Ethylene/1-butene copolymers with enhanced resin processability

Patent metadata

Field	Value
Publication number	US-9815925-B2
Application number	US-201615163266-A
Country	US
Kind code	B2
Filing date	May 24, 2016
Priority date	May 27, 2015
Publication date	Nov 14, 2017
Grant date	Nov 14, 2017

Abstract

Ethylene/1-butene copolymers made with a single site catalyst system have high melt strength and good processability.

First claim

What is claimed is:

1. An ethylene copolymer made by polymerizing ethylene and 1-butene with a single site catalyst system in a polymerization reactor, the ethylene copolymer having a density of from 0.912 to 0.94 g/cm 3 , a melt index (I 2 ) of from 0.5 to 10 g/10 min, a melt flow ratio (I 21 /I 2 ) of from 20 to 35, a molecular weight distribution (M w /M n ) of from 2.0 to 4.5, a shear thinning index of 0.75 or less, and an accelerated haul-off melt, strength (σ MS ) as determined by Rosand capillary rheometry at 190° C., of at least 3.0 cN.

2. The ethylene copolymer of claim 1 having a CY a parameter of 0.40 or less.

3. The ethylene copolymer of claim 1 which satisfies the following relationship:
(CDBI 50 /δ XO ) 3.0 ≦6.5−5.7 Log [ a (1.5( I 21 /I 2 )+( M w /M n ))];

where CDBI 50 is the composition distribution breadth index, δ XO is the crossover phase angle at a frequency of 1.0 rad/s and a is the CY a parameter.

4. The ethylene copolymer of claim 1 further satisfying the relationship:
σ MS ≧5.0×10 −4 ×G* XO ;

where σ MS is the accelerated haul-off melt strength determined at 190° C.; and G* XO is the crossover complex modulus at a frequency of 1.0 rad/s.

5. The ethylene copolymer of claim 3 further satisfying the relationship:
σ MS ≧5.0×10 −4 ×G* XO ;

where σ MS is the accelerated haul-off melt strength determined at 190° C.; and G* XO is the crossover complex modulus at a frequency of 1.0 rad/s.

6. A film structure comprising a film layer made from an ethylene/1-butene copolymer wherein the ethylene/1-butene copolymer is made by polymerizing ethylene and 1-butene with a single site catalyst system in a polymerization reactor, the ethylene/1-butene copolymer having density of from 0.912 to 0.94 g/cm 3 , a melt index (I 2 ) of from 0.5 to 10 g/10 min, a melt flow ratio (I 21 /I 2 ) of from 20 to 35, a molecular weight distribution (M w /M n ) of from 2.0 to 4.5, a shear thinning index of 0.75 or less, and an accelerated haul-off melt strength (σ MS ) as determined by Rosand capillary rheometry at 190° C., of at least 3.0 cN.

7. An ethylene copolymer made by polymerizing ethylene and 1-butene with a single site catalyst system in a polymerization reactor, the ethylene copolymer having density of from 0.912 to 0.94 g/cm 3 , a melt index (I 2 ) of from 0.5 to 10 g/10 min, a melt flow ratio (I 21 /I 2 ) of from 20 to 35, a molecular weight distribution (M w /M n ) of from 2.0 to 4.5, and which satisfies the following relationship:
(CDBI 50 /δ XO ) 3.0 ≦6.5−5.7 log [ a (1.5( I 21 /I 2 )+( M w /M n ))];

where CDBI 50 is the composition distribution breadth index, δ XO is the crossover phase angle at a frequency of 1.0 rad/s and a is the CY a parameter.

8. The ethylene copolymer of claim 7 further satisfying the relationship:
σ MS ≧5.0×10 −4 ×G* XO ;

where σ MS is the accelerated haul-off melt strength determined at 190° C.; and G* XO is the crossover complex modulus at a frequency of 1.0 rad/s.

9. A film structure comprising a film layer made from an ethylene/1-butene copolymer wherein the ethylene/1-butene copolymer is made by polymerizing ethylene and 1-butene with a single site catalyst system in a polymerization reactor, the ethylene/1-butene copolymer having density of from 0.912 to 0.94 g/cm 3 , a melt index (I 2 ) of from 0.5 to 10 g/10 min, a melt flow ratio (I 21 /I 2 ) of from 20 to 35, a molecular weight distribution (M w /M n ) of from 2.0 to 4.5, and which satisfies the following relationship:
(CDBI 50 /δ XO ) 3.0 ≦6.5−5.7 log [ a (1.5( I 21 /I 2 )+( M w /M n ))];

where CDBI 50 is the composition distribution breadth index, δ XO is the crossover phase angle at a frequency of 1.0 rad/s and a is the CY a parameter.

10. An ethylene copolymer made by polymerizing ethylene and 1-butene with a single site catalyst system in a polymerization reactor, the ethylene copolymer having a density of from 0.912 to 0.94 g/cm 3 , a melt index (I 2 ) of from 0.5 to 10 g/10 min, a melt flow ratio (I 21 /I 2 ) of from 20 to 35, a molecular weight distribution (M w /M n ) of from 2.0 to 4.5, a shear thinning index of 0.75 or less, a CY a parameter of 0.40 or less, an accelerated haul-off melt strength (σ MS ) as determined by Rosand capillary rheometry at 190° C., of at least 3.0 cN and which satisfies the following relationship:
(CDBI 50 /δ XO ) 3.0 ≦6.5−5.7 log [ a (1.5( I 21 /I 2 )+( M w /M n ))];

where CDBI 50 is the composition distribution breadth index, δ XO is the crossover phase angle at a frequency of 1.0 rad/s and a is the CY a parameter.

11. The ethylene copolymer of claim 10 further satisfying the relationship:
σ MS ≧5.0×10 −4 ×G* XO ;

where σ MS is the accelerated haul-off melt strength determined at 190° C.; and G* XO is the crossover complex modulus at a frequency of 1.0 rad/s.

12. A film structure comprising a film layer made from an ethylene/1-butene copolymer wherein the ethylene/1-butene copolymer is made by polymerizing ethylene and 1-butene with a single site catalyst system in a polymerization reactor, the ethylene copolymer having a density of from 0.912 to 0.94 g/cm 3 , a melt index (I 2 ) of from 0.5 to 10 g/10 min, a melt flow ratio (I 21 /I 2 ) of from 20 to 35, a molecular weight distribution (M w /M n ) of from 2.0 to 4.5, a shear thinning index of 0.75 or less, a CY a parameter of 0.40 or less, an accelerated haul-off melt strength (σ MS ) as determined by Rosand capillary rheometry at 190° C., of at least 3.0 cN and which satisfies the following relationship:
(CDBI 50 /δ XO ) 3.0 ≦6.5−5.7 log [ a (1.5( I 21 /I 2 )+( M w /M n ))];

where CDBI 50 is the composition distribution breadth index, δ XO is the crossover phase angle at a frequency of 1.0 rad/s and a is the CY a parameter.

13. The film structure of claim 12 wherein the ethylene/1-butene copolymer further satisfies the relationship:
σ MS ≧5.0×10 −4 ×G* XO ;

where σ MS is the accelerated haul-off melt strength determined at 190° C.; and G* XO is the crossover complex modulus at a frequency of 1.0 rad/s.

Assignees

• Nova Chemicals International Sa

Inventors

• Lam Patrick
• Ker Victoria
• Quaiattini Robert

Classifications

• C08F210/16 Primary

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

• C08J5/18

  Manufacture of films or sheets · CPC title

• C08F210/08

  Butenes · CPC title

• C08F2500/06

  Comonomer distribution, e.g. normal, reverse or narrow · CPC title

• C08F2500/26

  Use as polymer for film forming · CPC title