PROCESS FOR POLYMERIZING CONJUGATED DIENE

PURPOSE:To obtain the titled crystalline polymer having a uniform particle diameter, by polymerizing a conjugated diene in the presence of a catalyst system prepared by bringing a Co compound into contact with a specific organometallic compound, etc. in the presence of a conjugated diene, and adding carbon disulfide, etc. thereto and a surfactant in the aqueous system. CONSTITUTION:A conjugated diene, e.g. butadiene, is polymerized in the presence of a catalyst system, prepared by bringing (A) a cobalt compound, e.g. cobalt octylate, previously into contact with (B) an organometallic compound of a metal selected from Groups I -III in the periodic table, e.g. triisoputylaluminum, or a hydride thereof in the presence of the conjugated diene by operating a pump (A) and a homomixer (M) in an autoclave (B), and adding (C) one or more of carbon disulfide, phenyl isothiocyanate and a xanthogen compound, etc. thereto, and one or more of a surfactant, protective colloid, metal chloride, phosphate, etc. in the polymerisation system in the aqueous system.