably comprises melamine resin, e.g. MF resin (melamine formaldehyde resin), at least as a first component. Melamine resin is preferred because it has little swelling and is not very hygroscopic and is resistant to hydrolysis. Alternatives are phenolic resin, urea resin or mixtures or combinations of several of these thermosetting first components. Although urea resin is not resistant to water, it can surprisingly be used, especially in a mixture with melamine resin and/or phenolic resin, to produce the chipboard according to the invention. Melamine resin in particular can be used either alone as the first component or in combination with one or more of the other thermosetting components. The proportion of UF resin is preferably up to 50% by weight of the MF or PF resin, without the water resistance or strength of the chipboard being impaired.

In combination means in the context of this invention that mixtures of resins of the first component can be used, whereby either the A mixture of two or more resins of the first components is applied to the chips at the same time. Or several different resins of the first component are used one after the other, e.g. because they cannot be used in a mixture or because separate application of different resins of the first component or individual resins of the first component of the adhesive has a beneficial effect, e.g. on the subsequent product and/or application properties.

Preferably, technical diphenylmethane diisocyanate (PMDI) is applied to the chips as the second, thermoplastic component of the adhesive. Alternatively or additionally, other substances such as methylene diphenyl isocyanate (MDI), also in emulsified form as eMDI, but also polyurethane can be used as the second component. The proportion of the second component is preferably more than 1% by weight, in particular 3% by weight or more, advantageously 5% by weight or more, in each case based on dry wood. The proportion of the second component, e.g. PMDI, in the chipboard according to the invention is therefore significantly higher than in conventional chipboards. Advantageously, the second component of the adhesive, e.g. PMDI, is also used in a multi-layer structure of the board, or in particular in the cover layers of the chipboard according to the invention. Preferably, the second component is used in the same amount in the middle layer and in the cover layer. Here, too, several substances that are suitable as the second component can be applied to chips either in a mixture with one another at the same time or individually one after the other.

Preferably, at least one third component, for example polyol or polyether, can be added to the first and second components of the adhesive, preferably in the form of a solid. The third component can be added in a proportion of up to 15% by weight, preferably up to 10% by weight, particularly preferably in a proportion of 2 to 5% by weight, based on the total amount of the adhesive.

According to an advantageous embodiment, the chipboard can be modified, in particular improved, in its elastic properties by adding an elastomer or thermoplastic, which is used as an elasticizing additive, e.g. by adding polyvinyl acetate (PVAc) or ethyl vinyl acetate (EVA). Acrylate, styrene acrylate or polyurethane (PU) are preferred for elasticizing the chipboard according to the invention. Chipboard is used in particular in the form of a liquid additive such as a dispersion or emulsion because they are waterproof. Acrylate, styrene acrylate and PU with a glass transition temperature of TG less than 0 °C are preferably used. Mono- or diethylene glycol are also suitable for elasticising the chipboard. The elasticising additives mentioned above can be used on their own or in mixtures. The addition of elastomers or thermoplastics reduces the brittleness of the chipboard and improves its elastic properties, e.g. the E-modulus. In addition, the addition of elasticising additives results in the chipboard according to the invention lying flatter. The elasticising additive is calculated as a solid proportionate to the total amount of chipboard (atro) in an amount of 1 wt.% up to 5 wt.%, advantageously 2 wt.% to 4 wt.%. The elasticising additives are added, for example, to the adhesive, e.g. B. melamine resin, is added before application to the chips and applied to the chips together with the adhesive. Preferably, the elasticizing agent is applied to the chips before or, more preferably, after the adhesive.

As described above, a first and a second, and possibly more components are used in combination as an adhesive. It is preferred if the adhesive predominantly comprises a first component, in particular melamine resin. It is further preferred if the proportion of the first component in the total use of the adhesive exceeds 15% by weight, in particular 20% by weight. The first component and the second component of the adhesive can be adjusted continuously within a wide range depending on the requirements of the chipboard. In the case of a multi-layer board structure, this preferably applies to both the middle layer and the other layers. They are preferably applied to the chips in a ratio of 2:1, preferably 3:1, particularly preferably 4:1 or 5:1 from first component to second component or in a ratio between these values. If the chipboard according to the invention has cover layers, a higher proportion of the first component of the adhesive is preferably used compared to the middle layer.

Particularly preferably, the chips or chip cake are pressed into a chipboard with an odd number of layers, whereby the layers differ in particular in terms of different chip sizes. For example, the chipboard has three or five layers on top of each other. In a chipboard with three layers, for example, a middle layer is arranged between two cover layers. The middle layer typically consists of a proportion of at least 30% by weight, preferably at least 45% by weight, particularly preferably at least 60% by weight of a pressed chipboard and usually has coarse chips. The cover layers are scattered symmetrically or asymmetrically in relation to their weight proportion and usually have fine chips. If the chipboard according to the invention consists of a single-layer structure, different chip fractions of coarse and fine chips are brought together in one layer.

One or more additives, e.g. antioxidants, light stabilizers, antistatic agents, colorants, fungicides, flame retardants, agents for adjusting the thermal or electrical conductivity, or one or more fillers can also be used to produce the chipboard according to the invention. Mineral particles, but also ceramic, synthetic or glass or plastic particles can be used as fillers. A combination of additives or fillers can also be applied to the chips, either individually or as a mixture. Fillers and/or additives can also be applied, in particular applied, in a mixture with the adhesive.

According to an advantageous embodiment of the invention, a hydrophobic agent is applied to the chips before the chip cake is pressed, in particular after the chips have been glued. Paraffin or wax, for example, are provided as hydrophobic agents, which are typically used in amounts of up to 5% by weight/dry wood, usually in amounts of up to 2% by weight/dry wood, often in an amount of 0.1% by weight/dry wood to 1% by weight/dry wood, possibly up to 1.5% by weight/dry wood. The use of hydrophobic agents helps to reduce the tendency of the chipboard to swell and to increase the moisture resistance of the chipboard.

According to an advantageous development of the invention, the chipboard is sanded after pressing. For this purpose, a sanding device with an abrasive, e.g. sandpaper and/or preferably a sanding belt, can be provided.

Sanding is usually carried out in two sanding steps, with abrasives with a grain size of 50-60 being used in the first sanding step and 80-100 in the second sanding step. The chipboard according to the invention has a harder surface compared to known chipboards according to DIN EN 312, where a coarser grain size of the abrasive is preferred. The grain size in both sanding steps is preferably a maximum of 60, preferably a maximum of 50, particularly preferably a maximum of 40.

The chipboard produced using the method described above can be adapted to different requirements using different combinations of chips, adhesives, fillers and, if necessary, other additives such as waxes. It is therefore expressly pointed out that the features described in connection with this invention can be freely combined with one another.

The particle board according to the invention is preferably waterproof and thus also moisture-resistant. It has an excellent and unusual swelling and shrinkage behavior, in which an already low swelling is additionally accompanied by a substantial regression of the swelling during subsequent drying.

The chipboard according to the invention is typically formed in the shape of a board, i.e. it generally has two main surfaces, which are also referred to below as the top and bottom. The top and bottom are spaced apart from one another by the thickness of the chipboard. The narrow surfaces of the chipboard extend between the top and bottom, each of which merges into the top and bottom at the edges. The thickness of the finished chipboard can be from 2 mm to 80 mm, typically between 3 mm and 50 mm, mostly between 3 mm and 32 mm. A typical application may require a chipboard thickness of 6 mm to 32 mm. The chipboard can have flat main surfaces; the top and/or bottom can also be embossed or milled or processed in some other way, so that the chipboard has a variable thickness in relation to the surface area of the chipboard.

The narrow surfaces of the chipboard according to the invention can be processed with conventional tools. They can be sawn, cut or milled. The chipboard can be cut to its maximum length and width as required, for example in The chipboard can be cut to length during final production. Smaller dimensions can be produced, for example, by cutting the chipboard originally produced in the press. Typical dimensions of the chipboard can be 6700 mm (length) x 2500 mm (width) after production in the press, 1380 mm × 195 mm after being divided into floor, wall or ceiling panels or 3048 mm × 2800 mm. The latter format is particularly suitable for use in construction because the width of the board corresponds to a standard floor height.

Advantageously, the chipboard according to the invention has only minimal thickness swelling, in particular in accordance with the test method described in DIN EN 317, which is less than 5%, advantageously less than 4%, preferably less than 3%, particularly preferably less than 2.5%, based on the original board thickness. It is also advantageous for an uncoated chipboard to have an edge swelling in accordance with the test method described in EN-13329 of less than 6%, preferably less than 5%, and a coated chipboard particularly preferably has an edge swelling of less than 4%. The swelling can be reduced by over 90% compared to a standard chipboard of the same thickness made from the same chip material but with less adhesive and other types of adhesive. A value of less than 5% for the edge swelling of the uncoated chipboard and of less than 4% for the edge swelling of a coated chipboard is therefore an exceptional improvement over known chipboards in accordance with DIN EN 312.

The average density of the chipboard according to the invention is preferably 800 kg/m ³ to 1,000 kg/m ³ , preferably 830 kg/m ³ to 970 kg/m ³ , particularly preferably 850 kg/m ³ to 950 kg/m ³ . It is therefore approximately 100 kg/m ³ to 300 kg/m ³ higher than known chipboards of type P2 according to DIN EN 312.

The chipboard according to the invention has very good strength properties, in particular a high transverse tensile strength, which is at least 2.5 N/mm ² , preferably up to 3 N/mm ² , in particular up to 4 N/mm ² . The chipboard preferably has an E-modulus of 3000 N/mm ² to 5000 N/mm ² , advantageously from 3500 to 5000 N/mm ² , particularly preferably from 4000 to 5000 N/mm ² . The good strength properties result in the fact that less Fasteners, e.g. screws, have to be used because the individual fasteners have a better hold in the board. The higher transverse tensile strength also allows more intensive processing of a chipboard according to the invention, e.g. milling simple profiles into the side edge of a board. For example, at least one simple profile, such as a tongue and groove profile, can be incorporated into the narrow surface of a chipboard, which aligns two interlocking boards with each other both vertically and horizontally. A high bending strength of the chipboard of at least 35 N/mm ² , preferably at least 40 N/mm ² allows it to be used as a construction element, e.g. wall stiffeners.

The invention further relates to the use of the chipboard described above for construction purposes indoors and outdoors. The chipboard according to the invention is characterized by the fact that it can be used in a variety of ways due to the minimal swelling, in particular the reduced thickness swelling in the area of the narrow surfaces. In interior construction, the chipboard can be used, for example, as a floorboard or as a floor covering, with or without a coating. In contrast to non-waterproof floorboards or floor coverings, for example, it can also be used in damp and wet rooms, in particular because the narrow surfaces, which may have an edge profile where the board is freely accessible to moisture, no longer swell significantly under the influence of water or high humidity or almost completely return to their original size when dried.

This means that, for example, a chipboard that essentially does not swell and is dimensionally stable against water or humidity and has high strength values can now be produced on known devices for the production of wood-based panels, and is not limited to narrow formats.

Of course, the chipboard according to the invention can also be used as a wall or ceiling board, as a furniture board and as a construction board, especially in the construction of damp and wet rooms or of laboratory and technical rooms or workshops, but is not limited to this. In external construction, the chipboard according to the invention is also suitable as a construction board, typically e.g. as Facade panel, for external window sills, coverings including roof coverings and wall elements.

The coated chipboard according to the invention can be used, for example, for indoor and outdoor floors. In this way, it is possible to use the same floors or floor coverings for indoor and adjacent outdoor areas (terraces, balconies, facades, access routes). The chipboard according to the invention can preferably be used for constructions, in particular furniture, indoors and outdoors. The construction of workshops, production halls or stables can, for example, be carried out without further ado using the coated chipboard according to the invention. Not only vertical, but above all horizontal surfaces can be produced, which must be waterproof or moisture-resistant. Furthermore, the coated chipboard according to the invention can also be used, for example, for fire protection elements and building elements in shipbuilding due to its water resistance, in particular if it is provided with or coated with fire protection substances and is therefore designed to be flame-retardant, for example, not only in technical areas but also in the areas used by passengers, since decorative surfaces can be designed.

The coated chipboard can optionally be designed as a panel, i.e. if required, it can be provided with a profile on at least one, usually two or four edges. The profile is preferably used to fix two panels together, usually without adhesive. Alternatively, two panels arranged next to each other can also be connected butt to butt. They can be fixed, for example, using double-sided adhesive tape that is arranged in the area to the side of a joint between the directly adjacent panels. It is also possible to glue directly adjacent panels or boards together, with a waterproof adhesive preferably being used.

The surface of the uncoated chipboard is rough and is not suitable for decorative or certain non-decorative purposes, e.g. because of the surface roughness. The care and hygienic maintenance of a rough surface is hardly possible. There is no information available from the state of the art on Coatability of a waterproof chipboard. Surprisingly, it turns out that the waterproof chipboard can be coated in a variety of ways:
The waterproof chipboard can be provided with a single or multi-layer coating applied at least in sections. The coating is applied to at least one section of the surface of the waterproof chipboard, typically on one side and/or edge. Preferably, a coating is applied to the top and/or bottom of the chipboard.

The coating can have one or more layers, which for example comprise synthetic resin, varnish, paper, in particular synthetic resin-impregnated paper, veneer, foil, in particular metal or plastic foil, cork, felt and/or laminate. If paper, in particular synthetic resin-impregnated paper, is used, this can be, for example, an overlay without decoration, a decorative paper, an underlay or a counter-pull paper. These synthetic resin-impregnated papers are characterized by the fact that the synthetic resin with which they are impregnated is dry but still chemically reactive, i.e. not yet hardened. A combination of at least one decorative paper and an overlay is preferably used. Melamine formaldehyde resin and/or urea resin can typically be used as the synthetic resin. Alternatively, it can also be laminate made from a plurality of synthetic resin-impregnated papers that are pressed together, whereby the synthetic resin, typically melamine and/or urea, is hardened, which is why the laminate is also listed separately in the coatings.

The coating can have several layers of the same material. However, it can also comprise several layers of two or more of the aforementioned materials. Typical combinations of layers include, for example, synthetic resin, paper and varnish, laminate and varnish, veneer and varnish, paper or veneer and varnish. The coating can be applied in solid or liquid form, e.g. in the case of synthetic resin or varnish. The coating can be applied to the surface of the waterproof chipboard to be coated by spraying, pouring, rolling, doctoring or nozzles, for example. Flat coatings such as paper, laminate, film or veneer are placed on the surface of the waterproof chipboard to be coated.

The coating can be designed with a decoration. In addition to or as an alternative to a decoration, it can have a structure, i.e. a three-dimensionally designed surface. The structure is preferably adapted to the decoration (embossed in register).

The coating can be fixed to the waterproof chipboard with an adhesive. Hot melt adhesives, also known as hot melts, are often used as adhesives. Typical hot melt adhesives include polyvinyl acetate (PVAc), polyamide resins, saturated polyesters, ethylene-vinyl acetate copolymers (EVA), polyolefins, block copolymers (e.g. styrene-butadiene-styrene or styrene-isoprene-styrene) and polyimides. Polyvinyl acetate, ethylene-vinyl acetate copolymers and polyolefins are particularly suitable for fixing a coating. The adhesives used to apply the coating or as a coating, e.g. hot melts, are not identical to the adhesives used to produce the waterproof chipboard.

Alternatively, the coating can be applied directly to the waterproof chipboard, particularly if synthetic resins or varnishes are applied. The coating is preferably applied to the waterproof chipboard by pressing, possibly at an elevated temperature. Alternatively, coatings can be cured by drying or heating, e.g. with infrared or ultraviolet radiation or with electron beams. The chipboard with the coating already applied but not yet fixed can be pressed directly or exposed to radiation. If a flat coating is applied, it is advantageous to produce a stack of pressed products in which the coating and the waterproof chipboard are stacked on top of each other in order to then be pressed, for example.

The coating can be supplemented by additional layers, which are usually not arranged on the outside. Such additional layers can be: a primer, a base coat, or one or more layers containing corundum, glass particles, plastic particles and/or metal particles.

Fig. 1

eine schematische Darstellung des Querschnitts einer beschichteten wasserfesten Spanplatte mit einer Beschichtung aus kunstharzgetränktem Papier auf der Oberseite;

Fig. 2

eine schematische Darstellung des Querschnitts einer beschichteten wasserfesten Spanplatte mit einer Beschichtung aus kunstharzgetränktem Papier auf der Oberseite und der Unterseite;

Fig.3

eine schematische Darstellung des Querschnitts einer beschichteten wasserfesten Spanplatte mit einer aufkaschierten Beschichtung aus Schichtstoff

In the following, embodiments of the invention are described with reference to drawings explained in more detail. Here:

Fig.1

a schematic representation of the cross-section of a coated waterproof chipboard with a coating of resin-impregnated paper on the top side;

Fig.2

a schematic representation of the cross-section of a coated waterproof chipboard with a coating of resin-impregnated paper on the top and bottom sides;

Fig.3

a schematic representation of the cross-section of a coated waterproof chipboard with a laminated coating

For all of the following examples, a three-layer waterproof chipboard with an adhesive content of more than 12% by weight is used, preferably with an adhesive content of 25% by weight in the two outer cover layers and 30% by weight in the middle layer, which is located between the outer cover layers. In addition to a higher bulk density of approx. 880 kg/m ³ compared to a normal chipboard (approx. 720 kg/m ³ ), this waterproof chipboard also has a significantly lower swelling of 2% to 3% compared to a swelling of 28% for a standard chipboard, such as that classified as P2 according to DIN EN 312:2010. Such standard P2 chipboards are used, for example, as furniture boards. The swelling was measured according to DIN EN 317.

The edge swelling, which is measured here on the coated board in accordance with DIN EN 13329, cannot be measured for a standard chipboard with an adhesive content of less than 12% by weight/dry chipboard; it is too high. In contrast, for the waterproof chipboard used in the invention with an adhesive content of more than 12% by weight/dry chipboard, the edge swelling is only 3% to 4%. Waterproof chipboards of various dimensions are used. In the following examples, the top and possibly the bottom are usually coated, optionally also an edge of a waterproof chipboard.

As far as adhesive is used in connection with the coating of the waterproof chipboard, this adhesive is also referred to as "synthetic resin", especially in connection with the embodiments.

Example 1: Carrier plate pressed with paper structure

On the top side 1a of a waterproof chipboard 1 (format: (length x width x thickness) 2800 × 2070 × 22 mm) is applied according to Fig.1 a decorative paper 2 and an overlay 3 are placed on top of it. An optionally used counter-sheet 4 is placed under the underside 1b of the chipboard 1 if necessary and this stack of pressed material consisting of three or four layers is pressed in a short-cycle press. Overlay 3, decorative paper 1 and the optionally used counter-sheet 4 are each used as synthetic resin-impregnated papers, which are described in more detail below. The result is a coated, waterproof chipboard 1 that has a higher impact resistance than a similarly coated standard chipboard P2, such as that used as a furniture board. The waterproof chipboard coated according to this example can be used in areas subject to high mechanical stress (horizontal applications). A test of the impact resistance according to DIN EN 14323-07/2017, Section 5.13 with the large ball gave a value of 1600 mm. A test of a standard chipboard P2 with the same coating gave a value of 1200 mm. Both boards, the waterproof chipboard used according to the invention as well as the standard chipboard P2, achieved class 4 (> 350 revolutions) in terms of abrasion resistance, measured according to DIN EN 14322 - as of February 2022.

• ein Dekorrohpapier mit einem Gewicht von 50 bis 90 g/m², mit
• einer vor oder nach dem Bedrucken durchgeführten Imprägnierung mit Kunstharz, hier z. B. auf der Basis von Harnstoff- oder Melaminharz oder einem Gemisch der beiden Harze, wobei das Kunstharz flüssig oder als Feststoff, insbesondere pulverförmig aufgebracht wird. Anschließend wird das Kunstharz getrocknet, aber noch nicht ausgehärtet. Das Kunstharz ist also chemisch noch nicht bis zu Ende reagiert bzw. polymerisiert. Es ist aber nach dem Trocknen nicht mehr klebrig. Das Kunstharz wird in einer Menge von 60 g/m² bis 110 g/m² eingesetzt. Das Gesamtgewicht des kunstharzimprägnierten Papiers ergibt sich hier und auch in den weiteren Angaben dieser Beschreibung aus dem Gewicht des Papiers und dem Gewicht des eingesetzten Kunstharzes, gemessen nach der Trocknung und vor dem Aushärten des Kunstharzes.

For the embodiment 1, a decorative paper is used, i.e. a synthetic resin-impregnated paper with a total weight of 110 to 200 g/m ² , comprising

• a decorative base paper with a weight of 50 to 90 g/m ² , with
• an impregnation with synthetic resin before or after printing, here e.g. based on urea or melamine resin or a mixture of the two resins, whereby the synthetic resin is applied in liquid or solid form, especially in powder form. The synthetic resin is then dried but not yet hardened. The Synthetic resin has not yet fully reacted or polymerized chemically. However, it is no longer sticky after drying. The synthetic resin is used in quantities of 60 g/m ² to 110 g/m ^2. The total weight of the synthetic resin-impregnated paper is determined here and in the other details of this description from the weight of the paper and the weight of the synthetic resin used, measured after drying and before the synthetic resin hardens.

• einem Rohpapier mit einem Gewicht von 25 g/m² bis 50 g/m²
• einer Imprägnierung mit Kunstharz auf Basis von Melaminharz, das wässrig oder als Feststoff, insbesondere pulverförmig aufgebracht wird, und dass nach der Trocknung einem Gewicht von 85 g/m² bis 320 g/m² vorliegt.

Furthermore, an overlay, also a resin-impregnated paper, with a total weight of 120 to 400 g/m ² is used, based on

• a base paper with a weight of 25 g/m ² to 50 g/m ²
• an impregnation with synthetic resin based on melamine resin, which is applied in aqueous or solid form, in particular in powder form, and which, after drying, has a weight of 85 g/m ² to 320 g/m ² .

• einem Rohpapier mit einem Gewicht von 70 g/m² bis 120 g/m²
• einer Imprägnierung mit Kunstharz, hier z. B. auf Basis von Harnstoff- und/oder Melaminharz oder Gemischen aus den beiden Harzen, welche wässrig oder als Feststoff, insbesondere pulverförmig aufgebracht wird. Das Kunstharz wird in einer Menge von 80 g/m² bis 120 g/m² eingesetzt, gemessen nach der Trocknung, aber vor dem Aushärten.

Finally, an optional backing is used as a resin-impregnated paper with a total weight of 150 g/m ² to 240 g/m ² , based on

• a base paper with a weight of 70 g/m ² to 120 g/m ²
• an impregnation with synthetic resin, here e.g. based on urea and/or melamine resin or mixtures of the two resins, which is applied in aqueous or solid form, especially in powder form. The synthetic resin is used in an amount of 80 g/m ² to 120 g/m ² , measured after drying but before hardening.

The paper is impregnated with synthetic resin by either pulling the paper through an impregnation bath with liquid synthetic resin, whereby the paper is impregnated with the synthetic resin or synthetic resin mixture and after passing through the bath, excess synthetic resin is removed, e.g. by stripping it off. The paper impregnated in this way is then dried, whereby care is taken to ensure that the synthetic resin does not react completely, i.e. harden. After drying, impregnated materials usually have a residual moisture content (VC = volatile compounds) of VC 5% to 6%. Alternatively or Optionally, after impregnating the paper with liquid synthetic resin, powdered synthetic resin is applied to the paper, usually by sprinkling. When synthetic resin-impregnated paper is mentioned in connection with this invention, this means paper that has been impregnated with synthetic resin, for example, as described above.

• unter Wirkung von erhöhtem Druck mind. 25 kg/cm² und erhöhter Temperatur von z. B. 200 °C
• und einer Presszeit von 6 Sekunden bis 30 Sekunden
• optional unter Ausbildung einer Oberflächenstruktur, die ggf. auf das Dekor angepasst ist (sogenanntes "embossed in register") ein Laminat hergestellt wird.

The further production of the coating on the waterproof chipboard 1 is carried out by producing a pressed material stack which - from top to bottom - has the overlay 3 as synthetic resin-impregnated paper, the decorative paper 2 as synthetic resin-impregnated paper, the waterproof chipboard 1 and optionally the counter-sheet 4 as synthetic resin-impregnated paper. The pressed material stack is then pressed into a laminate in a short-cycle hot press, wherein the short-cycle press has an upper press plate which acts on the overlay 3, and wherein

• under the effect of increased pressure of at least 25 kg/cm ² and increased temperature of e.g. 200 °C
• and a pressing time of 6 seconds to 30 seconds
• Optionally, a laminate is produced with the formation of a surface structure that may be adapted to the decor (so-called "embossed in register").

The stack of pressed material is heated in the press to such an extent that the synthetic resin is first liquefied and then chemically hardens, solidifying as it cools after the press. In example 1, the structure is embossed into the liquefying synthetic resin and fixed by the hardening of the synthetic resin. Embossing the surface is typical when using synthetic resin-impregnated paper, varnish, veneer or foils, especially metal or plastic foils.

Further optionally, a single or multi-layer lacquer layer can be applied to the overlay 3 after pressing, in particular to adjust surface properties such as gloss, high gloss or mattness of the surface or to create anti-fingerprint properties. The lacquer is preferably applied as a UV lacquer, e.g. as an acrylic lacquer or as a urethane lacquer, typically as a UV or radiation-curing lacquer, usually in two to three layers, with preference being given to multi-layer After applying each coat of paint, the previously applied layer is gelled. After applying the last coat of paint, the coats of paint are completely cured. The adhesion of the coat of paint to the overlay 3 can optionally be improved by applying a primer to the overlay 3 before the paint is applied.

Embodiment 1 thus describes a waterproof chipboard 1, onto which a two-layer coating, each consisting of one layer of synthetic resin-impregnated paper, is applied to the top side 1a of the chipboard 1. A synthetic resin-impregnated paper can optionally also be applied to the bottom side 1b. According to a further variant of this embodiment, one or more layers of varnish can be applied to the synthetic resin-impregnated paper on the top side 1a, if necessary after applying a primer that improves the adhesion of the varnish to the synthetic resin-impregnated paper.

The surface coating improves the usability of the waterproof chipboard 1. The coating creates a smooth and highly stable surface, apart from any structure that may be applied. This makes the surface of the top side 1a easier to maintain and better protected against external influences. In addition, edge swelling is minimal.

Implementation example 2: Carrier plate pressed with paper structure

On waterproof chipboard 1 (format: 2800 × 2070 × 25 mm) is applied according to Fig.2 A decorative paper 2 and an overlay 2 are placed on both sides of the top side 1a and bottom side 1b and this stack of five layers is pressed in a short-cycle press. Overlay 3 and decorative paper 2 are each used as synthetic resin-impregnated papers. This creates a coated, waterproof chipboard 1 that has a higher impact resistance and a lower swelling than an identical structure with a standard chipboard P2. The waterproof chipboard 1 produced according to the invention and coated on both sides can be used in areas subject to high mechanical and hygrological stress (vertical applications). This can be, for example, the construction of bathroom or kitchen furniture or the construction of kitchens, toilet facilities and of changing rooms in wet areas or the interior fittings of ships, especially if the waterproof chipboard is also flame-retardant. A test of the impact resistance according to DIN EN 14323-07/2017, Section 5.13 with the large ball resulted in a value of 1600 mm. A test of a standard chipboard P2 with the same coating resulted in a value of 1200 mm. Both boards achieved class 4 (> 350 revolutions) in terms of abrasion resistance.

• einem Dekorrohpapier mit einem Gewicht von 50 bis 90 g/m², mit
• eine vor oder nach dem Bedrucken durchgeführte Imprägnierung mit Kunstharz, z. B. auf der Basis von Harnstoff- oder Melaminharz oder einem Gemisch der beiden Harze, wobei das Kunstharz flüssig oder als Feststoff, insbesondere pulverförmig aufgebracht wird. Anschließend wird das Kunstharz getrocknet, aber noch nicht ausgehärtet, bis es mit einem Gewicht von 60 g/m² bis 110 g/m² vorliegt.

For the embodiment 2, an upper and a lower decorative paper 2 is used as a synthetic resin-impregnated paper with a total weight of 110 to 200 g/m ² , based on

• a decorative base paper with a weight of 50 to 90 g/m ² , with
• impregnation with synthetic resin, e.g. based on urea or melamine resin or a mixture of the two resins, before or after printing, whereby the synthetic resin is applied in liquid or solid form, particularly in powder form. The synthetic resin is then dried, but not yet hardened, until it has a weight of 60 g/m ² to 110 g/m ² .

• einem Rohpapier mit einem Gewicht von 25 g/m² bis 50 g/m²
• einer Imprägnierung mit Kunstharz, z. B. auf Basis von Melaminharz, das wässrig oder als Feststoff, insbesondere pulverförmig aufgebracht wird, und dass nach der Trocknung mit einem Gewicht von 85 g/m² bis 320 g/m² vorliegt.

Furthermore, an upper and a lower overlay 3 is used as a resin-impregnated paper with a total weight of 120 to 400 g/m ² , based on

• a base paper with a weight of 25 g/m ² to 50 g/m ²
• an impregnation with synthetic resin, e.g. based on melamine resin, which is applied in aqueous or solid form, in particular in powder form, and which, after drying, has a weight of 85 g/m ² to 320 g/m ² .

• unter Wirkung von erhöhtem Druck mind. 25 kg/cm² und erhöhter Temperatur von z. B. 200 °C
• und einer Presszeit von 6 Sekunden bis 30 Sekunden
• optional unter Ausbildung einer Oberflächenstruktur, die ggf. auf das Dekor angepasst ist (sogenanntes "embossed in register") ein Laminat hergestellt wird.

The further production of the coating on the waterproof chipboard 1 is carried out by producing a pressed material stack which has the upper overlay 3 as synthetic resin-impregnated paper, the upper decorative paper 2 as synthetic resin-impregnated paper and the waterproof chipboard 1 as well as the lower decorative paper 2 and the lower overlay 3 from above and below. The pressed material stack consisting of five layers is pressed in a short-cycle hot press pressed into a laminate, wherein the short-cycle press has an upper press plate that acts on the upper overlay 3, and wherein

• under the effect of increased pressure of at least 25 kg/cm ² and increased temperature of e.g. 200 °C
• and a pressing time of 6 seconds to 30 seconds
• Optionally, a laminate is produced with the formation of a surface structure that may be adapted to the decor (so-called "embossed in register").

The waterproof chipboard 1 produced in this way, coated on both sides, can be used in particular in vertical applications, e.g. room dividers or cupboard walls. It is particularly strong and - unlike standard chipboard P2 - can be used in damp and wet rooms or in difficult climatic conditions, e.g. areas with high humidity such as bathrooms or saunas, laundries or car washes.

Example 3: Laminating CPL/HPL

A waterproof chipboard 1 (format: 2800 × 600 × 28/ 38 mm) is coated according to Fig.3 with a profile 5 milled on one edge, here for example designed as a curve towards the underside 1b. Such a chipboard 1 is also referred to as a strand and is used, for example, as a worktop in kitchens, workshops or laboratories.

A thin laminate (continuous pressure laminate CPL or high pressure laminate HPL) with a thickness of 0.5 mm is glued to the top side 1a and a counter layer 4 is glued to the bottom side 1b using an adhesive 6, e.g. a hot melt adhesive. The thin laminate 7 consists of an overlay, a decorative paper and several backing papers that are arranged under the decorative paper. The decorative paper and the overlay are each impregnated with melamine resin. The backing papers are impregnated with either a melamine/phenolic mixed resin (when using CPL) or a phenolic resin (when using HPL). These thin laminates 7 were produced either on a continuous press (CPL) or a multi-layer press (HPL). The order quantity of the hot melt is approx. 100 g/m ² .

As a counter layer 4, either a thin laminate 7, alternatively a plastic film or a paper is used on the underside 1b of the waterproof chipboard 1, which is glued to the chipboard 1 with the same amount of adhesive as the thin laminate 7.

The pressing takes place in a laminating press at approx. 120°C, 300 N/cm ² and a pressing time of approx. 1 second, whereby in a first pressing step the counter-pull 4 and then in a second pressing step the thin laminate 7 are glued to the underside 1b and the top side 1a of the chipboard 1.

After the adhesive has cooled, the thin laminate 7 glued to the top side 1a of the chipboard 1 is fixed to the milled edge by applying a PVAc adhesive to the profiled edge on a postforming device, the thin laminate 7 is deformed around the milled profile 5 and fixed to the edge using the PVAc adhesive. In this embodiment, the top side 1a, bottom side 1b and one edge of the waterproof chipboard 1 are coated.

An impact resistance test was carried out on this waterproof chipboard 1 and a comparison sample with a standard chipboard P2 coated with a 0.8 mm thick laminate in accordance with DIN EN 438-2019-03, Part 2 Test 20. The laminated laminate 7 on the waterproof chipboard 1 also achieved an impact resistance value of 22 N despite its significantly lower thickness (0.5 mm vs. 0.8 mm). In addition, the surface stability in the postforming area of the waterproof chipboard 1 was also significantly better due to the higher bulk density. Furthermore, narrower postforming radii can apparently be achieved with a thinner laminate. This significantly expands the design options and, accordingly, the possible uses of a waterproof chipboard 1 coated with a laminate compared to a standard chipboard P2 coated in the same way.

Example 4: Carrier plate floor pressed with paper structure

A decorative paper 2 and an overlay 3 (e.g. an overlay for use class 34 according to DIN EN 13329) are placed on the top side 1a of a waterproof chipboard 1 (format: 2800 × 2070 × 10 mm); an optionally used counter-sheet 4 is placed under the bottom side 1a of the chipboard 1. The structure corresponds to the schematic representation in Fig.1 This stack of four layers is pressed in a short-cycle press. Overlay 3, decorative paper 2 and the optionally used counter-sheet 4 are each used as resin-impregnated papers.

The result is a coated waterproof chipboard 1 that has a higher impact resistance than an identical structure with an equally coated standard chipboard P2. A test of the impact resistance according to DIN EN 14323-07/2017, section 5.13 with the large ball resulted in a value of 1800 mm. A test of a standard chipboard P2 with the same coating resulted in a value of 1200 mm. Both boards achieved service class 34 in terms of abrasion resistance (DIN EN 13329: Laminate flooring - Elements with a top layer based on aminoplastic, thermosetting resins, 08-2016)

• einem Dekorrohpapier mit einem Gewicht von 50 bis 90 g/m², mit
• eine vor oder nach dem Bedrucken durchgeführte Imprägnierung mit Kunstharz z. B. auf der Basis von Harnstoff- oder Melaminharz oder einem Gemisch der beiden Harze, wobei das Kunstharz flüssig oder als Feststoff, insbesondere pulverförmig aufgebracht wird. Anschließend wird das Kunstharz getrocknet, aber noch nicht ausgehärtet, bis es mit einem Gewicht von 60 g/m² bis 110 g/m² vorliegt.

For the embodiment 4, a decorative paper 2 is used as a synthetic resin-impregnated paper with a total weight of 110 to 200 g/m ² , based on

• a decorative base paper with a weight of 50 to 90 g/m ² , with
• impregnation with synthetic resin, e.g. based on urea or melamine resin or a mixture of the two resins, before or after printing, whereby the synthetic resin is applied in liquid or solid form, particularly in powder form. The synthetic resin is then dried, but not yet hardened, until it has a weight of 60 g/m ² to 110 g/m ² .

• einem Rohpapier mit einem Gewicht von 25 g/m² bis 50 g/m²
• einer Imprägnierung mit Kunstharz, z. B. auf Basis von Melaminharz, das wässrig oder als Feststoff, insbesondere pulverförmig aufgebracht wird, und dass nach der Trocknung mit einem Gewicht von 85 g/m² bis 320 g/m² vorliegt, sowie
• optional einem Korundgehalt von ca. 30 g/m², welcher entweder durch Zugabe zu dem zum Imprägnieren verwendeten Kunstharz oder durch Aufstreuen auf das auf das Papier aufgebrachte Kunstharz während oder nach dem Imprägnierprozess eingebracht wurde. Korund muss eingesetzt werden, wenn die Nutzungsklasse 34 erreicht werden soll.

Furthermore, an overlay 3 is used as a resin-impregnated paper with a total weight of 120 to 400 g/m ² , based on

• a base paper with a weight of 25 g/m ² to 50 g/m ²
• an impregnation with synthetic resin, e.g. based on melamine resin, which is applied in aqueous or solid form, especially in powder form and that after drying it has a weight of 85 g/m ² to 320 g/m ² , and
• optionally a corundum content of approx. 30 g/m ² , which was introduced either by adding it to the synthetic resin used for impregnation or by sprinkling it onto the synthetic resin applied to the paper during or after the impregnation process. Corundum must be used if service class 34 is to be achieved.

• einem Rohpapier mit einem Gewicht von 70 g/m² bis 120 g/m²
• einer Imprägnierung mit Kunstharz, z. B. auf Basis von Harnstoff- und/oder Melaminharz oder Gemischen aus den beiden Harzen, welche wässrig oder als Feststoff, insbesondere pulverförmig aufgebracht wird und anschließend, ggf. nach einer Trocknung mit einem Gewicht von 80 bis 120 g/m² vorliegt.

Finally, an optional countercoat 4 is used as a resin-impregnated paper with a total weight of 150 g/m ² to 240 g/m ² , based on

• a base paper with a weight of 70 g/m ² to 120 g/m ²
• an impregnation with synthetic resin, e.g. based on urea and/or melamine resin or mixtures of the two resins, which is applied in aqueous or solid form, in particular in powder form and then, if necessary after drying, has a weight of 80 to 120 g/m ² .

• unter Wirkung von erhöhtem Druck mind. 25 kg/cm² und erhöhter Temperatur z. B. von 200 °C
• und einer Presszeit von 6 Sekunden bis 30 Sekunden
• optional unter Ausbildung einer Oberflächenstruktur, die ggf. auf das Dekor angepasst ist (sogenanntes "embossed in register") ein Laminat hergestellt wird.

The further production of the coating on the waterproof chipboard 1 is carried out by producing a stack of pressed material, which from top to bottom has the overlay 3 as synthetic resin-impregnated paper, possibly with the addition of corundum, the decorative paper 2 as synthetic resin-impregnated paper, the waterproof chipboard 1 and optionally the counter-sheet 4 as synthetic resin-impregnated paper. The stack of pressed material is pressed into a laminate in a short-cycle hot press, whereby the short-cycle press has an upper press plate that acts on the overlay, and whereby

• under the effect of increased pressure of at least 25 kg/cm ² and increased temperature, e.g. 200 °C
• and a pressing time of 6 seconds to 30 seconds
• Optionally, a laminate is produced with the formation of a surface structure that may be adapted to the decor (so-called "embossed in register").

Optionally, overlay 3, in which a structure may be embossed, can be printed with a or multi-layered lacquer layer can be applied, in particular to adjust surface properties such as gloss, high gloss or mattness of the surface or to create anti-fingerprint properties. The lacquer is preferably applied as a UV lacquer or radiation-curing lacquer, e.g. as a lacquer based on acrylates and/or methacrylates, usually in two to three layers, whereby in the case of multi-layered lacquer application, after the application of each lacquer layer, the layer already applied is preferably gelled. After the last lacquer layer has been applied, the lacquer layers are completely cured. The adhesion of the lacquer layer to the overlay can optionally be improved by applying a primer to the overlay before the lacquer is applied.

After coating, smaller panels, so-called raw fixed dimensions, are produced from the waterproof chipboard 1 using a multi-blade saw, which are then provided with a profile on the edges that can be connected without glue, so that the panels can be used as floor elements or as wall or ceiling elements. In comparison to a standard chipboard P2, the laminate floor produced according to this example, which was made with the waterproof chipboard 1, shows a significantly better milling pattern.

The floor panels made from the coated waterproof chipboard 1 can - unlike those made from standard chipboard P2 - also be used in humid environments due to the dimensional stability resulting from the largely reduced swelling behavior.

Example 5: Carrier plate with liquid overlay including decorative direct printing

Using a thin waterproof chipboard 1 (format: 2800 × 2070 × 10 mm), a floor panel with a liquid-applied synthetic resin coating is produced (DIN EN 15668: Laminate flooring - Directly printed elements with synthetic resin top layer, 11-2021). The waterproof chipboard 1 is coated with liquid synthetic resin, whereby a primer is first applied to the chipboard and a decor is then applied to this primer using direct printing. The direct printing is then covered with at least two liquid-applied layers made of synthetic resin, whereby corundum is optionally introduced into a non-external layer of synthetic resin, e.g. by sprinkling or jetting. The corundum can also be mixed into the liquid synthetic resin.

• Grundieren der Oberseite der wasserfesten Spanplatte mit Hilfe eines als Grundierung flüssig aufgetragenen Kunstharzes, z. B. eines Melaminharzes, eines Harnstoffharzes oder eines Gemisches der beiden Kunstharze in einer Menge von ca. 20 g/m² bis 30 g /m² (Feststoffgehalt: Melaminharz: ca. 65 Gew%, Harnstoffharz: ca. 50 Gew%). Der Auftrag erfolgt über Walzen.
• Trocknen des Harzes mit Hilfe einer Trocknungsvorrichtung, z. B. eines Umlufttrockners oder von IR-Strahlern auf einen Feuchtegehalt der Grundierung von ca. 20 %.
• Optional: Mehrfaches Auftragen von Farbgrundierung (z. B. Gemisch aus Pigmenten und Bindemittel wie Kasein oder Maisprotein) in flüssiger Form in einer Menge von 5 g/m² bis 10 g/m² (Feststoffgehalt: ca. 50 Gew%) mit Zwischentrocknung durch eine Trocknungsvorrichtung, z. B. durch Umluft oder IR-Strahler. Üblich ist ein Auftragen von zwei bis sechs Schichten der Farbgrundierung. Der Auftrag der Farbgrundierung erfolgt ebenfalls über Walzenauftrag. Dabei ist die Verwendung von Weißpigmenten (Titandioxid, Calciumcarbonat, Bariumsulfat) bevorzugt.
• Optional: Auftrag eines flüssigen Primers, z. B. eines Isocyanat-Primers in einer Menge von ca. 10 g/m² bis 20 g/m² zur Verbesserung der Haftung der nachfolgend aufzutragenden Schichten. Der Primer wird getrocknet durch Umlufttrockner oder IR-Strahler. Es wird wiederum mit einem Walzenauftrag gearbeitet.
• Bedrucken der ggf. durch den Primer in ihrer Haftfähigkeit verbesserten Oberseite der wasserfesten Spanplatte, entweder analog, z. B. mittels Walze oder digital, z. B. mit Tintenstrahldrucker mit wasserbasierten Tinten, anschließend, sofern erforderlich, Trocknen der Tinte mit einer Trocknungsvorrichtung, z. B. mittels Umlufttrockner.
• Aufbringen einer Versiegelung mittels Walzenauftrag, wobei die flüssige Versiegelung aus einem Kunstharz, bevorzugt aus Melaminharz (Feststoffgehalt ca. 65 Gew.-%) und optional darin eingemischten Glaskugeln (Durchmesser Glaskugeln: 70 µm bis 90 µm) besteht. Die Auftragsmenge des Kunstharzes liegt bei 20 g/m² -30 g/m² Darin sind 10 Ges.-% bis 20 Gew.-% Glaskugeln enthalten, bezogen auf die Menge des flüssigen Kunstharzes. Anschließend erfolgt das
• Trocknen, jedoch nicht Aushärten des Kunstharzes über Umlufttrockner oder mittels IR-Strahler, gefolgt vom Abkühlen und Zwischenlagern.
• Aufbringen eines flüssigen Kunstharzes, z. B. eines Melaminharzes im Walzenauftrag in einer Menge von ca. 60 g/m² bis 80 g/m² (Feststoffgehalt ca. 65 Gew%) auf die bedruckte und bereits durch eine Schicht Kunstharz versiegelte Seite der Platte.
• Optional: Aufstreuen von Korund auf das nicht getrocknete, flüssige Melaminharz mit Hilfe einer Streuvorrichtung. Das Korund hat eine Körnung von F180 bis F240 gemäß FEPA-Standard. Die Menge beträgt meist zwischen 20 g/m² und 50 g/m² Korund, je nach gewünschter Verschleißfestigkeit.
• Mehrfachauftrag (bevorzugt bis zu 5 Schichten) eines Kunstharzes, z. B. von Melaminharz auf die Oberseite der Platte in einer Menge von 20 g/m² bis 40 g/m², wobei das Melaminharz den vorstehend angegebenen Feststoffgehalt aufweist. Beim Auftragen der letzten Schichten werden dem Kunstharz optional Glaskugeln (Durchmesser: 70 bis 90 µm) zugegeben, auch hier wieder in einer Menge von 10 Gew.-% bis 20 Gew.-% bezogen auf die Menge des flüssigen Kunstharzes. Nach jedem Auftrag erfolgt eine Zwischentrocknung mit einer Trocknungsvorrichtung, z. B. mit Hilfe von Umlufttrocknern oder mittels IR-Strahlern.
• Entsprechend zu den Beschichtungen auf der Oberseite kann optional auch der Auftrag eines flüssigen Kunstharzes, z. B. eines Melaminharzes auf der Rückseite der Spanplatte erfolgen. Dies kann ebenfalls mit einem Walzenauftragswerk erfolgen und der Auftrag des flüssigen Kunstharzes kann z. B. eine Gesamtmenge von 100 g/m² bis 140 g/m² erreichen. Das Melaminharz weist den üblichen, vorstehend angegebenen Feststoffgehalt auf. Zusätzlich kann noch Farbstoff oder Pigment im Kunstharz enthalten sein. Auch hier ist eine Zwischentrocknung durchzuführen, entweder mittels Umlufttrockner oder mittels IR-Strahler.
• Abschließend wird die ein- oder beidseitig beschichtete wasserfeste Spanplatte mit der getrockneten, aber noch nicht ausgehärteten Beschichtung in einer Kurztakt-Heißpresse wie bereits zum Ausführungsbeispiel 1 beschrieben, zu einem Laminat mit ausgehärtetem Kunstharz verpresst
  • unter Wirkung von erhöhtem Druck mind. 25 kg/cm² und erhöhter Temperatur von 200 °C
  • und einer Presszeit von 6 bis 30 s
  • optional unter Ausbildung einer Oberflächenstruktur oberhalb des Dekors; ggf. aufeinander angepasst, als so genanntes "embossed in register."

The waterproof chipboard 1 coated in this way is cured in a short-cycle press (KT press). In detail, the coating of the embodiment 5 is applied as follows:

• Priming the top of the waterproof chipboard using a synthetic resin applied as a liquid primer, e.g. a melamine resin, a urea resin or a mixture of the two synthetic resins in a quantity of approx. 20 g/m ² to 30 g/m ² (solids content: melamine resin: approx. 65% by weight, urea resin: approx. 50% by weight). The application is carried out using rollers.
• Dry the resin using a drying device, e.g. a circulating air dryer or IR radiators, to a moisture content of the primer of approx. 20%.
• Optional: Multiple applications of color primer (e.g. mixture of pigments and binding agents such as casein or corn protein) in liquid form in an amount of 5 g/m ² to 10 g/m ² (solids content: approx. 50% by weight) with intermediate drying using a drying device, e.g. using circulating air or IR radiators. It is usual to apply two to six layers of the color primer. The color primer is also applied using a roller. The use of white pigments (titanium dioxide, calcium carbonate, barium sulfate) is preferred.
• Optional: Application of a liquid primer, e.g. an isocyanate primer in a quantity of approx. 10 g/m ² to 20 g/m ² to improve the adhesion of the subsequent layers. The primer is dried using a circulating air dryer or IR radiator. The application is again carried out using a roller.
• Printing on the top side of the waterproof chipboard, which may have its adhesion improved by the primer, either analogue, e.g. using a roller, or digitally, e.g. using an inkjet printer with water-based inks, then, If necessary, dry the ink using a drying device, e.g. a circulating air dryer.
• Applying a sealant using a roller application, whereby the liquid sealant consists of a synthetic resin, preferably melamine resin (solids content approx. 65 wt.%) and optionally mixed glass beads (diameter of glass beads: 70 µm to 90 µm). The amount of synthetic resin applied is 20 g/m ² -30 g/m ² This contains 10 wt.% to 20 wt.% glass beads, based on the amount of liquid synthetic resin. The
• Drying, but not curing, the synthetic resin using a circulating air dryer or IR radiator, followed by cooling and intermediate storage.
• Application of a liquid synthetic resin, e.g. a melamine resin, by roller application in an amount of approximately 60 g/m ² to 80 g/m ² (solids content approximately 65% by weight) to the printed side of the board which has already been sealed with a layer of synthetic resin.
• Optional: Sprinkling corundum onto the non-dried, liquid melamine resin using a sprinkling device. The corundum has a grain size of F180 to F240 according to FEPA standards. The amount is usually between 20 g/m ² and 50 g/m ² of corundum, depending on the desired wear resistance.
• Multiple application (preferably up to 5 layers) of a synthetic resin, e.g. melamine resin, to the top of the board in an amount of 20 g/m ² to 40 g/m ² , the melamine resin having the solids content specified above. When applying the last layers, glass beads (diameter: 70 to 90 µm) are optionally added to the synthetic resin, again in an amount of 10 wt.% to 20 wt.% based on the amount of liquid synthetic resin. After each application, intermediate drying takes place using a drying device, e.g. using circulating air dryers or IR radiators.
• In accordance with the coatings on the top side, the application of a liquid synthetic resin, e.g. a melamine resin, can also be optionally carried out on the back of the chipboard. This can also be done with a roller applicator and the application of the liquid synthetic resin can reach a total amount of e.g. 100 g/m ² to 140 g/m ^2. The melamine resin has the usual solids content stated above. The synthetic resin may also contain dye or pigment. Here too, intermediate drying must be carried out, either using a circulating air dryer or using an IR radiator.
• Finally, the waterproof chipboard coated on one or both sides with the dried but not yet cured coating is pressed in a short-cycle hot press as already described in Example 1 to form a laminate with cured synthetic resin.
  • under the effect of increased pressure of at least 25 kg/cm ² and increased temperature of 200 °C
  • and a pressing time of 6 to 30 s
  • optionally with the formation of a surface structure above the decoration; if necessary, adjusted to each other, as so-called "embossed in register."

The impact resistance (large ball) determined on the coated waterproof chipboard in this example was 1400 mm. A test on a comparison product with a standard chipboard P2 only showed an impact resistance of 900 mm. The product with the waterproof chipboard therefore achieves usage class 33, whereas the comparison product with the standard chipboard P2 only achieves usage class 32.

If further processing of the coated waterproof chipboard is desired, e.g. to produce a panel with a profiled edge, this can be done in the same way as described in embodiment 4. The coated waterproof chipboard or a panel made from the coated chipboard can also be used in the same way. The properties of the carrier board coated according to embodiment 5 are comparable to those of the coated chipboard according to embodiment 1.

Implementation example 6 Carrier plate floor pressed with paper structure (elastic structure)

On the top 1a of a waterproof chipboard 1 (format: 2800 × 2070 × 10 mm) a decorative paper 2 and an overlay 2 are placed on top; an optionally used counter-sheet 4 is placed under the underside 1b of the chipboard 1 and this stack of pressed material consisting of three or four layers is pressed in a short-cycle press. Overlay 3, decorative paper 2 and the optionally used counter-sheet 4 are each used as synthetic resin-impregnated papers. Polyurethane dispersions were used as synthetic resin, here either PUR CHEM WB-420 or as a softer-to-the-touch variant PUR CHEM LC-380, each with the crosslinker PUR-CHEM AD-200R and, if necessary, a release agent such as WB-475; all of the aforementioned products are from the manufacturer PurChem Systems Inc.. The result is a coated, waterproof chipboard 1 that has a higher impact resistance than an identical structure with a standard chipboard P2.

A test of the impact resistance according to DIN EN 14354:2017-11, Appendix C, explains that a test object that has a resistance to impact stress (elasticity) of more than 1400mm thus reaches EC3 level. DIN EN 14323-07/2017, Section 5.13 with the large ball resulted in a value of 1500 mm for the waterproof chipboard 1 according to the invention. A test of a standard chipboard P2 with the same coating resulted in a value of 1200 mm.

• einem Dekorrohpapier mit einem Gewicht von 50 bis 90 g/m², mit
• eine vor oder nach dem Bedrucken durchgeführte Imprägnierung mit Kunstharz auf der Basis der vorstehend beschriebenen Polyurethandispersion (Feststoffgehalt: ca. 50 Gew%). Anschließend wird das Kunstharz getrocknet, aber noch nicht ausgehärtet, bis es mit einem Gewicht von 60 g/m² bis 110 g/m² vorliegt.

For the embodiment 6, a decorative paper is used as a synthetic resin-impregnated paper with a total weight of 110 to 200 g/m ² , based on

• a decorative base paper with a weight of 50 to 90 g/m ² , with
• impregnation with synthetic resin based on the polyurethane dispersion described above (solids content: approx. 50% by weight) before or after printing. The synthetic resin is then dried, but not yet cured, until it has a weight of 60 g/m ² to 110 g/m ² .

• einem Rohpapier mit einem Gewicht von 18 g/m² bis 50 g/m²
• einer Imprägnierung mit Kunstharz auf Basis der vorstehend beschriebenen PU-Dispersion (Feststoffgehalt: ca. 55 Gew%) aufgebracht wird, und dass nach der Trocknung, aber vor dem Aushärten mit einem Gewicht von 85 g/m² bis 320 g/m² vorliegt, sowie optional einem Korundgehalt von ca. 30 g/m², welcher durch Zugabe zur Dispersion oder durch Aufstreuen während oder nach dem Imprägnieren des Rohpapiers eingebracht wurde. Alternativ kann Korund bereits im Rohpapier enthalten sein.

Furthermore, an overlay is used as a resin-impregnated paper with a total weight of 103 to 400 g/m ² , based on

• a base paper with a weight of 18 g/m ² to 50 g/m ²
• an impregnation with synthetic resin based on the PU dispersion described above (solids content: approx. 55 wt%) is applied, and that after drying but before curing it has a weight of 85 g/m ² to 320 g/m ² , and optionally a corundum content of approx. 30 g/m ² , which was introduced by adding it to the dispersion or by sprinkling it on during or after impregnation of the base paper. Alternatively, corundum can already be contained in the base paper.

• einem Rohpapier mit einem Gewicht von 70 g/m² bis 120 g/m²
• einer Imprägnierung mit Kunstharz auf Basis der vorstehend beschriebenen PU-Dispersion (Feststoff-gehalt: ca. 55 Gew%), welche flüssig aufgebracht wird und welche nach dem Trocknen, aber vor dem Aushärten mit einem Gewicht von 80 g/m² bis 120 g/m² vorliegt.

Finally, an optional backing is used as a resin-impregnated paper with a total weight of 80 g/m ² to 240 g/m ² , based on

• a base paper with a weight of 70 g/m ² to 120 g/m ²
• an impregnation with synthetic resin based on the PU dispersion described above (solids content: approx. 55% by weight), which is applied in liquid form and which, after drying but before curing, has a weight of 80 g/m ² to 120 g/m ² .

• unter Wirkung von erhöhtem Druck mind. 25 kg/cm² und erhöhter Temperatur von z. B. 200 °C
• und einer Presszeit von 6 Sekunden bis 30 Sekunden und
• optional unter Ausbildung einer Oberflächenstruktur, die ggf. auf das Dekor angepasst ist (sogenanntes "embossed in register") ein Laminat hergestellt wird.

The further production of the coating on the workpiece is carried out by producing a pressed material stack which, from top to bottom, has the overlay as synthetic resin-impregnated paper, the decorative paper as synthetic resin-impregnated paper, the waterproof chipboard and optionally the counter-sheet as synthetic resin-impregnated paper. The pressed material stack is pressed into a laminate in a short-cycle hot press, whereby the short-cycle press has an upper press plate which acts on the overlay, and whereby

• under the effect of increased pressure of at least 25 kg/cm ² and increased temperature of e.g. 200 °C
• and a pressing time of 6 seconds to 30 seconds and
• Optionally, a laminate is produced with the formation of a surface structure that may be adapted to the decor (so-called "embossed in register").

Optionally, one or more lacquer layers can be applied to the overlay into which a structure is embossed, as described for embodiment 1.

This version of the coated, waterproof chipboard also has very low edge swelling, and here too the board shrinks back to its original thickness after drying. After the coating has been applied, smaller panels, so-called raw fixed dimensions, are produced from the waterproof chipboard on a multi-blade saw, which can then be further processed into flooring elements with a glueless profile. Compared to a standard P2 chipboard, the laminate floor made with the waterproof chipboard shows a significantly better milling pattern.

Example 7: Waterproof chipboard with veneer surface:

The starting materials are explained below. As an alternative to the paper backing (Alternative I), a veneer backing (Alternative II) can also be used. The veneer for the backing can be of the same or different, particularly simpler, quality as the veneer for the top. Veneer for the top: Strength: 0.6mm Type: Oak Paper: Resin-impregnated kraft paper Paper weight: 25g/ ^m2 Resin application: 600% Resin: Melamine resin waterproof chipboard: Thickness 7.8 mm Countermove: I Paper: Resin-impregnated kraft paper Paper weight: 25g/ ^m2 Resin application: 600% Resin: Melamine resin II Veneer Strength 0.6mm Type: poplar

The above information is exemplary and may vary, e.g. depending on the veneer used, e.g. the veneer thickness, the veneer moisture content or the density of the veneer or the type of wood of the veneer.

Production of resin-impregnated paper

The paper is passed through a bath of liquid synthetic resin, in this case melamine resin. In the bath, the paper is impregnated or soaked with liquid synthetic resin. After impregnation or soaking, excess synthetic resin is removed by a scraper so that a layer of synthetic resin is only on the top side of the now synthetic resin-soaked paper. The top side of the synthetic resin-soaked paper consists of synthetic resin, in this case melamine resin. The amount of synthetic resin used can be varied. However, it is preferably such that the applied veneer penetrates at least 2/3 of the veneer thickness during subsequent pressing by the synthetic resin liquefied in the press. The veneer is also preferably compressed in the press. According to a particularly preferred embodiment, after the pressing process has been completed, the veneer is at least 2/3, advantageously completely, impregnated with synthetic resin. Swelling and shrinkage of the veneer is thus largely reduced.

The soaked paper is dried to a residual moisture content of, for example, 5% to 6%. The resin application of the 25 g/m ² paper was 600% based on the weight of the paper. Drying takes place, for example, in a channel dryer in which hot air nozzles blow onto the paper from the top and bottom, drying it, but the synthetic resin is not hardened. The dried, synthetic resin-soaked paper can now be stored until it is used.

The resin-impregnated paper for the backing can be produced in the same way as described above. The resin-impregnated paper for the backing is also dried to a VC value of 6%, for example. The veneer for the backing can be prepared and then processed in the same way as the veneer for the top.

Making the veneered panel

The backing, carrier board, resin-impregnated paper and veneer are layered to form a stack of pressed material, with the resin-impregnated paper facing the top of the waterproof chipboard with its top side, which has the resin, and the bottom side facing the veneer. The stack of pressed material is placed in a short-cycle press (KT press) and pressed there at a temperature of 180°C and a pressure of p = 30 N/mm ² for a pressing time of 60 seconds.

It can be pressed with a simple, smooth press plate. In this embodiment, however, structured press plates can alternatively be used to provide structure. For example, a press plate with a wood structure can be used. The wood structure of the press plate can then be seen in the veneer, which can differ from the wood structure of the veneer. No recognizable melamine resin layer had formed on the top of the veneer. The coated, waterproof chipboard was then optionally finished with a UV varnish with an application quantity of 50 g/m ² to 100 g/m ² or with a UV oil with an application quantity of 20 g/m ² to 40 g/m ² in the surface. The application quantities were based on the desired usage class. Corundum can optionally be incorporated into the UV varnish, especially if higher usage classes with improved abrasion resistance are to be achieved.

The veneer surface on the top is thus accentuated or designed in a way that was not previously possible. The back of the waterproof chipboard can be left as it is, especially if a veneer has been applied according to Alternative II, or alternatively, impact sound insulation can be subsequently laminated on.

The method according to the invention offers better design options and thus better performance characteristics of a veneered panel.

Example 8 Coating with hotmelt

Another alternative for coating the surface of the inventive Chipboard is the application of a hot melt, e.g. a polyurethane hot melt (PU hot melt), a polyester, polyamide, polyolefin or polyacetate hot melt, e.g. ethyl vinyl acetate hot melt. In general, thermoplastics, in particular post-crosslinking thermoplastics, can be used as hot melts. Hot melts can be applied in one or more layers, with multi-layer application being preferred. Hot melts can contain the same additives as those described above for the application of plastic. Hot melts can be used unpigmented or pigmented, with the proportion of pigments being up to 30% by weight. Hot melts can be transparent or opaque. A hot melt can be applied to the entire surface of the workpiece according to the invention or in sections. A hot melt is applied in an amount of 10 g/m ² to 300 g/m ² , preferably in an amount of 50 g/m ² to 200 g/m ² . A hot melt is fixed by cooling after the hot melt is applied at a temperature of 80 °C to 160 °C, usually 100 °C to 130 °C. A hot melt can be rolled on, doctored on or sprayed on. A layer of hot melt that has already been applied and preferably already cooled can be printed on, in particular with water-based or UV-drying printing ink. A hot melt coating is also often combined with a layer of varnish, usually with a final, outer layer of varnish that forms the outside of the coated plate-shaped workpiece. A hot melt is also frequently used to fix other coating materials, in particular in combination with laminated materials such as Continuous Pressure Laminate (CPL) or High Pressure Laminate (HPL). In this case, however, the hot melt is not to be regarded as a surface coating, but as an adhesive for other coating materials.

• Aufbringen eines weißpigmentierten Polyurethan-Hotmelts (PU-Hotmelt) auf die Trägerplatte
• (Auftragsmenge: ca. 60 g/m² bis 120 g/m²), der bei einer Temperatur von 120 °C flüssig mit Hilfe eines Walzenauftragswerks auf die Oberfläche bzw. Oberseite der Trägerplatte, die hier als Werkstück dient, aufgetragen wird und, falls nötig, Glättung des noch flüssigen Hotmelts in einem zweiten Auftragswerk. Der Anteil an Pigment in der PU-Formulierung liegt bei ca. 20 Gew.-%.
• Abkühlen der Oberfläche
• Aufdrucken einer weißen, flüssigen Farbschicht mit einem Digitaldrucker (Auftragsmenge: 10 g/m² bis 20 g/m², anschließend ggf. Trocknen der Farbschicht, z. B. durch Umlufttrockner.
• Bedrucken der Oberfläche mit Hilfe eines Digitaldruckers mit einem Dekor unter Verwendung von wasserbasierten- oder UV-Tinten, anschließend ggf. Trocknen der Tinte, z. B. durch Umlufttrockner.
• Aufbringen einer weiteren, nicht pigmentierten PU-Hotmelt-Schicht (Auftragsmenge: 50 g/m²) mit Hilfe eines Walzenauftragsaggregats.
• Einstreuen von Korundpartikeln in den Hotmelt (Korngröße: F180 bis F240 nach FEPA-Standard) mit Hilfe einer Streuapparatur (Auftragsmenge: zwischen 10 g/m² und 50 g/m², je nach gewünschter Abriebfestigkeit).
• Auftrag einer weiteren PU-Schicht (Auftragsmenge: ca. 30 g/m²) mit einem Walzenauftragsaggregat.
• Abkühlen der Oberfläche
• Lackieren der Oberfläche mit einem UV-Lack, der ca. 30 g/m² Nanopartikel aus Korund zur Verbesserung der Kratzfestigkeit enthält (Lack-Auftragsmenge: 10 g/m² bis 40 g/m²) mit anschließender UV-Härtung.

In concrete terms, such a coating can be implemented as follows:

• Applying a white-pigmented polyurethane hotmelt (PU hotmelt) to the carrier plate
• (Application quantity: approx. 60 g/m ² to 120 g/m ² ), which is applied in liquid form at a temperature of 120 °C using a roller applicator to the surface or top of the carrier plate, which serves as the workpiece here, and, if necessary, smoothing the still liquid hot melt in a second applicator. The proportion of pigment in the PU formulation is approx. 20% by weight.
• Cooling the surface
• Printing a white, liquid layer of paint with a digital printer (application quantity: 10 g/m ² to 20 g/m ² , then drying the layer of paint if necessary, e.g. using a circulating air dryer.
• Printing the surface with a decoration using a digital printer using water-based or UV inks, then drying the ink if necessary, e.g. using a circulating air dryer.
• Application of another, non-pigmented PU hot melt layer (application quantity: 50 g/m ² ) using a roller application unit.
• Scattering corundum particles into the hot melt (grain size: F180 to F240 according to FEPA standard) using a scattering device (application quantity: between 10 g/m ² and 50 g/m ² , depending on the desired abrasion resistance).
• Application of another PU layer (application quantity: approx. 30 g/m ² ) with a roller application unit.
• Cooling the surface
• Coating the surface with a UV varnish containing approx. 30 g/m ² of corundum nanoparticles to improve scratch resistance (varnish application quantity: 10 g/m ² to 40 g/m ² ) followed by UV curing.

This coated chipboard can also be divided into panels and provided with edge profiles as described in embodiment 1. The use of the chipboard coated according to embodiment 3 and, if applicable, the panels made from it is also as described in embodiment 1.

List of reference symbols

1

waterproof chipboard

1a

Top

1b

bottom

2

Decorative paper

3

Overlay

4

Countermove

5

profile

6

adhesive

7

Thin laminate

Claims (14)

Method for coating a waterproof chipboard, wherein the chipboard comprises wood chips and at least one adhesive with an adhesive content of at least 12 wt.% /dry wood, comprising the steps: - Providing the chipboard having a top and bottom and side surfaces, - Applying a coating, - Applying a decoration, - if necessary, structuring of the coating, in each case on at least one section of a top side, a bottom side or a side surface, and - if necessary, curing of the coating. Method according to claim 1, characterized in that the coating is selected from the group of thermosetting synthetic resins, for example melamine resin, polyurethane resin, varnishes, for example UV-curable varnishes or hot melt. Method according to claim 1 or 2, characterized in that the coating is applied as a liquid coating, as a particulate coating, in the form of paper and/or in the form of a film, a veneer, a laminate and/or a felt. Method according to one of the preceding claims, characterized in that the coating is single-layered or multi-layered. Method according to one of the preceding claims, characterized in that the coating is cured under the influence of pressure and/or temperature. Method according to one of claims 1 to 4, characterized in that the coating is cured by radiation, in particular electron-curing radiation or UV radiation. Method according to one of claims 1 to 4, characterized in that the coating is fixed to the waterproof chipboard by adhesive. Method according to one of the preceding claims, characterized in that the structuring is produced by mechanical or chemical means. Method according to one of the preceding claims, characterized in that the coating is provided with additives, in particular corundum or glass beads. Chipboard, produced from a material comprising lignocellulosic chips and more than 12 wt.% adhesive, wherein the plate-shaped workpiece has an upper side, a lower side and side surfaces, characterized in that the upper side, lower side or at least one side surface are provided at least in sections with a coating which has a decoration and optionally a structure. Chipboard according to claim 9, characterized in that a primer is applied between the workpiece and the coating or onto a coating. Chipboard according to claim 9 or 10, characterized in that an adhesive is applied between the workpiece and the coating. Chipboard according to one of claims 9 to 11, characterized in that at least two opposite side surfaces have a profile exhibit. Use of the chipboard with a coating according to claims 10 to 13 as floor covering, wall covering, ceiling covering.

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