Paint cuprous oxide

The amount of biocides needed in an antifouling paint will be determined by actual tests performed in real life. A rule of thumb says that the minimum level of protection with copper is a leaching rate of 10 pg/(cm2 day) (WHOI, 1952). The amount of cuprous oxide can be up to 40 wt % of an antifouling paint and it is normally assisted by booster biocides (5 to 10 wt %) to provide full protection against both animals and algae. The amount of biocides will be based on practical performance and, at the same time, be restricted to given legislation. 

Ferry, J.D., Carritt, D.E. Action of Antifouling Paints. Solubility and Rate of Solution of Cuprous oxide in Seawater. Industrial and Engineering Chemistry, 38 (6) (1946), 612-617... 

Cuprous oxide has been used in the prepn of cuprous salts, in ceramics, fungicides, pyrotechnics, electroplating and in antifouling paints. These paints were used extensively by the US Navy during WWII (Refs 3, 6, 7 9 and Addnl Refs E F)... 

Visco-Stab. [Atochem N. Am.] Paint stabilizer, vise, stabilizer for cuprous oxide-containing paints based on bioMeT antifoulant polymen. 

Cuprous Oxide. Red copper oxide C.I. 77402 Perenex Yellow Cuprocide Copper-Sandoz Caocobre. CujO mol wt 143.08. Cu 88.82%, O 11.18%. Occurs in nature as the mineral cuprite (red to reddisli-brown octahedral or cubic crystals). Prepd commercially by furnace reduction of mixtures ot copper oxides with Cu Drapeau, Johnson, U.S. pats. 2,758,014 2,891,842 (1956, 1959 to Glidden) by decompn of copper ammonium carbonate Rowe, U.S. pat. 2,474,497 Klein, U.S. pat. 2.474,533 (both 1949 to Lake Chemical) Rowe, U.S. pat. 2,536,096, Munn, U.S. pat. 2,670,273 (1951, 1954 to Mountain Copper) by treatment of Cu(OH)j with S02 Rowe, U pat. 2,665,192 (1954 to Mountain Chemical) or by electrolysis of an aq soln of NaCI between Cu electrodes Arend, Paint Technology 13, 265 (1948). Laboratory prepns Glemser, Seuer in Handbook of Preparative Inorganic Chemistry, vol. 2, G. 

In the soluble matrix type cuprous oxide and sometimes other biocides, is incorporated into a resin binder. The acidic resin slowly reacts with the sea water (pH approximately 8.0) and dissolves continuously exposing the cuprous oxide particles that are gradually released at the water/solid interface. The newly created surface provides antifouling properties. Depending on thickness the life of these paints on ships hulls, in contact with sea water, is 1 - 2 years. 

Black twisted nylon and polypropylene ropes used to rig and retrieve test platforms were unaffected. Grappling lines attached to platforms, made of steel wire jacketed with extruded high-density PE, prevented corrosion of the steel. PE is also used to protect submerged telephone cables. Plastic primers such as epoxy are used to prevent antifouling paints from corroding metals. These paints generally use cuprous oxide to prevent the growth of barnacles, but at the same time can be harmful to metal. 

Cuprous oxide is a red pigment used almost exclusively in autifouling ship bottom paints to kill barnacles. 

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