People have known from ancient times that copper and certain copper compounds have antifouling effects. So far, cuprous oxide and cuprous thiocyanate are still commonly used antifouling agents with low toxicity and good antifouling effect, and their annual consumption is large. Due to the prohibition of organotin antifouling agents, copper compounds have become the most important antifouling agent. However, the extensive use of cuprous oxide antifouling agents has caused a large amount of deposits of copper compounds in the harbor. Some harbors have deposits as high as tens of tons per year, which has caused serious effects on the water quality of the harbor and the marine biological environment, such as seaweeds. A large number of deaths and poor growth of embryos of marine organisms such as fish, shrimps and crabs have disrupted the ecological balance of the harbor.
The organotin compound antifouling agent popular in the middle and late last century is an antifouling agent with higher efficiency than cuprous oxide. Tributyltin oxide, tributyltin and fluoride, triphenyltin chloride, and triphenyltin fluoride have been widely used. The organic tin antifouling agent is low in dosage, high in efficiency, and has a broad spectrum. The antifouling period of the antifouling paint made can reach 5 years. It is not only suitable for steel surfaces, but also for aluminum alloy ships without generating electricity. Chemical corrosion phenomenon.
However, organotin compounds are teratogenic and accumulate in marine organisms, such as fish and shellfish. They not only cause genetic variation of marine organisms, but also enter the food chain, seriously affecting the inheritance and survival of humans and other organisms. In the latter part of the last century, various countries have banned organotin antifouling coatings by legislation. The International Maritime Organization (IMO) has clearly stated that the ban on organotin compounds will take effect in 2003, and by 2008, organotin compounds will be completely banned as antifouling agents.
However, it has not yet been possible to find a substitute for antifouling agents whose effectiveness and broad-spectrum are comparable to organotin compounds. The focus now is on antifouling agents containing tin-free organic compounds. Sea-Nine 211 (chemical name 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one), Copper Omadine (copper pyrithione, also known as Austrian Malbutinone), Irgarol 1051 (N-cyclopropyl-N'-(1,1-dimethylethyl)-6-(methylthio)-1,3,5-triazine-2,4 -Diamine] etc. Among them, Sea-Nine 211 has a good inhibitory effect on animals such as diatoms, bacteria, algae, and barnacles. It has high efficiency and can be quickly decomposed through hydrolysis, photodegradation and biodegradation without accumulative effects. The marine environment is very safe. Copper Omadine has proven to be non-polluting to fish cultured in cages. Antifouling Coatings Irgarol 1051 is effective against algae and bacteria, but not against animal fouling organisms. These organic antifouling agents need to be used in conjunction with other antifouling agents such as cuprous oxide to have a better overall effect.