Coating compositions

A process for inhibiting fouling of a substrate in a fouling environment, which comprises applying to the substrate, before exposure to the said environment, an anti-corrosive primer coating and thereafter, an anti-fouling composition which comprises:

• (A) a polymer carrying pendant and/or terminal curable functional groups, at least a major proportion of the repeating units in the polymer of (A) being other than siloxane units, and
• (B) a curable organohydrogen polysiloxane or polydiorganosiloxane, the curable functional groups in component (A) being capable of undergoing a curing reaction with component (B),
• and curing the applied composition, wherein the concentration of the siloxane component (B) progressively increases from the substrate to the outer regions of the coating thereby presenting a siloxane-rich surface layer to the fouling environment.

A substrate in a fouling environment bearing a cured coating formed from a composition which comprises:

• (A) a polymer carrying pendant and/or terminal curable functional groups, at least a major proportion of the repeating units in the polymer of (A) being other than siloxane units, and
• (B) a curable organohydrogen polysiloxane or polydiorganosiloxane, the curable functional groups in component (A) being capable of undergoing a curing reaction with component (B),
• wherein the concentration of the siloxane component (B) progressively increases from the substrate to the outer regions of the coating thereby presenting a siloxane-rich surface layer to the fouling environment and the coating renders substrate resistant to fouling.