High pressure laminate panel and method for the production thereof

Method for the production of a high pressure laminate panel having a core layer and a polymer-coated surface layer on at least one panel surface, wherein the surface layer has as the outermost layer a polymer coating with a polyurethane(meth)acrylate polymer and wherein the method comprises the following steps:

• a) applying a coating system as a coating on a surface material for a high pressure laminate panel, wherein the coating system comprises a resin component, a hardener component, and optional additives,
• wherein the resin component is present as a mixture of components A to D, in which
• component A is a polymerizable (meth)acrylate compound having at least 2 groups with a (meth)acrylic double bond and no hydroxy groups per molecule,
• component B is a polymerizable (meth)acrylate compound having both one or more groups with a (meth)acrylic double bond as well as at least 2 hydroxy groups per molecule,
• component C is a polyurethane prepolymer having at least 2 hydroxy groups and no isocyanate groups per molecule,
• component D is a resin with an aminoplast structure having at least 2 hydroxy groups per molecule;
• and wherein the hardener component is an at least difunctional isocyanate;
• and
• b) drying the surface material coated in step a) at an elevated temperature at which a reaction takes place between the hydroxy groups in the resin component and the isocyanate groups of the hardener component so that a polyurethane polymer is formed in the coating which comprises groups with a (meth)acrylic double bond;
• c) providing a laminate stack comprising a material for the formation of a core layer of a high pressure laminate panel, said material comprising one or more layers of a carrier material impregnated with a curable synthetic resin, and comprising the coated surface material obtained in step b) as a surface layer so that at least on one side of the laminate stack the surface material obtained in step b) forms the outermost layer, and the dried coating is present on at least one surface of the laminate stack;
• d) pressing the laminate stack at increased pressure and at a temperature above the drying temperature of step b) so that a polymerization of the (meth)acrylic double bonds in the dried coating takes place and a high pressure laminate panel with a core layer and a surface layer on at least one panel surface is formed which as the outermost layer has a polymer coating with a polyurethane(meth)acrylate polymer.