Menetelmä alkyyliketeenidimeerien valmistamiseksi

The present invention relates to a method for producing alkyl ketene dimers from fatty acid mixtures containing saturated and unsaturated fatty acids of vegetable, or tall oil origin, as well as the use of said alkyl ketene dimer products obtained for the hydrophobic sizing of paper. Further, the invention relates to an improved mehtod for producing fatty acid chlorides. In the method, dried fatty acid mixture containing unsaturated and/or saturated C6-C24 carboxylic acids is evenly added to phosphorus trichloride at the temperature of 45-100 DEG C, the acid chloride product obtained is isolated, and reacted with a dimerizing reagent in the absence of a solvent, or in a solvent or solvent mixture, at the temperature of 20-100 DEG C.