Abstract: In the polymerization of propylene and other higher 1-olefins, polymers which have a high degree of isotacticity and a narrow distribution of molecular weight are obtained in the presence of a catalyst system composed of a zirconium compound which is stereo-rigid and chiral and a linear or cyclic aluminoxane. In addition, the catalyst system is exceptionally active.

Abstract: The present invention relates to a process for the preparation of oligomeric alkylaluminoxanes of the general formulae: ##STR1## in which R=C.sub.1 -C.sub.6 -alkyl, preferably methyl, and n=2-40, preferably 10-20, by reacting aluminum salts containing water of crystallization, preferably aluminum sulfate containing water of crystallization, with an aluminum trialkyl, preferably aluminum trimethyl. Aluminoxanes of this type can be used as a catalyst component in the preparation of high-activity, homogeneous Ziegler catalysts.

Abstract: The invention relates to a process for the preparation of polyolefins by polymerizing olefins of the formula CH.sub.2 CHR in which R=H or C.sub.1 -C.sub.10 alkyl, on their own or as a mixture, if appropriate together with C.sub.4 -C.sub.12 .alpha.,.omega.-diolefins, in solvents, liquid monomers or the gas phase, at temperatures between -50.degree. and 200.degree. C., using a catalyst system composed of a soluble, halogen-containing transition metal compound of the general formula(cyclopentadienyl).sub.2 Me R Halin which R is cyclopentadienyl or a C.sub.1 -C.sub.6 alkyl radical or a halogen, in particular chlorine, Me is a transition metal, in particular zirconium, and Hal is a halogen, in particular chlorine, and a compound, containing aluminum, of the aluminoxane type having the general formulaeAl.sub.2 OR.sub.4 (Al(R)--O).sub.nfor a linear aluminoxane and/or(Al(R)--O).sub.n+2for a cyclic aluminoxane, in which n is a number from 4 to 20 and R is a methyl or ethyl radical, preferably a methyl radical.

Abstract: A process is disclosed for producing starch/polyolefin polymer compositions by polymerization of at least one olefin in the presence of a Ziegler-Natta catalyst. The Ziegler-Natta catalyst used is obtained by contacting dried starch with an aluminum trialkyl followed by introducing a transition metal compound of the formula(cyclopentadienyl).sub.n MR.sub.mwherein M is selected from the group consisting of Cr, Ti, V or Zr, R is a lower hydrocarbon radical or acetyl acetonate, and n and m are integers from 0 to 4 and n+m equals 2 to 4.

Abstract: A fluidized bed reactor for the pyrolysis of pieces of rubber or the like, especially old tires the reactor comprising a container at the lower part of which there is discharge device for non-volatile pyrolysis products; gas blowing nozzles arranged in a zone above the discharge device for supplying a fluidizing gas and for producing a fluidized bed from material such as sand or alumina added to the reactor; preferably a heating device, especially one comprising heating tubes extending across the container; a gas outlet disposed in the zone above the fluidized bed; and supply means for conveying pieces of material to be pyrolized to the container; this apparatus is characterized by the fact that the gas blowing nozzles are arranged to direct the gas downwardly, that at least one group of nozzles are arranged in a common horizontal plane, and that the material supply device is such that its dimensions are comparable with the cross-sectional surface of the fluidized bed.