C - Chemistry – Metallurgy – 07 – C
Patent
C - Chemistry, Metallurgy
07
C
202/80
C07C 118/02 (1980.01)
Patent
CA 1113032
ABSTRACT OF THE DISCLOSURE In a process for purifying and reducing the acidity of a poly- methylene polyphenylpolyisocyanate mixture wherein the mixture is subjected to a distillation step, such as by passing a flowing stream of a crude poly- methylene polyphenylpolyisocyanate mixture through a distillation column which has a reboiler means consisting of a thin film evaporator apparatus mounted therewith for rapidly heating the stream to about 190°C. to about 250°C. whereby the solvent and impurities are taken overhead, and then allow- ing the distillation residue of polymethylene polyphenylpolyisocyanate to cool, an improvement is disclosed which comprises maintaining the distilla- tion residue of the polymethylene polyphenylpolyisocyanate at a temperature minutes and then recirculating continuously a portion of the distillation residue to the distillation column for admixture with the flowing feed stream of crude polymethylene polyphenylpolyisocyanate at a recirculation rate of from about 1:1 to about 3:1 volumes of isocyanate distillation residue per volume of crude isocyanate feed. The acid level of the polymethylene poly- phenylpolyisocyanate mixture treated by the improved process of the invention is substantially reduced without adversely affecting the isocyanate equiva- ent weight, viscosity or other physical and chemical characteristics of the product.
312529
Burns Simon P.
Walton John M.
Smart & Biggar
Texaco Development Corporation
LandOfFree
Process for reducing the acidity of organic polymeric... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process for reducing the acidity of organic polymeric..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for reducing the acidity of organic polymeric... will most certainly appreciate the feedback.
Profile ID: LFCA-PAI-O-21146