Abstract: A process for polymerizing one or more alpha-olefins of formula CH2?CHT wherein T is a hydrogen atom or a C1-C20 alkyl radical comprising the following steps: a) contacting in a continuous way one or more of said alpha olefins with a metallocene based catalyst system in a loop reactor, wherein: (i) the reaction is carried out in a liquid medium; (ii) the average residence time of the metallocene-based catalyst system is not more than 30 minutes; (iii) the temperature of the loop ranges from 25° to 70° C.; in to obtain a polymerization degree ranging from 60 to 500 g per gram of catalyst system; b) feeding in continuous the prepolymerized metallocene-based catalyst system obtained in step a) into a polymerization reactor C) polymerizing one or more alpha-olefins, the same or different from the alpha olefins used in step a), in the presence of said prepolymerized metallocene-based catalyst system.

Abstract: A process for the preparation of indanones of the formula II from indanones of the formula I or of indanones of the formula IIa from indanones of the formula Ia comprises reacting an indanone of the formula I or Ia with a coupling component.

Abstract: The present invention relates to a process for preparing a catalyst solid for olefin polymerization, comprising a finely divided support, an aluminoxane and a metallocene compound, which comprises a) firstly combining the finely divided support with the aluminoxane and subsequently b) adding the reaction product of a metallocene compound with at least one organometallic compound to the modified support, catalyst solids obtainable by this process, catalyst systems comprising these catalyst solids, their use for the polymerization of olefins and a process for the polymerization of olefins.

Abstract: A process for the polymerization of olefins, in particular a process for the copolymerization of propylene with further olefins, is carried out in the presence of highly active catalyst systems comprising specifically selected metallocenes, in particular ones which bear different substituents in position 2 position 4 on an indenyl ligand. Novel polypropylene copolymers can be obtained by this process.

Abstract: The present invention relates to a process for preparing a catalyst for olefin polymerization which is obtainable by bringing A) at least one organic transition metal compound, B) a mixture of at least two different organo metallic compounds and C) at least one cation-forming compound into contact with one another, wherein the organic transition metal compound A) is firstly brought into contact with the mixture of the organo metallic compounds B). In addition, the invention relates to the use of the catalyst for olefin polymerization, to catalysts obtainable by this process and to a process for the polymerization of olefins in which these catalysts are used.

Abstract: A process for the preparation of indanones of the formula II from indanones of the formula I or of indanones of the formula IIa from indanones of the formula Ia comprises reacting an indanone of the formula I or Ia with a coupling component.

Abstract: Catalyst system for olefin polymerization comprising A) at least one calcined hydrotalcite, B) at least one organic transition metal compound, C) optionally one or more cation-forming compounds and D) at least one organic magnesium compound.

Abstract: A catalyst solid comprising: A) support particles having a mean particle diameter d50 of from 5 to 200 ?m and a specific surface area of from 30 to 1 000 m2/g and obtainable by agglomeration of primary particles of a pyrogenic silica having a mean particle diameter dm of from 1 to 50 nm, and B) at least one organic transition metal compound, can be used for the polymerization or copolymerization of olefins.

Abstract: A process for the preparation of indanones of the formula II from indanones of the formula I or of indanones of the formula IIa from indanones of the formula Ia comprises reacting an indanone of the formula I or Ia with a coupling component.

Abstract: Propylene polymers containing from 0 to 2.5% by weight of C2-C10-olefin comonomers have an Mw of from 350,000 to 1,000,000 g/mol, an Mw/Mn of from 4 to 10, a proportion by weight of the polymer fraction having a viscosity number of from 500 to 1400 ml/g of from 20 to 80% of the total polymer and a proportion by weight of a polymer fraction having a viscosity number of from 200 to 400 ml/g of from 80 to 20% of the total polymer and an isotactic sequence length of from 50 to 100.

Abstract: Catalyst system for olefin polymerization comprising

Abstract: Catalyst solid for olefin polymerization comprising

Abstract: A process for the polymerization of olefins, in particular a process for the copolymerization of propylene with further olefins, is carried out in the presence of highly active catalyst systems comprising specifically selected metallocenes, in particular ones which bear different substituents in position 2 and position 4 on an indenyl ligand. Novel polypropylene copolymers can be obtained by this process.

Abstract: A process for the preparation of indanones of the formula II from indanones of the formula I or of indanones of the formula IIa from indanones of the formula Ia 1

Abstract: a process for the preparation of indanones of the formula II from, indanones of the formula I or of indanones of the formula IIa from indanones of the formula Ia comprises reacting an indanone of the formula I or Ia with a coupling component.

Abstract: Disclosed are compounds of the following core structure, and their use as polymerization catalysts: wherein M1 is a group lVb transition metal, R5 is a substituted aryl group, and Ra forms a heteroatom-containing ring fused to the cyclopentadienyl ring.

Abstract: The invention relates to a catalyst system obtained by mixing at least one metallocene, at least one co-catalyst and at least one support which is rendered inert. The invention further relates to a method for producing a free flowing supported catalyst system wherein a) a metallocene/co-catalyst mixture is produced in a solvent or suspension agent, b) the metallocene/co-catalyst mixture is applied to a porous preferably inorganic dehydrated support, c) the solvent is removed from the resulting mixture, d) the supported catalyst system is isolated. The present invention also relates to homopolymers and/or copolymers having the preferred formula Rm—CH═CH—Rn for the monomer, wherein Rm and Rn are the same or different and mean a hydrogen atom or a group containing carbon with 1 to 10 C atoms, and Rm and Rn can form one or several rings with the binding atoms, which can be obtained with a catalyst system.

Abstract: The invention relates to a method for producing rac/meso metallocenes, the rac/meso metallocenes themselves, and their use in the production of polyolefins.

Abstract: A process for preparing rac/meso-metallocenes, the rac/meso-metallocenes themselves and the use of the rac/meso-metallocenes for preparing isotactic polyolefins are described.

Abstract: The present invention relates to a metallocene of the formula I, ##STR1## for preparing polyolefins, where M.sup.1 is preferably Zr, Hf or Ti, R.sup.1 and R.sup.2 are each a hydrogen atom, a C.sub.1 -C.sub.3 -alkyl group, a C.sub.1 -C.sub.3 -alkoxy group, a C.sub.6 -C.sub.8 -aryl group, a C.sub.6 -C.sub.8 -aryloxy group, a C.sub.2 -C.sub.4 -alkenyl group, a C.sub.7 -C.sub.10 -arylalkyl group, a C.sub.7 -C.sub.12 -alkylaryl group, a C.sub.8 -C.sub.12 -arylalkenyl group or chlorine, R.sup.3 is a chlorine atom, a C.sub.1 -C.sub.3 -alkyl group, a C.sub.2 -C.sub.4 -alkenyl group, a C.sub.6 -C.sub.8 -aryl group, an NR.sup.16.sub.2, SR.sup.16, OSiR.sup.16.sub.3, SiR.sup.16.sub.3 or PR.sup.16.sub.2 radical where R.sup.16 is chlorine, a C.sub.1 -C.sub.4 -alkyl group or a C.sub.6 -C.sub.8 -aryl group. R.sup.4 is a hydrogen atom, R.sup.13 is --(R.sup.14 M.sup.2 R.sup.15)--, --(R.sup.14 CR.sup.15)--(R.sup.14 CR.sup.15)--, --(R.sup.14 CR.sup.15)--(R.sup.14 M.sup.2 R.sup.15)-- or --(R.sup.14 CR.sup.15)--, where R.sup.