Abstract: A partially crosslinked polymer composition having a melt flow index of from 0.1 to 50 g/10 min at 230.degree. C. under a weight of 2.16 kg and comprisinga) a polymer comprising from 25 to 95% by weight of polypropylene and 5 to 75% by weight of a propylene copolymer with copolymerized C.sub.2 -C.sub.10 -alk-1-enes, the comonomer content being from 1 to 45% by weight, based on the total polymer,b) an organosilane compound of the formula (I)A.sub.4-n SiR.sub.n (i)where A are identical or different acrylates or methacrylates or vinyl groups, R are identical or different C.sub.1 -C.sub.8 -alkoxy or C.sub.1 -C.sub.8 -acetoxy groups, and n is 1, 2 or 3, obtainable by reacting the polymer a) with the organosilane compound b) in the presence of a free-radical initiator and in the presence of a condensation catalyst at from 180.degree. to 280.degree. C., and at from 1 to 100 bar and at a mean residence time of the reaction mixture of from 0.

Abstract: Novel foams having a density of from 0.01 to 0.1 g/cm.sup.3, based on a copolymer comprising ethylene, propylene and a C.sub.4 - to C.sub.8 -.alpha.-olefin, and having a torsion modulus of from 100 to 800 N/mm.sup.2 have high tensile, compressive and flexural strengths and at the same time high elongation at break.

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: Ethylenically unsaturated carboxylic acids and/or carboxylic anhydrides are grafted onto polyolefin blends by a process in which the polyolefin blend consists of from 5 to 49 parts by weight of an ethylene/propylene block copolymer having an ethylene content of less than or equal to 20% by weight and from 51 to 95 parts by weight of a homopolymer or copolymer of ethylene, and the resulting graft copolymer blends are used as adhesion promoters, in particular for polyethylene/adhesion promotor/steel composites, and for the preparation of ionomers.

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.

Abstract: Polymers of polypropylene are prepared by means of a Ziegler-Natta catalyst system comprising (1) a titanium component which contains titanium, magnesium, chlorine and a benzenecarboxylic acid derivative, (2) an aluminum component and (3) a silane component, wherein the (1) used is obtained by (1.1) first reacting with one another (1.1.1) in a liquid hydrocarbon, (1.1.2) a finely divided magnesium halide, (1.1.3) an alkanol, (1.1.4) a phthalic acid ester and (1.1.5) titanium tetrachloride under certain conditions, (1.2) then extracting the solid intermediate obtained from (1.1) with titanium tetrachloride until the remaining solid substance has become significantly richer in magnesium, and (1.3) finally washing the solid substance remaining in (1.2) with an alkane in a certain manner.

Abstract: Polymers of propylene are prepared by means of a Ziegler-Natta catalyst system comprising (1) a titanium component which contains titanium, magnesium, chlorine and a benzenecarboxylic acid derivative, (2) an aluminum component and (3) a silane component, wherein the (1) used is obtained by (1.1) first reacting with one another (1.1.1) in a liquid hydrocarbon, (1.1.2) a finely divided magnesium halide, (1.1.3) an alkanol, (1.1.4) a phthalic acid ester and (1.1.5) titanium tetrachloride under certain conditions, (1.2) then extracting the solid intermediate obtained from (1.1) with a liquid alkylbenzene until the remaining solid substance has become significantly richer in magnesium, and (1.3) finally washing the solid substance remaining in (1.2) with an alkane in a certain manner.