Abstract: A thermoplastic elastomer composition comprising (A) 10-90 parts by weight of crystalline polypropylene, (B) 10-90 parts by weight of brominated butyl rubber, (C) 10-120 parts by weight of olefinic copolymer rubber to 100 parts by weight of (A)+(B), and (D) 10-150 parts by weight of process oil as plasticizer to 100 parts by weight (A)+(B), all of which are dynamically vulcanized in the presence of a peroxide crosslinking agent.The thermoplastic elastomer composition of this invention has a high gel ratio or gel content in part because brominated butyl rubber is vulcanized with peroxide. The composition has good elasticity, high mechanical strength, low compressively permanent set, excellent long-term heat stability, moldability, and gas impermeability and high damping characteristic.

Abstract: A thermoplastic elastomer composition prepared by dynamically vulcanizing a composition comprised (A) polyolefin 5-50 wt. parts, (B) brominated butyl rubber 5-50 wt. parts, (C) polychloroprene rubber 5-50 wt. parts and (D) process oil 10-50 wt. parts in the presence of peroxide is disclosed.

Abstract: A thermoplastic elastomer composition and process comprising a crystalline polyolefin, halogenated butyl rubber, olefin copolymer rubber, polyolefin modified with, e.g., maleic anhydride, and, optionally nitrile rubber, wherein the halogenated butyl rubber is at least partially crosslinked using a metal oxide and/or chloride, e.g., zinc oxide. Crosslinking is achieved under dynamic mixing conditions and the resulting composition has superior strength, performance and processing properties. Furthermore, use of nitrile rubber imparts improved oil resistance to the composition.

Abstract: A titanium trichloride catalytic complex is produced by reducing titanium tetrachloride with an organo-metal compound and then treating the resulting reduced solids product with a chlorinated saturated aliphatic hydrocarbon having three to eight carbon atoms in the presence of a complexing agent. The resulting titanium trichloride complex composition, when employed as a co-catalyst with an organo-metal compound for Ziegler-type catalysts in polymerization of .alpha.-olefins, results in uniform polymer grains with unexpectedly high polymerization activity and high stereoregular polymer yielding ratios.

Abstract: A titanium trichloride catalytic complex is produced by reducing titanium tetrachloride with an organo-metal compound and then treating the resulting reduced solids product with a chlorinated saturated aliphatic hydrocarbon having three to eight carbon atoms in the presence of a complexing agent. The resulting titanium trichloride complex composition, when employed as a co-catalyst with an organo-metal compound for Ziegler-type catalysts in polymerization of .alpha.-olefins, results in uniform polymer grains with unexpectedly high polymerization activity and high stereoregular polymer yielding ratios.