| 摘要 |
<p>A curing agent for curing formaldehyde-containing resins comprises (i) an ammonium salt and (ii) a Group II or Group III metal, or zinc or iron, salt and is used for curing resins having a ratio of formaldehyde to comonomer of no more than about 1.1:1. The combination of an ammonium and an aluminium salt is preferred and, when sulphate ions are present, can be used as a suitably concentrated, stable aqueous batch by including urea in the solution to improve the solubility of ammonium aluminium sulphate. The curing agent may be used to produce resin-bonded products such as moulded chipboard.</p> |
