at 80 u00b0 c for another 2 hours and a mixture is thus obtained containing mostly the addition product of t butylaminoethyl methacrylate in the 2 position and of perfluorohexylethanol in the 4 and 6 positions together with a molar proportion of 42 of products of symmetrical diadditions this mixture is heated to 90 u00b0 c and 0 5 part of lauroyl peroxide and 0 2 part of t butyl perpivalate are then added to it and this addition of initiators is repeated after 2 and 4 hours reaction after 6 hours at 90 the reaction is finished the solution s 15 obtained is yellow brown and clear it contains 32 8 nonvolatiles and 11 2 of fluorine this solution is diluted with methyl isobutyl ketone to a fluorine content of 0 15 and is then applied to the same leather as in example 14 at a rate of 200 g m 2 after drying overnight at ambient temperature the following results are obtained 180 parts of trichlorotrifluoroethane 34 8 parts 0 2 mole of toluene diisocyanate mixture containing 80 of 2 4 isomer and 20 of 2 6 isomer and 0 2 parts of dibutyltin dilaurate are introduced into a reactor which is identical to that in example 1 after the air in the reactor has been purged with a stream of dry nitrogen and the temperature has been raised to 50 u00b0 c solvent reflux a solution of 72 8 parts of perfluorohexylethanol c.