Catalyst composition for polymerizing ethylene
AssigneeUnion Carbide Corporation
InventorsBurkhard E. Wagner, George L. Goeke, Frederick J. Karol, Kathleen F. George
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Abstract
Catalyst compositions suitable for producing high density ethylene polymers in a low pressure gas phase process with low accompanying ethylene hydrogenation are produced by forming a precursor composition from a magnesium compound, titanium compound and electron donor compound; diluting said precursor composition with an inert carrier material; treating said diluted precursor composition with a boron halide compound; and activating the precursor composition with an organo aluminum compound.
Claims22
A precursor composition suitable as a component of a catalyst composition capable of producing high density ethylene homopolymers and copolymers under a pressure of less than 1000 psi with low accompanying ethylene hydrogenation, said precursor composition having the formula
- Mg.sub.m Ti(OR).sub.n X.sub.p [ED].sub.q
- wherein
- R is an aliphatic or aromatic hydrocarbon radical containing from 1 to 14 carbon atoms, or COR' wherein R' is an aliphatic or aromatic hydrocarbon radical containing from 1 to 14 carbon atoms,
- X is selected from the group consisting of Cl, Br, I, and mixtures thereof,
- ED is an organic electron donor compound selected from the group consisting of alkyl esters of aliphatic and aromatic acids, aliphatic ethers, cyclic ethers and aliphatic ketones,
- m is 0.5 to 56,
- n is 0, 1 or 2,
- p is 2 to 116, and
- q is 2 to 85,
- said precursor composition being diluted with an inert carrier material and containing from 0.1 mol to 3.0 mols of boron halide compound per mol of electron donor in said precursor composition,
- said boron halide compound having the formula
- BR.sub.c X'.sub.3-c
- wherein
- R is an aliphatic or aromatic hydrocarbon radical containing from 1 to 14 carbon atoms or OR', wherein R' is an aliphatic or aromatic hydrocarbon radical containing from 1 to 14 carbon atoms,
- X' is selected from the group consisting of Cl, Br, and mixtures thereof, and
- c is 0 or 1 when R is an aliphatic or aromatic hydrocarbon and 0, 1 or 2 when R is OR'.
A process for preparing a treated precursor composition suitable as a component of a catalyst composition capable of producing high density ethylene homopolymers and copolymers under a pressure of less than 1000 psi with low accompanying ethylene hydrogenation which comprises
- (A) forming a precursor composition of the formula
- Mg.sub.m Ti(OR).sub.n X.sub.p [ED].sub.q
- wherein
- R is an aliphatic or aromatic hydrocarbon radical containing from 1 to 14 carbon atoms, or COR' wherein R' is an aliphatic or aromatic hydrocarbon radical containing from 1 to 14 carbon atoms,
- X is selected from the group consisting of Cl, Br, I, and mixtures thereof,
- ED is an organic electron donor compound selected from the group consisting of alkyl esters of aliphatic and aromatic acids, aliphatic ethers, cyclic ethers and aliphatic ketones,
- m is 0.5 to 56,
- n is 0, 1 or 2,
- p is 2 to 116, and
- q is 2 to 85,
- by dissolving at least one magnesium compound and at least one titanium compound in at least one liquid organic electron donor compound so as to from a solution of said precursor composition in said electron donor compound,
- said magnesium compound having the structure MgX.sub.2,
- said titanium compound having the structure Ti(OR).sub.a X.sub.b wherein a is 0, 1 or 2, b is 1 to 4 inclusive and a+b=3 or 4,
- said magnesium compound, said titanium compound, and said electron donor compound being employed in such amounts as to satisfy the values of m, n, p and q,
- (B) diluting said precursor composition with an inert carrier material, and
- (C) treating said diluted precursor composition with a boron halide compound having the formula
- BR.sub.c X'.sub.3-c
- wherein
- R is an aliphatic or aromatic hydrocarbon radical containing from 1 to 14 carbon atoms or OR', wherein R' is an aliphatic or aromatic hydrocarbon radical containing from 1 to 14 carbon atoms,
- X' is selected from the group consisting of Cl, Br, and mixtures thereof, and
- c is 0 or 1 when R is an aliphatic or aromatic hydrocarbon radical and 0, 1 or 2 when R is OR'.
Dependencies are inferred from the claim text.