Desmodur N 3300 is an aliphatic polyisocyanate based on hexamethylene diisocyanate (HDI) trimer, supplied by Thousands Technology as a curing agent for light-stable two-component polyurethane coating systems. Formulated as a solvent-free resin with an NCO content of 21.8 ± 0.3%, this curing agent is designed to deliver strong chemical resistance, weatherability, and gloss retention when cross-linked with a suitable polyacrylate or polyester polyol.
Desmodur N 3300 Key Properties
Per the manufacturer product data sheet, Desmodur N 3300 has an NCO content of 21.8 ± 0.3% (DIN EN ISO 11909), a viscosity at 23°C of 3000 ± 750 mPa·s (DIN EN ISO 3219/A.3), a color value of ≤ 40 Hazen (DIN EN 1557), and an HDI monomer content of < 0.15% (DIN EN ISO 10283). Additional reference data include a viscosity of approximately 2500 mPa·s at 25°C, an equivalent weight of approximately 193, a flash point of approximately 228°C (DIN 22719), and a density at 20°C of approximately 1.16 g/ml (DIN EN ISO 2811). Chemically, this curing agent is based on the HDI isocyanurate trimer structure (CAS 28182-81-2), which can be reviewed on PubChem.
As a solvent-free resin, it requires no additional diluent before formulation, which helps coating producers manage VOC content while still achieving workable viscosity. Its light-stable aliphatic backbone distinguishes it from aromatic isocyanates, giving cured films resistance to yellowing and chalking under UV exposure, which is why it remains a standard choice for exterior-exposed coating systems.
Key Features
- Light-stable aliphatic HDI trimer chemistry for excellent weatherability
- Strong chemical resistance and gloss retention in cured films
- Solvent-free form supporting low-VOC formulation
- Compatible with polyacrylate and polyester polyol co-reactants
- Low free HDI monomer content (< 0.15%)
Main Applications of Desmodur N 3300
Desmodur N 3300 is mainly used as the curing agent component in light-stable two-component polyurethane coatings. Coating systems based on this HDI trimer serve OEM automotive coatings, automotive refinish, transportation equipment, and industrial and plastics coating. Formulators building a complete 2K PU system can pair it with Thousands Technology’s auxiliary agent range alongside a suitable polyester or acrylic polyol to match the required pot life and film performance.
Because two-component coating production depends on consistent NCO content, viscosity, and reactivity from batch to batch, industrial buyers sourcing Desmodur N 3300 typically request a current technical data sheet before scaling up purchase volumes and maintain a qualified secondary supply channel to protect production schedules from single-source disruptions.
Safety and Handling Considerations
As with other isocyanate-based curing agents, this product should be handled with appropriate personal protective equipment and adequate ventilation, since isocyanates can cause respiratory and skin sensitization on repeated or prolonged exposure. It should be stored in tightly sealed containers, protected from moisture, since isocyanates react with water. A Safety Data Sheet is available on request, and Thousands Technology can supply the current TDS and SDS alongside each order.
Frequently Asked Questions About Desmodur N 3300
- What is Desmodur N 3300 used for? It is used as a curing agent for light-stable two-component polyurethane coatings across OEM automotive, automotive refinish, transportation, and industrial and plastics coating applications.
- What is the NCO content of this curing agent? Per the manufacturer data sheet, it has an NCO content of 21.8 ± 0.3%.
- What is the viscosity of this HDI trimer? At 23°C, viscosity is 3000 ± 750 mPa·s per DIN EN ISO 3219/A.3.
- What co-reactants work best with Desmodur N 3300? The manufacturer identifies polyacrylate and polyester polyols as the best co-reactants for this curing agent.
- Can Thousands Technology supply this material in bulk? Yes, Thousands Technology offers supply chain resource support for bulk orders of Desmodur N 3300, with standard industrial packaging and TDS/SDS available on request.
Coating formulators evaluating this curing agent for an upcoming two-component polyurethane production run are welcome to contact Thousands Technology for current availability, packaging options, and documentation to support their sourcing decision.
