Activated catalyst components for olefin polymerization
AssigneeW. R. Grace & Co.-Conn.
InventorVladimir Marin
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Abstract
An activated solid catalyst component is disclosed formed from a magnesium compound, a titanium compound, an organosilicon compound, a supportive electron donor, and at least one internal electron donor. The solid catalyst component is activated to include titanium and carbon bonds by reaction with an activation agent, such as an aluminum compound. In one embodiment, small amounts of polymer are polymerized with the catalyst component during activation. The activated catalyst component is stable and, when formed, can later be used to produce various polyolefin polymers. The activated catalyst component has controlled reaction kinetics so that the catalyst does not overheat and degrade during initial polymerization.
Claims20
An activated and non-phthalate solid catalyst component for olefin polymerization comprising a reaction product of:
- (a) a halide-containing magnesium compound;
- (b) a titanium compound containing titanium in an oxidation state of at least +3 and +2;
- (c) an organosilicon compound containing Si—O groups;
- (d) an alkylaluminum compound;
- (e) a supportive electron donor comprising a monobenzoate, 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 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, 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 component.
A process for producing an activated solid catalyst component comprising:
- a. forming a catalyst precursor component by reacting a magnesium alkoxide Mg(OR)nX2-n, or magnesium alcholate MgX2mR′OH with Ti(OR″)gX4-g wherein X is Br, Cl, or I;
- and n is 1 or 2;
- m is 0.5-10;
- g is 0, 1, 2, 3, or 4;
- and R, R′, R″ are independently C1-C10 alkyl, the catalyst precursor further containing a supportive electron donor and an internal electron donor
- b. reacting the product obtained from (a) with a trialkyl aluminum compound in the presence of an organosilicon compound having the following formula R2nSi(OR3)4-n, wherein R2 is H, alkyl, or aryl;
- each R3 is alkyl, or aryl;
- n is 0, 1, 2 or 3,
- c. reacting the product obtained in (b) with an olefin having the formula CH2═CHR′ wherein R′═H, or a C1-C7 alkyl group and polymerizing the olefin to form a polymer coating on the solid catalyst component particles, the olefin polymer being present in an amount of less than 200 g per 1 g of the activated solid catalyst component,
- d. isolating the activated solid catalyst component.
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.
Dependencies are inferred from the claim text.