Abstract: A syndiotactic polyolefin is obtained in a high yield by polymerization or copolymerization of an olefin of the formula Ra—CH═CH—Rb in the presence of a catalyst consisting of a metallocene of the formula I in which M1 is titanium, zirconium, vanadium, niobium or tantalum, and an aluminoxane. This polyolefin has a very high molecular weight, a very narrow molecular weight distribution and a very high syndiotactic index. Shaped articles produced from the polymer are distinguished by a high transparency, flexibility, tear resistance and an excellent surface gloss.

Abstract: Process for the preparation of a polyolefin Olefins of the formula R11—CH═CH—R12 (R11, R12=H or C1-C14-alkyl) are polymerized in the presence of a catalyst consisting of at least one metallocene of the formula I (M=zirconium or hafnium) and an aluminoxane. Polymers having a high molecular weight are obtained in a high yield.

Abstract: Isoblock polymers of 1-olefins with a narrow molecular weight distribution are obtained when 1-olefins are polymerized using a catalyst consisting of a chiral metallocene, containing bridges, of formula I: and an aluminoxane. The polymers have rubber-like properties.

Abstract: Olefins of the formula R11—CH═CH—R12 (R11, R12=H or C1-C14-alkyl) are polymerized in the presence of a catalyst consisting of at least one metallocene of the formula I (M=zirconium or hafnium) and an aluminoxane. Polymers having a high molecular weight are obtained in a high yield.

Abstract: A process for the preparation of an olefin polymer by polymerization or copolymerization of an olefin of the formula Ra—CH═CH—Rb, in which Ra and Rb are identical or different and are a hydrogen atom or a hydrocarbon radical having 1 to 14 carbon atoms, or Ra and Rb, together with the atoms connecting them, can form a ring, at a temperature of from −60 to 200° C., at a pressure of from 0.

Abstract: Syndio-isoblock polymers of 1-olefins having molecular chains which contain syndiotactic and isotactic sequences are obtained if the polymerization of the 1-olefins is carried out using a catalyst which is composed of a bridge chiral metallocene of the formula I an an aluminoxane. The polymers have some rubber-like properties.

Abstract: Syndio-isoblock polymers of 1-olefins having molecular chains which contain syndiotactic and isotactic sequences are obtained if the polymerization of the 1-olefins is carried out using a catalyst which is composed of a bridged chiral metallocene of the formula I and an aluminoxane. The polymers have some rubber-like properties.

Abstract: Chemically homogeneous cycloolefin copolymers of polycyclic olefins, such as, for example, norbornene or tetracyclododecene, with cycloolefins and/or acyclic olefins are obtained without ring opening and in a high space-time yield if a catalyst system is used which comprises an aluminoxane and a stereorigid metallocene compound of an element from groups IVb to VIb, of the formula the part of the metallocene molecule formed by M1 and the substituents R16-R17 having C1-symmetry or being in the meso-form.

Abstract: A highly effective catalyst system for the polymerization of olefins comprises a cocatalyst, preferably an aluminoxane, and a metallocene of the formula I ##STR1## where M.sup.1 =Zr or Hf, R.sup.1 and R.sup.2 =(C.sub.1 -C.sub.3)-alkyl or chlorine, R.sup.3, with the proviso that at least one of the radicals R.sup.3 is not hydrogen, is hydrogen, F, Cl, --OR.sup.7, --NR.sup.7 R.sup.8, --P(O)R.sup.7 R.sup.8, --P(OR.sup.7).sub.2 or SR.sup.7, R.sup.4 is a ##STR2## radical, and m plus n are zero or 1.

Abstract: If a catalyst consisting of an aluminoxane and a metallocene of the formula I ##STR1## in particular R.sup.5 R.sup.6 C (Ind).sub.2 or R.sup.5 R.sup.6 C (Ind).sub.2 Zr(CH.sub.3).sub.2, is employed for the polymerization of olefins of the formulaR.sup.9 CH.dbd.CHR.sup.10(R.sup.9, R.sup.10 =H or C.sub.1 -C.sub.28 alkyl), the isotacticity of the polymer wax and hence the hardness and melting point can be varied simply by changing the polymerization temperature, without the molecular weight of the polymer being noticeably changed at the same time.

Abstract: Propylene isoblock polymers with 0.5 to 10 mol %, based on the total polymer, of randomly distributed ethylene content and with a narrow molecular weight distribution and rubber-like properties are obtained when propylene is polymerized using a catalyst comprising an aluminoxane and a chiral metallocene, containing bridges, of formula I: ##STR1## in which M.sup.1 is preferably hafnium or zirconium,R.sup.1 and R.sup.2 are preferably halogen (e.g. C1) atoms,R.sub.3 through R.sup.6 are hydrogen or C.sub.1 -C.sub.10 -alkyl, and pair of adjacent radicals R.sup.3, R.sup.4, R.sup.5, and R.sup.6 can form an aromatic ring with the C-atoms to which they are bonded, andR.sup.7 is preferably --Si(CH.sub.3).sub.2 --Si(CH.sub.3).sub.2 --.

Abstract: Disclosed is a catalyst system and method of polymerizing olefins, wherein the catalyst comprises a bridged metallocene of the following structure: ##STR1## wherein M.sup.1 is a transition metal of groups 4-6, R.sup.1 -R.sup.9 is hydrogen or other groups with the proviso that substituents R.sup.3 and R.sup.6 are not hydrogen, and wherein the metallocene is present in the meso form or in a mixture including both the meso and racemic forms.

Abstract: A process for the preparation of a polyolefin wax If a catalyst consisting of an aluminoxane and a metal-locene of the formula I ##STR1## in particular R.sup.5 R.sup.6 C (Ind).sub.2 or R.sup.5 R.sup.6 C (Ind).sub.2 Zr(CH.sub.3).sub.2, is employed for the polymerization of olefins of the formulaR.sup.9 CH.dbd.CHR.sup.10(R.sup.9, R.sup.10 =H or C.sub.1 -C.sub.28 alkyl), the isotacticity of the polymer wax and hence the hardness and melting point can be varied simply by changing the polymerization temperature, without the molecular weight of the polymer being noticeably changed at the same time.

Abstract: A highly effective catalyst system for the polymerization of olefins comprises a cocatalyst, preferably an aluminoxane, and a metallocene of the formula I ##STR1## where M.sup.1 =Zr or Hf, R.sup.1 and R.sup.2 =(C.sub.1 -C.sub.3)-alkyl or chlorine, R.sup.3, with the proviso that at least one of the radicals R.sup.3 is not hydrogen, =hydrogen, F, Cl, --OR.sup.7, --NR.sup.7 R.sup.8, --P(O)R.sup.7 R.sup.8, --P(OR.sup.7).sub.2 or SR.sup.7, R.sup.

Abstract: The novel metallocenes of the formula I in which, preferably, M1 is Zr or Hf, R1 and R2 are alkyl or halogen, R3 and R4 are hydrogen, R5 and R6 are alkyl or haloalkyl, —(CR8R9)m—R7—(CR8R9)n— is a single- or multi-membered chain in which R7 may also be a (substituted) hetero atom, m+n is zero or 1, and R10 is hydrogen, form, together with aluminoxanes as cocatalysts, a very effective catalyst system for the preparation of polyolefins or high stereospecificity and high melting point. Polyolefins with unique or improved properties are obtained by polymerizing an olefin in the presence of a metallocene combined with a cocatalyst, wherein the metallocene is preferably a zirconocene or a hafnocene, and the Zr or Hf central atom is coordinated with two ligands which are derivatives of 2-substituted indenyl nuclei and which are substituted with at least one and up to four groups (e.g. aliphatic or aromatic groups) on the six-member rings of the indenyl nuclei.

Abstract: The novel metallocenes of the formula I in which, preferably, M1 is Zr or Hf, R1 and R2 are alkyl or halogen, R3 and R4 are hydrogen, R5 and R6 are alkyl or haloalkyl, —(CR8R9)m—R7—(CR8R9)n— is a single- or multi-membered chain in which R7 may also be a (substituted) hetero atom, and m+n is zero or 1, form, together with aluminoxanes as cocatalysts, a very effective catalyst system for the preparation of polyolefins of high molecular weight.

Abstract: A process for the preparation of an olefin polymer by polymerization or copolymerization of an olefin of the formula Ra—CH?CH—Rb, in which Ra and Rb are identical or different and are a hydrogen atom or a hydrocarbon radical having 1 to 14 carbon atoms or Ra and Rb, together with the atoms connecting them, can form a ring, at a temperature of from ?60° to 200° C., at a pressure of from 0.

Abstract: The novel metallocenes of the formula I in which, preferably, M1 is Zr or Hf, R1 and R2 are alkyl or halogen, R3 and R4 are hydrogen, R5 and R6 are alkyl or haloalkyl, —(CR8R9)m—R7—(CR8R9)n— is a single- or multi-membered chain in which R7 may also be a (substituted) hetero atom, m+n is zero or 1, and R10 is hydrogen, form, together with aluminoxanes as cocatalysts, a very effective catalyst system for the preparation of polyolefins of high stereospecificity and high melting point.

Abstract: The novel metallocenes of the formula I in which, preferably, M1 is Zr or Hf, R1 and R2 are alkyl or halogen, R3 and R4 are hydrogen, R5 and R6 are alkyl or haloalkyl, —(CR8R9)m—R7—(CR8R9)n— is a single- or multi-membered chain in which R7 may also be a (substituted) hetero atom, m+n is zero or 1, and R10 is hydrogen, form, together with aluminoxanes as cocatalysts, a very effective catalyst system for the preparation of polyolefins of high stereospecificity and high melting point.

Abstract: A syndiotactic polyolefin is obtained in a high yield by polymerization or copolymerization of an olefin of the formula R.sup.a --CH.dbd.CH--R.sup.b in the presence of a catalyst consisting of a metallocene of the formula I ##STR1## and an aluminoxane. This polyolefin has a very high syndiotactic index. At a low polymerization temperature, a polyolefin having a low average molecular weight and narrow molecular weight distribution is obtained, and at a high polymerization temperature a polymer having a high average molecular weight and a wide molecular weight distribution is obtained.Shaped articles produced from the polymers are distinguished by a high transparency, flexibility, tear strength and excellent surface gloss.