| abstract |
Diols containing perfluoroalkyl radicals are produced by reacting compounds of the formula Rf-(E)m-X'-H (Rf=perfluoroalkyl radical, E is an alkylene group optionally interrupted by certain groups and/or substituted at the end, m=0 or 1, X'-H=-CONRH, -SO2NRH or -SH) in a first step with diols containing at least 2 halogen atoms. Preferably the obtained products are reacted in a second reaction step with polyvalent isocyanates to prepolymers with free -NCO- or free -OH-groups and these prepolymers are reacted in a third step with compounds containing isocyanate groups and/or hydroxyl groups. The first reaction step is carried out in an aprotic solvent which is insoluble in water, in the presence of an aqueous solution of an alkali metal carbonate. Intermediate products have not to be isolated. The obtained polyurethanes can be used in form of aqueous dispersions for the oil- and water repellent finishing of textiles. |