Polar-group-containing olefin copolymer, polar-group-containing multinary olefin copolymer, olefin-based resin composition, and adhesive and layered product each using the same

A method of producing a polar-group-containing olefin copolymer which comprises 99.999 to 80 mol % of structural units derived from at least one of ethylene and α-olefin having 3 to 20 carbon atoms and 20 to 0.001 mol % of structural units derived from at least one polar-group-containing monomer which contains an epoxy group and is represented by the following structural formula (I) or following structural formula (II), the method comprising random copolymerization in the presence of a transition metal catalyst comprising a chelatable ligand and a Group-5 to Group-11 metal to produce a random copolymer having a linear molecular structure,

• wherein formula (I) is:
• in which R1 represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and R2, R3, and R4 each independently represents a hydrogen atom, a hydrocarbon group, or the following epoxy-group-containing specific functional group, any one of R2 to R4 being the following epoxy-group-containing specific functional group:
• Specific functional group:
• a group which essentially contains an epoxy group and has a molecular structure comprising a carbon atom, an oxygen atom, and a hydrogen atom;
• and formula (II) is:
• in which R5 to R8 each independently represents a hydrogen atom, a hydrocarbon group, or the following epoxy-group-containing specific functional group, any one of R5 to R8 being the following epoxy-group-containing specific functional group, and m is 0 to 2:
• Specific functional group:
• a group which essentially contains an epoxy group and has a molecular structure comprising a carbon atom, an oxygen atom, and a hydrogen atom,
• wherein the polar-group-containing olefin copolymer has a melting point of 50 to 140° C., the melting point being determined by a differential scanning calorimeter by heating the polymer to 200° C. at 10° C./minute, maintaining the temperature of 200° C. for 5 minutes, cooling the polymer to 30° C. at 10° C./minute, maintaining the temperature at 30° C. for 5 minutes, and then heating the polymer at 10° C./minute to obtain an endothermic curve for this heating, a maximum-peak temperature in the endothermic curve being the melting point;
• and
• wherein the amount of aluminum (Al) in the polar-group-containing olefin copolymer is 0 to 10,000 μg per g of the copolymer.