Login| Sign Up| Help| Contact|

Patent Searching and Data


Title:
PREPARATION OF MIXTURE OF DIPHENYLMETHANE DIISOCYANATE AND POLYPHENYLPOLYMETHYLENE POLYISOCYANATE HAVING REDUCED IODINE COLOR NUMBER
Document Type and Number:
Japanese Patent JPH04211641
Kind Code:
A
Abstract:

PURPOSE: To inhibit corrosion of apparatus by a mixture containing chlorine, hydrogen chloride and phosgene formed upon addition of water and to match the iodine color number of crude MDI to a level achievable by the addition of water or to reduce it.

CONSTITUTION: A crude DMA comprising diphenylmethane-diamine and polypheny-polymethylene-polyamine compound is reacted in a solvent under heating. After completion of phosgenation, the excess phosgene and the solvent are removed and further heated to give a mixture (crude MDI) of diphenylmethane-diisocyanate and polyphenyl-polymethylene-polyisocyanate. After the end of the phosgenation, a low molecular weight alkanol and/or a polyhydric alcohol are added to the phosgene-containing reaction mixture, thereby to inhibit dark coloration or discoloration.


Inventors:
DEETORITSUHI SHIERUTSUAA
ROORANTO MINGESU
BUERUNAA RANGAA
BERUNTO BURUFUMAN
BUORUFUGANGU HAIDAA
PEETAA KERAA
ARUNORUTO SHIYUMITSUTO
BUIRII BUAN PEE
Application Number:
JP3409591A
Publication Date:
August 03, 1992
Filing Date:
February 28, 1991
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
BASF AG
International Classes:
C07C263/18; C07C263/20; C07C265/14; (IPC1-7): C07C263/18; C07C265/14
Attorney, Agent or Firm:
Tajiro Taiji