Polydithiocarbamate resin
View Patent ↗The present invention is directed to a solid chelating resin consisting of a reactive hydrophobic backbone having pendent carbodithioic groups. Preferably the resin is a poly(dithiocarbamate) containing no tertiary nitrogen groups. The invention is also directed to a novel process for making a chelating resin involving a) reacting a nucleophilic compound with carbon disulfide in a suitable solvent, to form a carbodithioic acid, b) neutralizing the carbodithioic acid with a base to form a carbodithioic acid salt; and c) reacting said carbodithioic acid salt with a crosslinking reagent in a suitable solvent to form a solid chelating resin. The chelating resin is useful in removing metals and cationic compounds from effluent streams.
1. A process for producing a chelating resin comprising:
reacting a nucleophilic compound with carbon disulfide in a solvent, to form a carbodithioic acid;
neutralizing said carbodithioic acid with a base to form a carbodithioic acid salt; and
reacting reactive sites on said carbodithioic acid salt with a crosslinking reagent in a solvent to form a solid chelating resin.
2. The process of claim 1 wherein said chelating resin comprises a (poly)dithiocarbamate resin.
3. The process of claim 1 wherein said nucleophilic compound comprises an amine.
4. The process of claim 3 wherein said amine comprises a polyamine.
5. The process of claim 4 wherein said polyamine comprises polyethyleneimine polyamine.
6. The process of claim 1 wherein the molar ratio of carbon disulfide to reactive nucleophilic sites is from 0.1:1.0 to 0.9:1.0.
7. The process of claim 6 wherein the molar ratio of carbon disulfide to reactive nucleophilic sites is from 0.3:1.0 to 0.7:1.0.
8. The process of claim 1 , wherein said nucleophilic reaction occurs at a pH of from 7.0 to 13.0.