Catalyst composition for copolymerizing ethylene

Claim 1

A continuous process for producing ethylene copolymers containing at least 90 mol percent of ethylene and no more than 10 mol percent of one or more alpha olefins containing from 3 to 8 carbon atoms, said copolymers being produced in granular form and having a density of from 0.91 g/cm 3 to 0.96 g/cm 3 , which comprises contacting a mixture of ethylene and at least one alpha olefin containing from 3 to 8 carbon atoms, at a temperature of from 30° C. to 115° C. and a pressure no greater than 1000 psi, in a gas phase reaction zone, with particles of a catalyst system comprising a 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 carboxylic 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 treated with from 0.1 mol to 3.0 mols of a hydrocarbyl aluminum dihalide compound per mol of electron donor in said precursor composition, said hydrocarbyl aluminum dihalide compound having the formula RAlX.sub.2 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, and X is selected from the group consisting of Cl, Br, I, and mixtures thereof, and said precursor composition being completely activated with from 10 mols to 400 mols of activator compound per mol of such precursor composition, said activator compound having the formula Al(R").sub.d X'.sub.e H.sub.f wherein X' is Cl or OR"', R" and R"' are saturated hydrocarbon radicals containing from 1 to 14 carbon atoms, e is 0 to 1.5, f is 0 or 1, and d+e+f=3.