| 摘要 |
<p>Oligomeric carbonate bischloroformates are prepared with low phosgene usage by phosgenating a dihydroxyaromatic compound in an interfacial reaction in the presence of small amounts of a trialkylamine, preferably, triethylamine. In this invention, the molar ratio of phosgene to dihydroxyaromatic compound, hydrolysis of phosgene, formation of such byproducts as monochloroformates and hydroxyl-terminated polycarbonate oligomers, and batch time are minimized and consumption of the dihydroxyaromatic compound is substantially complete.</p> |
