Process for distillation of crude isocyanate concentrates
US5043470A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Jun 1, 1990 |
| Grant date | Aug 27, 1991 |
| Priority date | — |
| Expiry date | Jun 1, 2010 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C263/20
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process is described for the separation and recovery of isocyanate monomers from isocyanate concentrates which leaves a residue which is liquid and burnable. The process for the separation and recovery of isocyanate monomers from isocyanate concentrates formed in the production of isocyanates and comprising a volatile isocyanate monomer and by-products comprises the steps of: PA0 (A) preparing a mixture comprising PA1 (A-1) the isocyanate concentrate; and PA1 (A-2) an oil solution comprising; PA2 (A-2-a) a major amount of hydrocarbon oil, and PA2 (A-2-b) a minor amount of at least one carboxylic ester obtained by reacting PA3 (A-2-b-1) at least one substituted succinic acylating agent with PA3 (A-2-b-2) at least one alcohol of the general formula EQU R.sub.3 (OH).sub.M (I) PA3 wherein R.sub.3 is a monovalent or polyvalent organic group joined to the OH groups through carbon bonds, and m is an integer of from 1 to about 10; and PA0 (B) heating the mixture to an elevated temperature whereby isocyanate monomer is distilled and recovered leaving a liquid residue. The presence of the oil solution in the mixture facilitates the distillation of the isocyanate concentrate, generally impr…
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