Process and catalyst for producing reactor blend polyolefins

• US 4,937,299 A
• Filed: 02/01/1985
• Issued: 06/26/1990
• Est. Priority Date: 06/06/1983
• Status: Expired due to Term

• Current Assignee: Exxon Research and Engineering Company (Exxon Mobil Corporation)
• Original Assignee: Exxon Research and Engineering Company (Exxon Mobil Corporation)
• Inventors: Ewen, John A., Welborn, Howard C. Jr.
• Primary Examiner(s): Smith, Edward J.
• Application Number:
  US06/697,308
• Time in Patent Office: 1,971 Days
• Field of Search: 502/113, 526/114, 526/116, 526/119, 526/160
• US Class Current: 526/119
• CPC Class Codes: C08F 10/00 Homopolymers and copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond
• CPC Class Codes: C08F 4/633 with metals covered by group C08F4/62 or compounds thereof
• CPC Class Codes: C08F 4/65904 in combination with another component of C08F4/64
• CPC Class Codes: C08F 4/65912 in combination with an organoaluminium compound
• CPC Class Codes: C08F 4/65922 containing at least two cyclopentadienyl rings, fused or not
• CPC Class Codes: C08L 2205/02 containing two or more polymers of the same C08L -group
• CPC Class Codes: C08L 2205/025 containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure
• CPC Class Codes: C08L 23/0815 Copolymers of ethene with aliphatic 1-olefins
• CPC Class Codes: C08L 2314/06 Metallocene or single site catalysts
• CPC Class Codes: C08L 2666/04 Macromolecular compounds according to groups C08L7/00 - C08L49/00, or C08L55/00 - C08L57/00; Derivatives thereof
• CPC Class Codes: Y10S 526/943 Polymerization with metallocene catalysts

Abstract

Polyolefin reactor blends obtained by polymerization of ethylene and higher alpha-olefins in the presence of a catalyst system comprising two or more metallocenes and alumoxane.

Claims

1. A homogeneous catalyst system for the simultaneous production of a polymer blend in a single polymerization reactor of two or more polymers comprising homopolyethylene and an ethylene-alpha-olefin copolymer, said catalyst comprising (a) at least two different mono, di or tricyclopentadienyls and their derivatives of a Group 4b, 5b and 6b transition metal each having different reactivity ratios and (b) an alumoxane.

8. A process for the simultaneous production in a single polymerization reactor of a blend of two or more polymers comprising polyethylene and ethylene-alpha-olefin copolymer comprising polymerizing ethylene and at least one alpha-olefin simultaneously in the presence of the catalyst system of claim 1.

15. The process of claim 8 wherein the polymer blend comprises a blend of polyethylene and an ethylene-propylene copolymer.

16. The process of claim 15 wherein the polyethylene is linear low density polyethylene.

17. The process of claim 15 wherein the polyethylene is high density polyethylene.

2. A homogeneous catalyst system for the simultaneous production of a polymer blend in a single polymerization reactor of two or more polymers comprising polyethylene and an ethylene-alpha-olefin copolymer, said catalyst comprising:

(a) at least two metallocenes represented by the general formula (C₅ R'"'"'_m)_p R'"'"'_s (C₅ R'"'"'_m)MeQ_3-p or R"_s (C₅ R'"'"'_m)₂ MeQ;

each having different reactivity ratios, and

(b) and alumoxane wherein (C₅ R'"'"'_m) is a cyclopentadienyl or substituted cyclopentadienyl, each R'"'"' which can be the same or different is hydrogen or a hydrocarbyl radical such as alkyl, alkenyl, aryl, alkylaryl, or arylakyl radicals having form 1 to 20 carbon atoms or two carbon atoms are joined together to form a C₄ -C₆ ring, R" is a C₁ -C₄ alkylene radical, a dialkyl germanium or silicone, or an alkyl phosphine or amine radical bridging two (C₅ R'"'"'_m) rings, Q is a hydrocarbon radical such as aryl, alkyl, alkenyl, alkylaryl, or arylakyl radicals having from 1-20 carbon atoms or halogen and can be the same or different, Q'"'"' is an alkylidene radical having from 1 to about 20 carbon atoms, Me is a transition metal of Group 4b, 5b and 6b, s is 0 or 1, p is 0, 1 or 2, when p=0, s=0, m is 4 when s is 1, m is 5 when s is 0.

3. The catalyst system of claim 2 wherein Me is selected from zirconium and titanium.

4. The catalyst system of claim 3 wherein Q is selected from the group consisting of methyl, phenyl or chloride.

5. The catalyst system of claim 3 comprising at least 2 zirconocenes.

6. The catalyst system of claim 3 comprising at least 1 titanocenes and 1 zirconocene.

7. The catalyst system of claim 4 comprising bis(methylcyclopentadienyl) zirconium dichloride and bis(pentamethylcyclopentadiethyl)zirconium dichloride.

9. A process for producing a reactor blend comprising polymerizing ethylene and at least one alpha-olefin simultaneously in the presence of the catalyst system of claim 2.

10. A process for producing a reactor blend comprising polymerizing ethylene and at least one alpha-olefin simultaneously in the presence of the catalyst system of claim 3.

11. A process for producing a reactor blend comprising polymerizing ethylene and at least one alpha-olefin simultaneously in the presence of the catalyst system of claim 4.

12. A process for producing a reactor blend comprising polymerizing ethylene and at least one alpha-olefin simultaneously in the presence of the catalyst system of claim 5.

13. A process for producing a reactor blend comprising polymerizing ethylene and at least one alpha-olefin simultaneously in the presence of the catalyst system of claim 6.

14. A process for producing a reactor blend comprising polymerizing ethylene and at least one alpha-olefin simultaneously in the presence of the catalyst system of claim 7.