Dual metallocene bimodal HDPE resins with improved stress crack resistance

Patent metadata

Field	Value
Publication number	US-12404357-B2
Application number	US-202217575715-A
Country	US
Kind code	B2
Filing date	Jan 14, 2022
Priority date	Jan 14, 2022
Publication date	Sep 2, 2025
Grant date	Sep 2, 2025

Abstract

Ethylene-based polymers having a density from 0.94 to 0.96 g/cm 3 , a Mn from 5,000 to 14,000 g/mol, a ratio of Mw/Mn from 18 to 40, and at least one of a PENT value at 2.4 MPa of at least 11,500 hr and/or a W90 from 7.5 to 15 wt. % are disclosed. Additional ethylene polymers can have the same density, Mn, and Mw/Mn values, as well as a relaxation time from 0.5 to 3.5 sec, a CY-a parameter from 0.48 to 0.68, a HLMI from 5 to 11 g/10 min, a viscosity at HLMI from 3,000 to 7,500 Pa-sec, and a higher molecular weight component (HMW) and a lower molecular weight (LMW) component, in which a ratio of the number of SCBs at Mp of the HMW component to the number of SCBs at Mp of the LMW component is from 3.5 to 8.

First claim

We claim:

1. An ethylene polymer having:
a density in a range from 0.94 to 0.96 g/cm 3 ;
a Mn in a range from 5,000 to 14,000 g/mol;
a ratio of Mw/Mn in a range from 18 to 40; and
a PENT value at 80° C. and 2.4 MPa of at least 11,500 hr;
wherein the polymer contains from 1 to 4 long chain branches per 1,000,000 total carbon atoms.

2. An article comprising the polymer of claim 1 .

3. The polymer of claim 1 , wherein the polymer comprises an ethylene homopolymer, an ethylene/l-butene copolymer, an ethylene/l-hexene copolymer, and/or an ethylene/l-octene copolymer.

4. The polymer of claim 3 , wherein the PENT value is at least 13,500 hr.

5. The polymer of claim 4 , wherein the polymer is further characterized by:
a high load melt index (HLMI), determined at 190° C. with a 21.6 kg weight, in a range from 1 to 25 g/10 min.

6. The polymer of claim 4 , wherein:
the density is in a range from 0.942 to 0.958 g/cm 3 ;
the Mn is in a range from 6,000 to 12,000 g/mol; and
the ratio of Mw/Mn is in a range from 20 to 35.

7. The polymer of claim 4 , wherein the polymer is further characterized by:
a viscous relaxation time, according to the Carreau-Yasuda empirical model, in a range from 0.5 to 3.5 sec;
a CY-a parameter in a range from 0.48 to 0.68; and
a viscosity at 190° C. and HLMI in a range from 3,000 to 7,500 Pa-sec.

8. A pipe or blow molded product comprising the polymer of claim 1 .

9. The polymer of claim 1 , wherein the polymer is further characterized by a HLMI, determined at 190° C. with a 21.6 kg weight, in a range from 4 to 14 g/10 min.

10. The polymer of claim 1 , wherein the polymer contains, independently, less than 0.1 ppm by weight of chromium and titanium.

11. The polymer of claim 3 , wherein the polymer is further characterized by:
a viscous relaxation time, according to the Carreau-Yasuda empirical model, in a range from 0.5 to 3.5 sec;
a CY-a parameter in a range from 0.48 to 0.68;
a viscosity at 190° C. and HLMI in a range from 3,000 to 7,500 Pa-sec; or
any combination thereof.

12. An article comprising the polymer of claim 11 .

13. The polymer of claim 11 , wherein:
the density is in a range from 0.942 to 0.958 g/cm 3 ;
the Mn is in a range from 6,000 to 12,000 g/mol;
the ratio of Mw/Mn is in a range from 20 to 35; or
any combination thereof.

14. A pipe or blow molded product comprising the polymer of claim 13 .

15. The polymer of claim 11 , wherein the polymer is further characterized by:
a high load melt index (HLMI), determined at 190° C. with a 21.6 kg weight, in a range from 1 to 25 g/10 min.

16. The polymer of claim 11 , wherein the polymer has:
an IB parameter in a range from 1.8 to 2.3;
a viscosity at 190° C. and 100 sec −1 in a range from 2,200 to 2,800 Pa-sec;
a ratio at 190° C. of η @ 0.1/η @ 100 in a range from 20 to 80; and
a tan δ at 0.1 sec −1 in a range from 2.2 to 3.9 degrees.

17. The polymer of claim 11 , wherein the PENT value is at least 13,500 hr.

18. The polymer of claim 11 , wherein:
the density is in a range from 0.942 to 0.958 g/cm 3 ;
the Mn is in a range from 6,000 to 12,000 g/mol; and
the ratio of Mw/Mn is in a range from 20 to 35.

19. The polymer of claim 18 , wherein the polymer has a higher molecular weight component (HMW) and a lower molecular weight (LMW) component, a Mp of the LMW component is in a range from 10,000 to 30,000 g/mol, and a Mp of the HMW component is in a range from 400,000 to 600,000 g/mol.

20. An ethylene polymer having:
a density in a range from 0.94 to 0.96 g/cm 3 ;
a Mn in a range from 5,000 to 14,000 g/mol;
a ratio of Mw/Mn in a range from 18 to 40; and
a PENT value at 80° C. and 2.4 MPa of at least 11,500 hr;
wherein the polymer has a higher molecular weight component (HMW) and a lower molecular weight (LMW) component, and a ratio of a number of short chain branches per 1000 total carbon atoms at Mp of the HMW component to a number of short chain branches per 1000 total carbon atoms at Mp of the LMW component is in a range from 3.5 to 8.

21. An article comprising the polymer of claim 20 .

22. The polymer of claim 20 , wherein the polymer comprises an ethylene homopolymer, an ethylene/l-butene copolymer, an ethylene/l-hexene copolymer, and/or an ethylene/l-octene copolymer.

23. The polymer of claim 22 , wherein:
the PENT value is at least 13,500 hr; and
the polymer is further characterized by:
a high load melt index (HLMI), determined at 190° C. with a 21.6 kg weight, in a range from 1 to 25 g/10 min.

24. The polymer of claim 22 , wherein:
the density is in a range from 0.942 to 0.958 g/cm 3 ;
the Mn is in a range from 6,000 to 12,000 g/mol; and
the ratio of Mw/Mn is in a range from 20 to 35.

25. The polymer of claim 24 , wherein the polymer is further characterized by:
a viscous relaxation time, according to the Carreau-Yasuda empirical model, in a range from 0.5 to 3.5 sec;
a CY-a parameter in a range from 0.48 to 0.68; and
a viscosity at 190° C. and HLMI in a range from 3,000 to 7,500 Pa-sec.

26. A pipe or blow molded product comprising the polymer of claim 25 .

27. The polymer of claim 22 , wherein the polymer is further characterized by:
a high load melt index (HLMI), determined at 190° C. with a 21.6 kg weight, in a range from 1 to 25 g/10 min;
an IB parameter in a range from 1.8 to 2.3;
a viscosity at 190° C. and 100 sec −1 in a range from 2,200 to 2,800 Pa-sec;
a ratio at 190° C. of η @ 0.1/η @ 100 in a range from 20 to 80; and
a tan δ at 0.1 sec −1 in a range from 2.2 to 3.9 degrees.

28. The polymer of claim 22 , wherein the polymer contains, independently, less than 0.1 ppm by weight of chromium and titanium.

29. The polymer of claim 28 , wherein the Mp of the LMW component is in a range from 10,000 to 30,000 g/mol, and the Mp of the HMW component is in a range from 400,000 to 600,000 g/mol.

30. An article comprising the polymer of claim 29 .

Assignees

• Chevron Phillips Chemical Co Lp

Inventors

• Yu Youlu
• Yang Qing
• Sukhadia Ashish M
• Soules David A
• Praetorius Jeremy M
• Rohatgi Vivek

Classifications

• C08F10/02

  Ethene · CPC title

• C08F210/02

  Ethene · CPC title

• C08F210/18

  with non-conjugated dienes, e.g. EPT rubbers · CPC title

• C08F110/02

  Ethene · CPC title

• C08F2420/00

  Metallocene catalysts · CPC title