Bayer Aktiengesellschaft

Mobay Corporation

Bayer Adtiengesellschaft

Helmut Woynar

Josef Pedain

Klaus Konig

Manfred Dietrich

Josef Sanders

Gundolf Jacobs

Torsten Heinemann

Mark R Kratz

Harro Traubel

Hans-Werner Muller

Uwe Scholz

Manfred Schmidt

William E Slack

Hans-Joachim Scholl

Jurgen Gronen

Hans J Focks

A process for the production of polyisocyanates having a biuret structure, comprising continuously combining organic diisocyanates having aromatically attached isocyanate groups in a mixing chamber with organic diamines having aromatically attached amino groups in a molar ratio of at least 8:1 to form a reaction mixture; and reacting said reaction mixture at a temperature of above 180.degree. C., wherein a residence time of said reaction mixture in the mixing chamber from when said organic diisocyanates and said organic diamines are combined is at most 60 seconds.

Process for the production of polyisocyanates having a biuret structure

A process is described for the preparation of stable, agglomerate-free, low-viscosity graft copolymer dispersions by the free-radical polymerization of olefinic monomers, such as styrene and/or acrylonitrile, with polyol compounds in the presence of a hydroxyl compound modified with castor oil. The use of these graft copolymer dispersions in the manufacture of polyurethane plastics, particularly flexible foams, by the isocyanate polyaddition process is also described.

Polymerizing monomers in presence of polyol and castor oil-polyol product

A continuous process for the preparation of highly stable, finely divided, low viscosity polymer polyols of small average particle size wherein in the first step an intermediate is prepared by reacting (1) a mixture of at least two ethylenically unsaturated monomers, preferably styrene and acrylonitrile, in a mixture comprising (2) a base polyol and (3) a macromer in the presence of (4) a free radical initiator, (5) a solvent having moderate chain transfer activity, and, optionally, (6) a reaction moderator at a temperature of at least 100.degree. C., such that the intermediate contains at least about 12% by weight of macromer, based on the weight of the base polyol and macromer, and a solids content of at least about 15% by weight and less than about 30% by weight, based on the weight of the base polyol, macromer and ethylenically unsaturated monomers. The intermediate, which functions as a seed for further polymerization, is then further reacted, in one or more stirred-tank reactors in series, in a mixture of at least two ethylenically unsaturated monomers, preferably styrene and acrylonitrile, in a base polyol and, optionally, a macromer, in the presence of solvent, initiator and a reaction moderator which are distributed among the remaining reactors.

Continuous process for the preparation of highly stable, finely divided,

Stable, agglomerate-free, low-viscosity graft copolymer dispersions are prepared by the radical polymerization of 25 to 65% by weight of ethylenically unsaturated monomers in the presence of a base polyol, a macromer, a low-molecular weight regulator and, optionally, an organic solvent. The dispersions of this process are suitable as a polyol component for the production of polyurethane plastics by the isocyanate addition process.

Low-viscosity, stable, agglomerate-free polymer polyols, a process for

A process for the production of stable, agglomerate-free, low viscosity graft copolymer dispersions through radical polymerization of ethylenically unsaturated monomers in the presence of a base polyol, a macromer, an enol ether of a specific formula, and optionally, an organic solvent. These enol ethers correspond to the general formula:

Low viscosity polymer polyols a process for their production as well as

Polyisocyanates with biuret structures are produced at temperatures above 250.degree. C. More specifically, an excess of a diisocyanate having aliphatically and/or cycloaliphatically bound isocyanate groups is reacted with a diamine containing aliphatically and/or cycloaliphatically bound amino groups at temperatures above 250.degree. C. for relatively brief periods of time. Water and/or polyvalent alcohols may optionally be included in the reaction mixture. The polyisocyanates with biuret structures produced by this process are characterized by good color, good dilutability with covalent solvents and comparatively low viscosity.

Process for the production of polyisocyanates with biuret structures

Leather treatment agents contain a mixture of

Leather treatment agent

Aqueous fatliquoring solutions, dispersions or emulsions are made with (a) polyethers having at least two hydroxyl groups and a molecular weight of from 200 to 20,000 and/or (b) polyester containing at least two hydroxyl groups and a molecular weight of from 200 to 20,000 and/or (c) polycarbonates containing at least two hydroxyl groups and a molecular weight of from 200 to 20,000 and/or mixtures thereof. These fatliquoring agents are used to treat tanned leathers until from 0.1 to 20 wt % has been taken up. The thus-treated leather is particularly useful in the production of leather-polyurethane compositions such as shoes without the use of an adhesive.

Fatliquoring solution dispersion or emulsion and a process for treating

The present invention relates to a process for the production of modified organic polyisocyanates containing urethane, carboxylic acid anhydride and biuret groups by reacting excess quantities of organic diisocyanates with a modifying agent containing

Process for the production of modified polyisocyanates, the compounds

The present invention is directed to a process for the production of polyisocyanates which have a biuret structure by reacting aliphatic diisocyanates with water at elevated temperature, characterized in that the reaction is carried out in the presence of:

Process for the production of polyisocyanates which have a biuret

The present invention relates to a process for the preparation of polyisocyanates which have a biuret structure of reacting excess quantities of aliphatic diisocyanates with biuretizing agents at elevated temperature, characterized in that the biuretizing agent contains

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Dormagen, Germany

Helmut Woynar