Preparation of a catalyst for and a method of producing linear low density polyethylene

Claim 1

A process for preparing a catalyst for use in the production of linear low density polyethylene, comprising the steps of:- a) transferring magnesium from a liquid medium onto a solid porous carrier in contact with the liquid medium, the carrier containing reactive, surface hydroxyl groups, the liquid medium containing at least one organomagnesium composition having the empirical formula R n MgR' (2-n) , where R is a stable organic moiety and R' is a stable organic moiety or a halogen atom, and n is a rational number between 0.5 and 2, the magnesium being transferred in chemically combined form onto the carrier by reaction between the organomagnesium composition and the surface hydroxyl groups and by precipitation onto the carrier to produce a supported magnesium composition, and b) reacting the supported magnesium composition produced in step (a) with at least one tetravalent titanium compound in a liquid medium such that the molar ratio of the titanium compound in the liquid medium to the reacted magnesium in the supported magnesium composition is greater than unity, the tetravalent titanium compound being soluble in said liquid medium, and said supported magnesium composition being essentially insoluble in said liquid medium, the reaction producing on said carier a reacted form of titanium which is insoluble in said liquid medium.

Claim 10

A method of producing a linear low density polyethylene polymer selected from ethylene/1-butene copolymers, ethylene/1-hexene copolymers, ethylene/1-butene/l-hexene terpolymers, ethylene/propylene/1-hexene terpolymers and ethylene/propylene/l-butene terpolymers, said process comprising conducting the polymerization in the presence of catalyst repared by a process as claimed in any preceding claim.

Claim 11

A method of producing a linear low density polyethylene polymer having a density of 0.93 g/cc or less, said polymer being a polymer of ethylene with 1-hexene and said process comprising conducting the polymerization in the gas phase in the presence of catalyst prepared by a process comprising the steps of: (i) transferring magnesium from a liquid medium to a solid, porous carrier, said carrier being in contact with said liquid medium, said liquid medium containing at least one organomagnesium composition having the empirical formula R n MgR' (2-n) , where R and R' are the same or different and represent stable organic moieties, provided that R' may also be halogen and n is a rational number from about 0.5 to 2; and (ii) reacting said supported magnesium composition of step (i) with at least one tetravalent titanium compound in a liquid medium, said tetravalent titanium being soluble in said liquid medium, and said supported magnesium composition, including the supported material thereof, being essentially insoluble in said liquid medium, whereby a reacted form of titanium which is insoluble in said liquid medium becomes supported on said carrier.

Claim 12

A method of producing a linear low density polyethylene polymer having a density of 0.93 g/cc or less, said polymer being a polymer of ethylene with 1-hexene and said process comprising conducting the polymerization in the gas phase in the presence of catalyst prepared by a process comprising the steps of: (i) transferring magnesium from a liquid medium to a solid, porous carrier, said carrier being in contact with said liquid medium, said liquid medium containing at least one organomagnesium composition having the empirical formula R n MgR' (2-n) , where R and R' are the same or different and represent stable organic moieties, provided that R' may also be halogen and n is a rational number from about 0.5 to 2; and (ii) reacting said supported magnesium composition of step (i) with at least one tetravalent titanium compound in a liquid medium, said tetravalent titanium being soluble in said liquid medium, and said supported magnesium composition, including the supported material thereof, being essentially insoluble in said liquid medium, whereby a reacted form of titanium which is insoluble in said liquid medium becomes supported on said carrier.