Title:
2,4′-MDIの製造方法
Document Type and Number:
Japanese Patent JP5001558
Kind Code:
B2
Abstract:
Preparation of 2,4'-methylene diphenylene diisocyanate (MDI) comprises distillation of a diisocyanatodiphenylmethane isomer mixture from 2,2'-diisocyanatodiphenylmethane, 2,4'-diisocyanatodiphenylmethane and 4,4'-diisocyanatodiphenylmethane to give a mixture comprising 2,4'-diisocyanatodiphenylmethane (85-99 wt.%), 4,4'-diisocyanatodiphenylmethane (up to 15 wt.%) and 2.2'-diisocyanatodiphenylmethane (up to 0.2 wt.%). Preparation of 2,4'-methylene diphenylene diisocyanate (MDI) (with less production of 2,4'-MDI) comprises distillation of a diisocyanatodiphenylmethane isomer mixture from 2,2'-diisocyanatodiphenylmethane, 2,4'-diisocyanatodiphenylmethane and 4,4'-diisocyanatodiphenylmethane to give a mixture comprising 2,4'-diisocyanatodiphenylmethane (85-99 wt.%), 4,4'-diisocyanatodiphenylmethane (up to 15 wt.%) and 2.2'-diisocyanatodiphenylmethane (up to 0.2 wt.%) (where: distillation is carried out in a single-step; a partition column is used in at least one distillation stage; a destillative before separation is upstreamed to the partition column before distillation to give a mixture (comprising 2,2'-diisocyanatodiphenylmethane (0-15 wt.%), 2,4'-diisocyanatodiphenylmethane (12-60 wt.%) and 4,4'-diisocyanatodiphenylmethane (25-88 wt.%)), which is used as feed stream to the partition column; and the vapor at the top of the partition column is condensed and 98-99.6% of it returns to the top zone).
Inventors:
Hans-Peter Charl
Ulrich Wolf
Ulrich Wolf
Application Number:
JP2006020882A
Publication Date:
August 15, 2012
Filing Date:
January 30, 2006
Export Citation:
Assignee:
Bayer MaterialScience AG
International Classes:
C07C263/20; C07C265/14
Domestic Patent References:
| JP2004331667A | ||||
| JP2004529115A | ||||
| JP53009750A | ||||
| JP2004143173A |
Foreign References:
| WO2004056759A1 |
Attorney, Agent or Firm:
Toshio Yano
Takuya Kuno
Einzel Felix-Reinhard
Takuya Kuno
Einzel Felix-Reinhard