Process for the preparation of sulfamic acid
US4386060A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 29, 1982 |
| Grant date | May 31, 1983 |
| Priority date | — |
| Expiry date | Jan 29, 2002 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01B21/096
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Processes for the production of sulfamic acid by the reaction of urea, sulfuric anhydride, and sulfuric acid in (1) a two-stage process wherein the sulfuric anhydride used in the first stage at a temperature less than 50.degree. C. is dissolved in a halogenated fluorocarbon or a mixture of halogenated fluorocarbons having a boiling point of from 0.degree. to 50.degree. C. or (2) in a one-stage process at 60.degree. to 100.degree. C. with the sulfuric anhydride dissolved in a halogenated fluorocarbon or a mixture of halogenated fluorocarbons having a boiling point below 100.degree. C. at atmospheric pressure, the halogenated fluorocarbon serving to remove the heat generated by the exothermic formation of the sulfamic acid from the original reactants.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.