Patent GB-862604-A (GB)
Title: Improvements in or relating to olefin polymerisation and catalysts for use therein
IPC: B01J23/16
Filed: 1959-09-21
Abstract: Polymerization (including copolymerization) of C2-C5 olefines, specifically ethylene or propylene, is effected by means of a supported catalyst wherein the silica/alumina carrier material has been treated with an alkali compound, e.g. of Li, Na or K, and the material heated simultaneously or subsequently at 200-800 DEG  C. Specified catalytically-active components are oxides of Cr, Mo or V, which may be supported in their highest valency state and thereafter reduced by known methods.  An additional quantity of catalyst-free inert carrier material may be added in polymerization.  The polymerization is preferably carried out in the liquid phase, with the usual hydrocarbon or chlorinated hydrocarbon diluent; it may be a batch or continuous process.  The polymers produced may be used in the manufacture or coating of articles.  Specifications 804,642 and 843,750 are referred to.ALSO:A catalyst carrier material comprising the oxides of Si and Al at least partially chemically bound together is reacted with a compound which yields an alkaline aqueous solution and is an oxide, hydroxide, alcoholate or a salt of an acid, the acid part being volatile at 200-800 DEG C. leaving a non-volatile alkaline residue; simultaneously or subsequently, the carrier material is heated at 200-800 DEG C.  The quantity of alkaline compound required, in equivalents per gram of carrier material, is 20-250% of the quantity of alkali required to increase to 7 (at 20 DEG C.) the pH of 75 ml. of very pure water, shaken with 1 gram of carrier material. The preferred alkaline compounds are those of Li, but K and Na are also mentioned; preferably hydroxides or carbonates are used, but oxalates or acetates are mentioned as examples of organic acid salts. Components active as polymerization catalysts, specifically oxides of Cr, Mo and V, may be supported on a weakly acid or non-acid silica/alumina carrier prepared as described above; these metals may be supported in their highest valency state, from which they may be afterwards reduced.  In examples, the carrier material is an activated cracking catalyst of Al2O3:SiO2 weight ratio 25:75 and specified particle size, pore volume and surface area; the alkali compound is LiOH or KOH, in the case of a catalyst prepared from CrO3 and subsequently reduced by treatment with iso-octane at 80 DEG C., or LiOH in the case of a catalyst prepared from ammonium vanadate (evidently decomposed to V2O5) and subsequently reduced with AlEt3. Methods of reducing the catalytically active components mentioned generally are:- (1) using hydrocarbons at below 180 DEG C. (see Specification 843,750) for reducing CrO3; (2) using H2, CO or hydrocarbons at 300-650 DEG C. for reducing CrVI or VV compounds; (3) use at lower temperatures, e.g. 20-200 DEG C., of reducing agents such as alkali metals, alkaline earth metals, boron or metal hydrides and alkyls and alkaline earth carbides.  An additional quantity of catalyst-free inert carrier material may be utilized in polymerization.  Specification 804,642 also is referred to.