Abstract: 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 <25 ppm of acrylonitrile, <50 ppm styrene, <50 ppm chain regulator and <280 ppm of recombination products by stripping using packed columns.

Abstract: The invention relates to a process for the purification of polymer polyols by stripping using packed columns.

Abstract: 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° 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.

Abstract: 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° 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.

Abstract: The present invention relates to finely dispersed, low-viscosity polymer polyols which are stabilized in a novel manner and which are characterized by a high content of polystyrene or polystyrene copolymers. This invention also relates to the preparation of such polymer polyols, and their use for the preparation of polyurethane materials.

Abstract: The present invention provides an improved process for the continuous filtration of filled polyols containing deformable solid particles, wherein filtration of the filled polyols is performed with dynamic pressure disc filters.

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

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

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

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

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

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

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

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

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A diisocyanate corresponding to the formula ##STR1## in which R.sup.1, R.sup.2, R.sup.3, m and n are as defined herein is prepared by phosgenating a diamine corresponding to the formula ##STR2## in which R.sup.1, R.sup.2, R.sup.3, m and n are as defined herein. The diisocyanate may contain C.sub.1 -C.sub.12 -monoalkyl-substituted methylene-bis-(cyclohexylisocyanate)isomers in an amount of up to 40 wt. %. These new diisocyanates which are liquid at room temperature and compatible with polyols are particularly useful in the production of polyurethanes.