Bayhydur® XP 2655

Bayhydur® XP 2655 is a hydrophilic aliphatic polyisocyanate based on hexamethylene diisocyanate (HDI). It is used as a hardener for waterborne two-component polyurethane (2K-PUR) systems, providing excellent performance characteristics in coatings and adhesives.

Key Characteristics:

• Form Supplied: 100% solid.
• Viscosity at 23 °C: 3,500 ± 1,000 mPa·s (M014-ISO 3219/A.3).
• NCO Content: 20.3 - 21.3% (M105-ISO 11909).
• Hazen Color Value: < 60 (M017-EN 1557).
• Monomeric HDI: ≤ 0.24% (M106-ISO 10283).

Additional Data:

• Flash Point: Approximately 192 °C (DIN EN ISO 2719).
• Density: Approximately 1.16 g/cm³ (DIN EN 2811).

Properties and Applications

Bayhydur® XP 2655 is utilized as a crosslinking agent in waterborne systems where reliable incorporation and high chemical resistance are required. Its moderate hydrophilicity allows it to be easily dispersed in aqueous phases with minimal shear force, making it suitable for trade applications.

• Coating Performance: Coatings made with Bayhydur® XP 2655 exhibit high gloss and low haze. They dry quickly, harden rapidly, and achieve high ultimate hardness with excellent chemical resistance.
• Solvent Compatibility: Compatible with various organic solvents such as esters and ethers, though compatibility and influence on emulsibility should be tested for each specific solvent.
• Application Versatility: Suitable as a crosslinking partner for waterborne polyol binders (e.g., Bayhydrol®) and for pH-neutral waterborne polymer dispersions (e.g., polyurethane, polyvinyl acetate, polyacrylate, synthetic rubber).

Storage and Handling

• Storage Conditions: Store in original sealed containers at 0 - 30 °C, protected from moisture, heat, and contaminants.
• Moisture Sensitivity: Highly sensitive to moisture, which can lead to the formation of carbon dioxide and insoluble ureas. This can cause dangerous pressure increases if moisture enters the container.