There is increasing interest globally for water-based industrial paints. Water-based zinc rich primers are difficult to prepare due to the reactivity of zinc powder with water, evolving hydrogen gas. As a result, solvent-based materials are still widely used. QR Polymers has developed an innovative concept of a water-free water-based hardener: RD-0205WH which has been specifically developed for this application. The zinc is dispersed in the hardener which contains no water and is mixed with the water-based resin component containing other fillers and additives with additional water to the desired solids content before application. Dispersions of zinc powder in RD-0205WH are stable to settling and do not produce gas on prolonged storage even at elevated temperatures.
RD-0205WH is an isolated amine adduct supplied as 70% solids in propylene glycol n-butyl ether. RD-0205WH is miscible with water and is designed for use with modified or non-modified standard liquid epoxy as well as with liquid resin emulsions and solid resin dispersions (such as E‑Pos 1011W55). RD-0205WH has an easy 1:1 recommended mix ratio with standard liquid epoxy resin (EEW 190 g/eq).
An additional benefit of RD-0205WH is its inherent pseudoplastic nature, increasing the stability and resistance to settling of zinc rich paints with the zinc dispersed into RD‑0205WH without water. Water and the resin component are added immediately prior to application.
RD-0205WH exhibits high reactivity at ambient temperature and forms excellent films when cured with solid or liquid epoxy resins.