KF-PU500 acrylic polyurethane topcoat is a two-component high-weathering topcoat based on hydroxyl-containing acrylic resin with aliphatic isocyanate (HDI trimer) as the hardener. The use of an aliphatic hardener is the key to ensuring the coating does not yellow over time — aromatic hardeners are cheaper but yellow. The coating offers excellent outdoor weathering resistance (QUV-B 3000h, ΔE<3), gloss and colour retention, and chemical resistance. It is the standard companion topcoat over epoxy zinc-rich primer + epoxy MIO intermediate coat in C4/C5 corrosive environments, and is also widely used in industrial coating fields requiring high decoration + high weather resistance.
TDS Technical Data Sheet – Polyurethane Acrylic Topcoat KF-PU500
Technical Data Sheet · Polyurethane acrylic topcoat · KF-PU500
1. Product Description
2. Typical Applications
Matching topcoat for heavy-duty anticorrosion coating systems on bridges, steel structures, petrochemical plants and offshore platforms; topcoat for construction machinery, mining machinery, agricultural machinery and port machinery; topcoat for wind turbine towers and photovoltaic mounting structures; topcoat for architectural steel structures, curtain walls and aluminum profiles; topcoat for railway vehicles and containers.
3. Technical Parameters
| Product type | Two-component solvent-based acrylic polyurethane topcoat |
|---|---|
| Color | Full colour range (RAL/PANTONE/Munsell) |
| Gloss | High gloss (>85 GU)/semi-gloss/matte |
| Volume solids | 55±3% |
| Recommended DFT | 30–50 μm/coat |
| Theoretical spreading rate | 11-18 m²/L(50μm) |
| Mixing ratio | A:B=4:1 (by weight) |
| Pot life | 4h(20°C) |
| Surface dry time (23°C) | ≤1h(23°C) |
| Hard dry time (23°C) | ≤12h(23°C) |
| Min. overcoat interval | 4 h (23°C); max. 48 h |
| Full cure | 7 days (23°C) |
| Application temperature | 5-40°C |
| Relative humidity | <80% |
| Flash point (closed cup) | Approx. 24°C |
| Density (mixed) | approx. 1.2 kg/L |
| VOC content | <420 g/L |
| Adhesion | Grade 0–1 |
| Packaging Specs | 20 L drum |
| Shelf Life | 12 months |
| Salt spray resistance | ≥1000h |
| Accelerated weathering resistance | ΔE<3 / gloss retention >80% |
| Standard | HG/T 2454 / AAMA 2605 |
| Product type | Two-component aliphatic acrylic polyurethane topcoat (high weatherability) |
| Hardener type | Aliphatic isocyanate HDI trimer (non-yellowing) |
4. Application Guide
Surface preparation
Thoroughly clean the substrate surface to remove oil and rust. Abrasive-blast steel to Sa2.5 (ISO 8501-1) with 40-75μm surface profile. Concrete substrate moisture content must be below 6%, grind to remove laitance. For old coatings, remove loose areas and roughen the surface.
Mixing / compounding
According to the mix ratio indicated on the product label, add the hardener (component B) slowly to the base (component A) and mechanically stir for 3-5 minutes until uniform. Let stand to mature for 10-15 minutes before use. Use up within the specified pot life after mixing.
Application method
Recommended air spray (gun orifice 1.5-2.0 mm, pressure 0.4-0.6 MPa) or airless spray (nozzle 0.38-0.53 mm, pressure 15-25 MPa). Small areas may be brushed or rolled. Keep each coat dry film thickness within the specified range.
Curing conditions
Self-cures at ambient temperature (23°C) provided relative humidity meets requirements. Do not apply under low temperature (<5°C) or high humidity (>85%). Conduct performance testing only after full cure.
5. Packaging & Storage
| Packaging Specs | 20 L drum |
|---|---|
| Storage Conditions | Store at 5–35°C in a cool, dry, ventilated place away from ignition and heat sources; keep container sealed. |
| Shelf Life | 12 months |
| Transport | Transport as non-hazardous goods. In summer, ship in early morning or evening; avoid sun exposure. |
6. Health & Safety Notes
⚠️ Important safety notice
Read and understand the product's MSDS (Material Safety Data Sheet) carefully before using this product.
- Proper personal protective equipment (gloves, goggles, protective suit) must be worn during application
- Ensure the work area is well ventilated
- Keep away from fire and heat sources
- Avoid inhaling vapours and mist
- Avoid contact with skin and eyes
- If you feel unwell, stop work immediately and seek medical advice
Disclaimer
The data in this TDS are typical values and do not constitute product specifications. Actual product performance may vary depending on application conditions, substrate condition and environmental factors. Users are advised to conduct small-scale sample tests before bulk use to confirm product suitability.
Kexin New Materials continuously improves its products and reserves the right to modify technical parameters without prior notice. For the latest version please visit www.psste.com/polyurethane-acrylic-topcoat-tds/ page.
⬇ Download this document (PDF)
Related articles & news
Further reading: technical articles and industry news from Kexin New Materials