| 摘要 |
<p>New components of catalysts for the polymerisation of alpha-olefins comprise a Ti cpd. chemically linked to a Mg dihalide vehicle in the form of spheroidal particles of av. dia. 1-100 mu, surface area >90 m2/g, and porosity 0.3 cm3/g. The components are used, together with organometallic cpds. of Gp. II and III metals, esp. trialkyl Al, for the stereospecific polymerisation of alpha-olefins of formula CH2=CHR (where R is H or 1-6C alkyl) esp. propylene. Previous catalysts either highly active and highly stereospecific but do not yield polymers of controlled morphology and good flow properties; or give controlled particle size but are not very stereospecific. The new cpds. overcome these disadvantages, e.g. >50% of the particles are of dia. 100-500 mu.</p> |
