Under the GCC's extreme UV radiation and temperature cycling, aliphatic PU topcoats maintain gloss, colour, and film integrity far longer than epoxy or aromatic urethane alternatives — making them the standard for high-performance architectural and industrial topcoats in UAE and Saudi Arabia.
Technical specifications
| PARAMETER | SPECIFICATION | TEST METHOD |
|---|---|---|
| Chemical Class | Aliphatic polyisocyanate (HDI trimer / IPDI) | — |
| Available Grades | 75% in solvent (BA or xylene) and 100% solids | — |
| Appearance | Clear to slightly yellow liquid | Visual |
| NCO Content | 16 – 23 % (grade dependent) | ASTM D2572 |
| Viscosity @ 25°C | 800 – 4,000 mPa·s (100% grade) | ASTM D445 |
| Density @ 25°C | 1.05 – 1.20 g/cm³ | ASTM D4052 |
| Equivalent Weight (NCO) | 183 – 262 g/eq | Calculated |
| Moisture Content | < 0.05 % | Karl Fischer |
| Flash Point (100% grade) | > 110°C | ASTM D93 |
| Shelf Life | 24 months sealed, dry, 15–25°C | — |
| HS Code | 2929.10 |
Applications
- UV-Stable Industrial & Architectural Topcoats — Part B (hardener) in two-component polyurethane topcoat systems for structural steel, facades, and industrial structures across UAE and Saudi Arabia. Aliphatic systems retain gloss and colour for 5–10 years under GCC UV conditions vs 1–2 years for epoxy topcoats.
- High-Performance Maintenance Coatings — Used in high-build PU topcoats for maintenance painting of bridges, cranes, industrial structures, and infrastructure across the GCC — providing maximum service life in corrosive, high-UV environments.
- Automotive Refinish & Transport Coatings — Component in premium two-component PU refinish systems for commercial vehicles, trailers, and transport equipment operated across UAE and Saudi Arabia.
- Architectural Metal Coatings — Used in factory-applied coatings for aluminium cladding, curtain wall systems, and architectural metalwork for buildings in Dubai, Abu Dhabi, and Riyadh.
- Protective Topcoats for Oil & Gas Infrastructure — Combined with epoxy primer systems as UV-stable, colour-retentive topcoats on above-ground pipelines, storage tanks, and process equipment exposed to intense Saudi Arabian and UAE sunlight.
Key properties
- Outstanding UV resistance — no yellowing or chalking in GCC sunlight
- Excellent gloss retention over extended exterior service
- High abrasion and scratch resistance in cured film
- Good chemical resistance
- Can be pigmented to any colour with stable hue retention
- Compatible with acrylic polyols (Part A) for standard 2K PU systems
- Very low moisture tolerance — strict dry conditions required
- NCO groups react with atmospheric moisture — keep sealed at all times
Usage and recommendations
Use with compatible acrylic or polyester polyols (Part A). Mix ratio calculated from NCO equivalent weight of isocyanate and OH equivalent weight of polyol — typically 1:1 to 1:2 by equivalent. Store under nitrogen or dry inert gas — isocyanates react with moisture to form CO₂ (bubbles in film) and urea (haze). In GCC summer heat, pot-life of mixed system is reduced significantly — mix only what can be applied within the working pot-life. Aliphatic isocyanates require full PPE — NIOSH-approved respiratory protection, nitrile gloves, and eye protection mandatory. Vapour is harmful if inhaled. Contact Raykem for specific grade recommendation and mix ratio calculation.
Packaging
- 200 kg Steel Drum (nitrogen-blanketed)
- IBC 950–1,000 kg
- Custom packaging on request
Storage and shelf life
Store in nitrogen-blanketed sealed containers at 15–25°C in a dry (< 50% RH), cool, covered warehouse away from moisture, heat, and ignition sources. Do not store at temperatures above 40°C. Shelf life: 24 months from manufacture in original sealed containers. Partially used containers must be resealed under dry inert gas immediately.