Low-functionality isocyanate based on hexamethylene diisocyanate (HDI). To improve the storage stability of pigmented moisture-curing one-component polyurethane coatings with good lightfastness and weather stability. Properties / Applications: Beginning at 50 °C, Desmodur® LD reacts with water, releasing carbon dioxide and acting as a dewatering agent to ensure the storage stability of pigmented moisture-curing one-component polyurethane coatings. The stoichiometric conversion of 1 g water requires approx. 40 g Desmodur® LD. However, trials and actual use have shown that the best results are achieved using double to three times this quantity of Desmodur® LD. The reactivity of Desmodur® LD with water is comparable with that of the aliphatic Desmodur® E products. Drying of the pigments, extenders and solvents with Desmodur® LD must therefore be carried out before addition of the main binder to prevent undesired reactions and an increase in viscosity. In the ready-to-use formulation, the content of Desmodur® LD in the total binder should not exceed 30 %, calculated on the solvent-free resin. Information provided by Covestro |