| abstract |
PURPOSE: To prepare the title rubber having excellent green strength and adhesivity and sufficient rubber-like elasticity, by copolymerizing isoprene with 1,4-butadiene in the presence of a specific polymerization initiator. n CONSTITUTION: An isoprene-butadiene copolymer rubber having Mooney viscosity of 30W150, Mw/Mn of 1.2W10, no crystal melting point measured by a differential scanning calorimeter at zero extention, and containing microstructure of butadiene segment having a trans bond content of 70W90%, vinyl bond content of 2W8%, isoprene content of 3W25wt%, and styrene content of 0W30wt%. The rubber can be prepared by copolymerizing isoprene with 1,4-butadiene in an inert solvent in the presence of a polymerization initiator composed mainly of a IIA group metal organic compound, and an organic lithium compound and/or an organic aluminum compound or an organic magnesium compound. n COPYRIGHT: (C)1980,JPO&Japio |