Bayhydrol® UH 650

Bayhydrol® UH 650 is a solvent-free, aliphatic polyurethane resin dispersion designed for use in coatings, particularly in two-coat systems for plastics and soft-touch coatings. Here’s a detailed overview:

Product Overview:

• Product Name: Bayhydrol® UH 650
• Type: Aliphatic polyurethane resin dispersion
• Form Supplied: Approximately 50% in water

Specifications:

• Efflux Time at 23°C (4 mm cup): 12 - 30 seconds (AFAM 2008/105 03)
• Non-Volatile Content (1 g/1 h/125°C): 48 - 52% (DIN EN ISO 3251)
• pH: 6 - 8 (DIN ISO 976)
• Density at 20°C: Approximately 1.1 g/ml (DIN EN ISO 2811)
• Minimum Film Forming Temperature (MFT): < 0°C (DIN ISO 2115)

Properties / Applications:

• Adhesion and Performance:
  • When used in two-layer systems with two-component polyurethane clearcoats, it provides good adhesion to various plastics.
  • Offers good overcoatability and water resistance.
  • Can be used for metallic basecoats, which can be oversprayed with a two-component polyurethane clearcoat after pre-drying.
• Drying and Compatibility:
  • Predrying: For instance, 5 minutes at 80°C ambient temperature or 15 minutes at room temperature.
  • Forced Drying: Possible at temperatures as low as 60°C.
  • Compatible with water-thinnable polyesters and some acrylic dispersions. Compatibility testing with other resins is recommended.

Storage:

• Recommended Storage Temperature: 5 - 30°C.
• Protect From: Frost, heat, and contamination with foreign material.
• Homogenization: Slight sedimentation may occur; mix thoroughly before use.
• Freezing: The product is sensitive to frost. Freezing will damage it irreversibly.
• High Temperature Storage: Prolonged storage at higher temperatures may affect viscosity and particle size.

Storage Time:

• Covestro guarantees that the product will meet the specifications for six months from the shipment date if stored under the recommended conditions.
• After six months, the product should be tested for specifications before use, as Covestro does not guarantee performance beyond this period.