Decorative panel and method for manufacturing decorative panel

Abstract

Decorative panel comprising a substrate (2) and a top layer (3) disposed thereon, where the substrate (2) comprises at least a semi-crystalline polymer (4), characterized in that the decorative panel (1) exhibits one or a combination of two or more of the following properties:-the crystallinity of the polymer is less than 85% as measured using differential scanning calorimetry; -the crystallinity of the polymer is higher than 35%, preferably higher than 50%; -the polymer is of a uniaxially oriented property; -the top layer comprises a semi-crystalline polymer, wherein the crystallinity of the polymer comprised in the substrate (2) is lower than the crystallinity of the polymer comprised in the decorative top layer (3); -said substrate (2) comprises a plurality of substrate layers, wherein at least two of said plurality of substrate layers comprise the properties of a semi-crystalline polymer (4).

Description

Technical Field

[0001] The invention relates to a decorative panel and a method for producing a decorative panel. The decorative panel of the invention is firstly suitable for application as a floating floor panel, but can also be used in other ways, for example as a glued floor panel, or as a wall or ceiling panel. Background Art

[0002] WO 97 / 47834 describes laminate floor panels for assembling floating floor coverings. As described therein, this floor panel has the disadvantage that the applied substrate, more particularly an MDF or HDF substrate (medium density fiberboard or high density fiberboard), is susceptible to moisture damage. The laminate top layer may emit walking and / or ticking noises.

[0003] EP 1 938 963 discloses a floor based on synthetic material, more specifically soft polyvinyl chloride (PVC). The floor can be obtained at least by laminating several synthetic foils. EP 3 405 346 discloses a floor panel of high-density filled polyvinyl chloride material. The floor panel can be obtained at least by extrusion. In both EP'963 and EP'346, the floor is provided with a decorative top layer comprising PVC. The floor panels of EP'963 and EP'346 may be more waterproof than the panels of WO'834, and / or provide more comfortable walking and / or ticking. However, the use of PVC, plasticizers and / or other additives may, at least in some cases, be harmful to the environment.

[0004] According to WO 2017 / 122149, it is known to use a PET (polyethylene terephthalate) composition as a substrate in a floor panel, wherein the substrate can be formed at least by extrusion. According to WO 2014 / 111192, it is known to use a thermoplastic composition comprising PP (polypropylene) as a substrate in a decorative panel. Panels comprising a substrate using PET or PP, due to their crystallinity, may be particularly susceptible to deformation under changing environmental conditions. Summary of the invention

[0005] The present invention firstly seeks to provide an alternative decorative panel, wherein, according to preferred embodiments, a solution is provided to one or more problems of prior art decorative panels.

[0006] To this end, according to its first independent aspect, the present invention is a decorative panel comprising a substrate and a top layer arranged thereon, wherein the substrate comprises at least a semi-crystalline or crystalline polymer and / or a polymer selected from the list consisting of polyacetal (POM), polyphenylene sulfide (PPS), polyamide (such as PA 6 and PA 66), polyethylene terephthalate (PET), glycol-modified PET (PETG), polycyclohexanedimethylene terephthalate (PCT), glycol-modified polycyclohexanedimethylene terephthalate (PCTG), polycyclohexanedimethylene terephthalate (PCTA), polyethylene (PE), low-density polyethylene (LDPE) (e.g. linear low-density polyethylene (LLDPE)), high-density polyethylene (HDPE), polybutylene terephthalate (PBT), polylactic acid (PLA), polyetheretherketone (PEEK) and polypropylene (PP), characterized in that the decorative panel exhibits one or a combination of two or more of the following properties.

[0007] According to a first possible property, the polymer has a crystallinity lower than 95% or lower than 85%, preferably measured using differential scanning calorimetry (DSC) according to ISO 11357-3: 2018. By limiting the crystallinity, the dimensional instability of the decorative panel as a whole can be kept within acceptable limits.

[0008] According to a second possible property, the polymer has a crystallinity higher than 35%, preferably higher than 50%, preferably measured using differential scanning calorimetry (DSC) according to ISO 11357-3:2018. Allowing a minimum crystallinity can be beneficial to the toughness, tensile strength of the substrate and the chemical resistance of the substrate. The first and second possible properties are preferably combined to obtain an optimized crystallinity according to the desired properties of the decorative panel (e.g. floor panel) while maintaining good dimensional stability.

[0009] According to the third possible property, the polymer is uniaxially oriented, or oriented in at least one direction. The polymer chains are mainly oriented in at least one direction, which may lead to an increase in tensile strength in the corresponding direction. The orientation direction preferably coincides or roughly coincides with the maximum dimension of the decorative panel. For example, in the case of rectangular and oblong panels, the orientation direction preferably coincides or roughly coincides with the longitudinal direction of the decorative panel. In this case, stresses caused by dimensional instability can be best dealt with because it can be expected that shrinkage or expansion will be the largest in the longitudinal direction. When the third property is practiced in combination with at least the first possible property and potentially with the second possible property, the remaining properties (expected to be dimensional instability) can be managed.

[0010] Dimensional instabilities can be further limited by using filler materials, for example by using wollastonite, mica, aluminum silicate and / or glass, preferably in fiber form, and / or by using thermochemical pulp fibers. Preferably, the filler material is anisotropic in terms of its mechanical properties, in particular its tensile strength. Preferably, the filler material is generally oriented so that the direction of its maximum tensile strength coincides or approximately coincides with the orientation direction of the semi-crystalline or crystalline polymer and / or with the longitudinal direction of the rectangular and oblong decorative panels. Preferably, the ratio of the tensile strength values ​​in the orthogonal directions of the filler material is at least 125%, or at least 200%.

[0011] According to a fourth possible property, the top layer comprises a crystalline or semi-crystalline polymer, wherein the crystallinity of the polymer contained in the substrate is lower than the crystallinity of the polymer contained in the decorative top layer, or vice versa. Preferably, the difference in crystallinity between the polymer in the decorative top layer and the polymer in the substrate is at least 5% or at least 10%. This property limits the possible dimensional changes, in particular when the layer with the greatest crystallinity and therefore the layer with the highest expected dimensional instability, such as the decorative top layer, may and preferably is thinner than the substrate. According to the fourth possible property, the substrate can thereby stabilize the decorative top layer to a certain extent, and vice versa. Preferably, the decorative panel also includes a layer located at the bottom of the substrate, wherein the layer also includes a semi-crystalline or crystalline polymer and preferably has a higher crystallinity than the substrate, or vice versa. In this case, this layer can offset to a certain extent any warping effect caused by the different (e.g., higher) dimensional instability of the decorative top layer compared to the substrate. Preferably, the crystallinity of the layer applied to the bottom of the substrate is the same as the crystallinity of the decorative top layer, or is within 10% or 5% of the crystallinity of the decorative top layer, and / or the thickness of the layer applied to the bottom of the substrate is the same as the crystallinity of the decorative top layer, or is within 10% or 5% of the thickness of the decorative top layer. In this case, the best equalization effect can be achieved. This fourth possible property is preferably combined with the first, second and / or third properties. Preferably, the crystalline or semi-crystalline polymer contained in the decorative top layer and / or the layer applied to the bottom of the substrate is at least uniaxially oriented, and preferably biaxially oriented. The decorative top layer and / or the layer applied to the bottom of the substrate may include, for example, oriented polypropylene or polyethylene foil. In the case of this fourth possible property at least in combination with the third possible property, the polymer of the decorative top layer and / or the bottom layer may be oriented at least in a direction perpendicular to the orientation of the semi-crystalline polymer contained in the substrate, wherein the orientation of the semi-crystalline polymer contained in the substrate is preferably uniaxially oriented, or mainly oriented in a single direction. For example, in the case of rectangular and oblong panels, the substrate polymer material may be oriented at least or predominantly in the longitudinal direction, while the decorative layer and / or base layer may comprise a foil biaxially oriented in the longitudinal and transverse directions of the panel. In this case, the combination of the third and fourth possible properties produces a desirable synergistic effect in terms of enhanced dimensional stability of the decorative panel as a whole.

[0012] The decorative top layer preferably comprises a foil with a printed ink pattern. Preferably at least the foil comprises a crystalline or semi-crystalline polymer that complies with the fourth possible property. The decorative top layer preferably also comprises a wear layer applied on top of the printed ink pattern. The wear layer preferably comprises an amorphous polymer or a polymer with a crystallinity of less than 35% or less than 10%. Preferably the polymer of the wear layer is of the same polymer type as the foil. For example, the wear layer may comprise amorphous or atactic polypropylene, while the foil comprises semi-crystalline, crystalline or syndiotactic or isotactic polypropylene, for example with an isotactic index of 85%-95%. The isotactic index can be measured according to DIN 16774, for example, by determining the fraction of polymer that is insoluble in boiling heptane.

[0013] According to a particular embodiment, the decorative top layer comprises a printed foil, for example a polypropylene printed foil, and a transparent wear layer cast thereon, the wear layer comprising polypropylene, which is preferably embossed.

[0014] According to a specific possible property, the decorative panel comprises a top layer and / or a layer applied to the bottom of the substrate, wherein the top layer and / or the bottom layer comprises amorphous polypropylene or a polypropylene having a crystallinity of 35% or less, and / or wherein the top layer and / or the bottom layer is obtained by casting polypropylene. This specific property can minimize the warping effect caused by the top layer and / or the bottom layer. For example, the top layer can comprise cast PP, such as a cast PP foil, and a decorative print and / or a wear layer comprising cast PP is provided thereon, such as a cast PP film. Such cast PP is mainly non-oriented and minimizes the occurrence of directional stability effects caused by the top layer. Preferably, the bottom layer also comprises cast PP, such as a cast PP foil. Preferably, the wear layer comprising PP according to the specific properties of the present invention also comprises an amorphous polymer or copolymer, such as a cycloolefin polymer or copolymer (COP or COC). Such a blend of PP and an amorphous polymer or copolymer can improve the transparency of the wear layer.

[0015] According to a fifth possible property, the substrate comprises a plurality of substrate layers, wherein at least two of the plurality of substrate layers comprise a semi-crystalline polymer and / or a polymer selected from the list consisting of polyacetal (POM), polyphenylene sulfide (PPS), polyamides (such as PA 6 and PA 66), polyethylene terephthalate (PET), glycol-modified PET (PETG), polycyclohexane dimethyl terephthalate (PCT), glycol-modified polycyclohexane dimethyl terephthalate (PCTG), polycyclohexanedimethylene terephthalate (PCTA), polyethylene (PE), low-density polyethylene (LDPE), high-density polyethylene (HDPE), polybutylene terephthalate (PBT), polyetheretherketone (PEEK) and polypropylene (PP). Such polymers are arranged in a multilayer manner within the substrate so that any adverse effects, such as shrinkage and / or expansion, are optimally addressed. Preferably, the semi-crystalline polymers in the at least two substrate layers are identical, or at least constructed from the same monomers. Preferably, the other components of the corresponding two substrate layers are similar or identical and are present in similar or identical amounts. For example, both substrate layers may contain filler materials (preferably in the same or approximately the same ratio). Preferably, in the fifth property, the at least two substrate layers are separated from each other by an additional layer comprising a polymer (a semi-crystalline or crystalline polymer or another polymer, such as PVC). Alternatively or in combination, the at least two substrate layers may be separated by at least one reinforcing layer, or may include a reinforcing layer at their mutual interface surface. Preferably, in the fifth property, the number of polymer-containing substrate layers is preferably an odd number, for example, three or five. Preferably, the at least two substrate layers comprising semi-crystalline or crystalline materials are positioned equidistant or approximately equidistant from the center of the substrate as seen in the thickness direction with at least one of their main surfaces. Preferably, the at least two substrate layers comprising the semi-crystalline or crystalline materials have equal thickness, or approximately equal thickness, for example, with a thickness difference in which the thinnest layer is at least 90% of the thickness of the thickest layer.

[0016] According to a specific preferred embodiment of the fifth possible property, the at least two substrate layers may be included in a substrate having essentially an AB or ABA configuration, wherein A represents a layer having a first composition and B represents a layer having a second composition. As explained in the context of the fifth possible property, the two substrate layers may have the same or similar composition, or may have mutually different compositions, and thus may each form an A layer, or one of the two substrate layers may form an A layer and the other may form a B layer. For example, the two substrate layers may have mutually different compositions, for example, the composition difference may be at least or mainly related to different filler contents. In fact, the substrate layer may include a first substrate layer having a first composition comprising a semi-crystalline or crystalline material and / or a polymer selected from the list consisting of polyacetal (POM), polyphenylene sulfide (PPS), polyamide (such as PA 6 and PA 66), polyethylene terephthalate (PET), ethylene glycol-modified PET (PETG), polycyclohexanedimethylene terephthalate (PCT), ethylene glycol-modified polycyclohexanedimethylene terephthalate (PCTG), polycyclohexanedimethylene terephthalate (PCTA), polyethylene (PE), low-density polyethylene (LDPE), high-density polyethylene (HDPE), polybutylene terephthalate (PBT), polyetheretherketone (PEEK) and polypropylene (PP), and a first content of filler material (for example, a weight ratio of filler to polymer greater than 1.5:1, or even 2:1, 2.5:1 or more), and a second substrate layer having a semi-crystalline or crystalline material and / or a polymer selected from the list consisting of polyacetal (POM), polyphenylene sulfide (PPS), polyamide (such as PA 6 and PA 66). The second substrate layer comprises a second composition of a polymer selected from the list consisting of polyethylene (PE), low density polyethylene (LDPE), high density polyethylene (HDPE), polybutylene terephthalate (PBT), polyetheretherketone (PEEK) and polypropylene (PP) and a first content of filler material (e.g., a weight ratio of filler to polymer of 1.5:1 or less). The polymers of the two sub-layers may be the same, for example, both are polypropylene or both are PET or both are PETG. Preferably, the substrate consists essentially of or consists of the two sub-layers, thereby obtaining a substrate having an AB configuration, wherein the A layer or the first layer formed from the first composition is preferably closer to the top layer than the B layer or the second layer formed from the second composition, and / or wherein the A layer constitutes more than half of the thickness of the substrate. The inventors have noticed that this particular combination of a highly filled substrate layer with a less filled substrate material is particularly advantageous for minimizing warping effects due to polymer crystallinity.

[0017] In the fifth possible property, and in other embodiments where the substrate comprises a plurality of substrate layers, these layers may be bonded, heat laminated, coextruded or hardened to each other, with an intermediate layer of a primer layer or adhesive layer, as further described herein. Any combination of these techniques may be applied to the substrate layer.

[0018] Preferably the semi-crystalline or crystalline polymer is a thermoplastic polymer.

[0019] When the polymer is a polypropylene, such as semicrystalline or crystalline polypropylene, preferably a polypropylene having an isotactic index of 85% to 95% is used. The isotactic index can be measured according to DIN 16774, for example by determining the fraction of polymer insoluble in boiling heptane.

[0020] The substrate or the corresponding substrate layer comprising the semi-crystalline polymer preferably consists of a filled synthetic material or consists essentially of it, for example consists of more than 85 wt % of such a filled synthetic material. In this case, the synthetic material is preferably mainly or only formed by the semi-crystalline or crystalline polymer, for example more than 85 wt %, wherein the semi-crystalline or crystalline polymer is preferably a thermoplastic polymer or is formed by a polymer selected from the list consisting of polyacetal (POM), polyamide (PA 6 and PA 66), polybutylene terephthalate (PBT), polyethylene terephthalate (PET), glycol-modified polyethylene terephthalate (PETG), low-density polyethylene (LDPE), high-density polyethylene (HDPE), polyphenylene sulfide (PPS) and polypropylene (PP).

[0021] As an alternative to or in combination with the polymers already mentioned, the substrate or the corresponding layer may at least comprise a thermoplastic elastomer, such as a polymer or copolymer, for example a styrene block copolymer, wherein the polymer or copolymer comprises or consists of ethylene propylene-diene-monomer (EPDM), styrene-ethylene-butadiene-styrene (SEBS), poly(styrene-butadiene-styrene) (SBS), polyether block amide (PEBA), thermoplastic polyurethane (TPU), styrene-ethylene-propylene-styrene (SEPS), styrene-ethylene-ethylene-propylene-styrene (SEEPS), acrylonitrile-ethylene-styrene (AES) or polybutadiene (PB), preferably in semi-crystalline or crystalline form and / or according to the first to fifth and specific possible properties mentioned above. Alternatively, the substrate or the corresponding layer may at least comprise polystyrene (PS) (preferably atactic polystyrene), ABS, chloroprene rubber or polyvinyl alcohol (PVAC), preferably in semi-crystalline or crystalline form and / or according to the first to fifth and specific possible properties mentioned above.

[0022] The substrate may include a reinforcement layer, such as a woven or nonwoven reinforcement layer, such as a glass fiber woven or nonwoven layer. The semi-crystalline or crystalline polymer may be continuously passed through the openings of the reinforcement layer, such as through an interlaced glass fiber woven layer, for example a woven layer having a mesh structure of glass fibers extending in at least two cross directions.

[0023] Preferably, the semi-crystalline polymer is selected from the list consisting of polyacetal (POM), polyamide (PA 6 and PA 66), polybutylene terephthalate (PBT), polyethylene terephthalate (PET), glycol-modified PET (PETG), polycyclohexane dimethyl terephthalate (PCT), glycol-modified polycyclohexane dimethyl terephthalate (PCTG), polycyclohexanedimethylene terephthalate (PCTA), low-density polyethylene (LDPE), high-density polyethylene (HDPE), polyphenylene sulfide (PPS) and polypropylene (PP). The semi-crystalline polymer may be a homopolymer or a heteropolymer, preferably having a main component of one of polyacetal (POM), polyamide (PA 6 and PA 66), polybutylene terephthalate (PBT), polyethylene terephthalate (PET), low-density polyethylene (LDPE), high-density polyethylene (HDPE), polyphenylene sulfide (PPS) and polypropylene (PP).

[0024] It should be noted that PETG, PCT, PCTG or PCTA may be preferred due to increased indentation resistance and optimal delamination resistance.

[0025] Preferably, the polymer, semi-crystalline polymer or crystalline polymer used in the first aspect is a polypropylene polymer. Polypropylene can be a homopolymer or a heteropolymer in this article, and its main component is polypropylene. For example, the semi-crystalline polymer can be a polypropylene copolymerized with ethylene, such as a polypropylene copolymerized with 15wt% or less of ethylene. In a specific example, polypropylene is copolymerized with 3wt% or about 3wt% of ethylene. Copolymerization with ethylene can lead to smoother material processing, such as smoother extrusion. In addition, copolymers, such as copolymers with ethylene, can affect the amount or speed of crystallization. With a higher crystallization rate, the heating capacity required in the production of the desired crystallization can be reduced. This is especially true when the ethylene content in the polypropylene copolymer is low, such as less than 15wt%, less than 10wt% or even less than 5wt%. Preferably, PP can be blended with co[poly(butylene terephthalate-paraoxybenzoate)] copolyester, such as a copolyester content of 5wt%-15wt%, to produce an ethylene-propylene copolymer of interest. As an alternative, PP can be blended with an amorphous polymer or copolymer, such as a cyclic olefin polymer or copolymer (COP or COC). Using an amorphous polymer or copolymer in a blend with PP can result in better melt flow (e.g., in an extruder), and / or enhanced thermal stability of the substrate.

[0026] Preferably, the polymer, semi-crystalline polymer or crystalline polymer used in the first aspect is a heteropolymer, preferably comprising ethylene and propylene. The polymer may for example be a polyethylene copolymerized with polypropylene, for example with 15 wt% or less propylene. According to another example, the semi-crystalline or crystalline polymer is a propylene-ethylene random copolymer (PP-R).

[0027] Preferably, the substrate comprises a filled synthetic material, wherein the filled synthetic material is formed at least from the semi-crystalline or crystalline polymer and a filler material. For the filling material, mainly three variants are envisaged.

[0028] According to a first variant, the filler material has a density of 300 kg / m 3 or lower, for example, 120-180kg / m 3of density, and / or comprises a material selected from the list consisting of rice husks, cork, bamboo, sugar cane, foamed synthetic materials, porous inorganic materials, perlite (preferably expanded perlite), vermiculite (preferably expanded or exfoliated vermiculite), cenolite and pumice. Such a filling material can limit the density of the substrate material obtained. Preferably, the filling material is present in the form of particles. According to a variant, the filling filler, such as bamboo and sugar cane, can be present in the form of fibers. In this case, the fibers can mechanically reinforce the semi-crystalline or crystalline material. Preferably, the weight reduction is at least 10%, or even at least 35%. A weight reduction of 50% or more is not excluded. In the first variant, the amount of filling material available in the filled synthetic material is preferably 5%-25%, expressed as the weight ratio of filler to synthetic material. For example, in a filled polypropylene substrate, 15% of 150 kg / m 3 Filler, for example 15% exfoliated vermiculite. From the possible few additives, and the density of polypropylene is 920 kg / m 3 , which means that about 48% of the volume of the filled synthetic material is made up of the filler and the total density is 550 kg / m 3 . A weight reduction of 370 / 920 or about 40% is achieved here. In view of the weight reduction that can be achieved, the use of lightweight filling materials is also of interest for decorative panels other than the decorative panel of the first independent aspect and thus constitutes a specific independent aspect of the present invention in itself, which is a decorative panel comprising a substrate and a top layer arranged thereon, wherein the substrate comprises at least a filled synthetic material, wherein the filled synthetic material is formed at least from a preferably thermoplastic polymer and a filling material, characterised in that the filling material comprises a polyester having a density of 300 kg / m 3 or lower, e.g. 120-180kg / m 3 of filling materials, and / or materials selected from the list consisting of rice husks, cork, bamboo, sugar cane, foamed synthetic materials, porous inorganic materials, perlite, vermiculite, senoite and pumice. It is obvious that the preferred embodiment of this specific independent aspect can show the characteristics of the preferred mode of the first aspect, and the polymer is not necessarily a crystalline or semi-crystalline polymer. For example, the polymer can also be polyvinyl chloride (PVC). According to a preferred embodiment, all or at least 75vol% or at least 85vol% of the filling materials in the filled synthetic material of the specific independent aspect are lightweight filling materials.

[0029] According to a second variant, the filler material has a density higher than that of the polymer, or 1200 kg / m 3 Or higher density, for example, 1800-3000kg / m 3density, and / or the filler comprises a material selected from the group consisting of chalk, talc, limestone, CaCO 3 , sand and SiO 2 It should be noted that, as mentioned above, the high weight filling material has a further stabilizing effect on possible dimensional instabilities and can make it easier to hold the decorative panel in its installed position. In the second variant, it is preferred that the amount of filling material available in the filled synthetic material is 100%-450% expressed as a weight ratio of filler to synthetic material. For example, in a filled polypropylene substrate, 400% of 2500 kg / m 3 Filler, such as 400% chalk. From the possible few additives, and polypropylene with 920kg / m 3 This means that about 60% of the volume of the filled synthetic material is formed by the filler and the total density is 2045 kg / m 3 It is worth noting that this highly filled polypropylene material weighs less than similarly filled polyvinyl chloride materials and may therefore help limit shipping costs and improve ergonomics for installers. This may also be the case for highly filled polyethylene such as highly filled LDPE or HDPE.

[0030] Care should be taken to use low-weight or high-weight fillers (e.g., density below 250 kg / m 3 Or higher than 2000kg / m 3 It is possible to replace high volumes of semi-crystalline or crystalline polymers, such as PP (possibly copolymers thereof), in synthetic materials with fillers (e.g., more than 20 vol% or more than 40 vol%) without necessarily causing strength problems. This is especially true in the case of the aforementioned second and / or third possible properties of the present invention. Relatively high crystallinity and / or orientation of the polymer in at least one direction are advantageous in this context. In addition, high volume contents of fillers can limit dimensional instability.

[0031] In the first and second variants, according to preferred embodiments thereof, all or at least 75 vol% or at least 85 vol% of the filling material in the filled composite material is a light weight filling material, respectively a high weight filling material.

[0032] According to a third variant, the filler material comprises a portion of low weight filler material as described in the first variant and a portion of high weight filler material as described in the second variant. Preferably, the density of this filler material is within 25% of the density of the semi-crystalline or crystalline polymer, preferably within 20% of the density of the semi-crystalline or crystalline polymer. For example, a density of 920 kg / m 3 Polypropylene can contain a density of 690kg / m 3 -1150 kg / m3 , preferably 736kg / m 3 -1104 kg / m 3 For example, this filler material may have a density of 33.3 vol% or one third of 2500 kg / m 3 of filler material, such as chalk, and 66.6 vol% or two-thirds of the density of 150 kg / m 3 Filling material, such as exfoliated vermiculite. The total density of this filling material is 933kg / m 3 , of which 89.3 wt % consists of high weight filler, in this case chalk.

[0033] In said third variant, it is preferred that the amount of filler material available in said filled synthetic material is 50% to 250%, or preferably 80% to 200%, expressed as a weight ratio of filler to synthetic material. It is preferred that the density of said filled semi-crystalline or crystalline polymer is within 30% or 20% of the density of the envisaged polymer. 3 In the case of polypropylene, the density of the filled polypropylene material is preferably 644-1196 kg / m 3 , or 736-1104kg / m 3 .

[0034] As an example of the third variation, in a filled polypropylene substrate, the above 933 kg / m 3 Filling material. Extracted from a possible few additives, and the density of polypropylene is 920kg / m 3 , which means that about 60% of the volume of the filled synthetic material is constituted by the filler, and 928 kg / m 3 of total density. It is noteworthy that the weight of this highly filled polypropylene material is approximately the same as that of the unfilled polypropylene material, while still achieving acceptable mechanical strength. In this case, the material savings of this polymer material do not have a negative impact on ergonomics and transportation costs. It is obvious that in the case of this filled polyethylene (such as filled LDPE or HDPE), it is also possible to obtain a highly filled synthetic material with a density approximately the same as the polymer contained in the filled synthetic material, for example within 30% or 20% of the density of the polymer involved.

[0035] It is obvious that in the case of the above-mentioned specific independent aspects, preferred embodiments similar to the third variant are possible, therefore whether a semi-crystalline or crystalline polymer is applied. This preferred embodiment is a decorative panel comprising a substrate and a top layer arranged thereon, wherein the substrate comprises at least a filled synthetic material, wherein the filled synthetic material consists of at least a preferably thermoplastic polymer and a filling material, characterized in that the filling material comprises at least a first part and a second part of the filling material, preferably consisting thereof, wherein the first part is a material having a density of 300 kg / m 3 or lower, e.g. 120-180kg / m 3 and / or comprises a material selected from the list consisting of rice husk, cork, bamboo, sugar cane, foamed synthetic material, porous inorganic material, perlite, vermiculite, senoite and pumice, and wherein the second part is a material having a density of 1200 kg / m 3 or higher, for example, density of 1800-3000kg / m 3 The filler material may include a filler selected from the group consisting of chalk, talc, limestone, CaCO 3 , sand and SiO 2 Preferably, the density of such filler material is within 25% of the density of the polymer, and preferably within 20% of the density of the polymer. As mentioned above, the first part and the second part preferably constitute the entire filler material available in the filled synthetic material. Preferably, the amount of filler material available in the filled synthetic material is 50%-250%, or preferably 80%-200%, expressed as a weight ratio of filler to synthetic material. Preferably, the amount of filler material available in the filled synthetic material is 50%-250%, or preferably 80%-200%, expressed as a weight ratio of filler to synthetic material. Preferably, the density of the filled synthetic material is within 30%, or within 20%, of the assumed polymer density. Preferably, the second part of the filler material, i.e. the high density part, is present in the filled synthetic material at a higher weight percentage than the first part, and preferably, the second part of the filler material is present in the filled synthetic material at a lower volume percentage than the first part. Preferably, the weight percentage difference between the second part and the first part is at least 20wt% or at least 25wt%. Preferably the volume percentage difference between the second portion and the first portion is at least 5 vol%, or at least 10 vol%.

[0036] Preferably, in the case of filled synthetic materials, the polymer and / or the filling material, whether in accordance with the first, second or third variant, is provided with a coupling agent and / or maleic anhydride and / or a silane, such as an aminosilane. The use of maleic anhydride, silane or coupling agent enhances the incorporation of the filling material into the polymer.

[0037] It should be noted that alternatives to the fillers listed in the first through third variations include wollastonite, mica, and thermomechanical pulp fibers.

[0038] In addition to the filling material, the substrate or the filled synthetic material (as the case may be) may also include additives, such as one or more elastomers. Preferably, 15-200 phr (per hundred weight parts of resin, i.e., the fraction of the semi-crystalline or crystalline polymer) of the elastomer is used. The use of an elastomer allows the required flexibility to be set for the panel. The flexural modulus of the preferred substrate is 550 MPa or less, and even better is 275 MPa or less. As an elastomer, styrene-ethylene / butylene-styrene triblock copolymer (SEBS) can be used. This elastomer is particularly effective when the semi-crystalline polymer is a propylene-ethylene random copolymer (PP-R).

[0039] Preferably, in the matrix, or in the filled synthetic material (as the case may be), the semi-crystalline or crystalline polymer is a mixture of a semi-crystalline or crystalline homopolymer such as polypropylene or polyethylene and a semi-crystalline or crystalline heteropolymer. Preferably, the heteropolymer is constructed at least by the monomers of the homopolymer. Preferably, the heteropolymer is constructed at least 30wt% or at least 50wt% by the monomers of the homopolymer. For example, in the case where the homopolymer is polypropylene, respectively polyethylene, the heteropolymer can be constructed at least by propylene, respectively ethylene, such as with a heteropolymer comprising ethylene and propylene, such as the case of propylene-ethylene random copolymer (PP-R). In a specific embodiment, the semi-crystalline or crystalline polymer is a mixture of a polypropylene homopolymer and an ethylene-propylene heteropolymer containing at least 50% ethylene, such as an ethylene-propylene-diene copolymer. In the mixture of homopolymers and heteropolymers of the preferred embodiment, the homopolymer preferably constitutes 25mol%-45mol%, even better 30mol%-40mol%.

[0040] According to a specific embodiment, the semi-crystalline polymer is foamed. Preferably, the foaming results in a weight reduction of 10% or more. Preferably, the foam is a closed-cell foam, i.e. a foam in which the cells are mainly closed cavities. As a foaming agent, for example, citric acid and / or sodium bicarbonate can be used. An ideal semi-crystalline polymer for foaming is polypropylene / polypropylene grafted glycidyl methacrylate / thermoplastic polyester elastomer (PP / PP-g-GMA / TPEE).

[0041] According to a most preferred embodiment of the first independent aspect of the present invention, the substrate is a filled synthetic material comprising

[0042] -30 vol% to 65 vol% of semi-crystalline polymer;

[0043] - preferably 3 vol% or more of elastomer;

[0044] -30 vol% to 65 vol% or more of filler material; and

[0045] - 5 vol% or less of additives other than elastomers and filler materials.

[0046] For the semi-crystalline polymer, homopolymers and / or heteropolymers of ethylene and / or propylene are preferably used. For example, the semi-crystalline polymer may be a mixture of essentially polypropylene with an ethylene-propylene copolymer or an ethylene-propylene-diene copolymer, or essentially a mixture of polyethylene with an ethylene-acrylic acid copolymer or an ethylene-propylene-diene copolymer, or essentially a mixture of polypropylene with COC or COP. The filling material may be selected according to the first, second or third variant described above.

[0047] According to a second independent aspect, the present invention is a method for manufacturing a decorative panel, wherein the panel comprises a substrate and a top layer arranged thereon, wherein the substrate comprises at least a semi-crystalline polymer or a polymer selected from the list consisting of polyacetal (POM), polyphenylene sulfide (PPS), polyamide (such as PA6 and PA 66), polyethylene terephthalate (PET), glycol-modified polyethylene terephthalate (PETG), polycyclohexane dimethyl terephthalate (PCT), glycol-modified polycyclohexane dimethyl terephthalate (PCTG), polycyclohexanedimethylene terephthalate (PCTA), polyethylene (PE), low-density polyethylene (LDPE), high-density polyethylene (HDPE), polybutylene terephthalate (PBT) and polypropylene (PP), wherein the method comprises the following steps: the substrate is at least partially provided by an extrusion operation in which the polymer is extruded through a die, preferably characterized in that the method further comprises one or a combination of two or more of the following steps.

[0048] According to a first possible step, the method comprises a step of cooling the extruded semi-crystalline polymer, for example in a bath, preferably a water bath. The water in the bath may be maintained at a temperature above the glass transition temperature of the polymer, but preferably below the melting temperature of the corresponding polymer. Preferably, the water is maintained at a temperature of 25-60° C. Cooling by means of a water bath makes it possible to freeze the crystallinity and / or orientation obtained in the polymer. Preferably, the cooling step is carried out upstream of any embossing operation providing a structure to the top layer of the decorative panel. In this case, the embossing can be performed more precisely, for example corresponding to the decoration contained in the top layer. According to a variant or in combination with the bath, the extruded semi-crystalline polymer can be cooled using a nozzle or a liquid curtain, preferably using water and / or a gas such as cooling air.

[0049] According to a second possible step, the method comprises a step of actively drawing the extruded semi-crystalline polymer from the die. By actively drawing the semi-crystalline polymer, for example polypropylene, potentially an ethylene-polypropylene copolymer as described above, a more defined orientation of the polymer in the extrusion direction can be obtained. The active drawing can be obtained by pulling the extruded material in the nip of a pair of driven rollers or by a driven belt.

[0050] According to a third possible step, the method comprises a step of adhering a polymer film (preferably a uniaxially or biaxially oriented polymer film) to the extruded semi-crystalline polymer. The adhesion is preferably, for example, by thermal lamination of one or more rollers. Adhering an oriented film, such as an oriented polypropylene film, can stabilize the decorative panel. Preferably, such a film is applied to both sides of the extruded polymer material. Alternatively, instead of adhering a polymer film, a layer, such as a polypropylene layer, can be cast directly or indirectly on the substrate containing the extruded polymer material. More generally, preferably at least one polymer film or layer, whether oriented or not, is thermally laminated or cast on one or both sides of the extruded polymer material. In the case where such a layer or film is provided on both flat sides, a decorative panel with a more stable, balanced, sandwich structure can be obtained. If this third possible step is combined with the above-mentioned first possible step, the step of adhering the film is preferably carried out downstream of the cooling, for example, downstream of the bath. In this case, the substrate material is more stable and the film can be adhered more accurately. According to a variant, the step of adhering the film occurs upstream of the cooling, for example, upstream of the bath or upstream of contact with the cooling roller. In the latter case, the available heat of the extruded polymer material can be used to adhere the film, while the cooling can freeze the crystallinity of the substrate material and / or top layer. It is obvious that the film or layer can be the film or layer on which the decorative print is or is to be provided. Alternatively, the film or layer can be or form part of a transparent or translucent wear layer applied to the decorative print or decorative print foil.

[0051] According to a fourth possible step, the method comprises a step of heat treating the surface of the extruded semi-crystalline polymer, preferably by means of rollers and / or plates, wherein the rollers and / or plates are preferably cooled. According to a variant, or in combination therewith, one or more rollers and / or plates may be heated. Preferably, the rollers and / or plates are in direct contact with the surface of the extruded semi-crystalline polymer. The step of heat treating the extruded material enables the crystallinity and / or orientation to be set to the desired level. The heat treatment step may also be used to anneal possible stresses. Preferably, the heat treatment step takes place between the die and a possible subsequent lamination operation, wherein, for example, the top layer or part thereof is laminated onto the extruded semi-crystalline material, and / or between the lamination operation and a possible embossing operation providing structure to the top layer of the decorative panel.

[0052] According to a fifth possible step, the method comprises a step of cooling and subsequently heat treating the extruded semi-crystalline polymer, whether forced or not, or vice versa. The combination of cooling and subsequent heating can lead to freezing of crystallinity and / or orientation, while subsequent heating can lead to induced stress annealing and produce a shrinkage effect. Such a heat treatment can avoid excessive shrinkage after manufacturing and / or installation. It is obvious that heating and / or cooling can be achieved in many different ways, such as by using a water bath or a nozzle, as described in the first possible step, or by using rollers and / or plates, as described in the fourth possible step.

[0053] According to the sixth possible step, the method includes the step of controlling the crystallinity of the semi-crystalline polymer extruded. The crystallinity is preferably controlled by measuring the crystallinity of the semi-crystalline material extruded online or offline, and changing at least one of the extrusion speed, extrusion temperature, temperature of heat treatment or cold treatment (such as the water temperature in the bath of the first possible step) and / or the temperature of the roller and / or plate (such as described in conjunction with the fourth possible step). For the online measurement of crystallinity, an optical method can be used. For example, the semi-crystalline material extruded can be irradiated with a light beam, the scattered light is collected, the collected scattered light is converted into a Raman spectrum, and the crystallinity is determined using the Raman spectrum. For example, the method described in WO 1999 / 027350 can be used. The result can be used, for example, to automatically adjust the extrusion speed, extrusion temperature and / or the temperature of heat treatment or cold treatment in a feedback loop.

[0054] According to a seventh possible step, the method comprises a step of dividing the extruded semi-crystalline polymer into panels having dimensions corresponding or substantially corresponding to the dimensions of the panel finally obtained. For example, the panels may be rectangular and oblong. According to a particular embodiment, the longitudinal direction of the panels is formed perpendicular to the extrusion direction. In this case, potential shrinkage or other dimensional instabilities caused by the orientation of the semi-crystalline polymer in the extrusion direction are in the transverse direction of the panels and can therefore be limited to absolute dimensions.

[0055] According to an eighth possible step, the method comprises a step of drying the polymer to be extruded and / or drying the filler material to be incorporated into said polymer before mixing said polymer and said filler material. These drying steps are particularly important when said polymer is PET, PETG, PCT, PCTG or PCTA. These polymers are susceptible to hydrolysis.

[0056] According to a ninth possible step, the method comprises, for example, a step of feeding a certain amount of filler material directly into the extruder barrel via one or more inlets downstream of the main extruder inlet. Preferably, the main filler amount (i.e. more than 50%), all or almost all of the filler amount, is added to the material to be extruded via the one or more inlets downstream of the main extruder inlet. Thus, only a small portion of the filler material is added to the polymer or not at all before extrusion and / or passing through the main extruder inlet. At the main extruder inlet, the polymer (possibly containing additives) can be added to the barrel in the form of pellets, flakes or needles.

[0057] It is preferred to apply a deep vacuum, e.g., a pressure below 5 mbar, or even below 2 mbar, in the extruder used in the extrusion operation in order to remove any residual water or other contaminants in the extruder section. A low vacuum is particularly important when the polymer is PET, PETG, PCT, PCTG or PCTA.

[0058] Preferably, a parallel or conical co-rotating twin-screw extruder is used in the extrusion operation. The use of a single screw extruder or a multi-screw rotating extruder is not excluded.

[0059] According to still other possible steps, the method comprises:

[0060] - a step of forming an outermost layer of the substrate, wherein the outermost layer comprises an elastomer, preferably the outermost layer is co-extruded with the polymer, for example through the same die;

[0061] - a step of applying an adhesive layer, a heat seal additive, ethylene vinyl acetate or ethylene methyl acrylate to the outermost surface of the substrate; and / or

[0062] - A step of corona or plasma treating the outermost surface of said substrate.

[0063] It is obvious that the method of the second aspect is preferably applied to manufacture a panel according to the first aspect of the present invention and / or its preferred embodiments.

[0064] In general, it is worth noting that wherever crystallinity values ​​are described herein, the crystallinity is preferably measured according to ISO 11357-3:2018 using differential scanning calorimetry (DSC) and / or at a heating rate of 20°C / min. Using DSC, the residual enthalpy of crystallization to reach 100% crystallinity in a sample can be measured. The residual enthalpy is compared to the full crystallization enthalpy when starting from an amorphous sample of the same polymer, thereby calculating the percentage of additional crystallization that occurs during DSC. It is apparent that the half-crystallinity present in the sample before the start of DSC can be expressed as 100% minus the percentage of additional crystallization obtained.

[0065] It is further evident that where a semi-crystalline polymer is mentioned in the first and second aspects of the invention, the polymer may be or instead be a polymer selected from the list consisting of polyacetal (POM), polyphenylene sulfide (PPS), polyamide (such as PA6 and PA66), polyethylene terephthalate (PET), polyethylene (PE), low density polyethylene (LDPE), high density polyethylene (HDPE), polybutylene terephthalate (PBT) and polypropylene (PP). According to the invention, such a polymer need not necessarily be semi-crystalline, but may be crystalline, or substantially amorphous, for example.

[0066] According to the most preferred embodiment, the polymer or semi-crystalline polymer is a mixture of polypropylene and ethylene-propylene copolymer or ethylene-propylene-diene copolymer, or a mixture of polypropylene and an amorphous polymer or copolymer such as COC or COP.

[0067] According to the present invention, the substrate may be a single layer or comprise a plurality of substrate layers, preferably an odd number of substrate layers. The substrate, whether single layer or multilayer, preferably constitutes at least half the thickness and / or half the weight of the decorative panel, and / or can be used at least in the central position within the thickness of the decorative panel.

[0068] The decorative panel of the present invention preferably has a total thickness of 2-8 mm, and more preferably 3.2-5.5 mm. The substrate, whether multi-layer or single-layer, preferably has a thickness of 2-5 mm.

[0069] It is clear that in the context of the present invention, any panel portion represented as a layer, for example, a substrate layer, has properties that are significantly different from adjacent layers. Such different properties may include, for example, different material composition, different color, different geometry.

[0070] As described in any aspect, the top layer may include a decoration, preferably a printed decoration. The top layer may also include a transparent or translucent layer applied to the top of the printed decoration. According to a first possibility, the printed decoration is applied to a polymer foil such as a polypropylene foil or a polyethylene foil. In this case, the wear layer may also include a polypropylene foil or a polyethylene foil, and a possible surface varnish layer, for example, a UV and / or excimer cured varnish layer, such as a polyurethane varnish layer. According to a second possibility, the printed decoration is applied by forming it on a semi-crystalline material, and may also have an intermediate layer of one or more primer layers and / or background layers. In this case, the wear layer may be formed as a UV and / or excimer cured varnish layer applied as a liquid, for example, an acrylic varnish layer. According to a specific embodiment, the top layer includes one or more casting layers, for example, a polypropylene casting layer. This casting layer may form a primer and / or background layer for the printed object formed on the substrate, and / or may form a part of a transparent or translucent wear layer on the top of the printed decoration.

[0071] The decoration of the top layer preferably comprises a wood pattern. In this case, the wood pattern preferably has a grain direction corresponding to the direction of one edge of the panel and / or to the direction of the potential orientation direction of the polymer of the substrate. In the case of rectangular and oblong panels, it preferably corresponds to the direction of the longitudinal edges.

[0072] The decorative panel of any of the above aspects may be provided with connecting parts on at least two opposing edges, allowing two such panels at the respective edges to be connected to each other, wherein, in the connected state, locking is obtained in a vertical direction perpendicular to the plane of the connected panels and in a horizontal direction perpendicular to the edges in the plane of the connected panels. Preferably, the connecting parts are substantially formed as tongues and grooves with locking means. For example, such connecting parts are as described in WO 97 / 47834. The connecting parts and the locking means preferably have one or more of the following properties:

[0073] - said connecting means and locking means are integrally formed with the material of said decorative panel and preferably form at least 70% of the contour of the respective edge on said substrate comprising said semi-crystalline polymer material and / or said filled synthetic material, as seen in a cross section in a plane perpendicular to said edge;

[0074] - the groove has a lower groove lip and an upper groove lip, wherein the lower groove lip preferably extends beyond the upper groove lip. Preferably, the locking means comprises a protrusion formed on the upper side of the lower groove lip and an excavation at the bottom of the tongue;

[0075] - the lower side of the upper tongue-and-groove lip and / or the upper side of the lower tongue-and-groove lip is completely formed in the substrate comprising the semi-crystalline polymer material and / or the filled synthetic material. The lower side of the upper tongue-and-groove lip and / or the upper side of the lower tongue-and-groove lip is preferably completely formed of the semi-crystalline material and / or the filled synthetic material;

[0076] - the substrate is an extruded semi-crystalline polymer, wherein the horizontal direction coincides with the extrusion direction, wherein the panel is rectangular and oblong, and the connecting means are preferably applicable at the pair of longitudinal edges. Alternatively, the connecting means may be applicable at a pair of short edges and / or at both pairs of edges.

[0077] In general, the inventors have noticed that a decorative panel having a top layer applied to a substrate comprising a semi-crystalline or crystalline polymer and / or a polymer selected from the list consisting of polyacetal (also known as polyoxymethylene (POM)), polyphenylene sulfide (PPS), polyamide (such as PA6 and PA 66), polyethylene terephthalate (PET), glycol-modified PET (PETG), polycyclohexane dimethyl terephthalate (PCT), glycol-modified polycyclohexane dimethyl terephthalate (PCTG), polycyclohexanedimethylene terephthalate (PCTA), polyethylene (PE), low-density polyethylene (LDPE) (e.g., linear low-density polyethylene (LLDPE)), high-density polyethylene (HDPE), polybutylene terephthalate (PBT), polylactic acid (PLA), polyetheretherketone (PEEK) and polypropylene (PP) may be prone to top layer delamination problems. The inventors believe that this may be due to the effect of tension differences in the top layer and the substrate when cooling after hot lamination.

[0078] Such decorative panels may in particular be subject to differential tensions according to a second possible property, namely a degree of crystallinity of the polymer higher than 35%, preferably higher than 50%, preferably measured using differential scanning calorimetry (DSC) according to ISO 11357-3:2018. The degree of crystallinity may be, for example, about 60%. Cooling of a polymer with such a high degree of crystallinity may lead to higher differences in tension between the layers (e.g. between the substrate and the decorative top layer), so that the adhesion may partially fail.

[0079] Independent of its crystallinity, the surface energy of the polymer, for example the surface energy of polypropylene (PP), may play an important role. For example, the surface energy of polypropylene is too low to make good bonding difficult to achieve.

[0080] A variety of measures can be taken to improve the lamination strength of the top layer and the substrate. Preferably, one or more of the following possible measures are adopted.

[0081] According to a first possible measure, an elastomer is used as an additive in the polymer, for example, 0.1-7.5 phr. For example, thermoplastic polyolefin (TPO) is used as an elastomer. Practical examples of elastomers that can be used according to the first possible measure include:

[0082] - thermoplastic polyolefins obtained by the Cataloy process or by any multistage gas phase polymerization process, for example homo- or hetero-polypropylene;

[0083] - block copolymers such as polypropylene;

[0084] - styrene block copolymers;

[0085] - A polymer or copolymer comprising or consisting of ethylene-propylene-diene-monomer (EPDM), styrene-ethylene-butadiene-styrene (SEBS), poly(styrene-butadiene-ethylene) (SBS), polyether block amide (PEBA), thermoplastic polyurethane (TPU), styrene-ethylene-propylene-styrene (SEPS), styrene-ethylene-ethylene-propylene-styrene (SEEPS), acrylonitrile-ethylene-styrene (AES) or polybutadiene (PB).

[0086] According to a second possible measure, one or both outermost layers of the substrate or of the extruded sheet contained in the substrate comprise an elastomer or consist of an elastomer. Preferably, the elastomers mentioned in the first measure are used. This outermost layer can be coextruded with the remainder of the extruded sheet contained in the substrate or forming the substrate. Preferably, this outermost layer forms less than 10% of the thickness of the substrate. This second possible measure will produce similar results from the point of view of adhesion to the top layer, but with less impact on the mechanical properties of the substrate or the extruded sheet as a whole, such as flexibility. When this outermost layer is applied to the surface of the substrate opposite to the top layer, for example, a higher adhesion can be obtained during installation with the underground or with a sound insulation layer applied during production.

[0087] According to the first as well as the second possible measure, the temperature required to obtain good adhesion during the hot lamination of the top layer can be reduced. This is also advantageous in view of the lamination of a top layer which has been provided with an embossing before the hot lamination. For example, such a top layer can comprise a printed foil and a transparent wear layer comprising polypropylene cast thereon and embossed. The risk that such an embossing will be reduced or even disappear during the hot lamination is minimized.

[0088] According to a third possible measure, the substrate or one or both outermost layers of the extruded sheet contained in the substrate comprises a tie layer or a heat-seal additive, for example, maleic anhydride grafted polypropylene or polyethylene-based adhesive, polyethylene-based adhesive, or consists thereof. Heat-seal additives themselves are well known in the food packaging industry for improving the sealing of bags. The inventors have found that these sealing additives can be used to improve the adhesion between the top layer of the decorative panel of the invention and the substrate.

[0089] According to a fourth possible measure, the substrate or one or both outermost layers of the extruded sheet contained in the substrate may include or consist of ethylene vinyl acetate or ethylene methyl acrylate. Ethylene vinyl acetate and / or ethylene methyl acrylate are particularly effective for improving the lamination strength on substrates comprising polypropylene as the polymer (e.g., polypropylene having a crystallinity of 50% or more).

[0090] According to a fifth possible measure, the surface of one or both outermost layers of the substrate may be subjected to a corona or plasma treatment. This treatment is preferably applied when the respective surfaces are above room temperature, for example when these surfaces still have an elevated temperature due to the extrusion process. Preferably, no forced cooling step is applied to the extruded sheet between extrusion and corona or plasma treatment and / or the corona or plasma treatment is started or carried out within the first five or two meters from the die (measured along the trajectory of the extruded sheet).

[0091] According to a sixth possible measure, a cooling operation is carried out on the top layer as soon as possible after hot lamination, for example, starting or carrying out the cooling operation within the first two meters from the die (measured along the trajectory of the extruded sheet). The cooling operation can be carried out by a cooling roller in contact with the top layer. The cooling operation can freeze the crystallinity of the substrate and / or the top layer. In this case, tension differences that lead to adhesion problems can be kept to a minimum.

[0092] It is obvious that the above mentioned extruded sheet is preferably obtained from an extrusion operation, wherein the polymer is extruded through a die preferably having a slot opening. It is further obvious that the sheet obtained has a size that may be larger than the desired size of the decorative panel finally obtained, and therefore, the sheet may need to be formed into a plurality of panels having the final size of the decorative panel, wherein these panels are subsequently further processed and finished to form the decorative panel of the present invention.

[0093] It is obvious that the above possible measures for dealing with delamination and increasing adhesion lead to corresponding preferred embodiments of the first and / or second aspects of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0094] In order to better illustrate the characteristics of the present invention, some preferred embodiments are described below, as examples without any limiting character, with reference to the accompanying drawings, in which:

[0095] Figure 1 A floor panel having the features of the present invention is represented;

[0096] Figure 2 Shown on a larger scale Figure 1 The cross section of line II-II is shown in ;

[0097] Figure 3 express Figure 2 the connection status of the connection device shown;

[0098] Figure 4-6 Shown on a larger scale Figure 1 A cross section of line IV-IV as represented in, but a variant;

[0099] Figure 7 and Figure 8 Similar to Figure 3 The view of shows a variation;

[0100] Fig. 9 Similar to Figure 2 The view of shows a variation;

[0101] Fig.10 Some steps in the method of manufacturing a decorative panel according to the present invention are shown;

[0102] Figure 11-13 by Fig.10 The view of the area indicated by F11 shows a variant. DETAILED DESCRIPTION

[0103] Figure 1 denoted a rectangular floor panel 1. In this case, the floor panel 1 is rectangular and oblong.

[0104] Figure 2 As is clearly shown, the floor panel 1 comprises a substrate 2 and a decorative top layer 3 arranged thereon.

[0105] The substrate 2 comprises a semi-crystalline polymer 4, in this case a filled ethylene-propylene copolymer, and is provided on at least two opposing edges 5-6-7-8, in this case a pair of opposing long edges 5-6 and a pair of opposing short edges 7-8, with mechanical connecting means 9.

[0106] Figure 2It is clearly shown that the connection means 9 on the opposite long edges 5-6 are essentially realized as a tongue 10 and a groove 11 with an upper lip 12 and a lower lip 13. In this case, the lower lip 13 extends in the horizontal direction beyond the distal end 14 of the upper lip 12. The connection means 9 shown at least allow connection by a rotational movement W along the respective edge 5-6.

[0107] Figure 3 It is shown that, in the connected state, locking is obtained in a horizontal direction H1 perpendicular to the connection edges 5-6 and in the plane of the panels 1 and in a vertical direction V1 perpendicular to the plane of the connected panels 1. The connection means 9 consists of a milled profile, at least 70% of the periphery of which is arranged in the substrate 2 and in this case in the filled semi-crystalline polymer 4. In this case, the connection means 9 is practically completely arranged in the filled semi-crystalline polymer 4 of the substrate 2, but a portion 15 of its periphery is formed on the decorative top layer 3.

[0108] Figure 3 At least one pair of horizontal active locking surfaces 16-17 of the connecting device 9 is shown implemented in the semi-crystalline polymer material 4 of the substrate 2. Here, this involves a first pair of locking surfaces 16-17 formed on a protruding locking portion 18 of the lower tenon lip 13 and a locking tenon groove 19 cooperating therewith on the underside of the tongue 10. In this example, a second pair of horizontal active locking surfaces 20-21 is formed on the decorative top layer 3, or on the above-mentioned portion 15 of the periphery of the connecting device 9. Several pairs of vertical active locking surfaces 22-23-25-26 are formed by the filled semi-crystalline polymer 4 of the substrate 2. Here, this involves at least a first pair of vertical active locking surfaces 22-23 on the upper side of the tongue 10 and the lower side of the upper lip 12 of the tenon groove 11, and at least a second pair of vertical active locking surfaces 25-26 on the lower side of the tongue 10 and the upper side of the lower lip 13 in the tenon groove 11. In Figure 3 In the example of, the second pair of vertical active locking surfaces 25-26 are formed so that they extend at least horizontally at a position vertically below the above-mentioned upper tenon lip 12. In this case, the third pair of vertical active locking surfaces 27-28 are also formed near the above-mentioned first horizontal active locking surfaces 16-17.

[0109] Figure 4It is clearly shown that at least one, and in this case even multiple, reinforcement layers 29-30 can be applied to the substrate 2. In this example, the first reinforcement layer 30 extends uninterruptedly in the above-mentioned lower tenon lip 13; the second reinforcement layer 29 extends uninterruptedly in the above-mentioned upper tenon lip 12. The first and second reinforcement layers 29-30 are therefore positioned off-center with respect to the thickness T1 of the substrate 2. On the sides of the reinforcement layers 29-30 facing away from the center of the substrate 2, in this example, the reinforcement layers are each flanked by additional substrate layers 31 of filled semi-crystalline polymers. In this example, these additional substrate layers 31 show a different composition than the central substrate layer 32 of the substrate 2, for example, they contain no filler or less filler than the central substrate layer 32. It should be noted that Figure 4 The example of shows the fifth possible characteristic mentioned in the summary of the invention, wherein the additional substrate layer 31 has an equal thickness and is positioned with one of its main surfaces equidistant from the center line C of the substrate 2. The additional substrate layer 31 is at least away from the central substrate layer 32.

[0110] Obviously, the substrate 2, or at least its central substrate layer 32, is preferably positioned so that it is at least in the center of the substrate 2, i.e. on the center line C. In this case, the thickness T2 of the central substrate layer 32, i.e. the layer between the two reinforcement layers 29-30, is equal to more than 40% of the substrate thickness T1.

[0111] The decorative top layer 3 comprises a printed pattern 33 and represents a single wood board. The printed pattern 33 is provided on a thermoplastic foil 34, i.e. in this case a biaxially oriented polypropylene foil. The floor panel 1 further comprises a translucent or transparent wear layer 35, which is provided above the decorative or printed pattern 33.

[0112] It should be noted that, according to one embodiment not shown, the floor panel 1 according to the invention can exhibit an additional layer on the underside of the substrate 2. Here, this preferably involves a foam layer, for example a foam layer of cross-linked or crosslinked polyethylene (XPE), which is fixed by glue to the underside of the substrate 2, for example specifically to the substrate layer 31 flanked by the reinforcement layer 30. In this case, this involves a soft foam.

[0113] In addition, it should be noted that Figure 3 In the connected state, a tension force can be obtained between the respective floor panels 1 , more specifically at the location of the second pair of horizontal active locking surfaces 20 - 21 , ie between the respective decorative top layers 3 on the upper edges of the connected floor panels 1 . Figure 3The dashed line 36 in WO 97 / 47834 shows that such a tension can be obtained, for example, by the lower lip 13 in the connected state being spring-deflected and in the connected condition pushing against the tongue 10. Such a pre-tension is known, for example, from WO 97 / 47834.

[0114] according to Figure 3 In a variant not shown, in the connected state, there may be a so-called play instead of pretension. In this case, in the connected state, there may be some space between the first pair of horizontal active locking surfaces 16-17, while the second pair of horizontal active locking surfaces contacts at a position above the vertical active contact surfaces 22-23 between the upper side of the tongue 10 and the lower side of the upper lip 12 of the groove 11. Such space preferably extends over a horizontal distance of less than 0.2 mm or less.

[0115] exist Figure 1-3 In the example of FIG. 4 , the same connecting means 9 are applied to the opposite short edges 7 - 8 of the floor panel 1 as to the opposite long edges 5 - 6 .

[0116] In addition to the optional reinforcement layers 29-30 and the optional additional substrate layer 31 shown, Figure 4 An example of a decorative panel according to the invention is given, in which the short edges 7-8 are provided with a connecting device 9 having a male part 37 and a female part 38, which allows two such floor panels 1 to be connected at the respective short edges 7-8 by moving the male part 37 downwards in the female part 38 M, wherein in the connected state, locking in the horizontal direction H1 as well as in the vertical direction V1 is achieved. For example, according to Figure 2 and Figure 3 , the rotatable profiles on the long edges 5-6 are connected, for example, according to Figure 4-6 The combination of downwardly connectable profiles on the short edges 7-8 of any one of the panels results in the formation of a floor panel 1 which can be connected by a so-called folding-down movement. Here, the long edges 5-6 are provided with each other by a rotational movement W, wherein a downward movement M is generated by this rotational movement W at the short edges 7-8, which provides a male part 37 present in a female part 38.

[0117] The example of such a downwardly connectable profile shown here is made in one piece with the substrate 2 of the floor panel 1 and comprises a cooperating hook 39 and an undercut 40 for achieving locking, as well as a hook-shaped part 41 on the lower lip 13, which in this case also shows an undercut 42. The undercut 42 on the hook-shaped part 41 is made to form an angle A1 of 1° to 10° (preferably about 5°) with the vertical direction. The locking groove 19 cooperating with the above-mentioned hook-shaped part 41 is completely located below the reinforcement layer 29 at the upper surface.

[0118] In this case, the above-mentioned cooperating hooks 39 and undercuts 40 comprise vertical active contact surfaces 22-23 that, in the connected state, cooperate in the filled semi-crystalline polymer 4 of the substrate 2. The horizontal and vertical active contact surfaces 16-17 of the hook-shaped component 41 are also completely realized in the filled semi-crystalline polymer 4 of the substrate 2.

[0119] The upper surface of the lower lip 13 consists entirely of the filled semi-crystalline polymer 4 of the base material 2. In the connected state, the edge profile also shows the vertical active contact surfaces 25-26 formed on this upper surface. There is a space 43 between these vertical active contact surfaces 25-26 and the horizontal active contact surfaces 16-17. The uppermost reinforcement layer 29 extends integrally on the above-mentioned locking groove 19 at the lower side of the male connection part 37.

[0120] On the lower side of the lower tenon lip 13, a recess 44 is formed, which at least partially extends below the above-mentioned space 43. This provides a smoother connection, even if there is an overlap 45 in the profiles of the male connection part 37 and the female connection part 18 at the location of the horizontal active locking surface 16-17. The lowermost reinforcement layer 30 is removed at the location of the above-mentioned recess 44. This does not necessarily have to be the case. According to an embodiment not shown, the lowermost reinforcement layer 30 can extend integrally above the recess 44.

[0121] Figure 5 A profile variant that can be connected to each other by a downward shift M is shown, in which the hook 39 is located at the distal end 46 of the lower lip 13 of the female part 38, and the undercut 40 is provided in the male part 38. Here, too, the upper surface of the lower lip 13 is completely formed by the filled semi-crystalline polymer 4 of the substrate 2, and in the joined state, the edge profile shows the vertical active contact surfaces 25-26 formed on this upper surface. There is a space 43 between these vertical active contact surfaces and the horizontal active contact surfaces 16-17. The lowermost reinforcement layer 30 extends integrally in the lower lip 13, while the uppermost reinforcement layer 29 extends integrally on the above-mentioned locking groove 19 on the lower side of the male connection part 37.

[0122] exist Figure 5 In the example of , the hook-shaped part 41 also has an undercut 42, wherein the undercut 42 is realized at an angle A1 of 1° to 10° (preferably about 5°) to the vertical direction. Figure 4 and Figure 5 In the embodiment, such an undercut 42 at the position of the horizontal active contact surface 16-17 on the hook-shaped part 41 is not necessary, and a vertical contact surface or a contact surface with a smaller inclination than vertical can also be used, for example, the corresponding contact surface is inclined at an angle of 45° to 90° to the horizontal plane.

[0123] Figure 6 A variant of the downwardly connectable profile is shown, in which the hook 39 is formed by a separate insert 46, which in this case is arranged in the male part 37. Such a separate insert 46 is preferably formed from a thermoplastic material, for example at least from PP, PVC or ABS (acrylonitrile-butadiene-styrene), and in the connected state preferably exhibits (such as here) a vertical active contact surface 22 with the filled semi-crystalline polymer 4 of the female part 38. In this way, an exact vertical positioning of the male part 37 in the female part 38 can be obtained. In this example, the above-mentioned separate insert 46 is located in a seat 47 with walls, which are completely formed by the filled semi-crystalline polymer 4 of the substrate 2.

[0124] Obviously, in Figures 4 to 6 In the example of FIG. 4 , the hook-shaped portion 41 , the locking groove 19 cooperating therewith on the lower side of the male part 37 , each time extends upwardly into the upper half of the base material 2 , thereby extending above the center line C.

[0125] Figure 7 Another variation is shown in which the connecting means 9, for example the connecting means 9 of the opposing long edges 5-6, exhibits some preferred features, each of which alone or in any combination provides an edge profile that is ideally suited for application to floor panels 1 employing a substrate 2 of a filled semi-crystalline polymer 4, such as a filled ethylene-propylene copolymer. This is associated with the following features:

[0126] - the vertical positive locking surfaces 25-26 between the lower side of the tongue 10 and the upper side of the lower lip 13 are located substantially or even completely in this case on the projection 48 of the lower lip 13, i.e. on the part of the lower lip 13 that extends beyond the distal end of the upper lip 12. Preferably, in the connected state, a space 49 is located between the lower side of the tongue 10 and the upper side of the lower lip 13, wherein the space 49, for example here, extends horizontally below the tongue 10, at least from the tip 50 of the tongue 10 upwards to beyond the distal end of the upper lip 12. In this way, the risk of breaking of the tongue 10 when turning it into the groove 11 is minimized, while still obtaining a sufficient vertical locking; and / or

[0127] - the projection of the vertical active contact surface 25-26 between the lower side of the tongue 10 and the upper side of the lower lip 13 in a horizontal plane shows a length L1 which is at least 15%, and better still at least 20% or 25%, of the length L2 of the protrusion 48 of the lower lip 13; and / or

[0128] - the length L2 of the protrusion 48 of the lower lip 13 is at least 80% of the thickness T1 of the substrate layer comprising the filled semi-crystalline polymer 4 and preferably less than 130% of its thickness T1; and / or

[0129] - The minimum width B1 of the upright portion 18 of the lower lip 13 at the location of the horizontal active locking surface 16-17 is at least 15% of the thickness T1 of the substrate layer containing the filled semi-crystalline polymer 4, and better at least 20% of the thickness T1 of the substrate layer containing the filled semi-crystalline polymer 5.

[0130] Figure 8 Another variant is shown in which the connecting means 9, for example the connecting means of the opposing long edges 5-6, exhibits some preferred features, each of which alone or in any combination produces an edge profile that is well suited for application to floor panels 1 having a substrate 2 of a semi-crystalline polymer 4 (whether filled or not, such as a filled ethylene-propylene copolymer). This particularly relates to the combination of Figure 7 The features mentioned, as well as the following features, however, do not necessarily have to be Figure 7 Application of feature combination in:

[0131] - the lower lip 13 shows a point 51 or a region where the residual thickness D1 of the lower lip 13 is smallest, wherein the floor panel 1 comprises a reinforcing layer 30 extending in the respective lower lip 13, and wherein the reinforcing layer 30 is offset from the center of the residual thickness D1 at the location of the point 51 or region, preferably closer to the upper side than to the lower side of the lower lip 13, as shown here by the arrow E1. In this way, a very significant influence is exerted on the possible bending of the lower lip 13; and / or

[0132] - the upper lip 12 shows, at the location of the perpendicular active locking surfaces 22-23, a point or area 52, wherein the residual thickness D2 of the upper lip 12 is minimal, wherein the floor panel 1 comprises a reinforcing layer 29 extending in the respective upper lip 12, and wherein said reinforcing layer 29 is offset from the center of said residual thickness D2 at the location of said point or area 53, preferably closer to the lower side than to the upper side of the upper lip 12, as indicated here by arrow E2. In this way, a very significant influence is exerted on the possible bending of the upper lip 12.

[0133] It should be noted that the exemplary connecting device 9 shown in the accompanying drawings can be used for any pair of opposite edges 5-6-7-8 in any decorative panel 1 having the features of the first aspect of the invention and / or the specific independent aspects mentioned in the content of the invention, and / or any pair of opposite edges 5-6-7-8 in any decorative panel 1 obtained by the method according to the second aspect of the invention and / or the preferred embodiments of these aspects.

[0134] Fig. 9An exemplary floor panel 1 is shown having a substrate 2 with an integrated reinforcement layer 29A. In this case, it is a woven fiberglass reinforcement layer 29A. The woven fiberglass reinforcement layer 29A has a mesh structure of glass fibers 53 extending in at least two cross directions. Fig. 9 , a cross section of glass fibers 53 extending in the longitudinal direction of the floor panel 1 is shown, while glass fibers extending in the transverse direction of the floor panel 1 are shown in the dotted line 54. The semi-crystalline or crystalline polymer of the substrate 2 continuously passes through the openings 55 of the reinforcing layer 29. In this case, the semi-crystalline polymer 4 continuously passes through the openings 55 of the mesh structure or the interlaced structure. In this example, the reinforcing layer 29A is located in the center of the substrate 2, that is, in the middle, approximately in the middle, or substantially in the middle of the thickness T1 of the substrate 2. Preferably, the two substrate parts 2A-2B on either side of the reinforcing layer 29A have the same or similar composition.

[0135] Fig.10 A method of manufacturing a decorative floor panel 1 having a substrate 2 and a top layer 3 provided thereon is shown. The substrate 2 comprises a semi-crystalline polymer 4. The substrate 2 is provided by an extrusion operation S1, wherein the semi-crystalline polymer 4 is extruded through a die 56. The method shown further comprises a step S2 of actively drawing the extruded semi-crystalline polymer 4 from the die 56. In this case, the extruded semi-crystalline polymer 4 is drawn in a nip 57 of a pair of driven rollers 58, which driven rollers 58 may also perform thickness calibration and / or cooling of the extruded semi-crystalline polymer 4.

[0136] Fig.10 It is further shown that a step S3 of cooling the extruded semi-crystalline polymer 4 may be included in the method of the present invention. Fig.10 It is shown that this can be accomplished by cooling plates 59 preferably in contact with one or more surfaces of the extruded semi-crystalline polymer 4. In this example, the heat treatment occurs downstream of the die 56 and upstream of the subsequent lamination operation S4 and embossing operation S5.

[0137] Fig.11 A variation is shown in which, in step S3 , the extruded semi-crystalline polymer 4 is cooled by spraying water on one or more surfaces of the extruded semi-crystalline polymer 4 using a nozzle 60 .

[0138] Fig.12 A variant is shown in which, in step S3 , the extruded semi-crystalline polymer 4 is cooled in a water bath 61 , wherein the temperature of the water is kept above the glass transition temperature of the semi-crystalline polymer 5 .

[0139] Fig.13A variant is shown, wherein in step S3, the extruded semi-crystalline polymer 4 is heat treated using a further cooled and / or heated roller 62. This additional roller 62 may help to further calibrate the thickness T1 of the extruded semi-crystalline polymer 4.

[0140] It should be noted that the driven roller 58 may be heated or cooled to assist or participate in the heat treatment of step S3.

[0141] exist Fig.10 In the lamination step S4, upstream of the heat treatment step S3, a biaxially oriented polymer film 63 is applied to the extruded semi-crystalline polymer 4 by a heat lamination operation using a roller 64. In this case, the polymer film 63 is a decorative layer 3 having a printed pattern 33. In the lamination step S4, a film 63A is also heat laminated on the bottom of the extruded semi-crystalline polymer 4. It is preferred that the film 63A is oriented in the same manner as the biaxially oriented polymer film 63 applied on top of the extruded semi-crystalline polymer 4.

[0142] As shown, a wear resistant layer 35 (eg, in the form of a transparent biaxially oriented polymer film 63B) may also be applied on top of the printed pattern 33.

[0143] Preferably, at least one orientation axis of the polymer films 63 and 63A is equal or approximately equal. Preferably, the orientation axis of the polymer films 63 and 63A coincides with the orientation direction and / or extrusion direction F of the semi-crystalline polymer 4.

[0144] Fig.10 The method is also shown to include a step S6 of controlling the amount of crystallization of the extruded semi-crystalline polymer 4. In this example, the crystallinity of the semi-crystalline polymer 4 is optically measured by irradiating the extruded semi-crystalline polymer 4 with a light beam 65, collecting the scattered light, and converting the collected light into a Raman spectrum. Then, as shown by the dotted line 66, the information about the crystallinity can be used to change at least one of the extrusion speed, the extrusion temperature, and the temperature of the heat treatment step S3.

[0145] Fig.10 The method is also shown to comprise a step S7 of dividing the extruded semi-crystalline polymer 4 and the applied film 63-63A-63B into panels 1 having the approximate dimensions of the floor panels 1 to be finally obtained. The dividing may be performed by a saw and / or a punch and / or a knife 67.

[0146] The invention is not limited to the preferred embodiment described hereinabove, but such panel and method can be implemented according to several variants without departing from the scope of the invention.

Claims

1. A decorative panel comprising a substrate (2) and a top layer (3) arranged thereon, wherein the substrate (2) comprises at least a semi-crystalline polymer (4), characterized in that: The decorative panel (1) exhibits one or a combination of two or more of the following properties: - the property that the polymer has a crystallinity of less than 85% as measured using differential scanning calorimetry; - the property that the polymer has a crystallinity higher than 35%, preferably higher than 50%; - the property that the polymer is uniaxially oriented; - the property that the top layer comprises a semi-crystalline polymer, wherein the crystallinity of the polymer comprised in the substrate (2) is lower than the crystallinity of the polymer comprised in the decorative top layer (3); - the substrate (2) comprises a plurality of substrate layers, wherein at least two of the plurality of substrate layers comprise properties of a semi-crystalline polymer (4).

2. The decorative panel according to claim 1, characterized in that: The semi-crystalline polymer (4) is selected from the list consisting of polyacetal (POM), polyamide (PA 6 and PA 66), polybutylene terephthalate (PBT), polyethylene terephthalate (PET), low-density polyethylene (LDPE), high-density polyethylene (HDPE), polyphenylene sulfide (PPS), polyetheretherketone (PEEK) and polypropylene (PP).

3. The decorative panel according to claim 1, characterized in that: The substrate (2) comprises a filled synthetic material, wherein the filled synthetic material is formed at least from the semi-crystalline polymer (2) and a filler material.

4. The decorative panel according to claim 3, characterized in that: The filler material comprises a material selected from the list consisting of rice husk, cork, bamboo, sugar cane, foamed synthetic material, porous inorganic material, perlite, vermiculite, selenite and pumice.

5. The decorative panel according to claim 3 or 4, characterized in that: The filler material comprises a material selected from the list consisting of chalk, talc, limestone, CaCO3, sand and SiO2.

6. A decorative panel according to any one of the preceding claims, characterised in that The semi-crystalline polymer (4) is foamed.

7. A decorative panel according to any one of the preceding claims, characterised in that The semi-crystalline polymer is a mixture of polypropylene and ethylene-propylene copolymer or ethylene-propylene-diene copolymer and / or the semi-crystalline polymer is a mixture of polypropylene with an amorphous polymer or copolymer, such as with a cycloolefin polymer or copolymer.

8. Decorative panel comprising a substrate (2) and a top layer (3) arranged thereon, wherein the substrate (2) contains at least a filled synthetic material, wherein the filled synthetic material is formed at least from a preferably thermoplastic polymer and a filling material, characterised in that The filling material comprises a density of 300 kg / m 3 or lower, e.g. 120-180kg / m 3 of filler material, and / or a material selected from the list consisting of rice husk, cork, bamboo, sugar cane, foamed synthetic material, porous inorganic material, perlite, vermiculite, segno stone and pumice.

9. The decorative panel according to claim 8, characterized in that: All or at least 75 vol% of the filler material in the filled synthetic material has a density of 300 kg / m 3 or lower, e.g. 120-180kg / m 3 The filling material, and / or a material selected from the list consisting of rice husk, cork, bamboo, sugar cane, foamed synthetic material, porous inorganic material, perlite, vermiculite, senoite and pumice.

10. The decorative panel according to claim 8, characterized in that: The filling material at least comprises a first part and a second part of filling material, and preferably consists of a first part and a second part of filling material, wherein the first part has a density of 300 kg / m 3 or lower, e.g. 120-180kg / m 3 or less, and / or comprises a material selected from the list consisting of rice husk, cork, bamboo, sugar cane, foamed synthetic material, porous inorganic material, perlite, vermiculite, senoite and pumice, and wherein the second part is a material having a density of 1200 kg / m 3 or higher, for example, density of 1800-3000kg / m 3 of filler material and / or includes a material selected from the list consisting of chalk, talc, limestone, CaCO3, sand and SiO2.

11. The decorative panel according to claim 10, characterized in that: The density of the filler material is within 25% of the density of the polymer, preferably within 20% of the density of the polymer.

12. The decorative panel according to claim 10 or 11, characterized in that: The amount of filler material that can be used in the filled synthetic material is 50% to 250%, or preferably 80% to 200%, expressed as a weight ratio of filler material to synthetic material.

13. The decorative panel according to any one of claims 10 to 12, characterized in that: The amount of filler material that can be used in the filled synthetic material is 50% to 250%, or preferably 80% to 200%, expressed as a weight ratio of filler material to synthetic material.

14. The decorative panel according to any one of claims 10 to 13, characterized in that: The density of the filled synthetic material is within 30% or within 20% of the density of the polymer in question.

15. A method for producing a decorative panel, wherein the panel comprises a substrate (2) and a top layer (3) arranged thereon, wherein the substrate (2) comprises at least a semi-crystalline polymer, wherein the method comprises a step wherein the substrate (2) is provided at least partly by an extrusion operation (S1), wherein the semi-crystalline polymer is extruded through a die (56), characterized in that The method further comprises one or a combination of two or more of the following steps: - a step of cooling the extruded semi-crystalline polymer (4) in a bath (61); - a step of actively drawing the extruded semi-crystalline polymer (4) from the die (56); - a step of adhering a polymer film, preferably a uniaxially or biaxially oriented polymer film (63-63A) to said extruded semi-crystalline polymer (4), or a step of casting a polymer layer directly or indirectly on said extruded semi-crystalline polymer (4); - a step of treating the surface of the extruded semi-crystalline polymer (4) by means of rollers (62) and / or plates (59), wherein the rollers (62) and plates (59) are preferably cooled; - a step of subsequent heat treatment of said extruded semi-crystalline polymer (4), whether or not it is forced to cool; - A step of controlling the amount of crystallinity of said extruded semi-crystalline polymer (4).

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