Mobay Corporation

Miles Inc.

Bayer Aktiengesellschaft

Mobay Chemical Corporation

Kenneth L Dunlap

Terry A Potter

William E Slack

Stephen D Seneker

Peter H Markusch

Hartmut Knofel

Michael K Lowery

Louis Renbaum

Larry W Arndt

Clarence D Ferrell

Disclosed herein is a process for recovering toluene diisocyanate (TDI) from a TDI residue solution, comprising mixing the residue solution with a polyisocyanate consisting essentially of methylenediphenyl diisocyanate (MDI) or MDI in combination with its higher ring oligomer, followed by heating the resulting mixture over a temperature range of 130.degree. to 250.degree. C. for a period of time sufficient to remove free TDI and thermally splittable TDI generated from equilibration of the TDI residue with MDI or the MDI oligomer by either a batch or continuous process.

Toluene diisocyanate residue

The present invention is directed for preparing a 4,4'-diisocyanato dicyclohexylmethane which contain a relatively high amount of the trans,trans-isomer. The process broadly comprises (a) melting a mixture of 4,4'-diisocyanato dicyclohexyl-methane isomers, (b) cooling the melted mixture to form: (1) a liquid phase and (2) a solid phase, (c) removing said liquid phase, which is a commercially viable product itself, (d) heating the solid phase and removing that portion of the solid phase which has melted, and (e) recovering that portion of said solid phase which has not melted by heating the remaining portion.

Melt crystallization process for preparing high trans, trans-isomer

The present invention is directed to a simple process for preparing a 4,4'-diisocyanato dicyclohexylmethane containing at least 90% by weight of the trans, trans-isomer. More particularly, the process comprises:

Process for preparing high trans, trans-isomer containing

The present invention is directed to a process for reducing the free monomer content of polyisocyanate adduct mixtures wherein the adduct has an average isocyanate functionality of greater than about 1.8 which comprises treating the polyisocyanate adduct mixture in the presence of 2 to about 30 percent by weight of an inert solvent, based on the weight of the polyisocyanate mixture, in an agitated thin-layer evaporator under conditions sufficient to reduce the free monomer content of the polyisocyanate adduct mixture below that level which is obtainable in the absence of a solvent.

Reduction of free monomer in isocyanate adducts

Aliphatic and/or cycloaliphatic polyisocyanates containing allophanate groups are produced by reacting (a) a di- and/or polyisocyanate with aliphatic and/or cycloaliphatic isocyanate groups with (b) a hydroxy compound at a temperature of at least 150.degree. C. for no more than 90 minutes and then rapidly cooling the reaction mixture to a temperature of less than 100.degree. C. It is preferred that the reaction be carried out in the absence of oxygen. The products thus obtained are virtually colorless, have a relatively low viscosity and excellent storage stability.

Process for the production of polyisocyanates containing allophanate

The instant invention is directed to a process for the preparation of mixtures of polyamines of the polyamino-polyaryl-polymethylene type whereby the proportion or the ortho-substituted products are substantially increased. This increase is brought about by adding the acid catalyst to the aromatic amine/formaldehyde reaction mixture in two or more stages.

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New Martinsville, WV, United States of America

Kenneth L Dunlap