Thermoplastic polyolefin blends and films therefrom

1. A film comprising a composition comprising:

1) a linear ethylene containing polymer having a density of at least 0.910 g/cm 3 ; and

2) an in-reactor polymer blend comprising: (a) a first ethylene containing polymer having a density of greater than 0.90 g/cm 3 and a M w of more than 20,000 g/mol and (b) a second ethylene containing polymer having a density of less than 0.90 g/cm 3 , wherein the densities of the first and second polymers differ by at least 1%, and wherein the in-reactor polymer blend has a T m of at least 90° C. (DSC second melt), a density of less than 0.92 g/cm 3 , and contains at least 78 wt % ethylene.

2. The film of claim 1 , wherein the linear ethylene containing polymer has a CDBI of 60% or more.

3. The film of claim 1 , wherein the linear ethylene containing polymer is an LLDPE or an HDPE.

4. The film of claim 1 , wherein the linear ethylene containing polymer has an M w of 50,000 g/mol or more, a g′ of 0.95 or more and an M w /M n of from greater than 1 to 10 and comprises from 50 mole % to 100 mole % ethylene and from 0 mole % to 50 mole % of C 3 to C 40 comonomer.

5. The film of claim 1 , wherein the linear ethylene containing polymer is a polymer of an ethylene and at least one alpha olefin having 5 to 20 carbon atoms, where the linear ethylene containing polymer has a melt index (190° C./2.16 kg) of from 0.1 to 15 dg/min; a CDBI of at least 70%, a density of from 0.910 to 0.930 g/cm 3 ; a haze value of less than 20; a melt index ratio of from 35 to 80; an averaged modulus (M) of from 20000 to 60000 psi and a relation between M and the dart impact strength in g/mil, DIS, complying with the formula:

DIS≧0.8[100+exp(11.71−0.000268M+2.183×10 −9 M 2 )].

6. The film of claim 1 , wherein the linear ethylene containing polymer has a density of 0.940 g/cm 3 or more.

7. A film comprising a composition comprising:

1) a linear ethylene containing polymer having a density of at least 0.910 g/cm 3 ; and

2) at least 1 wt % of an in-reactor polymer blend comprising: (a) a first ethylene polymer comprising 90 wt % to 100 wt % ethylene and from 0 wt % to less than 10 wt % comonomer, said first ethylene polymer component having density of greater than 0.920 g/cm 3 and an M w of 20,000 g/mol or more; and (b) a second ethylene polymer comprising from 70 wt % to 90 wt % ethylene and 30 wt % to 10 wt % comonomer, said second ethylene polymer having a density of 0.910 g/cm 3 or less, wherein the in-reactor polymer blend has:

(a) at least 78 wt % ethylene;

(b) a T m of at least 100° C. over a density ranging from 0.84 to 0.92 g/cm 3 ;

(c) an elongation at break of 300% or more;

(d) a strain hardening ratio, M300/M100, of at least 1.2;

(e) a ratio of complex viscosity at 0.01 rad/s to the complex viscosity at 100 rad/s of at least 30; and

(f) a shear thinning index of less than −0.2.

8. The film of claim 7 , wherein the difference in density between the first ethylene polymer and the second ethylene polymer is at least 1%.

9. The film of claim 7 , wherein the first ethylene polymer has a T m of 110° C. or more.

10. The film of claim 7 , wherein the in-reactor blend has a density from 0.84 to 0.92 g/cm 3 and a melting point of from 100° C. to 130° C.

11. The film of claim 7 , wherein the in-reactor blend has a strain hardening index M500/M100 of at least 1.2.

12. The film of claim 7 , wherein the in-reactor blend has a heat of fusion of at least 50 J/g.

13. The film of claim 7 , wherein the in-reactor blend has a tensile strength of greater than 15 MPa.

14. The film of claim 7 , wherein the in-reactor blend has an elongation at break of greater than 400%.

15. The film of claim 7 , wherein the in-reactor blend has a tensile toughness of 40 MJ/m 3 or more.

16. The film of claim 7 , wherein the in-reactor blend has a melt index at 190° C., under a 2.16 kg load, of 0.01 to 100 dg/min.

17. The film of claim 7 , wherein the first ethylene containing polymer of the in-reactor blend has 95 wt % to 100 wt % ethylene and 0 wt % to 5 wt % comonomer selected from the group consisting of propylene, butene, hexene or octene.

18. The film of claim 7 , wherein the second ethylene containing polymer of the in-reactor blend has 70 wt % to 90 wt % ethylene and 10 wt % to 30 wt % comonomer selected from the group consisting of propylene, butene, hexene or octene.

19. The film of claim 7 , wherein the first ethylene containing polymer of the in-reactor blend has a melting point of 110° C. or more and a melt index at 190° C., under a 2.16 kg load, of 0.01 to 800 dg/min, and the second ethylene containing polymer of the in-reactor blend has a melt index at 190° C., under a 2.16 kg load of 200 dg/min or less.

20. The film of claim 7 , wherein the second ethylene containing polymer of the in-reactor blend has a 1% secant flexural modulus from 5 to 100 MPa.

21. The film of claim 7 , wherein the in-reactor polymer blend has a cyclohexane refluxing insoluble fraction of 70 wt % or less.

22. The film of claim 7 , wherein the linear ethylene containing polymer has a CDBI of 60% or more.

23. The film of claim 7 , wherein the linear ethylene containing polymer is an LLDPE or an HDPE.

24. The film of claim 7 , wherein the linear ethylene containing polymer has an M w of 50,000 g/mol or more, a g′ of 0.95 or more and an M w /M n of from greater than 1 to 10 and comprises from 50 mole % to 100 mole % ethylene and from 0 mole % to 50 mole % of C 2 to C 40 comonomer.

25. The film of claim 7 , wherein the linear ethylene containing polymer is a polymer of an ethylene and at least one alpha olefin having 5 to 20 carbon atoms, where the linear ethylene containing polymer has a melt index (190° C./2.16 kg) of from 0.1 to 15 dg/min; a CDBI of at least 70%, a density of from 0.910 to 0.930 g/cm 3 ; a haze value of less than 20; a melt index ratio of from 35 to 80; an averaged modulus (M) of from 20000 to 60000 psi and a relation between M and the dart impact strength in g/mil, DIS, complying with the formula:

DIS≧0.8[100+exp(11.71−0.000268M+2.183×10 −9 M 2 )].

26. The film of claim 7 , wherein the linear ethylene containing polymer has a density of 0.940 g/cm 3 or more.

27. A process to produce a film comprising a blend of a linear ethylene containing polymer and an in-reactor blend comprising:

1) preparing an in-reactor blend by contacting a metallocene catalyst compound and an activator with ethylene, comonomer, and a macromonomer having at least 50% vinyl terminal unsaturation based on the total unsaturated olefin chain ends, where the macromonomer has an M w of 20,000 g/mol or more, a density of 0.920 g/cm 3 or more, and optionally a melting point of 110° C. or more;

2) obtaining an in-reactor blend comprising:

(a) a first ethylene polymer comprising 90 wt % to 100 wt % ethylene and from 0 wt % to less than 10 wt % comonomer, said first ethylene polymer component having density of greater than 0.920 g/cm 3 and an M w of 20,000 g/mol or more; and

(b) a second ethylene polymer comprising from 70 wt % to 90 wt % ethylene and 30 wt % to 10 wt % comonomer, said second ethylene polymer having a density of 0.910 g/cm 3 or less;

wherein the in-reactor polymer blend has:

(a) at least 78 wt % ethylene;

(b) a T m of at least 100° C. over a density ranging from 0.84 to 0.92 g/cm 3 ;

(c) an elongation at break of 300% or more;

(d) a strain hardening ratio, M300/M100, of at least 1.2;

(e) a ratio of complex viscosity at 0.01 rad/s to the complex viscosity at 100 rad/s of at least 30; and

(f) a shear thinning index of less than −0.2;

3) combining at least 1 wt % of the in-reactor blend with a linear ethylene containing polymer having a density of at least 0.910 g/cm 3 ;

4) converting the combination of in-reactor blend with a linear ethylene containing polymer into a film.

28. The process of claim 27 , wherein the process to produce the in-reactor blend occurs in the solution phase.

29. The process of claim 27 , wherein the process to produce the in-reactor blend occurs in the gas or slurry phase.

30. The process of claim 27 , wherein the macromonomer is made in the same reactor as the in-reactor blend.

31. The process of claim 27 , where the process to produce the in-reactor blend comprises:

(i) contacting at least one first monomer composition comprising ethylene with a first catalyst capable of producing ethylene polymer having a density of 0.920 g/cm 3 or more and an M w of 20,000 g/mol or more at the selected polymerization conditions in a first polymerization stage under conditions including a first temperature sufficient to produce the ethylene-containing first polymer comprising at least 50% vinyl chain ends; and

(ii) contacting at least part of said first polymer with a second monomer composition comprising ethylene and comonomer and with a second catalyst capable of producing polymer having a density of 0.910 g/cm 3 or less or more in a second polymerization stage under conditions including a second temperature sufficient to polymerize said second monomer composition to produce the ethylene-containing second polymer.

32. The film of claim 7 , wherein the composition has a decrease in the phase angle (δ) at a complex modulus of 10 kPa at 190° C. of at least 0.3° per wt % of the in-reactor polymer blend added relative to the linear ethylene containing polymer.

33. The film of claim 32 , wherein the composition is a homogenous polymeric blend having an increase in the degree of shear thinning at 190° C. of at least 0.002 per 1 wt % of the in-reactor polymer blend added relative to the linear ethylene containing polymer.

34. The film of claim 1 , wherein the film has one or more of the following properties:

(a) a 1% secant modulus (MD) of at least 25,000 psi;

(b) a 1% secant modulus (TD) of at least 24,000 psi;

(c) a yield strength (both MD and TD) of at least 900 psi;

(d) an elongation at yield (both MD and TD) of at least 4.0%;

(e) a tensile strength in MD of at least 6.500 psi;

(f) an Elmendorf tear in MD of at least 180 g/mil;

(g) a dart drop impact of at least 200 g/mil;

(h) a Haze lower than 65%; and

(i) a gauge COV lower than 10.0%.

35. The film of claim 1 , wherein the film is a cast film.

36. The film of claim 1 , wherein the film is a blown film.

37. The film of claim 1 , wherein the film is a an oriented film.

38. The film of claim 1 , wherein the film is 1 to 100 microns thick.

39. The film of claim 1 , wherein the film is 2 to 50 microns thick.

40. The film of claim 1 , wherein the film is 10 to 30 microns thick.

41. The film of claim 1 , wherein the in-reactor polymer blend is present at from 1 to 5 wt %, based upon the weight of the blend.

42. The film of claim 1 , wherein the film has the following properties:

(a) a 1% secant modulus (MD) of at least 25,000 psi;

(b) a 1% secant modulus (TD) of at least 24,000 psi;

(c) a yield strength (both MD and TD) of at least 900 psi;

(d) an elongation at yield (both MD and TD) of at least 4.0%;

(e) a tensile strength in MD of at least 6.500 psi;

(f) an Elmendorf tear in MD of at least 180 g/mil;

(g) a dart drop impact of at least 200 g/mil;

(h) a Haze lower than 65%; and

(i) a gauge COV lower than 10.0%.

43. A molded article comprising a composition comprising:

1) a linear ethylene containing polymer having a density of at least 0.910 g/cm 3 ; and

2) an in-reactor polymer blend comprising: (a) a first ethylene containing polymer having a density of greater than 0.90 g/cm 3 and a M w of more than 20,000 g/mol and (b) a second ethylene containing polymer having a density of less than 0.90 g/cm 3 , wherein the densities of the first and second polymers differ by at least 1%, and wherein the in-reactor polymer blend has a T m of at least 90° C. (DSC second melt), a density of less than 0.92 g/cm 3 , and contains at least 78 wt % ethylene.

44. A molded article comprising a composition comprising:

1) a linear ethylene containing polymer having a density of at least 0.910 g/cm 3 ; and

2) at least 1 wt % of an in-reactor polymer blend comprising: (a) a first ethylene polymer comprising 90 wt % to 100 wt % ethylene and from 0 wt % to less than 10 wt % comonomer, said first ethylene polymer component having density of greater than 0.920 g/cm 3 and an M w of 20,000 g/mol or more; and (b) a second ethylene polymer comprising from 70 wt % to 90 wt % ethylene and 30 wt % to 10 wt % comonomer, said second ethylene polymer having a density of 0.910 g/cm 3 or less, wherein the in-reactor polymer blend has:

(a) at least 78 wt % ethylene;

(b) a T m of at least 100° C. over a density ranging from 0.84 to 0.92 g/cm 3 ;

(c) an elongation at break of 300% or more;

(d) a strain hardening ratio, M300/M100, of at least 1.2;

(e) a ratio of complex viscosity at 0.01 rad/s to the complex viscosity at 100 rad/s of at least 30; and

(f) a shear thinning index of less than −0.2.

45. The film of claim 1 , wherein the film has a gauge COV lower than 7.0%.