| 摘要 |
<p>Low density thermoplastic ethylene co- and terpolymers esp. for blow mouldings are synthesised at low pressure by polymerising ethylene with small amounts of propylene and/or butene-1, in the liquid phase in the presence of a catalyst consisting of a halogenated ester of orthotitanic acid, and a chlorinated org. Al cpd., in a solvent consisting of (I) butane and/or propane, and (II) butane-2, in addition to is not >30 mole % propylene and/or butene-1. Gives polymers with a density of 0.90-0.955 g/cc, and a narrow mol. wt. distribution, good impact resistance at temps. as low as -50 degrees C, and good flex cracking resistance. Mixts. of C4 or C3/C4 hydrocarbons can be used instead of pure butene-1.</p> |
