MELAMINE-REINFORCED UF GLUES CONTAINING UP TO 0.9 OF MELAMINE FOR THE PRODUCTION OF MEDIUM-DENSITY FIBERBOARDS

摘要

The invention relates to a method for producing melamine-urea-formaldehyde resins containing up to 0.9% of melamine by reacting a) urea containing 0 to 10 wt% of one or more compounds A, together with formaldehyde and melamine, in the presence of a base at a pH value of 7.5 to 11, a temperature of 20 to 120°C, and a pressure of 0.1 to 10 bar, b) then carrying out the reaction in the presence of an acid optionally containing urea that comprises 0 to 10 wt% of one or more compounds A, at a temperature of 60 to 180°C and a pressure of 0.1 to 10 bar, and c) then adding urea containing 0 to 10 wt% of one or more compounds A, stage b) being carried out at a pH value of 4 to 5.9.