Compound having bisazo skeleton, pigment dispersant containing the compound, pigment composition, pigment dispersion, ink and resist composition for color filter

A compound containing a polymer unit to which a unit represented by formula (1) or (2) is bound, wherein said polymer unit has at least one of partial structures represented by formulae (3) and (4):

• wherein
• R1 to R4 represent a hydrogen atom or a halogen atom,
• R5 and R6 represent an alkyl group having 1 to 6 carbon atoms or a phenyl group,
• R7 to R11 represent a hydrogen atom, a COOR12 group, or a CONR13R14 group, at least one of R7 to R11 is a COOR12 group or a CONR13R14 group, and R12 to R14 represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and
• L1 represents a divalent linking group;
• wherein R15 represents a hydrogen atom or an alkyl group;
• wherein R16 represents a hydrogen atom or an alkyl group, and R17 represents a hydrogen atom, an alkyl group, or an aralkyl group.