Abstract: Ethylene homopolymers and copolymers are prepared in a tube reactor at from 160° C. to 350° C. and pressures in the range from 500 to 5000 bar, with or without use of molar mass regulators, using a peroxide mixture comprising from 1 to 95 mol %, based on the total amount of the peroxide mixture, of at least one cyclic peroxide of the formula I, where the radicals R are identical or different and are selected from among alkyl groups and aryl groups, as polymerization initiator.

Abstract: Ethylene homopolymers and copolymers are prepared in a tube reactor at from 160° C. to 350° C.

Abstract: A process for coating a reactor, which comprises depositing a metal layer or a metal/polymer dispersion layer on the internal surface of the reactor in an electroless manner by bringing the surfaces into contact with a metal electrolyte solution which, besides the metal electrolyte, comprises a reducing agent and optionally a halogenated polymer to be deposited in dispersed form.

Abstract: A catalyst composition suitable for the (co)polymerization of alk-1-enes is obtainable by mixing a metallocene complex with a C3-C20-alk-1-ene in an inert solvent, reacting the resulting mixture in a controlled manner with a compound capable of forming metallocenium ions and diluting the resulting mixture with an inert nonpolar, essentially aliphatic solvent, and also, if desired, applying the catalyst composition to a particulate support material.

Abstract: A catalyst solution for polymerizing &agr;-olefins is obtainable by reacting a metallocene compound with an activator compound which can react with the metallocene compound so as to displace a ligand from the central atom and stabilize the resulting cationic complex by a non-coordinating anion as an ion pair, adding one or more &agr;-olefins in a molar ratio of metallocene compound: &agr;-olefins of from 1:1 und 1:100 and mixing with at least 10 parts by volume of an aliphatic hydrocarbon.

Abstract: Copolymer comprising ethylene units and vinyl formate units, the content of free vinyl formate in the polymer preferably being not more than 5000 ppm, based on the weight of the copolymer, a process for its preparation, and its use as flow improver, especially in petroleum distillates, preferably fuel and propellant compositions, especially petroleum middle distillates, and also a fuel and propellant composition comprising a principal quantity of a fuel and propellant and that quantity of a copolymer as above which is effective in improving the flow properties.

Abstract: Copolymer comprising ethylene units and vinyl formate units, the content of free vinyl formate in the polymer preferably being not more than 5000 ppm, based on the weight of the copolymer, a process for its preparation, and its use as flow improver, especially in petroleum distillates, preferably fuel and propellant compositions, especially petroleum middle distillates, and also a fuel and propellant composition comprising a principal quantity of a fuel and propellant and that quantity of a copolymer as above which is effective in improving the flow properties.

Abstract: In a process for preparing copolymers of ethylene with C.sub.3 -C.sub.10 -alk-1-enes, the polymerization is carried out at pressures in the range from 1000 to 3500 bar and at from 200 to 280.degree. C.

Abstract: A process for compressing ethylenically unsaturated monomers at a pressure of 200-5000 bar in the absence of a polymerization initiator comprises carrying out compression in the presence of a sterically hindered amine derivative.

Abstract: Copolymers of ethylene with .alpha.,.beta.-unsaturated carboxylic acids are prepared at from 50.degree. to 250.degree. C. and from 500 to 5000 bar in a stirred autoclave having a length/diameter ratio greater than 5:1 by a process in which the monomer mixtures are fed into the autoclave in at least two part-streams, the first part-stream being passed into the autoclave at the beginning of the autoclave pipe and the second part-stream being introduced at a position which is a distance away from the beginning which corresponds to 25-50% of the total length and the amount of the .alpha.,.beta.-unsaturated carboxylic acids in the first part-stream is from 20 to 90% less than the average amount in the further part-streams and a peroxide polymerization initiator having a lower decomposition temperature, or a mixture of peroxide polymerization initiators having a lower average decomposition temperature, than that of the initiators in the further part-streams is passed in with the first part-stream.

Abstract: A process for compressing ethylenically unsaturated monomers at a pressure of 200-5000 bar in the absence of a polymerization initiator comprises carrying out compression in the presence of a sterically hindered amine derivative.

Abstract: Fuel and lubricant compositions contain a poly-1-n-alkenylamine as an additive.

Abstract: Ethylene-based copolymers which are suitable as flow improvers for mineral oil middle distillates are composed ofa) from 50 to 94% by weight of ethylene,b) from 3 to 30% by weight of one or more vinyl esters of C.sub.2 -C.sub.6 -monocarboxylic acids,c) from 3 to 20% by weight of one or more aminoalkyl acrylates of the general formula I ##STR1## where R.sup.1 is hydrogen or methyl, R.sup.2 and R.sup.3 may be identical or different and are each hydrogen or C.sub.1 -C.sub.6 -alkyl and A.sup.1 is straight-chain or branched C.sub.2 -C.sub.10 -alkylene, andd) from 0 to 10% by weight of one or more monomers which are copolymerizable with the monomers a) to c),copolymers in which monomer b) is vinyl acetate and which have a number average molecular weight of from 5000 to 50,000 being excluded, or are composed ofa') from 50 to 95.5% by weight of ethylene,b') from 4 to 30% by weight of one or more vinyl esters of C.sub.2 -C.sub.6 -monocarboxylic acids,c') from 0.

Abstract: A process for the preparation of copolymers of ethylene and dicarboxylic acid in the presence of a free-radical inhibitor. The process comprises of warming a mixture of ethylene and C.sub.3 -C.sub.6 -alkenecarboxylic acid to a temperature of from 60.degree. to 100.degree. C. before addition of the free-radical inhibitor. The maximum polymerization temperature to recover said copolymers of ethylene is in the range of from 100.degree. to 260.degree. C.; and wherein said copolymer comprises from 94 to 99.5 mol % of ethylene and from 0.5 to 6.0 mol % of C.sub.3 -C.sub.6 -alkenecarboxylic acid.

Abstract: An ethylene-based copolymer which is suitable as a flow improver for mineral oil middle distillates and is composed ofa) from 50 to 94% by weight of ethylene;b) from 3 to 30% by weight of one or more vinyl esters of C.sub.2 -C.sub.6 -monocarboxylic acids;c) from 3 to 20% by weight of one or more aminoalkyl acrylates of the formula I ##STR1## which R.sup.1 is hydrogen or methyl, R.sup.2 and R.sup.3 are identical or different and are each hydrogen or C.sub.1 -C.sub.6 -alkyl and A.sup.1 is straight-chain or branched C.sub.2 -C.sub.10 -alkylene; andd) from 0 to 10% by weight of one or more monomers which are copolymerizable with the monomers a) to c), wherein copolymers containing vinyl acetate as monomer b) and having a number average molecular weight of from 5,000 to 50,000 are excluded from the scope of the copolymer.

Abstract: Polyolefins are thermomechanically degraded in a twin-screw extruder without a downstream degradation apparatus, at from 300.degree. to 550.degree. C. and from 1 to 100 bar and in average residence times of the reaction mixture of from 0.5 to 10 minutes, by a process in which the pressure in the twin-screw extruder is changed periodically or aperiodically with a fluctuation of from 0.5 to 30 bar. The novel process is particularly suitable for the degradation of polypropylene.

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: Carboxyl-containing copolymers of ethylene are prepared by polymer-analogous pyrolytic ester cleavage of copolymers consisting ofa) from 60 to 99.9 mol% of ethylene,b) from 0.1 to 40 mol% of C.sub.4 -C.sub.8 -tert-alkyl esters of copolymerizable C.sub.3 -C.sub.12 -carboxylic acids andc) from 0 to 20 mol% of further copolymerizable monomers by a method in which pyrolytic ester cleavage is carried out at from 150.degree. to 250.degree. C. in the presence of organic sulfonic acids, in the absence of a solvent and in the virtual absence of free radical initiators.

Abstract: A curable molding material comprises a coherent phase of a free-radical curable, unsaturated polyester resin in which finely particulate polyolefin particles are dispersed as disperse phase, the two phases being chemically bound to one another at the interfaces by ionic bonds.