Multilayered polyolefin-based films

Patent metadata

Field	Value
Publication number	US-9511567-B2
Application number	US-201314425400-A
Country	US
Kind code	B2
Filing date	Sep 13, 2013
Priority date	Sep 14, 2012
Publication date	Dec 6, 2016
Grant date	Dec 6, 2016

Abstract

Disclosed are multilayer structures comprising a polyolefin layer, a tie layer and a barrier layer wherein the tie layer is a formulation comprising a crystalline block copolymer composite (CBC) comprising i) an ethylene polymer (EP) comprising at least 90 mol % polymerized ethylene; ii) an alpha-olefin-based crystalline polymer (CAOP) and iii) a block copolymer comprising (a) an ethylene polymer block comprising at least 90 mol % polymerized ethylene and (b) a crystalline alpha-olefin block (CAOB).

First claim

What is claimed is:

1. A multilayer structure comprising a polypropylene layer which is Layer A, a tie layer which is Layer B, and a barrier layer which is Layer C, each layer having opposing facial surfaces in adhering contact with the other layer, wherein:
Layer A has a top facial surface and a bottom facial surface and comprises polypropylene;
Layer B has a top facial surface and a bottom facial surface and comprises:
a) a crystalline block copolymer composite (CBC) comprising:
i) an ethylene polymer (EP) comprising at least 90 mol % polymerized ethylene;
ii) an alpha-olefin-based crystalline polymer (CAOP) and
iii) a block copolymer comprising (a) an ethylene polymer block comprising at least 90 mol % polymerized ethylene and (b) a crystalline alpha-olefin block (CAOB);

b) a polyolefin elastomer or plastomer;
c) maleic anhydride grafted polyethylene (MAH-g-PE) or maleic anhydride grafted polypropylene (MAH-g-PP); and, optionally,
d) polypropylene or polyethylene; and,

Layer C comprises a polyamide (PA) or ethylene vinyl alcohol (EVOH) and has a top facial surface and a bottom facial surface,
wherein the top facial surface of Layer C is in adhering contact with the bottom facial surface of Layer B, and the top facial surface of Layer B is in adhering contact with the bottom facial surface of Layer A,
wherein the crystalline block copolymer composite of Layer B is present in an amount of at least 40 weight percent based on total polymer weight in Layer B, and
wherein Layer B provides an interlayer adhesion value between Layer A and Layer C of greater than 7 N/15 mm before and after the multilayer structure is subjected to a retort process.

2. The multilayer structure of claim 1 wherein Layer B further comprises a polypropylene.

3. The multilayer structure of claim 1 wherein Layer B further comprises a polyethylene.

4. The multilayer structure of claim 1 wherein the structure has a thickness of 25 microns to 2.5 cm.

5. The multilayer structure of claim 1 wherein the structure is a cast film or a blown film.

6. The multilayer structure of claim 5 wherein the multilayer structure has a film thickness of at least 3 mil.

7. A multilayer structure comprising a polypropylene layer which is Layer A, a tie layer which is Layer B, and a barrier layer which is Layer C, each layer having opposing facial surfaces in adhering contact with the other layer, wherein:
Layer A has a top facial surface and a bottom facial surface and comprises polypropylene;
Layer B has a top facial surface and a bottom facial surface and comprises:
a) a crystalline block copolymer composite (CBC) comprising:
i) an ethylene polymer (EP) comprising at least 90 mol % polymerized
ethylene;
ii) an alpha-olefin-based crystalline polymer (CAOP) and
iii) a block copolymer comprising (a) an ethylene polymer block comprising at least 90 mol % polymerized ethylene and (b) a crystalline alpha-olefin block (CAOB);

b) a polyolefin elastomer;
c) maleic anhydride grafted polyethylene (MAH-g-PE) or maleic anhydride grafted polypropylene (MAH-g-PP); and, optionally,
d) polypropylene or polyethylene; and,

Layer C comprises a polyamide (PA) or ethylene vinyl alcohol (EVOH) and has a top facial surface and a bottom facial surface,
wherein the top facial surface of Layer C is in adhering contact with the bottom facial surface of Layer B, and the top facial surface of Layer B is in adhering contact with the bottom facial surface of Layer A,
wherein the crystalline block copolymer composite of Layer B is present in an amount of at least 40 weight percent based on total polymer weight in Layer B,
wherein Layer B provides an interlayer adhesion value between Layer A and Layer C of greater than 5 N/15 mm after the multilayer structure is subjected to a retort process, and
wherein the multilayer structure is a thermoformed film.

Assignees

• Dow Global Technologies Llc

Inventors

• Hu Yushan
• Conley Burcak
• Walton Kim L
• Li Pi Shan Colin
• Marchand Gary R
• Patel Rajen M
• Kupsch Eva-Maria
• Walther Brian W

Classifications

• B32B27/08 Primary

  of synthetic resin · CPC title

• B32B2307/7244

  Oxygen barrier · CPC title

• Y10T428/31757

  Polymer of monoethylenically unsaturated hydrocarbon · CPC title

• B32B27/308

  comprising acrylic (co)polymers · CPC title

• B32B2250/40

  Symmetrical or sandwich layers, e.g. ABA, ABCBA, ABCCBA · CPC title