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US 8,778,826 B2Granted
Enhanced procatalyst composition and process
AssigneeW. R. Grace & Co.-Conn.
InventorsKelly Gonzalez, Clark C. Williams, Linfeng Chen
Life of this patent
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Abstract
Disclosed herein are processes for preparing procatalyst compositions and polymers, i.e., propylene-based polymers, produced therefrom. The present procatalyst compositions improve catalyst selectivity and also increase the bulk density of the formant polymer.
Claims10
A process comprising:
- halogenating a procatalyst precursor in the presence of a substituted phenylene aromatic diester at a temperature from about 90° C. to less than or equal to 100° C., wherein the substituted phenylene aromatic diester is 5-tert-butyl-3-methyl-1,2-phenylene dibenzoate, to form a procatalyst composition with ethyl benzoate from 0 wt% to less than 2.3 wt %.
A process comprising:
- first halogenating a procatalyst precursor in the presence of a substituted phenylene aromatic diester at a temperature less than 115° C. to form a procatalyst intermediate, wherein the substituted phenylene aromatic diester is selected from the group consisting of 5-tert-butyl-3-methyl-1,2-phenylene dibenzoate and 4-tert-butyl-1,2phenylene dibenzoate;
- second halogenating the procatalyst intermediate at a temperature greater than or equal to 115° C.;
- to form a procatalyst composition with a bulk density index from about 0.28 to about 0.5.
Dependencies are inferred from the claim text.