Methods of using N-oxyl polymerization inhibitor in a wash settler for preparing methyl methacrylate
US10640449B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Dec 8, 2017 |
| Grant date | May 5, 2020 |
| Priority date | — |
| Expiry date | Dec 8, 2037 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C69/54
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
The present invention provides methods comprising washing or, preferably, washing and neutralizing a sulfur acid containing crude MMA stream to generate a two phase stream containing at least methacrylic acid, methacrylamide (MAM), water and methanol, and an organic component containing methyl methacrylate and thereby form an aqueous component; including in any of the organic component, the aqueous component of a neutralized sulfur acid containing crude methyl methacrylate (MMA) stream or the organic component of a neutralized sulfur acid containing crude methyl methacrylate (MMA) stream one or more N-oxyl compound polymerization inhibitor; followed by separating the aqueous component from the organic component, thereby forming a treated crude MMA stream and an aqueous stream to remove residual (meth) acrylic acid.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.