Ethylene/1-butene copolymers with enhanced resin processability

Patent metadata

Field	Value
Publication number	US-10370469-B2
Application number	US-201715720233-A
Country	US
Kind code	B2
Filing date	Sep 29, 2017
Priority date	May 27, 2015
Publication date	Aug 6, 2019
Grant date	Aug 6, 2019

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. A process for making an ethylene/1-butene copolymer, the process comprising polymerizing ethylene and 1-butene with a single site catalyst system in a gas phase polymerization reactor, wherein the ethylene/1-butene copolymer has density of from 0.912 to 0.94 g/cm 3 , a melt index (12) of from 0.5 to 10 g/10 min, a melt flow ratio (121/12) of from 20 to 35, a molecular weight distribution (M w /M n ) of from 2.0 to 4.5, and an accelerated haul-off melt strength (σ MS ) as determined by Rosand capillary rheometry at 190° C., of at least 3.0 cN; wherein the single site catalyst system comprises a phosphinimine catalyst, a cocatalyst and an inert support.

2. The process of claim 1 wherein the phosphinimine catalyst has the formula:
(1-R ¥ -Indenyl)Ti(N═P( t -Bu) 3 )X 2 ;

wherein R ¥ is a substituted or unsubstituted alkyl group, a substituted or an unsubstituted aryl group, or a substituted or unsubstituted benzyl group, wherein substituents for the alkyl, aryl or benzyl group are selected from alkyl, aryl, alkoxy, aryloxy, alkylaryl, arylalkyl and halide substituents; and wherein X is an activatable ligand.

3. A process for making an ethylene/1-butene copolymer, the process comprising polymerizing ethylene and 1-butene with a single site catalyst system in a gas phase polymerization reactor, wherein the ethylene/1-butene copolymer has 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.

4. The process of claim 3 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.

5. The process of claim 3 , wherein the ethylene/1-butene copolymer has an accelerated haul-off melt strength (σ MS ) as determined by Rosand capillary rheometry at 190° C., of at least 3.0 cN.

6. The process of claim 4 , wherein the ethylene/1-butene copolymer has an accelerated haul-off melt strength (σ MS ) as determined by Rosand capillary rheometry at 190° C., of at least 3.0 cN.

7. The process of claim 3 wherein the single site catalyst system comprises a phosphinimine catalyst, a cocatalyst and an inert support.

8. The process of claim 7 wherein the phosphinimine catalyst has the formula:
(1-R ¥ -Indenyl)Ti(N═P( t -Bu) 3 )X 2 ;

wherein R ¥ is a substituted or unsubstituted alkyl group, a substituted or an unsubstituted aryl group, or a substituted or unsubstituted benzyl group, wherein substituents for the alkyl, aryl or benzyl group are selected from alkyl, aryl, alkoxy, aryloxy, alkylaryl, arylalkyl and halide substituents; and wherein X is an activatable ligand.

Assignees

• Nova Chem Int Sa

Inventors

• Lam Patrick
• Ker Victoria
• Quaiattini Robert

Classifications

• C08F4/6592

  containing at least one cyclopentadienyl ring, condensed or not, e.g. an indenyl or a fluorenyl ring · CPC title

• C08F2500/19

  Shear ratio or shear ratio index · CPC title

• C08F2500/10

  Short chain branches · CPC title

• C08F210/16 Primary

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

• C08J2323/08

  Copolymers of ethene (C08J2323/16 takes precedence) · CPC title