Abstract: A transition metal composition has the formula:TiCl.sub.3 (AlR.sub.x X.sub.3-x).sub.n E.sub.a L.sub.bwhere E is an ether or thioether; L is a defined ester, an amine or a ketone; 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 m.sup.2 /g. The composition can be prepared by reacting titanium tetrachloride with an organo-aluminium 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 treatment with E. In the composition, E is conveniently di-n-butyl ether or di-isoamyl ether and L can be tetramethylethylenediamine; ethyl benzoate; benzophenone; glycerol monostearate; glycerol triacetate; glycerol tripalmitate; glycerol trimethacrylate; pentaerythritol tetra-acrylate or ethyl phenyl acetate. The composition can be used as a component of a catalyst for the polymerization of olefine monomers such as propylene.

Abstract: A transition metal composition has the formula:TiCl.sub.3 (AlR.sub.x X.sub.3-x).sub.n E.sub.a L.sub.bwhere 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 m.sup.2 /g. The composition can be prepared by reacting titanium tetrachloride with an organoaluminium 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 polymerization catalyst to polymerize or copolymerize olefine monomers. Copolymers having an advantageous combination of low temperature brittle point and Flexural Modulus are disclosed.

Abstract: A transition metal composition has the formula:TiCl.sub.3 (AlR.sub.x X.sub.3-x).sub.n E.sub.a L.sub.bwhere E is an ether or thioether; L is an organic sulphur-containing compound; 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 m.sup.2 /g. The composition can be prepared by reacting titanium tetrachloride with an organo-aluminium compound, optionally heating the reaction product, contacting the reaction product at an elevated temperature with at least E, and preferably L and washing the product. In the composition, E is conveniently di-n-butyl ether or di-isoamyl ether and L can be phenoxathiin or diphenyl sulphone. The composition can be used as a component of a catalyst for the polymerization of olefine monomers such as propylene.

Abstract: A reaction product of a transition metal compound, for example titanium tetrachloride, and an organo-compound of a non-transition metal, for example an aluminium dialkyl halide, is treated with a sulphur containing organic compound, in an amount of up to 2.00, preferably up to 1.50 molar relative to the transition metal compound. The mixture is heated to a temperature in the range from 60.degree. C. up to 160.degree. C. Before treating with the sulphur compound, the reaction product can be heated to a temperature of up to 160.degree. C. The Lewis Base compound is a sulphone, a sulphonamide or a fused-ring heterocyclic compound such as phenoxathiin. The product obtained can be used as a component of an olefine polymerization catalyst.

Abstract: A transition metal composition has the formula:TiCl.sub.3 (AlR.sub.x X.sub.3-x).sub.n E.sub.a L.sub.bwhere E is an ether or thioether; L is an organic sulphur-containing compound; 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 m.sup.2 /g. The composition can be prepared by reacting titanium tetrachloride with an organo-aluminium compound, optionally heating the reaction product, contacting the reaction product at an elevated temperature with at least E, and preferably L and washing the product. In the composition, E is conveniently di-n-butyl ether or di-isoamyl ether and L can be phenoxathiin or diphenyl sulphone. The composition can be used as a component of a catalyst for the polymerization of olefine monomers such as propylene.

Abstract: A transition metal composition has the formula:TiCl.sub.3 (AlR.sub.x X.sub.3-x).sub.n E.sub.a L.sub.bwhere E is an ether or thioether; L is a defined ester, an amine or a ketone; 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 m.sup.2 /g. The composition can be prepared by reacting titanium tetrachloride with an organo-aluminium 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 treatment with E. In the composition, E is conveniently di-n-butyl ether or di-isoamyl ether and L can be tetramethylethylenediamine; ethyl benzoate; benzophenone; glycerol monostearate; glycerol triacetate; glycerol tripalmitate; glycerol trimethacrylate; pentaerythritol tetra-acrylate or ethyl phenyl acetate. The composition can be used as a component of a catalyst for the polymerization of olefine monomers such as propylene.

Abstract: Gas-phase polymerization of an .alpha.-olefin, especially propylene, in a stirred or fluidized bed of substantially uniform and approximately spherical carrier particles of an .alpha.-olefin polymer of diameter 100-500 .mu.m, using a catalyst comprising an organo-metallic compound and a solid transition metal compound which has a particle size of less than 5 .mu.m, produces a propylene polymer having unexpectedly good powder flow characteristics. The transition metal compound is conveniently a titanium trichloride-containing material which has been treated with a dialkyl ether solution.