Basf Aktiengesellschaft

Rudolph Hans Gath

Hugo Fuchs

Klaus Kartte

Uwe Brand

Ruediger Schmitz

Hans-Joachim Weis

Kurt Kahr

Dieter Lummel

Klaus-Dieter Grammatik

A method for the continuous monitoring of the coating of a yarnlike dielectric material with assistants comprises applying a solution of said assistants dissolved in a polar solvent to said yarnlike material, then passing said yarnlike material between the electrodes of a downline capacitive measuring element, determining the capacity changes of said downline capacitive measuring element, and using said capacity changes to calculate the unevenness of the layer thickness of the applied solution.

Continuous monitoring of the coating of a filamentary dielectric material with assistants

A method of simultaneously purifying crude caprolactams obtained from the Beckmann rearrangement of cyclohexanone oxime in oleum and the gas-phase rearrangement of cyclohexanone oxime in the presence of catalysts. The improvement consists in that the crude caprolactam obtained from the catalytic gas-phase rearrangement is added to the acid rearrangement mixture derived from the Beckmann rearrangement in oleum and the mixture is maintained at temperatures of from 100.degree. to 200.degree. C with thorough mixing, whereupon it is neutralized and worked up. Advantageously, the content of lactam in the catalytic gas-phase rearrangement is from 5 to 30% of the content of lactam in the acid rearrangement mixture obtained from the Beckmann rearrangement.

Method of purifying caprolactam

A process for processing polycaprolactam extraction liquors by evaporation of water and distillation of the residue in which the evaporation of water is carried out in a plurality of stages and the evaporation energy for the removal of the bulk of the water is taken from the heat liberated in the rearrangement of cyclohexanone oxime to caprolactam in oleum or sulfuric acid by using the extraction water for cooling the rearrangement mixture and utilizing the heat absorbed by the extraction water for the concentration of this extraction water by evaporation of water.

Processing polycaprolactam extraction liquors

A process for the partial dehydration of cyclohexanone oxime by treatment with aqueous solutions of inorganic salts, wherein the crude cyclohexanone oxime is extracted, above its melting point, with a concentrated ammonium salt solution and/or hydroxylammonium salt solution in countercurrent in an extraction column and the salt solution is then separated from the partly dehydrated cyclohexanone oxime, reconcentrated by evaporation and recycled to the oxime dehydration process. The cyclohexanone oxime melt which has been dehydrated to water contents of about 4 to 6% by weight is treated with a heated inert gas above its melting point and the off-gas is washed to remove entrained cyclohexanone oxime.

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Mannheim, Germany

Rudolph Hans Gath