Multimodal polyethylene

• US 10,435,493 B2
• Filed: 12/29/2015
• Issued: 10/08/2019
• Est. Priority Date: 12/30/2014
• Status: Active Grant

• Current Assignee: Abu Dhabi Polymers Co. Ltd (Borouge) LLC, Borealis AG (Government of ABU Dhabi)
• Original Assignee: Abu Dhabi Polymers Co. Ltd (Borouge) LLC
• Inventors: Buryak, Andrey, Kumar, Ashish, Ali Ahmed, Ibrahim
• Primary Examiner(s): Nutter, Nathan M
• Application Number:
  US15/540,138
• Publication Number:
  US 20170349685A1
• Time in Patent Office: 1,379 Days
• CPC Class Codes: C08F 2/001 Multistage polymerisation processes characterised by a change in reactor conditions without deactivating the intermediate polymer C08F295/00, C08F297/00 take precedence
• CPC Class Codes: C08F 210/06 Propene
• CPC Class Codes: C08F 210/08 Butenes
• CPC Class Codes: C08F 210/16 Copolymers of ethene with alpha-alkenes, e.g. EP rubbers
• CPC Class Codes: C08F 2500/04 Broad molecular weight distribution, i.e. Mw/Mn > 6
• CPC Class Codes: C08F 2500/05 Bimodal or multimodal molecular weight distribution
• CPC Class Codes: C08F 2500/07 High density, i.e. > 0.95 g/cm3
• CPC Class Codes: C08F 2500/12 Melt flow index or melt flow ratio
• CPC Class Codes: C08F 4/025 Metal oxides
• CPC Class Codes: C08F 4/6492 containing aliphatic unsaturation
• CPC Class Codes: C08F 4/6546 organo-magnesium compounds
• CPC Class Codes: C08F 4/6555 and magnesium or compounds thereof
• CPC Class Codes: C08L 2203/202 use in electrical wires or wirecoating
• CPC Class Codes: C08L 2205/025 containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure
• CPC Class Codes: C08L 23/06 Polyethene
• CPC Class Codes: C08L 23/08 Copolymers of ethene C08L23/16 takes precedence
• CPC Class Codes: C08L 23/0815 Copolymers of ethene with aliphatic 1-olefins
• CPC Class Codes: C08L 2314/02 Ziegler natta catalyst
• CPC Class Codes: H01B 11/002 Pair constructions
• CPC Class Codes: H01B 11/02 Cables with twisted pairs or quads
• CPC Class Codes: H01B 11/18 : Coaxial cables; Analogous cables having more than one inner conductor within a common outer conductor
• CPC Class Codes: H01B 3/441 : from alkenes
• CPC Class Codes: H01B 7/02 : Disposition of insulation

Abstract

A multimodal polyethylene copolymer suitable for use in cable insulation comprising:

• • (III) 45 to 55 wt % of a lower molecular weight component which is an ethylene copolymer of ethylene and at least one C3-12 alpha olefin comonomer, said LMW component having a density of 940 to 962 kg/m³ and an MFR₂ of 50 to 500 g/10 min;
  • (IV) 55 to 45 wt % of a higher molecular weight ethylene copolymer component of ethylene and at least one C3-12 alpha olefin comonomer;
  • wherein said multimodal polyethylene copolymer has a density of 940 to 950 kg/m³, an MFR₂ of 0.05 to 2.0 g/10 min and preferably at least one of crystallization half time>3.0 mins at 120.5° C., a crystallization half time>5.0 mins at 121° C. or a crystallization half time>10.0 mins at 122° C.

Claims

1. A multimodal polyethylene copolymer suitable for use in cable insulation comprising:

(I) 45 to 55 wt % of a lower molecular weight component which is an ethylene copolymer of ethylene and at least one C3-12 alpha olefin comonomer, said LMW component having a density of 940 to 962 kg/m³ and an MFR₂ of 50 to 500 g/10 min;

(II) 55 to 45 wt % of a higher molecular weight ethylene copolymer component of ethylene and at least one C3-12 alpha olefin comonomer;

wherein said multimodal polyethylene copolymer has a density of 940 to 950 kg/m³, an MFR₂ of 0.05 to 2.0 g/10 min and at least one of a crystallization half time>

3.0 mins at 120.5°

C., a crystallization half time>

5.0 mins at 121°

C. or a crystallization half time>

10.0 mins at 122°

C., when measured according to ISO 11357-7.

2. A multimodal polyethylene copolymer as claimed in claim 1 having a density of 942 to 948 kg/m³.

3. A multimodal polyethylene copolymer as claimed in claim 1 having an MFR₂ of 0.2 to 2.0 g/10 min.

4. A multimodal polyethylene copolymer as claimed in claim 1 prepared using a Ziegler Natta catalyst.

5. A multimodal polyethylene copolymer as claimed in claim 1 wherein said HMW copolymer component comprises at least one of 1-butene, 1-hexene and 1-octene.

6. A multimodal polyethylene copolymer as claimed in claim 1 having 47 to 53 wt % of a HMW component (II) and 53 to 47 wt % LMW component (I).

7. A multimodal polyethylene copolymer as claimed in claim 1 having a shear thinning index (SHI 5.0/300) in the range of 20.0 to 50.0.

8. A multimodal polyethylene copolymer as claimed in claim 1 wherein said LMW polymer is a copolymer with the comonomer 1-butene.

9. A multimodal polyethylene copolymer as claimed in claim 1 having at least two of

(i) a crystallization half time>

3.0 mins at 120.5°

C.,

(ii) a crystallization half time>

5.0 mins at 121°

C. or

(iii) a crystallization half time>

10.0 mins at 122°

C.

10. A multimodal polyethylene copolymer as claimed in any preceding claim having wherein the LMW component has an MFR₂ of 200 to 400 g/10 min.

11. A multimodal polyethylene copolymer as claimed in claim 1 wherein the LMW component has a density of 950 to 962 kg/m³.

12. A multimodal polyethylene copolymer as claimed in claim 1 wherein the copolymer has a petroleum jelly adsorption of 5.0 to 9.0 wt %.

13. A cable comprising a conductor surrounded by an insulation layer comprising a copolymer as claimed in claim 1.

14. A cable as claimed in claim 13 further comprising at least one filler.

15. A cable as claimed in claim 13 which is a data cable or telecommunications cable.

16. A multimodal polyethylene copolymer as claimed in claim 1 having a density of 943 to 947 kg/m³.

17. A multimodal polyethylene copolymer as claimed in claim 1 having an MFR₂ of 0.5 to 1.5 g/10 min.

18. A multimodal polyethylene copolymer as claimed in claim 1 having a shear thinning index (SHI 5.0/300) in the range of 25.0 to 45.0.

19. A multimodal polyethylene copolymer as claimed in claim 9 having all of

(i) a crystallization half time>

3.0 mins at 120.5°

C.,

(ii) a crystallization half time>

5.0 mins at 121°

C. or

(iii) a crystallization half time>

10.0 mins at 122°

C.

20. A multimodal polyethylene copolymer as claimed in claim 9 having a crystallization half time>

11.5 mins at 122°

C.

21. A multimodal polyethylene copolymer as claimed in claim 1 wherein the copolymer has a petroleum jelly adsorption of 5.5 to 8.5 wt %.

22. A cable as claimed in claim 13, wherein said insulation layer is adjacent said conductor.

23. A cable as claimed in claim 14 wherein said filler is petroleum jelly.