Urethane resins are produced by the reaction of isocyanates with polyols. Among polyether and polyester polyols, particularly Kraemer-specific polyol derivatives are used. Especially with those last mentioned structures good adhesion and intercoat adhesion properties on critical surfaces can be achieved. In addition, the pigment wetting, flexibility and durability are improved.
Through skillful lowering of polarity also aliphatic tolerant urethane resins for offset inks with high hydrophobicity to adjust the water balance are available.
Furthermore the excellent adhesion properties of these resins allow for example in flexographic printing inks the reduction of other adhesion additives such as Titanates or Zirconates. Because of the wide compatibility with other binders like NC or PVB polyurethanes are commonly used in lacquers, priniting inks, especially in gravure and flexo inks as well as in adhesives.