Process for producing conjugated diene polymer

A process for producing a conjugated diene polymer, the process comprising:

• a production step of producing a conjugated diene polymer solution comprising a conjugated diene polymer and a solvent;
• and
• a devolatilization step of heating the conjugated diene polymer solution while conveying the conjugated diene polymer solution with an apparatus comprising rotary twin screws, thereby devolatilizing the solvent,
• wherein a motor current value of the screw in the devolatilization step and a motor current value of the screw under no load satisfy following relational expression (1):
• 1.05≤((I1)/(I0))≤2.00 (1)
• wherein I1 represents the motor current value [A] of the screw in the devolatilization step and I0 represents the motor current value [A] of the screw under no load,
• wherein:
• a ratio of a screw length to a screw diameter in the apparatus is 4.0 or more and 12 or less;
• and,
• in the devolatilization step, an inner volume of the apparatus and an amount of the solvent volatilizing per unit time satisfy following relational expression (2):
• 1.0≤((VA)/(V0))≤50 (2)
• wherein (V0) represents the inner volume [L] of the apparatus and (VA) represents the amount [L] of the solvent volatilizing per unit time [h].