Patent ID: 7235303
Filing Date: 2007-06-26
Classification: B32B,C08G,D21H,Y10T

Abstract:
1. A phenol-free decorative laminate sheet comprising multilayer carrier materials which are impregnated with binders, bonded and cured, wherein the impregnating resin used is a urea/melamine/formaldehyde resin which was processed exclusively in an aqueous reaction medium and to which a polymer dispersion was added, a precondensate of urea, melamine and formaldehyde having been prepared for the impregnating resin in a first stage in the presence of a first reactive catalyst in the pH range from 7.0 to 8.5 in a temperature range from 75° C. to 95° C. and, in a second stage, an acidic second catalyst, together with urea, melamine and an aqueous polymer dispersion, having been added to the precondensate in the pH range from 4.0 to 6.0 and at a temperature of from 75° C. to 95° C. and, after the end of the reaction time, the prepared impregnating resin having been adjusted to a pH of from 8.0 to 8.5 by adding alkali; and the polymer dispersion used is one or more of acrylate, methacrylate, vinyl acetate homopolymers. styrene/acrylate, styrene/methacrylate, or polybutadiene/styrene copolymers in amounts of from 0.5% mass to 10% mass.