Process for the purification from heavy metals of vinyl chloride polymers
US8053550B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 21, 2005 |
| Grant date | Nov 8, 2011 |
| Priority date | — |
| Expiry date | Sep 10, 2026 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02W30/62
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Process for the purification of a vinyl chloride polymer (PVC) comprising at least one compound of a heavy metal, according to which: (a) the PVC is dissolved in a water-miscible polar organic solvent; (b) an aqueous solution comprising a reagent, which is either a base capable of reacting with the compound of the heavy metal (R1) or a dispersing agent capable of stabilizing the said compound (R2), is added to the organic solution, the water being introduced in an amount (Q) such that it brings about the formation of a two-phase medium, the continuous phase of which is the organic phase; (c) the two-phase medium is subjected to stirring for a time sufficient for the reagent to be able to interact with (exert its effect on) the compound of the heavy metal; (d) the precipitation of the PVC out of this two-phase medium is brought about.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.