Alkaline copper quaternary, usually abbreviated ACQ, is a type of water-based wood preservative product containing a soluble copper(II) complex and quaternary ammonium alkyl- or aryl-substituted compounds ("quats"). Thus the product was originally called ammoniacal copper/quaternary ammonium.
- 1 Composition
- 2 Mechanism of action
- 3 Use
- 4 Safety
- 5 History
- 6 See also
- 7 References
- 8 External links
The copper in the preparation is in the form of a soluble complex with ammonia NH
3 or an amine such as ethanolamine N(C
2). In any case, the copper content is usually expressed as a weight percentage of the amount of copper oxide CuO that would account for the copper present.
As a copper carrier, ammonia has the advantage that it will penetrate difficult-to-treat Western species better than other waterborne preservatives. Otherwise ethanolamine is preferred as copper carrier.
Quaternary ammonium cations
The quaternary ammonium cation in some formulations is didecyldimethylammonium (DDA) N+(CH
DDA carbonate is non-volatile and highly soluble in water, with near zero octanol-water partition coefficient.
Another quaternary ammonium cation used in some formulations is alkyldimethylbenzylammonium (ADBA). The formula is N+(CH
2n+1), where n varies between 8 and 18.