3. Paints as conventional organic coating systems for
corrosion protection
Paints confer two main attributes: decoration and protective
ability. The former aspect can be achieved by various strategies
like include pigments in the formulation to provide the
desired colour, hiding and optical properties.However, the major
developments in commercially available organic coatings are
related with the protection imparted to the underneath surface.
Taking into account that about one-third of the total output of
metal is eliminated from technical consumption by corrosion,
the effort devoted to retard the corrosion reactions is fully justified.
In marine paints this is usually achieved by combining
the effects of both the addition of anticorrosive pigments to
the formulation (electrochemical protection) and the formation
of stable and strongly adherent coating layers on the substrate
(barrier protection). These two mechanisms do not act separately,
even although depending on the paint composition one
prevails.