Basf Aktiengesellschaft

Basf Se Corporation

Basfaktiengesellschaft

Michael Reichelt

Peter Falke

Regina Hendreich

Udo Rotermund

Peter Von Malotki

Holger Seifert

Werner Hinz

Renate Hempel

Uwe Keppeler

Werner Wiegmann

Johannes Buettner

Stefan Dinsch

Holger Allardt

Gottfried Knorr

Reiner Reetz

Marion Heinz

J&uuml;rgen Winkler

Anja Biedermann

Gerd H&ouml;ppner

Reinhard Tonder

Johannes Büttner

The invention provides a process for removing nitrocresols from wastewater of mononitrotoluene preparation, which comprises acidifying the alkaline wastewater of mononitrotoluene preparation with acids to a pH of at most 3 and treating the nitrocresols with an extractant. The invention further provides the preparation of dinitrotoluene by use of the nitrocresol-containing extracts as a feedstock.

Method for extracting nitrocresols from waste water produced in the manufacture of mononitrotoluene and use of said extract

Polyetherols based on solid initiator substances and liquid, hydroxyl-containing coinitiators are prepared by a catalyzed addition reaction of alkylene oxides by a process in which the initiator combination contains diols carrying ethoxy structures, the ratio of the average number of hydroxyl groups per mole of initiator combination to the number of ethoxy structures in the polyetherol being from 1:0.2 to 1:1.8 and the ratio of the amounts by weight of the diols carrying ethoxy structures to the average molecular weight of the polyetherol being from 1:2 to 1:15. The polyetherols prepared by this process are used for the preparation of PUR, in particular, rigid PUR foams.

Preparation of polyetherols

Prepolymers which contain isocyanate groups, have an NCO content of at least 30.0% by weight and can be prepared by reacting an isocyanate mixture consisting predominantly of diphenylmethane diisocyanates and polyphenylpolymethylene polyisocyanates and having a proportion of two-ring isomers of not more than 74% by weight with at least 4-functional polyols or a mixture of polyols having a mean functionality of at least 4, where the polyols or polyol mixtures have a hydroxyl number of from 200 to 1650 mg KOH/g and a number average molecular weight of less than 1100 g/mol. The present invention also provides a process for preparing these prepolymers containing isocyanate groups, provides for their use for producing polyurethanes and provides a process for producing polyurethanes by reacting at least one novel prepolymer containing isocyanate groups, if desired in admixture with further organic and/or modified organic isocyanates (a), with compounds having at least two reactive hydrogen atoms (b) in the presence of, if desired, blowing agents (c), catalysts (d) and, if desired, further auxiliaries and/or additives (e).

Prepolymers containing isocyanate groups and a method for the production thereof

A stable dispersion of melamine in polyol components comprising at least one relatively high molecular weight compound containing at least two reactive hydrogen atoms and, if desired, low molecular weight chain extenders and/or crosslinkers, blowing agents, catalysts, flame retardants and also further auxiliaries and/or additives is prepared by using the melamine in combination with at least one amine and at least one organic and/or modified organic isocyanate. Such a dispersion can be used for producing flame-resistant polyurethane foams.

Preparation of a stable dispersion of melamine in polyol components

A stable dispersion of melamine in polyol components comprising at least one relatively high molecular weight compound containing at least two reactive hydrogen atoms and, if desired, low molecular weight chain extenders and/or crosslinkers, blowing agents, catalysts, flame retardants and also further auxiliaries and/or additives is prepared by using the melamine in combination with at least one amine and at least one organic and/or modified organic isocyanate. Such a dispersion can be used for producing flame-resistant polyurethane foams

The flameproofed, rigid, isocyanate-based foams, in particular rigid polyurethane and polyisocyanurate foams, are produced by reacting

Production of flameproofed, rigid, isocyanate-based foams

In a process for producing open-celled rigid foams by reacting a) polyisocyanates with b) compounds containing hydrogen atoms which are reactive toward isocyanates, in the presence of c) water, d) if desired, organic compounds acting as physical blowing agents, e) catalysts, auxiliaries and/or additives, the compounds containing reactive hydrogen atoms used are substances having the structure I: ##STR1## where m is 0-15

Open-celled rigid foams based on isocyanate

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Ruhland, Germany

Michael Reichelt