Coextruded multilayer film with propylene-based polymer and ethylene-based polymer

• US 10,336,041 B2
• Filed: 06/25/2014
• Issued: 07/02/2019
• Est. Priority Date: 06/28/2013
• Status: Active Grant

• Current Assignee: Dow Global Technologies LLC (Dow, Inc.)
• Original Assignee: Dow Global Technologies LLC (Dow, Inc.)
• Inventors: Jenkins, Steven R., Lee, Patrick Chang Dong, Dooley, Joseph, Kirkpatrick, Donald E., Obi, Bernard E.
• Primary Examiner(s): Shah, Samir
• Application Number:
  US14/900,462
• Publication Number:
  US 20160144605A1
• Time in Patent Office: 1,833 Days
• CPC Class Codes: B32B 2250/05 5 or more layers
• CPC Class Codes: B32B 2250/242 All polymers belonging to those covered by group B32B27/32
• CPC Class Codes: B32B 2250/40 Symmetrical or sandwich layers, e.g. ABA, ABCBA, ABCCBA
• CPC Class Codes: B32B 2250/42 Alternating layers, e.g. ABAB(C), AABBAABB(C)
• CPC Class Codes: B32B 2307/724 Permeability to gases, adsorption
• CPC Class Codes: B32B 2439/00 Containers; Receptacles closures therefor B32B2435/00
• CPC Class Codes: B32B 2439/60 Bottles
• CPC Class Codes: B32B 2439/70 Food packaging
• 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

Abstract

The present disclosure provides a coextruded multilayer films. In one embodiment, the coextruded multilayer film includes a core component having from 15 to 1000 alternating layers of layer A and layer B. Layer A has a thickness from 30 nm to 1000 nni and layer A includes a propylene-based polymer having a crystallization temperature (T_pc). Layer B includes an ethylene-based polymer having a crystallization temperature (T_Ec), wherein T_pc<T_Ec. Layer A has an effective moisture permeability less than 0.40 g-mil/100 in²/day.

Claims

1. A coextruded multilayer film comprising:

a core component comprising from 15 to 1000 alternating layers of layer A and layer B;

layer A comprising a propylene homopolymer having a density from 0.85 g/cc to 0.95 g/cc and a thickness from 30 nm to 1000 nm and a crystallization temperature (T_pc);

layer B comprising a high density polyethylene (HDPE) having a density of at least 0.94 g/cc and a crystallization temperature (T_Ec), wherein T_pc is from 115°

C. to less than 118°

C.;

T_Ec is from greater than 118°

C. to 120°

C.; and

wherein T_pc <

T_Ec; and

layer A has an effective moisture permeability less than 0.40 g-mil/100in²day.

2. The multilayer film of claim 1 wherein layer A has a thickness from 30 nm to 500 nm.

3. The multilayer film of claim 1 wherein the propylene homopolymer has a melt flow rate from 1.5 g/10 min to 2.5 g/10 min.

4. The multilayer film of claim 1 wherein the propylene homopolymer has a crystallinity from 35% to 60%.

5. The multilayer film of claim 1 wherein the core component comprises from 60 to 70 alternating layers of layer A and layer B.

6. The multilayer film of claim 1 wherein the layer A has a thickness from 100 nm to 500 nm;

and layer B comprises the high density polyethylene having a density from 0.95 g/cc to 0.97 g/cc.

7. The multilayer film of claim 1 comprising from 60 to 70 alternating layers;

the layer A has a thickness from 100 nm to 400 nm and comprises the propylene homopolymer having a melt flow rate from 1.5 g/10 min to 2.5 g/10 min;

the layer B comprises the HDPE with a density from 0.95 g/cc to 0.97 g/cc; and

the layer A has an effective moisture permeability from 0.1 to less than or equal to 0.30 g-mil/100in²/day.

8. The multilayer film of claim 1 comprising at least one skin layer.

9. The multilayer film of claim 1, wherein the layer A comprises truncated spherulites.

10. The multilayer film of claim 1 wherein layer A comprises a propylene homopolymer having:

a melt flow rate from 1.5 g/10 min to 2.5 g/10 min;

a crystallinity from 35% to 45%.

11. The multilayer film of claim 1 wherein the layer B has:

a melt index from 0.1 g/10 min to 25 g/10 min; and

a density from 0.95 g/cc to 0.97 g/cc.

12. The multilayer film of claim 1 wherein layer A has a thickness from 100 nm to 500 nm.

13. The multilayer film of claim 12 wherein the layer A comprises truncated spherulites.

14. The multilayer film of claim 1 wherein:

the

layer A comprises the propylene homopolymer having;

a melt flow rate from 1.5 g/10 min to 2.5 g/10 min;

a crystallinity from 35% to 45%; and

the layer B comprises a high density polyethylene having;

a melt index from 0.1 g/10 min to 25 g/10 min; and

a density from 0.95 g/cc to 0.97 g/cc; and

wherein the layer A has a thickness from 100 nm to 500 nm and comprises truncated spherulites.

15. The multilayer film of claim 14 wherein the number of A layers to the number of B layers is from 3:

1 to 9;

1.

16. The multilayer film of claim 1 wherein the number of A layers to the number of B layers is from 3:

1 to 9;

1.