Extrusion coating structure

• US 6,291,590 B1
• Filed: 09/07/1999
• Issued: 09/18/2001
• Est. Priority Date: 01/10/1997
• Status: Expired due to Term

• Current Assignee: Borealis Polymers Oy (Government of ABU Dhabi)
• Original Assignee: Borealis Technology Oy (IPIC Holdings GmbH)
• Inventors: Laiho, Erkki, Sainio, Markku, Vähälä, Martti, Salminen, Hannu
• Primary Examiner(s): Nutter, Nathan M.
• Application Number:
  US09/341,426
• Time in Patent Office: 742 Days
• Field of Search: 525/191, 525/240, 428/474.4, 428/475.8, 428/476.1, 428/480, 428/483, 428/500, 428/507, 428/511, 428/532, 428/535, 428/537.5, 428/688
• US Class Current: 525/191
• CPC Class Codes: B32B 15/085 comprising polyolefins
• CPC Class Codes: B32B 15/20 comprising aluminium or copper B32B15/016 and B32B15/017 take precedence
• CPC Class Codes: B32B 2311/24 Aluminium
• CPC Class Codes: B32B 2317/12 Paper, e.g. cardboard
• CPC Class Codes: B32B 2323/04 Polyethylene
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/10 of paper or cardboard
• CPC Class Codes: B32B 27/32 comprising polyolefins comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30
• CPC Class Codes: C08L 2205/02 containing two or more polymers of the same C08L -group
• CPC Class Codes: C08L 23/0815 Copolymers of ethene with aliphatic 1-olefins
• CPC Class Codes: C08L 2666/04 Macromolecular compounds according to groups C08L7/00 - C08L49/00, or C08L55/00 - C08L57/00; Derivatives thereof
• CPC Class Codes: Y10T 428/31725 Of polyamide
• CPC Class Codes: Y10T 428/31743 Next to addition polymer from unsaturated monomer[s]
• CPC Class Codes: Y10T 428/31746 Polymer of monoethylenically unsaturated hydrocarbon
• CPC Class Codes: Y10T 428/31786 Of polyester [e.g., alkyd, etc.]
• CPC Class Codes: Y10T 428/31797 Next to addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31855 Of addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/3188 Next to cellulosic
• CPC Class Codes: Y10T 428/31895 Paper or wood
• CPC Class Codes: Y10T 428/31971 Of carbohydrate
• CPC Class Codes: Y10T 428/31982 : Wood or paper
• CPC Class Codes: Y10T 428/31993 : Of paper

Abstract

Extrusion coating structure in which at least one layer is made of a polymer composition comprising a multimodal ethylene polymer, which contains from 80 to 100% by weight of ethylene repeating u nits and from 0 to 20% by weight of C₃-C₁₀ alpha-olefin repeating units, has a density of between 0.920 and 0.960 kg/m³, and which is a blend of at least two different ethylene polymers.

Claims

1. An extrustion structure wherein at least one layer is made of a polymer composition comprising multimodal polymer, which contains from 80 to 100% by weight of ethylene repeating units and from 0 to 20% by weight of C₃-C₁₀ alpha-olefin repeating units, has a density of between 0.920 and 0.960 g/cm³, which is a blend of at least two different ethylene polymers, with the melt flow rate MRF₂ of the blend being between 9 and 13 g/10 min, and which is applied to a substrate.

2. An extrusion coating structure according to claim 1 wherein the ethylene polymer blend is a product of a process in which a first ethylene polymer is prepared by polymerizing ethylene in the presence of a catalyst system in a first step and a second polymer is prepared by polymerizing ethylene in the presence of a catalyst system in a second step.

3. Extrusion coating structure according to claim 1 characterized in that the ethylene polymer blend is produced by mixing at least two ethylene polymers having different average molecular weights.

4. An extrusion coating structure according to claim 1 wherein said substrate of the coating structure is fiber based paper or paperboard.

5. Extrusion coating structure according to claim 4 characterized in that the grammage of paper or paperboard substrate is 20 g/m²-400 g/m².

6. An extrusion coating structure according to claim 1 wherein said substrate of the coating is a plastic film made of polyester, polyamide, polypropylene or cellophane.

7. Extrusion coating structure according to claim 6 characterized in that the thickness of the plastic film substrate is 10 μ

m-80 μ

m.

8. Extrusion coating structure according to claim 1 characterized in that the substrate of the coating is made from aluminium.

9. Extrusion coating structure according to claim 8 characterized in that the thickness of the aluminium substrate is from 6 μ

m to 300 μ

m.

10. Extrusion coating structure according to claim 1 characterized in that the ethylene polymer blend is used as the only coating layer in an extrusion coating structure.

11. Extrusion coating structure according to claim 1 characterized in that the ethylene polymer blend is used as layer in a coextruded coating structure.

12. Extrusion coating structure according to claim 11 characterized in that the layer made from the ethylene polymer blend is used as nearest to the substrate, as a mediate layer or as a surface layer.

13. An extrusion coating structure according to claim 1 wherein said ethylene polymer blend is used mixed with another polyethylene.

14. An extrustion coating structure according to any of the preceding claims wherein said another ethylene polymer is a high pressure low density ethylene polymer or copolymer.

15. Extrusion coating structure according to claim 13 characterized in that the other ethylene polymer is unimodal linear ethylene polymer.