Tubular Low Density Ethylene-Based Polymers with Improved Balance of Extractables and Melt Elasticity

• US 20160304638A1
• Filed: 11/20/2014
• Published: 10/20/2016
• Est. Priority Date: 12/19/2013
• Status: Active Grant

• Current Assignee: Dow Global Technologies LLC (Dow, Inc.)
• Original Assignee: Dow Global Technologies LLC (Dow, Inc.)
• Inventors: Den Doelder, Cornelis F.J., Berbee, Otto J., Hinrichs, Stefan, Karjala, Teresa P.
• Granted Patent: US 9,765,160 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: C08F 10/02 Ethene
• CPC Class Codes: C08F 110/02 Ethene
• CPC Class Codes: C08F 2/00 Processes of polymerisation
• CPC Class Codes: C08F 2/001 Multistage polymerisation processes characterised by a change in reactor conditions without deactivating the intermediate polymer C08F295/00, C08F297/00 take precedence
• CPC Class Codes: C08F 2/01 characterised by special features of the polymerisation apparatus used
• CPC Class Codes: C08F 2/38 Polymerisation using regulators, e.g. chain terminating agents , e.g. telomerisation
• CPC Class Codes: C08F 2500/04 Broad molecular weight distribution, i.e. Mw/Mn > 6
• CPC Class Codes: C08F 2500/05 Bimodal or multimodal molecular weight distribution
• CPC Class Codes: C08F 2500/12 Melt flow index or melt flow ratio
• CPC Class Codes: C08F 4/38 Mixtures of peroxy-compounds

Abstract

The invention provides an ethylene-based polymer comprising the following properties: a) weight fraction (w) of molecular weight above 5*10⁶ g/mol, w>A−B*I2, where A=0.4 wt %, and B is 0.02 wt %/(dg/min), and w<C−B*I₂%, where C=0.9 wt %; and b) G′>D−E*log(I2), where D=162 Pa and E=52 Pa/log(dg/min).

Claims

1. An ethylene-based polymer comprising the following properties:

a) weight fraction (w) of molecular weight above 5*10⁶ g/mol, w>

A−

B*I2, where A=0.4 wt %, and B is 0.02 wt %/(dg/min), and w<

C−

B*I₂%, where C=0.9 wt %; and

b) G′

>

D−

E*log(I2), where D=162 Pa and E=52 Pa/log(dg/min).

2. The ethylene-based polymer of claim 1, wherein the polymer has a melt index (I₂) from 0.3 to 16 dg/min.

3. The polymer of claim 1 or 2, in which the n-hexane extractables are <

X wt %+Y*log(I₂), where X=2.3 wt % and Y=1.66 wt %/log(dg/min).

4. The polymer of claim 1 or 2, in which the n-hexane extractables are <

X wt %+Y*log(I₂), where X=2.3 wt % and Y=1.66 wt %/log(dg/min) when the I₂ is as follows;

0.5 dg/min<

I2<

12 dg/min.

5. The polymer of any one of the preceding claims, in which the ethylene-based polymer has a weight fraction (w) of molecular weight above 5*10⁶ g/mol, greater than 0.4 wt % and smaller than 0.7 wt %.

6. The polymer of any one of the preceding claims, in which the ethylene-based polymer has a Mw(abs)/Mn(abs) from 15.0 to 25.0.

7. The polymer of any one of the preceding claims, in which the ethylene-based polymer has a density from 0.916 to 0.925 g/cc.

8. The polymer of any one of the preceding claims, in which the ethylene-based polymer has a melt index (I₂) from 0.8 to 10 dg/min.

9. The polymer of any one of the preceding claims, in which the ethylene-based polymer is a polyethylene homopolymer.

10. The polymer of claim 9 in which the ethylene-based polymer is LDPE.

11. The polymer of any one of the preceding claims, in which the ethylene-based polymer is prepared in a reactor configuration comprising at least one tubular reactor.

12. The polymer of claim 11 in which the tubular reactor comprises at least three reaction zones.

13. A composition comprising the ethylene-based polymer of any one of the preceding claims.

14. An article comprising at least one component formed from the composition of claim 13.