出典:Wiktionary
coal tar (countable かつ uncountable, 複数形 coal tars)
出典:『Wiktionary』 (2010/06/23 11:30 UTC 版)
出典:『Wiktionary』 (2014/12/19 01:35 UTC 版)
出典:Wikipedia
出典:『Wikipedia』 (2011/05/27 11:31 UTC 版)
Coal tar is a brown or black liquid of high viscosity, which smells of naphthalene and aromatic hydrocarbons. Coal tar is among the by-products when coal is carbonized to make coke or gasified to make coal gas. Coal tars are complex and variable mixtures of phenols, polycyclic aromatic hydrocarbons (PAHs), and heterocyclic compounds, about 200 substances in all.