Patent ID: 7678866

Claim:
A polyethylene composition which is prepared by polymerizing ethylene and an optional olefin having at least three carbon atoms in the presence of a macromonomer, wherein the macromonomer is an ethylene polymer having a terminal vinyl group, prepared by polymerizing ethylene, or an ethylene copolymer having a terminal vinyl group, prepared by copolymerizing ethylene and an olefin having at least three carbon atoms, and the macromonomer is characterized by having: (A) a number average molecular weight (Mn) of at least 10,000, and (B) a ratio (Mw/Mn) of weight average molecular weight (Mw) to number average molecular weight (Mn), in the range of 2 to 5; (Q) a frequency of long chain branches of smaller than 0.01 per 1,000 carbon atoms, and (R) a frequency of short chain branches of smaller than 0.01 per 1,000 carbon atoms; and the polyethylene composition is characterized by comprising: (C) based on the weight of the polyethylene composition, 1% to 99% by weight of branched polyethylene which is a copolymer derived from ethylene, the macromonomer and an optional olefin having at least three carbon atoms, and 1% to 99% by weight of the macromonomer, and the polyethylene composition is further characterized by having: (D) a density in the range of 0.890 g/cm 3 to 0.980 g/cm 3 , (E) a weight average molecular weight (Mw) in the range of 30,000 to 10,000,000, (F) a ratio (Mw/Mn) of weight average molecular weight (Mw) to number average molecular weight (Mn), in the range of 2 to 30, (G) a frequency of long chain branches at least 0.01 but smaller than 0.1 per 1,000 carbon atoms, and (H) a shrinking factor (g′ value) as determined by a combination of gel permeation chromatography (GPC) and on-line intrinsic viscosity measurements, in the range of at least 0.1 but smaller than 0.9, and satisfying the following relationship (3): (M) MS 190 >22×MFR −0.88 (3) wherein MS 190 is a melt strength (MS) (mN) as measured at a temperature of 190° C., and MFR is a melt flow rate (g/10 min.) as measured under a load of 2.16 kg and at a temperature of 190° C., and further satisfying the following relationship (27): (M′) MS 160 >110−110×log(MFR) (27) wherein MS 160 is a melt strength (MS) (mN) as measured at a temperature of 160° C., and MFR is a melt flow rate (g/10 min.) as measured under a load of 2.16 kg and at a temperature of 190° C.