Preparation of Dimethylolmelamine Molding Composition

To a resin kettle equipped with a mechanical stirrer and condenser are added 126.0 gm (1.0 mole) of melamine and 161.0 gm (37.2%), of formaldehyde containing 7.5% methanol by wt (2.0 moles). The mixture is heated to dissolve the melamine, and the pH is adjusted to 8.5. The solution is refluxed, and the solution is then cooled to 75°C to continue the reaction until a slightly hydrophobic condition is reached. This is detected by adding 

TABLE VIII Analytical Results for Melamine Resins and Calculated Polymer Lm Values  

Analysis on dry and true melamine-formaldehyde polymer basis  

Melamine equivalent of nitrogen, % Formaldehyde, % Condensation water/100 gm Lm 

Methylolmelamines can be prepared that are either water soluble, hydrocarbon soluble, or insoluble depending on their preparative reaction conditions. 

---