Method for intermittently producing 4,4′-diaminodicyclohexylmethane with a low amount of the trans-trans isomer
US8759591B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Jun 3, 2011 |
| Grant date | Jun 24, 2014 |
| Priority date | — |
| Expiry date | Jun 3, 2031 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C2601/14
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
The present invention discloses a method for intermittently producing 4,4′-diaminodicyclohexyl methane (H12MDA) with a low amount of the trans-trans isomer thereof, which comprises: controlling the reaction process by stopping the reaction when, except for a solvent, the reaction solution comprises MDA of 0-5 wt % and H6MDA of 1-20 wt %; and b) separating the reaction solution obtained from step a) by conventional means to obtain H12MDA product with desired purity, and allowing the un-reacted material and intermediate product to be recycled to the reactor after being accumulated. The method of the present invention decreases the amount of the trans-trans isomer in H12MDA, increases the yield of the reaction, and reduces the production cost. The present invention also provides a post treatment process of the reaction mixture.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.