Abstract: Disclosed is a process for pressurizing ethylenically unsaturated monomers to 200-5000 bar in the absence of a polymerization initiator, which comprises effecting said pressurizing in the presence of nitroxyl compounds of the formula I where R1 and R2 are singly C1-C4-alkyl or combine with the joining carbon atom to form a 5- or 6-membered saturated hydrocarbon ring, R3 is C1-C4-alkyl, and R4 is hydrogen or C1-C12-alkyl. Also disclosed are a process for preparing copolymers by such pressurization and subsequent polymerization and copolymers obtainable thereby.

Abstract: Oxidized waxes are obtainable by oxidation of polyolefins obtainable by means of metallocene catalysis and having a molecular weight Mw in the range from 1000 to 40,000 g/mol.

Abstract: In a process for the high-pressure polymerization of ethylene in a high-pressure autoclave or in a high-pressure tube reactor having one or more metering points for one or more peroxides, no peroxide or a reduced amount of peroxide is metered in during the time interval in which the pressure is lowered by opening a pressure maintenance valve and the original amount of peroxide per unit time is metered in again as soon as the pressure after closure of the pressure maintenance valve has built up again so that it exceeds 90% of the pressure difference between nominal pressure and lowered pressure.

Abstract: In a process for preparing polyethylene waxes at from 200 to 350° C.

Abstract: A process is described for copolymerizing ethylene with vinyl esters and, if desired, with further vinylic comonomers in a tube reactor at pressures of from 500 to 4000 bar and at not more than 220° C., which comprises initiating the free-radical polymerization at at least two locations of the tube reactor by adding a catalyst/initiator and adjusting the temperature profile within the reactor such that the temperature maxima downstream of the initiation locations are from 150 to 220° C. and differ by less than ±10° C. from one another.

Abstract: Emulsifiable ethylene polymers comprising copolymers of

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: A process for preparing oxidized polyolefin waxes by reacting polyolefin waxes with oxygen or oxygen-containing gases at from 140 to 200° C. and at pressures of from 5 to 200 bar involves conducting the oxidation reaction continuously in a tube reactor but excludes the reaction of polyolefins prepared by metallocene catalysis.

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: Polymers essentially comprising units of the formula I ##STR1## in which R.sup.1 and R.sup.2 are hydrogen or methyl andR.sup.3 is hydrogen, C.sub.1 -C.sub.18 -alkyl, C.sub.5 -C.sub.12 -cycloalkyl, C.sub.6 -C.sub.10 -aryl or C.sub.6 -C.sub.10 -aryl-C.sub.1 -C.sub.4 -alkyl, it being possible for these radicals, with the exception of the C.sub.1 -C.sub.18 -alkyl radicals, to be up to trisubstituted by radicals selected from the group consisting of C.sub.1 -C.sub.4 -alkyl, C.sub.1 -C.sub.4 -alkoxy and halogen, are prepared by reacting a polymer based on C.sub.1 -C.sub.20 -alkyl esters of acrylic acid, methacrylic acid or mixtures thereof with ammonia or a primary amine in an extruder, by mixing the ammonia or the primary amine by mixing intensively with a melt of the polymer to be reacted, at at most 250.degree. C., before the imidation is carried out, and are used for producing thermoplastic moldings, films or fibers.

Abstract: A process is described for preparing oxidized polyethylene waxes by oxidizing such waxes with oxygen or oxygen-containing gases at from 120 to 250.degree. C. under a pressure of from 1 to 200 bar, which involves conducting the oxidation reaction in the presence of an ethylene-(meth)acrylic acid copolymer.

Abstract: Transparent molded articles having a high-contrast laser inscription thereon are produced from a polymer mixture consisting ofA) from 40 to 99% by weight of a polymer of an alkyl ester of (meth)acrylic acid,B) from 1 to 50% by weight of a copolymer of styrene and acrylonitrile having an acrylonitrile content of from 8 to 30% by weight,C) from 0 to 50% by weight of rubber particles, andD) from 0 to 20% by weight of additives and processing auxiliaries, by preparing a transparent molded article from the polymer mixture, and exposing the transparent molded article to laser radiation.

Abstract: A description is given of tetramethylpiperidine-containing copolymers comprising 1-100 mol % of identical or different monomer units of the general formula I ##STR1## (R.sup.1 =COOR.sup.7, COR.sup.8, CONR.sup.8 R.sup.9, CN; R.sup.2 =H, C.sub.1 -C.sub.12 -alkyl, COOR.sup.7, COR.sup.8, CONR.sup.8 R.sup.9, CN; R.sup.3 =H, methyl, ethyl, propyl; R.sup.6 =H, C.sub.1 -C.sub.8 -alkyl; R.sup.7 =H, C.sub.1 -C.sub.8 -alkyl, C.sub.5 -C.sub.8 -cycloalkyl, C.sub.3 -C.sub.5 -alkenyl, substituted or unsubstituted phenyl; R.sup.8 and R.sup.9 =H, C.sub.1 -C.sub.12 -alkyl, C.sub.5 -C.sub.8 -cycloalkyl, substituted or unsubstituted phenyl; X=oxygen, sulfur, NR.sup.6) and also other monomers, and also of processes for preparing the copolymers, of the use of the copolymers as stabilizers, including light stabilizers, and of organic material comprising the copolymers.

Abstract: A process for preparing keto-functional polyethylene waxes having a molecular weight of from 150 to 1000 g/mol by telomerization of ethylene with aldehydes at from 500 to 5000 bar and from 100 to 280.degree. C., wherein ethylene and aldehyde are employed in a molar ration of from 5:1 to 50:1.

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: Essentially dry materials are obtained by mechanically dewatering water-moist rubber, prepared by emulsion polymerization and precipitation, to give a compact material having a rubber content of at least 50%, by a process in which the previously dewatered rubber is fed to the feed section of a twin-screw extruder which has screws rotating in the same direction and possesses, in succession in the conveying direction, at least two back-up zones and two associated dewatering orifices, each of which may be provided with a retaining screw, and at least one kneading zone, one devolatilization zone and finally one discharge zone, which may be closed by a die lip, and the water separated off is discharged at the dewatering orifices in liquid form.

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: Fluorescent pigments contain essentially a polymer matrix based on polymethyl methacrylate and a nonpolar fluorescent dye from the coumarin or perylene series, the polymer matrix being a crosslinked polymethacrylate or polyacrylate prepared by suspension polymerization.