| 摘要 |
<p>Monomer and dispersing agent are returned into a polymerisation system in which >=1 alpha-alkene is polymerised with a gp. IVB, VB or VIB transition metal catalyst in an inert liq. dispersing medium to give a soln. or suspension of the polymer, by (1) recovering the polymer from the soln. or dispersion by vaporising the unconverted monomer and dispersing medium. (2) partially condensing the vaporised mixt., (3) contacting the residual gas/vapour stream with liq. dispersing agent, (4) recycling a preponderant amt. of the gas/vapour stream for re-use and (5) releasing a small amt. of the gas/vapour stream from the system. Pref. in stage (3) the gas/vapour stream is washed with dispersing agent at -40+50 degrees C, esp. -20 to +20 degrees C. Less useful material (monomer and dispersing agent) is lost per unit vol. of inert gas released than is the case with systems in which the recycle vapour stream is not scrubbed. The reduced organic cpd. content of the released gas also reduces atmospheric pollution problems.</p> |
