Polymer blend

• US 7,812,094 B2
• Filed: 07/12/2007
• Issued: 10/12/2010
• Est. Priority Date: 07/14/2006
• Status: Expired due to Fees

• Current Assignee: Borealis Technology Oy (IPIC Holdings GmbH)
• Original Assignee: Borealis Technology Oy (IPIC Holdings GmbH)
• Inventors: Kvamme, Lars Inge, Helland, Irene, Nilsen, Jorunn, Daviknes, Hans Georg
• Primary Examiner(s): Lipman; Bernard
• Application Number:
  US12/309,301
• Publication Number:
  US 20100047599A1
• Time in Patent Office: 1,188 Days
• Field of Search: 525/240
• US Class Current: 525/240
• CPC Class Codes: B32B 2270/00 Resin or rubber layer containing a blend of at least two different polymers
• CPC Class Codes: B32B 2323/043 HDPE, i.e. high density polyethylene
• CPC Class Codes: B32B 2323/046 LDPE, i.e. low density polyethylene
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/32 comprising polyolefins comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30
• 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 428/31938 Polymer of monoethylenically unsaturated hydrocarbon

Abstract

The invention relates to a polymer blend suitable for the production of film, said polymer blend comprising at least (1) a multimodal high density polyethylene (HDPE) composition and (2) a low density polyethylene (LDPE) polymer, a linear low density polyethylene (LLDPE) polymer or a mixture of LDPE and LLDPE polymers, said HDPE composition comprising a multimodal HDPE polymer which contains at least a lower molecular weight (LMW) polyethylene component and a higher molecular weight (HMW) polyethylene component.

Claims

1. A polymer blend suitable for the production of film, said polymer blend comprising at least (1) a multimodal high density polyethylene (HDPE) composition and (2) a low density polyethylene (LDPE) polymer, a linear low density polyethylene (LLDPE) polymer or a mixture of LDPE and LLDPE polymers, said HDPE composition comprising a multimodal HDPE polymer which contains at least a lower molecular weight (LMW) polyethylene component and a higher molecular weight (HMW) polyethylene component, wherein said HDPE polymer has a MFR₂ of 0.6 g/10 min or less, when determined according to ISO 1133 at 190°

C. at load of 2.16 kg, and a density of at least 935 kg/m³.

2. The blend as claimed in claim 1, wherein said HDPE polymer has an MFR₂ of 0.2 to 0.4 g/10 min.

3. The blend as claimed in claim 1, wherein said HDPE polymer has a density of 942 to 950 kg/m³.

4. The blend as claimed in claim 3, wherein said HDPE polymer has a density of 943 to 948 kg/m³.

5. The blend as claimed in claim 1, wherein the LMW component has a density of 950 to 980 kg/m³.

6. The blend as claimed in claim 1, wherein the LMW component is an ethylene homopolymer.

7. The blend as claimed in claim 1, wherein the MFR₂ of the LMW component is 30 to 500 g/10 min.

8. The blend as claimed in claim 1 wherein the HDPE polymer has an SHI(2.7/210) of 20 to 45.

9. The blend as claimed in claim 1, wherein said HDPE polymer has an Mw/Mn of 10 to 30.

10. The blend as claimed in claim 1, wherein said component (2) is an LDPE.

11. The blend as claimed in claim 1, wherein the blend comprises HDPE composition (1) in an amount of up to 30 wt % of the total amount of the blend, and, as the component (2), a LDPE polymer, a LLDPE polymer or a mixture of LDPE and LLDPE polymers in an amount of 70 to 99 wt % of the total amount of the blend.

12. The blend as claimed in claim 1, wherein the component (2) is a mixture of LDPE and LLDPE polymers, wherein the amount of LDPE is at least 60 wt % of the amount of said LDPE/LLDPE mixture and the amount of LLDPE is up to 40 wt % of the amount of said LDPE/LLDPE mixture.

13. The blend as defined in claim 1, wherein LLDPE polymer is a multimodal LLDPE comprising at least a lower molecular weight (LMW) component and a higher molecular weight (HMW) component, and being produced using a Ziegler Natta or single site catalyst.

14. A mono- or multilayer film structure comprising at least one layer which comprises the blend as defined in claim 1.

15. A shrink film comprising a mono- or multilayer film as defined in claim 14.

17. A process for the preparation of a film comprising extruding a polymer blend as defined in claim 1 to form a layer of mono- or multilayer film structure.

16. The A process for preparing a film, comprising extruding a multimodal HDPE composition comprising a multimodal HDPE polymer which contains at least a LMW polyethylene component and a HMW polyethylene component, wherein said HDPE polymer has a MFR₂ of 0.6 g/10 min or less, when determined according to ISO 1133 at 190°

C. at load of 2.16 kg, and a density of at least 935 kg/m , in a blend with a LDPE polymer, a LLDPE polymer or a mixture of LDPE or LLDPE polymers.