POLYETHYLENE COMPOSITION
A polyethylene composition having a good balance of strength, flexibility and processability is disclosed, comprising (a) 40-55 wt % of a copolymer fraction (A) comprising ethylene and a C 4 -C 10 alpha-olefin, and having an MI 2 of from greater than 300 to 800 g/10 min or a Mw of 15 to 35 kDa; and (b) 45-60 wt % of a copolymer fraction (B) comprising ethylene and a C 4 -C 10 alpha-olefin, wherein the composition has an unpigmented density of 940 to 956 kg/m 3 and an MI 5 of 0.1 to 1 g/10 min.
1 - 17 . (canceled)
18 . Polyethylene composition comprising
(a) 40-55 wt % of a copolymer fraction (A) comprising ethylene and a C 4 -C 10 alpha-olefin, and having an MI 2 of from greater than 300 to 800 g/10 min; and
(b) 45-60 wt % of a copolymer fraction (B) comprising ethylene and a C 4 -C 10 alpha-olefin, wherein the composition has an unpigmented density of 940 to 956 kg/m 3 and an MI 5 of 0.1 to 1 g/10 min.
19 . Composition according to claim 18 , wherein copolymer fraction (A) has a weight average molecular weight Mw of from 15 to 35 kDa.
20 . Composition according claim 18 , which has a substantially uniform or reverse comonomer distribution in one or both of fractions (A) and (B).
21 . Polyethylene composition comprising
(a) 40-55 wt % of a copolymer fraction (A) comprising ethylene and a C 4 -C 10 alpha-olefin,
(b) 45-60 wt % of a copolymer fraction (B) comprising ethylene and a C 4 -C 10 alpha-olefin, wherein the composition has an unpigmented density of 940 to 956 kg/m 3 and an MI 5 of 0.1 to 1 g/10 min,
wherein the composition has a substantially uniform or reverse comonomer distribution in one or both of fractions (A) and (B),
22 . Composition according to claim 21 , wherein copolymer fraction (A) has an MI 2 of from greater than 300 to 800 g/10 min, and/or copolymer fraction (A) has a weight average molecular weight Mw of from 15 to 35 kDa.
23 . Polyethylene composition comprising
(a) 40-55 wt % of a copolymer fraction (A) comprising ethylene and a C 4 -C 10 alpha-olefin, and having a weight average molecular weight Mw of from 15 to 35 kDa; and
(b) 45-60 wt % of a copolymer fraction (B) comprising ethylene and a C 4 -C 10 alpha-olefin, wherein the composition has an unpigmented density of 940 to 956 kg/m 3 and an MI 5 of 0.1 to 1 g/10 min.
24 . Composition according to claim 23 , wherein copolymer fraction (A) has an MI 2 of from greater than 300 to 800 g/10 min.
25 . Composition according claim 23 , which has a substantially uniform or reverse comonomer distribution in one or both of fractions (A) and (B).
26 . Composition according to claim 18 , which comprises 45-55 wt % of ethylene copolymer fraction (A) and 45-55 wt % of ethylene copolymer fraction (B).
27 . Composition according to claim 18 , which has an unpigmented density of 942 to 954 kg/m 3 .
28 . Composition according to claim 18 , which has an η 210kPa of less than 6 kPa·s.
29 . Composition according to claim 18 , wherein both copolymer (A) and copolymer (B) both independently contain between 0.3 and 1 mol % of alpha-olefin.
30 . Composition according to claim 18 , wherein the comonomer in both copolymer (A) and copolymer (B) is independently 1-butene, 1-hexene or 1-octene.
31 . Composition according to claim 18 , which comprises 45-55 wt % of ethylene copolymer fraction (A) and 45-55 wt % of ethylene copolymer fraction (B), wherein copolymer (A) and copolymer (B) both contain the same comonomer.
32 . Composition according to claim 18 , wherein copolymer (A) has an MI 2 of at least 320 g/10 min, preferably 320-500 g/10 min.
33 . Composition according to claim 18 , which has an MI 5 of 0.2 to 0.7 g/10 min.
34 . Composition according to claim 18 , which additionally contains up to 10 wt %, preferably up to 5 wt % of a prepolymer.