Ethylene polymerization process and polyolefin
AssigneeE. I. Du Pont de Nemours and Company
InventorJoel David Citron
Life of this patent
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Abstract
A polymerization to form a branched polyolefin, in which polymerization an ethylene copolymerization catalyst and an ethylene oligomerization catalyst form a series of ethylene oligomers that are α-olefins are both present, gives an improved polyethylene if the oligomerization catalyst has a relatively high Schulz-Flory constant.
Claims31
A polyethylene having a structural index, ST, of about 1.4 or more and/or a processability index, PR, of about 40 or more, and wherein said polyethylene has a density of 0.935 or more, and said polyethylene contains ethyl, n-butyl, and hexyl and longer branches.
A polyethylene having a structural index, ST, of about 1.4 or more and/or a processability index, PR, of about 40 or more, wherein at least one or both of the following are true:
- (a) the ratio of Hex+/Bu is about 4.0 or more;
- (b) the ratio of Hex+/Et is about 4.0 or more;
- and wherein said polyethylene has a number average molecular weight of about 15,000 or more, and said polyethylene contains ethyl, n-butyl, and hexyl and longer branches.
A process for the manufacture of a branched polyethylene, comprising, contacting ethylene with a copolymerization catalyst, and an ethylene oligomerization catalyst which produces a series of α-olefins, wherein the improvement comprises, said oligomerization catalyst which produces said series of α-olefins has a Schulz-Flory constant of about 0.80 to 0.995 under process conditions, and wherein a branched polyethylene produced by said process has a density of 0.930 or more.
Dependencies are inferred from the claim text.