Mixed catalysts and their use in a polymerization process

• US 6,207,606 B1
• Filed: 05/15/1998
• Issued: 03/27/2001
• Est. Priority Date: 05/15/1998
• Status: Expired due to Term

• Current Assignee: Univation Technologies LLC (Dow, Inc.)
• Original Assignee: Univation Technologies LLC (Dow, Inc.)
• Inventors: Lue, Ching-Tai, Crowther, Donna J.
• Primary Examiner(s): Bell, Mark L.
• Assistant Examiner(s): PASTERCZYK, JAMES W
• Application Number:
  US09/079,743
• Time in Patent Office: 1,047 Days
• Field of Search: 502/103, 502/104, 502/113, 502/117, 502/152, 502/153
• US Class Current: 502/113
• CPC Class Codes: C08F 210/02 Ethene
• CPC Class Codes: C08F 210/14 Monomers containing five or more carbon atoms
• CPC Class Codes: C08F 210/16 Copolymers of ethene with alpha-alkenes, e.g. EP rubbers
• CPC Class Codes: C08F 2500/04 Broad molecular weight distribution, i.e. Mw/Mn > 6
• CPC Class Codes: C08F 2500/11 Melt tension or melt strength
• CPC Class Codes: C08F 2500/12 Melt flow index or melt flow ratio
• CPC Class Codes: C08F 2500/14 Die swell or die swell ratio or swell ratio
• CPC Class Codes: C08F 2500/18 Bulk density
• 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 4/65916 supported on a carrier, e.g. silica, MgCl2, polymer
• CPC Class Codes: C08F 4/65927 two cyclopentadienyl rings being mutually bridged
• CPC Class Codes: Y10S 526/943 Polymerization with metallocene catalysts

Abstract

The present invention relates to a mixed catalyst system of at least one bridged, bulky ligand metallocene-type compound, and at least one bridged, asymmetrically substituted, bulky ligand metallocene-type compound, a method of making the mixed catalyst system and to its use in a polymerization process to produce olefin polymers having an unexpected improvement in processability.

Claims

1. A mixed catalyst comprising a metallocene catalyst activator and at least with two different metallocenes, two bulky ligands on each metallocene being bridged to each other, and wherein the at least two metallocenes each comprise a transition metal, which is the same or different, from Group 3 to 7 or a metal of the Lanthanide or Actinide Series of the Periodic Table of Elements, wherein at least one metallocene comprises at least two bridged bulky ligands, the number of non-hydrogen substituents, said substituent beings the same or different on each of the bulky ligands, being from 0 to 4, said number being the same;

the number of substituents on each of the bulky ligands of the at least one other metallocene being different, the bulky ligands are the same and the substituents are the same or different.

2. The mixed catalyst composition in accordance with claim 1 wherein the mixed catalyst comprises from 2 to 98 mole percent of the one metallocene from 98 to 2 mole percent of the at least one other metallocene based on the total mole percent of the one metallocene and the one other metallocene.

3. The mixed catalyst in accordance with claim 1 wherein the mixed catalyst comprises from 5 to 95 mole percent of the one metallocene to from 95 to 5 mole percent of the at least one other metallocene based on the total mole percent of the one metallocene and the one other metallocene.

4. The mixed catalyst in accordance with claim 1 wherein the mixed catalyst comprises a carrier.

5. The mixed catalyst in accordance with claim 1 wherein the one metallocene compound is represented by the formula:

6. The mixed catalyst in accordance with claim 5 wherein integer d is 0 or 2.

7. A method for making a supported mixed catalyst, the method comprising the steps of:

(a) mixing the one metallocene and the one other metallocene of claim 1 to form a catalyst mixture;

(b) contacting the catalyst mixture with a carrier, and

(c) introducing an activator.

8. The method in accordance with claims 7 wherein the supported mixed catalyst comprises from 2 to 98 mole percent of the one metallocene to from 98 to 2 mole percent of the at least one other metallocene based on the total mole percent of the one metallocene and the one other metallocene.

9. A method of making a supported mixed catalyst comprising combining (a) the one metallocene of claim 1;

(b) the one other metallocene of claim 1 (c) at least one activator; and

(d) at least one carrier.

10. The method in accordance with claim 9 wherein (a) and (b) are combined prior to combining with (c).

11. The method in accordance with claim 9 wherein (a), (b) and (c) are combined prior to combining with (d).

12. The method in accordance with claim 9 wherein (a) is in the range of from about 85 to about 15 mole percent based on the total moles of (a) and (b).

13. The method in accordance with claim 9 wherein (b) is in the range of from about 75 to about 25 mole percent based on the total moles of (a) and (b).