Process and catalyst for producing mildly elastomeric primarily isotactic polymers
AssigneeShell Oil Company
InventorRobert C. Job
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Abstract
A process and a catalyst for the production of mildly elastomeric primarily isotactic polyolefins characterized by intermediate average block lengths wherein olefins are polymerized in the presence of the catalyst which comprises the reaction product of a magnesium alkoxide and a tetravalent titanium halide which takes place in the presence of an electron donor, an organoaluminum compound, and a selectivity control agent which is an effectively unhindered heterocyclic aromatic nitrogen compound.
Claims6
A catalyst for use in the polymerization to mildly elastomeric primarily isotactic polypropylene or poly-1-butene characterized by intermediate average block lengths which comprises:
- (a) The reaction product of a magnesium alkoxide or a magnesium aryl oxide an a tetravalent titanium halide wherein the reaction takes place in the presence of an electron donor,
- (b) An organoaluminum compound, and
- (c) A selectivity control agent which is selected from the group consisting of pyrazine, 3,4,5-trichloropyridazine, 1,3,5-triazine, phenazine, pyridine, 2,6-dimethylpyriazine, quinazoline, 4,6-dichloropyrimidine, 2-picoline, 2,3,5-trimethylpyrazine, acridine, 2-methylpyrazine, 2,5-dimethylpyrazine, 2,3-dimethylpyrazine, 2,3-dichloroquinoxaline, quinoline, pyridazine, 1,10-phenantholine, 2,4-dichloropyrimidine, 2,6-diphenylpyridine.
Dependencies are inferred from the claim text.