| 摘要 |
Isocyanates are prepared by reacting a primary amine, or an acid addition salt thereof, with at least a stoichiometric quantity of phosgene in the presence of a quantity of a tertiary amine sufficient to combine with the HCl formed during the reaction, and with any other acid which may be liberated. A large number of mono- and poly-amines are specified as starting materials. N,N-Dimethyl- and N,N-diethyl aniline are preferred tertiary amines. The reaction is usually effected at -10 DEG to 30 DEG C., but temperatures as high as 150 DEG C. may be employed. Examples relate to the preparation of bis-(4-isocyanatophenyl)-dimethyl methane, p-phenylene diisocyanate, cyclohexylisocyanate, ethyl isocyanate, hexamethylene diisocyanate, 1,4-butylene-bis-isocyanato-isopropyl ether, p-chlorophenylisocyanate, naphthalene - 2,7 - di - isocyanate, isopropylidene - 2,4,41 - triisocyanato - dibenzene and diphenylsulphide-4,41-diisocyanate. |
