Abstract: In a method of measuring the fill level of a reactor in continuously operated polymerization processes using measurement of the respective phase interface in the reactor by means of ionizing radiation, at least one measuring unit comprising a radiation source which emits ionizing radiation and a corresponding detector is brought to the phase interface in the reactor and flexibly installed there, with the fill level of the reactor being measured by determining the phase interface by means of the radioactive backscattering measurement.

Abstract: A process for producing from propylene, ethylene and/or C4-C18-alk-1-enes a fiber grade propylene polymer in which not less than 90 mol % of the units derived from monomers are derived from propylene and which has a polydispersity index PDI of not more than 2.2, where PDI is MW/MN, where MW is the weight average molar mass and MN is the number average molar mass and both are determined by gel permeation chromatography (GPC) at 145° C. in 1,2,4-trichlorobenzene, by polymerizing the monomers by means of a metallocene catalyst system, comprises subsequently degrading said propylene polymer peroxidically or thermally.

Abstract: In a process for preparing a metal-containing supported catalyst or a metal-containing supported catalyst component by impregnation of a support material with an impregnation solution comprising the metal component, the impregnation solution flows through the support material.

Abstract: A semicrystalline propylene polymer composition with good suitability for producing biaxially oriented films and prepared by polymerizing propylene, ethylene and/or C4-C18-1-alkenes, where at least 50 mol % of the monomer units present arise from the polymerization of propylene. Also described is the use of the semicrystalline propylene polymer composition for producing films, fibers or moldings, the films, fibers and moldings made from these compositions, biaxially stretched films made from the semicrystalline propylene polymer compositions, and also a method for characterizing the semicrystalline propylene polymer compositions.

Abstract: The invention relates to a method for producing a supported catalyst which contains metal, or a supported catalyst constituent which contains metal by impregnating a supporting material with an impregnating solution containing the metal constituent, whereby the impregnating solution flows through the supporting material.

Abstract: Propene terpolymers consist of from 80 to 99.5 mol % of structural units derived from propene, from 0.1 to 15 mol % of structural units derived from ethene or a C4-C6-1-olefin (I) and from 0.

Abstract: A sealable coextruded film is made from at least one outer layer and from at least one base layer, where the outer layer is composed of a propylene terpolymer comprising from 80 to 99.5 mol % of structural units derived from propylene, from 0.2 to 15 mol % of structural units derived from ethene or from a C4-C6 1-olefin (I) and from 0.3 to 15 mol % of structural units derived from another C4-C12 1-olefin (II) different from the C4-C6 1-olefin (I), and where the propylene terpolymer has been prepared using metallocene catalysts.

Abstract: In a process for the polymerization of C2-C8-alk-1-enes by means of a Ziegler-Natta catalyst system, in which polymerization is carried out from the gas phase in at least one reaction zone at from 40 to 120° C. and pressures of from 1 to 100 bar, the pressure and temperature in the reaction zone are set so that an operating point formed by these parameters in a pressure-temperature diagram is located at from 0.2 to 5.0 bar below the dew line of the respective reaction mixture above which condensation of the C2-C8-alk-1-enes occurs.

Abstract: Propylene polymers containing a matrix of a propylene homopolymer and a copolymer of propylene and other alkenes, wherein, during the separation of the propylene polymers according to tacticity and comonomer distribution of the polymer chains, by first dissolving the propylene polymers in boiling xylene, then cooling the solution at a cooling rate of 10° C./h to 25° C. and thereafter, increasing the temperature, separating the propylene polymers into fractions of different solubility, either one or more of the conditions that i) more than 20% by weight of the matrix remain undissolved on further heating to 112° C. or ii) more than 8% by weight of the matrix remain undissolved on further heating to 117° C. or iii) more than 1% by weight of the matrix remain undissolved on further heating to 122° C. are fulfilled by the matrix which remains undissolved on heating the cooled propylene polymer solution to 80° C.

Abstract: Random copolymers of propylene with other 1-alkenes having up to 10 carbon atoms,

Abstract: Transition metal complexes of the formula (Ia) or (Ib), in which the substituents and indices have the following meanings: M is titanium, zirconium, hafnium, vanadium, niobium or tantalum or an element of the third subgroup of the Periodic Table or of the lanthanoids, X is fluorine, chlorine, bromine, iodine, hydrogen, C1-C10-alkyl, C6-C15-aryl, alkylaryl having 1 to 10 carbon atoms in the alkyl radical and 6 to 20 carbon atoms in the aryl radical, —OR5 or —NR5R6, n is 1, 2 or 3, where n is the valency of M minus the number 2, Z is a three-way bridge and A and A1 are two-way bridges.

Abstract: Propylene polymers containing a matrix of a propylene homopolymer and a copolymer of propylene and other alkenes, wherein, during the separation of the propylene polymers according to tacticity and comonomer distribution of the polymer chains, by first dissolving the propylene polymers in boiling xylene, then cooling the solution at a cooling rate of 10° C./h to 25° C.

Abstract: A process for preparing a supported transition metal catalyst comprising a particulate organic or inorganic support material, a transition metal complex and a compound capable of forming metallocenium ions comprises the following process steps: a) contacting a solution of a compound capable of forming metallocenium ions with a second solvent in which this compound is only sparingly soluble, in the presence of the support material, b) removing at least part of the solvent from the support material and c) contacting a solution of a mixture of a compound capable of forming metallocenium ions and a transition metal complex with a second solvent in which this mixture is only sparingly soluble, in the presence of the support material obtained as described in a) and b).

Abstract: A semicrystalline propylene polymer composition with good suitability for producing biaxially oriented films and prepared by polymerizing propylene, ethylene and/or C4-C18-1-alkenes, where at least 50 mol % of the monomer units present arise from the polymerization of propylene,

Abstract: Polymers of propene consist of from 50 to 99.9% by weight of an isotactic propene copolymer (A′) and from 0.1 to 50% by weight of a propene homopolymer or a propene copolymer (B′), where a) the propene copolymer (A′) consists of from 80 to 99.9 mol % of propene and from 0.1 to 20 mol % of ethene and/or a C4-C12-1-olefin, at least 80% of all propene diads are isotactic meso diads, the propene copolymer (A′) has a proportion (XS) of material soluble in xylene at 20° C. which satisfies the inequality (1) (XS)<542 400 exp (−0.1TM)+0.5  (1),  the tensile modulus of elasticity (E) of the propene copolymer (A′) in MPa, determined in accordance with ISO 527, obeys the inequality (2) (E)>1.9×10−11(TM)6.34+180 MPa  (2),  where in both inequalities (1) and (2) TM is the melting point in ° C.

Abstract: Random copolymers of propylene with ethylene and at least one C4-C10-alk-1-ene, having a melting point, determined by the DSC method, of less than or equal to 135° C., are obtainable by polymerization of propylene, ethylene and at least one C4-C10-alk-1-ene in the absence of a liquid reaction medium from the gas phase at from 50 to 100° C. and a pressure of from 15 to 40 bar in the presence of a Ziegler-Natta catalyst system comprising a) a titanium-containing solid component comprising at least one halogen-containing magnesium compound, an electron donor and an inorganic oxide as support, b) an aluminum compound and c) a further electron donor compound, wherein the ratio of the partial pressures of propylene and ethylene is set to from 20:1 to 100:1 and the ratio of the partial pressures of the C4-C10-alk-1-ene(s) and ethylene is set to from 2.5:1 to 20:1. A process for preparing such random copolymers is also provided, and they can be used in films, fibers or moldings.

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: C2-C8-Alk-1-enes are polymerized by means of a Ziegler-Natta catalyst system in a reactor cascade comprising at least two reactors, a homo- or copolymer of C2-C8-alk-1-enes being prepared in a reactor RA, upstream of which one or more further reactors may be connected, the reaction mixture being discharged from RA and transferred to a subsequent reactor RB and the polymerization in RB and in the reactors which may be connected to RB being carried out in the presence of a liquid or dissolved regulator for regulating the catalyst activity, by a process in which the regulator is added to the reaction mixture after discharge from RA and before entry into RB, and an apparatus for polymerizing C2-C8-alk-1-enes by means of the novel process is described.

Abstract: In catalyst systems of the Ziegler-Natta type modified during their preparation and comprising as active constituentsa) a titanium-containing solid component which is obtained by reacting a compound of titanium with a compound of magnesium, a halogen, an inorganic oxide as support, a C.sub.1 -C.sub.8 -alkanol and a carboxylic ester as electron donor compound,and also as cocatalystb) an aluminum compound andc) if desired, a further electron donor compound,the titanium-containing solid component a) is prepared by first, in a first stage, admixing an inorganic oxide as support with a solution of a chlorine-free compound of magnesium in an inert solvent, stirring this mixture for from 0.5 to 5 hours at from 10 to 120.degree. C. and subsequently reacting it while stirring continually in an inert solvent with a C.sub.1 -C.sub.8 -alkanol in an at least 1.

Abstract: A process and apparatus for the measurement of parameters in reactors having moving stirrers which contain probes in the reactor interior, wherein at least two probes connected via a multiplexer to a sensor signal amplifier by connecting cables located in the moving stirrers are installed on the surface of the moving stirrers, and the measurement data obtained by the probes are passed via the connecting cables to a sensor signal amplifier and from thence are passed on to an electronic evaluation unit by non-contact, inductive signal transmission by means of a contactless sensor tap.