Method for separating transition metals from polymers
AssigneeRoehm GmbH
InventorsThorsten Goldacker, Klaus Koralewski
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Abstract
The invention relates to a method for separating transition metals from polymers. According to the invention, a solid polymer containing transition metals is treated with an extracting agent, the duration of the treatment and the extraction temperature being selected in such a way that the transition metal content is reduced by at least 30 wt. %.
Claims18
A process for removal of transition metals from polymers, characterized in that it comprises extracting transition metals from a solid polymer via treatment with an extractant,
- where the solid polymer is obtainable via polymerization of alkyl (meth)acrylates or of mixtures which comprise alkyl (meth)acrylates, and the extractant encompasses alcohols having from 1 to 4 carbon atoms and/or water.
The process as claimed in any of the preceding claims, characterized in that the solid polymer comprises, as transition metal, Cu, Fe, Co, Cr, Ne, Sm, Mn, Mo, Ni, Ag, Zn, Pd, Pt, Re, Rh, Ir, In, Yb, and/or Ru.
The process as claimed in any of the preceding claims, characterized in that the solid polymer comprises at least 100 ppm of transition metal, prior to the treatment.
The process as claimed in any of the preceding claims, characterized in that chelating ligands which comprise N atoms are added to the extractant.
The process as claimed in any of the preceding carried out at a temperature in the range from 0 to 120° C.
The process as claimed in any of the preceding claims, characterized in that the treatment is carried out for a period in the range from 1 hour to 4 days.
The process as claimed in any of the preceding claims, characterized in that the constitution of the mixture used for the extraction process is varied during the treatment.
The process as claimed in any of the preceding claims, characterized in that the metal content of the polymer falls by at least 70% by weight.
The process as claimed in any of the preceding claims, characterized in that the solid polymer is granulated before carrying out the treatment with an extractant.
The process as claimed in any of the preceding claims, characterized in that the solid polymer is obtainable via a process in which ethylenically unsaturated monomers are polymerized by means of initiators which have a transferable atomic group and by means of one or more catalysts which encompass at least one transition metal, in the presence of ligands which can form a coordination compound with the metallic catalyst(s).
Dependencies are inferred from the claim text.