To reclaim a vulcanized rubber in a polymeric state by adding a nucleophilic reagent to the vulcanized rubber so as to suppress the thermal decomposition of the rubber main chain without the need of using any reclaiming oil or dipentene having adverse effect in compounding the reclaimed rubber in a fresh rubber again.
This reclamation is performed as follows: a nucleophilic reagent is added to a rubber vulcanized with sulfur followed by heat treatment of the vulcanized rubber in a carbon dioxide atmosphere under the supercritical conditions for carbon dioxide (for example, at 150-250°C under 80-800 atm) and the resulting reclaimed rubber is discharged; wherein it is preferable that, before the above discharging operation, the remaining nucleophilic reagent in the heat-treated rubber is extracted with carbon dioxide under its supercritical condition (pref. at 30-200°C or so under 80-800 atm) and removed. The above nucleophilic reagent to be used is pref. at least one kind selected from thiol compounds (e.g. thiophenol), amine compounds (e.g. aniline) and phosphorus compounds (e.g. triphenylphosphine).
OGAWA KAZUYUKI
TODO KIMIO
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