Bayer Aktiengesellschaft

Miles Inc.

Christian Konig

Pramod Gupta

Herbert Gebauer

Wilfried Nolte

Hans-Wilhelm Engels

Klaus Biskup

Manfred L Gallus

Uwe J Zarnack

Rudolf Uchdorf

Chiraranjan Podder

Eckart Waldau

Dieter Becher

Wilhelm Hagen

Franz-Moritz Richter

Eckhard Tiemann

Hans Czwalinna

Hans-Jurgen Rabe

Volker Weintritt

Reinhold Wullner

William C Forester

Polyaromatic polyisocyanates are modified by reaction with 0.1 to 10 weight %, preferably 2 to 7 weight % (based on polyisocyanate) of a polyether alcohol of molecular weight 206 to 948, obtainable by the reaction of alkylene oxides with C.sub.6 -C.sub.30, preferably C.sub.8 -C.sub.20, hydrocarbons containing 1 to 3 active H atoms, and are used for the production of rigid polyurethane foamed materials.

Modified aromatic polyisocyanates and their use for the production of

A continuous process for the preparation of aromatic diisocyanates by phosgenation of the corresponding diamines, in which the reaction is carried out in the gas phase. The mean contact time for the gaseous reactants is from 0.5 to 5 seconds with a mean deviation of no more than 6%. The product diisocyanate is obtained in yields of over 95%.

Process for the preparation of aromatic diisocyanates

A process for recovering a distillate of tolylene diisocyanate and an isocyanate-group-containing sump product containing less than 200 ppm (by weight) tolylene diisocyanate from A) distillation residues obtained in the production of tolylene diisocyanate by mixing of the distillation residues A) with B) optionally urethane- and/or allophanate-modified polyisocyanates or polyisocyanate mixtures of the diphenyl methane series, heating of the mixture to 190.degree. to 250.degree. C. and simultaneously or subsequently working up by distillation.

Process for recovering polysocyanates from the distillation residues

A process for production of polyamines of the diphenylmethane series through a condensation reaction of aniline with formaldehyde in the presence of an acid catalyst, neutralization of the acid catalyst after reaction completion, and distillation of the resultant polyamine mixture is described. The key feature of the process is the abrupt increase in reaction temperature after the condensation reaction or after the first rearrangement step.

Process for the production of polyamine mixtures of the

The present invention relates to the use of nucleus-substituted 4-hydroxyphenyl propionic acid compounds for stabilizing organic polyisocyanates.

Stabilization of organic polyisocyanates

Carbon monoxide is produced in an improved process in a carbon-filled, water-cooled generator in the configuration of a truncated cone in the longitudinal section, by the gasification of said carbon with a mixed gas of oxygen and carbon dioxide, wherein the improvement comprises injecting the mixed gas into the generator through at least one downwardly-directed, coolable nozzle arranged in the generator sidewall and removing the carbon monoxide formed.

Process for the production of carbon monoxide

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Kaarst, Germany

Christian Konig