Wooden composite board with antistatic properties

Abstract

A wood-based panel includes at least one carrier board and at least one resin layer disposed side of the board. The at least one resin layer includes carbon-based particles, at least one compound of the formula R.sup.1.sub.aR.sup.2.sub.bSiX.sub.(4-a-b), and/or hydrolysis products. X is H, OH, or a hydrolysable moiety selected from the group including halogen, alkoxy, carboxyl, amino, monoalkylamino or dialkylamino, aryloxy, acyloxy, and alkylcarbonyl. R.sup.1 is an organic residue selected from the group including alkyl, aryl, and cycloalkyl, which may be interrupted by —O— or —NH—. R.sup.1 has at least one functional group Q.sub.1 selected from a group containing a hydroxy-, amino, monoalkylamino, carboxy, mercapto, alkoxy, aldehyde, acrylic, acryloxy, methacrylic, methacryloxy, cyano, isocyano and epoxide group, R.sup.2 is a non-hydrolyzable organic moiety selected from the group including alkyl, aryl, alkenyl, alkynyl, cycloalkyl, and cycloalkenyl; A is 0, 1, 2, or 3. B is 1, 2, 3, or 4.

Claims

1. A wood-based panel having antistatic properties comprising at least one carrier board and at least one resin layer disposed on at least one side of the at least one carrier board, wherein the at least one resin layer consists of: aqueous formaldehyde containing resin(s); carbon-based particles; at least one compound having the general formula (Ia):
R.sup.1.sub.aSiX.sub.(4-a)  (Ia), and/or hydrolysis products thereof, wherein X is H, OH, or a hydrolyzable moiety selected from the group comprising halogen, alkoxy, carboxy, amino, monoalkylamino or dialkylamino, aryloxy, acyloxy, and alkylcarbonyl, wherein R.sup.1 is an organic moiety selected from the group comprising alkyl, aryl, C.sub.2-C.sub.6 alkenyl, C.sub.3-C.sub.8 cycloalkenyl, and cycloalkyl, which may be interrupted by —O— or —NH—, wherein R.sup.1 has at least one functional group Q.sub.1 selected from a group comprising a hydroxy, amino, monoalkylamino, carboxy, mercapto, alkoxy, aldehyde, acrylic, acryloxy, methacrylic, methacryloxy, cyano, isocyano and epoxy group, and at least one further compound of the general formula (II):
R.sup.3.sub.c,SiX.sub.(4-c)  (II), and/or hydrolysis products thereof, wherein X has the above meaning, wherein R.sup.3 is a non-hydrolyzable organic moiety selected from the group comprising alkyl, aryl, alkenyl, alkynyl, cycloalkyl, and cycloalkenyl, and wherein c is 1, 2, 3, or 4.

2. The wood-based panel according to claim 1, wherein X is selected from a group comprising H, OH, fluorine, chlorine, bromine, iodine, C.sub.1-6 alkoxy, C.sub.6-10 aryloxy, C.sub.2-7 acyloxy, and C.sub.2-7 alkylcarbonyl.

3. The wood-based panel according to claim 1, wherein R.sup.1 is selected from a group comprising C.sub.1-C.sub.30 alkyl, C.sub.2-C.sub.6 alkenyl, C.sub.3-C.sub.8 cycloalkyl, and C.sub.3-C.sub.8 cycloalkenyl.

4. The wood-based panel according to claim 1, wherein the at least one functional group Q.sup.1 is selected from a group comprising epoxy, hydroxy, ether, acrylic, acryloxy, methacrylic, methacryloxy, amino, alkoxy, cyano, and isocyano groups.

5. The wood-based panel according to claim 1, wherein the non-hydrolyzable organic moiety R.sup.3 is selected from a group comprising C.sub.1-C.sub.15 alkyl, C.sub.2-C.sub.6 alkenyl, C.sub.2-C.sub.6 alkynyl, and C.sub.6-C.sub.10 aryl.

6. The wood-based panel according to claim 1, wherein at least one layer of a color base coat is provided on the at least one resin layer containing at least one carbon-based particle.

7. The wood-based panel according to claim 6, wherein at least one primer layer is provided on the at least one resin layer and the at least one color base coat layer.

8. The wood-based panel according to claim 1, comprising at least one decorative layer.

9. The wood-based panel according to claim 8, comprising at least one resin protective layer provided on the at least one decorative layer.

10. The wood-based panel according to claim 9, wherein a second resin layer is applied to the at least one resin protective layer.

11. The wood-based panel according to claim 10, wherein at least one layer of abrasion-resistant particles is applied to the second resin layer on the upper side of the wood-based panel.

12. The wood-based panel according to claim 11, wherein at least one layer of a further resin layer is provided on the at least one layer of abrasion-resistant particles.

13. A method of producing the wood-based panel according to claim 1, comprising the steps of providing a resin suspension based on a formaldehyde containing resin comprising carbon-based particles, at least one compound of the general formula (Ia), and at least one further compound of the general formula (II); applying the resin suspension as a resin layer to an upper side of the at least one carrier board; applying at least one layer of a color base coat layer; applying at least one primer layer; applying at least one decorative layer; applying at least one protective resin layer; and pressing the layer structure in a short cycle press.

14. The method according to claim 13, comprising the steps of: applying at least one second resin layer to the at least one protective resin layer on the upper side of the at least one carrier board and a parallel application of a resin layer to an underside of the at least one carrier board as a backing; scattering of at least one layer of abrasion-resistant particles on the upper side of the carrier board; applying at least one layer of a further resin layer to the at least one layer of abrasion-resistant particles on the upper side of the carrier board; and pressing the layer structure.

15. The wood-based panel of claim 1, wherein the carbon-based particles are carbon nanotubes (CNT) or graphene.

16. The method of claim 13, comprising the step of placing a backing paper on an underside of the at least one carrier board.

17. The method of claim 14, comprising the step of applying a further resin layer to the underside of the at least one carrier board as a backing parallel with the step of applying the at least one layer of a further resin layer to the at least one layer of abrasion-resistant particles on the upper side of the carrier board.

18. The method of claim 14, comprising the step of placing a backing paper on the underside of the at least one carrier board as a backing.

19. The method of claim 17, comprising the step of placing a backing paper on the underside of the at least one carrier board as a backing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic diagram of a wood-based panel according to a first embodiment of the invention; and

(2) FIG. 2 schematic representation of a wood-based panel according to a second embodiment.

DESCRIPTION OF THE INVENTION

(3) FIG. 1 shows a cross-section of a first embodiment of the present wood-based panel with the following layer structure (seen from bottom to top): backing of backing-layer paper 11-wood-based carrier board 1-colorless base coat layer with silane-modified carbon particles 2-color base coat layer 3-primer layer 4-print decor layer 5-resin protection layer with glass beads 6-optional overlay layer 7 (not shown).

(4) FIG. 2 shows the cross-section of a second embodiment of the present wood-based panel with the following layer structure (seen from bottom to top): Backing of backing paper 11-backing of several layers of a resin layer 11a, 11b-wood-based carrier board 1-colorless base coat layer with silane-modified carbon particles 2-color base coat layer 3-primer layer 4-print decor layer 5-resin protection layer with glass beads 6-resin layer 8-layer of abrasion-resistant particles 9-several layers of a resin layer (with glass bead in at least one layer) 10.

Example 1: Preparation of a First Resin Suspension with Modified Carbon Particles

(5) For modification, 90 g (or 80 g) of melamine-formaldehyde resin and 8.5 g (or 17 g) of water are added, followed by 0.08 g (or 0.16 g) of para-toluenesulphonic acid. To this aqueous solution 0.7 g (or 1.4 g) of gylcidyloxypropyltriethoxysilane and 0.16 g (or 0.32 g) of ocytyltriethoxysilane are added.

(6) Then 1.5 g (or 3 g) of CNTs are dispersed in the solution using ultrasound and high shear (15 000 rpm ultraturray) and stirred at 40° C. for 30 minutes. This solution can now be processed like a normal resin system. (In parentheses are the specifications for the sample with 3% CNT in the resin)

Example 2: Preparation of a Second Resin Suspension with Modified Carbon Particles

(7) For modification, 98.5 g water is added and then 0.08 g para-toluenesulfonic acid. To this aqueous solution 0.7 g of gylcidyloxypropyltriethoxysilane and 0.16 g of ocytyltriethoxysilane are added.

(8) Subsequently, 1.5 g CNTs are dispersed in the solution using ultrasound and high shear forces (15 000 rpm ultraturray) and stirred at 40° C. for 30 minutes. This purely aqueous solution can now be added to melamine resin directly at the application machine.

Example 3: Production of a First Wood-Based Panel According to FIG. 1

(9) A melamine resin is applied to an HDF (8 mm) with a roller as a colorless base coat, which contains 1.5% by weight carbon nanotubes. The nanotubes had a length of about 5 μm and a diameter of 1.2 to 2.0 nm. The solids content of the fleet was about 60% by weight. The melamine resin contained the usual additives (hardeners, defoamers, wetting agents etc.). The melamine resin is dried in a circulating air dryer to a moisture content of 10 to 15%.

(10) Afterwards, a colored base coat is applied to the colorless base coat layer. This consists of titanium dioxide and casein as a binding agent. A quantity of approx. 5 g color base coat/m.sup.2 is alternately applied with subsequent intermediate drying in a circulating air dryer. This is repeated up to five times.

(11) Then a primer is applied in liquid form in a quantity of approx. 10 g/m.sup.2 and dried (circulating air dryer). A decor is then applied using either indirect gravure or digital printing. Drying takes place again in the circulating air dryer.

(12) This is followed by the application of a protective layer consisting of melamine resin (65% by weight, with the usual additives) and glass beads (diameter: approx. 90 μm, approx. 20% by weight). Here, too, drying takes place in a circulating air dryer.

(13) The coated HDF is then pressed on a short-cycle press with a backing and a corundum-containing overlay impregnate at high pressure (50 kp/cm.sup.2) and high temperature (200° C.) for approx. 10 seconds. After cooling and subsequent air conditioning (50% rel. LF, 23° C.) the surface resistance was determined on the sample in accordance with DIN EN 1081: 2018. This resulted in a value of 1.0×10.sup.9Ω. A value of 5×10.sup.12Ω was found in a zero sample without carbon nanotubes. When testing various surface properties (behavior to water vapor, surface hardening by means of an acid test), no abnormalities were found.

Example 4: Production of a Second Wood-Based Panel as Shown in FIG. 2

(14) On a HDF (8 mm), a melamine resin is applied with a roller as a colorless base coat, which contains approx. 3% by weight carbon nanotubes. The solids content of the fleet was about 60% by weight. The melamine resin contained the usual additives (hardeners, defoamers, wetting agents etc.). The melamine resin is dried in a circulating air dryer to a moisture content of 10 to 15%.

(15) Afterwards, a colored base coat is applied to the colorless base coat layer primer. This consists of titanium dioxide and casein as a binding agent. A quantity of approx. 5 g color base coat/m.sup.2 is alternately applied with subsequent intermediate drying in a circulating air dryer. This is repeated up to five times.

(16) Then a primer is applied in liquid form in a quantity of approx. 10 g/m.sup.2 and dried (circulating air dryer). A decor is then applied using either indirect gravure or digital printing. Drying takes place again in the circulating air dryer. This is followed by the application of a protective layer consisting of melamine resin (65% by weight, with the usual additives) and glass beads (diameter: approx. 90 μm, approx. 20% by weight). Here, too, drying takes place in a circulating air dryer. The boards were then coated in a coating line, first on the printed top side in a roller application unit with approx. 50 g melamine resin (approx. 65 wt. % with the corresponding auxiliary materials). At the same time, approximately the same amount of melamine resin (approx. 65% by weight with the appropriate additives and colored brown) was applied to the underside of the board.

(17) Afterwards, approx. 20 g corundum/m.sup.2 (F 200) is scattered on the upper side with a scattering device (Sandvik). The melamine resin is dried in a circulating air dryer. Then three more applications of 20 g melamine resin each (approx. 65% by weight with the corresponding auxiliary materials and approx. 20% by weight of glass beads) are applied and intermediately dried in a circulating air dryer. The same is done with the colored melamine resin without glass beads.

(18) The coated HDF is then pressed on a short-cycle press with a backing and an overlay at high pressure (50 kp/cm.sup.2) and high temperature (200° C.) for about 10 seconds. After cooling and subsequent air conditioning (50% rel. LF, 23° C.), a surface resistance was determined on a sample according to DIN EN 1081: 2018. This resulted in a value of 9.0×10.sup.8Ω. With a zero sample a value of 3×10.sup.12Ω was found. When testing various surface properties (behavior to water vapor, surface hardening by means of an acid test), no abnormalities were found.