Polymers with improved toughness and ESCR for large-part blow molding applications

Patent metadata

Field	Value
Publication number	US-9273170-B2
Application number	US-201414205422-A
Country	US
Kind code	B2
Filing date	Mar 12, 2014
Priority date	Mar 12, 2014
Publication date	Mar 1, 2016
Grant date	Mar 1, 2016

Abstract

Disclosed herein are ethylene-based polymers having a density greater than 0.945 g/cm 3 , a high load melt index less than 25 g/10 min, a peak molecular weight ranging from 52,000 to 132,000 g/mol, and an environmental stress crack resistance of at least 250 hours. These polymers have the processability of chromium-based resins, but with improved impact strength and stress crack resistance, and can be used in large-part blow molding applications.

First claim

The invention claimed is:

1. An ethylene polymer having a density of greater than or equal to about 0.945 g/cm 3 , a high load melt index (HLMI) in a range from about 1 to about 25 g/10 min, a peak molecular weight (Mp) in a range from about 52,000 to about 132,000 g/mol, a Mn in a range from about 30,000 to about 60,000 g/mol, a Mz in a range from about 1,750,000 to about 4,000,000 g/mol, a ratio of Mw/Mn in a range from about 5 to about 22, less than about 0.008 long chain branches per 1000 total carbon atoms, and an environmental stress crack resistance (ESCR) of at least 250 hours.

2. The polymer of claim 1 , wherein the ethylene polymer has:
a Mn in a range from about 30,000 to about 55,000 g/mol; and
a ratio of Mw/Mn in a range from about 6 to about 18.

3. The polymer of claim 1 , wherein the ethylene polymer has:
a zero-shear viscosity in a range from about 5×10 5 to about 1×10 9 Pa-sec; and
a viscosity at 100 sec −1 in a range from about 2000 to about 4000 Pa-sec.

4. The polymer of claim 1 , wherein the ethylene polymer has:
a density in a range from about 0.95 to about 0.965 g/cm 3 ;
a HLMI in a range from about 1 to about 20 g/10 min;
a Mp in a range from about 60,000 to about 120,000 g/mol; and
an ESCR of at least 1000 hours.

5. The polymer of claim 1 , wherein the ethylene polymer has:
a number of short chain branches per 1000 total carbon atoms at Mz that is greater than at Mn.

6. The polymer of claim 1 , wherein the ethylene polymer has a bimodal molecular weight distribution.

7. The polymer of claim 1 , wherein the ethylene polymer has:
a Tensile Impact greater than or equal to about 450 kJ/m 2 ; and
a Charpy Impact in a range from about 25 to about 75 kJ/m 2 .

8. The polymer of claim 1 , wherein the ethylene polymer is an ethylene/1-butene copolymer, an ethylene/1-hexene copolymer, or an ethylene/1-octene copolymer.

9. An article comprising the ethylene polymer of claim 1 .

10. A blow molded article comprising the ethylene polymer of claim 1 .

11. An ethylene polymer having a density of greater than or equal to about 0.945 g/cm 3 , a high load melt index (HLMI) in a range from about 2 to about 20 g/10 min, a viscosity at 100 sec −1 in a range from about 2000 to about 4000 Pa-sec, a weight-average molecular weight (Mw) in a range from about 275,000 to about 800,000 g/mol, a number-average molecular weight (Mn) in a range from about 30,000 to about 60,000 g/mol, and a ratio of Mw/Mn in a range from about 5 to about 22.

12. The polymer of claim 11 , wherein the ethylene polymer has:
a zero-shear viscosity in a range from about 5×10 5 to about 1×10 9 Pa-sec; and
a viscosity at 100 sec −1 in a range from about 2000 to about 3800 Pa-sec.

13. The polymer of claim 11 , wherein the ethylene polymer has:
a density in a range from about 0.95 to about 0.965 g/cm 3 ;
a Mw in a range from about 375,000 to about 650,000 g/mol; and
a Mp in a range from about 65,000 to about 115,000 g/mol.

14. The polymer of claim 11 , wherein the ethylene polymer has an ESCR of at least 1000 hours.

15. The polymer of claim 11 , wherein the ethylene polymer has:
a bimodal molecular weight distribution;
less than about 0.008 long chain branches per 1000 total carbon atoms; and
a number of short chain branches per 1000 total carbon atoms at Mz that is greater than at Mn.

16. The polymer of claim 11 , wherein the ethylene polymer is an ethylene/1-butene copolymer, an ethylene/1-hexene copolymer, or an ethylene/1-octene copolymer.

17. An article comprising the ethylene polymer of claim 11 .

18. The polymer of claim 1 , wherein the ethylene polymer is an ethylene homopolymer.

19. The polymer of claim 1 , wherein the ethylene polymer is an ethylene/1-hexene copolymer.

20. The polymer of claim 11 , wherein the ethylene polymer is an ethylene homopolymer.

21. The polymer of claim 11 , wherein the ethylene polymer is an ethylene/1-hexene copolymer.

Assignees

• Chevron Phillips Chemical Co

Inventors

• Hlavinka Mark L
• Yang Qing
• Inn Yongwoo
• Whitte William M
• Rathman John R
• Secora Steven J
• Hert Daniel G

Classifications

• C08F4/65904

  in combination with another component of C08F4/64 · CPC title

• C08F210/16 Primary

  Copolymers of ethene with alpha-alkenes, e.g. EP rubbers · CPC title

• C08F4/65916

  supported on a carrier, e.g. silica, MgCl2, polymer · CPC title

• C08L23/0815

  with aliphatic 1-olefins containing one carbon-to-carbon double bond · CPC title

• C08F2500/07

  High density, i.e. > 0.95 g/cm3 · CPC title