Elastic substantially linear ethylene polymers

An ethylene polymer having:

• a) a melt flow ratio, I10/I2,≧5.63,
• b) a molecular weight distribution, Mw/Mn, defined by the equation:
• Mw/Mn#(I10/I2)≦4.63, and
• c) a critical shear rate at onset of surface melt fracture at least 50 percent greater than the critical shear rate at the onset of surface melt fracture of a linear ethylene polymer having an I2, Mw/Mn and density within ten percent of the ethylene polymer, and
• d) a single melting point as determined by differential scanning calorimetry between −30 C. and 150 C.

An ethylene polymer having:

• a) a melt flow ratio, I10/I2,≧5.63,
• b) a molecular weight distribution, Mw/Mn of from about 1.5 to about 2.5,
• c) a critical shear rate at onset of surface melt fracture of at least 50 percent greater than the critical shear rate at the onset of surface melt fracture of a linear ethylene polymer having an I2, Mw/Mn and density within ten percent of the ethylene polymer, and
• d) a single melting point as determined by differential scanning calorimetry between −30 C. and 150 C.

An ethylene polymer characterized in that the ethylene polymer is a substantially linear ethylene polymer having:

• (a) from about 0.01 t about 3 long chain branches/1000 total carbons,
• (b) a melt flow ratio, I10/I2,≧5.63, and
• (c) a molecular weight distribution, Mw/Mn from about 1.5 to about 2.5, and
• d) a single melting point as determined by differential scanning calorimetry between −30 C. and 150 C.

A process of preparing a substantially linear ethylene polymer having a melt flow ratio, I10/I2,≧5.63, a molecular weight distribution, Mw/Mn, defined by the equation:

• Mw/Mn≦(I10/I2)−4.63, and a single melting point as determined by differential scanning calorimetr between −30 C. and 150 C. said process characterized by continuously contacting ethylene alone or ethylene and one or more C3-C20 alpha-olefins with a catalyst composition under polymerization conditions, wherein said catalyst composition is characterized as:
• 8
• wherein:
• M is a metal of group 3-10, or the Lanthanide series of the Periodic Table of the Elements;
• Cp* is a cyclopentadienyl or substituted cyclopentadienyl group bound in an O5 bonding mode to M;
• Z is a moiety comprising boron, or a member of group 14 of the Periodic Table of the Elements, and optionally sulfur or oxygen, said moiety having up to 20 non-hydrogen atoms, and optionally Cp* and Z together form a fused ring system;
• X independently each occurrence is an anionic ligand group or neutral Lewis base ligand group having up to 30 non-hydrogen atoms;
• n is 0, 1, 2, 3, or 4 and is 2 less than the valence of M;
• and
• Y is an anionic or nonanionic ligand group bonded to Z and M comprising nitrogen, phosphorus, oxygen or sulfur and having up to 20 non-hydrogen atoms, optionally Y and Z together form a fused ring system, and
• (b) an activating cocatalyst.