DECORATIVE PANEL

Abstract

A decorative panel includes a substrate and a wear layer. The wear layer has a varnish coat that includes hard particles over its entire thickness. The hard particles have an S50 particle size determined from the cumulative particle size distribution according to volume measured by laser diffraction as the particle size at which 50% of the hard particles are smaller than this particle size S50. The varnish coat has a thickness T that is between 0.5*S50 and 2*S50.

Claims

1.-82. (canceled)

83. A decorative panel, wherein the decorative panel comprises a substrate and a wear layer, wherein the wear layer comprises a varnish coat, wherein the varnish coat comprises hard particles over the entire thickness, wherein the hard particles have an S50 particle size, wherein the S50 particle size, determined from the cumulative particle size distribution according to volume measured by laser diffraction, is the particle size at which 50% of the hard particles are smaller than this particle size S50; in that the varnish coat has a thickness T; and in that the thickness T of the varnish coat is between 0.5*S50 and 2*S50; wherein the varnish coat is an acrylate varnish coat.

84. The decorative panel as in claim 83, wherein the varnish coat is an acrylate varnish coat, wherein the acrylate varnish coat is obtained using at least 0.1 wt % of dendritic oligomer with an acrylate functionality of 5 or higher, wherein this percentage by weight is determined relative to the total weight of the varnish coat.

85. The decorative panel as in claim 83, wherein the S50 particle size is between 3 micrometers and 20 micrometers.

86. The decorative panel as in claim 83, wherein the hard particles have a particle size distribution according to volume wherein (S95-S5)/S50 is less than 2; wherein S95 in the particle size distribution according to volume as determined by laser diffraction is the particle size at which 95% of the particles are smaller; and wherein S5 in the particle size distribution according to volume as determined by laser diffraction is the particle size at which 5% of the particles are smaller.

87. The decorative panel as in claim 83, wherein the hard particles have a particle size distribution according to volume wherein (S95-S50)/S50 is less than 1; wherein S95 in the particle size distribution according to volume as determined by laser diffraction is the particle size at which 95% of the particles are smaller.

88. The decorative panel as in claim 83, wherein the varnish coat comprises between 2 and 15 wt % of hard particles.

89. The decorative panel as in claim 83, wherein the hard particles have a Mohs hardness higher than 7.

90. The decorative panel as in claim 83, wherein the hard particles comprise a silane coating.

91. The decorative panel as in claim 83, wherein a second varnish coat is located underneath the varnish coat; wherein this second varnish coat is an acrylate varnish coat; wherein this second varnish coat contacts the varnish coat; and wherein the second varnish coat does not comprise any particles with Mohs hardness higher than 7.

92. The decorative panel as in claim 83, wherein the panel comprises a decorative layer, wherein the decorative layer is located underneath the wear layer or the decorative layer is formed by the upper surface of the substrate.

93. The decorative panel as in claim 92, wherein the decorative layer comprises a print on the substrate or a print on a carrier.

94. The decorative panel as in claim 93, wherein the wear layer comprises an additional layer, situated closer to the substrate than the varnish coat, wherein the additional layer comprises a polymer film.

95. The decorative panel as in claim 94, wherein the additional layer comprises a polyvinyl chloride film, with a thickness between 20 micrometers and 550 micrometers.

96. The decorative panel as in claim 95, wherein the polymer film is a polymer film with a hardness of at least 60 Shore D.

97. The decorative panel as in claim 95, wherein the polymer film is a polyvinyl chloride film that comprises less than 20 wt % of plasticizer.

98. The decorative panel as in claim 94, wherein the surface of the panel comprises a texture, wherein the texture reaches at least into the additional layer.

99. The decorative panel as in claim 83, wherein the substrate consists of or comprises one or more of a wood fiber board, including an MDF board (Medium Density Fiberboard) or an HDF board (High Density Fiberboard); a chipboard; one or more layers of filled or unfilled polymer; one or more layers that comprise a mineral matrix with fillers; for example a mineral matrix based on Portland cement or on magnesium oxide or on gypsum; one or more layers of wood; or one or more resin-impregnated layers of kraft paper.

100. The decorative panel as in claim 83, wherein the surface of the panel comprises a texture.

101. The decorative panel as in claim 83, wherein the panel comprises a first pair of opposite edges, including a first edge and a second edge, wherein the first pair of opposite edges comprises coupling parts, wherein these coupling parts comprise locking parts, so that the panel can be coupled with its first edge to the second edge of another such panel so that on the one hand locking is obtained in the direction perpendicular to the plane of the panels thus coupled, and on the other hand locking is obtained in the direction in the plane of the coupled panels perpendicular to the coupled panels.

Description

[0123] For better illustration of the features of the invention, some preferred embodiments are described hereunder, as examples without any limiting character, referring to the appended drawings, in which:

[0124] FIG. 1 illustrates the cumulative particle size distribution;

[0125] FIGS. 2-6 show the structure of examples of decorative panels according to the invention;

[0126] FIG. 7 shows, schematically and in perspective, a portion of a floor covering that consists of floor panels according to the invention;

[0127] FIG. 8 shows, on a larger scale, the portion that is indicated as F8 in FIG. 7;

[0128] FIG. 9 shows a top view of a floor panel from the floor covering in FIGS. 7 and 8; and

[0129] FIGS. 10 and 11 show, on a larger scale, cross sections according to cross sections X-X and XI-XI, respectively, in FIG. 9.

[0130] FIG. 1 illustrates the cumulative particle size distribution of hard particles such as applied in the invention. The particle size A (in micrometers) is plotted on the horizontal axis. The cumulative distribution according to volume of the particles, in percent, as determined by laser diffraction, is plotted on the vertical axis (B). The particle sizes S5, S50 and S95 are indicated in FIG. 6. S50 is the particle size at which 50% of the hard particles are smaller than this particle size S50. S95 is the particle size at which 95% of the particles are smaller than this particle size S95. S5 is the particle size at which 5% of the particles are smaller than this particle size S5.

[0131] An example of a recipe that may be used for a varnish coat, which may be cured by means of UV radiation, according to the invention is for example: [0132] 5-85 wt % of oligomer of an acrylate (for example a polyester acrylate, a polyether acrylate, an epoxy acrylate, a urethane acrylate or combinations of these types of acrylates), [0133] 5-60 wt % monomers, for example mono- or bifunctional acrylate monomers, [0134] 0.05-10 wt % photoinitiator and/or thermal initiator, [0135] 0.5-2 wt % antifoaming agent, [0136] 0.5-2 wt % wetting agent, [0137] 0.05-2 wt % leveling agent, [0138] 2-15 wt % of hard particles, [0139] optionally 0.05-10 wt % anti-slip agents, [0140] optionally 0.05-15 wt % matting agent, for example silica [0141] optionally 0.05-5 wt % UV or HALS absorbers.

[0142] A second example of a recipe that may be used for a varnish coat, which may be cured by means of UV radiation, according to the invention is for example: [0143] 5-85 wt % of oligomer of an acrylate (for example a polyester acrylate, a polyether acrylate, an epoxy acrylate, a urethane acrylate or combinations of these types of acrylates), [0144] 1-15 wt % of dendritic oligomer with an acrylate functionality of 5 or higher, [0145] 5-60 wt % monomers, for example mono- or bifunctional acrylate monomers, [0146] 0.05-10 wt % photoinitiator and/or thermal initiator, [0147] 0.5-2 wt % antifoaming agent, [0148] 0.5-2 wt % wetting agent, [0149] 0.05-2 wt % leveling agent, [0150] 2-15 wt % of hard particles, [0151] optionally 0.05-10 wt % anti-slip agents, [0152] optionally 0.05-15 wt % matting agent, for example silica [0153] optionally 0.05-5 wt % UV or HALS absorbers.

[0154] Examples of hard particles that are usable in these (or other) recipes for varnish coats according to the invention are: [0155] Diamond particles, for example with S50 equal to 14 micrometers, S5 equal to 9 micrometers and S95 equal to 24 micrometers. [0156] Diamond particles, for example with S50 equal to 6 micrometers, S5 equal to 3 micrometers and S95 equal to 11 micrometers. [0157] Aluminum oxide particles, for example with S50 equal to 13.4 micrometers, S5 equal to 6.1 micrometers and S95 equal to 23.8 micrometers. [0158] Aluminum oxide particles, for example with S50 equal to 7.7 micrometers, S5 equal to 2.7 micrometers and S95 equal to 14.9 micrometers. [0159] Aluminum oxide particles, for example with S50 equal to 4.4 micrometers, S5 equal to 0.9 micrometers and S95 equal to 9.4 micrometers.

[0160] FIGS. 2-6 show the structure of examples of decorative panels according to the invention.

[0161] FIG. 2 shows the structure of a decorative panel according to the invention. The decorative panel comprises a substrate 31, a decorative layer 32, and a wear layer 33. The substrate may for example be a wood-based substrate, for example consisting of several layers 31A, 31B. The decorative layer may for example be a printed layer of paper, impregnated with a thermosetting resin, for example a melamine formaldehyde resin or an acrylate resin.

[0162] The wear layer 33 comprises a varnish coat 35 (of thickness T), which forms the surface of the panel, and a second varnish coat 40. In the example, both the varnish coat 35 and the second varnish coat 40 are acrylate varnish coats, applied as 100% acrylate varnishes (i.e. the varnish applied in liquid form comprises neither water nor some other solvents), which has first been gelled by means of UV radiation and further cured in a heated pressing operation. The varnish coat 35 is placed on and contacts the second varnish coat 40. The second varnish coat 40 does not comprise any particles with Mohs hardness higher than 7 and has a thickness T3; which is preferably between half and twice the thickness T of the varnish coat 35.

[0163] The varnish coat 35 comprises hard particles 36 over the entire thickness. The thickness T of the varnish coat is 20 micrometers. The varnish coat 35 comprises for example 8 wt % of hard particles 36. In this example the hard particles are diamond particles with S50 equal to 14 micrometers, S5 equal to 9 micrometers and S95 equal to 24 micrometers.

[0164] The surface of the panel comprises a surface structure, pressed therein by means of a press surface with texture. In this pressing operation, the decorative paperwith the varnish coats thereon in the gelled stateis laminated on the substrate, wherein the thermosetting resins are cured, including the varnish coat and the second varnish coat.

[0165] Optionallynot shown in FIG. 2an adhesion layer may be applied on one or on both sides of the decorative layer, for example applied as a water-based polyurethane dispersion. This adhesion layer may be used in order to improve the adhesion between the respective layers in the decorative panel.

[0166] FIG. 3 shows the structure of a decorative panel according to the invention. The decorative panel comprises a substrate 31, a decorative layer 32, and a wear layer 33. The substrate may for example be a wood-based substrate, for example consisting of several layers 31A, 31B. The decorative layer may for example be a printed layer of paper, impregnated with a thermosetting resin, for example a melamine formaldehyde resin or an acrylate resin.

[0167] The wear layer 33 comprises a varnish coat 35 (of thickness T), which forms the surface of the panel, and a second varnish coat 40. In the example, both the varnish coat 35 and the second varnish coat 40 are acrylate varnish coats, applied as 100% acrylate varnishes (i.e. the varnish applied in liquid form comprises neither water nor some other solvent), which had first been gelled by means of UV radiation and was cured further in a heated pressing operation. The varnish coat 35 is placed on and contacts the second varnish coat 40.

[0168] The varnish coat 35 comprises hard particles 36 over the entire thickness. The thickness T of the varnish coat is 20 micrometers. The varnish coat 35 comprises for example 8 wt % of hard particles. In this example the hard particles are diamond particles with S50 equal to 14 micrometers, S5 equal to 9 micrometers and S95 equal to 24 micrometers.

[0169] The second varnish coat 40 comprises, over its entire thickness T3, hard particles 43, for example aluminum oxide particles, for example with average particle size (meaning the S50 particle size) of 90 micrometers. The thickness T3 of the second varnish coat 40 is preferably between 150 and 250 micrometers, more preferably between 180 and 200 micrometers.

[0170] The surface of the panel comprises a surface structure, pressed therein by means of a press surface with texture. In this pressing operation, the decorative paperwith the varnish coats thereon in the gelled statewas laminated on the substrate, wherein the thermosetting resins are cured, including the varnish coat and the second varnish coat.

[0171] Optionallynot shown in FIG. 3an adhesion layer may be applied on one or on both sides of the decorative layer, for example applied as a water-based polyurethane dispersion. This adhesion layer may be used in order to improve the adhesion between the respective layers in the decorative panel.

[0172] FIG. 4 shows another example of a floor panel according to the invention. This decorative floor panel comprises a substrate 31, a decorative layer 32, and a wear layer 33. The substrate 31 may for example consist of one or more polyvinyl chloride layers, with fillers. One or more of these layers may be foamed. One or more of these layers may be rigid or flexible polyvinyl chloride layers, depending on the amount of plasticizers that they contain.

[0173] The decorative layer 32 may be a printed polymer film, for example a printed polyvinyl chloride film with a thickness of 90 micrometers.

[0174] The wear layer 33 comprises a polymer film 42, for example a polyvinyl chloride film with a thickness between 20 micrometers and 500 micrometers. For example with a thickness of 300 micrometers.

[0175] The wear layer 33 further comprises a varnish coat 35 (of thickness T), which forms the surface of the panel. In the example in FIG. 4, the varnish coat 35 was applied as 100% acrylate varnish (i.e. the varnish applied in liquid form comprises neither water nor some other solvent). In the example the varnish coat 35 was applied after the thermal laminating of the substrate 31, the printed polymer film that forms the decorative layer 32 and the polymer film 42; and after the texturing of this laminate by means of a textured heated roller. The varnish coat 35 is applied so that a texture is preserved in the surface of the panel. After liquid application of the varnish coat 35 it is cured by means of UV radiation.

[0176] Alternatively, it is also possible not to press a texture in the surface after lamination of the various layers, apply the varnish coat as a liquid and gel it by means of UV radiation; and then press a texture in the surface of the panel by means of a heated textured roll. As a result of this thermal treatmentand optionally a thermal post-treatmentthe varnish coat is then fully cured.

[0177] The varnish coat 35 comprises hard particles 36 over the entire thickness T. The thickness T of the varnish coat is 15 micrometers. The varnish coat 35 comprises for example 10 wt % of hard particles. In this example the hard particles are aluminum oxide particles with S50 equal to 13.4 micrometers, S5 equal to 6.1 micrometers and S95 equal to 23.9 micrometers. Other thicknesses and another selection of particles are possible within the scope of the invention.

[0178] FIG. 5 shows another example of a floor panel according to the invention. This example is broadly similar to the example shown in FIG. 4. Identical reference numbers thus have the same meaning.

[0179] The panel in FIG. 5 differs from the panel in FIG. 4 by a difference in the varnish coat 35 and the presence of a second varnish coat 40. In this example the varnish coat 35 has a thickness T of 10 micrometers. This varnish coat comprises hard particles 36 over its entire thickness T. The varnish coat 35 comprises for example 10 wt % of hard particles. In this example the hard particles are aluminum oxide particles with S50 equal to 7.7 micrometers, S5 equal to 2.7 micrometers and S95 equal to 15 micrometers.

[0180] The varnish coat 35 is applied on a second varnish coat 40, which has a thickness of 10 micrometers and does not comprise any particles with Mohs hardness greater than 7.

[0181] In the example, the varnish coat 35 and the second varnish coat 40 are acrylate varnish coats. The second varnish coat 40 functions as an adhesion layer for the varnish coat 35.

[0182] The varnish coat 35 may be applied and cured in the same way as described in the example shown in FIG. 4.

[0183] FIG. 6 illustrates another example of a floor panel according to the invention. This example is broadly similar to the example shown in FIG. 4. Identical reference numbers thus have the same meaning.

[0184] The panel in FIG. 6 differs from the panel in FIG. 4 by a difference in the structure of the wear layer 33. The wear layer 33 comprises a polymer film 42, for example a polyvinyl chloride film with a thickness between 20 micrometers and 500 micrometers. For example with a thickness of 300 micrometers. The wear layer 33 further comprises a varnish coat 35. The varnish coat 35 is built up from a first partial varnish coat 45 with thickness T1 and a second partial varnish coat 46 with thickness T2. The second partial varnish coat 46 is applied on the first partial varnish coat 45. In the example a first partial varnish coat 45 has a thickness T1 equal to 10 micrometers; and the second partial varnish coat 46 has a thickness T2 equal to 10 micrometers.

[0185] The first partial varnish coat 45 and the second partial varnish coat 46 have the same composition and are acrylate varnish coats, applied as liquid varnish. Both the first partial varnish coat 45 and the second partial varnish coat 46 comprise 10 wt % of hard particles 36. In this example the hard particles are aluminum oxide particles with S50 equal to 7.7 micrometers, S5 equal to 2.7 micrometers and S95 equal to 15 micrometers.

[0186] After applying the first partial varnish coat 45, the second partial varnish coat 46 may be applied. The panel may be provided with a surface texture in the same way as described in FIG. 4.

[0187] In the example in FIG. 6, the first partial varnish coat and the second partial varnish coat have the same composition. This need not necessarily be so for the invention.

[0188] FIG. 7 shows, schematically and in perspective, a portion of a floor covering that consists of floor panels according to the invention. FIG. 8 shows on a larger scale the portion that is indicated with F8 in FIG. 7. FIG. 9 shows a top view of a floor panel from the floor covering in FIGS. 7 and 8. FIGS. 10 and 11 show, on a larger scale, cross sections according to cross sections X-X and XI-XI respectively in FIG. 9. The panels comprise a substrate 31, a decorative layer 32 and a wear layer 33 according to the invention.

[0189] FIGS. 7 and 8 show floor panels 1 according to the invention for forming a floor covering. These floor panels 1 comprise a first pair of opposite edges 2-3 and a second pair of opposite edges 4-5.

[0190] The floor panels 1 shown are configured on their edges in such a way that they are mutually couplable according to the so-called fold-down principle, which is a principle that is known per se, and that consists in that said floor panels 1 can be coupled to each other on the first pair of edges 2-3 by a rolling motion R, and can be coupled to each other on the second pair of edges 4-5 by a downward motion M, wherein the downward motion M is a consequence of the rolling motion R and thus occurs substantially at the same time. The floor panels 1 are also configured on their edges 2-3 and 4-5 in such a way that finally locking occurs in the vertical direction V and in the horizontal direction H, the latter being perpendicular to the respective edges.

[0191] As shown in FIGS. 10 and 11, said floor panel 1 is provided for this purpose on its first pair of edges 2-3 with coupling parts 6-7, while on the second pair of edges 4, 5, coupling parts 8-9 are provided, said coupling parts being described in more detail hereunder with reference to FIGS. 10 and 11.

[0192] The coupling parts 8-9 of the second pair of edges 4-5 have, as can be seen in FIG. 10, at least the following basic features:

the coupling parts 8-9 comprise a horizontally acting locking system, which in a coupled state of two of said floor panels 1 achieves locking in the plane of the floor panels 1 and perpendicular to the respective edges 4-5;
the coupling parts 8-9 also comprise a vertically acting locking system, which in a coupled state of two of said floor panels 1 achieves locking transversely to the plane of the floor panels 1;
the coupling parts 8-9 are mainly made from the material of the floor panel 1 itself;
the horizontally acting locking system of the second pair of edges 4-5 is at least formed from an upward directed lower hook-shaped portion 10 that is located on one of the aforementioned two edges, in this case edge 4, as well as a downward directed upper hook-shaped portion 11 that is located on the opposite edge 5, wherein the lower hook-shaped portion 10 consists of a lip 12 with an upward directed locking element 13 which, proximally therefrom, defines a female part 14 in the form of a recess, whereas the upper hook-shaped portion 11 consists of a lip 15 with a downward directed locking element 16 that forms a male part 17;
the coupling parts 8-9 are configured in such a way that two of said floor panels 1 can be coupled to each other on their respective edges 4-5 by means of a downward motion M of one floor panel relative to another;
the vertically acting locking system comprises vertically acting locking parts 18-19-20-21 which define, by means of respective contact surfaces 22-23-24-25, at least one first contact zone and a second contact zone, which are located on either side of the male part 17 and the female part 14; the aforementioned vertically acting locking parts comprise a first locking part 18 and a second locking part 19 on the respective opposite sides 26-27 of the male part 17, as well as a third locking part 20 and a fourth locking part 21 on the respective opposite sides 28-29 of the female part 14, in other words on the sides that are located on either side of the recess that forms the female part;
the first and third locking part 18 and 20 respectively define, in the coupled state of two of said floor panels 1, the aforementioned first contact zone, wherein they have contact surfaces 22 and 24 respectively, which in the coupled state define at least one inclined tangent;
the second and fourth locking part 19 and 21 respectively define, in the coupled state of two of said floor panels 1, the aforementioned second contact zone, wherein they have contact surfaces 23 and 25 respectively, which in the coupled state also define at least one inclined tangent;
the aforementioned male part 17 has a distal side 27 and a proximal side 26, wherein the second locking part 19 is located on the distal side 27; and
the aforementioned two tangents are inclined upward toward each other from their respective contact zones.

[0193] The coupling parts 6-7 of the first pair of edges 2-3 have, as can be seen in FIG. 11, at least the following basic features:

the coupling parts 6-7 comprise a horizontally acting locking system HL, which in a coupled state of two of said floor panels 1 achieves locking in the plane of the floor panels 1 and perpendicular to the respective edges 2-3;
the coupling parts 6-7 also comprise a vertically acting locking system VL, which in a coupled state of two of said floor panels 1 achieves locking transversely to the plane of the floor panels, in other words in the vertical direction;
the coupling parts 6-7 are mainly made from the material of the floor panel 1 itself; and
the coupling parts 6-7 are configured in such a way that two of said floor panels 1 can be coupled to each other on these edges by means of a rolling motion R.

[0194] FIGS. 7-11 illustrate the application of panels according to the invention as a floor panel. The panels according to the invention may, however, also be used for other applications. FIGS. 7-11 also illustrate coupling parts that panels according to the invention may comprise. In each of the examples of panels that are shown in FIGS. 2-6, coupling parts may be provided as illustrated in FIGS. 7-11. The coupling parts that may be applied are also not limited to those illustrated in the figures.

[0195] Comparative tests of decorative panels according to the invention were carried out, in which the carrier layer is a polyvinyl chloride film.

[0196] In a first test the polyvinyl chloride film comprised between 30-36 parts by weight of DOTP (dioctyl terephthalate, a plasticizer) and 1-4 parts by weight of ESBO (epoxidized soybean oil, a plasticizer). This polyvinyl chloride film had a hardness of 52 Shore D. The scratch resistance was measured by means of a sclerometer. The result was 6 newton.

[0197] In a second test the polyvinyl chloride film comprised between 10-20 parts by weight of DOTP (dioctyl terephthalate, a plasticizer); and no other plasticizers. This polyvinyl chloride film had a hardness of 75 Shore D. The scratch resistance was measured by means of a sclerometer. The result was more than 10 newton. In the sclerometer, a standardized diamond head is dragged over the test material. The compressive force with which the diamond head presses on the test material and generates a visible scratch is determined. The result of the second test is thus better than the result of the first test.

[0198] The present invention is by no means limited to the embodiments described above; the invention may be carried out according to several variants while remaining within the scope of the present invention.