Process for removing impurities from perfluorinated alkyl bromides or alkylene dibromides
AssigneeHoechst Aktiengesellschaft
InventorKlaus Raab
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Abstract
Mixtures of perfluorinated alkyl bromides or alkylene dibromides containing perfluorinated iodine compounds are irradiated with electromagnetic radiation in the wavelength range from 230 to 500 nm and brought into contact, either during the irradiation or directly thereafter, with at least one of the following agents: active charcoal, certain finely divided metals, lower aliphatic alcohols, chlorine, bromine, oxygen, hydrogen peroxide, aqueous or alcoholic solutions of alkali metal compounds with certain inorganic anions or lower aliphatic alcohols. After removal of the agent and if appropriate distillation, products which contain less than 0.0005% by weight of iodine compounds and can be employed, for example, in the medical sector can be obtained.
Claims9
A process for removing impurities from a compound or compounds of the formula
- X(CF.sub.2).sub.n Br (I)
- in which
- X is F, (CF.sub.3).sub.2 CF or Br and
- n is a number from 2 to 16,
- which comprises irradiating the mixture to be purified with electromagnetic radiation in the wavelength range from 230 to 500 nm, bringing the mixture into contact, during or after the irradiation, with at least one of the following agents:
- active charcoal;
- a finely divided solid selected from the group consisting of Cu, CuI, Ag, Mg, Zn, Al, Mn, Fe, Co, Ni and an alkali metal borohydride;
- chlorine, bromine, oxygen ;
- aqueous solutions of H.sub.2 O.sub.2, other inorganic peroxidic compounds or alkali metal salts with the following anions:
- SO.sub.3.sup.2-, S.sub.2 O.sub.3.sup.2-, PO.sub.3.sup.3-, NO.sub.2.sup.-, CO.sub.3.sup.2-, HCO.sub.3.sup.-, BrO.sub.3.sup.-, ClO.sub.3.sup.- ;
- aqueous or alcoholic solutions of alkali metal hydroxides, iodides or alcoholates or lower aliphatic alcohols, removing the agent after the treatment has ended and, optionally washing the mixture to be purified with water and distilling it.
Dependencies are inferred from the claim text.