Basf Aktiengesellschaft

Richard Thoma

Hermann Fischer

Axel Sanner

Peter Horn

Hugo Fuchs

Gunter Pipper

Hans-Uwe Schenck

Eugen Gehrer

John-Bryan Speakman

Rainer Theysohn

Otto-Alfred Grosskinsky

Franz Schmidt

Paul Matthies

Eduard Heil

Joachim Stedefeder

Hanshelmut Kaeppel

Siegfried Riegger

Giorgio Greening

Ernst Kochendoerfer

Bernd Kast

Werner Lagaly

Mixtures which contain silver with a particle diameter of from 0.001 to 5 .mu.m on a neutral or basic non-zeolite carrier oxide of elements of group IIa, IIIa, IIb, IIIb of the Periodic Table of the Elements, of the lanthanides or mixtures thereof, and a process for preparing these mixtures and antibiotic compositions which comprise these mixtures are described.

Mixtures containing fine metallic silver particles on a neutral to basic

Nylons are prepared by a continuous process in which, in a precondensation zone, an aqueous solution of a salt of a dicarboxylic acid of 6 to 18 carbon atoms and a diamine of 6 to 18 carbon atoms is heated to 250.degree.-300.degree. C. under superatmospheric pressure, with simultaneous vaporization of water and formation of a prepolymer, the prepolymer and the vapor are separated, and the former is fed into a polycondensation zone and condensed under superatmospheric pressure of from 1 to 10 bar and at from 250.degree. to 300.degree. C., wherein the aqueous salt solution is condensed under superatomspheric pressure of from 1 to 10 bar in the first third of the tubular precondensation zone provided with baffles, until the degree of conversion is not less than 93%, and the prepolymer and the vapor phase are brought into intimate contact with one another in the remaining two thirds of the precondensation zone.

Continuous preparation of nylon from aqueous salt solution in

A process for the continuous preparation of .epsilon.-caprolactam by Beckmann rearrangement of cyclohexanone-oxime, dissolved in a solvent which is inert toward oleum and is immiscible with oleum and water, at an elevated temperature, with removal of the heat of rearrangement by evaporation of the solvent, wherein oleum containing caprolactam is circulated successively through a conveying zone, a mixing zone, a boiling zone and a separating zone, upstream of the conveying zone oleum is added at the rate at which it is consumed, in the mixing zone cyclohexanone-oxime dissolved in solvent is added under turbulent conditions, in the boiling zone the heat of rearrangement is removed in a conventional manner by evaporating the solvent and recycling the condensate, and in the separating zone the reaction mixture is separated into a solvent phase, from which solvent is withdrawn at the rate at which the phase is formed, and a caprolactam-containing oleum phase, which is removed at the rate at which it is formed.

Continuous preparation of .epsilon.-caprolactam by Beckmann rearrangement

An economical and environmentally advantageous process for the continuous manufacture of unsaturated polyesters, wherein the vapors formed during the polycondensation are purified, in a two-part distillation column, to a degree where the residual content of organic starting materials is less than 1.5 percent by weight, based on the total weight of the effluent, and the unconverted starting materials are recycled to the process.

Continuous manufacture of unsaturated polyesters

Polymers in powder form are manufactured by polymerizing water-soluble ethylenically unsaturated monomers, which form hydrophilic polymers, in a powder bed of polymers of water-soluble ethylenically unsaturated compounds in the presence of polymerization initiators and water as an auxiliary liquid, the water being entirely or partially removed from the polymerization zone by evaporation during the polymerization.

Process for preparing polymers in powder form

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Battenberg, Germany

Richard Thoma