Multilayer films for airbag applications and related methods

Patent metadata

Field	Value
Publication number	US-12059871-B2
Application number	US-202017600398-A
Country	US
Kind code	B2
Filing date	Apr 3, 2020
Priority date	Apr 12, 2019
Publication date	Aug 13, 2024
Grant date	Aug 13, 2024

Abstract

A multilayer film is provided that includes a) a barrier layer including a thermoplastic polyester elastomer or a polyamide copolymer; b) an intermediate layer provided on the barrier layer and including a maleic anhydride (MAH)-grafted polyolefin and an α-olefin copolymer; and c) an adhesive layer provided on the intermediate layer and including a thermoplastic polyester elastomer or a polyamide copolymer. The multilayer film enables production of gas-tight multilayer laminates which exhibit an excellent peel resistance combined with a low weight and/or thickness. Further, a multilayer laminate and an inflatable airbag that include a fabric layer adhered to the multilayer film, as well as methods of manufacturing are described.

First claim

The invention claimed is:

1. A multilayer film comprising:
a) a barrier layer comprising a thermoplastic polyester elastomer or a polyamide copolymer;
b) an intermediate layer provided on the barrier layer and comprising both a maleic anhydride (MAH)-grafted polyolefin and an α-olefin copolymer; and
c) an adhesive layer provided on the intermediate layer and comprising a thermoplastic polyester elastomer or a polyamide copolymer; and
wherein in the intermediate layer, the content of maleic anhydride (MAH)-grafted polyolefin is between 10 to 95 wt.-%, and the content of α-olefin copolymer is between 5 to 90 wt.-%, based on the total weight of the intermediate layer; and
wherein a content of the MAH-grafted polyolefin is capable of exceeding the content of the α-olefin copolymer in the intermediate layer.

2. The multilayer film according to claim 1 , wherein the maleic anhydride (MAH)-grafted polyolefin is selected from MAH-grafted polyethylene, MAH-grafted polypropylene, or copolymers thereof.

3. The multilayer film according to claim 1 , wherein the maleic anhydride (MAH)-grafted polyolefin comprises 0.1 to 2.0 wt.-% MAH, based on the total weight of the maleic anhydride (MAH)-grafted polyolefin.

4. The multilayer film according to claim 1 , wherein the adhesive layer further comprises a polyolefin.

5. The multilayer film according to claim 1 , wherein in the intermediate layer, the content of α-olefin copolymer is between 10 to 65 wt.-% based on the total weight of the intermediate layer.

6. The multilayer film according to claim 1 , wherein the thickness of the barrier layer is in the range of 2 to 30 μm, the thickness of the intermediate layer is in the range of 2 to 45 μm, and the thickness of the adhesive layer is in the range of 2 to 30 μm; and/or wherein the total thickness of the multilayer film is in the range of 10 to 75 μm.

7. The multilayer film according to claim 1 , wherein the surface density of the barrier layer is in the range of from 5 to 30 g/m 2 ; the surface density of the intermediate layer is in the range of from 5 to 50 g/m 2 ; and the surface density of the adhesive layer is in the range of from 2 to 20 g/m 2 .

8. The multilayer film according to claim 1 , wherein the adhesive layer further comprises a polyethylene.

9. The multilayer film according to claim 1 , wherein in the intermediate layer, the content of maleic anhydride (MAH)-grafted polyolefin is between 35 to 90 wt.-%, and the content of α-olefin copolymer is between 10 to 65 wt.-%, based on the total weight of the intermediate layer.

10. The multilayer film according to claim 1 , wherein the surface density of the barrier layer is in the range of from 7 to 20 g/m 2 ; the surface density of the intermediate layer is in the range of from 10 to 40 g/m 2 ; and the surface density of the adhesive layer is in the range of from 3 to 10 g/m 2 .

11. The multilayer film according to claim 1 , wherein the MAH-grafted polyolefin in the intermediate layer includes a blend of MAH-grafted polyolefin and non-MAH grafted polyolefin.

12. The multilayer film according to claim 1 , wherein the α-olefin copolymer is non-MAH-grafted.

13. The multilayer film according to claim 1 , wherein the intermediate layer further comprises a polymer having a Shore D hardness according to ISO 868 of less than 80.

14. The multilayer film according to claim 13 , wherein the polymer is selected from polyolefins or thermoplastic elastomers.

15. The multilayer film according to claim 13 , wherein the polymer is selected from any of polyethylene, polypropylene, or styrene block copolymers.

16. A multilayer laminate comprising a fabric layer adhered to a multilayer film according to claim 1 via the adhesive layer.

17. The multilayer laminate according to claim 16 , wherein the fabric layer comprises a polyamide and/or a polyester.

18. An inflatable airbag comprising the multilayer laminate according to claim 16 .

19. A method of manufacturing a multilayer laminate for an airbag, comprising the steps of:
providing a multilayer film according to claim 1 , and
bonding the multilayer film to a fabric layer.

20. A method of using the multilayer film according to claim 1 for the gas-tight coating of a woven or knitted fabric.

Assignees

• Zf Automotive Germany Gmbh

Inventors

• Yamada Yosuke
• Tagami Toru
• Ludwig Michael

Classifications

• B60R2021/23552

  Knitting · CPC title

• B60R2021/23542

  Weaving · CPC title

• B60R21/235

  characterised by their material · CPC title

• B32B2605/08

  Cars · CPC title

• B32B2571/00

  Protective equipment · CPC title