Single site polymer
View Patent ↗A single site catalysed ethylene polymer including ethylene and optionally at least one comonomer having a Mw/Mn of less than 5 and wherein the total amount of unsaturations of the ethylene polymer is at least 0.8.
1. A single site catalysed ethylene polymer comprising ethylene and optionally at least one comonomer having a Mw/Mn of less than 5, a density of at least 930 kg/m 3 and wherein the total amount of unsaturations of the ethylene polymer (per average molecule) is at least 0.8.
2. A polymer as claimed in claim 1 having a density of 940 to 955 kg/m 3 .
3. A polymer as claimed in claim 1 having an ethylene content of at least 85 wt %.
4. A polymer as claimed in claim 1 having an MFR 21 of 5 to 50 g/10 min.
5. A polymer as claimed in claim 1 having an Mn value of 25,000 to 75,000.
6. A polymer as claimed in claim 1 having an Mw/Mn of less than 3.
7. A polymer as claimed in claim 1 having carbon-carbon double bonds/1000 carbon atoms in a total amount of at least 0.2/1000 carbon atoms.
8. A polymer as claimed in claim 1 being a homopolymer.
9. A polymer as claimed in claim 1 made using a metallocene catalyst.
10. A polymer as claimed in claim 1 made by a catalyst of formula (I)
Cp′ 2 M′X′ 2
wherein each X′ is halogen, C 1-6 alkyl, benzyl or hydrogen;
M′ is Hf or Zr;
Cp′ is a substituted or unsubstituted cyclopentadienyl or indenyl group.
11. A composition comprising an ethylene polymer as claimed in claim 1 .
12. A process for the preparation of a crosslinked ethylene polymer pipe comprising polymerizing ethylene or ethylene and at least one comonomer in the presence of a single site catalyst to form an ethylene homopolymer or copolymer having a Mw/Mn of less than 5 and wherein the total amount of unsaturations of the ethylene polymer (per average molecule) is at least 0.8 into a pipe by extrusion and crosslinking in the absence of hydrogen.
13. A cross-linked pipe comprising a cross-linked single site catalysed ethylene polymer comprising an ethylene homopolymer or copolymer having a Mw/Mn of less than 5 and wherein the total amount of unsaturations of the ethylene homopolymer or copolymer (per average molecule) is at least 0.8.
14. A pipe as claimed in claim 13 wherein said pipe has a torque max value of at least 7 dNm.
15. A polymer as claimed in claim 10 made by a catalyst of Formula (I) wherein Cp′ is substituted by one or more C 1-10 hydrocarbyl groups.
16. A polymer as claimed in claim 10 made by a catalyst of Formula (I) wherein said Cp′ substituents are bridged.
17. A polymer as claimed in claim 10 made by a catalyst of Formula (I) wherein said Cp′ substituents are bridged with an ethylene or dimethylsilyl link.
18. A process comprising polymerising ethylene or ethylene and at least one comonomer in the presence of a single site catalyst to prepare a single site catalysed ethylene polymer comprising ethylene and optionally at least one comonomer having a Mw/Mn of less than 5, a density of at least 930 kg/m 3 and wherein the total amount of unsaturations of the ethylene polymer (per average molecule) is at least 0.8.