Cationic Benzoxazine (Co)Polymers

Method for producing a cationic benzoxazine (co)polymer having at least 5% of all nitrogen atoms, relative to the total number of nitrogen atoms in the cationic benzoxazine (co)polymer, present in the form of permanently quaternary nitrogen atoms, comprising the steps:

• providing at least one polymerizable benzoxazine compound;
• producing a non-cationic benzoxazine (co)polymer by polymerizing the at least one polymerizable benzoxazine compound under suitable polymerization conditions,
• wherein less than 1% of nitrogen atoms of the non-cationic benzoxazine (co)polymer, relative to the total number of nitrogen atoms in the non-cationic benzoxazine (co)polymer, are present in the form of permanently quaternary nitrogen atoms, and
• reacting the non-cationic benzoxazine (co)polymer with at least one alkylating agent in an amount wherein at least 5% of all nitrogen atoms, relative to the total number of nitrogen atoms in the non-cationic benzoxazine (co)polymer, are converted into permanently quaternary nitrogen atoms.