Ethylene/α-olefin copolymers and lubricating oils

A method for producing ethylene/α-olefin copolymers comprising a step of copolymerizing ethylene and an α-olefin having 3 to 20 carbon atoms in the presence of an olefin polymerization catalyst including:

• a bridged metallocene compound (A) represented by the general formula [I] below, and
• at least one compound (B) selected from the group consisting of organometallic compounds (B-1), organoaluminum oxy compounds (B-2) and compounds (B-3) capable of reacting with the bridged metallocene compound (A) to form an ion pair,
• the ethylene/α-olefin copolymers satisfying the following conditions (1) to (4):
• (1) the weight average molecular weight is in the range of 1,000 to 50,000;
• (2) the molecular weight distribution (Mw/Mn, Mw:
• weight average molecular weight, Mn:
• number average molecular weight) measured by gel permeation chromatography (GPC) is not more than 2.5;
• (3) the glass transition point (Tg) measured with a differential scanning calorimeter (DSC) is below −50° C.;
• and
• (4) the value B represented by the equation [1] below is not less than 1.1;
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• B
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• P
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• (in the equation [1], PE is the molar fraction of ethylene components, PO is the molar fraction of α-olefin components, and POE is the molar fraction of ethylene⋅α-olefin sequences relative to all dyad sequences);
• in the formula [I],
• R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11 and R12 are each an atom or a substituent selected from the group consisting of a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a silicon-containing group, a nitrogen-containing group, an oxygen-containing group, a halogen atom and a halogen-containing group, and may be the same as or different from one another,
• R13 and R14 are each an atom or a substituent selected from the group consisting of a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, an aryl group, a substituted aryl group, a silicon-containing group, a nitrogen-containing group, an oxygen-containing group, a halogen atom and a halogen-containing group, and may be the same as or different from each other,
• any adjacent substituents among R1 to R14 may be bonded together to form a ring,
• Y is selected from Group XIV atoms,
• M is a titanium atom, a zirconium atom or a hafnium atom,
• Q is a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, an anionic ligand or a neutral ligand capable of coordination through a lone pair of electrons, and may be the same or different when plural,
• n is an integer of 1 to 4, and
• j is an integer of 1 to 4.