Desmodur® VL 50

Desmodur® VL 50 is a specific type of aromatic polyisocyanate based on diphenylmethane diisocyanate (MDI). Here's a detailed breakdown of its characteristics, applications, and specifications:

Characterization:

• Chemical Type: Aromatic polyisocyanate
• Base: Diphenylmethane diisocyanate (MDI)

Form Supplied:

• Appearance: Brown liquid of low viscosity

Specifications:

• NCO Content: 32.5 ± 1.0%
• Viscosity at 25°C: 22.5 ± 7.5 mPa·s
• Acidity (as HCl): ≤ 600 mg/kg
• Equivalent Weight: 129
• Flash Point: > 200°C
• Density at 20°C: Approx. 1.22 g/ml

Compatibility:

Desmodur® VL 50 is compatible with various hydroxyl-bearing polyesters and polyethers, making it suitable for formulating:

• Self-leveling, two-component polyurethane coating and sealing compounds
• Two-component polyurethane primers and thin-coat finishes

Properties and Applications:

• Flexibility: When combined with suitable polyols like Desmophen® grades or castor oil-based polyols, it enhances flexibility and reduces mixing viscosity.
• Water Sensitivity: Requires a water scavenger (like molecular sieve paste® 3 Å) in the polyol component to prevent undesired reactions with moisture.

Storage and Handling:

• Storage Conditions: Store in original sealed containers at temperatures between 10°C and 30°C. Protect from moisture, heat, and foreign materials.
• Shelf Life: The product is sensitive to moisture; storage conditions must be strictly adhered to for optimal performance.

Safety and Regulatory Information:

• Transport Classification: Not explicitly mentioned in the datasheet, but typically classified for transport under specific hazardous material guidelines.
• Safety Data Sheet: Essential for safe handling, providing detailed information on handling precautions, emergency procedures, and disposal.

Desmodur® VL 50 is particularly valued in coatings and sealants for its ability to impart durability, flexibility, and chemical resistance, typical of polyurethane-based systems. Its use requires careful attention to formulation details and storage conditions to ensure product integrity and performance.