Rubber devulcanization process
US5602186A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 27, 1995 |
| Grant date | Feb 11, 1997 |
| Priority date | — |
| Expiry date | Oct 27, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02W30/62
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A process for devulcanizing a rubber vulcanizate by desulfurization involves suspending a rubber vulcanizate crumb in a solvent which preferably swells the rubber vulcanizate before or during the devulcanization reaction and adding an alkali metal, such as sodium, to the suspension. The alkali metal cleaves mono-, di- and polysulfidic cross-linkages in the rubber vulcanizate to liberate rubber polymer having a molecular weight substantially equal to that of the rubber polymer prior to vulcanization. Carbon black may also be recovered for re-use in accordance with the process of the present invention. Devulcanized rubber may be subjected to a re-vulcanization reaction without separation of rubber polymer from the solvent by addition of an appropriate curing mixture.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.