Bayer Aktiengesellschaft

Bayer Materialscience Ag

Bayer Aktiengesesellschaft

Bayer Intellectual Property Gmbh

Michael Brockelt

Hartmut Knofel

Stefan Penninger

Herbert Stutz

Marcel Petinaux

Rudolf Uchdorf

Hans-Peter Schal

Gunter Hammen

Manfred Dietrich

Gerhard Wegener

Rolf William Albach

Jan Thomas Leu

Ralf Dohrn

Juan Cirujeda-Ranzenberger

Ludwig Deibele

Guido Naberfeld

Markus Hadley

Thomas Jan Leu

The invention provides a process for the purification of polymer polyols that ensures a reduction of acrylonitrile, styrene as well as the residual amounts of optionally used chain regulator, and of occurring recombination products of the initiator when azo initiators are used, to levels of &#x3c;25 ppm of acrylonitrile, &#x3c;50 ppm styrene, &#x3c;50 ppm chain regulator and &#x3c;280 ppm of recombination products by stripping using packed columns.

Process for stripping polymer polyols

The invention relates to flame resistant rigid foams and formulations useful for the production thereof. The polyol formulation must include at least one substance which is inert with respect to isocyanates, does not deplete the ozone layer and has a boiling point below 55&#xb0; C. and a reaction product of at least one compound with an aromatic ring, at least one aldehyde or ketone and at least one primary or secondary amine. This polyol formulation is reacted with an isocyanate, optionally with other commonly used additives, to produce rigid flame resistant foams.

Flame resistant rigid foams and formulations for the production thereof

The invention relates to a process for the fractionation and purification of aromatic polyamine mixtures and to the use thereof.

Fractionation and purification of aromatic polyamine mixtures and the

The invention relates to a process for the fractionation and purification of aromatic polyamine mixtures and the use thereof.

The invention relates to a process for the fractionation and purification of aromatic polyamine mixtures and their use.

The invention relates to a process for the fractionation and purification of aromatic polyamine mixtures and to their use.

The invention relates to a process for the fractionation and purification of mixtures of aromatic polyamines and to the use thereof.

Fractionation and purification of mixtures of aromatic polyamines and

Fractionation and purification of aromatic polyamine and the use thereof

The invention relates to an improved process for the production of polynuclear aromatic polyamines by condensation of aniline with formaldehyde in the presence of water and acidic catalysts and working up of the reaction mixture by extraction with a hydrophobic solvent, the acid catalyst accumulating in the aqueous phase of the extraction step being reused.

Process for the production of polynuclear aromatic polyamines

This invention relates to an improved process for the preparation of polynuclear aromatic polyamines in which the reaction product is prepared by condensing aniline with formaldehyde in the presence of water and acidic catalysts and is worked up by extraction with a hydrophobic solvent. The acid catalyst that accumulates in the aqueous phase during the extraction process is reused.

The present invention relates to an improved process for the preparation of multinuclear aromatic polyamines by the condensation of aniline with formaldehyde in the presence of water and acid catalysts and working up of the reaction mixture by extraction with a hydrophobic solvent. The acid catalyst obtained in the aqueous phase of extraction is reused.

Process for the preparation of multinuclear aromatic polyamines

Diisocyanates and isomer mixtures of diisocyanates corresponding to the formula ##STR1## in which R.sup.1, R.sup.2, m and n are as defined herein are produced by phosgenating diamines and isomer mixtures of diamines corresponding to the formula ##STR2## in which R.sup.1, R.sup.2, m and n are as defined herein. These diisocyanates which are liquid at room temperature and highly compatible with polyols are particularly useful in the production of polyurethanes.

Growing community of inventors

Leverkusen, Germany

Michael Brockelt