| 摘要 |
<p>Hardeners for powder lacquer systems are mfd. from monosalts of aromatic polycarboxylic acids having at least three carboxyl gps., and 2-phenyldiimidazoline, by introducing the acid as an anhydride that is hydrolised in the presence of a 2-4C alcohol in water. After this the 2-phenyldiimidazoline (delta 2) is added as a solid to the aq. suspension or acid soln. and the precipitated monosalt is removed. Pref. an alcohol concn. of 3-15 wt.% and more specifically of 5-10 wt.% w.r.t. the wt. of the polycarboxylic acid anhydride, is present in the water during hydrolysis. The result is only obtd. when the anhydride is used as the starting material and the alcohol is added only during hydrolysis of the anhydride into an acid. Suitable alcohols are ethanol, n-propanol, isopropanol, sec. butanol, ethylene glycol, etc.. Lustreless coatings which exhibit excellent mechanical properties such as those traditionally obtd. using poisonous or inflammable liqs. as solvents are produced using water as a solvent.</p> |
