hdi closed  covesro bl 3370   about: blocked aliphatic hdi-polyisocyanate. to formulate lightfast one-component stoving polyurethane coatings with high themal yellowing resistance; as an additive to improve flexibility and adhesion. product types: hdi pic aliphatic polyisocyanate crosslinkers polyisocyanate hardeners polyisocyanurate isocyanate material: coatings, paints & inks solventborne, flexible, thermally resistant, elastic general characterization: desmodur bl 3370...