Ethylene/1-butene copolymers with enhanced resin processability

• US 10,370,469 B2
• Filed: 09/29/2017
• Issued: 08/06/2019
• Est. Priority Date: 05/27/2015
• Status: Active Grant

• Current Assignee: Nova Chemicals
• Original Assignee: Nova Chemicals
• Inventors: Lam, Patrick, Ker, Victoria, Quaiattini, Robert
• Primary Examiner(s): Lu, Caixia
• Application Number:
  US15/720,233
• Publication Number:
  US 20180022844A1
• Time in Patent Office: 676 Days
• CPC Class Codes: B32B 2250/24 All layers being polymeric
• CPC Class Codes: B32B 2307/4026 within the layer by addition of a colorant, e.g. pigments, dyes
• CPC Class Codes: B32B 2307/54 Yield strength; Tensile strength
• CPC Class Codes: B32B 2307/558 Impact strength, toughness
• CPC Class Codes: B32B 2307/5825 Tear resistant
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/32 comprising polyolefins comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30
• CPC Class Codes: B32B 27/327 comprising polyolefins obtained by a metallocene or single-site catalyst
• CPC Class Codes: B32B 7/12 using interposed adhesives or interposed materials with bonding properties
• CPC Class Codes: C08F 210/08 Butenes
• CPC Class Codes: C08F 210/16 Copolymers of ethene with alpha-alkenes, e.g. EP rubbers
• CPC Class Codes: C08F 2410/02 Anti-static agent incorporated into the catalyst
• CPC Class Codes: C08F 2420/04 Cp or analog not bridged to a non-Cp X ancillary anionic donor
• CPC Class Codes: C08F 2500/06 Comonomer distribution, e.g. normal, reverse or narrow
• CPC Class Codes: C08F 2500/10 Short chain branches
• CPC Class Codes: C08F 2500/11 Melt tension or melt strength
• CPC Class Codes: C08F 2500/12 Melt flow index or melt flow ratio
• CPC Class Codes: C08F 2500/19 Shear ratio or shear ratio index
• CPC Class Codes: C08F 2500/26 Use as polymer for film forming
• CPC Class Codes: C08F 4/65912 in combination with an organoaluminium compound
• CPC Class Codes: C08F 4/65916 : supported on a carrier, e.g. silica, MgCl2, polymer
• CPC Class Codes: C08F 4/6592 : containing at least one cyclopentadienyl ring, condensed or not, e.g. an indenyl or a fluorenyl ring
• CPC Class Codes: C08J 2323/08 : Copolymers of ethene C08J2323/16 takes precedence
• CPC Class Codes: C08J 5/18 : Manufacture of films or sheets

Abstract

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

Claims

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/cm³, 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)X₂;

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/cm³, a melt index (I₂) of from 0.5 to 10 g/10 min, a melt flow ratio (I₂₁/I₂) 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:

(CDBI₅₀/δ

_XO)^3.0≤

6.5−

5.7 log [a(1.5(I₂₁/I₂)+(M_w/M_n))];

where CDBI₅₀ 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<sup>−

4</sup>×

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)X₂;

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.