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

A polyurethane comprising a phenolic hydroxyl group represented by the following general formula (1A),

• wherein Az represents a linear, branched, or cyclic (ka+2)-valent hydrocarbon group or a fluorinated hydrocarbon group having 1 to 20 carbon atoms, and —CH2— constituting the (ka+2)-valent hydrocarbon group is optionally substituted with —O—, —NR4—, —C(═O)—, or —Si(R2R3)—;
• each of R2 and R3 is a linear, branched, or cyclic alkyl group having 1 to 6 carbon atoms, or a phenyl group;
• R4 is a hydrogen atom, or a linear or branched alkyl group having 1 to 4 carbon atoms;
• Z represents a single bond or an oxygen atom;
• each Xf independently represents a hydrogen atom, a halogen atom, a linear, branched, or cyclic monovalent hydrocarbon group having 1 to 10 carbon atoms optionally substituted with a fluorine atom, an alkoxy group having 1 to 10 carbon atoms optionally substituted with a fluorine atom, or an electron-withdrawing group;
• each of ring ZZ independently represents an aromatic monocyclic or polycyclic ring having 5 to 20 carbon atoms;
• each carbon atom of the ring ZZ is optionally substituted with a nitrogen atom, an oxygen atom, or a sulfur atom;
• “ka” represents an integer of 0 to 2;
• “kb” and “kd” each represent 1 or 2;
• “kc” and “ke” each represent an integer of 0 to 2;
• and a dashed line represents a bonding arm.