Manufacturing method of E0 grade Melamine-Urea-Formaldehyde Resin(MUF) and adhesive for medium density fiber board by use of MDF Resin

摘要

PURPOSE: A method for preparing a melamine-urea-formaldehyde resin and an adhesive for medium density fiberboard(MDF) using the resin are provided, to reduce the amount of the unreacted formaldehyde contained in the resin and the discharging amount of formaldehyde of MDF remarkably, and to improve the physical properties of MDF. CONSTITUTION: The method comprises the steps of polycondensing 0-10 wt% of melamine and formaldehyde(wherein the molar ratio of formaldehyde to an amino group is 1.3-2.2) at a pH 7.3-9.0 at a temperature of 80-95 deg.C; adding urea to the obtained one in the molar ratio of formaldehyde to an amino acid of 0.75-0.9 and polycondensing the mixture at a pH of 6.8-7.8 and at a temperature of 80-95 deg.C; adding an acidic catalyst to the product to make the pH be 4.0-6.8; adding an alkali catalyst to the product to neutralize the solution by making the pH be 6.0-8.0; adding urea to the obtained product in the molar ratio of formaldehyde to an amino acid of 0.53-0.62 and polycondensing the mixture; and adding urea to the obtained product in the molar ratio of formaldehyde to an amino acid of 0.38-0.46 and polycondensing the mixture, and aging it for 1-6 hours.