Polyurethane, polyurethane production method, conductive paste composition, conductive wire, and method for producing conductive wire

A polyurethane comprising a weakly acidic functional group having a pKa of 5 to 11,

• wherein the polyurethane comprises a structure shown a following general formula (2a), or the weakly acidic functional group comprises a structure shown by a following formula (1b) or (1c),
• wherein R1 represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 3 carbon atoms;
• Aa represents a single bond, or a linear, branched, or cyclic divalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, and —CH2— constituting Aa is optionally substituted with —O—, —C(═O)—, —C(═O)O—, or —NR5—C(═O)—;
• R5 represents a hydrogen atom, or a linear or branched alkyl group having 1 to 4 carbon atoms;
• Ab and Ac each represent —O—, —O—C(═O)—NR5—, —NR5—, or —C(═O)O—;
• n1, n2, and n4 each represent an integer of 0 to 10;
• n3 represents an integer of 0 or 1;
• and a broken line represents a bonding arm,
• wherein R represents a hydrogen atom, a fluorine atom, or a linear, branched, or cyclic hydrocarbon group having 1 to 10 carbon atoms and optionally fluorinated;
• Rf represents a fluorine atom, or a linear, branched, or cyclic fluorinated hydrocarbon group having 1 to 10 carbon atoms;
• “n” represents an integer of 1 or 2;
• and a broken line represents a bonding arm.