| 摘要 |
1302256 Polyisocyanates MARATHON OIL CO 20 May 1970 [4 June 1969] 24461/70 Heading C3R Polyisocyanates containing isocyanurate rings are prepared by reacting poly-(chloroalkylated) mono-substituted benzene compounds with alkali metal or alkaline earth metal cyanates and alkal i metal or alkaline earth metal bromides or iodides in dipolar aprotic solvents. In examples toluene is chloromethylated and then reacted with sodium cyanate and sodium bromide in dimethylformamide. |
