Urea—formaldehyde (UF) resins are based on the manifold
reaction of two monomers, urea and formaldehyde.
By using different conditions of reaction and preparation
a more or less innumerable variety of condensed structures
is possible. UF resins are the most important type
of the so-called aminoplastic resins. Currently, approximately
6 billion tons are produced per annum worldwide,
based on a usual solids content of 66% by mass.