Title:
PRODUCTION OF DIPHENYLMETHANEDIISOCYANATE-BASED POLYISOCYANATE
Document Type and Number:
Japanese Patent JP3292857
Kind Code:
B2
Abstract:
PURPOSE: To provide a producing method not only producing a MDI-based polyisocyanate which is not colored or remarkably reduced in coloring, but simultaneously capable of also preventing coloring during storage.
CONSTITUTION: In producing diphenylmethanediisocyanate-based polyisocyanate by subjecting a condensation product obtained by condensing aniline with formaldehyde in the presence of a catalyst or a diaminodiphenylmethane-based polyamine to phosgenation, this producing method is carried out by adding an organic phosphorous acid before carrying out phosgenation reaction. As necessary, the phosgenation product is separated into diphenylmethanediisocyanate and polyphenylenepolymethylenepolyisocyanate.
Inventors:
Fukutomi Yorito
Yokoyama Tsunehiro
Yusuke Aoki
Yokoyama Tsunehiro
Yusuke Aoki
Application Number:
JP24966693A
Publication Date:
June 17, 2002
Filing Date:
September 13, 1993
Export Citation:
Assignee:
Nippon Polyurethane Industry Co., Ltd.
International Classes:
C07B61/00; C07C263/10; C07C265/14; C08G18/76; (IPC1-7): C08G18/76; C07C263/10; C07C265/14
Domestic Patent References:
| JP4211641A | ||||
| JP5148619A | ||||
| JP4159259A | ||||
| JP462091B1 |
Attorney, Agent or Firm:
Okazaki Hideo