Hardening composition for the hardening of an urea-formaldehyde adhesive, and its use in the glueing of chipboard

摘要

The hardener composition for urea-formaldehyde resins which may contain up to 20 % by weight of melamine and up to 5 % by weight of phenol, each percentage being based on the total weight of the resin, contains (a) an ammonium salt of an inorganic or organic acid, (b) an acid which does not react with the hardener composition, (c) urea, and optionally (d) a metal salt, an aqueous solution of the hardener composition having a pH 2 but may also have a pH 2 if the hardener composition contains a glycol or a functional derivative thereof.