Process for the elution of fluorinated emulsifiers
AssigneeDyneon LLC
InventorsStephan Führer, Gernot Löhr, Werner Schwertfeger
Life of this patent
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Abstract
Fluorinated emulsifier acids bound to an anion exchanger resin can be eluted using a mixture of water, a compound of the formula M—X, in which M is an alkali metal or an alkylammonium ion, and X is hydroxyl, fluoride or chloride, and at least one organic solvent which completely dissolves the other components. For work-up of the eluent, this is advantageously subjected to steam distillation until all volatile constituents have been essentially removed, and the emulsifier acid is liberated from the steam distillation residue using a sufficiently strong acid. This emulsifier acid can advantageously be distilled off and collected as the ammonium salt in aqueous ammonia solution.
Claims13
A process for elution of a fluorinated emulsifier bound to an anion exchanger resin, wherein the resin is brought into contact with a mixture consisting essentially of:
- a) water,
- b) a compound of the formula
- M—X
- in which M is an alkali metal or alkylammonium ion, and X is hydroxide, fluoride or chloride, and
- c) at least one organic solvent which completely dissolves the other components a) and b) and thus provides a sufficient quantity of anions X−for elution of the emulsifier from the anion exchanger resin.
A process for the work-up of an eluate comprising:
- a) providing a fluorinated emulsifier bound to an anion exchange resin;
- b) contacting the resin with a mixture consisting essentially of:
- i) water,
- ii) a compound of the formula
- M—X
- in which M is an alkali metal or alkylammonium ion, and X is OH, F, or Cl, and
- iii) at least one organic solvent which completely dissolves the other components
- i) and ii) and thus provides a sufficient quantity of anions X− for elution of the emulsifier from the resin;
- c) subjecting the eluate to steam distillation until the eluate is essentially free from volatile constituents;
- and
- d) treating the steam distillation residue with an acid sufficiently strong to liberate a free acid form of the emulsifier.
Dependencies are inferred from the claim text.