| 摘要 |
<p>In a continuous process for the polymerization of isobutylene at - 112 DEG to 104 DEG F. in the presence of a Friedel-Crafts catalyst and an inert non-polar solvent for the polymer, the polyisobutylene is subsequently separated by flashing the reaction mixture at elevated pressure in at least two stages, the pressure in each stage being successively reduced. The recovered isobutylene and solvent are admixed with fresh feed, purified and recycled. The first flashing may be at 15-75 p.s.i.g. and 150-250 DEG F., and the second flashing at 0-15 p.s.i.g. and 200-300 DEG F.; optionally steam stripping at atmospheric pressure may finally be effected. The solvent used may be an alkane, an alkyl halide or carbon disulphide and in the examples hexane is used with aluminium chloride as catalyst. Catalyst may be destroyed with water, caustic or alcohol. A part of the bottoms from the first stage may be used as viscosity index controller in high-boiling petroleum oils such as lubricating oils. Specification 798,015 is referred to.</p> |
