Covestro Deutschland Ag

Bayer Materialscience Ag

Bayer Intellectual Property Gmbh

Covestro Intellectual Property Gmbh & Co. Kg

Tim Loddenkemper

Friedhelm Steffens

Rainer Bruns

Dietmar Wastian

Joachim Zechlin

Stefan Wershofen

Wolfgang Lorenz

Andreas Karl Rausch

Reinhard Halpaap

Frank Richter

Josef Sanders

Michael Schelhaas

Georg Ronge

Oswald Wilmes

Andreas Hecking

Jan Busch

Kai Verkerk

Frank Gerhartz

Wilfried Pinke

Stefan Groth

Katrin Joschek

Walther Müller

Timm Schmidt

Michael Merkel

Rainer Bellinghausen

Markus Dugal

Jürgen Arras

Michel Haas

Hartwig Kempkes

Andre Rittermeier

Thomas Bludowsky

Bernd Rüffer

Thomas Burbach

Kartin Joschek

Michael Venz

Stefan Hirschfeld

Michel DrDr Haas

The present invention relates to a process for preparing an isocyanate comprising the steps of (A) reacting an amine with a stoichiometric excess of phosgene using an aromatic solvent of formula CHCl, wherein X=1 or 2, (a) as a diluent during the reaction and/or (b) as a means for cooling the reaction mixture formed from the reaction of the amine with phosgene (so-called quench) to obtain (optionally after a decompression) a liquid product mixture comprising the isocyanate and the aromatic solvent employed and a gaseous product mixture containing phosgene and hydrogen chloride; followed by (B) isolating the isocyanate from the liquid product mixture obtained in step (A) comprising the step of a final distillation in which the isolated isocyanate is obtained as a product stream, wherein in the final distillation or in a distillation step upstream of the final distillation at least one stream comprising aromatic solvent of formula CHCl, wherein Y=X+1, is (at intervals or continuously) discharged such that the isolated isocyanate has a mass fraction, based on its total mass, of aromatic solvent of formula CHClin the range from 0.0 ppm to 9.9 ppm, preferably 0.0 ppm to 5.0 ppm, particularly preferably 0.0 ppm to 3.0 ppm.

Method for producing isocyanates

The invention relates to a method for preparing a suspension of a hydrochloride of an organic amine, comprising the following steps of (i) initially charging at least one organic solvent in a reaction vessel to form a liquid level, (ii) adding hydrogen chloride, (iii) adding the organic amine, wherein the organic amine is added below the liquid level present in the reaction vessel and steps (ii) and (iii) are at least partly carried out simultaneously. Furthermore, the present invention also relates to a method wherein the suspension obtained after step (iii) is reacted in a step (iv) with phosgene to obtain the organic isocyanate corresponding to the organic amine used, to the corresponding organic isocyanate and to the use of the organic isocyanate for producing polyisocyanates.

Method for preparing an amine hydrochloride suspension

A process for regenerating a catalyst containing ruthenium or ruthenium compounds, which includes, optionally at elevated temperature, subjecting the catalyst to a hydrogen halide treatment, particularly a gas stream comprising hydrogen chloride, under non-oxidative conditions and, optionally at reduced temperature, to at least a two-stage oxidative post-treatment. The catalyst may have been poisoned by sulfur compounds. After the removal of sulfur, the catalyst is subjected to an oxidative post-treatment.

Method for regenerating a toxified catalyst containing ruthenium or ruthenium compounds

The industrial scale preparation of isocyanates gives rise to distillation bottom streams that are in need of further workup. These distillation bottom streams still also contain, as well as a distillation residue consisting of compounds that can be evaporated without decomposition only with great difficulty if at all (also referred to as residue for short), proportions of the desired target product (i.e. isocyanate to be prepared). The present invention relates to a process that enables recovery, in an efficient manner, of this proportion of isocyanate to be prepared in a distillation bottom stream which is obtained in the workup of the crude liquid process product which contains the isocyanate to be prepared and is formed in an isocyanate preparation process. More particularly, the present invention relates to a drying step in which the isocyanate to be prepared is recovered to form a solid material that has been largely to completely freed of this isocyanate. This drying step is characterized by a minimum content of compounds containing carbodiimide groups of 15% by mass, preferably 20% by mass, more preferably 30% by mass, based on the total mass of the distillation residue fed to the drying apparatus used, where this minimum content can also be adjusted by an in situ carbodiimidization.

Process for preparing an isocyanate

The invention relates to a novel method for producing polyisocyanurates comprising isocyanate groups, based on 2,4- and 2,6-toluylene diisocyanate (TDI) and to the use thereof in coating compositions.

Method for producing TDI-trimerisates with high purity

The invention relates to the production of isocyanates by means of phosgenation of the corresponding primary amines in the gas phase, wherein the reactant flows of amine and phosgene are fed separately to a reactor through a pre-heated inert gas flow. Isocyanates within the sense of the invention are, in the broadest sense, all isocyanates whose corresponding amines can be substantially converted into the gas phase without decomposing, with the exception of 1,5-pentane diisocyanate.

The invention relates to polyisocyanates comprising urethane groups, based on toluylene diisocyanate, to a method for their production, and to their use as the polyisocyanate component in one- and two-component polyurethane coatings.

Method for producing light-coloured TDI-polyisocyanates

The invention relates to a method for preparing isocyanates by phosgenating the corresponding amines, wherein low-boiling secondary components, excess phosgene, and the co-product hydrogen chloride are separated from the crude liquid isocyanate stream, which is obtained after the phosgenation has occurred, within a maximum of 60 minutes, and wherein the crude liquid isocyanate stream is not exposed to temperatures above 250&#xb0; C. until said separation.

The invention relates to a process for the preparation of isocyanates by reaction of the corresponding amines with phosgene in the gas phase, wherein a diluent containing between 90.0000% by weight and 99.9999% by weight of substances which are inert in the phosgenation process and between 0.0001% by weight and 10.0000% by weight of oxygen is present during the conversion of the amine into the gas phase and the molar ratio of amine to oxygen (O) is &#x2267;1,000:1.

Method for producing isocyanates in the gas phase

Chlorine is prepared by catalytic oxidation of a hydrogen chloride stream having a content of sulfur in elemental or bonded form of less than 100 ppm, preferably less than 50 ppm, more preferably less than 5 ppm, most preferably less than 1 ppm, based on the weight of the hydrogen chloride stream.

Process for the oxidation of a gas mixture containing hydrogen chloride

The present invention relates to a method for working up distillation, residues from isocyanate production in which monomeric isocyanate present in distillation residues is recovered by means of a spray-dry method and the overall yield of monomeric isocyanate is thus significantly increased.

Method for working up distillation residues from isocyanate production

Processes comprising: providing a catalyst comprising a catalytic component selected from the group consisting of ruthenium, ruthenium compounds, and combinations thereof, wherein the catalyst is sulfur-poisoned with one or more sulfur compounds; and treating the catalyst with a gas stream comprising a hydrogen halide under nonoxidative conditions such that the catalyst is regenerated.

Processes for regenerating sulfur-poisoned, ruthenium and/or ruthenium compound-containing catalysts

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Dormagen, Germany

Tim Loddenkemper