Low addition of melamine salts for improved Melamine-Urea-Formaldehyde adhesives water resistance

The addition of melamine acetate salts to an adhesive glue mix can allow the use of melamine–urea– formaldehyde (MUF) resins of lower melamine contents (rather than just urea–formaldehyde resins) and lower total amounts of melamine. Performances can be obtained that are characteristic of the top-of-the-line, generally higher mel- amine content MUF adhesive resins for the preparation of wood particleboard panels. Improvements in the panel internal-bond strength of greater than 30% can be obtained by the addition of melamine acetate salts to top-of-the-line MUF resins. The approach to the concept of increased melamine solubility with a melamine salt is compatible with the approach of increasing melamine solubility with solvents such as acetals (e.g., methylal). However, the synergy ad- vantage of using the two approaches jointly is not very marked