<b>Marine Coatings</b>
Biofouling is the name given to unwanted colonization by microorganisms - and is not only dangerous for involuntary divers: the growth damages the rudder and the ship's hull. Because depending on the sailing area, up to 150 kilograms of vegetation per square meter can settle on the lower ships. This not only has extreme effects on weight. Fouling increases frictional resistance. Up to 40 percent more fuel is needed to bring an overgrown ship up to the same speed.
In modern shipping, attempts are made to cope with the matter with complex chemical coatings: initially only in the form of lead-based anti-rust agents and marine paint. However, effective antifouling paints have been used since the 1950s, which use metal-containing compounds to kill the growth.
As an alternative to this, biocide-free, so-called fouling-release coatings have been available since 1999, which shake off stowaways with extremely smooth surfaces.
Since 2008, the broad spectrum biocide tributyltin hydride (TBT) has been banned worldwide by a regulation of the International Maritime Organization (IMO). This tin-containing antifouling paint is very toxic and triggers irreversible hormonal disorders in marine organisms - which can lead to species extinction.
After the international ban on tin-containing antifouling coatings, the industry is looking for alternatives that are as effective and as biocide-free as possible. Because antifoulings pollute the environment - and more stringent requirements are foreseeable. In addition to the ecological requirements, economic aspects are also becoming increasingly noticeable:
In recent years it has been shown that some antifoulings release too many biocides because the paint wears off too quickly. Non-stick coatings last longer, but haven't been quite as efficient until now.