Patent No. U.S. 6,559,202 B1
Akzo Nobel has received a patent for an antifouling paint having a binder comprising a rosin material and an auxiliary film-forming resin. The paint contains an ingredient with marine biocide properties, wherein the binder comprises a blend of the rosin material and an auxiliary film-forming resin in a ratio of 20:80 to 95:5 by weight, the auxiliary film-forming resin comprising 20-100% by weight of an acid-functional film-forming polymer whose acid groups are blocked by groups capable of hydrolyzing or dissociating to leave a polymer soluble in sea water, the blocking groups being selected from divalent metal atoms bonded to a monovalent organic residue, divalent metal atoms bonded to a hydroxyl residue and monoamine groups which form an organic solvent soluble amine salt of the polymer, and 80% to zero percent by weight of a non-hydrolyzing water-insoluble film-forming polymer.