Patent ID: 8088876

Claim:
A copolymer obtained by copolymerizing at least one monomer selected from acrylate or methacrylate monomers represented by Formulas (1) and (2), at least one monomer selected from amino group-containing monomers represented by Formulas (3) and (4) and at least one monomer selected from polar group-containing monomers represented by Formulas (5) and (6): wherein R 11 represents an alkyl group having 4 or more carbon atoms; R 12 represents a fluoroalkyl group having 1 to 14 carbon atoms, having 3 or more fluorine atoms; R 21 , R 22 , R 23 , R 24 , R 25 and R 26 each independently represent a hydrogen atom or a methyl group; R 33 and R 34 each independently represent a divalent organic group having 1 to 7 carbon atoms; R 43 , R 53 , R 44 , R 54 , R 46 and R 56 each independently represent a hydrogen atom or an organic group having 1 to 20 carbon atoms, where R 43 and R 53 , R 44 and R 54 , and R 46 and R 56 may each chemically combine to form a cyclic structure consisting of the nitrogen atom to which these are bonded and 4 to 20 carbon atoms, or a cyclic structure consisting of the nitrogen atom to which these are bonded, at least one selected from an oxygen atom, a nitrogen atom and a sulfur atom and 4 to 19 carbon atoms; R 35 represents a hydrogen atom or an alkyl group having 8 or less carbon atoms; and n represents an integer of 2 or 3 and m represents an integer of any of 1 to 30.