Method for producing copolymer of allyl monomer having polar group

A method for producing a copolymer of ethylene and an allyl monomer having a polar group represented by formula (1)

• CH2═CH—CH2—R1 (1),
• wherein R1 represents a substituent selected from the group consisting of a hydroxy group, an alkoxy group having 1 to 10 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, an acyl group having 2 to 10 carbon atoms, an ester group having 2 to 10 carbon atoms, an acyloxy group having 2 to 10 carbon atoms, an amino group, a substituted amino group having 1 to 12 carbon atoms, a substituted amido group having 2 to 12 carbon atoms, a substituted pyridyl group having 5 to 10 carbon atoms, a substituted pyrrolidyl group having 4 to 10 carbon atoms, a substituted piperidyl group having 5 to 10 carbon atoms, a substituted hydrofuryl group having 4 to 10 carbon atoms, a substituted imidazolyl group having 4 to 10 carbon atoms, a mercapto group, an alkylthio group having 1 to 10 carbon atoms, an arylthio group having 6 to 10 carbon atoms, an epoxy group, and a halogen atom, or a copolymer of ethylene, the allyl monomer having a polar group represented by formula (1) and another monomer, the method comprising polymerizing ethylene and the allyl monomer having a polar group represented by formula (1), or ethylene, the allyl monomer having a polar group represented by formula (1), and another monomer, in the presence of a metal complex, wherein the metal complex is represented by formula (C1)
• wherein M represents an element of Group 10 of the Periodic Table, X represents a phosphorus atom (P) or an arsenic atom (As), and Y represents a divalent group selected from a substituted or unsubstituted arylene group having 6 to 30 carbon atoms, a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkylene group having 3 to 30 carbon atoms, a substituted or unsubstituted imino group (—NH—), an oxy group (—O—), and a substituted or unsubstituted silylene group (—SiH2—), Q represents an anionic ligand selected from —S(═O)2—O—, —C(═O)—O—, —P(═O)(—OH)—O—, —O—, and —S—, or a neutral ligand selected from —P(—R8)(—R9)═O, and —C(—R10)═O, wherein R8, R9 and R10 each independently represent a hydrogen atom, an alkoxy group, an aryloxy group, an amino group, or a hydrocarbon group having 1 to 30 carbon atoms which may be substituted with one or more groups selected from a halogen atom, an alkoxy group, an aryloxy group, and an amino group, wherein the bonding mode is Y—S(═O)2—O-M, Y—C(═O)—O-M, Y—P(═O)(—OH)—O-M, Y—O-M, Y—S-M, Y—P(—R8)(—R9)═O-M, or Y—C(—R10)═O-M, R5 represents a substituent selected from the group consisting of a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 30 carbon atoms, a hydrocarbon group having 1 to 30 carbon atoms substituted with a halogen atom, a hydrocarbon group having 2 to 30 carbon atoms substituted with an alkoxy group having 1 to 10 carbon atoms, a hydrocarbon group having 7 to 30 carbon atoms substituted with an aryloxy group having 6 to 20 carbon atoms, a hydrocarbon group having 3 to 30 carbon atoms substituted with an amido group having 2 to 10 carbon atoms, an alkoxy group having 1 to 30 carbon atoms, an aryloxy group having 6 to 30 carbon atoms, and an acyloxy group having 2 to 10 carbon atoms, R6 and R7 each independently represent an alkoxy group, an aryloxy group, a silyl group, an amino group, or a hydrocarbon group having 1 to 120 carbon atoms which may be substituted with one or more groups selected from a halogen atom, an alkoxy group, and an aryloxy group, and may be bonded to each other to form a ring structure, L represents an electron-donating ligand and R5 and L may form a ring, q is 0, ½, 1 or 2, n represents the number of charges of the metal complex represented by formula (C1) and is 0 or 1, Zn− represents a counteranion, and is absent when n is 0, as a catalyst, and by allowing a boron compound having one or more boron-hydrogen bonds (B—H) or boron-carbon bonds (B—C) to coexist during polymerization.