Epoxy Hardeners (Phenalkamines)
Phenalkamines are synthesized from Cashew nut shell liquid combining the properties of aliphatic amines and polyamides which are characteristic of low toxicity, good flexibility and good chemical resistance.
Structure-to-property Relationship
- The aromatic backbone is responsible for the high chemical resistance.
- The side chain is very hydrophobic & can make these resins water resistant; the phenolic OH group makes phenalkamines very active even at low temperatures.
- The amine side is responsible for the high cross linking density.
- These curing agents can have a low viscosity (for low VOC purposes) and high chemical activity.
The fast and low temperature cure properties of phenalkamines have a number of benefits for coating formulations. Application productivity can be significantly improved and the ability to apply a coating in low temperatures allows for a longer or even year round painting season. Faster cure also means protected surfaces can be re-coated or returned to service more rapidly, including solvent free formulations that will continue to cure when immersed in water & solvent based coatings that will continue to cure in poorly ventilated conditions. In forced cure industrial coating applications, Phenalkamines can help save energy by lowering oven cure temperatures, or improving process efficiency via increased production line speeds. Finally, fast cure can also help protect coating manufacturers from coating failures. By reaching a high level of cross linking very quickly, coatings develop their stability early and avoid problems when the environmental conditions change after application.
The high hydrophobicity of Phenalkamines provided by the long linear side chain also brings many benefits to coating formulations compared with some other technologies. Water sensitivity of the phenolic hydroxyl and other formulation components can be counteracted, which reduces the chance the resin binder barrier will be broken and increases corrosion protection. Adhesion to poorly prepared or tough wet surfaces, such as water saturated concrete is especially good with phenalkamines because this hydrophobic effect ensures surrounding water does not influence the surface resin bond.
Benefits
- Outstanding Water Resistance
- Superior Corrosion Resistance
- VOC Compliant - solvent free
- Low Migration Levels
- Faster Recoat - Phenalkamines offer rapid cure with no induction time, reducing costly downtime.
- All Season Cure - With phenalkamines, a coating can provide fast cure at low temperatures (~40°F) & ambient temperatures and do it without sacrificing pot life.
- Outstanding Surface Tolerance - Phenalkamines provide good adhesion to less than perfectly prepared surfaces, including rusty, cold, wet or damp surfaces.
- Application Independent of Weather Conditions - Temperature, humidity, dew point.