| abstract |
A chlorinated ethylene-propylene copolymer having a chlorine content of 20 to 45% by weight and a Mooney viscosity (ML1+4, 100 DEG C.) of 10 to 150 is produced by chlorinating in two or three stages, by contact with chlorine gas in an aqueous suspension, an ethylene-propylene copolymer having a propylene content of 15 to 40% by weight, a melt flow index of 0.01 to 5.0 g/10 minutes, a melting peak as measured by differential scan calorimeter (DSC) of 80 DEG C. or more, a crystallinity as measured by X-rays of 3% or more, an index &upbar& MW/ &upbar& MN of the distribution of molecular wieght, determined by gel permeation chromatography (GPC), of greater than 4, and a Mooney visocisty (ML1+4, 100 DEG C.) of 10 to 180. A vulcanizable composition having superior physical properties may be obtained by formulating with (A) the chlorinated ethylene-propylene copolymer, (B) a thiourea compound, (C) sulfur and/or a sulfur donor, (D) a metal compound, and further, if necessary, (E) a dicarbamate or (F) a mercaptotriadizine compound. Further, a cross-linkable composition having superior physical properties may be obtained by formulating (A) the chlorinated ethylene-propylene copolymer with (G) an organic peroxide. |