摘要 |
<p>A transition metal composition has the formula: TiCl3(AlRxX3-x)nEaL? where E is an ether or thioether; L is an organic phosphorus- containing Lewis Base; and a and b are each greater than 0.001 and not more than 0.50. The composition has a low surface area, typically less than 50 m2/g. The composition can be prepared by reacting titanium tetrachloride with an organoaluminum compound, optionally heating the reaction product, contacting the reaction product at an elevated temperature with at least one of E and L and washing the product subsequent to the contacting with E. In the composition, E is conveniently di-n-butyl ether or di-isoamyl ether and L can be an organic phosphine, phosphine oxide, phosphite or phosphate. The composition can be used in a polymerisation catalyst to polymerise or copolymerise olefins monomers. Copolymers having an advantageous combination of low temperature brittle point and Flexural Modulus are disclosed.</p> |