METHOD FOR COATING WOOD-BASED MATERIALS WITHOUT ABRADING THE SURFACE

Abstract

The present invention relates to a new and improved method for coating wood-based materials, which comprises treating the surface of a wood-based material with 0.05 to 50 g/m.sup.2, preferably 0.1 to 20 g/m.sup.2, more preferably 0.3 to 10 g/m.sup.2 of a surface-active substance, preferably as 0.1 to 60 wt %, preferably 0.5 to 50 wt %, more preferably 1 to 40 wt %, more particularly 2.5 to 30 wt % solutions, more particularly a solution of a surfactant.

Claims

1.-17. (canceled)

18. A method for coating wood-based materials, which comprises treating the surface of a wood-based material with 0.05 to 50 g/m.sup.2 of a surface-active substance, placing solutions composed of solvents and the surface-active substance, and coating the wood-based materials with decorative papers.

19. The method for coating wood-based materials according to claim 18, wherein the surface of the wood-based material is treated with a surface-active substance, without partial abrading of the wood-based material.

20. The method for coating wood-based materials according to claim 18, wherein the surface of the wood-based material is treated with 0.1 to 20 g/m.sup.2 of the surface-active substance.

21. The method for coating wood-based materials according to claim 18, wherein the surface of the wood-based material is treated with 0.3 to 10 g/m.sup.2 of the surface-active substance.

22. The method for coating wood-based materials according to claim 18, wherein the surface-active substance is used as a 0.1 to 60 wt % solution.

23. The method for coating wood-based materials according to claim 18, wherein the surface-active substance is used as a 0.5 to 50 wt % solution.

24. The method for coating wood-based materials according to claim 18, wherein the surface-active substance is used as a 1 to 40 wt % solution.

25. The method for coating wood-based materials according to claim 18, wherein the surface-active substance is used as a 2.5 to 30 wt % solution.

26. The method for coating wood-based materials according to claim 18, wherein the surface-active substance is used 1 to 40 wt % solution.

27. The method for coating wood-based materials according to claim 18, wherein the surface-active substance is a surfactant.

28. The method for coating wood-based materials according to claim 27, wherein said surfactant used comprises anionic, cationic, nonionic, amphoteric surfactants or mixtures thereof.

29. The method for coating wood-based materials according to claim 28, wherein said anionic surfactants used comprise alkali metal, alkaline earth metal or ammonium sulfates, sulfates of branched or unbranched fatty alcohols or oxo-process alcohols, branched or unbranched fatty alcohol alkoxylates or oxo-process alcohol alkoxylates, fatty alcohol ether sulfates having branched or unbranched C.sub.8-C.sub.20 alkyl chains and 2 to 50 ethylene oxide (EO) units, sulfates of fatty acids and oils, ethoxylated alkylphenol sulfates, alcohol sulfates, sulfates of ethoxylated alcohols or fatty acid esters, sulfates of naphthyl alcohol or ethoxylated naphthyl alcohol, sulfates of arylalkyl alcohols or arylalkyl ethoxylates, alkali metal, alkaline earth metal or ammonium sulfonates, sulfonates of fatty acids and oils, sulfonates of ethoxylated alkylphenols, sulfonates of alkoxylated arylphenols, naphthalenesulfonate condensates, dodecyl- and tridecylbenzenesulfonates, naphthalene- and sikylnaphthalenesulfonates or sulfosuccinates, sulfonates of branched or unbranched fatty alcohols or oxo-process alcohols, sulfonates of branched or unbranched fatty alcohol alkoxylates or oxo-process alcohol alkoxylates, sulfonates of fatty acids and oils, ethoxylated alkylphenol sulfonates, alcohol sulfonates, sulfonates of ethoxylated alcohols or fatty acid esters, sulfonates of naphthyl alcohol or ethoxylated naphthyl alcohol, sulfonates of arylalkyl alcohols or arylalkyl ethoxylates, phosphates of branched or unbranched fatty alcohols or oxo-process alcohols, phosphates of branched or unbranched fatty alcohol alkoxylates or oxo-process alcohol alkoxylates, phosphates of fatty acids and oils, ethoxylated alkylphenol phosphates, alcohol phosphates, phosphates of ethoxylated alcohols or fatty acid esters, phosphates of naphthyl alcohol or ethoxylated naphthyl alcohol, phosphates of arylalkyl alcohols or arylalkyl ethoxylates, or mixtures thereof.

30. The method for coating wood-based materials according to claim 29, wherein said alkali metal, alkaline earth metal or ammonium sulfates used comprise such as ammonium sulfate, lithium sulfate, sodium sulfate, potassium sulfate, calcium sulfate, magnesium sulfate, strontium sulfate, lithium hydrogensulfate, sodium hydrogensulfate, potassium hydrogensulfate, calcium hydrogensulfate, magnesium hydrogensulfate, strontium hydrogensulfate, preferably sodium sulfate, potassium sulfate, calcium sulfate, magnesium sulfate, sodium hydrogensulfate, potassium hydrogensulfate, calcium hydrogensulfate, magnesium hydrogensulfate, preferably sodium sulfate, potassium sulfate, calcium sulfate and magnesium sulfate, more particularly sodium sulfate and ammonium sulfate, or mixtures thereof.

31. The method for coating wood-based materials according to claim 28, wherein said surfactant used comprises C.sub.12 alkyl sulfate, Na salt.

32. The method for coating wood-based materials according to claim 28, wherein said surfactant used comprises isononyl-PO/EO-OH.

33. A coated wood-based material obtained by the process according to claim 18.

34. A decorative wood-based material board comprising the coated wood-based material according to claim 33.

Description

EXAMPLES

Examples 1 to 8

[0060] Commercial unsanded 19 mm P2 chipboard (emission class E1) [examples 1 to 8] were used.

[0061] Surfactants: [0062] SDS: Sulfopon 12 G=C.sub.12 alkyl sulfate, Na salt, anionic surfactant [0063] KP933: Kauropal 933=isononyl-PO/EO-OH, nonionic surfactant

[0064] The results can be seen in table 1.

Comparative Examples C1 and C2

[0065] Commercial unsanded 19 mm P2 chipboard (emission class E1) were used.

[0066] The results can be seen in table 1.

[0067] Testing of coatability by droplet holdout time:

[0068] As a measure of the coatability, the holdout time of a water droplet or the curative droplet was employed: Using a pipette, a liquid droplet of defined volume was applied to the surface of the wood-based material and a determination was made of the time taken for the liquid to be taken completely into the WBM surface. The longer the droplet holdout time, the poorer the coatability.

[0069] Coating materials:

[0070] The wood-based material boards were coated as follows with decorative papers. [0071] MFC: coating of the wood-based material boards with melamine-resin-impregnated decorative papers. [0072] Foil: coating of the wood-based material boards with curative primer, surface glue and urea-resin-impregnated decorative papers.

[0073] Materials testing of the coating: [0074] CCT=cross-cut test: [0075] Using a cutter blade, a diamond-shape pattern of cuts was produced on the surface (spacing of the individual cuts about 1 to 2 mm). In the case of poor adhesion, the surface coating flakes off, particularly in the acute-angle corners of the diamonds. The result was evaluated according to a simplified school-grade system: 1no flakes, 2a few flakes, 3many flakes [0076] T=tearing: [0077] After coating had been carried out, an overhang of paper was pulled vertically to the surface of the chipboard. From the nature of the tear, a conclusion was drawn about the quality of the adhesion (evaluated: good=tear took place directly at the edge; moderate=paper tears off partly at the edge and is partly detached again from the board; poor: foil is easily detached from the surface).

TABLE-US-00001 TABLE 1 Droplet holdout Example Board Amount of time Coating Materials Adhesion No. type Surfactant surfactant [min] material testing value 1 Chip KP933 0.5 g/m.sup.2 24 MFC CCT 1 2 Chip KP933 0.5 g/m.sup.2 24 Foil T good 3 Chip KP933 1 g/m.sup.2 17 MFC CCT 1 4 Chip KP933 1 g/m.sup.2 17 Foil T good 5 Chip SDS 1 g/m.sup.2 9 MFC CCT 1 6 Chip SDS 1 g/m.sup.2 9 Foil T good 7 Chip SDS 2 g/m.sup.2 1 MFC CCT 1-2 8 Chip SDS 2 g/m.sup.2 1 Foil T moderate C1 Chip >60 MFC T 2-3 C2 Chip >60 Foil CCT poor