| 摘要 |
Propylene is polymerized principally to dimer by contacting in the vapour phase with an acidic clay or silica-alumina having ion-exchange characteristics in the presence of water and/or an alcohol. When water is used the weight ratio of propylene to water may be 2,5-30:1. Suitable conditions are 550 DEG -1000 DEG F., superatmospheric pressure, e.g. 25-250 p.s.i.g., space velocities of 550-3300 volumes of propylene at standard temperature and pressure per volume of catalyst per hour. Instead of water may be used methanol, ethanol or isopropanol. The catalyst may have been partially neutralized by treatment with a basic, e.g. sodium carbonate, solution as described in Specification 935,288. |
