Under the product name Rokrapol, Robert Kraemer GmbH & Co. KG produces caroxyl functional (sour) polyester. These polyester resins have a high carboxyl functionality as well as other OH-groups and depending on the application area, they are linar and therefore flexible and branched and partially specifically modified. The main application areas for this sour binder are printing inks, lacquers (i.e. NC lacquers, enamel, paper lacquers, spraying varnish), adhesives or inks (also ink jets). Because of the carboxyl functionality, the resins can be netralized and afterwards dissolved in water or disperged unneutralized. In aqueous dispersions, the sour polyester are mainly suitable for improvement of gloss (gloss resin). Furthermore, the carboxyl functionality optimizes adhesion on a few critical surfaces, especially metal.
Polyester by Robert Kraemer are available in standard dissolvents (i.e. Ethanol), as special solvents or also 100%). Solid hard resins as well as aqueous (viscous) soft resins are available in the product range. Properties worth mentioning are gloss, good adhesion, a very light color, light resistance as well as flexibility and/or hardness (depending on the degree of branching).