The invention relates to a method of preparing an aliphatic polyisocyanate by conversion of an aliphatic diisocyanate to a polyisocyanates in the presence of a catalyst, wherein the catalyst contains a saline compound having 5 to 97.1 wt. % of a 1,2,3- and/or a 1,2,4-triazolate (calculated as C2N3, molecular weight 66) in the anion, the isocyanates thus prepared and the polyurethane paints and coatings containing them.