Liquid ethylene-alpha-olefin random copolymer, process for production thereof, and use thereof

A liquid ethylene-alpha-olefin random copolymer consisting essentially of units derived from ethylene and an alpha-olefin having 3 to 20 carbon atoms, said copolymer being characterized in that

• (a) it has an ethylene unit content in the range of 10 to 85 mole% and an alpha-olefin unit content in the range of 15 to 90 mole%,
• (b) it has a number average molecular weight (M.sub.n), measured by gel permeation chromatography, of 3.times.10.sup.2 to 1.times.10.sup.4,
• (c) it has a molecular weight distribution (M.sub.w /M.sub.n), determined by gel permeation chromatography, of not more than 2.5,
• (d) it has a B value, defined by the following equation (I), within the range defined by the following equation (II) ##EQU3## wherein P.sub.E represents the molar fraction of the ethylene component in the copolymer, P.sub.O is the molar fraction of the alpha-olefin component in the copolymer, P.sub.OE is the molar fraction of alpha-olefin/ethylene chains in the total dyad chains,
• 1. 05.ltoreq.B.ltoreq.2 (II),
• (e) signals of .alpha..beta. and .beta..gamma. based on a methylene chain between two adjacent tertiary carbon atoms in the main chain of the copolymer are not observed in the .sup.13 C-NMR spectrum of the copolymer, and
• (f) it has an iodine value in the range of 0 to 85.