WATERPROOF PANEL, PROCESS FOR PRODUCING A PANEL, AND PANEL OBTAINABLE BY SAID PROCESS

Abstract

The invention relates to a panel suitable for constructing a waterproof floor or wall covering, wherein the panel has a substantially planar top surface, a substantially planar bottom surface, and at least four substantially linear side edges. The invention also relates to a process for producing a panel according to the invention. The invention further relates to a panel obtainable by said process according to the invention.

Claims

1-40. (canceled)

41. A panel suitable for constructing a waterproof floor or wall covering, wherein the panel has a substantially planar top surface, a substantially planar bottom surface, and at least four substantially linear side edges, wherein the panel has a laminate structure which comprises: a rigid core layer basically composed of a composite material comprising a mixture of mineral material and thermoplastic material, a top layer fixed to the core layer, wherein the composite material contains a ratio of weight percentages of mineral material relative to thermoplastic material which is 1 or larger, and wherein the mixture comprises one or more thermoplastic materials chosen from the group of: polyethylene, polypropylene and copolymers thereof.

42. The panel according to claim 41, wherein the mixture further comprises one or more thermoplastic materials chosen from the group consisting of: polyvinyl acetate, polyvinyl alcohol, vinyl and vinylidene resins and copolymers thereof, acrylonitrile butadiene styrene, styrene acrylonitrile resin, polystyrenes and copolymers thereof, saturated and unsaturated polyesters, acrylics, polyamides, nylon containing polyamides, engineering plastics, acetyl, polycarbonate, polyimide, polysulfone, polyphenylene oxide and sulfide resins.

43. The panel according to claim 41, wherein the core layer further comprises one or more conductive thermoplastic polymers.

44. The panel according to claim 41, wherein the composite material comprises at least 60% by weight of mineral filler.

45. The panel according to claim 41, wherein the composite material comprises at least 15% by weight of thermoplastic material.

46. The panel according to claim 41, wherein the composite material comprises one or more additives chosen from the group consisting of: a pigment, an impact modifier, an internal lubricant, an external lubricant, a stabilizer, a wax, and/or an aid processing agent.

47. The panel according to claim 46, wherein at least one impact modifier comprises methacrylate butadiene styrene, acrylonitrile butadiene styrene and/or a thermoplastic elastomer.

48. The panel according to claim 46, wherein at least one stabilizer is a calcium zinc stabilizer, barium-cadmium stabilizers, barium-zinc stabilizers, organotin stabilizers or epoxidized soybean oils.

49. The panel according to claim 46, wherein the total amount of additives present in the composite core layer is restricted to 1-15% by weight.

50. The panel according to claim 41, wherein the core layer comprises organic fibres.

51. The panel according to claim 41, wherein the composite material comprises at least one bio plasticizer in an amount less than 5 wt. %, which bio plasticizer is a plasticizers derived from vegetable oils or an epoxy-functional bio-derived plasticizer formed by an epoxy-functional fatty acid ester obtained from a vegetable oil selected from the group consisting of soybean oil, canola oil, corn oil, linseed oil, rapeseed oil, safflower oil, sunflower oil, tall oil, tung oil, and mixtures and derivatives thereof.

52. The panel according to claim 41, wherein at least thermoplastic polymer is a recycled thermoplastic polymer.

53. The panel according to claim 41, at least part of the core layer has a cellular foam structure core.

54. The panel according to claim 41, wherein the rigid core layer comprises at least one mineral material selected from the group consisting of: magnesium oxide, calcium carbonate, chalk, clay, limestone, calcium silicate, and talc.

55. The panel according to claim 41, wherein the density of the composite material is situated in between 1500 and 2200 kg/m.sup.3.

56. The panel according to claim 41, wherein the core layer is an extruded layer formed by an extrusion process or wherein the top layer is an extruded layer formed by an extrusion process or wherein the core layer and the top layer are formed by a co-extrusion process.

57. The panel according to claim 41, wherein the top layer is a veneer layer adhered to a top surface of the core layer.

58. Panel according to claim 57, wherein the veneer layer is selected from the group consisting of wood veneer, cork veneer, bamboo veneer, tile veneer, stone veneer, rubber veneer, decorative plastic veneer, linoleum veneer and decorative vinyl veneer.

59. The panel according to claim 41, wherein the core layer and the top layer are fixed to each other by virtue of a fusion bonding which has been formed under heat and pressure.

60. A process for producing a panel according to claim 41, wherein the core layer and the top layer are fixed to each other in a fusion step wherein heat and pressure are applied to an assembly of the core layer and the top layer, and during which step a fusion bonding is established, wherein the process is a continuous process including the steps of: preparing a composite material by mixing of the compounds included in the composite material; extruding a molten core layer of the composite material using an extruder; leading the molten core layer over rollers; providing a top layer and leading the top layer towards an upper surface of the molten core layer wherein the bottom surface of the top layer is applied onto the upper surface of the molten layer to obtain an assembled structure; applying pressure and heat on the assembled structure such that a fusion bonding is established between the top layer and the molten core layer; cooling of the assembled structure after formation of the fusion bonding.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0060] FIG. 1 shows schematically the process by which the laminate material for the panel is produced.

EXAMPLES

[0061] The invention will be further explained by the following examples which represents a preferred embodiment of the invention.

Example 1

[0062] A laminate structure was formed based on a core layer and a top layer, which top layer is composed of a decorative layer, and a wear layer.

[0063] The materials from which each layer is formed, are given in the below table.

TABLE-US-00001 amount compound (wt. %) Wear layer PVC 75 Plasticizer (oiled based 20 or bio compound) Additive 5 Decorative layer PVC 90 Plasticizer 5 Additive 5 Core layer Calcium Carbonate 50-60 PVC 30-40 Additive 10

[0064] The additive in all layers is a mixture of a lubricant (internal and external), wax (PE wax for example), stabilizer (for thermal stability), processing aid and pigment.

[0065] The wear layer has a thickness of 0.1 to 1 mm, and the decorative layer has a thickness of 0.05 to 0.1 mm. The core layer has a thickness of 2 to 20 mm, preferably from 2.5 to 5 mm.

[0066] The panel obtained from the above material, had a rigidity, expressed as the elasticity modulus of the board according to EN 310, of approx. 4000 MPa.

[0067] The top layer 1 consisting of a wear layer fixed onto a decorative layer that have been fused together in a separate process, is provided on a roll 3.

[0068] The compounds included in the composition for the core layer are mixed in a suitable mixer 5 and the obtained raw mixture of material is led into an extruder 7. The extruder expels a melted core layer 9 which is led through two counter rollers 11.

[0069] At the nip between the counter rollers 11, the top layer 1 is merged with the melted core layer 9. The melted core layer is hot and flexible at this stage. The top layer 1 is led over a heating roller 13, which pre-heats the top layer 1 before it merges with the core layer 9.

[0070] During the passage through the nip of the counter rollers 11, pressure is exerted on the merged structure of top layer and core layer. The counter rollers 11 are heated so that an optimum temperature is assured for the formation of a fusion bonding between the top layer 1 and the core layer 9.

[0071] Subsequently, the obtained sheet of laminate material 15 is allowed to cool off, and finally led towards a cutting station (not shown) in which the laminate sheet material is cut into panel pieces.

[0072] Optionally, the opposite side edges of the cut panel pieces are furthermore provided with interconnecting coupling means for interconnecting one panel with another.

[0073] In Examples 2-4, alternative, exemplary compositions are given, which may also be used in a waterproof panel according to the invention.

Example 2

[0074]

TABLE-US-00002 amount compound (wt. %) Wear layer PVC 80 Plasticizer (oiled based 0 or bio compound) Additive 20 Decorative layer PVC 90 Plasticizer 0 Additive 10 Core layer Calcium Carbonate 65-70 PVC 25-30 Additive Stabilizer 2.7-3.1 MBS 0.5-1.3 Wax 0.5-0.9 Plasticizer 0 Aid processing 1.2-2.3

Example 3

[0075]

TABLE-US-00003 amount Compound (wt. %) Wear layer Paper 20-40 Melamine resin 60-80 Decorative layer Paper 40-60 Melamine resin 40-60 Sublayer layer Kraft paper 40-60 Melamine resin 40-60 Core layer Calcium Carbonate 65-70 Plasticizer 0 PVC 25-30 Additive 4-7

Example 4

[0076]

TABLE-US-00004 amount Compound (wt. %) Wear layer Paper 20-40 Melamine resin 60-80 Decorative layer Paper 40-60 Melamine resin 40-60 Sublayer layer Kraft paper 0 Melamine resin 0 Core layer Sublayer 1 Wood dust 40-50 PVC 40-50 Additive 4-7 Sublayer 2 Calcium Carbonate 65-70 Plasticizer 0 PVC 25-30 Additive 4-7 Sublayer 3 Wood dust 40-50 PVC 40-50 Additive 4-7