Production and use of 3,4′ and 4,4′-dimethylbiphenyl isomers
US11236028B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 8, 2019 |
| Grant date | Feb 1, 2022 |
| Priority date | — |
| Expiry date | Jan 8, 2039 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C2601/14
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Processes are described for separating 3,4′- and 4,4′-dimethylbiphenyl from a mixture comprising at least 3,3′-, 3,4′- and 4,4′-dimethylbiphenyl. In the processes, the mixture is cooled to produce a crystallization product comprising at least of the 4,4′-dimethylbiphenyl from the feed mixture and a first mother liquor product. The first mother liquor product is distilled to produce a bottoms stream enriched in 4,4′-dimethylbiphenyl as compared with the first mother liquor product and an overhead stream deficient in 4,4′-dimethylbiphenyl as compared with the first mother liquor product. The overhead stream is then cooled to produce a second crystallization product comprising at least part of the 3,4′-dimethylbiphenyl from the overhead stream and a second mother liquor product.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.