METHOD FOR PRODUCING A LAMINATE

• US 20100307675A1
• Filed: 12/22/2008
• Published: 12/09/2010
• Est. Priority Date: 12/21/2007
• Status: Active Grant

• Current Assignee: Surface Technologies GmbH & Co. KG
• Original Assignee: Surface Technologies GmbH & Co. KG
• Inventors: Buhlmann, Carsten
• Granted Patent: US 8,366,854 B2
• Time in Patent Office: Days
• US Class Current: 156/272.2
• CPC Class Codes: B32B 2038/0076 Curing, vulcanising, cross-linking
• CPC Class Codes: B32B 2317/125 impregnated with thermosetting resin
• CPC Class Codes: B32B 2317/16 Wood, e.g. woodboard, fibreboard, woodchips
• CPC Class Codes: B32B 38/164 Drying
• CPC Class Codes: B44C 3/02 Superimposing layers B44C3/005 takes precedence
• CPC Class Codes: B44C 5/043 containing wooden elements
• CPC Class Codes: D21H 27/26 characterised by the overlay sheet or the top layers of the structures decorative panels B44C5/04; wood grain effects B44F9/02
• CPC Class Codes: D21H 27/28 treated to obtain specific resistance properties, e.g. against wear or weather water-repelling agents D21H21/16

Abstract

The invention relates to a method for producing a decorated laminate having a plate-shaped core made of wood or wood material, a decorative layer on at least one side of the core, and a cover layer made of aminoplast on the decorative layer, comprising the following steps: attaching the decorative layer, applying a layer made of an aqueous solution of an aminoplast precursor to form a cover layer on the decorative layer, at least partially drying the cover layer, curing the aminoplast under pressure and heat, wherein a part of said solution of said aminoplast precursor is initially applied and the partial layer thus generated is dried and said step is repeated at least twice, in order to form the final cover layer.

Claims

1. A process for producing a decorated laminate comprising a plateshaped core of wood or wood material, a decorative layer on at least one side of the core and a cover layer of aminoplast on the decorative layer, including the steps:

applying the decorative layer,

applying a layer of an aqueous solution of an aminoplast precursor for forming a cover layer on the decorative layer,

at least partially drying the cover layer, and

hardening the aminoplast under pressure and heat, characterised in that firstly a part of the solution of the aminoplast precursor is applied and the sublayer produced in that way is initially dried and said step is repeated at least twice to form the definitive cover layer.

2. A process according to claim 1 wherein initial drying of the sublayers is effected with IR radiation and/or hot air.

3. A process according to claim 2 wherein the aminoplast is a melamine-formaldehyde resin.

4. A process according to claim 3 wherein an aqueous solution of the aminoplast with more than 60 percent by weight of solid material is used.

5. A process according to claim 4 wherein the applied sublayers are dried in each case to more than 80 percent by weight of solid material.

6. A process according to claim 5 wherein the viscosity of the solution of the aminoplast is 100 to 200 mPas.

7. A process according to claim 6 wherein the viscosity of the sublayers rises with the layer sequence.

8. A process according to claim 7 wherein particles of a hard solid material are applied at least with the first applied sublayer.

9. A process according to claim 8 wherein the particles of the hard solid material are dispersed in the solution for the first sublayer.

10. A process according to claim 8 wherein the particles of the hard solid material are scattered on the first sublayer prior to initial drying.

11. A process according to claim 10 wherein the hard solid material is selected from aluminium oxide, silicon dioxide, silicon carbide and boron nitride.

12. A process according to claim 11 wherein the mean particle size of the hard solid material is 180 to 220 ˜

m.

13. A process according to claim 12 wherein the thickness of the first sublayer is less than the mean particle size of the hard solid material while the thickness of the overall cover layer is greater than said particle size.

14. A process according to claim 13 wherein nanoparticles are incorporated at least in the last sublayer.

15. A process according to claim 14 wherein nanoparticles comprise aluminium oxide or silicon dioxide.

16. A process according to claim 15 wherein the nanoparticles are of a size of 5 to 100 nm.

17. A process according to claim 16 which to apply the decorative layer to the plate-shaped core a layer of liquid glue is applied and a decorative paper is placed thereon.

18. A process according to claim 16 which to apply the decorative layer to the plate-shaped core a one-coloured paper is glued on, which is printed upon with the decoration prior to application of the cover layer.

19. A process according to claim 18 wherein a urea-formaldehyde glue is used for gluing on the decorative paper or one-coloured paper.

20. A process according to claim 18 wherein a direct or indirect intaglio printing, flexoprinting, offset printing or digital printing method is used for the printing operation.

21. A process according to claim 20 wherein printing is effected by means of inkjet printing.

22. A process according to claim 21 wherein a stabilising layer is applied simultaneously with the application of the decorative layer and the application of the cover layer on the side of the plate-shaped core opposite to the decorative layer.

23. A process according to claim 22 wherein the stabilising layer is formed from a plurality of sublayers of an aminoplast which are respectively initially dried prior to application of the next sublayer.

24. A process according to claim 23 wherein the sublayers of the stabilising layer are applied simultaneously with the sublayers of the cover layer and initially dried.

25. A process according to claim 24 wherein a paper layer is applied prior to application of the stabilising layer on the side of the plate-shaped core, that is opposite to the decorative layer.