Abstract: In a process for preparing polyethylene in tube reactors with or without autoclaves, where a free-radical initiator is introduced with or without cold ethylene into a flowing ethylene- and comonomer-containing medium, rotation is generated between two streams (61, 62) to be mixed at an angle (66) or by provision of a swirl element (20, 80) in the flow cross section (27, 28). In the region of a feed point (72, 81) for a free-radical initiator, there is provided a cross-sectional constriction (63, 67, 71) at which the free-radical initiator is introduced through an optimized off-center outlet opening (44) of an introduction finger (40) into the rotating flow (61, 62, 70).

Abstract: In a process for polymerizing ethylene and, if desired, further monomers in a high-pressure reactor at from 140 to 320° C. and pressures of from 1000 to 4000 bar, but in any case under pressure and temperature conditions under which water displays supercritical behavior, water is introduced continuously or intermittently into the reactor.

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: The invention relates to a method for the continuous production of ethylene homo- and ethylene co-polymers in the presence of radical polymerisation initiators and, optionally, molecular weight regulators in a tubular reactor with a hot water jacket and one or several reaction zones at pressures of 1000 to 4000 bar and temperatures of 120° C. to 350° C. The hot water jacket of each reaction zone is divided into two independently-controllable, separate, longitudinal sections and the water exit temperature from the tubular jacket of the first longitudinal section per reaction zone, extending between the point of initiator addition and 20 to 50% of the reaction zone length, is set to 180° C. to 210° C. and in the following second longitudinal section of said reaction zone the hot water exit temperature from the tube jacket is set to 140° C. to 180° C.

Abstract: In a process for preparing polyethylene in tube reactors with or without autoclaves, where a free-radical initiator is introduced with or without cold ethylene into a flowing ethylene- and comonomer-containing medium, rotation is generated between two streams (61, 62) to be mixed at an angle (66) or by provision of a swirl element (20, 80) in the flow cross section (27, 28). In the region of a feed point (72, 81) for a free-radical initiator, there is provided a cross-sectional constriction (63, 67, 71) at which the free-radical initiator is introduced through an optimized off-center outlet opening (44) of an introduction finger (40) into the rotating flow (61, 62, 70).

Abstract: The invention relates to a method for the continuous production of ethylene homo- and ethylene co-polymers in the presence of radical polymerisation initiators and, optionally, molecular weight regulators in a tubular reactor with a hot water jacket and one or several reaction zones at pressures of 1000 to 4000 bar and temperatures of 120° C. to 350° C. The hot water jacket of each reaction zone is divided into two independently-controllable, separate, longitudinal sections and the water exit temperature from the tubular jacket of the first longitudinal section per reaction zone, extending between the point of initiator addition and 20 to 50% of the reaction zone length, is set to 180° C. to 210° C. and in the following second longitudinal section of said reaction zone the hot water exit temperature from the tube jacket is set to 140° C. to 180° C.

Abstract: In a process for polymerizing ethylene and, if desired, further monomers in a high-pressure reactor at from 140 to 320° C. and pressures of from 1000 to 4000 bar, but in any case under pressure and temperature conditions under which water displays supercritical behavior, water is introduced continuously or intermittently into the reactor.

Abstract: In a process for the polymerization or copolymerization of ethylenically unsaturated monomers in the presence of polymerization initiators which decompose to form free radicals in a continuously operated polymerization apparatus comprising a fresh gas feed line, a precompressor, a postcompressor, a reactor, a pressure maintenance valve, a high-pressure circuit having a high-pressure product separator and a high-pressure circulation gas return line, a product valve and a low-pressure circuit having a low-pressure product separator and a low-pressure circulation gas return line, nitrogen monoxide or oxygen is introduced as inhibitor into the high-pressure circuit, into the low-pressure circuit and/or the precompressor.

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: The invention relates to a method for polymerizing or copolymerizing ethylenically unsaturated monomers in the presence of radically decomposing polymerization initiators in a continuously operating polymerization device. Said polymerization device is composed of a fresh gas supply, a pre-compressor, a post-compressor, a reactor, a pressure maintaining valve, of a high-pressure circuit, which is provided with a high-pressure product separator and with a high-pressure circuit gas return, and of a product valve and a low-pressure circuit, which is provided with a low-pressure product separator and with a low-pressure circuit gas return. The inventive method is characterized in that nitrogen monoxide or oxygen is added in a dosed manner as an inhibitor into the high-pressure circuit, into the low-pressure circuit and/or into the pre-compressor.

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: A relief printing plate whose photopolymerized relief layer has a non-tacky surface is produced by (1) imagewise exposure of a photopolymerizable relief-forming recording layer which contains one or more polymeric binders containing acid groups, (2) washing out (development) of the unexposed and therefore non-photopolymerized parts of the imagewise exposed relief-forming recording layer with a developer and (3) aftertreatment of the resulting photopolymerized relief layer with a basic aftertreatment solution.

Abstract: In a photosensitive recording element which contains at least one photopolymerizable recording layer (B) consisting ofb.sub.1) at least one partially of virtually completely hydrolyzed poly(vinyl alkanecarboxylate) and/or at least one partially or virtually completely hydrolyzed vinyl alkanecarboxylate/alkylene oxide graft copolymer as a binder,b.sub.2) at least one photopolymerization initiator,b.sub.3) at least one photopolymerizable olefinically unsaturated compound (monomer) which is compatible with the binder (b.sub.1), and/or photopolymerizable olefinically unsaturated radicals which are bonded as side radicals and/or terminal radicals to the binder (b.sub.1), andb.sub.4) at least two assistants, at least one of the said assistants (b.sub.4) has been selected from the group consisting ofb.sub.41) the isoalloxazines and the alloxazines, and at least one of the other assistants has been selected from the group consisting ofb.sub.

Abstract: A photosensitive recording material contains a mixture of carboxyl-containing polymers having ethylenically unsaturated side groups, one or more ethylenically unsaturated monomeric compounds, a photoinitiator and a .beta.-aminoalcohol.It is suitable for the production of printing plates.

Abstract: A novel light-sensitive recording element for preparing relief plates or relief printing plates comprises a dimensionally stable base and at least one photopolymerizable recording layer (A) consisting essentially of at least one polymer as binder, at least one photopolymerization initiator, at least one photopolymerizable olefinically unsaturated compound (monomer) which is compatible with the polymeric binder, and/or photopolymerizable olefinically unsaturated radicals which are linked internally and/or terminally to the polymeric binder, and at least one additive, the said additive or at least one of the said additives being selected from the group consisting of the lecithins of the general formulae I and II ##STR1## where R.sup.1 and R.sup.2, which may be identical to or different from each other, are each C.sub.11 -C.sub.18 -alkyl or C.sub.11 -C.sub.18 -alkenyl, with the proviso that at least one of R.sub.1 and R.sub.2 is C.sub.11 -C.sub.

Abstract: Photopolymerizable laminates suitable for producing flexible and resilient printing plates carry on a dimensionally stable base at least one intermediate layer and on top thereof a photopolymerizable layer which consists essentially of a mixture of a water-soluble copolymer or derivative of polyvinyl alcohol, a specific copolymerizable mono-functional (meth)acrylate, a photoinitiator and a thermal polymerization inhibitor.

Abstract: Photopolymerizable laminates suitable for producing printing plates have on a dimensionally stable base at least one intermediate layer and on top thereof a photopolymerizable relief-forming layer, the intermediate layer containing aryl glycidyl (meth)acrylate in an at least partially polymerized state.