White High-Gloss 2K Polyurethane Topcoat for Automotive Utilizing 5.3.

This formulation describes an aqueous white two-pack polyurethane (PU) topcoat for automotive coatings. It's based on Bayhydrol A 145 and Bayhydur 304. Here's a summary without percentages:

Components:

• Component 1: Bayhydrol A 145, Surfynol 104 BC, Borchi® Gel PW 25, Borchi® Gol LA 200, Borchi® Gen 0851, Sachtleben R-KB-4.
• Component 2: Bayhydur 304, Dipropylene glycol DME.
• Water (for thinning).

Indications:

• Application involves placing Component 1 in a mixing vessel, stirring in components 2-5, pre-dispersing, dispersing in a bead mill, and deaerating.
• Compressed-air spraying with a 1.3 mm nozzle is recommended, followed by intermediate and final deaeration.
• A light stabilizer (Tinuvin 292) should be added before Component 2.

Technical Data:

• NCO: OH - ratio is 1.5.
• Ratio of Component 1 to Component 2: 4.52:1.
• Flow time: 25 seconds (DIN 53211-cup 4 mm, at 23 °C).
• Cosolvent: 7.6%.
• Density: 1.3 kg/l.
• VOC: 118 g/l.
• pH-value: 8.1.
• Solids content on application: 58%.

Technical Properties:

• Chemical resistance against various substances, evaluated based on test surfaces.
• Drying time: 30 minutes at 60 °C.
• Pendulum hardness: 2 hours: T1 (soft), 7 hours: T3 (hard).
• Film thickness: 73 µm (1 day at room temperature), 121 µm (7 days at room temperature and 16 hours at 50°C).
• Gloss: 78 at 20° angle, visually: 1.
• Haze: 39.

Suppliers:

• Covestro, Air Products, Milliken, Sachtleben, Clariant.