| 摘要 |
Substances containing a lower halide of titanium and aluminium halide are formed by reduction of titanium tetrahalide with A1 in the presence of hydrogen halide. The halide may be chloride, bromide or iodide. The tetrahalide is present in amount at least stiochiometric with respect to the A1. The reaction, which is exothermic, is carried out under reflux; liquid diluent, e.g. aliphatic hydrocarbons or chlorinated hydrocarbons, or excess titanium tetrahalide, in which cases the mixture may be heated to boiling point until the reaction starts, or aromatic hydrocarbons, may be added. The reaction is performed in the absence of moisture or oxygen; an inert atmosphere, e.g. N2 or Ar, may be present. Hydrogen halide, which may be in excess, is passed continuously or intermittently into the reaction mixture. The A1 is preferably finely divided, e.g. of particle size 0.5 m . The product is a slurry from which a brown or purple-brown solid may be recovered. The product may then be milled dry or in liquid, and used with an organo-metallic compound, e.g. a Group I-III metal alkyl or alkyl halide, to form a Ziegler-Nalta catalyst for polymerization of unsaturated hydrocarbons; the metal may be A1. The product may also be used as a feed or addition to a feed in a vapour phase oxidation reactor to form nucleating agents for TiO2, which is prodiced predominantly as rutile. |
