Controlled-release organotin

Messiha, N.N. and N.E. Ikladious. 1986. Antifouling performance of some new organotin polymers in the Mediterranean and Red Sea. Jour. Controlled Release 3 235-242. 

Organotin-based antifouling have been technically the most successful product for years. They owe this success to a unique mechanism to prevent fouling. They combine the toxic properties of TBT (tributyltin) with a controlled-release mechanism, which guarantee constant activity up to 5 years (coating thickness is the limitation). 

N. F. Cardarelli "Method and Composition for the Long Term Controlled Release of a Non-Persistent Organotin Pesticide from an Inert Monolithic Thermoplastic Material", U. S. Patent 4,166,111, August 28, 1979. 

Trisubstituted organotins are useful biocides in agriculture and industry. They function as fungicides, bactericides, antihelminthics, and rodent repellents (WHO 1980). Tributyltins are used as antifoulants in marine paints but are restricted by the Organotin Antifouling Paints Control Act (June 16, 1988) which limits the type of vessel on which these paints can be used and sets acceptable release limits (U.S. Bureau of Mines 1989). Bis(tributyltin)oxide is used as a preservative for wood products, leather, ropes, fabrics, and paper. 

The two components are kept in temperature-controlled tanks, with pumped re-circulation when injection is not taking place. For the polyurethane system, one tank contains an isocyanate (usually MDI) and the other a mixture of polyol, chain extenders, catalyst and mould release (and possibly blowing agent or reinforcing additives). An amine catalyst accelerates the initiation of the polymerisation, while an organotin catalyst... 

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