Desmodur® L 75

Desmodur® L 75 is an aromatic polyisocyanate resin derived from toluene diisocyanate (TDI). It is primarily used as a hardener component for formulating two-component polyurethane coatings and adhesives when combined with various hydroxyl-bearing substances like Desmophen®, Baycoll®, Desmocoll® grades, or others.

Key specifications and properties include:

• NCO Content: 13.3 ± 0.4%
• Non-volatile Content: 75.0 ± 2.0%
• Viscosity at 23°C: 1,600 ± 400 mPa·s
• Color (Iodine): ≤ 2
• Monomer Content: < 0.5%
• Equivalent Weight: Approximately 315
• Flash Point: Approximately 5°C
• Density at 20°C: Approximately 1.17 g/ml

Desmodur® L 75 demonstrates good compatibility with various solvents such as ethyl acetate, butyl acetate, 1-methoxypropylacetate-2, toluene, xylene, Solvesso 100, and Shellsol® A. However, solutions formed should be tested for their storage stability. It is incompatible with aliphatics, and alcohols should be avoided due to their reactivity with Desmodur® L 75.

In addition to coatings for furniture, flooring, metal, paper, plastics, and mineral substrates, Desmodur® L 75 is suitable for room-temperature crosslinking of adhesives based on Desmocoll® or Baycoll®, enabling bonding of various materials such as wood, metal, and plastic. The resin enhances the resistance of bonds to heat, oil, plasticizers, and many solvents, ensuring good adhesion, especially to plastics. Its pale color allows for bonding transparent plastic films for packaging applications.

Proper storage involves keeping Desmodur® L 75 in its original sealed container at temperatures between 0°C and 30°C, protected from moisture, heat, and foreign materials. Storage at higher temperatures may lead to increased color and viscosity, while significantly lower temperatures may cause solidification, which is reversible by brief heating without affecting product quality.

Like other polyisocyanate resins, Desmodur® L 75 is primarily used in industrial or trade applications and requires appropriate protective measures outlined in the safety data sheet. It is not recommended for DIY applications.