High 1,2-vinyl containg PB can be produced by the living anionic polymerization method. It used as an additive for various rubber products such as EPDM, SBS, and HNBR, since the 1,2-vinyl units react each other as a crosslinking reaction to create a network structure which contributes to the improvement of hardness, elasticity and oil-resistance in the rubber properties. In this study, we carried out the evaluation of the partially epoxidized 1,2-PB (1,2-epoxidized PB) as an additive for the formulation of chlorosulfonated polyethylene (CSM), poly (vinylidene fluoride-co-hexafluoropropylene) (FKM). This partially epoxidized 1,2-PB can undergo a cross-linking reaction of 1,2-vinyl units and an acid-accepting reaction of the 1,2-epoxydized units. The result indicates that the 1,2-epoxidized PB can be used, not only as a modifier for mechanical properties, but also as an acid acceptor for halogenated rubber formulations instead of lead monoxide of which use has been strictly controlled based on the regulation of REACH and RoHS.