| Hydrophilic aliphatic polyisocyanate based on hexamethylene diisocyanate (HDI). Hardener for near zero VOC waterborne 2K polyurethane coatings. Properties / Applications: Because of its hydrophilic character, Bayhydur® XP 2547 can be easily dispersed in the aqueous phase. It is used primarily as the crosslinking agent for waterborne polyol binders (Bayhydrol®). The dispersibility of the product in water is influenced by organic cosolvents. The use of highly hydrophobic or highly hydrophilic cosolvents such as butyl acetate, xylene, butyl glycol acetate, dimethyl formamide or N-methylpyrrolidone generally leads to a coarser dispersion, which may cause turbidity in the coating film depending on the entire system. On the other hand, the use of, for example, methyl ethyl ketone, methoxypropyl acetate, dipropylene glycol dimethyl ether, propylene glycol diacetate or dicarboxylic acid diester mixtures leads to fine-particle dispersions. Bayhydur® XP 2547 can also be added to conventional OH-free dispersions to improve their property profiles. Information provided by Covestro |
