Abstract: The invention concerns a process for the production of copolymers of propylene and but-1-ene which can be used for the production of hollow bodies or heat-sealable films and wherein the proportion by weight of units derived from but-1-ene is from 10 to 40% and wherein the proportion of isolated ethyl branches is at least equal to the square of the proportion of units derived from propylene contained in said polymers. The process is characterized in that a gaseous mixture of propylene and but-1-ene is brought into contact, in the absence of liquid diluent, with a catalytic system which is stereospecific in the polymerization of propylene alone.

Abstract: A process for producing titanium-trichloride based catalyst comprising reducing titanium tetrachloride in excess with an organo-aluminum compound in the presence of 2 to 5 mols per mol of organo-aluminum of one or more aliphatic ethers having the formula R'--O--R" in which R' and R" are alkyl groups containing 1 to 5 carbon atoms and maturing the formed precipitate at a temperature within the range of 80.degree.-115.degree. C., said catalyst being useful with an organo-metallic co-catalyst in the polymerization of olefins.

Abstract: A catalyst for use in the polymerization of olefins and a process for its manufacture wherein an excess titanium tetrachloride is reduced by an organoaluminum reducing agent, with the ratio of moles of titanium tetrachloride to the number of gram equivalents of the organoaluminum compound being at least 1.8. The catalyst is prepared in the presence of an aliphatic ether to produce titanium trichloride having regularly-shaped granules and improved catalytic properties suitable for use with an organoaluminum co-catalyst in the polymerization of olefins.