Catalyst for norbornene monomer polymerization and method for producing norbornene polymer

1. A catalyst for the polymerization of norbornene monomers, comprising (i) transition metal complex (A) represented by formula (1)

wherein M represents one transition metal selected from the elements belonging to eight, nine or ten group of the periodic table for 1991, and R 1 , R 2 and R 3 independently represent a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms; R 4 represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms; R 5 , R 6 , R 7 , R 8 and R 9 represent independently from each other a hydrogen atom, a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms; and R 5 , R 6 , R 7 , R 8 and R 9 may bond to each other to form a ring structure, and

(ii) cocatalyst (B) which is an ionic compound which can generate a cationic transition metal compound by reacting with transition metal complex (A) and a phosphine ligand (C).

2. The catalyst for the polymerization of norbornene monomers as claimed in claim 1 , wherein M represents palladium (Pd) or nickel (Ni); R 1 , R 2 and R 3 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; R 4 represents an aryl group having 6 to 20 carbon atoms; and all of R 5 , R 6 , R 7 , R 8 and R 9 represent a hydrogen atom in formula (1).

3. The catalyst for the polymerization of norbornene monomers as claimed in claim 2 , wherein M represents palladium; R 1 and R 3 represent a methyl group; R 2 represents a hydrogen atom; and R 4 represent a 2,6-diisopropylphenyl group or a 1-naphthyl group in formula (1).

4. The catalyst for the polymerization of norbornene monomers as claimed in claim 1 , wherein cocatalyst (B) is trityl tetrakis(pentafluorophenyl)borate or N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate.

5. The catalyst for the polymerization of norbornene monomers as described in claim 1 , wherein phosphine ligand (C) is trialkylphosphine.

6. The catalyst for the polymerization of norbornene monomers as claimed in claim 5 , wherein phosphine ligand (C) is triisopropylphosphine.

7. A method for producing norbornene (co)polymers comprising homopolymerization of norbornene monomers alone or copolymerization of norbornene monomers in the presence of the catalyst as claimed in claim 1 .

8. A method for producing norbornene copolymers comprising copolymerization of norbornene monomers and other vinyl monomers in the presence of the catalyst as claimed in claim 1 .

9. A method for producing norbornene copolymers comprising monomer units represented by formulae (2) and (3),

wherein R 10 represents an alkyl group having 1 to 10 carbon atoms; and R 11 , R 12 and R 13 independently represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, comprising polymerization of norbornene monomers corresponding to the monomer unit represented by formulae (2) and (3) in the presence of the catalyst as claimed in claim 1 .

10. The method for producing norbornene copolymers as claimed in claim 9 , wherein the copolymers comprise a monomer unit represented by formulae (2) and (3) only.

11. (π-allyl){4-(2,6-diisopropylphenylimino)-2-penten-2-olato-κ 2 N,O}palladium.

12. (π-allyl){4-(1-naphthylimino)-2-penten-2-olato-κ 2 N,O}palladium.