Abstract: Catalyst systems of the Ziegler-Natta type contain, as active componentsa) a titanium-containing solid component in whose preparation a titanium compound, a compound of magnesium, a halogenating agent and an electron donor component are used,b) an aluminum compound andc) as a further electron donor component, an organosilicon compound of the formula (I)R.sup.1 R.sup.2 Si(OR.sup.3).sub.2 (I)where R.sup.1 is C.sup.1 -C.sub.10 -alkyl or C.sub.3 -C.sub.8 -cycloalkyl, excluding sec-butyl, R.sup.2 is sec-butyl and R.sup.3 is C.sub.1 -C.sub.8 -alkyl. The catalyst systems are particularly suitable for the preparation of polymers of C.sub.2 -C.sub.10 -alk-1-enes.

Abstract: Copolymers of propylene with other 1-alkenes, obtainable by gas-phase polymerization of a mixture of propylene and another 1-alkene in the absence of a liquid reaction medium under a pressure of from 15 to 30 bar, at from 60.degree. to 90.degree. C. and with an average holdup time of the polymer of from 1 to 5 hours, with the aid of a Ziegler-Natta catalyst system which, besides a titanium-containing solid component, contains an aluminum component and an electron donor, with the temperature being chosen so that, under the preset pressure, no condensation of the monomer mixture takes place in the gas space and, moreover, the ratio of the partial pressures of propylene and the other 1-alkene is adjusted to from 5:1 to 100:1, are particularly suitable for producing sheets and shaped articles.

Abstract: Propylene polymers have a molecular weight ratio Q (M.sub.w /M.sub.n) of from 6 to 30 and are obtainable by Ziegler-Natta polymerization in the presence of hydrogen as molecular weight regulator and are particularly suitable for the production of films and moldings.

Abstract: Ziegler-Natta-type catalyst systems containing, as active constituents,a) a titanium-containing solid component which also contains magnesium, halogen and a carboxylic acid ester, and, as cocatalyst,b) an aluminum compound,wherein the carboxylic acid ester in the solid component is a diester of a carboxylic acid of the formula Ia or Ib ##STR1## where R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are identical or different and are hydrogen, C.sub.1 - to C.sub.15 -alkyl, C.sub.7 - to C.sub.15 -alkylaryl, or 5- to 7-membered cycloalkyl, which may itself carry C.sub.1 - to C.sub.10 -alkyl groups, are particularly suitable for the preparation of polypropylene and copolymers of propylene containing minor amounts of other .alpha.,.beta.-unsaturated olefinic compounds having from 2 to 12 carbon atoms.

Abstract: Polymers of propene are prepared using a Ziegler-Natta catalyst system consisting of (1) a titanium component which is based on a finely divided, shape-imparting silica gel and contains, in addition to titanium, magnesium, chlorine and a benzenecarboxylic acid derivative, (2) an aluminum component and (3) a silane component. In this process, a titanium component (1) is used which is obtained by a method in which (1.1) first (I) a carrier is prepared from (Ia) a silica gel, (Ib) an alkanol, (Ic) an organomagnesium compound and (Id) a gaseous chlorinating agent by a procedure in which (1.1.1) first (Ia) is reacted with (Ib), (1.1.2) then the mixture obtained in (1.1.1) is combined with (Ic), (1.1.3) then (Id) is passed into the mixture obtained in (1.1.2) and (I) is isolated, (1.2) thereafter a solid-phase intermediate is prepared from (I), (II) an alkanol, (III) titanium tetrachloride and (IV) a phthalic acid drivative by a procedure in which (1.2.1) first (I) is reacted with (II), (1.2.

Abstract: Propylene-ethylene copolymers are prepared in an agitated bed of solids by first polymerizing propylene from the gas phase in a first polymerization zone at 20-40 bar and 60.degree.-90.degree. C. by addition of a Ziegler-Natta catalyst system, and copolymerizing in a second polymerization zone at 7-35 bar and 40.degree.-70.degree. C. the finely divided polymer from the first polymerization zone with a mixture of olefins a process which comprises copolymerizing in the second polymerization zone with a mixture of propylene, ethylene and a further .alpha.-olefin of from 4 to 10 carbon atoms, setting the ratio of the partial pressures between propylene and ethylene within the range from 100:20 to 100:120 and that of the partial pressures between propylene and the further .alpha.

Abstract: Polymers of propene are prepared by means of a Ziegler-Natta catalyst system composed of (1) a titanium component based on a finely divided shape-dictating silica gel and containing titanium, magnesium, chlorine and a benzenecarboxylic acid derivative, (2) an aluminum component and (3) a silane component, the titanium component (1) being obtained by (1.1) first preparing (I) a carrier material from (Ia) a silica gel, (Ib) an organomagnesium compound (Ic) a gaseous chlorinating agent and (Id) a specific phthalic acid derivative by (1.1.1) first reacting (Ia) with (Ib), then (1.1.2) passing (Ic) into the product of (1.1.1) together with the phthalic acid derivative (Id) and isolating (I), (1.2) preparing a solid-phase intermediate from (I), (II) an alkanol and (III) titanium tetrachloride by (1.2.1) first reacting (I) with (II), then (1.2.2) introducing (III) into the product resulting from (1.2.1), then (1.3) extracting the solid-phase result from (1.

Abstract: Propylene/ethylene block copolymers are prepared by a continuous process in which, in each case in an agitated fixed bed of finely divided polymer from the gas phase, first (I) in a first polymerization zone, propylene is homopolymerized by feeding in a Ziegler-Natta catalyst system consisting of (1) a titanium component which contains titanium, magnesium, chlorine and a phthalic acid derivative, (2) an aluminumalkyl component and (3) a silane component, and (II) in a second polymerization zone, a mixture of propylene and ethylene is polymerized with the propylene homopolymer present in the reaction mixture obtained in the first polymerization zone by feeding in the said reaction mixture. In the process, (A) a titanium component (1) is used which is obtained by a method in which (1.1) first, (1.1.1) in a liquid hydrocarbon, (1.1.2) a finely divided magnesium halide, (1.1.3) an alkanol, (1.1.4) a certain phthalic acid derivative and (1.1.

Abstract: Polymers of propene are prepared using a Ziegler-Natta catalyst system consisting of (1) a titanium component which is based on a finely divided, shape-imparting silica gel and contains titanium, magnesium, chlorine and a benzenecarboxylic acid derivative, (2) an aluminum component and (3) a silane component. In the process, a titanium component (1) is employed which is obtained by (1.1) first preparing (I) a carrier from (Ia) a silica gel which has a relatively high moisture content, (Ib) an organomagnesium compound and (Ic) a gaseous chlorinating agent by a method in which (1.1.1) first (Ia) is reacted with (Ib), (1.1.2) then (Ic) is passed into the mixture obtained in (1.1.1), and (I) is isolated, (1.2) thereafter a solid-phase intermediate is prepared from (I), (II) an alkanol, (III) titanium tetrachloride and (IV) a phthalic acid derivative by a procedure in which (1.2.1) first (I) is reacted with (II), (1.2.2) then (III) is introduced into the mixture resulting from (1.2.

Abstract: Polymers of propene are prepared using a Ziegler-Natta catalyst system consisting of (1) a titanium component which contains titanium, magnesium, chlorine and a benzenecarboxylic acid derivative on a carrier, (2) an aluminum component and (3) a silane component. The process employs a titanium component (1) which is obtained by a method in which (1.1) first a solid-phase intermediate is prepared from (I) magnesium chloride, (II) an alkanol, (III) a carrier which in turn consists of a finely divided inorganic oxide carrier material which has been pretreated with an alkylchlorosilane, (IV) titanium tetrachloride and (V) a phthalic acid derivative, in such a way that (1.1.1) first (I) is reacted with (II), (1.1.2) then the carrier (III) is introduced into the substance resulting from (1.1.1), (1.1.3) thereafter the solid-phase substance resulting from (1.1.2) is reacted with (IV) in a liquid hydrocarbon, with the proviso that (V) is also introduced in (1.1.1) or (1.1.2) or (1.1.3), the (1.