Passivated Supports for Use with Olefin Polymerization Catalysts
AssigneeNOVA Chemicals (International) S.A.
InventorsDarryl J. Morrison, Charles Ashton Garret Carter, Amy Marie Baltimore
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Abstract
A phosphinimine catalyst immobilized on a passivated inorganic oxide support, had high activity at low co-catalyst concentrations and gave, under gas phase polymerization conditions, ethylene copolymer with a high molecular weight. A method of making a passivated silica support involves treatment of silica with an organoaluminum compound, a diorganomagnesium compound and a source of chloride (to make MgCl2) under anhydrous conditions and in the absence of polar solvents.
Claims25
An olefin polymerization catalyst comprising:
- a passivated support, a group 4 single site catalyst and a cocatalyst, the passivated support comprising silica which has been treated with i) an organoaluminum compound and ii) magnesium chloride, wherein the magnesium chloride is generated by addition of a diorganomagnesium compound and a source of chloride to the organoaluminum treated silica, provided that the source of chloride is not a transition metal chloride.
A method of making an olefin polymerization catalyst said method comprising:
- a) making a passivated support by carrying out the following steps:
- i) dehydrating silica;
- ii) adding an organoaluminum compound to the dehydrated silica;
- iii) adding a diorganomagnesium compound to the product of step ii);
- and iv) adding a source of chloride to the product of step iii), provided that the source of chloride is not a transition metal chloride;
- and
- b) adding to the passivated support, a group 4 single site catalyst and a cocatalyst in any order.
An olefin polymerization process comprising contacting ethylene and at least one alpha-olefin with an olefin polymerization catalyst, said olefin polymerization catalyst comprising:
- a passivated support, a group 4 single site catalyst and a cocatalyst;
- wherein the passivated support comprises silica which has been treated with i) an organoaluminum compound and ii) magnesium chloride, wherein the magnesium chloride is generated by addition of a diorganomagnesium compound and a source of chloride to the organoaluminum treated silica, provided that the source of chloride is not a transition metal chloride.
A polyethylene comprising at least 75 wt % of ethylene units with the balance being alpha-olefin units, said polyethylene having a CDBI of greater than 55%, and said polyethylene being made with an olefin polymerization catalyst comprising:
- a passivated support, a phosphinimine catalyst and a cocatalyst wherein the passivated support comprises silica which has been treated with i) an organoaluminum compound and ii) magnesium chloride, wherein the magnesium chloride is generated by addition of a diorganomagnesium compound and a source of chloride to the organoaluminum treated silica, provided that the source of chloride is not a transition metal chloride;
- and wherein the phosphinimine catalyst has the formula:
- (1,2-(R2)(Ar—F)Cp)Ti(N═P(t-Bu)3)X2, where R2 is a hydrocarbon group, Ar—F is a perfluorinated aryl group, a 2,6 fluoro substituted phenyl group, a 2,4,6 fluoro substituted phenyl, or a 2,3,5,6 fluoro substituted phenyl group, and X is an activatable ligand;
- and wherein the cocatalyst is an alkylaluminoxane.
Dependencies are inferred from the claim text.