Borchi Kat 0243 accelerates the chemical reaction between the alcohol and isocyanate component of polyurethane coating systems, thus allowing optimum steering of the drying properties, both during force-drying and curing at room temperature. The use of Borchi Kat 0243 ensures fast blocking stability of polyurethane coatings. Moreover improves solvent resistance, high film hardness and early sandability of the coating. Borchi Kat 0243 can be used as a replacement for dibutyl tin dilaurate (DBTL), in many systems yielding better properties, e.g. reduced yellowing and higher film hardness, than DBTL catalysed systems.