Crosslinked laminated wrap film and dispenser box therefor

• US 6,682,808 B2
• Filed: 04/19/2002
• Issued: 01/27/2004
• Est. Priority Date: 04/20/2001
• Status: Expired due to Term

• Current Assignee: Asahi Kasei Chemicals Corporation (Asahi Kasei Corporation)
• Original Assignee: Asahi Kasei Kabushiki Kaisha (Asahi Kasei Corporation)
• Inventors: Kobayashi, Hisaaki, Yoshimoto, Masahide, Nakao, Takashi
• Primary Examiner(s): NAKARANI, DHIRAJLAL S
• Application Number:
  US10/125,401
• Publication Number:
  US 20030138584A1
• Time in Patent Office: 648 Days
• Field of Search: 225/48, 225/49, 225/50, 428/213, 428/219, 428/220, 428/516, 428/515, 428/523
• US Class Current: 428/213
• CPC Class Codes: B32B 27/32 comprising polyolefins comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30
• CPC Class Codes: B32B 27/322 comprising halogenated polyolefins, e.g. PTFE
• CPC Class Codes: B65D 83/0841 and for cutting interconnected articles cutting devices for dispensers intended for re-use B65H35/008
• CPC Class Codes: B65H 2701/1752 Polymer film
• CPC Class Codes: B65H 35/0006 Article or web delivery apparatus incorporating cutting or line-perforating devices
• CPC Class Codes: C08L 23/06 Polyethene
• CPC Class Codes: C08L 23/0815 Copolymers of ethene with aliphatic 1-olefins
• CPC Class Codes: C08L 2666/06 Homopolymers or copolymers of unsaturated hydrocarbons; Derivatives thereof
• CPC Class Codes: Y10T 225/248 Single blank container
• CPC Class Codes: Y10T 225/249 Blade unitary with container
• CPC Class Codes: Y10T 225/251 With closure fastener
• CPC Class Codes: Y10T 428/14 Layer or component removable to expose adhesive
• CPC Class Codes: Y10T 428/2495 Thickness [relative or absolute]
• CPC Class Codes: Y10T 428/31909 Next to second addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31913 Monoolefin polymer
• CPC Class Codes: Y10T 428/31938 Polymer of monoethylenically unsaturated hydrocarbon

Abstract

The present invention relates to wrap films, especially wrap films for food. More specifically, the present invention pertains to crosslinked laminated polyethylene wrap films which are excellent in adhesion, pulling-out ease from a dispenser box and heat resistance, does not emit much odor, permits preferable food wrapping and can be produced efficiently.

Claims

1. A crosslinked laminated wrap film having, at least, two surface layers and one intermediate layer,

wherein the two surface layers each comprises 20 to 90% by weight of a linear low density polyethylene and 80 to 10% by weight of a high pressure process low density polyethylene,

wherein the intermediate layer has at least one layer comprising 50 to 95% by weight of a high density polyethylene and 50 to 5% by weight of a high pressure process low density polyethylene, and

wherein the surface layers and intermediate layer each has 0.050 to 0.800 part by weight of glycerin monofatty acid ester based on 100 parts by weight in total of the two polyethylenes constituting the respective layer.

2. The crosslinked laminated wrap film of claim 1, wherein the surface layers each comprises 30 to 80% by weight of the linear low density polyethylene and 70 to 20% by weight of the high pressure process low density polyethylene.

3. The crosslinked laminated wrap film of claim 1, wherein the surface layers each comprises 30 to 70% by weight of the linear low density polyethylene and 70 to 30% by weight of the high pressure process low density polyethylene.

4. The crosslinked laminated wrap film of claim 1, wherein the linear low density polyethylene has a density of 0.900 to 0.929 g/cm³.

5. The crosslinked laminated wrap film of claim 1, wherein the high pressure process low density polyethylene has a density of 0.910 to 0.939 g/cm³.

6. The crosslinked laminated wrap film of claim 1, wherein the high density polyethylene has a density of 0.940 to 0.975 g/cm³.

7. The crosslinked laminated wrap film of claim 1, wherein the high density polyethylene has a melt index of 0.1 to 10.0 g/10 min.

8. The crosslinked laminated wrap film of claim 1, wherein the high density polyethylene has a melt index of 0.1 to 3.9 g/10 min.

9. The crosslinked laminated wrap film of claim 1, which has a gel fraction of 20 to 70% by weight.

10. The crosslinked laminated wrap film of claim 4, which has been subjected to biaxial stretching.

11. The crosslinked laminated wrap film of claim 1, wherein relative to the overall film thickness of the crosslinked laminated wrap film, a thickness ratio of the total of the surface layers is 70 to 10% and that of the intermediate layer is 30 to 90%.

12. The crosslinked laminated wrap film of claim 10, which has the overall film thickness of 5 to 25 μ

m.

13. The crosslinked laminated wrap film of claim 12, wherein the glycerin monofatty acid ester content of each of said layers is 0.050 to 0.500 part by weight based on 100 parts by weight of the resin amount of the respective layer.

14. The crosslinked laminated wrap film of claim 1, wherein the glycerin monofatty acid ester content of each of said layer is 0.100 to 0.300 part by weight based on 100 parts by weight of the resin amount of the respective layer.

15. The crosslinked laminated wrap film of claim 1, wherein the fatty acid ester moiety of the glycerin monofatty acid ester has 6 to 20 carbon atoms.

16. The crosslinked laminated wrap film of claim 1, wherein the fatty acid ester moiety of the glycerin monofatty acid ester is at least one ester selected from stearic acid esters and oleic acid esters.

17. The crosslinked laminated wrap film of claim 13, wherein the fatty acid ester moiety of the glycerin monofatty acid ester is an oleic acid ester.

18. The crosslinked laminated wrap film of claim 1, wherein a difference in the glycerin monofatty acid ester content based on 100 parts by weight of the resin amount of the respective layer among the two surface layers and intermediate layer is 0 to 0.300 part by weight.

19. The crosslinked laminated wrap film of any one of claims 1 to 18, which has an adhesion work volume of 0.50 to 3.50 mJ and a pulling-out power of 50 to 1000 mN.

20. A dispenser box equipped with a cutter extending its longitudinal direction and having a crosslinked laminated wrap film of claim 1 placed therein, wherein the cutter is set such that a central portion thereof in the longitudinal direction is linear and the cutter gradually inclines to a direction of a bottom line of the box sequentially toward both ends of the cutter, and the both endmost portions protrude toward the bottom line direction of the box by 2 to 15 mm relative to the central portion.