Bayer Corporation

Miles Inc.

Mobay Corporation

Clarence D Blue

Rick L Adkins

Steven L Schilling

Jeffrey S Bolton

Ramon Kalyanaraman

Brian H Peterson

William E Slack

Kenneth P Yonek

William J Nicola

Kirk J Bourgeois

Roger C Suter

Frank C Rossitto

Ricky L Adkins

Mark R Kratz

This invention relates to a process for the reduction of color of polymethylene poly(phenylisocyanates). This process comprises mixing a polymethylene poly(phenylisocyanate) with an epoxide having an epoxide equivalent weight of about 44 to about 700, and heating this mixture to a temperature of from about 35 to about 150.degree. C. for at least about 15 minutes, with stirring. Suitable epoxides include epoxidized fatty acid monoglycerides, epoxidized fatty acid diglycerides, epoxidized fatty acid triglycerides, epoxidized dimer fatty acids and epoxidized trimer fatty acids.

Color reduction of polymethylene poly (phenylisocyanates)

The present invention relates to an improved process for the production of light colored polymethylene polyphenyl polyisocyanates. This process comprises adding a compound that contains an epoxide group to the process at any point prior to quench cooling the formed polyisocyanates.

Polymeric MDI color reduction

NCO-terminated prepolymers are made by reacting a polymeric diphenylmethane diisocyanate (PMDI) and a polyol having a functionality of from about 1.8 to about 4.0 and a molecular weight of from about 400 to about 2,000. The PMDI and polyol are reacted in amounts such that the equivalent ratio of isocyanate groups to hydroxyl groups is from about 15:1 to about 160:1. These prepolymers are useful in the production of polyurethane foams, particularly laminated foams.

Isocyanate-terminated prepolymers and rigid-foams produced therefrom

A process for the production of polymethylene polyphenyl polyisocyanates is disclosed. The process comprises phosgenating the corresponding polyamines in solution in an inert organic solvent, removing excess phosgene, and stripping the solvent, the improvement wherein at least 0.00015 percent by weight of hydrazine or hydrazine derivative per 100 percent by weight of polyamine are added to the polyamines at any time prior to the stripping step.

Polymeric MDI color

Disclosed herein is an improved process for preparing a polyamine mixture derived by reacting aniline with formaldehyde in the presence of an acid catalyst the improvement comprising mildly reducing the polyamine mixture by a process step comprising catalytically or chemically hydrogenating the polyamine mixture in the presence of a metal catalyst.

Process for preparing polyamines and polysocyanates

The present invention encompasses an improved process for preparing polymethylene polyphenyl polyisocyanate comprising reacting phosgene with polymethylene polyphenyl polyamine, the improvement wherein the polymethylene polyphenyl polyamine is acidified prior to phosgenation.

Process for preparing polyamines for lighter color polyisocyanate based

The present invention is directed to a process for the production of polymethylene polyphenyl polyisocyanates by phosgenating the corresponding polyamines in solution in an inert organic solvent, removing excess phosgene, and stripping the solvent. The improvement resides in adding at least 0.02 parts by weight of reducing agent per 150 parts by weight of polyamine to the polyamines at any time prior to the stripping step.

Color reduction of polymethylene polyphenyl polyisocyanates

The present invention is directed to a liquid, storage-stable isocyanate prepolymer having an isocyanate group content of from 10 to 30% by weight, prepared by reacting:

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New Martinsville, WV, United States of America

Clarence D Blue