Multilayer film and pouch with same

Patent metadata

Field	Value
Publication number	US-11059257-B2
Application number	US-201616336728-A
Country	US
Kind code	B2
Filing date	Sep 28, 2016
Priority date	Sep 28, 2016
Publication date	Jul 13, 2021
Grant date	Jul 13, 2021

Abstract

The present disclosure is directed to a retort pouch. In an embodiment, the retort pouch includes a multilayer film with at least three layers. The at least three layers include (A) a skin layer comprising a blend of a propylene-based polymer and a styrenic block copolymer, (B) a seal layer comprising blend of a propylene-based polymer and a styrenic block copolymer, and (C) a core layer located between the skin layer (A) and the seal layer (B). The core layer comprises a blend of (1) a propylene-based polymer, (2) an ethylene-based polymer, and (3) a crystalline block composite (CBC).

First claim

The invention claimed is:

1. A retort pouch comprising:
a multilayer film with at least three layers comprising
(A) a skin layer comprising a blend of a propylene-based polymer and a styrenic block copolymer;
(B) a seal layer comprising a blend of a propylene-based polymer and a styrenic block copolymer;
(C) a core layer located between the skin layer (A) and the seal layer (B), the core layer comprising a blend of
(1) a propylene-based polymer,
(2) an ethylene-based polymer, and
(3) a crystalline block composite (CBC).

2. The retort pouch of claim 1 wherein the core layer (C) is void of styrene.

3. The retort pouch of claim 1 wherein the propylene-based polymer in the seal layer is a propylene/α-olefin copolymer.

4. The retort pouch of claim 1 wherein the styrenic block copolymer in the seal layer is a styrene-ethylene-butene-styrene block copolymer.

5. The retort pouch of claim 1 wherein the crystalline block composite CBC comprises
(i) a crystalline ethylene polymer (CEP) comprising at least 90 mol % polymerized ethylene;
(ii) a crystalline alpha-olefin-based polymer (CAOP) and
(iii) a block copolymer comprising
(A) a crystalline ethylene block (CEB) block comprising at least 90 mol % polymerized ethylene and
(B) a crystalline alpha-olefin block (CAOB).

6. The retort pouch of claim 1 comprising
from 5 vol % to 15 vol % layer A;
from 5 vol % to 15 vol % layer B; and
from 70 vol % to 90 vol % layer C.

7. The retort pouch of claim 6 wherein
layer A comprises from 80 wt % to 90 wt % propylene homopolymer and from 20 wt % to 10 wt % styrenic block copolymer;
layer B comprises from 80 wt % to 90 wt % propylene/ethylene copolymer and from 20 wt % to 10 wt % styrenic block copolymer; and
layer C comprises
(1) from 65 wt % to 75 wt % propylene/α-olefin copolymer,
(2) from 20 wt % to 30 wt % ethylene-based elastomer,
(3) from 3 wt % to 7 wt % of the CBC.

8. The retort pouch of claim 7 wherein the multilayer film has a haze value (post-retort) from 4 to less than 9.

9. The retort pouch of claim 8 wherein the multilayer film has a Dart impact strength (at −10° C.) from 0.6 J to 1.5 J.

10. The retort pouch of claim 9 wherein the retort pouch is a IV bag.

11. The retort pouch of claim 1 wherein the styrenic block copolymer in the skin layer and the styrenic block copolymer in the seal layer each is a styrene-ethylene-butene-styrene block copolymer.

12. The retort pouch of claim 1 wherein the propylene-based polymer in the skin layer is a propylene homopolymer.

Assignees

• Dow Global Technologies Llc

Inventors

• Lu Hang
• Xu Joy Jingyi
• Maehara Yutaka
• Pan Jian-Ping
• Yun Xiao Bing

Classifications

• Y10T428/31938

  Polymer of monoethylenically unsaturated hydrocarbon · CPC title

• B32B27/08 Primary

  of synthetic resin · CPC title

• B32B7/04

  Interconnection of layers · CPC title

• B32B2307/558

  Impact strength, toughness · CPC title

• Y10T428/1334

  Nonself-supporting tubular film or bag [e.g., pouch, envelope, packet, etc.] · CPC title