Linear polymers, polymer blends, and articles made therefrom

• US 8,247,065 B2
• Filed: 04/24/2007
• Issued: 08/21/2012
• Est. Priority Date: 05/31/2006
• Status: Active Grant

• Current Assignee: ExxonMobil Chemical Patents Inc. (Exxon Mobil Corporation)
• Original Assignee: ExxonMobil Chemical Patents Inc. (Exxon Mobil Corporation)
• Inventors: Best, Steven A., Bossaert, Bernard L., Cooke, Ronald N., German, Paul M., Graham, Blair A., Mota, Carlos A., Schram, Calvin K., Trudell, Barry C.
• Primary Examiner(s): Sample, David
• Assistant Examiner(s): KHAN, TAHSEEN
• Application Number:
  US11/789,391
• Publication Number:
  US 20080038533A1
• Time in Patent Office: 1,946 Days
• Field of Search: 428/220, 526/113, 526/348, 525/191
• US Class Current: 428/220
• CPC Class Codes: B32B 27/32 comprising polyolefins comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30
• 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 2500/08 Low density, i.e. < 0.91 g/cm3
• CPC Class Codes: C08F 2500/12 Melt flow index or melt flow ratio
• CPC Class Codes: C08F 2500/26 Use as polymer for film forming
• CPC Class Codes: C08F 4/65925 two cyclopentadienyl rings being mutually non-bridged
• CPC Class Codes: C08J 2323/08 Copolymers of ethene C08J2323/16 takes precedence
• CPC Class Codes: C08J 5/18 Manufacture of films or sheets
• CPC Class Codes: C08L 23/06 Polyethene
• CPC Class Codes: C08L 23/0815 Copolymers of ethene with aliphatic 1-olefins
• CPC Class Codes: C08L 2666/06 Homopolymers or copolymers of unsaturated hydrocarbons; Derivatives thereof

Abstract

Provided are blends of linear low density polyethylene copolymers with very low density, low density, medium density, high density, and differentiated polyethylenes and other polymers. The invention also includes articles produced from the linear low density polyethylene and polyethylene blends described herein.

Claims

1. A polymer composition comprising a blend of:

a. from about 5 to about 95 wt % of a first polymer selected from the group consisting of high density polyethylene, linear low density polyethylene, low density polyethylene, medium density polyethylene, very low density polyethylene, differentiated polyethylene, and combinations thereof; and

b. from about 95 to about 5 wt % of a second polymer comprising an ethylene-based polymer produced by gas-phase polymerization of ethylene with a catalyst having as a transition metal component a bis(n-C_3-4 alkyl cyclopentadienyl) hafnium compound, wherein said transition metal component comprises from about 95 mole % to about 99 mole % of said hafnium compound and wherein said ethylene-based polymer has;

i. a melt index of from about 0.1 g/10 min to about 300 g/10 min;

ii. a melt index ratio of from about 15 to about 45;

iii. a weight average molecular weight (M_w) of from about 20,000 to about 200,000;

iv. a molecular weight distribution (M_w/M_n) of from about 2.0 to about 4.5;

v. a M_z/M_w ratio of from about 1.7 to about 3.5; and

vi. a CDBI of from 20% to 35%; and

wherein said first polymer is different from said second polymer and wherein the composition has a Dart A Impact Strength of 850 to about 1100 g/mil and an average modulus of the MD and TD 1% Secant Moduli >

35.0 kpsi.

2. The polymer composition of claim 1, wherein said ethylene-based polymer further comprises up to about 5 mole % units derived from an alpha-olefin comonomer.

3. An article of manufacture, wherein said article comprises the polymer composition of claim 1, and wherein said article is formed by a manufacturing process selected from the group consisting of injection molding, rotational molding, blow molding, extrusion coating, foaming, casting, and combinations thereof.

4. An article of manufacture, wherein said article comprises the polymer composition of claim 1, and wherein said article is an extruded blown or cast film, or a combination thereof.

5. An article of manufacture according to claim 1, wherein said article is a non-food containing injection molded article.

6. An article of manufacture according to claim 1, wherein said article is a non-liquid containing rotomolded article.

7. The polymer composition of claim 1, wherein the second polymer has a CDBI of from 25% to 28%.

8. An article of manufacture, wherein said article comprises the polymer composition of claim 2, and wherein said article is formed by a manufacturing process selected from the group consisting of injection molding, rotational molding, blow molding, extrusion coating, foaming, casting, and combinations thereof.

9. An article of manufacture, wherein said article comprises the polymer composition of claim 2, and wherein said article is an extruded blown or cast film, or a combination thereof.

10. An article of manufacture according to claim 2, wherein said article is a non-food containing injection molded article.

11. An article of manufacture according to claim 2, wherein said article is a non-liquid containing rotomolded article.

12. An article of manufacture according to claim 4, wherein said article is an extruded monolayer film.

13. An article of manufacture according to claim 4, wherein said article is an extruded multilayer film.

14. An article of manufacture according to claim 9, wherein said article is an extruded monolayer film.

15. An article of manufacture according to claim 9, wherein said article is an extruded multilayer film.

16. A film according to claim 12, wherein the film has been downgauged by at least about 10%.

17. A film according to claim 14, wherein the film has been downgauged by at least about 10%.

18. A film according to claim 13, wherein the film has been downgauged by at least about 10%.

19. A film according to claim 15, wherein the film has been downgauged by at least about 10%.

20. A non-food containing injection molded article according to claim 5, wherein said article exhibits an improved toughness/processability balance relative to the same article made from a Ziegler-Natta catalyzed resin of substantially similar melt index and density.

21. A non-food containing injection molded article according to claim 10, wherein said article exhibits an improved toughness/processability balance relative to the same article made from a Ziegler-Natta catalyzed resin of substantially similar melt index and density.

22. A non-liquid containing rotomolded article according to claim 6, wherein said article exhibits an improved toughness/processability balance relative to the same article made from a Ziegler-Natta catalyzed resin of substantially similar melt index and density.

23. An article of manufacture according to claim 6, wherein said article is formed from powder, micropellets, or combinations thereof.

24. An article of manufacture according to claim 6, wherein said article further comprises color pigments, fillers, or combinations thereof.

25. A non-liquid containing rotomolded article according to claim 11, wherein said article exhibits an improved toughness/processability balance relative to the same article made from a Ziegler-Natta catalyzed resin of substantially similar melt index and density.

26. An article of manufacture according to claim 11, wherein said article is formed from powder, micropellets, or combinations thereof.

27. An article of manufacture according to claim 11, wherein said article further comprises color pigments, fillers, or combinations thereof.

28. A film according to claim 16, wherein the film has been downgauged by at least about 20%.

29. A film according to claim 17, wherein the film has been downgauged by at least about 20%.

30. A film according to claim 28, wherein the film has been downgauged by at least about 30%.

31. A film according to claim 29, wherein the film has been downgauged by at least about 30%.

32. A film according to claim 18, wherein the film has been downgauged by at least about 20%.

33. A film according to claim 19, wherein the film has been downgauged by at least about 20%.

34. A film according to claim 32, wherein the film has been downgauged by at least about 30%.

35. A film according to claim 33, wherein the film has been downgauged by at least about 30%.

38. The film of claim 26, wherein the film exhibits:

a Tensile MD (psi) of from about 6000 to about 9000, and

a Tensile TD (psi) of from about 5000 to about 8000, when normalized to 1 mil film thickness.

36. A film comprising a blend of:

a. from about 5 to about 95 wt % of a first polymer selected from the group consisting of high density polyethylene, linear low density polyethylene, low density polyethylene, medium density polyethylene, very low density polyethylene, differentiated polyethylene, and combinations thereof; and

b. from about 95 to about 5 wt % of a second polymer comprising at least one ethylene-based polymer produced by gas-phase polymerization of ethylene with a catalyst having as a transition metal component a bis(n-C_3-4 alkyl cyclopentadienyl) hafnium compound, wherein said transition metal component comprises from about 95 mole % to about 99 mole % of said hafnium compound and wherein said ethylene-based polymer has;

a melt index ratio of from about 20 to about 40,

a molecular weight distribution (M_w/M_n) of from about 3.0 to about 4.0,

a ratio of z-average molecular weight to weight average molecular weight of from about 2.2 to about 3.0, and

a CDBI of from 20% to 35%,

wherein the film has a Dart A Impact Strength of 850 to about 1100 g/mil and an average modulus of the MD and TD 1% Secant Moduli >

35.0 kpsi.

37. The film of claim 36, wherein the film exhibits:

a tear MD (g) of from about 200 to about 1000, and

a tear TD (g) of from about 400 to about 1000, when normalized to 1 mil film thickness.

39. The film of claim 36, wherein the second polymer has a CDBI of from 25% to 28%.