In modern coating systems, durability and gloss depend greatly on the hardener. For PU and industrial coatings, performance requirements are even stricter. The coating film must remain strong, chemical-resistant, and color-stable. Among polyisocyanate products, Desmodur N75 by Covestro is recognized as an industry benchmark. Thanks to its advanced structure, N75 creates a clear, tough, and long-lasting coating film.
DESMODUR N75 – CHARACTERISTICS AND STRUCTURE
Chemical composition
Desmodur N75 is an HDI-based polyisocyanate belonging to the non-yellowing isocyanate group. The product contains 75% solids dissolved in butyl acetate and xylene. Its NCO content of around 16.5% ensures strong reactivity with polyols, forming durable and stable urethane linkages. With low viscosity and excellent stability, N75 is easy to mix and apply in various formulations. The HDI trimer structure enhances UV resistance, prevents aging, and maintains flexibility under harsh conditions.
Reaction mechanism and technical advantages
When combined with polyols, the isocyanate groups of Desmodur N75 react with hydroxyl groups to form a three-dimensional urethane network. The coating thus gains high hardness while maintaining elasticity, resisting cracks under mechanical stress. N75 shows broad compatibility with polyester, acrylic, and alkyd resins, giving formulators flexibility in coating design. Its excellent moisture and solvent resistance make N75 a preferred hardener for coatings that require strong adhesion and long-term color stability.
APPLICATIONS OF DESMODUR N75 IN THE COATING INDUSTRY
Use in two-component PU coatings
In PU coatings, Desmodur N75 serves as the primary hardener, forming deep-gloss, chemical-resistant films with outstanding clarity. The cured coating remains tough, scratch-resistant, and non-yellowing even in demanding conditions.
On wood, plastic, or metal substrates, N75 provides balanced hardness and elasticity while drying quickly to save production time. Its UV and solvent resistance make it ideal for PU applications such as furniture coatings, automotive topcoats, synthetic leather finishes, and decorative surfaces.
Ứng dụng trong sơn công nghiệp
In industrial protection systems, Desmodur N75 is used with acrylic polyols to produce weather- and chemical-resistant films. The coating achieves high mechanical strength, resisting oil, fuel, and aggressive solvents. It is widely applied on metal structures, containers, steel frameworks, and industrial floors.
Even in outdoor or humid environments, N75 maintains coating clarity and surface hardness over time. Thanks to its durability and lasting gloss, Desmodur N75 is trusted in high-performance industrial coatings where both aesthetics and protection matter.
Explore Covestro’s premium coating materials officially distributed by Vichem:
VICHEM – EXCLUSIVE DISTRIBUTOR OF COVESTRO HARDENERS AND RESINS IN VIETNAM
Vichem is the exclusive distributor of Covestro products in Vietnam, including Desmodur, Desmophen, and Uralac. We not only supply certified products but also provide international-standard technical support.
- Technical consulting: Assisting customers in choosing suitable products for their coating systems.
- Color matching tests: Our technical team performs matching and evaluation to ensure design accuracy.
- Application support: Working closely with customers during production to achieve optimal performance.
For more information, please contact us through:
📞 Hotline: 08 1790 1790
📧 Email: contact@vichem.vn
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🌐 Website: www.vichem.vn
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