Abstract: A liquid agent for de-icing and protecting against icing-up is described, by means of which it is possible, in particular, to free the metal surface of aircraft rapidly and completely from ice, hoar-frost, snow and the like, and to protect the surface against further build-up for a relatively long period. The agent is essentially composed of several components, namely of (a) glycols, (b) water, (c) thickeners, (d) substances insoluble in water, (e) surface-active agents, (f) corrosion inhibitors and (g) alkaline compounds, in very specific quantities in each case, the quantity of the components (a) and (b) being at least 94%, relative to the total weight of the agent. Its pH value is 7.5 to 10.

Abstract: 2-(perfluoroalkyl)-ethanols of the formulaR.sub.f CH.sub.2 CH.sub.2 OHin which R.sub.f is a perfluoroalkyl radical having from 1 to 21 carbon atoms, are prepared in an advantageous manner from the corresponding 2-(perfluoroalkyl)-ethyl iodides by reaction with water and N-methyl-2-pyrrolidone, thus reducing formation of by-products.

Abstract: 2-(perfluoroalkyl)-ethanols of the formula R.sub.f CH.sub.2 CH.sub.2 OH are obtained from 2-(perfluoroalkyl)-ethyl iodides of the formula R.sub.f CH.sub.2 CH.sub.2 I as a mixture with 2-(perfluoroalkyl)-ethylenes of the formula R.sub.f CH.dbd.CH.sub.2 and possibly also with 2-(perfluoroalkyl)-ethylcarboxylic acid esters of the formula R.sub.f CH.sub.2 CH.sub.2 OCOR. From these mixtures, the 2-(perfluoroalkyl)-ethanols are obtained with a high purity degree when adding during the distillation separation as entrainer an alkanol having from 1 to 8 carbon atoms or a monoalkyl ether of ethyleneglycol the alkyl radical of which contains 1 to 4 carbon atoms, or a mixture of such alkanols and/or alkylglycols, and in the presence of 2-(perfluoroalkyl)-ethylcarboxylic acid esters, furthermore an acidic ester interchange catalyst.