POLYMER RESINS WITH IMPROVED PROCESSABILITY AND MELT FRACTURE CHARACTERISTICS

• US 20140242314A1
• Filed: 02/27/2013
• Published: 08/28/2014
• Est. Priority Date: 02/27/2013
• Status: Active Grant

• Current Assignee: Chevron Phillips Chemical Company LP (Chevron Corp.)
• Original Assignee: Chevron Phillips Chemical Company LP (Chevron Corp.)
• Inventors: YANG, Qing, INN, Yongwoo
• Granted Patent: US 8,815,357 B1
• Time in Patent Office: Days
• US Class Current: 428/36.9
• CPC Class Codes: B32B 1/08 Tubular products
• 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 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 2410/04 Dual catalyst, i.e. use of two different catalysts, where none of the catalysts is a metallocene
• CPC Class Codes: C08F 2410/07 Catalyst support treated by an anion, e.g. Cl-, F-, SO42-
• CPC Class Codes: C08F 2500/01 High molecular weight, e.g. >800,000 Da.
• CPC Class Codes: C08F 2500/02 Low molecular weight, e.g. <100,000 Da.
• CPC Class Codes: C08F 2500/04 Broad molecular weight distribution, i.e. Mw/Mn > 6
• CPC Class Codes: C08F 2500/05 Bimodal or multimodal molecular weight distribution
• CPC Class Codes: C08F 2500/09 Long chain branches
• CPC Class Codes: C08F 2500/10 Short chain branches
• 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 2500/17 Viscosity
• CPC Class Codes: C08F 2500/26 Use as polymer for film forming
• 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 4/65925 two cyclopentadienyl rings being mutually non-bridged
• CPC Class Codes: C08F 4/65927 : two cyclopentadienyl rings being mutually bridged
• CPC Class Codes: C08L 23/04 : Homopolymers or copolymers of ethene
• CPC Class Codes: Y10T 428/1352 : Polymer or resin containing [i.e., natural or synthetic]
• CPC Class Codes: Y10T 428/139 : Open-ended, self-supporting conduit, cylinder, or tube-type article

Abstract

A metallocene-catalyzed polymer comprising (i) a higher molecular weight component and (ii) a lower molecular weight component wherein the polymer has a polydispersity index of from about 10 to about 26; a zero shear viscosity of from about 5×10⁵ Pa·s to about 2×10¹⁴ Pa·s and a smooth-to-matte transition critical stress of from about 20 kPa to about 85 kPa at a shear rate of from about 1.5 s⁻¹ to about 17 s⁻¹. A dual metallocene catalyzed polyethylene comprising (i) a higher molecular weight component and (ii) a lower molecular weight component wherein the polymer has a polydispersity index of from about 10 to about 26; a zero shear viscosity of from about 5×10⁵ Pa·s to about 2×10¹⁴ Pa·s and a smooth-to-matte transition stress of from about 20 kPa to about 85 kPa at a shear rate of from about 1.5 s⁻¹ to about 17 s⁻¹.

Claims

1. A metallocene-catalyzed polymer comprising (i) a higher molecular weight component and (ii) a lower molecular weight component wherein the polymer has a polydispersity index of from about 10 to about 26;

a zero shear viscosity of from about 5×

10⁵ Pa·

s to about 2×

10¹⁴ Pa·

s and a smooth-to-matte transition critical stress of from about 20 kPa to about 85 kPa at a shear rate of from about 1.5 s<sup>−

1</sup> to about 17 s<sup>−

1</sup>.

2. The polymer of claim 1 wherein the higher molecular weight component is present in an amount of from about 3 wt. % to about 30 wt. %.

3. The polymer of claim 1 wherein the lower molecular weight component is present in an amount of from about 70 wt. % to about 97 wt. %.

4. The polymer of claim 1 having a weight average molecular weight of from about 260 kg/mol to about 350 kg/mol.

5. The polymer of claim 1 having a number average molecular weight of from about 12 kg/mol to about 26 kg/mol.

6. The polymer of claim 1 having a z-average molecular weight of from about 1500 kg/mol to about 2500 kg/mol.

7. The polymer of claim 1 having a short-chain branching content of from about 0.5 SCB/1000 C. to about 3.5 SCB/1000 C. wherein from about 50% to about 80% of the short chain branches are located in the higher molecular weight component.

8. The polymer of claim 1 having a long-chain branching content of from about 0.002 branches per 1000 carbon to about 0.2 branches per 1000 carbon.

9. The polymer of claim 1 having a high load melt index of from about 5 to about 12.

10. The polymer of claim 1 having a CY-a parameter of from about 0.03 to about 0.4.

11. The polymer of claim 1 having a tau eta value of from about 7 s to about 2.0×

10⁵ s.

12. The polymer of claim 1 having a magnitude of slip-stick fracture of from about 200 psi to about 1200 psi.

13. The polymer of claim 1 having an N_—

100 value of from about 0.2 to about 0.5.

14. The polymer of claim 1 having a viscosity at 100 rad/s of from 2×

10³ Pa·

s to about 2.4×

10³ Pa·

s.

15. A composition comprising the polymer of claim 1 and a polymer processing aid.

16. The composition of claim 15 wherein the polymer processing aid comprises fluoroelastomers, polyethylene glycol, low molecular weight waxes, or combinations thereof.

17. An article made from the polymer of claim 1.

18. An article made from the composition of claim 15.

22. The polymer of claim 1 wherein the polymer is a copolymer of ethylene and 1-hexene.

19. A dual metallocene catalyzed polyethylene comprising (i) a higher molecular weight component and (ii) a lower molecular weight component wherein the polymer has a polydispersity index of from about 10 to about 26;

a zero shear viscosity of from about 5×

10⁵ Pa·

s to about 2×

10¹⁴ Pa·

s and a smooth-to-matte transition stress of from about 20 kPa to about 85 kPa at a shear rate of from about 1.5 s<sup>−

1</sup> to about 17 s<sup>−

1</sup>.

20. A composition comprising the dual metallocene catalyzed polyethylene of claim 19 and a fluoroelastomer.

21. A pipe made from the composition of claim 20.