Abstract: The invention relates to a glass fiber-reinforced molding composition composed of an olefin polymer, in particular a propylene polymer. The molding composition comprises an olefin polymer which contains 5-50% by weight of glass fibers which are bonded to the olefin polymer by means of a compatibilizer, and from 10?4 to 1% by weight, preferably from 10?3 to 1031 1% by weight, of a phthalocyanine pigment as the nucleating agent. The low costs and the fact that even a very small fraction of the phthalocyanine pigment in the polymer leads to sufficient nucleation ensures extremely inexpensive production. The nucleation with the phthalocyanine pigment leads to an improvement in the impact strength, and also in the yield stress and tensile strain at break of the molding composition.

Abstract: The invention relates to a glass fiber-reinforced molding composition composed of an olefin polymer, in particular a propylene polymer. The molding composition comprises an olefin polymer which contains 5-50% by weight of glass fibers which are bonded to the olefin polymer by means of a compatibilizer, and from 10?4 to 1% by weight, preferably from 10?3 to 1031 1% by weight, of a phthalocyanine pigment as the nucleating agent. The low costs and the fact that even a very small fraction of the phthalocyanine pigment in the polymer leads to sufficient nucleation ensures extremely inexpensive production. The nucleation with the phthalocyanine pigment leads to an improvement in the impact strength, and also in the yield stress and tensile strain at break of the molding composition.

Abstract: A belt tensioning device for traction mechanisms includes a receiving and mounting housing, a pulley carrier pivotally connected to the receiving and mounting housing, a bearing supporting the pulley carrier relative to the receiving and mounting housing, and a spring located between the pulley carrier and the receiving and mounting housing for applying the tensioning force. The belt tensioning device, in normal operation, on the slack side between a generator and a main pulley can also be used when the slack side becomes the load side by a blocking mechanism which enables swinging motion of the pulley carrier relative to the receiving and mounting housing in a first direction, and limits or prevents such motion in a second, opposite direction.

Abstract: A belt tensioning device for traction mechanisms includes a receiving and mounting housing, a pulley carrier pivotally connected to the receiving and mounting housing, a bearing supporting the pulley carrier relative to the receiving and mounting housing, and a spring located between the pulley carrier and the receiving and mounting housing for applying the tensioning force. The belt tensioning device, in normal operation, on the slack side between a generator and a main pulley can also be used when the slack side becomes the load side by a blocking mechanism which enables swinging motion of the pulley carrier relative to the receiving and mounting housing in a first direction, and limits or prevents such motion in a second, opposite direction.

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: A talc-reinforced polypropylene molding composition with high impact strength comprising a) from 35 to 90% by weight of a propylene polymer (A) with a melt flow rate of from 15 to 100 g/10 min at 230° C. and under a load of 2.16 kg in accordance with ISO 1133 and a content of from 0 to 25% by weight of other C2-C10 1-alkenes, b) from 5 to 40% by weight of an ethylene polymer (B) with from 20 to 30% by weight of copolymerized C4-C10 1-alkenes, a melt flow rate of from 0.2 to 30 g/10 min at 190° C. and under a load of 2.16 kg in accordance with ISO 1133, a density of from 0.850 to 0.880 g/cm3 and a Mooney viscosity (MS 1+4; 121° C.) of from 5 to 50 in accordance with DIN 53523/T1, and c) from 5 to 25% by weight of talc whose average particle size by the Sedigraph method is from 1.0 to 10 &mgr;m.

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: Metallocenes containing aryl-substituted indenyl derivatives as ligands, process for their preparation, and their use as catalysts.

Abstract: A very effective catalyst system for the polymerization or copolymerization of olefins comprises a cocatalyst, preferably an aluminoxane or a supported aluminoxane, and a metallocene of the formula I in which, in the preferred form, M1 is Zr or Hf, R1 and R2 are halogen or alkyl, R3 is alkyl, R4 to R12 are alkyl or hydrogen and R13 is a (substituted) alkylene or heteroatom bridge. The metallocenes, in particular the zirconocenes, produce polymers of a very high molecular weight, in the case of prochiral monomers polymers of a very high molecular weight, very high stereoactivity and very high melting point, at high catalyst activities in the industrially particularly interesting temperature range between 50 and 80° C. In addition, reactor deposits are avoided by means of supported catalyst systems.

Abstract: A very effective catalyst system for the polymerization or copolymerization of olefins comprises a cocatalyst, preferably an aluminoxane or a supported aluminoxane, and a metallocene of the formula I in which, in the preferred form, M1 is Zr or Hf, R1 and R2 are halogen or alkyl, R3 is alkyl, R4 to R12 are alkyl or hydrogen and R13 is a (substituted) alkylene or heteroatom bridge. The metallocenes, in particular the zirconocenes, produce polymers of very high molecular weight, in the case of prochiral monomers polymers of very high molecular weight, very high stereotacticity and very high melting point, at high catalyst activities in the industrially interesting temperature range between 50 and 80° C.

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: 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.