Idemitsu Kosan, Mitsui Chemicals to Increase Propane Ratio in Petrochemical Raw Materials Dec. 5, 2016 Idemitsu Kosan Co. Ltd. (TYO:5019) and Mitsui Chemicals Inc. (TYO:4183) will increase the propane processing capacity at Chiba Chemicals Manufacturing…... Please subscribe to read the full story. Subscribe Free Trial