Patent ID: 8299194

Claim:
An ethylene-α-olefin copolymer comprising monomer units derived from ethylene and monomer units derived from an α-olefin having 3 to 20 carbon atoms, having a density (d) of 860 to 950 kg/m 3 , having a melt flow rate (MFR) of 0.1 to 100 g/10 min, having a ratio (Mw/Mn) of the weight average molecular weight (Mw) thereof to the number average molecular weight (Mn) thereof of 2 to 10, having a swell ratio (SR) of less than 1.35, and having a g* defined by the following formula (I) of 0.50 to 0.75, g *=[η]/([η] GPC ×g SCB *) (I) wherein [η] represents the intrinsic viscosity (unit: dl/g) of the ethylene-α-olefin copolymer, and is defined by the following formula (I-I), [η] GPC is defined by the following formula (I-II), and g SCB * is defined by the following formula (I-III), [η]=23.3×log(ηrel) (I-I) wherein ηrel represents the relative viscosity of the ethylene-α-olefin copolymer, [η] GPC =0.00046×Mv 0.725 (I-II) wherein Mv represents the viscosity average molecular weight of the ethylene-α-olefin copolymer, g SCB *=(1− A ) 1.725 (I-III) wherein A can be determined from the measurement of the content of short chain branches in the ethylene-α-olefin copolymer.