Method for producing modified polymer and hydrogenated product thereof

A method for producing a modified polymer or a hydrogenated product thereof, the method comprising:

• polymerizing a monomer comprising at least one of a conjugated diene or an aromatic vinyl compound in a polymerization solvent which includes a hydrocarbon-based solvent, using a polymerization initiator which includes an active organometal to obtain a reaction solution in which the modified polymer or the hydrogenated product thereof is dissolved in the polymerization solvent;
• introducing a functional group into at least one of a main chain or a side chain of the modified polymer or the hydrogenated product thereof, using a compound having the functional group protected with a silyl group as a polymerization initiator, as a functional group-introducing monomer, or as a polymerization terminator;
• separating the reaction solution into a solvent fraction including the hydrocarbon-based solvent, and a solid fraction including the modified polymer or the hydrogenated product thereof;
• distilling the solvent fraction separated from the reaction solution to obtain a low-boiling fraction including the hydrocarbon-based solvent and a silanol compound;
• removing at least part of the silanol compound from the low-boiling fraction by liquid-liquid extraction using the low-boiling fraction and an extraction solvent;
• and
• recycling at least part of a raffinate of the low-boiling fraction from which the at least part of the silanol compound has been removed by the liquid-liquid extraction, as a polymerization solvent.