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EP-4741572-A2 - BOARD, METHOD FOR MANUFACTURING A BOARD AND A PANEL COMPRISING SUCH BOARD MATERIAL

EP4741572A2EP 4741572 A2EP4741572 A2EP 4741572A2EP-4741572-A2

Abstract

Board, wherein the board (11) is based on MgO and MgChloride or wherein the board (11) is based on MgO and MgSulphate, characterized in that the board (11) comprises plant fibers.

Inventors

  • CLEMENT, BENJAMIN
  • MEIRLAEN, José
  • SEYNAEVE, Marijn

Assignees

  • Unilin, BV

Dates

Publication Date
20260513
Application Date
20210202

Claims (15)

  1. Board, wherein the board (11) is based on MgO and MgChloride or wherein the board (11) is based on MgO and MgSulphate, characterized in that the board (11) comprises plant fibers.
  2. Board in accordance with claim 1, characterized in that the plant fibers are selected from wood fibers, bamboo fibers and straw fibers.
  3. Board in accordance with any one of the preceding claims, characterized in that the board (11), or any layer of the board (11), comprises said plant fibers in an amount of at most 95 vol%, preferably at most 90 vol%, and/or in an amount of at most 90 wt%, preferably at most 80 wt%.
  4. Board in accordance with any one of the preceding claims, characterized in that the board (11) comprises wood fibers in an amount of more than 50 vol%.
  5. Board in accordance with any one of the preceding claims, characterized in that the board has a residual moisture content of 7% or below, preferably 5% or below, or even more preferably 4% or below.
  6. Board in accordance with any one of the preceding claims, characterized in that the board (11) comprises alkali resistant binders, wherein the alkali resistant binder are preferably chosen from the list consisting of latex, acrylic, polyurethane, polyvinyl alchohol (PVA), ethylene vinylacetate (EVA), PVAc dispersion, acrylic styrene emulsion, silicate glue (waterglass), solvent based one component or two component, e.g. polyurethane, resin, silane and siloxanes.
  7. Board in accordance with any one of the preceding claims, characterized in that the board (11) comprises separate fibers, wherein said separate fibers are preferably chosen from the list consisting of glass fibers, PVA fibers and cellulose fibers.
  8. Board in accordance with any one of the preceding claims, characterized in that the board (11) is free from glass fiber nets or unwoven structures.
  9. Board in accordance with any one of the preceding claims, characterized in that the board (11) comprises a plurality of layers having a different composition, wherein at least one of said layers is based on MgO and MgChloride, in other words a layer of so called MOC or magnesiumoxychloride, and/or wherein at least one of said layers is based on MgO and MgSulphate, in other words a layer of so-called MOS or magnesiumoxysulphate.
  10. Board in accordance with claim 9, characterized in that the board (11) is symmetric through its thickness (T).
  11. Method for manufacturing a board as in any one of the preceding claims, wherein the method comprises the step of providing a mixture of at least MgO with MgChloride or of providing a mixture of at least MgO with MgSulphate; and the step of adding citric acid and/or alkali resistant binders and/or separate fibers.
  12. Method for manufacturing a coated panel, wherein a board (11) in accordance with any one of the preceding claims is provided with a decorative layer (12), preferably by means of a press operation wherein a melamine treated paper sheet (17) is heat pressed to said board (11).
  13. Method in accordance with claim 12, characterized in that - said board (11) comprises metal soap, silanes, siloxanes and/or siliconates or a combination of both; and/or - said board comprises at at least one, and preferably at both, flat sides a chloride and/or sulphate leaching barrier, such as an aluminum foil or a coating with a thermoplastic material; and/or - said board at at least one edge, and preferably at least at two opposite edges, or at all edges, is treated with a sealant, e.g. an alkali resistant sealant; preferably the treated edges are profiled and comprise coupling means or coupling parts allowing to couple two such boards at the respective edges, wherein a vertical locking perpendicular to the plane of coupled panels and/or a horizontal locking perpendicular to the respective edges and in the plane of the coupled panels is obtained.
  14. Floor, wall, ceiling or furniture panel comprising a board (11) in accordance with any one of the claims 1-10, or obtained via a method in accordance with any one of the claims 11-13, and a provided thereon decorative top layer (12).
  15. Panel in accordance with claim 14, characterized in that the board (11) is provided at at least two opposite edges (2-3;4-5) with coupling means (6) allowing to couple two such panels (1) at the respective edges (2-3; 4-5), wherein a vertical locking in a direction V1 perpendicular to the plane of coupled panels (1) and/or a horizontal locking in a direction H1 perpendicular to the respective edges (2-3; 4-5) and in the plane of the coupled panels (1) is obtained.

Description

The present invention relates to boards and coated panels comprising such boards, as well as to methods for manufacturing boards and coated panels comprising such boards. In the field of decorative surfaces, such as floor panels or furniture panels several types of board materials have been in use. WO 97/47834 and WO 2010/070605 disclose the use of wood-based panels, such as MDF or HDF or wood particle board. Such panels have the disadvantage of being prone to damage due to absorption of water and lack dimensional stability in a climate with changing relative humidity. WO 2011/077311 and WO 2011/141849 disclose plastic based boards that in some cases may comprise filler materials and/or may be foamed, such as boards comprising closed cell foamed Polyvinyl chloride (PVC). These boards are resistant to water or moisture, but sometimes lack rigidity and still lack dimensional stability when exposed to a climate with changing temperature. WO 2006/108,446, WO 2017/172959 and WO 2019/064113 disclose mineral based boards for example based on Portland cement or magnesiumoxide (MgO), also known as Sorel cement. These boards are a lot more dimensional stable than the wood-based or plastic-based boards of the prior art. These boards are however prone to absorption of water and long term disadvantageous effects may originate as a result. Furthermore these boards are brittle and difficult to provide with a qualitative and lasting glueless coupling system. In WO 2019/064113 it is proposed to incorporate two glass fiber fabrics in the critical areas of the click system in order to prevention damage and subsequent loss of strength. Furthermore, decoration of such boards with e.g. melamine based top layers may be challenging, especially using short cycle presses in e.g. a DPL process in which one or more resin provided paper layers are cured, consolidated and adhered to a board using a heated pressing operation. The obtained delamination strength may be in sufficient. The present invention in particular concerns new types of boards that are based on MgO and MgChloride (a board of so called MOC or magnesiumoxychloride) or that are based on MgO and MgSulphate (a board of so-called MOS or magnesiumoxysulphate). Such boards are known per se, e.g. from the above mentioned WO 2019/064113, but may show problems of leaching of corrosive substances and/or unpleasant odors, e.g. when exposed to water. Further such boards show certain other disadvantages when being applied as decorative coated panel, such as floor panels, wall panels or ceiling panels, of which some have been elucidated above. WO 2019/240838 discloses a board based on MgO and MgChloride with increased chemical stability due to the addition of phosphoric acid. The present invention in the first place seeks to provide alternative boards, and methods of manufacturing such boards, wherein in accordance with several preferred embodiments a solution is obtained for problems with the boards of the state of the art. According to preferred embodiments, the invention aims at a board that can readily be used in a DPL process. Such DPL process or Direct Pressure Lamination process is a process in which one or more resin provided paper layers are cured, consolidated and adhered to a board using a heated pressing operation. Preferably, one of said resin provided paper layers is a paper layer having a print. A further one of said resin provided paper layers may be a wear layer applied on top of said print. At the side of the board opposite the print a counterbalancing layer may be applied during the same pressing operation, also including a resin-provided paper layer. The several independent aspects of the invention, as well as certain preferred embodiments thereof are contained in the claims, and further elucidated here below. In general, in accordance with any of the aspects of the invention defined below and in the claims, a MOC board is preferably obtained from a general composition comprising 18 to 40 wt%, or 18 - 26 wt% of MgO and 25 to 50 wt% or 42 - 46 wt% of MgCl2. A MOS board preferably shows a general composition comprising 18 to 40 wt% or 18 - 26 wt% of MgO and 25 to 50 wt%, or 42 - 46 wt% of MgSO4. The MgSO4, the MgCl2 respectively, may be added in a watery solution. In each of these mixtures 2 - 10 wt% of mica powder may be added. Mica powder increases the fire grading, locks water and reflects UV. As a filler 5 - 15 wt% of active carbon, 3 wt% of pigment and/or 0.25wt% of sulfate may be added. The active carbon may be used to absorb formaldehyde, for example when the obtained board is used with a melamine formaldehyde containing laminate layer. The pigments are used to give the board any desired color. Further the composition may comprise 0.25 wt% of phosphate. The phosphate prevents the board from exploding during manufacturing. In general, the MOC or MOS boards of the invention, in accordance with any of its aspects here below, may comprise any amount of plant fiber