Method and the composition, in order to reduce the fouling by the marine organisms, animal or vegetable origin, of metal structures, such as hulls of ships, immersed in sea water.

摘要

852,882. Preventing fouling by marine growths. HUGHES & CO. Ltd., F. A. Dec. 12, 1958 [Jan. 3, 1958(2)], Nos. 265/58 and 266/58. Class 123(1) The fouling of structures, especially ships' hulls, immersed in sea water by marine growths is prevented by discharging against the underwater surface a growth deterrent consisting of a substantially insoluble liquid which may itself have a growth deterrent effect and/or in which is dissolved or dispersed a deterrent substance, the liquid containing from 0À05 to 0À4% by weight of a wetting agent, which may itself be toxic to marine growths, to improve the ability of the liquid to wet the underwater surface. Suitable carrier liquids are kerosene and light diesel oils whilst the compounds which can be dissolved or dispersed therein are solid metals or metal compounds such as the oxides of copper, arsenic or mercury and organic compounds such as 2:4 di-isobutyl phenol, phenyl mercury nitrate and acetate, pyrethrum, pentachlorophenol, derris extract, ethyl bromoacetate, zinc phenyl dithiocarbamate, diphenyl arsenious acid, dichlorodiphenyl-trichloroethane, and p-dichlorobenzene. Tri-alkyl or tri-aryl tin compounds as described in Specification 851,902 may also be incorporated. The wetting agent may be anionic, neutral or cationic, agents containing amine groups being preferred. Of the anionic agents "Armeen 12" and "Duomeen C" (Registered Trade Marks) are suitable and toxic amines and quaternary ammonium compounds may also be used. When cationic agents such as piperidine derivatives are employed the structure may be made a cathode in an electric circuit having anodes positioned in the sea water. The deterrent liquid alone or entrained in a carrier gas is discharged beneath the structure from perforated pipes so that the liquid or gas bubbles rise over the submerged surface to coat it with the deterrent.