摘要:
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.
摘要:
Copolymers of ethylene have from 1 to 30 mol % of alkyl(meth)acrylates and, if desired, other comonomers, and have a residual comonomer content of less than 0.5% by weight in the copolymer. A process for preparing copolymers of this type in a combination of stirred autoclave and tubular reactor is described, as is the use of the copolymers for preparing polyamide molding compositions.
摘要:
Emulsifiable ethylene polymers comprising copolymers of from 90 to 95% by weight of ethylene, from 4 to 10% by weight of one or more C3-C12 alkenecarboxylic acids, and from 0 to 1.2% by weight of one or more tertiary esters of the corresponding C3-C12 alkenecarboxylic acids, where the wax has a cinematic melt viscosity of from 800 to 3000 mm2/s, measured at 120° C.; and a process for preparing the novel emulsifiable ethylene polymers, emulsions comprising the novel ethylene polymers, a process for preparing the emulsions from the novel ethylene polymers, and also floor cleaners, car cleaners, leather cleaners and stone cleaners, and coatings for surfaces made from wood, metal, paper, glass or from plastics, comprising aqueous emulsions of the novel emulsifable waxes.
摘要:
A process for preparing ethylene polymers by the high-pressure method comprises dissolving one or more free-radical initiators in one or more ketones of the formula I where R1 and R2 are identical or different and are selected from among C1-C6-alkyl and C3-C12-cycloalkyl and R1 and R2 may also be covalently linked to one another to form a 4- to 13-membered ring, prior to the polymerization, compressing the solution, metering it into the polymerization reactor at one or more points and subsequently carrying out the polymerization at from 150 to 380° C. and from 500 to 4500 bar.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
In a process for the polymerization of ethylene and optionally further monomers in a high-pressure reactor at from 120 to 350° C. and pressures of from 1000 to 4000 bar, hydrogen is intermittently introduced into the reactor.
摘要:
Pigment concentrates comprising at least one pigment, a polyethylene wax prepared from one ethylene and, if desired, one comonomer using a metallocene catalyst, if desired a thermoplastic polymer and, if desired, additives can be used to color plastic moldings and plastic sheets.
摘要:
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.