EA044952B1 - MULTILAYER FLOOR PANEL BASED ON PVC PLASTISOL - Google Patents

Description

Field of technology to which the invention relates

The present invention relates to floor panels having a multi-layer top layer containing polyvinyl chloride. More specifically, the invention relates to floor panels in which the top layer is attached directly to the base (substrate). Furthermore, the invention relates to a method for producing such floor panels and to a system for carrying out such a process.

State of the art

Floor panels are known in the art having a base and a multi-layer top layer containing polyvinyl chloride. These floor panels are often manufactured as rectangular planks or square tiles containing a mechanical locking system to assemble the panels together.

The base can be made of thermoplastic board, which can be foamed. The base may also contain wood or composite material. Multi-layer top layers known in the art comprise a decorative layer and a wear-resistant layer. Decor gives the floor panel an appearance, such as an image of a natural material such as wood or natural stone. The decor can be applied using printing inks using rotary intaglio printing, metallography or digital printing. The wear-resistant layer is transparent and is applied over the decor to protect it from abrasion.

When making these floor panels, the top layer can be applied as a multi-layer film or films stacked on top of each other. One or more films are laminated onto a substrate by calendering or pressing at an elevated temperature. The disadvantage of these pressure-based methods is that the combination of heat and pressure can be destructive, especially for foam substrates, causing the foam cells to collapse. Another disadvantage of these laminated films is their tendency to peel off from the substrate. Alternatively, you can use glue to adhere the top layer to the base. However, problems can arise because some adhesives lose some of their strength due to plasticizer flowing from the top PVC layer into the adhesive.

In addition, the flooring industry is constantly making efforts to create flooring products with a unique and highly realistic natural appearance, such as the appearance of a hardwood surface. Wood can have different surface textures depending on the wood and how it is prepared, e.g. whether they are cut so that the grain of the wood is visible, or so that the grain is substantially parallel to the cut surface of the wood. These surface structures can be improved by staining the wood. Light is reflected from wooden surfaces in the form of shine or scattering depending on the structure of the surface, that is, depending on the micro- or sub-microstructure. Commonly used finishing methods such as sanding affect microstructure and light scattering.

The microstructure is not visible from a normal distance, but can be seen with a magnifying glass. Microstructure influences surface glossiness, but the resulting glossiness is always a combination of microstructure and nanoscale structure. The microstructures may be inclined relative to the wood surface, which can influence the direction of light scattering. Many structured surfaces have a combination of nano-, micro- and macro-scale features. Macro-scale features such as grain, slope, crack, build-up, hole, etc. are visible to the naked eye. Macroscale elements do not affect the glossiness of the surface, but can influence its direction. Elements such as wood growth, wood grains, wood fibers are all macroelements.

Therefore, in addition to decor, the surface of the floor covering often contains a relief pattern, for example, imitating the texture of wood. The relief design is imprinted at elevated temperature and high pressure using an embossing die. This mechanical embossing process causes partial compression of the laminated films. The laminated film softens when heated, but at the same time has sufficient elasticity to subsequently partially recover. This can lead to partial disappearance of the relief pattern after the mold is removed. Particularly fine structures that affect shine and natural appearance are difficult to maintain.

Another disadvantage of sandwich floor panels is their tendency to curl. Curl is a phenomenon often observed in multilayer materials that have a heterogeneous composition and/or contain areas of internal stress that arise during processing and application. In particular, for floor panels consisting of multiple layers of different compositions, changes in temperature are believed to impart different degrees of contraction and/or expansion of the individual layers, resulting in either positive or negative curl. Because of this curling, installed floor panels tend to become non-flat and can separate from each other, leading to visual problems such as gaps between panels and damage. One or more very low thermal expansion reinforcing layers, such as fiberglass layers, or other additional layers may be included in the floor panel to resist or counterbalance the thermal expansion of the thermoplastic material. This often results in complex multilayer structures in which each layer has different thermal properties. However, when these additional layers are not precisely positioned to balance thermal properties, curl can still occur, especially when latent stress is present in the material.

Summary of the Invention

The purpose of embodiments of the present invention is to overcome at least one of the disadvantages of the prior art. An object of embodiments of the present invention is to provide a floor panel with reduced curl. In particular, the goal is to create a floor panel with a simple product configuration that has good dimensional stability.

Moreover, it is an object of the embodiments of the present invention to provide a floor panel with good aesthetics, especially a natural appearance.

Embodiments of the present invention provide floor panels having a multi-layer top layer comprising polyvinyl chloride. In particular, embodiments of the present invention relate to floor panels in which the top layer is directly attached to the base. Furthermore, the invention relates to a method for producing floor panels and to a system for carrying out such a process.

Floor panels in accordance with some embodiments of the present invention are defined in claims 1 to 22.

In a first aspect, the present invention relates to a floor panel comprising a base and a laminated top layer directly attached to the base, wherein the laminated top layer comprises a decorative layer comprising a fused PVC plastisol, a printed pattern applied in the form of single or stacked dots of material digitally printed over a decorative layer, a wear layer containing a fused PVC plastisol applied over the printed design, and optionally a varnish layer applied directly over the wear layer. The varnish layer can be a conformal layer, i.e. The varnish layer has the same thickness at all points of the wear layer. The advantage of this is that any relief pattern in the wear layer or decorative layer will be transferred through the varnish layer. The varnish layer may be a continuous or discontinuous transparent layer that matches the mechanically and/or chemically embossed relief patterns to which it is applied. Since the varnish layer is transparent, the appearance of the floor panel can be determined by the varnish layer, wear-resistant layer and digital printing on the decorative layer. In addition, the appearance of the gloss or glosses from the wear layer may be combined with the gloss or glosses from the varnish layer.

Methods for manufacturing a floor panel in accordance with some embodiments of the present invention are defined in claims 23-35.

According to a second aspect, the present invention relates to a method for manufacturing a floor panel, comprising the additional steps of providing a base, applying a first coating comprising PVC plastisol directly to the base to form a decorative layer, gelling the decorative layer, applying a printed pattern of single or stacked printed dots material onto the decorative layer by digital printing, applying a second coating comprising PVC plastisol to the printed decorative layer to form a wear-resistant layer, gelling the wear-resistant layer and then fusing the decorative layer and the wear-resistant layer and, optionally, applying a varnish layer directly over the fused wear-resistant layer.

The method may include the step of mechanically embossing the wear layer during gelation. The embossing mold can be in contact with the wear layer during gelation without applying additional pressure. The embossing plate may be a removable sheet and is preferably a resin-coated paper. The varnish layer can be a conformal layer, i.e. The varnish layer has the same thickness at all points of the wear layer. The advantage of this is that any relief pattern in the wear layer or decorative layer will be transferred through the varnish layer. Since the varnish layer is transparent, the appearance of the floor panel can be determined by the varnish layer, wear-resistant layer and digital printing on the decorative layer. In addition, the appearance of the gloss or glosses from the wear layer may be combined with the gloss or glosses from the varnish layer.

The varnish layer can be applied as a continuous or discontinuous transparent layer that matches the mechanically and/or chemically embossed relief patterns to which it is applied.

Brief description of drawings

In fig. 1 is a schematic representation of a floor panel according to the first aspect of the invention, showing a base (1) and a multi-layer top layer (2) comprising a decorative layer (3), a printed pattern (4), a wear layer (5) and, optionally, a varnish layer (6). ) directly on top of the wear layer.

In fig. 2 is a schematic representation of a method according to the second aspect of the invention for producing a floor panel, comprising the subsequent steps of (S1) providing a base, (S2) applying a first coating containing PVC plastisol directly onto the base to form a decorative layer, (S3) gelling a decorative layer, (S4) applying a printed pattern of single or stacked dots of printed material onto the decorative layer using digital printing, (S5) applying a second coating containing PVC plastisol onto the printed decorative layer to obtain a wear-resistant layer, (S6) gelling the wear-resistant layer and then fusing the decorative layer and the wear-resistant layer, (S7) applying a varnish layer directly on top of the fused wear-resistant layer. The varnish layer may be a conformal layer. The varnish layer may be a continuous or discontinuous transparent layer that matches the mechanically and/or chemically embossed relief patterns to which it is applied.

In fig. 3 shows a cross section of an article according to embodiments of the present invention.

In fig. 4 illustrates the various levels of surface structure used in some embodiments of the present invention. These different levels may be present in the embossed wear layer.

In fig. 5A-E illustrate various natural surfaces, which may include any macro-, micro-, nano-scale features, and any combination thereof, that can be produced by the methods of the present invention.

Definitions

Unless otherwise specified, all terms used in describing the invention, including technical and scientific terms, have the meaning commonly understood by one skilled in the art to which the invention relates. For further guidance, definitions of terms are included to better understand the principle of the present invention.

The term synthetic material as used in the context of the present invention may be a single polymer or a mixture of two or more polymers. The synthetic material may be, for example, a thermoplastic polymer, a thermoset polymer, a resona (elastomer), or any combination thereof. In addition, the synthetic material may be composed, for example, of any type of polymer, such as a homopolymer, copolymer, random polymer, alternating polymer, graft polymer, block polymer, star polymer, comb polymer, cross-linked polymer, and/or vulcanized polymer. The synthetic material may consist of, for example, thermoplastic elastomer (TPE), interpenetrating polymer network (IPN); simultaneously interpenetrating polymer network (IPN); or interpenetrating elastomeric network (IEM). The synthetic material may also include mixtures of synthetic polymers and natural polymers. The synthetic material may be a thermoplastic polymer, which includes, but is not limited to, vinyl-containing thermoplastics such as polyvinyl chloride, polyvinyl acetate, polyvinyl alcohol and other vinyl and vinylidene resins and copolymers thereof; polyethylenes such as low-density polyethylenes and high-density polyethylenes and copolymers thereof; polystyrenes and their copolymers, such as ABS, SAN and polypropylene and their copolymers; saturated and unsaturated polyesters; acrylics; polyamides, such as types containing nylon; engineering plastics such as polycarbonate, polyimide, polysulfone, polyphenylene oxide and sulfide resins, etc. Synthetic material can be virgin, recycled, or a mixture of both. Additionally, the synthetic material may be incorporated with foaming agent(s) or a mechanically injected gas or liquid, such as supercritical carbon dioxide, to produce a foaming or foaming structure.

As used herein, the term plasticizer should be understood as a compound used to increase the flow or ductility of a material, typically a polymer. The plasticizer for polyvinyl chloride may be a phthalic diester such as diisononyl phthalate (DINP). Other examples of plasticizers include, but are not limited to, ditridecyl phthalate, diisodecyl phthalate, dipropyl heptyl phthalate, diisooctyl terephthalate (DOTP), benzoates, adipates, any non-o-phthalate plasticizers, natural materials based plasticizers, and the like.

As used herein, the term PVC plastisol refers to a suspension of PVC particles in a liquid plasticizer. PVC plastisol flows as a liquid and can be poured. The composition, preparation and use of plastisols are described in detail, for example, in Krekeler/Wick, Kunststoff-Handbuch [Plastics Handbook] (1963), Volume 11, Part 1, pp. 396. Polyvinyl chloride used to form PVC plastisols can be a powder mixture. The polyvinyl chloride may be a microsuspension polymerization resin, a suspension polymerization resin, or an emulsion polymer resin having a preferred molecular weight reflected by its K value. If the temperature is high enough and time is sufficient, the PVC plastisol is converted from a liquid to a plasticized solid PVC material. Two successive stages of transformation can be distinguished. The first stage is the gelation of PVC plastisol. Thickening or gelling of PVC plastisol is a process in which the absorption of plasticizer(s) by polymer particles results in the formation of a so-called gelled plastisol, which is a dry and relatively weak gel. This condition can be considered to exist until further heating leads to fusion of the plastisol. At the second stage of transformation occurs

- 3 044952 complete fusion of PVC polymer particles to form a physically homogeneous plasticized solid PVC material with the most developed mechanical and other properties. The term fused PVC plastisol here refers to PVC plastisol in this final solid state.

The K value of a polymer is a measure of the length of the polymer chain and is described in detail in e.g. K.

Fickencher in Cellulosechemie, 13, 58 (1932).

As used herein, the term reinforcing layer refers to a woven or non-woven layer, such as fiberglass fabric or fiberglass fleece, or a textile layer.

As used herein, the term interlayer adhesive refers to a substance applied to one or both surfaces of two separate layers that binds them together and prevents them from separating. The interlayer adhesive material, for example, may comprise a one-component or multi-component adhesive, such as a two-component polyurethane liquid adhesive, such as polyurethane or epoxy resin; this may be a film such as double-sided tape or pressure-sensitive adhesive (PSA); or another layer or film containing a material that is compatible (ie, bonds) with both the first layer and the second layer. Examples include polyolefin copolymers such as ethylene/vinyl acetate, ethylene/acrylic acid, ethylene/n-butyl acrylate, ethylene ionomers, ethylene/methyl acrylate, and ethylene or propylene graft anhydrides. Other suitable adhesives include urethanes, copolyesters and copolyamides, styrene block copolymers such as styrene/butadiene and styrene/isoprene polymers, acrylic polymers, and the like. Adhesives may be thermoplastic or curable thermoset polymers and may include tacky, pressure-sensitive adhesives. In the context of the present invention, PVC-based adhesives are excluded from the definition of interlayer adhesive material. The term PVC adhesive should be understood as PVC being the main component of the adhesive which acts as a binder. Other suitable adhesives include foam craft adhesives such as 3M Styrofoam Spray Adhesive, dispersion adhesives, e.g. ACRONAL™ acrylate dispersions available from BASF, one-component polyurethane adhesives such as INSTASTIK™ available from The Dow Chemical Company, hot melt adhesives, moisture-curing adhesives such as those described in US 7217459B2, which is incorporated herein by reference, one-part or preferably two-component adhesives based on polyurethane resins or epoxy resins.

As used herein, the term blowing agent refers to a substance capable of forming a foamed polymer layer. Foaming agents are well known in the art, see, for example, Ullmann's Polymers and Plastics, 4 Volume Set: Products and Processes, p. 1578, Wiley-VCH Verlag, Weinheim, 2016. Blowing agents that release gas after being incorporated into a polymer are called in situ blowing agents and function by chemically decomposing the blowing agent under conditions called the foaming stage. The advantage of in-situ foaming agents is that they are selectively activated, resulting in the formation of foam. Chemical foaming agents are typically solids that decompose at elevated temperatures to produce gas, thereby causing expansion of the foam layer into the foam layer. Inorganic blowing agents such as ammonium bicarbonate or organic blowing agents such as p-toluenesulfohydrazide, 4,4'-oxybis(benzenesulfohydrazide), N,N'dinitrosopentamethylenetetramine or azodicarbonamide may be used. Organic foaming agents have a number of advantages over inorganic foaming agents in that they allow easier dispersion in the polymer composition, provide higher gas yields, decompose over a narrower temperature range, and are fairly stable during storage. Also, their decomposition temperature can be reduced below the operating temperature due to activation through the use of active kickers. By deactivating the kicker with inhibitory agents or increasing the thermal stability of the foaming agent, the decomposition temperature of the foaming agent-kicker mixture increases to a value above the operating temperature. Preferably, the foaming compositions used herein contain a chemical foaming agent containing nitrogen. The blowing agents that are most widely used are those N-N bonded compounds that decompose at elevated temperatures to form an inert gas with a high nitrogen content, also called nitrogen-containing blowing agents. Nitrogen has low permeability in polymers, which is highly desirable for making, for example, closed-cell foam layers. A particularly suitable nitrogen-containing blowing agent for polymers is azodicarbonamide. Thermal decomposition of azodicarbonamide results in the release of nitrogen, carbon monoxide, carbon dioxide and ammonia gases, which are retained in the polymer in the form of bubbles, forming a foam product. Although azodicarbonamide can be used in its pure form, it is preferable to modify it to affect the temperature range of decomposition. In general, foam agent decomposition depends on chemical activation, particle size and temperature. Accordingly, it is common practice to add kickers to compositions to lower the decomposition temperature and/or narrow the decomposition temperature range. Although azodicarbonamide typically begins to decompose at 200°C, the addition of a kicker such as zinc oxide can lower the decomposition temperature to a range of 160 to 195°C. Useful foaming agents include, but are not limited to, citric acid, oxalic acid, toluenesulfonic acid, phosphoric acid, potassium carbonate, borax, triethanolamine, zinc chloride, zinc acetate, zinc oxide, zinc stearate, barium stearate, calcium stearate, urea and polyethylene glycol. Preferably, at least one foaming kicker contains zinc oxide or zinc oxide and urea. The nitrogen-containing blowing agent and at least one blowing agent kicker are preferably mixed together before being added to the polymeric material. To obtain chemically embossed foam, it is preferable to use azodicarbonamide with a high foam activator. Azodicarbonamide in combination with a kicker is a preferred blowing agent when forming a foamable material, particularly in materials containing polyvinyl chloride (PVC), especially plasticized PVC, since it can be easily incorporated into the polymeric material. The preferred kicker for this invention is zinc oxide and/or urea. The amount of kicker is typically from about 10 to 70% by weight of azodicarbonamide, preferably from 20 to 50%, and most preferably from about 35 to 45%. Since particle size also affects the speed and gas release, as well as the size of the foam cells thus formed, the nitrogen-containing foaming agent and at least one foaming agent and kicker preferably have an average particle size of less than 5 μm, more preferably less than 4 μm when measured by laser device for measuring particle size. The foaming agent is preferably uniformly dispersed in the foaming layer.

The term digital printing process here refers to the method of printing digital images or designs directly on top of a substrate. Digital printing results in single or stacked dots of printed material being deposited onto a surface with unprinted areas in between. Examples of digital printing methods include inkjet printing and laser printing. The preferred digital printing technology in this case is inkjet printing. Inkjet printing is a digital printing technology known in the art that recreates a digital image or pattern by directing droplets of printed material onto a substrate. Generally, there are two main technologies used in modern inkjet printing processes: continuous flow (CD) and droplet on demand (DOD). Typically, DOD print-on-demand heads using piezoelectric crystals, for example, are used to eject droplets from a nozzle opening onto a substrate. Digital printing techniques improve the applicability of printing processes and provide a greater degree of flexibility in the print patterns that can be applied to the substrate. Another advantage of using digital printing methods over analog printing is that the printing pattern can be tailored according to the client's preferences.

The term chemical embossing is known in the art and is based on the principle that the degree of foaming of the foam layer is locally influenced by a so-called defoamer. The defoamer can be applied to the foam layer using printing technology, preferably digital printing. The effectiveness of inhibition depends on the permeability, solubility and diffusion rate, as well as the distance of the defoamer from the foam-forming layer. A wide range of compounds can be used as inhibitors of chemical embossing of foam layers on floor covering surfaces. The choice of inhibitor depends on the specific foaming agent used in the foaming layer. Triazole compounds such as benzotriazole (BTA), tolyltriazole (TTA) and derivatives and/or combinations thereof can be conveniently used as an antifoam agent for chemical embossing of a foam material containing azodicarbonamide as a blowing agent and ZnO as a kicker. The preferred antifoaming agent is 1Hbenzotriazole-1-methanamine, K,K-bis(2-ethylhexyl)ar-methyl (CAS 94270-86-7). The defoamer is preferably present in the liquid carrier, allowing greater control over the amount of inhibitor applied. Preferably, the antifoam is present in the carrier at a concentration of 1 to 20% by weight based on the total weight of the digital printing material, more preferably in an amount of 7 to 15% by weight, and even more preferably from 9 to 12% by weight. The defoamer-containing material may contain a bonding material that provides at least partial cure after the dots are printed to prevent the dots from bleeding and allow additional (stacked) dots to be applied immediately thereafter, while reducing possible defects . More preferably, the binder material is radiation-curable, preferably UV-curable. To obtain high flexibility and good adhesion, the binder material preferably contains acrylate. Preferably the acrylate includes isobornyl acrylate (CAS 5888-33-5), dipropylene glycol diacrylate (CAS 57472-68-1) or combinations thereof. More preferably, the digital printing material contains from 10 to 30 wt.% isobornyl acrylate and from 5 to 30 wt.% dipropylene glycol diacrylate. The defoamer containing material may further contain a UV initiator, preferably in an amount of 1 to 10% by weight depending on the total weight of the digitally printed material. A highly preferred UV initiator is trimethylbenzoyldiphenylphosphine oxide (TPO), known under CAS number 75980-60-8. In any case, regardless of whether the material containing the defoamer is radiation-cured or physically dried, the defoamer has been found to penetrate into the foam layer after printing, as evidenced by

- 5 044952 there are depressions formed by the expansion of the foam in places where the digital image dots of the printed foam-inhibiting material were superimposed. In addition, a particular advantage of the present invention is that multiple dots of inhibitor material can be printed in the same location, resulting in, for example, a higher local amount of inhibitor in the foam layer and therefore a greater reduction in foam formation . In this way, in very specific places, higher elevation differences in the relief can be achieved, allowing, for example, to create a more natural appearance of decoration, such as a pronounced wooden or porous stone image. Additionally, the amount of defoamer required to achieve maximum drop is less than with conventional (rotary gravure) printing, reducing the overall amount of defoamer required. At the same time, the resolution of chemical embossing areas can be increased in proportion to the resolution of digital printing technology.

The term embossing as used herein is known in the art and is based on the principle that portions of the surface of a material are shaped into structures both visible and invisible to the human eye. Embossing is perceived as structural elements (edges, features) and as light scattering. Three levels of structure can be defined: a macrostructure that is 50 microns in size or larger and can be seen by the human eye, a microstructure that is less than 50 microns in size but larger than 1 micron and is difficult to see or invisible, and a light scattering structure that is less than 1 micron in size, which usually not visible except for shine.

These three levels of structure are shown schematically in FIG. 4.

The mechanical embossing used here is known in the art and is based on the principle that parts of the surface of the material are shaped using a so-called embossing mold.

As used herein, the term transparent is intended to denote a material that transmits visible light to a significant extent.

Detailed Description of the Invention

The present invention relates to floor panels, such as planks or tiles, that can be selectively assembled together, for example, using mechanical connections. The floor panel may have any suitable length and/or width and may have any shape, such as a rounded shape and a polygonal shape (triangle, rectangle, square, pentagon, hexagon, heptagon or octagon). Preferably, the floor panel is rectangular in shape with short sides having a width of 10 to 120 cm and long sides having a length of 50 to 300 cm. Alternatively, the floor panel is in the shape of a square (tile) with a side length of 20 to 150 cm Floor panels can have a surface with different zones that can reflect or diffuse light, and can have any of macro-, micro-, and nanoscale surface structures, or any combination thereof. One or more of these zones can be addressed by digitally printing a base (1) with a decorative layer and a multi-layer top layer (2) consisting of a decorative layer (3), a printed pattern (4), a wear layer (5) and, optionally, a varnish layer (6) directly on top of the wear-resistant layer. The varnish layer may be a continuous or discontinuous transparent layer that matches the mechanically and/or chemically embossed relief patterns to which it is applied.

As shown in FIG. 1 and 3, according to the first aspect, the present invention provides a floor panel comprising a base (1);

a multi-layer top layer (2) directly attached to the base (1), wherein the multi-layer top layer (2) contains a decorative layer (3) consisting of fused PVC plastisol, a printed pattern (4) applied in the form of single or stacked a friend of dots of digitally printed material on top of a decorative layer (3), a wear-resistant layer (5) consisting of a fused PVC plastisol placed on top of the printed design (4), and optionally a layer of varnish applied directly on top of the wear-resistant layer.

Preferably, the base 1 is single-layer. It is preferable that the base is made of PVC.

In fig. 3 shows how the varnish layer can be a conformal layer, i.e. The varnish layer has the same thickness at all points of the wear layer. The advantage of this is that any relief pattern in the wear layer and/or decorative layer will be transferred through the varnish layer. This allows the top surface of the floor panel to have nanoscale, microscale and macroscale features. In addition, the varnish layer may have different levels of gloss, which may be located in any part of the macroscale or microscale elements of the wear layer. Since the varnish layer is transparent, the appearance of the floor panel can be determined by the varnish layer, wear-resistant layer and digital printing on the decorative layer. In addition, the appearance of the gloss or glosses from the wear layer may be combined with the gloss or glosses from the varnish layer.

- 6 044952

In fig. 4 illustrates the various levels of surface structure used in some embodiments of the present invention. These different levels may be present in the embossed wear layer.

In fig. 5 shows different levels of surface structure of natural products such as wood (FIGS. 5A-B) and stone (FIGS. 5D-E).

In fig. 4 and 5 show macroscale (22 in Fig. 4 and 52 in Fig. 5B, and 51 in Fig. 5E), microscale (24 in Fig. 4 and 54 in Fig. 5B and 53 in Fig. 5D) and nanoscale elements ( 26 in Fig. 4 and 56 in Fig. 5A, and 55 in Fig. 5D). The examples shown in these figures of macro-scale elements present in some natural products are narrow and deep. An example is the macroscale groove 22 in FIG. 4, similar to the natural wood groove 52 in FIG. 5B, which may be present on some cut wood samples, and the slate groove 51 in FIG. 5D. These shapes can be created using the molding technology of the present invention since the embossing can be formed in the wear layer (5) during gelation of the layer. Therefore, little pressure is required so that the tall thin elements on the mold do not break. Moreover, as shown in FIG. 4, nanoscale (26) or microscale (24) elements can be placed anywhere on the macroscale elements (22).

Nanoscale features can have gloss, and therefore different glosses can be placed at any position of macroscale features.

The inventors have discovered that by applying a flexible multi-layer top layer to a rigid substrate, curl can be minimized and a curl-free floor panel can be achieved.

This is especially true when the ratio between the elastic moduli of the base and the multi-layer top layer is at least 20, preferably in the range of 20 to 10,000, more preferably in the range of 20 to 1000 and even more preferably in the range of 20 to 500, measured at temperature 23 ± 2°C and relative humidity 50 ± 10% in accordance with ISO 527. ISO 527 Plastics - Determination of tensile properties consists of several parts, of which the following are important for the purposes of the present invention.

Part 1, ISO 527-1:2012 General principles defines the general principles for determining the tensile properties of plastics and plastic composites under specified conditions. Several different types of test pieces are specified to suit different types of materials, which are described in detail in subsequent parts of ISO 527.

Part 2, ISO 527-2:2012 Test conditions for molding and extrusion plastics, specifies test conditions for determining the tensile properties of molding and extrusion plastics based on the general principles of Part 1.

Part 3, ISO 527-3:2018 Test conditions for films and sheets, specifies conditions for determining the tensile properties of plastic films or sheets less than 1 mm thick, based on the general principles set out in ISO 527-1.

All test specimens were cut or punched to the size of Type 1B specimens. The testing speed of the tensile testing machine was maintained at 1 mm/min.

The corresponding ISO 527 parts are used depending on the type and/or thickness of the parts (base and laminated top layer) of the bridge panel.

The basis

The base may contain one or more layers. The base has a first upper surface and a first lower surface. In the preferred embodiment, and optionally in all embodiments, the base consists of a single layer. The base can be made of a synthetic material or a composite material such as stone plastic composites (KPC) and wood plastic composites (WPC), which can be foamed if necessary. Stone-plastic composites may contain calcium carbonate (limestone), polyvinyl chloride and plasticizers. Wood-plastic composites typically contain thermoplastic materials and wood-like or wood-based materials such as wood flour. The base may also be made of wood or a wood-based material such as fiberboard or particle board.

Preferably, the base comprises polyvinyl chloride. More preferably, the base contains polyvinyl chloride and consists of a single layer. The polyvinyl chloride used to form the base can be a powder formulation that is easy to process, has high extrusion speed, good surface properties, excellent dimensional stability and indentation resistance. Additionally, high and uniform resin particle porosity is preferred to optimize mixing and processing aspects, including rapid and uniform absorption of any stabilizer present, as well as other ingredients during mixing. The polyvinyl chloride may be a suspension polymer resin or a bulk polymer resin having a preferred molecular weight as reflected by its K value. In a preferred embodiment, the base comprises a polyvinyl chloride with a K value between 50 and 80, more preferably between 55 and 70. The polyvinyl chloride preferably has a narrow molecular weight distribution and narrow particle size distribution to ensure a good balance between processability and material properties. The polyvinyl chloride is preferably a suspension PVC. It has been observed that lower K values are preferred for foamed bases.

The base preferably contains at least one filler or source of filler. Filler is used to optimize mechanical properties and reduce the cost of the base material. The fill source may include virgin materials, but may also include post-industrial or recycled materials such as gypsum, glass, energy by-products, wood, plastic (eg PVC), recycled panels or parts thereof, and the like. or all of this. The filler may be a natural filler or a synthetic filler. The filler can be in the form of particles, short fibers, flakes and other discrete forms. Inorganic filler (such as mineral fillers) as well as organic (non-mineral) fillers can be used. Examples of inorganic filler include, but are not limited to, hydrated alumina, magnesium carbonate, calcium carbonate, calcium sulfate, silica, precipitated silica, fumed silica, fly ash, cement dust, glass, clay, chalk, limestone, marble, talc, mica, barium sulfate, silicates, aluminum trihydrate, kaolin, wollastonite, gypsum, solid or hollow glass microspheres, etc. Examples of non-mineral or organic filler include, but are not limited to, carbon black, wood flour, cellulose-derived materials, milled rice hulls, solid or hollow heat-resistant polymer microspheres or microbeads (eg, phenolic microspheres), and the like. Carbon black, for example, can be used in rubber-based core or other types of core panels.

Preferably, the filler is selected from the group consisting of calcium carbonate, magnesium carbonate, talc, chalk, wollastonite, mica and combinations thereof.

In another preferred embodiment, said base contains a filler which increases the modulus of elasticity of the base, said filler consisting predominantly of a mixture of talc and chalk. The mentioned high modulus of elasticity corresponds to the high rigidity and heat resistance of the resulting panel.

The filler may be present in the base in an amount from 10 to 85% by weight, depending on the total weight of said base. In some embodiments, the filler may be present in an amount of from 20 to 80 wt.% depending on the total weight of the specified base. In other embodiments, the filler may be present in an amount of from 40 to 80% by weight depending on the total weight of said base. In yet other embodiments, the filler may be present in an amount of from 30 to 60% by weight depending on the total weight of said base.

The base may contain one or more plasticizers. One or more plasticizers are present in the base in an amount of less than 15% by weight, depending on the total weight of said base. More preferably, said one or more plasticizers are present in an amount of less than 10% by weight, even more preferably less than 5% by weight depending on the total weight of the substrate, and even more preferably in an amount of less than more than 2% by weight. This is advantageous because the reduced amount of plasticizers provides a base with a high modulus of elasticity, high stiffness and high temperature resistance.

The base may also include pigments, flame retardants, antimicrobial additives, processing aids, stabilizers, impact modifiers, or other conventional organic or inorganic additives commonly used in polymers used in the field of surface coatings.

In a preferred embodiment, the base according to the present invention does not contain a reinforcing layer.

In a preferred embodiment, the base is a foam base, preferably a rigid foam base. Desirably, the foam base comprises a synthetic foam, which is a foam composition with a polymeric continuous matrix material and filler. Suitable polymer foams include extruded polymer foams, expanded polymer foams, liquid-dispensable free- or limited-rise polymer foams, and molded polymer foams. The foam may and desirably contains as a continuous phase a thermoplastic polymer matrix material or a thermoset polymer matrix material or mixtures thereof. Additionally, the ISO 527 standard is used to determine the tensile properties of a foam core, preferably a rigid foam core.

In a preferred embodiment, the base is a rigid foam base containing PVC.

The density of the base is usually selected depending on the specific application. Preferably, the density of the base is equal to or less than about 1600 kg/m ³ , more preferably less than about 1400 kg/m ³ , even more preferably less than about 1300 kg/m ³ . Preferably, the density is equal to or greater than about 400 kg/m ³ , more preferably greater than about 600 kg/m ³ , even more preferably greater than about 800 kg/m ³ and most preferably greater than about 1000

- 8 044952 kg/m ³ . In preferred embodiments, the density of the foam base is from 1050 to 1300 kg/m ³ , more preferably from 1100 to 1200 kg/m ³ .

In a preferred embodiment, according to the first aspect, the base has a thickness of from up to 25 mm. Preferably the base has a thickness of from 1.5 to 20 mm, more preferably from 1.5 to 7 mm and even more preferably from 2.4 to 5.8 mm.

In a preferred embodiment, according to the first aspect, the base is rigid. The term hard in the context of the present invention refers to the characteristics of a substrate with a modulus of elasticity greater than 2000 MPa measured at a temperature of 23 ± 2°C and a relative humidity of 50 ± 10%, according to ISO 527, and (if applicable) a glass transition temperature (Tg) of 70°C or higher, measured in accordance with ISO 6721-11:2019(E), method B, with a heating rate of 2 K/min and a test frequency of 1 Hz. Preferably, said base has an elastic modulus of 2000 to 4000 MPa or 4000 MPa or higher. It is possible to obtain elastic modulus from 2000 or 4000 MPa to 8000 MPa. For example, by using an optimized amount of filler, such as inorganic filler, i.e. talc and chalk, a base containing PVC with an elastic modulus of up to 8000 MPa can be reasonably obtained. Preferably, said base has (if applicable) a glass transition temperature (Tg) of 80°C or higher, and more preferably a glass transition temperature (Tg) of 85°C or higher. The transition temperature (Tg) is determined using the peak temperature in the corresponding loss factor (tan delta) DMA curves as a function of temperature.

Multi-layer top layer

According to a first aspect of the invention, the multi-layer top layer comprises a decorative layer consisting of fused PVC plastisol, a printed pattern applied in the form of single or stacked dots of digitally printed material over the decorative layer, a wear-resistant layer consisting of fused PVC plastisol applied over the printed pattern selectively, a layer of varnish applied directly over the wear-resistant layer.

The multilayer top layer has a second top surface and a second bottom surface. The multi-layer top layer can have a thickness from 0.15 to 1.7 mm. Preferably, the multilayer top layer has a thickness of 0.3 to 1.5 mm, more preferably 0.4 to 1.3 mm, and most preferably 0.5 to 1.2 mm.

In a preferred embodiment, according to the first aspect, the multilayer top layer is a flexible layer that does not contain a reinforcing layer. The term flexible layer in the context of the present invention refers to a multilayer top layer with a modulus of elasticity of 100 MPa or lower, measured in accordance with ISO 527. The glass transition temperature (Tg) may be 45°C or lower, measured in accordance with ISO 6721-11: 2019(E) method B, at a heating rate of 2 K/min and a testing frequency of 1 Hz. Preferably, said multilayer top layer has an elastic modulus in the range of 20 to 100 MPa. Preferably, said multilayer top layer has a glass transition temperature (Tg) of 40°C or lower, and more preferably a glass transition temperature (Tg) of 35°C or lower. The junction temperature (Tg) is determined using the peak temperature on the corresponding loss factor (tan delta) DMA curves as a function of temperature.

The inventors have found that the multilayer top layer in accordance with embodiments of the present invention exhibits good adhesion to the substrate without necessarily using a separate adhesive or adhesive material. The first top surface of the base is preferably in direct contact with the second bottom surface of the multi-layer top layer.

Thus, the floor panel preferably does not contain an interlayer adhesive material that binds the base and the multi-layer top layer together. This is especially important when the multi-layer top layer is attached directly to a PVC-containing backing.

The peel resistance of the base from the multi-layer top layer has been found to be at least 50 N/50 mm, more preferably at least 100 N/50 mm, and even more preferably at least 200 N/50 mm. Peel strength is determined according to the following peel test. The peel test is carried out on a tensile test apparatus including a peel test fixture similar to that described in EN1464:2010(E). The tensile testing apparatus shall maintain a specified constant crosshead speed, preferably 100 mm/min. The test sample is conditioned in a laboratory atmosphere at a temperature of 23°C and a relative humidity of 55% RH for 7 days. Three samples measuring 280 mm by 50 mm are taken from the test sample. The initial separation of the multi-layer top layer and base over a distance of more than 50 mm is initiated with a cutter and/or pliers. The unbonded end of the flexible laminated topsheet is folded perpendicular to the rigid substrate to be clamped into the test device clamp. The sample is placed horizontally in the peel test fixture with the unbonded end

- 9 044952 of the flexible multi-layer top layer is directed downward and clamped in the grip of the testing machine. The test sample is separated at a constant crosshead separation speed of 100 +/- 5 mm/min. The traverse stops after peeling off 200 mm of the glued length. From the autograph curves of the three samples, which display the dependence of the force on the movement of the traverse, the average peel resistance in newtons is determined for 50 mm of the test sample. The first 50 mm and last 50 mm of peeling are not taken into account when determining the average peel resistance.

Decorative layer

The decorative layer preferably contains a fused PVC plastisol. The decorative layer has a third upper surface and a third lower surface. The third bottom surface may be the same as the second bottom surface of the multi-layer top layer. Therefore, the third lower surface of the decorative layer may be in direct contact with the first upper surface of the base. Preferably, the decorative layer comprises polyvinyl chloride with a K value between 50 and 75, more preferably between 55 and 70. The decorative layer preferably contains emulsion PVC or microsuspension PVC with a K value between 50 and 75, and more preferably between 55 and 70.

The decorative layer may further include one or more additives known in the art, such as fillers, pigments, foaming agents and stabilizers.

The decorative layer may contain one or more fillers. The filler may be present in an amount from 15 to 60 wt.% depending on the total mass of the decorative layer. In some embodiments, the filler may be present in an amount of from 15 to 50% by weight, depending on the total weight of the decorative layer. In other embodiments, the filler may be present in an amount of from 15 to 45% by weight, depending on the total weight of the decorative layer. Suitable fillers for the decorative layer are the base fillers described here.

In a preferred embodiment, the filler is selected from the group consisting of calcium carbonate, magnesium carbonate, talc, chalk, wollastonite, mica, and combinations thereof. In another preferred embodiment, said decorative layer contains a filler, said filler consisting predominantly of a mixture of talc and chalk.

In a preferred embodiment, the decorative layer contains one or more plasticizers. One or more plasticizers may be present in an amount from 10 to 35% by weight, depending on the total weight of the decorative layer. More preferably, said one or more plasticizers are present in an amount of from 10 to 30% by weight, even more preferably from 10 to 25% by weight, depending on the total weight of the decorative layer.

The decorative layer may contain pigments or dyes distributed evenly or unevenly in the layer. Pigments or dyes can provide the base color of the decorative layer. Titanium dioxide can be used, for example, as a white pigment.

In a preferred embodiment, according to the first aspect, the decorative layer has a thickness of 0.10 to 0.70 mm, preferably 0.25 to 0.60 mm.

Printed drawing

The multi-layer top layer contains a printed design applied in the form of single or stacked dots of digitally printed material on top of the decorative layer. The printed pattern is preferably printed using inkjet printing. The printed design preferably comprises digitally printed ink dots forming a decorative image with a resolution ranging from 100 to 4800 dpi, preferably from 400 to 800 dpi. The printed design can be produced using so-called black, cyan, magenta and yellow inks. Ink typically includes a liquid carrier and one or more solids, such as dyes or pigments and polymers. UV-curable inkjet inks have proven particularly useful. The ink preferably contains one or more photoinitiators in a suitable amount and a suitable decomposition absorption spectrum.

Wear layer

A wear-resistant layer consisting of fused PVC plastisol is applied on top of the printed pattern. Preferably, the wear-resistant layer is applied to most of the surface of the printed decorative layer and more preferably to the entire surface of the printed decorative layer. The wear layer is at least translucent, preferably transparent, and is applied to protect the floor panel from wear. The thickness of this wear resistant layer is preferably from about 0.10 to about 1.00 mm, more preferably from about 0.10 to about 0.70 mm, and most preferably from 0.20 to 0.70 mm.

In a preferred embodiment, the wear layer comprises a polyvinyl chloride with a K value between 50 and 95, more preferably between 60 and 85. The polyvinyl chloride preferably comprises microsuspension grade PVC or emulsion grade PVC or a mixture of both.

The wear layer may include one or more additives known in the art, such as plasticizers, filler, pigments, wear particles, cross-linking agents and UV stabilizers. The wear layer may contain one or more plasticizers. One or more plasticizers may be present in an amount of from 10 to 35% by weight, depending on the total weight of the wear layer.

In one embodiment, the wear layer contains no filler.

Varnish

A finishing topcoat or varnish may optionally be applied directly to the top surface of the wear layer. The varnish increases the resistance of the floor panel to scratches. This varnish may be a thermoset layer or a thermoplastic layer. The varnish may be, for example, a water-based, solvent-based, radiation-curable, non-radiation-curable, UV-curable, or non-UV-curable system. For example, the varnish may be composed of acrylics, acrylates, urethanes, epoxy resins, other types of vinyl, other types of polymers, and mixtures thereof, provided that the composition cures to produce a rigid, thermosetting coating with sufficient cross-link density. The varnish may contain fillers and other additives, for example to improve scratch resistance.

The varnish layer can be a conformal layer, i.e. The varnish layer has the same thickness at all points of the wear layer. The advantage of this is that any relief pattern in the wear layer and/or decorative layer will be transferred through the varnish layer. The varnish layer can be applied as a continuous or discontinuous transparent layer that matches the mechanically and/or chemically embossed relief patterns to which it is applied.

In the most preferred embodiment, the floor panel according to the present invention comprises a base containing PVC, a multi-layer top layer directly attached to the base; wherein the multilayer top layer contains a decorative layer consisting of fused PVC plastisol, a printed pattern applied in the form of single or stacked dots of digitally printed material on top of the decorative layer, a wear-resistant layer consisting of fused PVC plastisol applied selectively over the printed pattern a layer of varnish applied directly over the wear layer.

The inventors have discovered that the multi-layer top layer in accordance with the invention exhibits exceptionally good adhesion to a PVC-containing substrate without the need for a separate adhesive or adhesive to bond the top layer to the substrate, and has excellent dimensional stability without the need to add one or more reinforcing layers either in the base or in the top layer. The varnish layer may be a continuous or discontinuous transparent layer that matches the mechanically and/or chemically embossed relief patterns to which it is applied. Since the varnish layer is transparent, the appearance of the floor panel can be determined by the varnish layer, wear-resistant layer and digital printing on the decorative layer. In addition, the appearance of the shine or shines from the wear layer may be combined with the shine or shines from the varnish layer.

The floor panel may consist of a base containing PVC;

a multi-layer top layer directly attached to the base; wherein the multilayer top layer contains a decorative layer consisting of fused PVC plastisol, a printed pattern applied in the form of single or stacked dots of digitally printed material on top of the decorative layer, a wear-resistant layer consisting of fused PVC plastisol applied on top of the printed pattern, and optionally, a varnish layer applied directly over the wear layer. The varnish layer can be a continuous or discontinuous, transparent layer that matches the mechanical and/or chemically embossed relief patterns to which it is applied.

Additional embodiments

In one embodiment, the decorative layer is a foamed decorative layer. A foamed decorative layer can be produced by incorporating one or more blowing agents into a plastisol PVC coating and allowing the decorative layer to expand at elevated temperatures. The foamed decorative layer may have a spongy or foam structure, which has a lower bulk density than the non-foamed decorative layer. The foamed decorative layer primarily ensures optimal shock-absorbing and acoustic characteristics of the floor panel.

The foamed decorative layer can have a chemically embossed relief pattern. The chemically embossed relief design contains indentations formed by single or stacked

- 11 044952 on each other with dots of digitally printed material containing an antifoam agent. By applying a defoamer it is possible to achieve large differences in the height of the relief in certain places, which allows, for example, to achieve a more natural look for decors containing pronounced images of wood or porous stone. In addition, the amount required to achieve maximum height difference is less than with conventional (rotary gravure) printing, reducing the overall amount of defoamer required. The resolution of the chemical embossing pattern is preferably in the range of 100 to 1200 dpi, more preferably 300 to 1000 dpi, even more preferably 360 to 600 dpi.

The digitally printed material containing the defoamer may selectively contain ink. The ink and defoamer can be applied together, so the ink pattern usually follows the relief pattern.

In a preferred embodiment, the digitally printed material containing the defoamer does not contain ink. Separate or parallel printing of inhibitor and ink effectively separates the relief design from the decorative ink design. The location and depth of the chemically embossed relief can be selected independently of the pattern applied by the printing ink. This gives the designer more design freedom, allowing the creation of color gradients and high-resolution structures of both relief and decoration, reducing or even avoiding repetition.

The wear-resistant layer may contain a mechanically embossed surface structure, which can be made in the form of a relief pattern. The mechanically embossed surface structure typically includes micro- and nanoscale elements. Microscale features have feature depths ranging from 1 to 50 µm. Nanoscale features have feature depths of less than 1 µm. The elements discussed here are predefined, that is, elements that are intentionally transferred to the wear layer through the embossing process, and not simply elements that are initially present on the surface due to natural surface topography, surface contamination, etc. Micro- and nanoscale elements influence tactile and aesthetic properties floor panels. Nanoscale features are invisible, but scatter visible light and are therefore perceived as glossy.

In a preferred embodiment, the floor panel comprises a mechanically embossed surface structure containing deflecting micro- and nanoscale features resulting in zones of varying topography and varying gloss levels. Gloss is characterized by the directional reflection of incident light, also called specular reflection. According to ISO2831, the gloss level can be determined by measuring with a reflectometer. The reflectometer emits a beam of light at a specified angle of incidence onto the surface to be tested and receives the beam of light reflected by the surface. The ratio of light intensity between emitted and received light rays characterizes the gloss level of a surface. The gloss level is divided into gradations from high gloss (incidence angle 20°, reflection from 60 to 70%) to glossy (60°, 55-65%), silky gloss (60°, 25-35%)), silky matte ( 85°, 40% to 50%), to matte (85°, 6% to 8%).

In a preferred embodiment, the floor panel according to the invention has at least two zones with different gloss levels. The floor panel may, for example, have a first zone with a high gloss finish, a second zone with a silky gloss finish and a third zone with a matte finish.

The magnitude and angular distribution of reflective scattering from a surface can be determined using bidirectional reflectance distribution function (BRDF) measurements (ASTM E 2387-05 Standard Practice for Measuring Goniometric Optical Scattering Zones).

In a preferred embodiment, the floor panel according to the invention has macro-, micro- and nano-scale elements.

In fig. 4 illustrates the various levels of surface structure used in some embodiments of the present invention. These different levels may be present in the embossed wear layer.

First level - nanoscale elements

All materials have a light-scattering structure. Light scattering can be represented as a combination of any of the following types of gloss and diffused light: specular gloss, wide gloss, diffuse scatter, and any or all of these can be combined with a given color pattern in a printed pattern on the decorative layer. The way light is reflected as glare or scattering depends on the structure of the surface. There may be many zones on the surface having a light-scattering structure, not necessarily the same light-scattering structure, but selectively different.

Second level - microscale elements

Most plate surfaces and materials have a combination of light scattering and microstructure. Most surface roughness values in the standards are in the microstructure region. For example, the most commonly used finishing processes, such as sanding, will affect microstructure and light scattering. The microstructure is not visible from a normal distance, but can be seen up close or with a magnifying glass. Microstructure will influence surface gloss, but the resulting gloss is always a combination of microstructure and nanostructure. The microstructure may have angular or inclined elements that can influence

- 12 044952 direction of light scattering.

Third level - macroscale elements

Most structured surfaces have a combination of light scattering, micro- and macrostructures, although a combination of light scattering and macrostructure can occur. Macrostructural elements are usually clearly visible to the naked eye, i.e. can be recognized as grains, slopes, cracks, holes, etc. Macrostructural elements do not affect the glossiness of the surface, but can influence its direction. Elements such as wood knots, wood grains, wood fibers, hairs, marble veins, etc. - all these are macro-scale elements.

To measure macro- and microstructure, a microscope can be used to see the micro- and macrostructure. Both optical and contact profilometers can be used to measure micro- and macrostructure.

Optical measurements are also used for micro- and macrostructures.

Surface roughness is usually at the microstructure level (at least in one direction), but can also extend to nanostructures, i.e. light-scattering structures.

In addition to micro- and nanoscale features, the wear layer may also contain macro-scale features visible to the naked eye. Since the varnish layer is transparent, the appearance of the floor panel can be determined by the varnish layer, wear-resistant layer and digital printing on the decorative layer. In addition, the appearance of the gloss or glosses from the wear layer may be combined with the gloss or glosses from the varnish layer.

In one embodiment according to the first aspect of the invention, the multi-layer top layer comprises a decorative layer comprising a chemically embossed relief design, a printed design applied in the form of single or stacked dots of digitally printed material over the decorative layer, and a mechanically embossed wear layer over the printed decorative layer. layer.

In a preferred embodiment, the floor panel has a surface structure in which macro-scale features are primarily chemically embossed in the decorative layer and micro- and nanoscale features are primarily mechanically embossed in the wear layer. This results in a surface structure consisting of sharp and fine micro- and nanoscale elements of a mechanically embossed wear layer superimposed on the rougher, more rounded macro-scale elements of a chemically embossed decorative layer. Thus, the natural appearance of the panel can be enhanced and even enhanced by fully or partially combining the mechanically embossed surface structure with a decorative printed design on the decorative layer. The inventors have discovered that in this way floor panels can be produced with a more realistic appearance and feel that successfully imitate the color, texture and sheen of the wood grain structure.

The floor panel may further include connecting parts for assembling multiple panels together (hereinafter referred to as a locking system). Locking systems have been widely used for many years and are well known in the art. The most popular locking systems are glueless locking systems, in which both horizontal and vertical locking of panels is accomplished using a tongue on one (edge) side and a groove on the opposite (edge) side of the panel. Typically, tongue and groove locking systems are manufactured integrally with the panel. An alternative locking system includes a plurality of staggered engagement tabs extending outward from the edges of the panel. Such a system is, for example, described in EP 3129567.

In addition, the floor panel may be chamfered along one or more of its side edges. Such chamfers are known in the art and can be created on the floor panel using any method known in the art. Traditionally, the bevel is milled into the finished floor panel at an angle of approximately 30°. The milling depth should preferably not exceed the thickness of the wear layer. Deeper milling removes the decorative print and exposes the underlying decorative layer, which gives an unnatural appearance to the chamfer and, as a result, often requires an additional finishing step. Additionally, standard routing processes create straight edges, which gives the bevel a more artificial appearance. The milling process also removes any layer of varnish that may be present on top of the wear layer. Removing the varnish makes the floor panel more susceptible to scratches and stains, resulting in a very glossy surface. The varnish layer can be a continuous or discontinuous, transparent layer that matches the mechanically and/or chemically embossed relief patterns to which it is applied.

In one embodiment, the floor panel includes a multi-layer top layer having a foamed decorative layer and a chemically embossed bevel along one or more side edges. A chamfer depression is formed where foaming is delayed. The amount of defoamer can vary across the width of the chamfer to produce a chamfer with a specific depth, shape and/or slope. In this way, greater design freedom can be achieved.

In another embodiment, the floor panel includes a multi-layer top layer having

- 13 044952 foamed decorative layer and one or more chemically embossed grout or grooves. Additionally, chemically embossed grout can be cut or milled down the middle to create a two-panel floor with beveled edges.

Another important advantage of a raised bevel or grout is that the final product retains a wear layer and, if desired, a varnish layer on top. This results in superior wear and scratch resistance compared to a milled bevel. The varnish layer may be a continuous or discontinuous transparent layer that matches the mechanically and/or chemically embossed relief patterns to which it is applied.

In addition, the embossed relief design can be optionally combined with a printed design to further optimize the aesthetics and natural appearance of the floor panel.

The floor panel may have a backing layer adjacent and bonded to the bottom surface of the base. The backing layer may comprise one layer or several layers. An underlayment can be applied to provide anti-slip properties to loose floors. The backing layer may contain a foam layer, for example, to improve acoustics or provide thermal insulation. The backing layer can be made of a synthetic material, such as extruded polyethylene. In a preferred embodiment, the backing layer contains polyvinyl chloride.

The PVC backing layer can be made as an extruded layer or as one or more fused layers of plastisol.

Method of manufacturing floor panels

In a second aspect, the present invention provides a method for manufacturing a floor panel in accordance with the first aspect of the invention, comprising the following steps:

S1: preparing the base,

S2: application of the first coating containing PVC plastisol directly onto the base to obtain a decorative layer,

S3: gelation of the decorative layer,

S4: applying a printed pattern of individual or stacked dots of printed material directly onto the gelled decorative layer using digital printing,

S5: Applying a second coating containing PVC plastisol to the printed decorative layer to obtain a wear-resistant layer,

S6: gelation of the wear-resistant layer and fusion of the decorative layer and the wear-resistant layer,

S7: Selective application of a varnish layer directly over the fused wear layer.

The multilayer top layer according to the first aspect of the invention is created in steps S2 to S7. The additional varnish layer can be a conformal layer, i.e. have the same thickness at all points of the wear layer. This makes it possible to transfer any relief pattern in the wear-resistant layer and/or decorative layer through the varnish layer. The optional varnish layer preferably corresponds to underlying macro-, micro-, or nanoscale surface relief patterns. The varnish layer can be applied as a continuous or discontinuous transparent layer that matches the mechanically and/or chemically embossed relief patterns to which it is applied. Since the varnish layer is transparent, the appearance of the floor panel can be determined by the varnish layer, wear-resistant layer and digital printing on the decorative layer. In addition, the appearance of the gloss or glosses from the wear layer may be combined with the gloss or glosses from the varnish layer.

In fig. 2 is a schematic illustration of a method for manufacturing a floor panel in accordance with the second aspect of the invention.

In the first step (S1), a base is provided as described herein, which can be, for example, a base made of a synthetic or composite material. In a subsequent step (S2), a first coating containing the PVC plastisol described herein is applied directly to the base to form a decorative layer. PVC plastisol coatings can be applied in a variety of ways, such as roller or spray application. In a preferred embodiment, the plastisol is applied with a roller. The decorative layer is then gelled at a temperature of 50 to 160°C, preferably at 150°C in an IR oven (S3). In the next step (S4), the printed pattern of individual or stacked dots of the printed material is applied directly onto the gel-like decorative layer using a digital printing technique, preferably inkjet printing. The printed design is preferably applied to a flat decorative layer with an appropriate surface temperature and surface energy for printing. The surface of the decorative layer ideally has ambient temperature. In a preferred embodiment, the printing material is a UV-curable inkjet ink. Once the ink droplets are applied to the desired design using an inkjet printer, the droplets are preferably at least partially cured using UV light. This will prevent further spreading of drops over the decorative layer and will allow you to quickly fix the print on the gel-like decorative layer. This allows you to quickly and accurately print the decorative layer. In another embodiment, the printed design is applied using laser printing. Similar to the use of inkjet printing in combination with UV-curable inks, laser printing allows you to quickly fix the print on the gel-like layer of the decor. In the present method, any ultraviolet light source can be used as the radiation source as long as a portion of the emitted light can be absorbed by a photoinitiator or photoinitiator system, such as a high or low pressure mercury lamp, a cold cathode tube, a black light, an ultraviolet LED, an ultraviolet laser, and a flash. Of these, a source producing relatively long-wave UV radiation with a predominant wavelength of 300-410 nm, more preferably an ultraviolet LED, is preferred. More specifically, a UVA light source, more preferably a UVA LED, is preferred due to reduced light scattering, resulting in more efficient and deeper curing. In the next step (S5), a second coating containing PVC plastisol is applied to the printed decor layer to obtain a wear-resistant layer. Preferably, the plastisol coating is applied using a roller coating machine. In the subsequent step (S6), the wear-resistant layer is gelled at a temperature ranging from 60 to 160°C, and then the decorative layer and the wear-resistant layer are fused at a temperature ranging from 160 to 200°C. The gelation and fusion process can, for example, be carried out in a convection oven. Optionally, the varnish layer described here can be applied directly over the fused wear layer (S7). Applying varnish to floor panels is well known in the art. The additional varnish layer can be a conformal layer, i.e. have the same thickness at all points of the wear layer. This allows any relief pattern in the wear-resistant layer and/or decorative layer to be transferred to the varnish layer. The additional varnish layer preferably matches any underlying elements of the embossed surface. The varnish layer can be applied as a continuous or discontinuous transparent layer that matches the mechanically and/or chemically embossed relief patterns to which it is applied.

Foaming the decorative layer

In a preferred embodiment, the first coating containing PVC plastisol is provided with one or more foaming agents to produce a foamable decorative layer. Foaming is initiated by heat treatment at the fusion stage (S6).

In another preferred embodiment, the foamable decorative layer is foamed and chemically embossed in a fusion step (S6). To achieve this, a pattern of single or stacked dots of printed material containing an antifoam is applied to the foamed decorative layer after it has been gelled in step 3. The surface of the foamed decorative layer ideally matches the ambient temperature. The printed material containing the defoamer is applied digitally, preferably by inkjet printing. The digital printed material containing the defoamer may also contain ink, but preferably does not contain it.

The inhibitor and ink can be applied to the foam layer during separate printing operations. In a preferred embodiment, the inhibitor and ink are printed in the same printing operation as the ink, resulting in a chemically embossed pattern and a digitally printed ink pattern forming a decorative image. The advantage is that the inhibitor dots and ink dots can be printed independently of each other. The printhead containing the defoamer is preferably combined with other ink-only printheads in a printhead array, wherein the defoamer and the ink are digitally printed as part of a single printing operation. The defoamer may be printed above, below, next to and/or between the ink dots.

After application, the foam inhibitor penetrates into the decorative layer and counteracts the formation/expansion of foam during heat treatment. Areas of the decorative layer that have not been printed with defoamer or that have not been penetrated by defoamer thus expand normally during heat treatment, while decorative expansion is suppressed or reduced in areas printed with defoamer, resulting in a surface with an intermittent chemically embossed relief pattern. with recesses. The resolution of the chemical embossing pattern is preferably in the range of 100 to 1200 dpi, more preferably 300 to 1000 dpi, even more preferably 360 to 600 dpi.

Moreover, the naturally occurring images can be scanned using an optical and/or laser scanning system and loaded into a database, thereby also taking into account the surface structure. Then, the structure and image can be further processed using image processing software, which can then be respectively applied as a chemical embossing pattern and a decorative printing pattern on the top surface of the foamed decorative layer using digital printing technology. Devices used for digital printing, such as an inkjet printer, can then be equipped with software that contains a database containing, for example, different types of wood or stone patterns and surface structures or any other decorative patterns.

- 15 044952

Mechanical embossing of wear-resistant layer

In a preferred embodiment, the wear-resistant layer is provided with a mechanically embossed surface structure. This is done by applying an embossing mold having a structured surface to the top surface of the still liquid wear layer before gelling begins. The liquid wear layer then still has sufficient fluidity to flow and adapt to the structured surface of the mold. The wear layer is gelled at temperatures between 50 and 160°C while the mold remains in contact with the surface of the wear layer. During this process, the surface texture of the mold is transferred to the surface of the wear layer. Preferably, the mold is removed from the wear layer after it has gelled. The mold can be removed at a later stage in the process, for example after the decorative layer and wear layer have fused (up to 200°C). The implemented embossed surface structure includes protruding areas and recesses.

The embossing mold preferably has a large surface area to reduce repetition and provide sufficient contact time for gelation.

The embossing form may include any of the following:

a) A fabric with a structured surface, such as foundry paper. The web may be infinite or may have a discrete length. To save money, foundry paper can be reused;

b) Rubber sleeve with a structured surface;

c) A tape with a structured surface, selectively coated with a non-stick material, for example PTFE;

e) A plate with a structured surface that can be placed on the coating to be embossed or the coating can be raised above it;

f) A structured cylinder or texture roller that can be used in a process similar to intaglio printing to convey surface structure.

The inventors have found that the process of this invention provides very efficient transfer of surface structure.

Preferably, the surface structure is matched to the characteristics of the digitally printed decor in order to provide a surface relief and a printed decor in the register.

In a preferred embodiment, the wear-resistant layer is provided with a mechanically embossed surface structure by means of a release web having a specific surface structure. The surface structure of the removable web includes micro- and nanoscale features and is a three-dimensional negative image of the desired surface structure, such as wood grain. The release web is laminated with its structured surface down onto the still liquid-resistant wear layer before gelation begins. In this case, the wear layer still has sufficient fluidity to flow and adapt to the structured surface of the release web. Preferably, the release web is pressed against the covering using a pressure roller or belt. The roller or belt is placed at a distance that ensures close contact between the web and the coating, at least during the gelation stage. Unlike traditional embossing processes, no additional pressure is required to ensure close contact and sufficient depth. The absence of additional pressure reduces the risk of destruction of the foam base during the embossing process. In addition, the removable fabric structure is capable of transforming the entire surface structure from nanoscale to macroscale. The wear layer gels at temperatures between 50 and 160°C while the release sheets remain in contact with the surface of the wear layer. The release web is preferably removed from the surface of the wear layer after the layer has gelled. For economic reasons, the removable sheet must be reusable. The removable web can also be made in the form of an endless tape that can be reused many times. Therefore, the process step of creating surface structures in the wear-resistant layer can be continuous. Preferably, the removable fabric is combined with a digitally printed pattern of the decorative layer.

The above functions require a release sheet with good temperature stability and thermal resistance as it is exposed to high temperatures during each gelation process (typically up to 160°C). The removable web can be removed at a later stage of the process, for example after the decorative layer and the wear layer have fused (up to 200°C). The removable sheet will then be exposed to higher temperatures for a longer period of time. This may limit the life of the blade and is therefore less preferable.

The structured release web has a surface that can be easily separated from either the gelled or fused plastisol layer. In a preferred embodiment, the release web comprises polymer-coated paper used for replica molding processes, commonly referred to as cast paper or release paper. The polymer coating of casting paper can be given different surface textures, such as different types of wood grain, using a precision engraving embossing roller. Casting paper is available,

- 16 044952 for example as Ultracast (Sappi) or as Favini Release Paper (Favini).

The inventors have found that mechanical embossing with a surface-structured removable fabric while gelling a wear-resistant layer based on a polyvinyl chloride plastisol coating allows the formation of very small parts, including nanoscale ones, regardless of depth or recesses.

In addition, the resulting wear layer containing fused plastisol was found to retain very fine (nanoscale) surface structures very well after removal of the release web. In addition, the relatively large surface area of the removable structured surface reduces the repetition of the relief pattern, which contributes to the natural appearance of the floor panel.

The appearance of the floor panel can be further improved by combining a chemically embossed decorative layer with a mechanically embossed wear layer.

In another embodiment, the varnish is transferred to the wear layer while the latter is mechanically embossed (during S6). Wet varnish is applied to the structured surface of the embossing plate, preferably a release sheet, prior to the embossing process. The embossing mold containing the wet varnish is brought into contact with the still wet second plastisol layer during the embossing step (S6). The mold is removed, and the varnish remains on the embossed wear-resistant layer. This provides an alternative to process step S7. The varnish layer may be a continuous or discontinuous transparent layer that matches the mechanically and/or chemically embossed relief patterns to which it is applied.

Example 1 Floor panel according to the invention

The 3.3 mm thick, 1150 kg/m ³ extruded foam panel core is prepared from the following raw materials: 14.75 wt.% s-PVC K-value 57 (Inovyn™ PVC 257RF from Inovyn), 19.97 wt.% micronized recycled PVC (EvervinylTM from Paprec), 26.68 wt.% recycled material containing PVC (waste from grinding and grinding of Pure Click products, BerryAlloc), 2.95 wt.% calcium carbonate (OmyaliteTM 95 T from Omya), 30 .25 wt.% talc (CM3 from IMI Fabi), 0.64 wt.% stabilizer (CVG 53349/32 from Chemson), 0.74 wt.% processing aid (PA650 from Kaneka), 0.03 wt.% synthetic wax (AC 316 A from Honeywell), 1.8% stabilizer (NaftosafeTM TRX 722 A4 from Chemson), 0.9 wt.% blowing agent (Zebra-cell C016K-10 from Zebra-chem), 0.89% impact modifier ( CPE TYR7100 from Ravlek) and 0.4 wt% carbon black (GP N0299 from Viba). The formed base has a top surface and a bottom surface. The base thickness in this example ranges from 2.4 to 5.8 mm.

2. 400 µm of the first plastisol coating, which contains 12.62 wt.% s-PVC with a K-value of 66 (SolvinTM 266SF from Solvin), 21.03 wt.% microsuspension-PVC with a K-value of 67 (SolvinTM 367NF from Solvin) , 8.41 wt.% microsuspension-PVC grade with a K value of 70 (B7021 from Vestolit), 7.57 wt.% dioctyl terephthalate, 4.21 wt.% isodecyl benzoate (BenzoflexTM 2088 from Velsicol), 6.73 wt.% plasticizer (JayflexTM MB10 from ExxonMobil), 35.73 wt.% chalk (MicrodolTM A200 from Omya), 2.86 wt.% titanium dioxide (K2900 from Kronos) and 0.84 wt.% viscodepressant (AviVisco 210 from Avivan) are applied directly onto the top surface of the base using a reverse roller coater (e.g. easy-Coater RCLM-M 1600 from Biirkle) to obtain a decorative layer.

3. The decorative layer is gelled for 25 s at a temperature of 150°C using an IR oven (short wave, 50 kW/ ^m2 ).

4. The base with the decorative layer is cooled for 25 minutes at an ambient temperature of 22°C.

5. The decorative layer is applied using UV-curable inks using inkjet printing.

6. 700 μm of a second plastisol PVC coating containing 10.26 wt.% s-PVC with a K value of 66 (SolvinTM 266SF from Solvin), 41.03 wt.% microsuspension-PVC grade with a K value of 82 (SolvinTM 382NG from Solvin ), 17.11 wt.% microsuspension - PVC grade with a K value of 90 (P1430K90 from Vestolit), 16.40 wt.% dioctyl terephthalate, 8.20 wt.% benzoic acid ester (BenzoflexTM 2088 from Velsicol), 3.40 wt.% isodecyl benzoate (JayflexTM MB10 from ExxonMobil), 0.9 wt.% deaerating agent (Avi Aero 022 from Avivan) and 2.7 wt.% Ca-Zn stabilizer (CLX759/5PF from Reagens), applied to the printed decorative layer using a reverse roll coater (e.g. e.a.sy-Coater RCLM-M 1600 from Burkle) to obtain a wear-resistant layer.

7. Structured release paper (Ultracast®, Sappi) is laminated into a liquid wear layer. The decorative layer and wear layer with laminated release paper are fused for 120 s at 195°C using a convection oven (eg Mathis oven).

8. The product is allowed to cool at an ambient temperature of 22°C for 35 minutes.

9. The structured release paper is removed from the product.

The multilayer top layer according to the first aspect of the invention is created in steps 2-9. The decorative layer of this layer is in the range from 0.10 to 0.70 mm. The thickness of this wear-resistant layer is from 0.10 to 1.00 mm, more preferably from 0.10 to 0.70 mm and most preferably from 0.20 to 0.70 mm.

The multi-layer top layer does not contain a reinforcing layer. The base does not contain a reinforcing layer. Floor panels do not contain interlayer adhesive material. Adhesive-free intermediate layers are located between the base and the decorative layer, the decorative layer and the wear-resistant layer and between the wear-resistant layer and the optional varnish layer.

Example 2 Floor panel according to the invention

The floor panel was manufactured in accordance with example 1, except that in step 2 a first plastisol coating of 200 μm thickness was applied. The thickness of the decorative layer ranged from 0.10 to 0.7 mm.

Example 3. Floor panel with foamed decorative layer according to the invention

The floor panel was manufactured in accordance with Example 1, except that the first plastisol coating containing 10.82 wt.% suspension PVC with a K value of 66 (SolvinTM 266SF from Solvin), 18.03 wt.% microsuspension grade PVC with a K value 67 (SolvinTM 367NF from Solvin), 7.21 wt.% microsuspension-PVC grade with a K value of 70 (B7021 from Vestolit), 15.3 wt.% dioctyl terephthalate, 2.88 wt.% benzoate ether (BenzoflexTM 2088 from Velsicol) , 3.61 wt.% isodecyl benzoate (JayflexTM MB10 from ExxonMobil), 36.03 wt.% chalk (MicrodolTM A200 from Omya), 3.94 wt.% titanium dispersion, 0.94 wt.% blowing agent (UnifoamTM AZ CP022 from Hebron), 0.02 wt.% wetting and dispersant additive (Disperplast 1148 from BYK), 0.14 wt.% deaerating agent (AviAero 022 from Avivan) and 1.08 wt.% viscodepressant (AviVisco 210 from Avivan), apply at stage 2 to obtain a foamed decorative layer. The foamable decorative layer is foamed during the fusion process in step 7.

Comparative samples

Comparative Sample A is a calendered floor panel comprising a PVC foam core, a PVC decorative layer, and a PVC wear layer. The floor panel additionally contains a protective layer of IXPE (irradiated cross-linked polyethylene).

Comparative Sample B is a floor panel consisting of a base made of PVC foam and a top layer made of printable PVC film and a wear-resistant PVC layer. The floor panel additionally contains a protective layer of cork.

Comparative Sample B is a calendered floor panel consisting of a PVC base and a printed PVC wear layer.

Comparative sample D is a floor panel containing a base of polyurethane material, decorative paper and a top polyurethane layer with a surface structure. The floor panel additionally contains a protective layer made from the Integrated Fleece TEC system.

Comparative Sample E is a floor panel comprising the backing of Example 1 attached to a shock-absorbing vinyl layer with a total thickness of 1.55 mm. The vinyl cushion contains a layer of fiberglass.

Modulus of elasticity of floor panels in accordance with the invention

The laminated top layers of the floor panels of Examples 1-3 and Comparative Samples A-D were separated from their bases using a cutter and/or pliers. The modulus of elasticity of the base floor panels of examples 1-3 and comparative samples A-D was measured at a temperature of 23 ± 2°C and relative humidity of 50 ± 10% in accordance with ISO 527-2: 2012. Modulus of elasticity of the multi-layer top layers of the floor panels of the examples 1 and 3 and comparative samples A-D were measured at a temperature of 23 ± 2°C and a relative humidity of 50 ± 10% in accordance with the ISO 527-2:2012 standard. The modulus of elasticity of the laminated top layer of the floor panel of Example 2 was measured at a temperature of 23 ± 2°C and a relative humidity of 50 ± 10% in accordance with ISO 527-3:2018. All test specimens were cut or punched to the size of Type 1B specimens. The testing speed of the tensile testing machine was maintained at 1 mm/min.

The relationship between the elastic moduli of the base and the multilayer top layer was calculated.

Table 1. Elastic moduli of the base and multilayer top layer

Cover panel elastic modulus ratio between elastic moduli the basis Multi-layer top layer Example 1 2800 MPa 39 MPa 71.8 Example 2 2800 MPa 36 MPa 77.8 Example 3 2800 MPa 32 MPa 87.5

- 18 044952

Comparative Sample A 1293 MPa 155 MPa 8.3 Comparative sample B 473 MPa 226 MPa 2.1 Comparative Sample B 116 MPa 88 MPa 1.3 Comparative sample D 121 MPa 1040 MPa 0.1 Comparative sample D 2800 MPa 134 MPa 20.9

Definition: Hot Twist and Cold Twist

The vertical deformations of the floor panels of Examples 1-3 and comparative floor panels (Comparative Samples A-E) containing one or more laminated or calendered films were determined after specific heat or cold treatments.

For each torsion test, three square specimens (24 x 24 cm) were cut from the floor panel or board for testing. The edges of the sample were cut parallel or across the direction of the product. Test specimens were conditioned at 23°C +/- 2°C and 50% +/-5% relative humidity for a minimum of 24 hours.

For the hot torsion test, the specimens were placed horizontally on preheated steel support plates (50 ± 3°C) with the wear layer of the specimen facing up. The steel support plates are larger than the test sample and are 1.5 mm thick.

The vertical distances between the steel backing plate and the wear surface at the four corners of the test specimens (distance t1 to t4) were measured. Distances were measured with a caliper with a division value of 0.01 mm.

Test specimens were placed in an oven and allowed to reach a temperature of 50 +/- 3°C for 1 hour. The oven was thermostatically controlled and ventilated to maintain an even temperature.

The samples were removed from the refrigerator. The samples were not reconstructed or directly measured. The vertical distance between the backing plate and the wear surface of the test specimens was measured at the four corners of each specimen (distances u1 to u4). The samples were rotated and placed wear-resistant layer down on steel support plates. The vertical distances were again measured at the four corners (distances d1 to d4).

To calculate the curl of each sample, it was first determined whether the sample was curling up or down by comparing the average value of u1-u4 with the average value of d1-d4. If the average upward facing distance (u1-u4) was greatest, then the specimen curl was calculated by subtracting the average thickness (average t1-t4) from the average u1-u4. If the average d1-d4 was the largest, the average curl was determined by subtracting the average d1-d4 from t1-t4 to obtain a negative value, which represents the downward curl of the specimen.

For the cold torsion test, specimens were placed horizontally on pre-cooled steel support plates (5 +/- 1°C). The refrigerator is equipped with thermostatic controls to maintain an even temperature. The steel support plates are larger than the test piece and 1.5 mm thick.

Test samples were placed in a refrigerator and allowed to warm to a temperature of 5 +/- 1°C. The samples were kept at this temperature for 24 hours.

The samples were removed from the refrigerator. The samples were not reconstructed or directly measured. The vertical distance between the backing plate and the wear surface of the test specimens was measured at the four corners of each specimen (distances u1-u4). The samples were rotated and placed wear-resistant layer down on steel support plates. The vertical distances were again measured at the four corners (distances d1 to d4).

To calculate the curl of each sample, it was first determined whether the sample was curling up or down by comparing the average value of u1-u4 with the average value of d1-d4. If the average upward facing distance (u1-u4) was greatest, then the specimen curl was calculated by subtracting the average thickness (average t1-t4) from the average u1-u4.

If the average d1-d4 was the largest, the average curl was determined by subtracting the average d1-d4 from t1-t4 to obtain a negative value, which represents the downward curl of the specimen.

Finally, the vertical deformations of the panels were determined by taking the average of three samples. Vertical deformations caused by hot or cold torsion are shown in Table. 2.

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Claims (31)

Results in table. 2 show that the cover panels in accordance with the present invention (Examples 1-3) perform very well in both the hot curl test and the cold curl test. Comparative samples A-B performed well in the hot curl test, but showed significant curl in the cold curl test. Comparative sample G-D performed poorly in both the hot curl test and the cold curl test. Table 2. Curling of floor panels after exposure to heat or cold Warm twist(mm) Cold twist(mm) Example 1 -0.07 -0.06 Example 2 -0.02 0.08 Example 3 -0.04 0.25 Comparative Sample A 0.09 1.08 Comparative sample B -0.07 0.58 Comparative Sample B 0.07 0.51 Comparative sample D 0.55 0.47 Comparative sample D -1.29 -0.75 CLAIM 1. Floor panel containing the base; multi-layer top layer directly attached to the base; wherein the multilayer top layer contains a decorative layer consisting of fused PVC plastisol, a printed pattern applied in the form of single or stacked dots of digitally printed material on top of the decorative layer, a wear-resistant layer consisting of fused PVC plastisol applied on top of the printed pattern, characterized in that the wear-resistant layer is obtained by gelation of PVC plastisol and mechanical embossing of PVC plastisol during gelation and subsequent fusion of the gel-like PVC plastisol to obtain a fused wear-resistant layer. 2. The floor panel according to claim 1, characterized in that it additionally contains a varnish layer applied directly on top of the wear-resistant layer. 3. Floor panel according to claim 1 or 2, characterized in that the ratio between the modulus of elasticity of the base and the multi-layer top layer is at least 20, measured at a temperature of 23±2°C and a relative humidity of 50±10% in accordance with ISO 527 . 4. Floor panel according to any one of claims 1 to 3, characterized in that the multi-layer top layer has an elastic modulus of less than 100 MPa at 23°C, measured at a temperature of 23±2°C and a relative humidity of 50±10%, in accordance with ISO 527. 5. Floor panel according to any one of claims 1 to 4, characterized in that the base has an elastic modulus of more than 2000 MPa, measured at a temperature of 23±2°C and a relative humidity of 50±10% in accordance with ISO 527. 6. Floor panel according to any one of claims 1-5, characterized in that the multi-layer top layer does not contain a reinforcing layer. 7. Floor panel according to any one of claims 1-6, characterized in that the base does not contain a reinforcing layer. 8. Floor panel according to any one of claims 1-7, characterized in that the floor panel does not contain interlayer adhesive material. 9. Floor panel according to any one of claims 1-8, characterized in that the base is a foam base. 10. Floor panel according to any one of claims 1 to 9, characterized in that the base is a single-layer base. 11. Floor panel according to claim 9 or 10, characterized in that the density of the foam base is equal to or - 20 044952 less than 1600 kg/m ³ , more preferably less than 1400 kg/m ³ , even more preferably less than 1300 kg/m ³ and a density equal to or greater than 400 kg/m ³ , more preferably more than 600 kg/m ³ , even more preferably greater than 800 kg/m ³ and most preferably greater than about 1000 kg/m ³ . 12. Floor panel according to claim 11, characterized in that the density is in the range from 1050 to 1300 kg/m ³ , more preferably from 1100 to 1200 kg/m ³ . 13. Floor panel according to any of the previous paragraphs, characterized in that the base has a thickness of from 1 to 25 mm, preferably the base has a thickness of from 1.5 to 20 mm and more preferably from 1.5 to 7 mm, and even more preferably from 2.4 to 5.8 mm. 14. The floor panel as claimed in any one of the preceding claims, wherein the base has a glass transition temperature (Tg) of 80°C or higher, and more preferably a glass transition temperature (Tg) of 85°C or higher. 15. The floor panel according to any one of claims 1 to 14, characterized in that the decorative layer contains a chemically embossed relief pattern formed by single or stacked dots of digitally printed material containing an antifoam agent. 16. Floor panel according to any of the previous paragraphs, characterized in that the thickness of the decorative layer is in the range from 0.1 to 0.7 mm. 17. Floor panel according to any one of claims 1 to 16, characterized in that the wear-resistant layer has a surface structure with mechanical embossing. 18. Floor panel according to any one of claims 15-17, if it depends on claims 2-16, characterized in that the varnish layer is a continuous or discontinuous transparent layer that corresponds to a mechanically and/or chemically embossed relief pattern. 19. Floor panel according to claim 18, characterized in that the varnish layer corresponds to the wear-resistant layer. 20. The floor panel of any one of the preceding claims, characterized in that it comprises a surface with varying levels of gloss, including first high gloss zones, second silky gloss zones and third matte zones. 21. Floor panel according to claim 20, characterized in that the surface has macro-, micro- and nanoscale elements. 22. The floor panel of claim 20 or 21, wherein one or more areas of the panel surface that have gloss values or macro-, micro-, and nanoscale features are aligned with one or more portions of the printed pattern. 23. The floor panel according to any one of claims 1 to 22, characterized in that the peel resistance of the base from the multi-layer top layer is at least 50 N/50 mm, as determined by the peel test and determined in the present invention. 24. A method for manufacturing a floor panel, including the following steps: S1: providing the basis, S2: application of the first coating containing PVC plastisol directly onto the base to obtain a decorative layer, S3: gelation of the decorative layer, S4: applying a printed pattern of single or stacked dots of printed material directly onto a gelled decorative layer using digital printing, S5: applying a second coating including PVC plastisol to the printed decorative layer to obtain a wear-resistant layer, S6: gelling the wear layer and then fusing the decorative layer and the wear layer, further including a step of mechanically embossing the wear layer during gelation. 25. The method according to claim 24, further comprising step S7: applying a varnish layer directly on top of the renowned wear-resistant layer. 26. Method according to claim 25, characterized in that the varnish layer corresponds to the wear-resistant layer. 27. Method according to claim 25 or 26, characterized in that the varnish layer is a continuous or discontinuous transparent layer corresponding to a mechanically and/or chemically embossed relief pattern. 28. A method for manufacturing a floor panel according to any one of claims 24-27, characterized in that the floor panel does not contain interlayer adhesive material. 29. A method for manufacturing a floor panel according to any one of claims 24-28, characterized in that the base is a foam base. 30. A method for manufacturing a floor panel according to any one of claims 24-29, characterized in that the base is a single-layer base. 31. A method for manufacturing a floor panel according to any one of claims 24-30, further comprising the following steps: introducing a foaming agent into the first coating to obtain a foamable decorative layer in step S2; drawing a pattern from single or stacked dots of printed material, co-