| 摘要 |
The purificn. comprises passing per fluoro polyether(s) (I) in gaseous form over a copper-magnesium silicate catalyst at 200-400 deg.C and collecting in an aq. alkali hydroxide soln. Pref. 20-500 pts.wt. (I) per hr. are passed over 1000 pts.wt. of the silicate catalyst which is used in an oxidised state. Pref. element(s) from Gps. IA, IIA, IIIA, IVA, IB, IIB, IVB or VIB are used as co-catalyst. Oxides of Cr, Na, K, Ba and/or Zn are pref. as co-catalysts. The silicate catalyst contains 10-40 wt.% CuO and 0.1-10 wt.% co-catalyst. The alkali hydroxide soln. comprises 100-250 g/l potassium or sodium hydroxide. (I) with a b.pt. greater than 300 deg.C are contacted with the silicate catalyst at less than 0.1 bar. USE/ADVANTAGE - Useful for the removal of toxic and reactive fluorinated by prods. in (I) and prevents reformation. The process operates at high yield with low loss of (I). |
