Multilayer structures with enhanced adhesive bonding force and articles comprising the same

Patent metadata

Field	Value
Publication number	US-12251909-B2
Application number	US-202018003521-A
Country	US
Kind code	B2
Filing date	Aug 27, 2020
Priority date	Aug 27, 2020
Publication date	Mar 18, 2025
Grant date	Mar 18, 2025

Abstract

Provided are multilayer structures and articles comprising same. The multilayer structure comprises: a biaxially-oriented polyethylene film comprising a skin layer with a matte surface and a core, the core comprising one or more core layers; a sealant film; and an adhesive adhering the sealant film to the matte surface of the skin layer of the biaxially-oriented polyethylene film. The multilayer structure can exhibit an enhanced adhesive bonding force in comparison to other multilayer structures.

First claim

We claim:

1. A multilayer structure comprising:
(a) a biaxially-oriented polyethylene film comprising a skin layer with a matte surface and a core, the core comprising one or more core layers;
(b) a sealant film; and
(c) an adhesive adhering the sealant film to the matte surface of the skin layer of the biaxially-oriented polyethylene film; wherein the skin layer comprises, based on the total weight of the skin layer, from 20 to 80 wt. % of an ethylene-based polymer and from 80 to 20 wt. % of a propylene-based polymer, each of the ethylene-based polymer and the propylene-based polymer having a storage modulus, with a difference between the storage modulus of the ethylene-based polymer and the propylene-based polymer of greater than 40 megaPascals (MPa) at 110° C. and greater than 18 MPa at 120° C.

2. The multilayer structure of claim 1 , wherein the skin layer comprises an ethylene/alpha-olefin copolymer and a propylene/ethylene copolymer, each of the ethylene/alpha-olefin copolymer and the propylene/ethylene copolymer having a storage modulus, with a difference between the storage modulus of the ethylene/alpha-olefin copolymer and the propylene/ethylene copolymer of from 110 to 130 megaPascals (MPa) at 110° and from 70 to 80 MPa at 120° C.; and wherein the matte surface of the skin layer has (i) a gloss of from 3% to 15% as measured by ASTM D2457 at an angle of 45°, or (ii) a haze greater than 45% as measured by ASTM D1003.

3. The multilayer structure of claim 1 , wherein the matte surface of the skin layer has a gloss of less than 50% as measured by ASTM D2457 at an angle of 45°.

4. The multilayer structure of claim 1 , wherein the core comprises at least 50 wt. % of an ethylene-based polymer based on the weight of all the core layers.

5. The multilayer structure of claim 1 , wherein the biaxially-oriented polyethylene multilayer film has a thickness, and the core comprising at least 50% of the film thickness.

6. The multilayer structure of claim 1 , wherein the biaxially-oriented polyethylene film is oriented in the machine direction at a draw ratio of from 2:1 to 6:1, and in the cross direction at a draw ratio of from 2:1 to 9:1.

7. The multilayer structure of claim 1 , wherein the matte surface of the skin layer has a haze of greater than 45% as measured by ASTM D1003.

8. The multilayer structure of claim 1 , wherein the skin layer comprises an ethylene-based polymer having a density of from 0.900 to 0.960 g/cc.

9. The multilayer structure of claim 1 , wherein the sealant film comprises a layer comprising at least 20 wt. %, based on total weight of the layer, of a polyolefin plastomer, a polyolefin elastomer, an ultra low density polyethylene, an ethylene acetate copolymer, an ethylene acrylic acid copolymer, or an ethylene acrylate copolymer.

10. The multilayer structure of claim 1 , wherein the sealant film has a heat seal initiation temperature of less than 120° C.

11. The multilayer structure of claim 1 , wherein the adhesive comprises a solventless adhesive, a waterborne adhesive, or a solventborne adhesive.

12. The multilayer structure of claim 1 , wherein the adhesive bonding force of the multilayer structure is at least 2.5 N/15 mm.

13. An article comprising a multilayer structure according to claim 1 .

Assignees

• Dow Global Technologies Llc
• Rohm & Haas

Inventors

• Wang Gang
• Zhao Lianjiang
• Xu Jingyi
• Yun Xiaobing
• Pan Jianping
• Chen Gaobing
• Zhu Jianliang

Classifications

• B32B2307/518

  bi-axially · CPC title

• B32B2037/1223

  film-shaped · CPC title

• B32B37/1207

  Heat-activated adhesive (B32B37/04 takes precedence) · CPC title

• B32B27/32

  comprising polyolefins {(comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30)} · CPC title

• B32B7/12

  using interposed adhesives or interposed materials with bonding properties · CPC title