GB950219A - Polymerisation catalyst and process of polymerisation using said catalyst - Google Patents

Abstract

Mixtures of titania and alumina are made by adding water to a mixture of an alkyl titanate and an aluminium alkoxide whereby coprecipitation of the oxides takes place. The hydrated oxides may subsequently be calcined at elevated temperature and then halogenated with a halogenated organic compound at a temperature in the range of 200-1100 DEG F. Suitable halogenating compounds are methylene dichloride, chloroform, carbon tetrachloride, methylene difluoride, fluoroform, and carbon tetrafluoride. In examples, mixtures of titania/ alumina hydrates are precipitated from a benzene solution of n-butyl titanate and aluminium propoxide by the addition of water, calcined at 500 DEG C., and chlorinated by treatment with carbon tetrachloride. The preparation of titania alone is also described in an example by adding water to a benzene solution of tetra-n-butyl titanate and calcining the precipitate at 400 DEG C. for one hour.ALSO:A polymerization catalyst comprises a mixture of (a) a Ziegler-type co-catalyst and (b) a product obtained by contacting at elevated temperature a halogenated organic compound with (I) an oxide of a metal of Group IV(a), V(a), or VI(a) of the Mendel<\>aeeff Periodic Table, or alumina, or (II) a mixture of two or more compounds of (I), or (III) a compound obtained or obtainable by the reaction of two or more compounds of (I). The catalyst is used to polymerize mono-, di-, and polyolefins, and acetylenes. Preferred compounds are ethylene, propylene, butene-1, 4-methylpentene-1, butadiene, styrene, and isoprene. Polymerization may be effected batchwise or continuously for example by employing fixed bed, moving bed, or suspended catalyst techniques. The polymerization is generally carried out in an inert solvent or diluent. The Ziegler-type co-catalyst is usually selected from metals, alloys, hydrides, and organo-metallic compounds of Groups I, II, and III, of the Periodic Table. The preferred co-catalyst is an organo-metallic aluminium compound. The oxides of the metals apart from alumina, may be selected from Ti, Zr, Hf, Th, V, Nb, Ta, Cr, Mo, W, and U. The preferred oxide is titania. The halogenated organic compound may be methylene dichloride, chloroform, carbon tetrachloride, methylene difluoride, fluoroform, or carbon tetrafluoride.