Patent ID: 11891460
Assignee: W.R. GRACE & CO.—CONN.
Field: Macromolecular chemistry, polymers (Chemistry)
Classification: CPC C | IPC C

Claim 18:
19. A process for producing olefin polymers comprising:
polymerizing an olefin in the presence of an activated solid catalyst component in a gas phase polymerization reactor, the activated solid catalyst component comprising:
(a) a halide-containing magnesium compound;
(b) a titanium compound wherein titanium has as oxidation state of at least +3 and +2;
(c) an organosilicon compound containing Si—O groups;
(d) an alkyl-aluminum compound;
(e) a supportive electron donor comprising a mono benzoate, the supportive electron donor being present in the catalyst component in an amount from about 0.01% to about 5% by weight;
(f) at least one internal electron donor, the internal electron donor comprising an aryl diester, the at least one internal electron donor being present in the catalyst component in an amount from about 1% to about 15% by weight; and
(g) a polymer formed from an alpha-olefin having the formula: CH2═CHR1, wherein R1 comprises hydrogen, or a C1 to C7 alkyl group, the alpha-olefin polymer forming a coating on the catalyst particles and being present in the catalyst component in an amount from about 0.3 g to about 200 g of polymer per gram of catalyst particles;
wherein the activated solid catalyst component is prepared outside of the polymerization reactor and fed to the reactor.