Abstract: The present invention relates to high molecular weight homopolymers and copolymers of ethene, which homopolymer or copolymer is obtained by polymerizing the monomer(s) at a temperature of from 70.degree. to 150.degree. C. and under a pressure of from 2 to 150 bar in contact witha chromium trioxide catalyst,(1) loading a support based on silicon dioxide with(2) either chromium trioxide or a chromium compound capable of being converted to chromium trioxide under the conditions of stage (3) below and then(3) heating the resulting intermediate in a gas stream containing oxygen,the support (1) being a special silica xerogel obtained by extracting not more than 30% of the water from a silica hydrogel by means of an alkanol, an alkanone or a mixture thereof followed by drying, comminution and fractional screening.

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: Carboxyl-containing isobutene copolymers are obtainablea) by cationic polymerization of a mixture of from 1 to 99 mol % of isobutene and from 99 to 1 mol % of a 2-methylalk-1-ene at less than 20.degree. C. in the presence of a halogen-containing Lewis acid andb) subsequent grafting of the isobutene copolymer obtainable in this manner with an .alpha.,.beta.-ethylenically unsaturated carboxylic acid or carboxylic acid derivative at above 100.degree. C. and in the presence of a free radical initiator.Such carboxyl-containing isobutene copolymers are particularly suitable as adhesive raw materials or as sealing compounds.

Abstract: Carboxyl-containing isobutene copolymers are obtainablea) by cationic polymerization of a mixture of from 1 to 99 mol % of isobutene and from 99 to 1 mol % of a 2-methylalk-1-ene at less than 20.degree. C. in the presence of a halogen-containing Lewis acid andb) subsequent grafting of the isobutene copolymer obtainable in this manner with an .alpha.,.beta.-ethylenically unsaturated carboxylic acid or carboxylic acid derivative at above 100.degree. C. and in the presence of a free radical initiator.Such carboxyl-containing isobutene copolymers are particularly suitable as adhesive raw materials or as sealing compounds.

Abstract: In a novel process for the preparation of a supported catalyst for the polymerization of .alpha.-olefins, a carrier gel (1) is first prepared by a method in which a sodium or potassium waterglass solution is introduced into a stream of an aqueous mineral acid which is subjected to angular momentum and may contain aluminum ions, longitudinally and tangentially to the stream, the resulting silica hydrosol sprayed in the form of drops into a gaseous medium and allowed to solidify into a hydrogel, and the resulting hydrogel is freed from salts by washing without prior aging and, if necessary, freed from some of the water by extraction with alcohols and/or ketones and is then dried. This gives the carrier gel (1), which is milled and is fractionated according to particle size. In a second process step, the carrier gel (1) is laden with chromium trioxide or with a chromium compound which can be converted into chromium trioxide, after which the resulting chromium-containing carrier gel (2) is heated at from 400.

Abstract: The present invention relates to a novel catalyst for the preparation of high molecular weight homopolymers and copolymers of ethene, which catalyst is obtainable by(1) loading a support based on silicon dioxide with(2) either chromium trioxide or a chromium compound capable of being converted to chromium trioxide under the conditions of stage (3) below and then(3) heating the resulting intermediate in a gas stream containing oxygen.the support (1) being a special silica xerogel obtained by extracting not more than 30% of the water from a silica hydrogel by means of an alkanol, an alkanone or a mixture thereof followed by drying, comminution and fractional screening.

Abstract: A process for the continuous preparation of finely divided homopolymers and copolymers of ethene by catalytic polymerization in a circular tube reactor using a liquid alkane as reaction medium in which the ethene or ethene/comonomer mixture to be polymerized is present in dissolved form and the polymer formed is present in suspended form and running the reaction mixture as a cycle stream to which the feed materials are added by bleeding in and from which the polymer formed is withdrawn by bleeding out reaction mixture, comprising (a) maintaining the mean concentration C.sub.m of polymer in the cycle stream at a value within a certain range and (b) effecting the bleeding out of reaction mixture at a point of the cycle stream at which the concentration of polymer has a value which is lower than the mean concentration C.sub.m by a distinct and definite amount.

Abstract: The conversion is increased in the preparation of polyisobutylene by polymerization of isobutylene in a polymerization zone at from 0.degree. to -130.degree. C. in the presence of from 0.01 to 1.0% by weight of a boron trifluoride catalyst, from 0.001 to 1.0% by weight of a molecular weight regulator and from 30 to 90% by weight of a low-boiling solvent which is inert under the reaction conditions, by a process in which the content of but-1-ene in the monomeric isobutylene is kept constant at from 1.9 to 2.1, in particular 2.0, % by weight.

Abstract: An apparatus for carrying out polymerizations from the gas phase comprising a sealable reactor with a spiral stirrer which is rotatable in the reactor about a vertical axis to generate circulatory streams of the materials employed, in which the stirrer rotating within the reactor is surmounted by a stirrer rod, which extends upward beyond the uppermost flight circle of the stirrer and is attached to the stirrer at a certain distance from the axis of the stirrer, the distance of the side face of the stirrer rod from the reactor wall is at least 10 mm, and the surface of revolution of the moving rod matches the contour of the reactor in this zone.

Abstract: Manufacture of polymers of .alpha.-monoolefins by polymerization with a Ziegler catalyst system comprising (1) a catalyst component containing titanium and/or vanadium and (2) a particular compound of the metals aluminum, magnesium or zinc. The characteristic feature of the process according to the invention is that the catalyst component (1) containing titanium and/or vanadium is the solid-phase product (VII) contained by first (1.1) bringing a finely divided porous inorganic oxidic material (I), which has the formula Al.sub.2 O.sub.3 or SiO.sub.2.aAl.sub.2 O.sub.3, where a is a number from 0 to 2, into contact with an aluminum compound (II) dissolved in an organic solvent, to form a solid-phase product (III), then (1.2) bringing the solid-phase product (III) obtained in stage (1.1) into contact with a magnesium compound (IV), dissolved in an organic solvent, to form a solid-phase product (V), and finally (1.3) bringing the solid-phase product (V) obtained in stage (1.

Abstract: A process for the manufacture of homopolymers and copolymers of .alpha.-monoolefins of 2 to 6 carbon atoms by polymerizing the monomer or monomers by means of a Ziegler catalyst system comprising (1) a catalyst component containing titanium and (2) a particular compound of aluminum, magnesium or zinc, the atomic ratio of titanium from catalyst component (1) to metal (Me) from catalyst component (2) being from 1 : 0.1 to 1 : 500, wherein the titanium-containing catalyst component (1) employed is the solid-phase product (VI) obtained by (1.1) first bringing into contact (1.1.1) a particular finely divided, porous, inorganic oxidic material (I) and (1.1.2) a particular aluminum compound (II) dissolved in an organic solvent, to form a solid-phase product (III) and (1.2) then bringing into contact (1.2.1) the solid-phase product (III) obtained from stage (1.1) and (1.2.2) a solution (IV) which is obtained on bringing together (IVa) 100 parts by weight of a particular alcohol, (IVb) from 0.

Abstract: A process for the manufacture of homopolymers and copolymers of .alpha.-monoolefins of 2 to 6 carbon atoms by polymerizing the monomer or monomers by means of a Ziegler catalyst system comprising (1) a catalyst component containing titanium and (2) a particular compound of the metals aluminum, magnesium or zinc, the atomic ratio of titanium from catalyst component (1) to metal from catalyst component (2) being from 1:0.1 to 1:500, wherein the titanium-containing catalyst component (1) employed is the solid-phase product (IV) obtained by bringing into contact (1.1) a finely divided, porous, inorganic oxidic material (I) which has the formula SiO.sub.2 . aAl.sub.2 O.sub.3 --, where a is a number from 0 to 2, and (1.2) a solution (II) formed on bringing together (IIa) 100 parts by weight of an alcohol of the general formula Z--OH, where Z is a saturated hydrocarbon radical of 1 to 8 carbon atoms, (IIb) from 0.01 to 6 parts by weight (calculated as titanium) of a titanium trihalide and (IIc) from 0.

Abstract: Particulate polymers of ethylene are prepared by polymerization of ethylene or ethylene/.alpha. -monoalkene mixtures in a dry agitated bed (B) of the particulate polymer by means of a Ziegler/Natta catalyst system consisting of (1) a titanium-containing component and (2) an aluminum-containing component, the said components (1) and (2) being separately fed to the bed (B). Component (1) is a particulate reaction product (U) (of) (1.1) a substance of the formula TiCl.sub.3 . (AlCl.sub.3).sub.n where n is a number equal to from 0 to 0.34, and (1.2) a reaction product (R) of phosgene and a substnace (S) obtained from a substance of the formula Mg.sub.6 . Al.sub.2 . (OH).sub.16 . CO.sub.3 . (H.sub.2 O).sub.4 by calcination (heating), provided that (R) has a chlorine content of from 10 to 76% by weight and (U) has been obtained by milling (1.1) and (1.2) together.