Process for separating and recovering the constituents of an exhausted solvent mixture used for cleansing reactors for the polymerization of vinyl chloride
US4043874A · kind A · utility
2Cited by
7References
7Claims
0Family size
Assignee
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Key dates
| Filing date | Dec 16, 1976 |
| Grant date | Aug 23, 1977 |
| Priority date | — |
| Expiry date | Dec 16, 1996 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01D3/36
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
The constituents of an exhausted toluene-dimethylformamide solvent mixture used for removing polyvinyl chloride deposits from polymerization reactors, are separated by adding water to said mixture and distilling off toluene, thereby to obtain a distillation residue having a water content of at least 2 wt.% and a toluene content not exceeding 10 wt.%, precipitating the polymer by cooling the distillation residue, adding a further amount of water, distilling off any toluene present, recovering the precipitate and distilling the residual aqueous solution to recover the dimethylformamide.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.