Reactive wax additives for hydrophobization of waterborne acrylic emulsions for usage as binders in clear and pigmented coatings are disclosed herein. The reactive additives comprise dispersions of alkyl ketene dimers stabilized by cationic starch. The process of hydrophobization of acrylate emulsion is carried out by reaction with alkyl ketene dimer waxes during emulsion polymerization of the same.