Abstract: The invention relates to a process for preparing racemic metallocene complexes by reacting transition metal complexes with cyclopentadienyl derivatives of alkali metals or alkaline earth metals and heating the reaction mixture obtained in this way to a temperature in the range from ?78 to 250° C., to the corresponding metallocene complexes themselves and to their use as catalysts or as constituents of catalysts for the polymerization of olefinically unsaturated compounds or as reagents or catalysts in stereoselective synthesis.

Abstract: The invention relates to a method for producing racemic metallocene complexes by reacting bridged or non-bridged transition metal complexes with cyclopentadienyl derivatives of alkaline or alkaline earth metals and optionally, subsequently substituting the phenolate ligands.

Abstract: A process for purifying metallocenes in which a sparingly soluble metallocene halide is converted into a readily soluble and readily crystallizable metallocene by replacement of at least one halide ligand by an alternative negatively charged ligand and the metallocene obtained in this way is subsequently purified by crystallization.

Abstract: A free-flowing solid which does not self-ignite, comprising: a) at least one support component, b) at least one chemical compound which per se is self-igniting, c) at least one inert liquid and d) further components.

Abstract: The catalyst systems comprise as active constituents a) a titanium-containing solid component comprising a compound of titanium, a compound of magnesium, a halogen, an inorganic oxide as support and a carboxylic ester as electron donor compound, and also, as cocatalyst, b) an aluminum compound and c) optionally a further electron donor compound, wherein the inorganic oxide used has a pH of from 1 to 6, an average particle diameter of from 5 to 200 &mgr;m, an average primary particle diameter of from 1 to 20 &mgr;M and voids or channels having an average diameter of from 0.1 to 20 &mgr;m and a macroscopic share of the volume of the overall particle within the range from 5 to 30%.

Abstract: Multiphase homo- or copolymers of C2-C10-alk-1-enes are prepared by a process in which polymerization is effected in the presence of two different catalyst systems in one reaction zone, one of the catalyst systems containing, as active components, a metallocene complex of the general formula (I) or (II) where M1 is a metal of group IVb, Vb or VIb of the Periodic Table, R1 and R2 are identical or different and are each hydrogen, C1-C10-alkyl, C1-C10-alkoxy, C6-C10-aryl, C6-C10-aryloxy, C2-C10-alkenyl, C7-C40-arylalkyl, C7-C40-alkylaryl, C8-C40-arylalkenyl or halogen, R3 and R4 are identical or different and are each hydrogen, halogen, C1-C10-alkyl which may be halogenated, C6-C10-aryl or an —NR210, —SR10, —OSiR310, —SiR310 or —PR210 radical, where R10 is halogen, C1-C10-alkyl or C6-C10-aryl, and R5 and R6 are identical or different and have the meanings stated for R3 and R4, with the proviso that R5 and R6 are not hydrogen.

Abstract: A process for preparing random propylene copolymers containing copolymerized C.sub.2 -C.sub.10 -alk-1-enes by polymerization of propylene and C.sub.2 -C.sub.10 -alk-1-enes in the presence of a Ziegler-Natta catalyst system comprising a titanium-containing solid component a) comprising a compound of magnesium, a halogen, silica gel as support and a carboxylic ester as electron donor compound, and also, as cocatalysts, an aluminum compound b) and a further electron donor compound c), where propylene and the C.sub.2 -C.sub.10 -alk-1-enes are polymerized with one another at from 50 to 100.degree. C. at pressures in the range from 15 to 40 bar and mean residence times of from 0.5 to 5 hours and the support used in the titanium-containing solid component is a silica gel which has a mean particle diameter of from 5 to 200 .mu.m, a mean particle diameter of the primary particles of from 1 to 10 .mu.m and voids or channels having a mean diameter of from 1 to 10 .mu.

Abstract: A connector assembly comprises a mounting portion for mounting the connector to a complementary portion which could be either another connector or a member fixed to a structure such as an automobile's bodywork. The mounting portions comprise interengaging T-shaped walls and T-shaped profiles that are longitudinally slidably interengaged. The mounting portion walls comprise interleaving recesses and extensions and that enable the mounting portions to be interengaged by placing the mounting portions one against each other and then sliding them in opposing directions by only a short travel. The latter enables longitudinally slidable T-profiles to be used but nevertheless over short travel which is advantageous for certain applications to reduce cable length surplus.

Abstract: Propylene polymers which comprise from 25 to 97% by weight of a propylene polymer (I) containing from 0 to 15% by weight of copolymerized C.sub.2 -C.sub.10 -alk-1-enes and also comprise from 3 to 75% by weight of a further propylene polymer (II) containing from 15 to 80% by weight of copolymerized C.sub.2 -C.sub.10 -alk-1-enes, are obtainable by two-stage polymerization of propylene and C.sub.2 -C.sub.10 -alk-1-enes in the presence of a Ziegler-Natta catalyst system which comprises a titanium-containing solid component a) comprising a compound of magnesium, a halogen, silica gel as support and a carboxylic ester as electron donor compound, and also as cocatalysts an aluminum compound b) and a further electron donor compound c), where, in a first polymerization stage, propylene is polymerized in the presence or absence of further C.sub.2 -C.sub.10 -alk-1-enes at from 50.degree. to 100.degree. C., pressures in the range from 15 to 40 bar and a mean residence time of from 0.

Abstract: Random propylene copolymers containing copolymerized C.sub.2 -C.sub.10 -alk-1-enes are obtainable by polymerization of propylene and C.sub.2 -C.sub.10 -alk-1-enes in the presence of a Ziegler-Natta catalyst system comprising a titanium-containing solid component a) comprising a compound of magnesium, a halogen, silica gel as support and a carboxylic ester as electron donor compound, and also, as cocatalysts, an aluminum compound b) and a further electron donor compound c), where propylene and the C.sub.2 -C.sub.10 -alk-1-enes are polymerized with one another at from 50.degree. to 100.degree. C. at pressures in the range from 15 to 40 bar and mean residence times of from 0.5 to 5 hours and the support used in the titanium-containing solid component is a silica gel which has a mean particle diameter of from 5 to 200 .mu.m, a mean particle diameter of the primary particles of from 1 to 10 .mu.m and voids or channels having a mean diameter of from 1 to 10 .mu.

Abstract: Highly flexible propylene/ethylene copolymers having a high rubber content are obtainable by two-stage polymerization from the gas phase in an agitated fixed bed by means of a Ziegler-Natta catalyst system which, in addition to a titanium-containing solid component, also contains an aluminum compound as a cocatalyst, in a first polymerization stage, propylene being polymerized at from 15 to 40 bar and from 50.degree. to 90.degree. C. and during an average residence time of the reaction mixture of from 0.5 to 5 hours and then, in a second polymerization stage, a mixture of propylene and ethylene being polymerized with the polymer discharged from the first polymerization stage, at from 5 to 30 bar, this pressure being at least 2 bar below the pressure of the first polymerization stage, and at from 60.degree. to 100.degree. C. and during an average residence time of the reaction mixture of from 0.

Abstract: A process for the preparation of Ziegler-Natta type catalyst systems, containing, as active constituentsa) a titanium-containing solid component, which contains in addition to a compound of titanium at least one electron donor compound, and is present in an inert solvent in the form of a suspension, and, as co-catalyst,b) an aluminum compound andc) optionally further electron donor compoundsin which, following the preparation of the titanium-containing solid component a), the inert solvent present in the suspension is removed by first filtering the suspension in a first step, and then removing further solvent from the filtered material in a second step by applying a pressure difference at temperatures of not more than 100.degree. C.

Abstract: Propylene polymers containA) a semicrystalline propylene homopolymer having a melting point of 125 to 165.degree. C. and a glass transition temperature which is greater than -10.degree. C. andB) a semicrystalline propylene homopolymer having a melting point below 130.degree. C. and a glass transition temperature which is less than or equal to -10.degree. C. or a non-crystallizing propylene homopolymer having a glass transition temperature which is less than or equal to -10.degree. C.